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Y^(3+) substituting-adjusted mechanical,dielectric,and impedance properties of cobalt copper zinc nanoferrites for high frequency applications

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Journal of Rare Earths 2023年第10期41卷 1597-1605,I0005页

作者： s.F.Mansour n.s.al-bassami M.Afifi M.A.Abdo Physics Department Faculty of ScienceZagazig UniversityZagazigEgypt General studies Department Jubail Industrial CollegeJubail Industrial CitySaudi Arabia Faculty of nanotechnology for Postgraduate studies Cairo UniversityEl-Sheikh Zayed12588Egypt

Upgrading mechanical-dielectric features of ferrites through rare-earth yttrium(Y^(3+))doping provides feasibility to evolving high-frequency electronic devices.This paper reports the mechanical and dielectric properties of Co_(0.5)Cu_(0.25)Zn_(0.25)Y_(x)Fe_(2-x)O_(4)ferrite nanoparticles labeled as CCZYF#0,CCZYF#1,CCZYF#2,CCZYF#3,CCZYF#4 and CCZYF#5 for x=0.***.0.02,0.04,0.06,0.08,and 0.1,respectively.The frequency and temperature dependence of dielectric parameters and co nductivity of all CCZYF nanoferrites are well discussed.The nanoferrite CCZYF#5 has the highest dielectric constant(enhancing ratio 170%)and the highest conductivity(enhancing ratio 7125.81%)compared with the undoped sample.nyquist plots of all CCZYF nano ferrites manifest two arcs;the main reasons for the dielectric process are the grain boundaries and bulk grains.all impedance parameters were determined,which showed the effective role of Y^(3+)ions on their values.The nanoferrite CCZYF#5 has the highest grain boundaries capacitance(with enhancing ratio of 59.40%)and the highest grains capacitance(with enhancing ratio of 22.53%)with a relaxation time decrement efficiency of 62.51%.An ultrasonic flaw detector was utilized to determine the elastic moduli of all CCZYF nanoferrites.The nanoferrite CCZYF#5 has the highest longitudinal modulus(with enhancing ratio of 20.95%),the highest shear modulus(with enhancing ratio of48.72%),highest Young's modulus(with enhancing ratio of 88.47%),the highest bulk modulus(with enhancing ratio 13.27%)and the highest micro hardness(with enhancing ratio 77.77%).Hence,Y3+tuned Co-Cu-Zn nanoferrites possess new opportunities for high-frequency and storage applications.

关键词： nanoferrites Rare arth ions Mechanical properties Dielectric parameters Impedance spectroscopy

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The Lambert-G Family:Properties,Inference,and Applications

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Computer Modeling in Engineering & sciences 2024年第7期140卷 513-536页

作者： Jamal n.al Abbasi Ahmed Z.Afify Badr alnssyan Mustafa s.shama Accounting Department Ashur UniversityBaghdad10011Iraq Department of statistics Mathematics and InsuranceBenha UniversityBenha13511Egypt Department of Management Information systems and Production Management College of Business and EconomicsQassim UniversityBuraydah51452Saudi Arabia Department of Basic sciences Common First Year(CFY)King Saud UniversityRiyadh11362Saudi Arabia Department of Mathematics and statistics Osim Higher Institute of Administrative ScienceOsim12961Egypt

This study proposes a new flexible family of distributions called the Lambert-G family.The Lambert family is very flexible and exhibits desirable properties.Its three-parameter special sub-models provide all significantmonotonic and non-monotonic failure rates.A special sub-model of the Lambert family called the Lambert-Lomax(LL)distribution is investigated.General expressions for the LL statistical properties are established.Characterizations of the LL distribution are addressed mathematically based on its hazard function.The estimation of the LL parameters is discussed using six estimation methods.The performance of this estimation method is explored through simulation experiments.The usefulness and flexibility of the LL distribution are demonstrated empirically using two real-life data sets.The LL model better fits the exponentiated Lomax,inverse power Lomax,Lomax-Rayleigh,power Lomax,and Lomax distributions.

