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Regression analysis of squeezing-induced hybrid nanofluid flow in Darcy-Forchheimer porous medium

2018年

作者： (英)m.i.芬利

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Applied mathematics and mechanics(English Edition) 2025年第1期46卷 193-208页

作者： K.mUHAmmAD m.SARFRAZ Department of Humanities and Sciences School of Electrical Engineering and Computer Science National University of Sciences and Technology Department of mathematics Quaid-i-Azam University

This article presents a mathematical model addressing a scenario involving a hybrid nanofluid flow between two infinite parallel plates. One plate rem.i.s stationary, while the other moves downward at a squeezing velocity. The space between these plates contains a Darcy-Forchheimer porous medium. A mixture of water-based fluid with gold(Au) and silicon dioxide(Si O2) nanoparticles is formulated. in contrast to the conventional Fourier's heat flux equation, this study employs the Cattaneo-Christov heat flux equation. A uniform magnetic field is applied perpendicular to the flow direction, invoking magnetohydrodynamic(mHD) effects. Further, the model accounts for Joule heating, which is the heat generated when an electric current passes through the fluid. The problem.i. solved via NDSolve in mATHEmATiCA. Numerical and statistical analyses are conducted to provide insights into the behavior of the nanomaterials between the parallel plates with respect to the flow, energy transport, and skin *** findings of this study have potential applications in enhancing cooling systems and optimizing thermal management strategies. it is observed that the squeezing motion generates additional pressure gradients within the fluid, which enhances the flow rate but reduces the frictional drag. Consequently, the fluid is pushed more vigorously between the plates, increasing the flow velocity. As the fluid experiences higher flow rates due to the increased squeezing effect, it spends less time in the region between the plates. The thermal relaxation, however, abruptly changes the temperature, leading to a decrease in the temperature fluctuations.

关键词： convective boundary condition Darcy-Forchheimer medium hybrid nanofluid Joule heating magnetohydrodynamic (mHD) numerical solution squeezing flow regression analysis O361 O175.2

Vertical seismic absorber utilizing inertance and negative stiffness implemented with gas springs

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Earthquake Engineering and Engineering Vibration 2023年第1期22卷 225-241页

作者： Kalogerakou m Paradeisiotis A Antoniadis i Dynamics and Structures Laboratory School of Mechanical EngineeringNational Technical University of Athens15780 AthensGreece

A novel implementation of negative stiffness elements(NSEs)is proposed,utilizing industrial grade nitrogen gas springs as pre-stressed stiffness elements in a configuration with lever *** NSE is com.i.ed with an inerter to form a stiff dynamic absorber(SDA)for vertical seismic protection of structures with base *** SDA is optimized to minimize vertical accelerations while ensuring static structural integrity,excellent dam.i.g performance and containment of relative *** introduction of gas springs in place of conventional linear springs addresses important practical limitations through features of non-linearity and industrial grade *** proposed implementation is dimensioned for a 50-ton structure and evaluated numerically for 25 actual earthquake records,in comparison with a linear SDA model and an equivalent conventional damper(CD).individual and averaged results of acceleration and displacement time histories demonstrate vastly superior response compared to CD regarding induced accelerations for similar *** equivalency with the linear SDA model indicates the stability of the gas spring implementation while guaranteeing predictability,tested endurance,proper tolerances,and off-axis motion resistance without requiring additional guiding components,as opposed to conventional *** features render the proposed implementation a promising solution for the realization of NSEs in seismic protection.

