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International Journal of Biomathematics 2024年第5期17卷 229-256页

作者： Hiba el Asraoui m.hamed el Omari Ali el mfadel Khalid Hilal Laboratory of Applied mathematics Scientific Computing Sultan moulay Slimane University BP 523 Beni MellalMorocco

In this paper,we investigate the existence of solutions and analyze the large-time behavior for Gurtin-maccamy population model involving conformable fractional *** a preliminary step,we construct a generic structure of the solution associated with our proposed model by utilizing some basic properties and tools of conformable fractional *** establish the existence of a unique solution of the given model with the given initial *** last,by using the upper and lower solutions for the characteristic equation,we define the upper and lower boundaries for the obtained solution and describe the large-time behavior of the total population.

关键词： Age-dependent population conformable fractional operator upper and lower boundary of the solution dynamics of populations

Natural Convection of a Power-Law Nanofluid in a Square Cavity with a Vertical Fin

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Fluid Dynamics & materials Processing 2024年第9期20卷 2091-2108页

作者： Amira m’hadbi mohammed el Ganaoui Haïkel Ben hamed Amenallah Guizani Khalid Chtaibi LERmAB Department of Transition and Energy Efficiency ProfessionsIUT H Poincaréde LongwyUniversity of LorraineLongwy54400France LPT Center for Energy Research and Technologies(Borj Cedria2084)University of Tunis El ManarTunis1068Tunisia LTI Department of Mechanical Engineering and ProductionIUTUniversity of Picardie Jules-VerneAmiens80025France

The behavior of non-Newtonian power-law nanofluids under free convection heat transfer conditions in a cooled square enclosure equipped with a heated fin is investigated *** particular,the impact of nanofluids,composed of water and Al_(2)O_(3),TiO_(2),and Cu nanoparticles,on heat transfer enhancement is *** aim of this research is also to analyze the influence of different parameters,including the Rayleigh number(Ra=10^(4)-10^(6)),nanoparticle volume fraction(φ=0%-20%),non-Newtonian power-law indexes(n=0.6-1.4),and fin dimensions(Ar=0.3,0.5,and 0.7).Streamlines and isotherms are used to depict flow and related heat transfer *** indicate that thermal performance improves with increasing Rayleigh number,regardless of the nanoparticle type or nanofluid rheological *** suggests that the buoyancy force has a significant impact on heat transfer,particularly near the heat *** Nusselt number is more sensitive to variations in Cu nanoparticle volume fractions compared to Al₂O₃and TiO₂.moreover,the average Nusselt numbers for power-law nanofluids with n1)are greater(smaller)than for Newtonian fluids due to the decrease(increase)in viscosity with increasing(decreasing)shear rate,at the same values of Rayleigh number Ra owing to the amplification(attenuation)of the convective ***,the most substantial enhancement is observed with Cu-water shear-thinning nanofluid,where the Nusselt number increases by 136%when changing from Newtonian to shear thinning behavior and by 154.9%when adding 16%nanoparticle volume ***,an even larger increase of 57%in the average Nusselt number is obtained on increasing the fin length from 0.3 to 0.7.

关键词： Heat transfer nanofluid non-Newtonian fluid natural convection

Planning Target Volume margin in Linac-Based Stereotactic Radiosurgery for Brain metastases

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Planning Target Volume margin in Linac-Based Stereotactic Radiosurgery for Brain metastases

Journal of Cancer Therapy（癌症治疗） 2024年第7期 265页

作者： Hany S.Attallah Radwa m.hamed Khaled m.el-Shahat Aliaa mahmoud mahmoud Abdallah Ibraheem Haggag Emad moustafa Adel Yassin

来源：博看期刊评论

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Journal of Cancer Therapy 2024年第7期15卷 265-272页

