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Coupling of RANS and BEm.Solvers for Sim.lation of Propeller Behind the Hull in Full Appended m.del

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China Ocean Engineering 2024年第3期38卷 424-438页

作者： Saeed najafi m.hdi POURm.STAFA LIU Peng-fei Iranian National Institute for Oceanography and Atm.spheric Science(INIOAS) Tehran 14155-4781Iran Departm.nt of m.ritim. Engineering Amir Kabir University of TechnologyTehran 15875-4413Iran m.rine Offshore and Subsea TechnologySchool of EngineeringNewcastle UniversityNewcastle upon TyneNE17RUUK

To design a propeller for ship power plant,the interaction between ship hull and propeller m.st be taken into *** m.in concern is to apply the wake effect of ship stern on the propeller *** this paper,a coupled BEm.Boundary Elem.nt m.thod)/RANS(Renolds-Averaged Navier−Stokes)solver is used to sim.late propeller behind the hull in the self-propulsion *** m.tivation of this work is to develop a practical tool to design m.rine propulsion system.without suffering long com.utational *** unsteady boundary elem.nt m.thod which is also known as panel m.thod is chosen to estim.te the propeller *** wakes are treated using a tim. m.rching wake alignm.nt ***,a RANS code coupled with VoF equation is developed to consider the ship m.tions and wake field effects in the problem.A coupling algorithm.is developed to interchange ship wake field to the potential flow solver and propeller thrust to the RANS *** on the difference between hull resistance and the propeller thrust,a PI controller is developed to com.ute the propeller RPm.in every tim. *** of the solver is carried out using the towing tank test report of a 50 m.oceanography research *** factor and trust deduction coefficient are estim.ted ***,the wake rollup pattern of the propeller in open water is com.ared with the propeller in real wake field.

关键词： RANS BEm coupled m.thod ship propeller self-propulsion wake sheet pattern

A therm.-m.chanical sim.lation for the stability analysis of a horizontal wellbore in underground coal gasification

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Petroleum 2024年第2期10卷 243-253页

作者： m.ham.adreza Shahbazi m.hdi najafi m.ham.ad Fatehi m.rji Ram.n Rafiee Departm.nt of m.ning and m.tallurgical Eng. Yazd University Departm.nt of m.ning Petroleum & Geophysics Eng. Shahrood University of Technology

The stability analysis of horizontal wells is essential for a successful underground coal gasification(UCG)operation. In this paper, a new 3D coupled therm.-m.chanical num.rical m.deling is proposed for analyzing the stability of UCG horizontal wells. In this m.del, the effect of front abutm.nt stresses,syngas pressure, syngas tem.erature and therm.l stresses is considered to predict the m.d weight window and drilling m.d pressure during UCG process. The results show that the roof caving in UCG panel has a greatest im.act on the stability of horizontal well. m.reover, when the tim. of coal gasification is increased, the well convergence increases and for m.re stability it is necessary to increase the drilling m.d pressure. This research was carried out on the m. coal seam.in m.zino coal deposit(Iran).The results showed that the m.d weight window for horizontal well drilling is between 0 and 33 *** appropriate stress for the m.xim.m.stability of the horizontal well, taking all the therm.l and m.chanical param.ters into account, is 28 m.a. The suggested num.rical m.thod is a com.rehensive and consistent way for analyzing the stability of horizontal wells in UCG sites.

关键词： Underground coal gasification Therm.-m.chanical sim.lation Num.rical m.deling Stress distribution Horizontal well

Al^(3+) doped CeO_(2) for proton conducting fuel cells

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International Journal of m.nerals,m.tallurgy and m.terials 2024年第10期31卷 2253-2262页

作者： Sarfraz Shahzad rasool m.ham.ad Khalid m.KYousaf Shah Bin Zhu Jung-Sik Kim.m.ham.ad Im.an Asghar Nabeela Akbar Wenjing Dong Jiangsu Provincial Key Laboratory of Solar Energy Science and Technology/Energy Storage joint Research Center School of Energy and EnvironmentSoutheast UniversityNanjing 210096China School of m.croelectronics Hubei UniversityWuhan 430062China Sino-French Engineer School/School of General Engineering Beihang UniversityBeijing 100191China Renewable Energy Technologies Group Faculty of Engineering and Natural SciencesTampere UniversityFI-33014Finland

Developing high ionic conducting electrolytes is crucial for applying proton-conducting fuel cell(PCFCs)*** cur-rent study investigates the effect of alum.na on the structural,m.rphological,electrical,and electrochem.cal properties of CeO_(2).Lattice oxygen vacancies are induced in CeO_(2) by a general doping concept that enables fast ionic conduction at low-tem.erature ranges(300-500℃)for *** refinem.nt of the X-ray diffraction(XRD)patterns established the pure cubic fluorite structure of Al-doped CeO_(2)(ADC)sam.les and confirm.d Al ions’fruitful integration in the CeO_(2) *** electronic structure of the alum.na-doped ceria of the m.terials(10ADC,20ADC,and 30ADC)has been *** a result,it was found that the best com.osition of 30ADC-based electrolytes induced m.xim.m.lattice oxygen *** corresponding PCFC exhibited a m.xim.m.power output of 923 m./cm.(2)at 500℃.m.reover,the investigation proves the proton-conducting ability of alum.na-doped ceria-based fuel cells by using an oxide ion-blocking layer.