关键词： negative stiffness gas springs vertical seismic protection KDamper inerter

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古代民主与现代民主

influence of inhomogeneity of grain-boundary region of nanocristalline materials on elastic properties

2017年

作者： (英)m. i.芬利

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广东有色金属学报 2005年第2期15卷 164-167页

作者： Stepanov Y.N. Alymov m.i. Baikov institute of metallurgy and materials Sciences RAS Moscow Russia

Experimental data indicate that Young’s modulus of materials decreases with the decreasing of the grain size. Obviously, the primary factor of this decrease is presence of grain-boundary region, which Young’s modulus other than in the bulk of crystallites. There is a set of various expressions for calculation of Young’s modulus of polycrystals, obtained under the assumption, that it is possible to consider a polycrystal as a composite consisting of a crystalline matrix and a intercrystalline layers (grain-boundary region). Calculations showed incorrectness of application of a majority of these expressions and a large error in the calculations for the nanocrystalline materials. By us, on the basis of the same assumptions, is also obtained analytical expression for calculating Young’s modulus of materials with grain size more than 30 nm, which is more exact, than all *** is necessary to consider under the calculation of effective Young’s modulus nanocrystalline materials with grain size of less than 30nm, that grain-boundary region itself is not uniform. it is reliably established, that the triple joints of grain boundaries have a structure and properties, different from the structure and the properties of grain boundaries, which these joints connect. For nanocrystalline materials the volume fraction of the triple joints in the grain-boundary region can reach 50% and even more. Therefore assumption was made, that the nanocrystalline materials should be represented as consisting of three phases (triple joints, grain boundary between the triple joints and crystallite). On the basis of this idea is obtained analytical expression for calculating of Young’s modulus nanocrystalline materials. The analysis shows that Young’s modulus calculated by this analytical expression coordinated with the theory and the experiment.

关键词：弹性体多相性结构性能铸锭工艺钢

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奴隶制

世界民族 1989年第3期 33-37页

作者： m.i.芬利傅举晋

一、奴隶制法学家佛罗伦提努斯曾将奴隶制界说为“一种据以使一个人处于另一个人支配之下的悖于天理的‘万民法’(ius gentium)制度”(《学说汇纂》1.5、4、1)。在非法学范围内,古人经常使用我们译之为“奴隶”一词(以及其词根绝非奴隶... 详细信息

一、奴隶制法学家佛罗伦提努斯曾将奴隶制界说为“一种据以使一个人处于另一个人支配之下的悖于天理的‘万民法’(ius gentium)制度”(《学说汇纂》1.5、4、1)。在非法学范围内,古人经常使用我们译之为“奴隶”一词(以及其词根绝非奴隶之意的词汇)的各种字眼,虽则并非出于粗心之故。其泛用程度远过于在法学范围中的使用。古希腊人的“奴隶”意义的词汇变化多端,他们在这方面的泛用尤为突出。他们往往将此等词汇泛用于诸如黑劳士之类的具有其他奴役关系的范畴中,而严格言之,黑劳士与其主人并无财产性关系。又如,在古典时代的希腊文中,“杜洛斯”(例如,与“安德拉波顿”比较)

关键词：奴隶制度奴隶主古典时代希腊文罗马帝国奴隶劳动泛用罗马世界法学家词汇变化

激光显微探针^(40)Ar/^(39)Ar定年系统

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科学通报 1994年第8期39卷 734-737页

作者：穆治国 m.i.卡尔宾柯北京大学地质学系北京100871

K-Ar定年中的^(40)Ar/^(39)Ar方法,使样品经快中子辐射,产生^(39)K(n,P)^(39)Ar反应,经适当校正后的^(40)Ar/^(39)Ar,用以下公式计算出年龄:T=1/λln[1+J×^(40)Ar/^(39)Ar]其中,λ为^(40)K的衰变常数(5.543×10^(-10)a^(-1)),J为转化系数,对^(39)K(n,p)^(39)Ar是通过与未知样品一同照射的已知年龄的样品计算求得的.激光显微探针^(40)Ar/^(39)Ar是在常规^(40)Ar/^(39)Ar方法上发展起来的,它与常规^(40)Ar/^(39)Ar相比,具有更多的优点:精度更高,用样量更少,由此解决了由于样品不均匀引起的问题.