作者： Hany S. Attallah Radwa m. hamed Khaled m. el-Shahat Aliaa mahmoud mahmoud Abdallah Ibraheem Haggag Emad moustafa Adel Yassin Department of Radiation Oncology International Medical Center (IMC) Cairo Egypt Department of Radiation Oncology Armed Forces Medical Collogue (AFCM) Cairo Egypt Department of medical Physics Al Azhar University Cairo Egypt Department of medical Physics International Medical Center (IMC) Cairo Egypt Department of medical Physics Department of Clinical Oncology Faculty of Medicine Zagazig University Zagazig Egypt

Background: The treatment of brain metastases with radiotherapy has shifted to the use of Stereotactic Radio-surgery (SRS). The technical issue of expanding the treatment volume around the Gross Tumor Volume (GTV) is a current debate. Radiotherapy centers use variable GTV-PTV margins, ranging from one to 2 mm. material and methods: We performed a dosimetric comparison in plans of twenty patients using three margins: PTV zero, PTV1, and PTV2. We also developed imaginary Peel volumes. These volumes are described as follows: Peel1 = PTV1 − GTV, Peel2 = PTV2 − GTV. Results: Our results showed that the mean PTV volume differed significantly across the different margins (p = 0.000). The V12 of the brain significantly varied as a function of PTV margin (p = 0.000). The target coverage and plan quality indices were not significantly different. The Peel volume dosimetric analysis showed that the mean dose was significantly higher in the nearby normal brain tissue: Peel1 (p = 0.022) and Peel 2 (p = 0.013). Conclusion: According to our dosimetric analysis, expanding the GTV into a PTV by 1 mm margin is more convenient than 2 mm.

关键词： SRS Brain metastases PTV

Temperature-jump tensile tests to induce optimized TRIP/TWIP effect in a metastable austenitic stainless steel

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International Journal of minerals,metallurgy and materials 2024年第9期31卷 2025-2036页

作者： mohammad Javad Sohrabi hamed mirzadeh Saeed Sadeghpour Abdol Reza Geranmayeh Reza mahmudi School of metallurgy and materials Engineering College of EngineeringUniversity of Tehran14395-515TehranIran Centre for Advanced Steels Research Materials and Mechanical EngineeringUniversity of Oulu90014 OuluFinland

In the present work,plastic deformation mechanisms were initially tailored by adjusting the deformation temperature in the range of 0 to 200℃ in AISI 304L austenitic stainless steel,aiming to optimize the strength-ductility *** was shown that the combined twinning-induced plasticity(TWIP)/transformation-induced plasticity(TRIP)effects and a wider strain range for the TRIP effect up to higher strains by adjusting the deformation temperature are good strategies to improve the strength-ductility synergy of this metastable stainless *** this regard,by consideration of the observed temperature-dependency of plastic deformation,the controlled sequence of TWIP and TRIP effects for archiving superior strength-ductility trade-off was intended by the pre-designed temperature jump tensile ***,the optimum tensile toughness of 846 mJ/m^(3) and total elongation to 133% were obtained by this strategy via exploiting the advantages of the TWIP effect at 100℃ and the TRIP effect at 25℃ at the later stages of the ***,a deformation-temperature-transformation(DTT)diagram was developed for this metastable ***,based on work-hardening analysis,it was found that the main phenomenon constraining further improvement in the ductility and strengthening was the yielding of the deformation-induced α′-martensite.

关键词： metastable stainless steels transformation-induced plasticity twinning-induced plasticity stacking fault energy mechanical properties

非等温时效对含银Al-mg-Si合金多层摩擦表面显微组织和腐蚀行为的影响

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Transactions of Nonferrous metals Society of China 2024年第2期34卷 408-422页

作者： hamed JAmSHIDI AVAL Department of materials Engineering Babol Noshirvani University of TechnologyBabol47148-71167Iran