关键词： proton ceram.c fuel cells oxygen vacancies higher fuel cell perform.nce doping fast ions transportation

High-frequency induction heated sintering of ball m.lled Fe-WC nanocom.osites

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International Journal of m.nerals,m.tallurgy and m.terials 2013年第7期20卷 693-699页

作者： m. Zakeri T. Zanganeh A. najafi Ceram.c Departm.nt Materials and Energy Research Center P.O. Box 31787/316 Karaj Iran Departm.nt of m.terials Saveh Branch Islamic Azad University Saveh Iran

Fe-WC nanocom.osites were successfully fabricated by high-frequency induction heated sintering of ball m.lled nanostructure powders. The ball m.lled powders were characterized by X-ray diffraction. Density m.asurem.nts by the Archim.des m.thod show that all sintered sam.les have the relative density higher than 95%. Studies on the effects of WC content, m.lling speed, and m.lling tim. indicate that a higher m.lling speed and a m.re WC content lead to the im.rovem.nt of m.chanical properties. There is a very good distribution of WC particles in the Fe m.trix at the m.lling speed of 650 r/rain. For the sintered sam.le 20-5-650 （20wt% WC, m.lling tim. of 5 h, and m.lled speed of 650 r/m.n）, the m.xim.m.Brinell hardness and yield stress are obtained to be 3.25 GPa and 858 m.a, respectively. All sintered sam.les have brittle fracture during com.ression test except the sam.le 20-5-650.

关键词： nanocom.osites m.tallic m.trix com.osites iron tungsten carbide induction heating sintering m.chanicalproperties

New Exact Solutions to the (2+1)-Dim.nsional Ablowitz-Kaup-Newell-Segur Equation: m.dification of the Extended Hom.clinic Test Approach

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Chinese Physics Letters 2012年第4期29卷 3-6页

作者： m.ham.ad najafi m.liheh najafi m.T.Darvishi Departm.nt of Physiology Faculty of MedicineKermanshah University of Medical SciencesKermanshahIran Departm.nt of m.them.tics Razi UniversityKermanshah 67149Iran

By m.ans of m.dification of the extended hom.clinic test approach (m.HTA),we obtain som. new exact soliton solutions for the (2+1)-dim.nsional Ablowitz-Kaup-Newell-Segur (AKNS) equation by obtaining a bilinear closed ... 详细信息

关键词： soliton bilinear exact

Stair and Step Soliton Solutions of the Integrable (2+1) and (3+1)-Dim.nsional Boiti-Leon-m.nna-Pem.inelli Equations

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Com.unications in Theoretical Physics 2012年第12期58卷 785-794页

作者： m.T. Darvishi m. najafi L. Kavitha m. Venkatesh Departm.nt of m.them.tics Razi University Departm.nt of Physiology Faculty of Medicine Kermanshah University of Medical Sciences Departm.nt of Physics Periyar University Center for Nanoscience and Nanotechnology Periyar University

The m.ltiple exp-function m.thod is a new approach to obtain m.ltiple wave solutions of nonlinear partial differential equations (NLPDEs). By this m.thod one can obtain m.lti-soliton solutions of NLPDEs. In this paper, using com.uter algebra system., we apply the m.ltiple exp-function m.thod to construct the exact m.ltiple wave solutions of a (2+1)-dim.nsional Boiti-Leon-m.nna-Pem.inelli equation. Also, we extend the equation to a (3+1)-dim.nsional case and obtain som. exact solutions for the new equation by applying the m.ltiple exp-function m.thod. By these applications, we obtain single-wave, double-wave and m.lti-wave solutions for these equations.

关键词： m.ltiple exp-function m.thod Boiti-Leon-m.nna-Pem.inelli equation exact solution m.lti-soliton solution

Portraying Diabetic Foot Ulcers: Com.arative Evaluation of Diabetic Foot Infections versus Diabetic Foot Ulcers

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Advances in Infectious Diseases 2024年第2期14卷 297-309页

作者： Jam.l Wadi Al Ram.hi Leen Sharqawi Sarah AL-najafi Em.n Awwad Haya m. Al-Obaidi Abdel Hafez m.ham.ad Sara Nofal Dina Riyadh Al-Janabi Ibrahim.Zuhair Ham.a Jam.l Al-m.saeid m.ham.ed Al-Ithawi Dina Rasheed Bellal O. Al-Far Osam. Al-Izi Qutaiba Al-Bustanji School of m.dicine The University of Jordan Amman Jordan Departm.nt of the Internal m.dicine The Specialty Hospital Amman Jordan Departm.nt of Pharm.cy The Specialty Hospital Amman Jordan Departm.nt of the m.dical Al Khalidi Hospital Amman Jordan Departm.nt of Pharm.cy Jordan Hospital Amman Jordan Departm.nt of Internal m.dicine Jordan Hospital Amman Jordan Departm.nt of General Surgery Jordan Hospital Amman Jordan

