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Effect of machining parameters on edge-chipping during drilling of glass using grinding-aided electrochemical discharge machining （G-ECDM）

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Advances in Manufacturing 2018年第2期6卷 215-224页

作者： V. G. Ladeesh r. Manu Department of Mechanical Engineering National Institute of Technology Calicut Calicut Kerala 673601 India

The problem of eliminating edge-chipping at the entrance and exit of the hole while drilling brittle materials is still a challenging task in different industries. Grinding- aided electrochemical discharge machining （G-ECDM） is a promising technology for drilling advanced hard-to-ma- chine ceramics, glass, composites, and other brittle mate- rials. Edge-chipping at the entrance of the hole can be fully eliminated by optimizing the machining parameters of G-ECDM. However, edge-chipping at the exit of the hole is difficult to eliminate during the drilling of ceramics and glass. This investigation suggests some practical ways to reduce edge-chipping at the exit of the hole. For this pur- pose, a three-dimensional finite element model was developed, and a coupled field analysis was conducted to study the effect of four parameters, i.e., cutting depth, support length, applied voltage, and pulse-on time, on the maximum normal stress in the region where the edge- chipping initiates. The model is capable of predicting the edge-chipping thickness, and the results predicted by the model are in close agreement with the experiment results. This investigation recommends the use of a low voltage and low pulse-on time at the hole entrance and exit when applying G-ECDM to reduce the edge-chipping thickness. Moreover, the use of a full rigid support in the form of a base plate or sacrificial plate beneath the workpiece can postpone the initiation of chipping by providing support when the tool reaches the bottom layer of the workpiece, thereby reducing the edge-chipping thickness.

关键词： Grinding-aided electrochemical dischargemachining (G-ECDM) Finite element analysis Edge-chipping - Maximum normal stress

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The impact of gate misalignment on the analog performance of a dual-material double gate junctionless transistor

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journal of Semiconductors 2015年第9期36卷 47-53页

作者： S.Intekhab Amin r.K.Sarin Department of Electronics and Communication Engineering Dr.B.R.Ambedkar National Institute of Technology Jalandhar

The analog performance of gate misaligned dual material double gate junctionless transistor is demonstrated for the first time. The cases considered are where misalignment occurs towards source side and towards drain side. The analog performance parameters analyzed are： transconductance, output conductance, intrinsic gain and cut-off frequency. These figures of merits （FOMs） are compared with a dual material double gate inversion mode transistor under same gate misalignment condition. The impacts of different length of control gate （L 1） for a given gate length （L） are also studied and the optimum lengths La under misalignment condition to have better analog FOMs and high tolerance to misalignment are presented.

关键词： dual material double gate (DMDG) junctionless transistor inversion mode transistor gate misalign-ment analog FOMs

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Painlev Analysis,Lie Symmetries and Exact Solutions for Variable Coefficients Benjamin-Bona-Mahony-Burger (BBMB) Equation

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Communications in Theoretical Physics 2013年第8期60卷 175-182页

作者： Vikas Kumar r.K.Gupta ram jiwari School of Mathematics and Computer Applications Thapar UniversityPatiala147004PunjabIndia

In this paper, a variable-coefficient Benjarnin-Bona-Mahony-Burger （BBMB） equation arising as a math- ematical model of propagation of small-amplitude long waves in nonlinear dispersive media is investigated. The inte- grability of such an equation is studied with Painlevd analysis. The Lie symmetry method is performed for the BBMB equation and then similarity reductions and exact solutions are obtained based on the optimal system method. Further- more different types of solitary, periodic and kink waves can be seen with the change of variable coefficients.

关键词： BBMB equation Painleve analysis Lie symmetric analysis exact solutions

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A parametric study of the hydrodynamic roughness produced by a wall coating layer of heavy oil

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Petroleum Science 2017年第1期14卷 155-166页

作者： S. rushd r. S. Sanders Department of Chemical and Materials Engineering University of Alberta Edmonton AB Canada

In water-lubricated pipeline transportation of heavy oil and bitumen, a thin oil film typically coats the pipe wall. A detailed study of the hydrodynamic effects of this fouling layer is critical to the design and operation of oil-water pipelines, as it can increase the pipeline pressure loss （and pumping power requirements） by 15 times or more. In this study, a parametric investigation of the hydrodynamic effects caused by the wall coating of viscous oil was conducted. A custom-built rectangular flow cell was used. A validated CFD-based procedure was used to determine the hydrodynamic roughness from the measured pressure losses. A similar procedure was followed for a set of pipe loop tests. The effects of the thickness of the oil coating layer, the oil viscosity, and water flow rate on the hydrodynamic roughness were evaluated. Oil viscosities from 3 to 21300 Pa s were tested. The results show that the equivalent hydrodynamic roughness produced by a wall coating layer of viscous oil is dependent on the coating thickness but essentially independent of oil viscosity. A new correlation was developed using these data to predict the hydrodynamic roughness for flow conditions in which a viscous oil coating is produced on the pipe wall.

