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Performance evaluation of minimum quantity lubrication by vege-table oil in terms of cutting force,cutting zone temperature,tool wear,job dimension and surface finish in turning AISI-1060 steel

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第11期7卷 1790-1799页

作者： KHAn M.M.A. DHAr n.r. Department of Industrial and Production Engineering Shahajalal University of Science and Technology Sylhet 3114 Bangladesh Department of Industrial and Production Engineering Bangladesh University of Engineering and Technology (BUET) Dhaka Bangladesh

In all machining processes, tool wear is a natural phenomenon and it leads to tool failure. The growing demands for high productivity of machining need use of high cutting velocity and feed rate. Such machining inherently produces high cutting temperature, which not only reduces tool life but also impairs the product quality. Metal cutting fluid changes the performance of machining operations because of their lubrication, cooling and chip flushing functions, but the use of cutting fluid has become more problematic in terms of both employee health and environmental pollution. The minimization of cutting fluid also leads to economical benefits by way of saving lubricant costs and workpiece/tool/machine cleaning cycle time. The concept of minimum quantity lubrication (MQL) has been suggested since a decade ago as a means of addressing the issues of environmental intru- siveness and occupational hazards associated with the airborne cutting fluid particles on factory shop floors. This paper deals with experimental investigation on the role of MQL by vegetable oil on cutting temperature, tool wear, surface roughness and dimen- sional deviation in turning AISI-1060 steel at industrial speed-feed combinations by uncoated carbide insert. The encouraging results include significant reduction in tool wear rate, dimensional inaccuracy and surface roughness by MQL mainly through reduction in the cutting zone temperature and favorable change in the chip-tool and work-tool interaction.

关键词： Minimum quantity lubrication (MQL) Cutting force Chip-tool interface temperature Tool wear Surface roughness Dimensional deviation

Electroosmotic Flow of MHD Power Law Al_2O_3-PVC nanofluid in a Horizontal Channel: Couette-Poiseuille Flow Model

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Communications in Theoretical Physics 2018年第6期69卷 655-666页

作者： n.Shehzad A.Zeeshan r.Ellahi Department of Mathematics and Statistics FBAS IIUI

The current manuscript is reported about the eiectro-osmotic Couette-Poiseuille ftow of power law Al2O3- PVC nanofluid through a channel, in which upper wall is moving with constant velocity. The influences of magnetic field, mixed convection, joule heating, and viscous dissipation are also incorporated. The flow is generated because of constant pressure gradient in axial direction. The resulting flow problem is coupled nonlinear ordinary differential equations, which are at first modeled and then transform into dimensionless form through appropriate transformation. Analytical solution of the governing is carried out. The impact of modified Brinkman number, modified Magnetic field, electro-osmotic parameters on velocity and temperature are examined graphically. From the results, it is concluded that the Skin friction at moving isolated wail decreases with the increase of electro-osmotic parameter and reverse behavior for nusselt number at heated stationary wall occur.

关键词： Couette-Poiseuille flow power law nanofluid electro-osmotic flow MHD PVC Alumina

Aberrant adult neurogenesis in intractable epilepsy:can GABAergic progenitor transplantation normalize this process?

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neural regeneration research 2024年第7期19卷 1419-1420页

作者： Muhammad n.Arshad Janice r.naegele Department of Biology Wesleyan UniversityMiddletownCTUSA Department of neuroscience Tufts University School of MedicineBostonMAUSA

Temporal lobe epilepsy(TLE) is a common type of focal epilepsy characterized by seizure foci within the temporal *** surgical resection of the foci is an established and effective approach for controlling seizures,both temporal lobes cannot be removed,due to their prominent roles in learning and ***,seizures induce changes to the temporal lobes that contribute to hyperexcitability,including mossy fiber sprouting,astrogliosis.

关键词： epilepsy progenitor seizures

Thermal Efficiency for Each Zone of a Solar Pond

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Chinese Physics Letters 2011年第10期28卷 281-283页

作者： BEZİr CİCEK nalan ŞAHİnŞEnCAn Arzu Department of Physics Faculty of ScienceSuleyman Demirel UniversityTurkey Department of Mechanical Education Technical Education FacultySüleyman Demirel UniversityTurkey

A salt gradient solar pond with a surface area of 3.5×3.5 m^(2) and a depth of 2 m is *** collapsible covers are used to reduce thermal energy loss from the surface of the solar pond during the night and to increase the thermal efficiency of the pond solar energy harvesting during *** covers can be rotated between 0 and 180°by a controlled electric motor and has insulation and reflection *** thermal efficiency for each solar pond zone is investigated theoretically and experimentally.