研究非等温时效对添加不同银含量Al-mg-Si合金多层摩擦表面显微组织和腐蚀行为的影响。通过在耗材棒横截面上钻孔的方式添加4%、8%和13%(质量分数)的银。采用光学显微镜和电子显微镜研究涂层的显微组织,采用显微硬度和拉伸实验研究涂层... 详细信息

研究非等温时效对添加不同银含量Al-mg-Si合金多层摩擦表面显微组织和腐蚀行为的影响。通过在耗材棒横截面上钻孔的方式添加4%、8%和13%(质量分数)的银。采用光学显微镜和电子显微镜研究涂层的显微组织,采用显微硬度和拉伸实验研究涂层的力学性能,采用电化学测试研究样品的耐腐蚀性。结果表明,随着银添加量从4%(质量分数)增加到13%(质量分数),摩擦堆焊表面层的晶粒尺寸从(1.5±0.3)μm减小到(1.0±0.3)μm。铝基体中的溶质银能够加速Al-mg-Si合金的析出动力学。经非等温时效处理后,含银涂层的屈服强度和抗拉强度分别比不含银涂层高50.6%和43.5%。经非等温时效处理后,材料的腐蚀电流密度降低,含银和不含银样品的耐腐蚀性均提高,含银涂层的耐蚀性比无银镀层提高了96.5%。

关键词：非等温时效显微组织腐蚀行为 Al-mg-Si合金银添加剂多层摩擦堆焊

Actuator and sensor fault isolation in a class of nonlinear dynamical systems

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Journal of Automation and Intelligence 2024年第2期3卷 57-72页

作者： hamed Tirandaz Christodoulos Keliris marios m.Polycarpou KIOS Research Center for Intelligent Systems and Networks and the Department of Electrical and Computer EngineeringUniversity of CyprusNicosia 1678Cyprus

Fault isolation in dynamical systems is a challenging task due to modeling uncertainty and measurement noise,interactive effects of multiple faults and fault *** paper proposes a unified approach for isolation of multiple actuator or sensor faults in a class of nonlinear uncertain dynamical *** and sensor fault isolation are accomplished in two independent modules,that monitor the system and are able to isolate the potential faulty actuator(s)or sensor(s).For the sensor fault isolation(SFI)case,a module is designed which monitors the system and utilizes an adaptive isolation threshold on the output residuals computed via a nonlinear estimation scheme that allows the isolation of single/multiple faulty sensor(s).For the actuator fault isolation(AFI)case,a second module is designed,which utilizes a learning-based scheme for adaptive approximation of faulty actuator(s)and,based on a reasoning decision logic and suitably designed AFI thresholds,the faulty actuator(s)set can be *** effectiveness of the proposed fault isolation approach developed in this paper is demonstrated through a simulation example.

关键词： Actuator and sensor fault isolation Adaptive approximation Observer-based fault diagnosis Reasoning-based decision logic

Effect of Thermal Cycles on Creep Behavior of Bituminous Binder in Hot Regions

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Journal of Civil Engineering and Architecture 2024年第7期18卷 334-339页

作者： Bachir Glaoui mahdjoub Bendjima m.hamed merbouh martin Van de Ven Laboratoire de la Fiabilité des matériaux et Structures en Régions Sahariennes(FImAS) Université de Béchar B.P.417Béchar08000Algérie Laboratory of Road and Railway Engineering TU DelftP.O.Box 50482600 GA DelftThe Netherlands

This research is devoted to the study of creep behavior of asphalt binder in hot *** binder was subjected to thermal cycles due to the variation of temperature from day to *** cycles produce a heating-cooling *** evaluate the effect of climate change in laboratory,the DSR(dynamic shear rheometer)was used,and the results found with the nine samples were *** thermal cycles led to aging and therefore hardening of the ***,a rheological model was proposed that can represent the curves obtained experimentally,where it is able to describe the creep behavior of binders tested.A new model is proposed that correlates well with the experimental curves,which is called A+2 K.