关键词： Lambert function Lomax distribution maximum likelihood hazard function statistical model simulation

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Previously undiagnosed Morgagni hernia with bowel perforation detected during repeat screening colonoscopy: A case report

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World Journal of Clinical Cases 2024年第14期12卷 2389-2395页

作者： said al alawi alan n Barkun sara najmeh Division of Gastroenterology McGill UniversityMontrealQC H4A 3J1Canada Division of Thoracic surgery McGill UniversityMontrealQC H4A 3J1Canada

BACKGROUnD Morgagni hernia(MH)is a form of congenital diaphragmatic hernia(CDH)characterized by an incomplete formation of diaphragm,resulting in the protru-sion of abdominal organs into the thoracic cavity.The estimated incidence of CDH is between 1 in 2000 and 1 in 5000 live births,although the true incidence is unknown.MH typically presents in childhood and can be diagnosed either pre-natally or postnatally.However,it can also be asymptomatic and carry the risk of developing into a life-threatening condition in adulthood.CAsE sUMMARY A 76-year-old female with no history of prior abdominal surgeries presented for an elective colonoscopy for polyp surveillance.During the procedure,when approaching the hepatic flexure,the scope could not be advanced further despite multiple attempts.The patient experienced mild abdominal discomfort,leading to the abortion of the procedure.While in the recovery area,she developed increa-sing abdominal pains and hypotension.Urgent abdominal imaging revealed her-niation of the proximal transverse colon through a MH into the chest with evi-dence of perforation.The patient underwent laparoscopic urgent colonic resection and primary hernia repair and was discharged uneventfully 2 d later.COnCLUsIOn A MH is a rare condition in adults that can present as a life-threatening compli-cation of colonoscopy,even in patients with a history of uneventful colonoscopies.This case highlights the importance of considering congenital and internal hernias when faced with sudden and unexplained difficulties during colonoscopy.If there is a suspicion of MH,the endoscopist should halt the procedure and immediately obtain abdominal imaging to confirm the diagnosis.

关键词： Bowel perforation Colonoscopy Adverse event Congenital diaphragmatic

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Astrophysical s-factor and reaction rate for 15n(p,γ)16O within the modified potential cluster model

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Chinese Physics C 2024年第4期48卷 130-145页

作者： s.B.Dubovichenko A.s.Tkachenko R.Ya.Kezerashvili n.A.Burkova B.M.Yeleusheva Fesenkov Astrophysical Institute 050020 AlmatyKazakhstan new York City College of Technology City University of New YorkBrooklyn11201 New YorkUSA Graduate school and University Center City University of New York10016 New YorkUSA al-Farabi Kazakh national University 050040 AlmatyKazakhstan

We study radiative p^(15)n capture on the ground state of ^(16)O at stellar energies within the framework of a modified potential cluster model(MPCM)with forbidden states,including low-lying resonances.The investigation of the ^(15)n(p,γ0)^(16)O reaction includes the consideration of ^(3)s_(1) resonances due to E1 transitions and the contribution of the ^(3)P_(1) scattering wave in the p+^(15)n channel due to the ^(3)P_(1)→^(3)P_(0)M1 transition.We calculated the astrophysical low-energy s-factor,and the extrapolated s(0)turned out to be within 34.7−40.4 keV·b.The important role of the asymptotic constant(AC)for the ^(15)n(p,γ0)16O process with interfering ^(3)s_(1)(312)and ^(3)s_(1)(962)resonances is elucidated.A comparison of our calculation for the s-factor with existing experimental and theoretical data is addressed,and a reasonable agreement is found.The reaction rate is calculated and compared with the existing rates.It has negligible dependence on the variation of AC but shows a strong impact of the interference of ^(3)s_(1)(312)and ^(3)s_(1)(962)resonances in reference to the CnO Gamow windows,especially at low temperatures.We estimate the contribution of cascade transitions to the reaction rate based on the exclusive experimental data from Phys.Rev.C.85,065810(2012).The reaction rate enhancement due to the cascade transitions is observed from T_(9)>0.3 and reaches the maximum factor~1.3 at T_(9)=1.3.We present the Gamow energy window and a comparison of rates for radiative proton capture reactions ^(12)n(p,γ)^(13)O,^(13)n(p,γ)^(14)O,^(14)n(p,γ)^(15)O,and ^(15)n(p,γ)^(16)O obtained in the framework of the MPCM and provide the temperature windows,prevalence,and significance of each process.