关键词： Pipeline transportation - Heavy oil Wallfouling Lubricated pipe flow CFD simulation

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Dissipation of pencycuron in rice plant

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journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2005年第8期6卷 756-758页

作者： PAL r. CHAKrABArTI K CHAKrABOrTY A CHOWDHUrY A Department of Agricultural Chemistry and Soil Science Calcutta UniversityCalcutta Pin-700 019 IndiaDepartment of Agricultural Chemistry and Soil Science Calcutta UniversityCalcutta Pin-700 019 IndiaDepartment of Agronomy Bidhan Chandra Krishi Viswavidyalaya Mohanpur West BengalPin-741 252 IndiaDepartment of Agricultural Chemistry and Soil Science Calcutta UniversityCalcutta Pin-700 019 India

Pencycuron is a non-systemic protective fungicide for controlling sheath blight of rice. However, information on the fate of pencycuron in rice plant is lacking. The degradation of pencycuron in waterlogged tropic rice field was *** was applied at recommended field dose (187.5 g a.i./ha) and double recommended dose to cropped plots for three consecutive years. Pencycuron was rapidly degraded in rice plant at all doses of pencycuron application with first order half-lives of 1.57～2.77 d. The study revealed that pencycuron is safe from the human and environmental contamination point of view.

关键词： Pencycuron Dissipation rice plant Sheath blight rhizoctonia solani

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Comparing growth and fine root distribution in monocultures and mixed plantations of hybrid poplar and spruce

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journal of Forestry research 2013年第2期24卷 247-254页

作者： Lahcen Benomar Annie Desrochers Guy r. Larocque Chaire industrielle CrSNG-UQAT-UQAM en aménagement forestier durable. Université du Québec en Abitibi-Témiscamingue Natural resources Canada Laurentian Forestry Centre

Disease prevention, biodiversity, productivity improvement and ecological considerations are all factors that contribute to increasing interest in mixed plantations. The objective of this study was to evaluate early growth and productivity of two hybrid poplar clones, P. balsamifera x trichocarpa （PBT） and P. maximowiczii x balsamifera （PMB）, one improved family of Norway spruce （Picea glauca （PA）） and one improved family of white spruce （Picea abies （PG）） growing under different spacings in monocultures and mixed plots. The plantations were established in 2003 in Abitibi-Témiscamingue, Quebec, Canada, in a split plot design with spacing as the whole plot factor （1 × 1 m, 3 × 3 m and 5 × 5 m） and mixture treatments as subplot factor （pure： PBT, PMB, PA and PG, and 1：1 mixture PBT：PA, PBT：PG, PMB：PA and PMB：PG）. results showed a beneficial effect of the hybrid poplar-spruce mixture on diameter growth for hybrid poplar clones, but not for the 5 × 5 m spacing because of the relatively young age of the plantations. Diameter growth of the spruces decreased in mixed plantings in the 1 × 1 m, while their height growth increased, resulting in similar aboveground biomass per tree across treatments. Because of the large size differences between spruces and poplars, aboveground biomass in the mixed plantings was generally less than that in pure poplar plots. Leaf nitrogen concentration for the two spruce families and hybrid poplar clone PMB was greater in mixed plots than in monocultures, while leaf nitrogen concentration of clone PBT was similar among mixture treatments. Because of its faster growth rate and greater soil resources demands, clone PMB was the only one showing an increase in leaf N with increased spacing between trees. Fine roots density was greater for both hybrid poplars than spruces. The vertical distribution of fine roots was insensitive to mixture treatment.

关键词： Picea glauca Populus balsamifera × trichocarpa P. maximowiczii × balsamifera mixed-species monoculture spacing fine root

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Photoluminescence from Silicon Nanocrystals in Encapsulating Materials

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journal of Materials Science & Technology 2013年第3期29卷 221-224页

作者： Z.Deng X.D.Pi j.j.Zhao D.Yang State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering Zhejiang University

Naturally oxidized freestanding silicon nanocrystals （Si NCs） are incorporated in commonly used encapsulating materials to explore the photoluminescent application of Si NCs in device structures such as solid-state lighting light-emitting diodes （LEDs） and solar cells. The quantum yield of Si NCs before the incorporation has reached about 45% at the excitation wavelength of 370 nm without any special surface modification. It is found that medium Ioadings, e.g., 5 wt% of Si NCs in encapsulating materials help to obtain high external quantum efficiency （EQE） of the mixtures of Si NCs and encapsulating materials. The curing of encapsulating materials significantly reduces EQE. Among all the encapsulating materials investigated in this work, silicone- OE6551 enables the highest EQE （21% at excitation wavelength λex = 370 nm） after curing. Based on current findings, we have discussed the continuous efforts to advance the photoluminescent application of Si NCs.