关键词： Bitumen temperature heating/cooling DSR BBR model

Simple and sensitive method for the determination of trace amounts of thorium using a benzoquinone derivative

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Nuclear Science and Techniques 2019年第5期30卷 22-31页

作者： mostafa m.hamed Refaat F.Aglan Hot Laboratories and Waste management Center Atomic Energy Authority of Egypt

A novel simple, sensitive, rapid, direct, and spectrophotometry-based procedure was investigated to determine Th(IV) at trace amounts. The new method is based on Th(IV) chelation with 3,6-dichloro-2,5-dihydroxy-l,4-benzoquinone(DDBQ). The reagent reacts with Th(IV) in 0.1 m HCl to form an orange 1:2 complex. The stability constant value is 6.62×10~4 for the Th(IV)complex. The Th(IV)-DDBQ obtained shows one peak with a maximum at about 346 nm. The chelate forms immediately and the absorbance remains stable for over24 h. Beer's law was obeyed in the concentration range0–10 μg mL^(-1). The molar absorptivity and Sandell's sensitivity were 4.4×10~4 L mol^(-1)cm^(-1) and 0.0053 μg cm^(-2), respectively. Different analytical parameters were tested in detail. Interfering ion(cations and anions) effects were tested. methods for Th(IV) determination by second and third-derivative spectrophotometry were also introduced at about 344 and 341 nm, respectively. These two derivative orders offer the feature of sensitivity without the necessity for solvent extraction,heating, or pre-concentration steps. Finally, the methods were successfully utilized for Th(IV) determination in monazite, environmental water, and wastewater samples.

关键词： Th(IV) determination p-benzoquinone derivative Spectrophotometry

mineralogy and Geochemistry of Uraniferous Sandstones in Fault Zone,Wadi el Sahu Area,Southwestern Sinai,Egypt:Implications for Provenance,Weathering and Tectonic Setting

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Acta Geologica Sinica(English Edition) 2021年第3期95卷 830-845页

作者： Osama R.SALLAm.hamed ImIRA Amira m.el TOHAmY Abd elhadi AABBAS Nuclear materials Authority El-Maadi Cairo P.O.Box:530Egypt

Paleozoic rocks in the Wadi el Sahu area are affected by many major faults in different directions.A reverse fault trending NE-SW is exposed for about 300 m of its length as it cuts through the Abu Hamata and Adedia formations on the south side of Wadi el Sahu.A secondary ascending hydrothermal solution carrying heavy metals and radioactive minerals passed through the fault plain and the surrounding fractures,forming mineralized and radioactive *** mineralized zone thickness ranges from 60 cm to 200 cm along the fault *** rocks were analyzed radiometrically using a portable gamma-ray spectrometer,chemically by employing ICP-ES and ICP-mS,as well as mineralogically by both binocular and Environmental Scanning electron *** content was also determined by fire *** and U contents reached up to 2682 and 1216 ppm,*** investigations indicated the presence of uraninite,torbernite,autunite,sklodowskite,kasolite as uranium minerals,thorite as a thorium mineral,monazite,allanite and xenotime as REE-bearing minerals,zircon and columbite as accessory minerals,gold and nickel as precious and base metals,in addition to cassiterite,chalcopyrite,chalcocite and *** REE and U contents are attributed to the circulation of epigenetic U and REE-bearing hydrothermal solutions along the fault plain and its surrounding *** alteration processes could then be confirmed by the presence of the m-type tetrad effect in the REE-patterns of the ferruginous *** non-chondritic ratio of Nb/Ta,Zr/Hf and Y/Ho in the studied sandstone may be attributed to the tetrad *** Ce and Eu anomaly with unusual REE-patterns was represented by the presence of conjugated m-W tetrad effects,indicating either the dual effect of hydrothermal solutions or groundwater with *** results clarify that the tetrad-effects could be used as evidence for the environment of deposition and as an indication for gold minerali

关键词： uranium gold RREs tetrad effect