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prediction and analysis of process failures by ANN classification during wire-EdM of Inconel 718

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Advances in Manufacturing 2020年第4期8卷 519-536页

作者： Abhilash p.M. Chakradhar d. d.partment of Mechanical Engineering Indian Institute of Technology PalakkadPalakkadKeralaIndia

Wire breakages and spark absence are two typical machining failures that occur during wire electric discharge machining(wire-EdM),if appropriate parameter settings are not *** after several attempts to optimize the process,machining failures cannot be eliminated completely.A n offline classification model is presented herein to predict machining *** aim of the current study is to develop a multiclass classification model using an artificial neural network(ANN).The training dataset comprises 81 full factorial experiments with three levels of pulse-on time,pulse-off time,servo voltage,and wire feed rate as input *** classes are labeled as normal machining,spark absence,and wire *** model accuracy is tested by conducting 20 confirmation experiments,and the model is discovered to be 95%accurate in classifying the machining *** effects of process parameters on the process failures are discussed and analyzed.A microstructural analysis of the machined surface and worn wire surface is *** developed model proved to be an easy and fast solution for verifying and eliminating process failures.

关键词： Wire electric discharge machining(wire-EdM) process failure Spark absence Wire breakage Artificial neural network(ANN)classification Failure prediction

Nd-d.ped ZnO as a multifunctional nanomaterial

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Journal of Rare Earths 2012年第8期30卷 761-768页

作者： Surender Kumar p.d. Sahare d.partment of physics & Astrophysics University of Delhi

Chemically synthesised ZnO and Nd-d.ped ZnO nanoparticles were investigated for structural, optical, magnetic properties along with photocatalytic activity. Transmission electron microscopy measurement was performed on the und.ped and d.ped ZnO nanoparticles. Compared to the und.ped ZnO, Nd-d.ped ZnO nanoparticles showed enhanced.photoluminescent and ferromagnetic properties. The Nd- d.ped ZnO nanoparticles also showed improved.photocatalytic properties compared with the und.ped ZnO nanoparticles. Furthermore, the effect of UV light irradiation was studied with thermoluminescence （TL） and.photoluminescence （pL） measurement techniques. It was found that in case ofNd-d.ped ZnO nanoparticles TL intensity increased while the green emission in pL spectra decreased with UV-light irradiation. This was attributed to the production of more surface defects on UV irradiation on Nd-d.ping.

关键词： ZnO nanoparticles Nd-d.ping optical properties magnetic properties photocatalytic properties rare earths

Heterogeneity of mature oligodendrocytes in the central nervous system

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Neural Regeneration Research 2025年第5期20卷 1336-1349页

作者： Chao Weng Adam M.R.Groh Moein Yaqubi Qiao-Ling Cui Jo Anne Stratton G.R.Wayne Moore Jack p.Antel Neuroimmunology Unit Montreal Neurological Institute-HospitalDepartment of Neurology and NeurosurgeryMcGill UniversityMontrealQCCanada d.partment of Neurology Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina

Mature oligodendrocytes form myelin sheaths that are crucial for the insulation of axons and efficient signal transmission in the central nervous *** evidence has challenged the classical view of the functionally static mature oligodendrocyte and revealed a gamut of dynamic functions such as the ability to modulate neuronal circuitry and.provide metabolic support to *** the recognition of potential heterogeneity in mature oligodendrocyte function,a comprehensive summary of mature oligodendrocyte diversity is *** delve into early 20th-century studies by Robertson and Río-Hortega that laid the foundation for the modern identification of regional and morphological heterogeneity in mature ***,recent morphologic and functional studies call into question the long-assumed homogeneity of mature oligodendrocyte function through the identification of distinct subtypes with varying myelination ***,modern molecular investigations,employing techniques such as single cell/nucleus RNA sequencing,consistently unveil at least six mature oligodendrocyte subpopulations in the human central nervous system that are highly transcriptomically diverse and vary with central nervous system *** and disease related mature oligodendrocyte variation denotes the impact of pathological conditions such as multiple sclerosis,Alzheimer's disease,and.psychiatric ***,caution is warranted when subclassifying mature oligodendrocytes because of the simplification needed to make conclusions about cell identity from temporally confined *** studies leveraging advanced techniques like spatial transcriptomics and single-cell proteomics promise a more nuanced understanding of mature oligodendrocyte *** research avenues that precisely evaluate mature oligodendrocyte heterogeneity with care to understand the mitigating influence of species,sex,central nervous system region,age,and disease,