关键词： properties insulation harvesting

Dynamics of lattice disorder in perovskite materials, polarization nanoclusters and ferroelectric domain wall structures

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npj Computational Materials 2023年第1期9卷 1137-1149页

作者： Jan Očenášek Ján Minár Jorge Alcalá new Technologies research Centre University of West Bohemia in Pilsen30614 PlzeňCzech Republic Department of Materials Science and Metallurgical Engineering InSupETSEIBUniversitat Politècnica de Catalunya08028 BarcelonaSpain

The nexus between classic ferroelectricity and the structure of perovskite materials hinges on the concept of lattice *** the ordered perovskites display short-range displacements of the central cations around their equilibrium points,the lattice disorder dynamically unfolds to generate a myriad of distorted rhombohedral lattices characterized by the hopping of the central cations across*** is discovered that the lattice disorder correlates with the emergence of minimum configuration energypathways for the central cations,resulting in spatially modulated ultrafast polarization nanocluster arrangements that are stabilized by the electric charge defects in the *** high-resolution phonon dispersion analyses encompassing molecular dynamics(MD)and density functional theory(DFT)simulations,we provide unequivocal evidence linking the hopping of central cations to the development of diffuse soft phonon modes observed throughout the phase transitions of the *** massive MD simulations,we unveil the impact of lattice disorder on the structures of domain walls at finite-temperature vis-à-vis collective activation and deactivation of***,our simulations demonstrate the development of hierarchical morphotropic phase boundary(MPB)nanostructures under the combined influence of externally applied pressure and stress relaxation,characterized by sudden emergence of zig-zagged monoclinic arrangements that involve dualshifts of the central *** findings have implications for tailoring MPBs in thin-film structures and for the light-induced mobilization of *** are finally uncovered to the exploration of lattice disorder through gradual shear strain application.

关键词： perovskite lattice ferroelectric

Experimental study on microstructural and corrosion behaviors of friction stir processed steel with CoCrFeCuTi HEA reinforcement and effect of annealing

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Science China Technological Sciences 2025年第1期 233-250页

作者： S.Aravind KrISHnA n.rADHIKA Alokesh PrAMAnIK n.JEYAPrAKASH Department of Mechanical Engineering Amrita School of EngineeringAmrita Vishwa Vidyapeetham School of Civil and Mechanical Engineering Curtin University School of Mechanical and Electrical Engineering China University of Mining and Technology

The ability to perform against extreme corrosion environments in stainless steel depreciates under challenging conditions in industrial applications. This can be resolved by employing surface modification techniques to modify the surface with the required characteristics. The present study investigates the outcomes of friction stir processing of SS304 with CoCrFeCuTi high entropy alloy(HEA) as reinforcement and the property enhancements post-annealing. The synthesized CoCrFeCuTi HEA exhibited irregular fragments with 17 μm mean particle size and body centred cubic(BCC) phase. The microstructure of the processed surface revealed ultra-refined grains with a uniform distribution of HEA filler. The microstructures of the samples annealed at 400℃, 550℃, 700℃ and 850℃ for 2 h also showed significant grain growth and grain refinements. The processed sample with HEA reinforcement annealed at 700℃ exhibited enhanced microhardness and tensile strength by 63% and 0.88 times than that of the processed sample with HEA pre-annealing. The subsequent electrochemical corrosion test displayed better corrosion resistance for the HEA-processed and annealed sample. Hot corrosion tests at 900℃ showcased excellent resistance for the HEA processed and annealed samples by 14.92%, 12.75%, and 14.83% against the samples pre-annealed under three different salt mixtures, and the corroded surface was analyzed.