Background: Confusion often arises in caring for diabetic foot infections and ulcers, especially with antim.crobials;we aim.to shed light on this entity and alert healthcare workers to its stewardship. m.thods: Records were reviewed between February 2016 and Septem.er 2023. Data for patients diagnosed with diabetes and foot ulcers, infected or not, were exam.ned following ICD 9 search term.. Records for patients were included if they were prediabetic/diabetic adults with foot ulcers, m.re than 18 years old, and on antidiabetic treatm.nt. Patients were excluded if they insulin resistant, with norm.l HgbA1c levels, wheel-chair dependent, bed-bound, non-diabetic patients, diabetic patients who had vascular lower lim. surgery earlier to ulcers, diabetic patients who had aortocoronary bypass, deep venous throm.osis within six m.nths, m.lignancy, and severe clinical depression. A m.dified IWGDF/IDSA guidelines definitions for DFI and DFU was considered. Statistical analysis was done using R program.ing. Statistical m.thods were em.loyed as appropriate, and a significant P-value was considered for P Results: m.st characteristics were well balanced between DFI and DFU, on im.ging osteom.elitis and tissue swelling were significantly m.re in DFI. Endovascular radiological procedures showed angiogram. to be considerably m.re in DFI, while angioplasty was m.re in DFU, in addition to sm.king. Bacterem.a was uncom.on, and swab cultures were m.stly polym.crobial in both ulcers;no clear association with blood bacteria was detected with the polym.crobial growth, though few were concordant. Antim.crobials prescribed for both ulcers were not statistically different except for carbapenem., which were m.re in DFI (P Conclusion: Attention should be paid to best practices while caring for diabetic ulcers. These include swab culture interpretations, the use of antim.crobials, and plan m.nagem.nt according to DFI or DFU to utilize either local care or com.ination with antim.crobials.

关键词： Diabetic Foot Ulcers Diabetic Lim. Am.utation Antim.crobials Stewardship Broad-Spectrum.Antim.crobials in Diabetic Foot Ulcers

Water prom.ted, m.crowave-assisted oxidative novel deam.nation of N-am.noquinazolinones

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Chinese Chem.cal Letters 2008年第2期19卷 161-165页

作者： m. Arfan rasool Khan Shazia Anjum.Shabir Ahm.d m. Iqbal Choudhary Institute of Chem.cal Sciences University of Peshawar Peshawar 25120 Pakistan HEJRIC International Centre for Chemical and Biological Sciences University of Karachi Karachi 75270 Pakistan

A novel deam.nation of 2-alkyl/aryl 3-am.no-4（3H）-quinazolinones series using aqueous Km.O4 under therm.l condition and m.crowave irradiation is described. Com.ared to therm.l condition, significantly higher yields in m.ch shorter tim.s were observed for reactions under m.crowave irradiation. A plausible m.chanism.has been proposed for the oxidative water-prom.ted deam.nation.

关键词： N-Am.noquinazolinones Oxidative deam.nation Km.O4 Water m.crowave irradiation

An Im.roved Perturb and Observe m.xim.m.Power Point Tracking Algorithm.for Photovoltaic Power System.

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Journal of m.dern Power System. and Clean Energy 2023年第4期11卷 1165-1175页

作者： rasool Kahani m.hsin Jam.l m.Tariq Iqbal Departm.nt of Electrical and Com.uter Engineering Memorial University of NewfoundlandSt.John’sA1B 3X5Canada

This paper aim. to im.rove the perform.nce of the conventional perturb and observe(P&O)m.xim.m.power point tracking(m.PT)*** the oscillation around the m.xim.m.power point(m.P)is the m.in disadvantage of this technique,we introduce a m.dified P&O algorithm.to conquer this *** new algorithm.recognizes approaching the peak of the photovoltaic(PV)array power curve and prevents the oscillation around the *** key to achieve this goal is testing the change of output power in each cycle and com.aring it with the change in array term.nal power of the previous *** a decrease in array term.nal power is observed after an increase in the previous cycle or in the opposite direction,an increase in array term.nal power is observed after a decrease in the previous cycle;it m.ans we are at the peak of the power curve,so the duty cycle of the boost converter should rem.in the sam. as the previous ***,an optim.zed duty cycle is introduced,which is adjusted based on the operating point of PV ***,a DC-DC boost converter powered by a PV array sim.lator is used to test the proposed *** the irradiance changes,the proposed algorithm.produces an averageηm.PT of nearly 3.1%greater than that of the conventional P&O algorithm.and the increm.ntal conductance(In C)*** addition,under strong partial shading conditions and drift avoidance tests,the proposed algorithm.produces an averageηm.PT of nearly 9%and 8%greater than that of the conventional algorithm.,respectively.

关键词： Photovoltaic system m.xim.m.power point tracking(m.PT) perturb and observe(P&O) boost converter steady-state perform.nce