关键词： low and astrophysical energies p^(15)n system thermonuclear reaction rate potential cluster model CnO-cycle

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Dynamic and electrical responses of a curved sandwich beam with glass reinforced laminate layers and a pliable core in the presence of a piezoelectric layer under low-velocity impact

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 155-178页

作者： n.sHAHVEIsI s.FELI Department of Mechanical Engineering Razi UniversityKermanshah ***Iran

The dynamic responses and generated voltage in a curved sandwich beam with glass reinforced laminate(GRL)layers and a pliable core in the presence of a piezoelectric layer under low-velocity impact(LVI)are investigated.The current study aims to carry out a dynamic analysis on the sandwich beam when the impactor hits the top face sheet with an initial velocity.For the layer analysis,the high-order shear deformation theory(HsDT)and Frostig's second model for the displacement fields of the core layer are used.The classical non-adhesive elastic contact theory and Hunter's principle are used to calculate the dynamic responses in terms of time.In order to validate the analytical method,the outcomes of the current investigation are compared with those gained by the experimental tests carried out by other researchers for a rectangular composite plate subject to the LVI.Finite element(FE)simulations are conducted by means of the ABAQUs software.The effects of the parameters such as foam modulus,layer material,fiber angle,impactor mass,and its velocity on the generated voltage are reviewed.

关键词： analytical model piezoelectric layer curved sandwich beam glass reinforced laminate(GRL) pliable core low-velocity impact(LVI) classical non-adhesive elastic contact theory

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Flow Regimes in Bubble Columns with and without Internals: A Review

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Fluid Dynamics & Materials Processing 2024年第2期20卷 239-256页

作者： Ayat n.Mahmood Amer A.Abdulrahman Laith s.sabri Abbas J.sultan Hasan shakir Majdi Muthanna H.al-Dahhan Department of Chemical Engineering University of Technology-IraqBaghdadIraq Chemical and Petroleum Industries Engineering Department Al-Mustaqbal University CollegeBabylonIraq Department of Chemical and Biochemical Engineering Missouri University of Science and TechnologyRollaUSA

Hydrodynamics characterization in terms ofﬂow regime behavior is a crucial task to enhance the design of bubble column reactors and scaling up related methodologies.This review presents recent studies on the typicalﬂow regimes established in bubble columns.some effort is also provided to introduce relevant deﬁnitions pertaining to thisﬁeld,namely,that of“void fraction”and related(local,chordal,cross-sectional and volumetric)variants.Experimental studies involving different parameters that affect design and operating conditions are also discussed in detail.In the second part of the review,the attention is shifted to cases with internals of various types(perfo-rated plates,bafﬂes,vibrating helical springs,mixers,and heat exchanger tubes)immersed in the bubble columns.It is shown that the presence of these elements has a limited inﬂuence on the global column hydrodynamics.However,they can make the homogeneousﬂow regime more stable in terms of transition gas velocity and transi-tion holdup value.The last section is used to highlight gaps which have not beenﬁlled yet and future directions of investigation.

关键词： Hydrodynamics ﬂow regime bubble column heat-exchanging internals

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Chiral transmission by an open evolution trajectory in a non-Hermitian system

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Light(science & Applications) 2024年第4期13卷 628-636页

作者： Xiaoqian shu Qi Zhong Kai Hong Oubo You Jian Wang Guangwei Hu Andrea alù shuang Zhang Demetrios n.Christodoulides Lin Chen Wuhan national Laboratory for Optoelectronics and school of Optical and Electronic Information Huazhong University of Science and TechnologyWuhan 430074China. Zhejiang Lab Hangzhou 311121China. CREOL College of Optics and PhotonicsUniversity of Central FloridaOrlandoFlorida 32816USA. Department of Physics The University of Hong KongHong KongChina. school of Electrical and Electronic Engineering Nanyang Technological University50 Nanyang AvenueSingapore 639798Singapore. Photonics Initiative Advanced Science Research CenterCity University of New YorkNew YorkNY 10031USA. shenzhen Huazhong University of science and Technology Research Institute Shenzhen 518063China