关键词： aging central nervous system diseases electron microscopy heterogeneity immunohistochemistry myelin sheath natural history neuroglia oligodendroglia single-cell gene expression analysis

performance Enhancement in dye-Sensitized Solar Cells with Composite Mixtures of TiO_2 Nanoparticles and TiO_2 Nanotubes

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Acta Metallurgica Sinica(English Letters) 2015年第3期28卷 354-361页

作者： d.Maheswari p.Venkatachalam d.partment of physics Bharathiar University d.partment of physics(ddE) Annamalai University

In the present investigation,a new composite nanostructured.photoanodes were prepared using TiO_2 nanotubes（TNTs） with TiO_2 nanoparticles（TNps）.TNps were synthesized by sol-gel method,and TNTs were prepared through alkali hydrothermal ***-sensitized solar cells（dSSCs） were fabricated with different photoanodes comprising of various ratios of TNTs ＋ TNps,synthetic indigo dye as photosensitizer,pMII（l-propyl-3-methylimidazolium iodide） as ionic liquid electrolyte and cobalt sulfide as counter *** structures and morphologies of TNps and TNTs were analyzed through X-ray diffractometer,transmission electron microscope and scanning electron *** results of the investigation showed that the dSSC-4 made with composite photoanode structure（TNTs/TNps）（90% of TNps ＋ 10% of TNTs） had improved.photocurrent efficiency（2.11%） than pure TNps（1.00%） and TNT film（0.78%）.Electrochemical impedance spectra revealed that the composite TNTs/TNps film-based dSSCs possessed the lowest charge-transfer resistances and longest electron ***,it could be concluded that the composite TNTs/TNps photoanode facilitates the charge transport rate and enhances the efficiencies of dSSCs.

关键词： TNps/TNTs composite mixtures Charge recombination Electron transport photovoltaic parameters EIS analysis

Isoscalar monopole strength in ^(100)Mo: an indicator for static triaxial 100 deformation in the ground state

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Chinese physics C 2023年第3期47卷 180-186页

作者：石跃 p.d.Stevenson d.partment of physics Harbin Institute of TechnologyHarbin 150001China d.partment of physics University of SurreyGuildfordGU27XHUnited Kindom

We perform deformation constraint symmetry-unrestricted three-dimensional time-d.pendent density functional theory(TddFT)calculations for the isoscalar monopole(ISM)mode in ^(100)*** moments are obtained as a function of time using time propagating states based on different deformations.A Fourier transform is then performed on the obtained response *** resulting ISM strength functions are compared with experimental *** the static potential-energy-surface(pES)calculations,the results using the SkM*and UNEdF1 energy-density functionals(EdFs)show spherical ground states and considerable softness in the triaxial *** pES obtained with the SLy4 EdF shows static triaxial *** TddFT results based on different deformations show that a quadrupole deformation(characterized byβ_(2))value of 0.25-0.30 gives a two-peak structure of the strength *** triaxial deformation(characterized by)from 0°to 30°results in the occurrence of an additional peak between the two,making the general shape of the strength functions closer to that of the *** microscopic TddFT analyses suggest that ^(100)Mo is triaxially deformed in the ground *** calculated isoscalar Q_(20) and Q_(22) strength functions show peaks at lower *** coupling of these two modes with the ISM mode is the reason for the three-peak/plateau structure in the strengths of ^(100)Mo.

关键词： nuclear structure nuclear vibration time-d.pendent density functional theory

problems with models assessing influences of tree size and inter-tree competitive processes on individual tree growth:a cautionary tale

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Journal of Forestry Research 2022年第2期33卷 565-577页

作者： p.W.West d.A.Ratkowsky Forest Research Centre Southern Cross UniversityLismoreNSWAustralia Tasmanian Institute of Agriculture University of TasmaniaHobartTASAustralia

In forest growing at any one site, the growth rate of an individual tree is determined.principally by its size, which reflects its metabolic capacity, and by competition from neighboring trees. Competitive effects of a tree may be proportional to its size;such competition is termed ‘sym-metric’ and generally involves competition below ground for nutrients and water from the soil. Competition may also be ‘asymmetric’, where its effects are disproportionate to the size of the tree;this generally involves competition above ground for sunlight, when larger trees shade smaller, but the reverse cannot occur. This work examines three model systems often seen as exemplars relating individual tree growth rates to tree size and both competitive processes. data of tree stem basal area growth rates in plots of even- aged, monoculture forest of blackbutt (Eucalyptus pilularis Smith) growing in sub-tropical eastern Australia were used to test these systems. It was found that none could distin-guish between size and competitive effects at any time in any one stand and, thus, allow quantification of the contribution of each to explaining tree growth rates. They were prevented from doing so both by collinearity between the terms used to describe each of the effects and technical problems involved in the use of nonlinear least-squares regression to fit the models to any one data set. It is concluded that quite new approaches need to be devised if the effects on tree growth of tree size and competitive processes are to be quantified and modelled successfully.