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Characterization of Microstructure, Strength, and Toughness of Dissimilar Weldments of Inconel 625 and Duplex Stainless Steel SAF 2205

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Acta Metallurgica Sinica(English Letters) 2014年第6期27卷 1018-1030页

作者： r. Sridhar K. Devendranath ramkumar n. Arivazhagan School of Mechanical & Building Sciences VIT University Saraswathy Velu College of Engineering

The dissimilar combinations of Inconel 625 and duplex stainless steel SAF 2205 obtained from manual GTA welding process employing Er2209 and Erni CrMo-3 filler metals have been investigated. Formation of secondary phases at the HAZ of Inconel 625 and grain coarsening at the HAZ of SAF 2205 were witnessed while using these filler wires. The average hardness of Er2209 weldments was found to be greater than Erni CrMo-3 weld. Tensile fracture was observed at the weld zones for both the fillers. Impact test trials showed brittle mode of fracture on employing Er2209 filler and mixed（ductile–brittle） mode of fracture while using Erni CrMo-3 filler. Further optical microscopy and SEM/EDS analysis were carried out across the weldments to investigate the structure–property relationships.

关键词： Inconel 625 Duplex stainless steel SAF 2205 Dissimilar metal welding Microstructure Mechanical characterization

Impact of Clocking on the Aero-Thermodynamics of a Second Stator tested in a One and a Half Stage HP Turbine

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Journal of Thermal Science 2008年第2期17卷 97-110页

作者： n.Billiard G.Paniagua r.Dénos Turbomachinery and Propulsion Department von Karman Institute for Fluid Dynamics

This paper focuses on the experimental investigation of the time-averaged and time-accurate aero- thermodynamics of a second stator tested in a 1.5 stage high-pressure turbine. The effect of clocking on aerodynamic and heat transfer are investigated. Tests are performed under engine representative conditions in the VKI compression tube CT3. The test program includes four different clocking positions, i.e. relative pitch-wise positions between the fh-st and the second stator. Probes located upstream and downstream of the second stator provide the thermodynamic conditions of the flow field. On the second stator airfoil, measurements are taken around the blade profile at 15, 50 and 85% span with pressure sensors and thin-film gauges. Both time-averaged and time-resolved aspects of the flow field are addressed. regarding the time-averaged results, clocking effects are mainly observed within the leading edge region of the second stator, the largest effects being observed at 15% span. The surface static pressure distribution is changed locally, hence affecting the overall airfoil performance. For one clocking position, the thermal load of the airfoil is noticeably reduced. Pressure fluctuations are attributed to the passage of the up- stream transonic rotor and its associated pressure gradients. The pattern of these fluctuations changes noticeably as a function of docking. The time-resolved variations of heat flux and static pressure are analyzed together showing that the major effect is due to a potential interaction. The time-resolved pressure distribution integrated along the second stator surface yields the unsteady forces on the vane. The magnitude of the unsteady force is very dependent on the clocking position.

关键词： transonic flow turbines stator clocking forces heat transfer.

Biological nutrient removal by internal circulation upflow sludge blanket reactor after landfill leachate pretreatment

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Journal of Environmental Sciences 2013年第10期25卷 2130-2137页

作者： Alkhafaji r.Abood Jianguo Bao Zaidun n.Abudi State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences Thi Qar University Al-Mustansiryiah University College of Engineering

The removal of biological nutrient from mature landfill leachate with a high nitrogen load by an internal circulation upflow sludge blanket （ICUSB） reactor was studied. The reactor is a set of anaerobic-anoxic-aerobic （A^2/O） bioreactors, developed on the basis of an expended granular sludge blanket （EGSB）, granular sequencing batch reactor （GSBr） and intermittent cycle extended aeration system （ICEAS）. Leachate was subjected to stripping by agitation process and poly ferric sulfate coagulation as a pretreatment process, in order to reduce both ammonia toxicity to microorganisms and the organic contents. The reactor was operated under three different operating systems, consisting of recycling sludge with air （A^2/O）, recycling sludge without air （low oxygen） and a combination of both （A^2/O and low oxygen）. The lowest effluent nutrient levels were realised by the combined system of A^2/O and low oxygen, which resulted in effluent of chemical oxygen demand （COD）, nH3-n and biological oxygen demand （BOD5） concentrations of 98.20, 13.50 and 22.50 mg/L. The optimal operating conditions for the efficient removal of biological nutrient using the ICUSB reactor were examined to evaluate the influence of the parameters on its performance. The results showed that average removal efflciencies of COD and nH3- n of 96.49% and 99.39%, respectively were achieved under the condition of a hydraulic retention time of 12 hr, including 4 hr of pumping air into the reactor, with dissolved oxygen at an rate of 4 mg/L and an upflow velocity 2 m/hr. These combined processes were successfully employed and effectively decreased pollutant loading.

关键词： landfill leachate anaerobic-anoxic-aerobic (A^2/O) bioreactor biological nutrient removal combined treatment