Exceptional points(EPs),at which two or more eigenvalues and eigenstates of a resonant system coalesce,are associated with non-Hermitian Hamiltonians with gain and/or loss elements.Dynamic encircling of EPs has received significant interest in recent years,as it has been shown to lead to highly nontrivial phenomena,such as chiral transmission in which the final state of the system depends on the encircling handedness.Previously,chiral transmission for a pair of eigenmodes has been realized by establishing a closed dynamical trajectory in parity-time-(PT-)or anti-PT-symmetric systems.although chiral transmission of symmetry-broken modes,more accessible in practical photonic integrated circuits,has been realized by establishing a closed trajectory encircling EPs in anti-PTsymmetric systems,the demonstrated transmission efficiency is very low due to path-dependent losses.Here,we demonstrate chiral dynamics in a coupled waveguide system that does not require a closed trajectory.specifically,we explore an open trajectory linking two infinite points having the same asymptotic eigenmodes(not modes in PT-and anti-PT-symmetric systems),demonstrating that this platform enables high-efficiency chiral transmission,with each eigenmode localized in a single waveguide.This concept is experimentally implemented in a coupled silicon waveguide system at telecommunication wavelengths.Our work provides a new evolution strategy for chiral dynamics with superior performance,laying the foundation for the development of practical chiral-transmission devices.

关键词： chiral system symmetric

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A contrasting analysis of CO_(2)and n_(2)foam flood for enhanced oil recovery and geological storage of CO_(2)

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Petroleum Research 2024年第1期9卷 55-60页

作者： alireza Roozbahani Farshad soofivan ali sagban Hassoon al-Tameemi Hadi Abdollahi sogand saatchi Abdolhamid Ansari Petroleum Engineering Department Faculty of Chemical EngineeringTarbiat Modares UniversityTehranIran school of Chemical and Petroleum Engineering Shiraz UniversityShirazIran school of Chemical and Petroleum Engineering Shiraz BranchIslamic Azad UniversityShirazIran Department of Petroleum Engineering Science and Research BranchAzad UniversityTehranIran Department of Chemistry and Chemical Engineering Rasht BranchIslamic Azad UniversityRashtIran Department of Petroleum Engineering Lamerd BranchIslamic Azad UniversityLamerdIran

Foam flooding using CO_(2)has emerged as a promising method for both enhanced oil recovery(EOR)and the storage of CO_(2)in geological reservoirs.This study conducts a thorough analysis of the behavior of CO_(2)and n_(2)foams in bulk and porous media,utilizing bubble-scale analyses and foam flooding experiments.The study compares the foamability and longevity of CO_(2)and n_(2)foams,with findings indicating that n_(2)foam bubbles tend to be smaller and less varied in size than CO_(2)foam bubbles,leading to increased foam stability.Additionally,the study compares the half-lives of CO_(2)and n_(2)foams generated through sparging and winding methods,showing that n_(2)foam has half-lives 22 and 10 times greater than CO_(2)foam when produced using the sparging and winding methods,respectively.Furthermore,CO_(2)foam generated through the sparging method had a lower foaming volume than n_(2)foam due to CO_(2)'s solubility.In the foam flooding experiments,n_(2)foam proved more effective in recovering oil from porous media than CO_(2)foam,thus demonstrating the effectiveness of the foam injection procedure.These results offer valuable insights into the differing performance of n_(2)and CO_(2)foam floods for EOR and CO_(2)geological storage.