关键词： Symmetric competition Asymmetric competition Tree growth rate Growth modeling Nonlinear modeling

Atomic-scale simulations of material behaviors and tribology properties for BCC metal film

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Chinese physics B 2016年第1期25卷 412-418页

作者： H d Aristizabal p A parra p Lopez E Restrepo-parra pCM Computational Applications Universidad Nacional de Colombia-Sede ManizalesA.A.127ManizalesColombi Universidad Cató1ica de Manizales A.A.357ManizalesColombia

This work has two main purposes：（i） introducing the basic concepts of molecular dynamics analysis to material scientists and engineers, and （ii） providing a better understanding of instrumented indentation measurements, presenting an example of nanoindentation and scratch test simulations. To reach these purposes, three-dimensional molecular dynamics （Md） simulations of nanoindentation and scratch test technique were carried out for generic thin films that present BCC crystalline structures. Structures were oriented in the plane （100） and.placed on FCC diamond substrates. A pair wise potential was employed to simulate the interaction between atoms of each layer and a repulsive radial potential was used to represent a spherical tip indenting the sample. Mechanical properties of this generic material were obtained by varying the indentation d.pth and dissociation energy. The load-unload curves and coefficient of friction were found for each test; on the other hand, dissociation energy was varied showing a better mechanical response for films that present grater dissociation energy. Structural change evolution was observed.presenting vacancies and slips as the d.pth was varied.

关键词： molecular dynamics pair wise potential repulsive radial potential dissociation energy

Optical Studies of Fluorescent Mesoporous Silica Nanoparticles

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Journal of Materials Science & Technology 2013年第8期29卷 742-746页

作者： Surbhi Kumari p.d.Sahare d.partment of physics & Astrophysics University of DelhiNew Delhi 110007India

Spherically shaped mesoporous silica nanoparticles （MSNs） having honeycomb like porous structure were synthesized by sol-gel method. Transmission electron microscopy （TEM）, surface area measurement and X-ray diffractometry were used, revealing the hexagonal shaped.pores in MSNs. MSNs with surface area of 1104.47 m^2/g and large porosity of 2.8 nm in pore diameter and 0.87 cm^3/g in pore volume were synthesized. TEM images showed spherical nanoparticles of - 200-300 nm having honeycomb like pores. Stilbene 420 laser dye was incorporated in MSNs and.photoluminescence spectra of stilbene 420 in MSNs and in ethanol had been studied. Stilbene 420 laser dye showed high fluorescence intensity in the fluorescence spectra of MSNs than that of ethanol. The prolonged fluorescence lifetime decay of stilbene in MSNs and the increase in fluorescence intensity for stilbene 420 in MSNs would make these nanomaterials more useful for nanosensors and nanolasers application.

关键词： Mesoporous nano silica porosity Fluorescence Lifetime decay

Structural and Spectroscopic Characterizations of ZnO Quantum dots Annealed at different Temperatures

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Journal of Materials Science & Technology 2013年第11期29卷 1035-1039页

作者： Geeta Rani p.d.Sahare d.partment of physics and Astrophysics University of Delhi

Here, we report the synthesis and characterizations of sol-gel derived zinc oxide （ZnO） quantum dots （Qds） using zinc acetate dihydrate （Zn（CH3COO）2.2H20） and lithium hydroxide monohydrate （LiOH.H20） as raw material. The as-prepared ZnO Qds was annealed at different temperature （400, 700, and 900 ℃） and the structural, optical properties were investigated by X-ray diffraction （XRd）, high resolution transmission electron microscopy （HRTEM）, UV-Vis and.photoluminescence （pL） spectroscopy. The powder XRd.patterns of the obtained samples showed the formation of single-phase wurtzite structure and the morphological changes have been observed with increasing annealing temperature. In the absorption spectra, the optical band gap of nanocrystalline ZnO Qds decreased from 3.18 to 3.11 eV and the particle size increased with increasing temperature. In the pL spectra, a broad green emission peak related to defect levels in the visible range of the spectra have been recorded.

关键词： ZnO quantum dots photoluminescence UV-Vis spectroscopy