关键词：脉冲激光显微探针定年氩同位素

Chlamydia trachomatis and sperm lipid peroxidation in infertile men

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Asian Journal of Andrology 2003年第1期5卷 47-49页

作者： A.Segnini m.i.Camejo F.Proverbio Centro de Biofisica y Bioquimica instituto Venezolano de investigaciones Cientlficas VenezuelaDepartamento de Biologia de Organismos Universidad Simon Bolivar Miranda VenezuelaCentro de Biofisica y Bioquimica Instituto Venezolano de Investigaciones Cientificas Venezuela.

Aim: To relate the presence of anti-Chlamydial trachomatis igA in semen with sperm lipid membrane peroxidation and changes in seminal parameters. methods: Semen samples of the male partners of 52 couples assessed for undiagnosed infertility were examined for the presence of igA antibody against C. trachomatis. The level of sperm membrane lipid peroxidation was estimated by determining the malondialdehyde (mDA) formation. Results: Sperm membrane of infertile males with positive igA antibodies against C. trachomatis showed a higher level of lipid peroxidation than that of infertile males with negative igA antibody (Pitive correlation (Pmatis antibody and the magnitude of sperm membrane lipid peroxidation. All the other tested semen parameters were found to be similar in the two groups. Conclusion: The activation of immune system by C. trachomatis may promote lipid peroxidation of the sperm membrane. This could be the way by which C. trachomatis affects fertility.

关键词： Chlamydia trachomatis lipid peroxidation spermatozoa male infertility

Anomalous reactivity of thermo-bioconvective nanofluid towards oxytactic microorganisms

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Applied mathematics and mechanics(English Edition) 2020年第5期41卷 711-724页

作者： S.i.ABDELSALAm m.m.BHATTi Basic Science Department Faculty of EngineeringThe British University in EgyptAl-Shorouk CityCairo 11837Egypt instituto de matemáticas-Juriquilla Universidad Nacional Autónoma de MéxicoBlvd.Juriquilla 3001Quer´etaro 76230M´exico College of mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590Shandong ProvinceChina

The peristaltic flow of a non-Newtonian nanofluid with swim.i.g oxytactic microorganisms through a space between two infinite coaxial conduits is investigated. A variable magnetic field is applied on the flow. The bioconvection flow and heat transfer in the porous annulus are formulated, and appropriate transformations are used, leading to the non-dimensionalized ruling partial differential equation model. The model is then solved by using the homotopy perturbation scheme. The effects of the germane parameters on the velocity profile, temperature distribution, concentration distribution, motile microorganism profile, oxytactic profile, pressure rise, and outer and inner tube friction forces for the blood clot and endoscopic effects are analyzed and presented *** is noticed that the pressure rise and friction forces attain smaller values for the endoscopic model than for the blood clot model. The present analysis is believed to aid applications constituting hemodynamic structures playing indispensable roles inside the human body since some blood clotting disorders, e.g., haemophilia, occur when some blood constituents on the artery wall get confined away from the wall joining the circulation system.

关键词： oxytactic swim.i.g microorganism swim.i.g variable magnetic field blood clotting endoscopy non-Newtonian fluid

Predicting maximum Lifespan Limits at mean menopausal Age

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Journal of mathematical Research with Applications 2025年第1期 133-142页

作者： m.SUmATHi S.ANTONY CARLA Department of mathematics N.M.S.S.Vellaichamy Nadar College Research Scholar (Part-time) Madurai Kamaraj University

The age at which a woman enters natural menopause has also been associated to death from any cause. menopause is a natural component of aging that happens between the ages of 45 and 55, with the average menopausal age being 51. Previous research has revealed the age at which women reach menopause, but there is no evidence to support the link between menopause and longevity. We made a study in assessing the limits of maximum lifespan at menopausal age in our previous article. in this paper, we aim to predict the maximum lifespan of women at mean menopausal age.

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