关键词： CO_(2)storage Foam flood Enhanced oil recovery n_(2)foam CO_(2)foam

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Towards defining soil quality of Mediterranean calcareous agricultural soils:Reference values and potential core indicator set

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International soil and Water Conservation Research 2024年第1期12卷 145-155页

作者： Germán A.Durán Daniel sacristán Edelweis Farrús Jaume Vadell Institut de Recerca i FormacióAgrària i Pesquera de les Illes Balears C/Eusebi Estada14507009PalmaSpain Plant Biology Department University of Valencia46100BurjassotValenciaSpain soil and Environmental Quality Department Centro de Investigaciones sobre Desertificación-CIDE(CSIC-Universitat de València-Generalitat Valenciana)Carretera Moncada-Náquera km 4.546113MoncadaValenciaSpain Universitat de les Illes Balears Cra.De Valldemossakm 7507122PalmaSpain

To avoid soil degradation,adapt to climate change and comply with the sustainable Development goals 2030(Un General Assembly),establishing the quality/fertility of the agricultural soils of the Mediterranean region and evaluate how these evolve with time is mandatory.This enables adequate management practices to be implemented.The Mediterranean calcareous region has received little attention in this sense,in spite its soil particularities.so,24 different representative calcareous agricultural soils of the Mediterranean region,including the main management strategies of agricultural soils(rainfed and irrigated),were sampled from the island of Mallorca;and their physical,chemical and biological properties determined.The values obtained for most of the soil characteristics allowed to establish an initial approach to the reference values for the type of calcareous agricultural soils considered,and to clearly distinguish the effect of rainfed or irrigation management practices on soils properties and dynamics.some enzyme activities were not stimulated by the irrigation conditions assayed or they were only in dry conditions,suggesting optimum enzyme activities could be obtained when alternating dry and humid soil conditions.soil organic carbon,calcium carbonate and active lime revealed of significant importance in the collection of soils.Finally,the results obtained clearly indicate the heterogeneity of the region and its implications on the different soil characteristics.Therefore,this study could serve as a starting point to adequately establish the quality(fertility)for Mediterranean calcareous agricultural soils and their reference values by conducting further research in this region and including more type of soils.

关键词： soil fertility Mediterranean agricultural soils Calcareous soils soil enzymes soil management

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Metal-modulated epitaxy of Mg-doped al_(0.80)In_(0.20)n-based layer for application as the electron blocking layer in deep ultraviolet light-emitting diodes

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Journal of semiconductors 2024年第5期45卷 80-89页

作者： Horacio Irán solís-Cisneros Carlos alberto Hernández-Gutiérrez Enrique Campos-González Máximo López-López Optomechatronics Group Tecnológico Nacional de México Campus Tuxtla Gutiérrezcarretera Panamericana 1080C.P.29050Tuxtla GutiérrezChiapasMéxico Departamento de Física Instituto Nacional de Investigaciones NuclearesCarretera México-Toluca s/nC.P.52750La Marquesa OcoyoacacMéxico Departamento de Física Centro de Investigación y estudios Avanzados del Instituto Politécnico NacionalAv.Instituto Politécnico Nacional 2508San Pedro ZacatencoGustavo A.Madero07360 Ciudad de MéxicoCDMXMéxico

This work reports the growth and characterization of p-alInn layers doped with Mg by plasma-assisted molecular beam epitaxy(PAMBE).alInn was grown with an al molar fraction of 0.80 by metal-modulated epitaxy(MME)with a thickness of 180 nm on si(111)substrates using aln as buffer layers.Low substrate temperatures were used to enhance the incorporation of indium atoms into the alloy without clustering,as confirmed by X-ray diffraction(XRD).Cathodoluminescence measurements revealed ultraviolet(UV)range emissions.Meanwhile,Hall effect measurements indicated a maximum hole mobility of 146 cm^(2)/(V∙s),corresponding to a free hole concentration of 1.23×10^(19)cm^(−3).The samples were analyzed by X-ray photoelectron spectroscopy(XPs)estimating the alloy composition and extracting the Fermi level by valence band analysis.Mg-doped alInn layers were studied for use as the electron-blocking layer(EBL)in LED structures.We varied the al composition in the EBL from 0.84 to 0.96 molar fraction to assess its theoretical effects on electroluminescence,carrier concentration,and electric field,using sILVACO Atlas.The results from this study highlight the importance and capability of producing high-quality Mg-doped p-alInn layers through PAMBE.Our simulations suggest that an al content of 0.86 is optimal for achieving desired outcomes in electroluminescence,carrier concentration,and electric field.

关键词： metal-modulated epitaxy alInn DUV-LED EBL simulation

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