关键词： Photoluminescence Silicon nanocrystals Epoxy Silicone Quantum yield External quantum efficiency

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Elastodynamic analysis of anisotropic liquid-saturated porous medium due to mechanical sources

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Applied Mathematics and Mechanics(English Edition) 2007年第8期28卷 1049-1059页

作者： rajneesh Kumar Aseem Miglani N.r.Garg Department of Mathematics Kurukshetra University Kurukshetra-136 119India Department of Mathematics Guru jambheshwar University of Science and Technology Hisar-125 001India Department of Mathematics Maharshi Dayanand University Rohtak-124 001India

Elastodynamic analysis of an anisotropic liquid-saturated porous medium is made to study a deformation problem of a transversely isotropic liquid-saturated porous medium due to mechanical sources. Certain physical problems are of the nature, in which the deformation takes place only in one direction, e.g., the problem relating to deformed structures and columns. In soil mechanics, an assumption of only vertical subsidence is often invoked and this leads to the one dimensional model of poroelasticity. By consid- ering a model of one-dimensional deformation of the anisotropic liquid-saturated porous medium, variations in disturbances are observed with reference to time and distance. The distributions of displacements and stresses are affected due to the anisotropy of the medium, and also due to the type of sources causing the disturbances.

关键词： elastodynamic anisotropic liquid-saturated porous laplace transform,impulsive and concentrated sources

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Steganography-Based Transmission of Medical Images Over Unsecure Network for Telemedicine Applications

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Computers, Materials & Continua 2021年第9期68卷 4069-4085页

作者： romany F.Mansour Moheb r.Girgis Department of Mathematics Faculty of ScienceNew Valley UniversityEl-Kharga72511Egypt Department of Computer Science Faculty of ScienceMinia UniversityEl-MiniaEgypt

Steganography is one of the best techniques to hide secret *** steganography methods are available that use an image as a cover object,which is called image *** image steganography,the major features are the cover object quality and hiding data *** to poor image quality,attackers could easily hack the secret ***,the hidden data quantity should be improved,while keeping stego-image quality *** main aim of this study is combining several steganography techniques,for secure transmission of data without leakage and unauthorized *** this paper,a technique,which combines various steganographybased techniques,is proposed for secure transmission of secret *** the pre-processing step,resizing of cover image is performed with Pixel repetition Method(PrM).Then DES(Data Encryption Standard)algorithm is used to encrypt secret data before embedding it into cover *** encrypted data is then converted to hexadecimal *** is followed by embedding using Least Signification Bit(LSB)in order to hide secret data inside the cover ***,image de-noising using Convolutional Neural Network(CNN)is used to enhance the cover image with hidden encrypted *** Zerotrees of Wavelet Transform is used to compress the image in order to reduce its *** are conducted to evaluate the performance of proposed combined steganography technique and results indicate that the proposed technique outperforms all existing *** achieves better PSNr,and encryption/decryption times,than existing methods for medical and other types of images.

关键词： Steganography secure data transmission CNN encryption telemedicine

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用于BOF过程中动态终点控制的新取样方式和分析方法(英文)

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冶金分析 2006年第5期26卷 8-15页

作者： M.Wauters V.Tusset j.Knevels r.Meilland Thomas Bjrk A.Bengston Centrum of research in Metallurgy LiègeBelgium Heraeus-Electronite HouthalenBelgium Arcelor research SA Maizières les MetzFrance Korrosions-och Metallforskningsinstitutet StockholmSweden

为了实现缩短出钢时间从而提高碱性氧气转炉(BOF)的生产效率,与熔融分析控制相关的过程如停吹、提枪或倾炉都要避免。为了达到这个目标,建立了一种用于控制BOF过程的新方法。该方法采用了一种新颖的、可在吹炼过程中进行炉渣和钢同时收... 详细信息

为了实现缩短出钢时间从而提高碱性氧气转炉(BOF)的生产效率,与熔融分析控制相关的过程如停吹、提枪或倾炉都要避免。为了达到这个目标,建立了一种用于控制BOF过程的新方法。该方法采用了一种新颖的、可在吹炼过程中进行炉渣和钢同时收集的非均相取样器,并应用了为此专门设计的激光分析方法(LIBS)。使用该方法,目标是尽可能快地完成非均相取样器收集的炉渣和钢的分析(Fe,C,P,S等元素)。除了建立非均相临线取样方法外,还建立了一种基于LIBS的特殊分析程序,当分析过程中移动非均相样品时,用于识别来自炉渣和钢的激光光束。与冶金模型相结合,由非均相取样器得来的数据经过处理后,可动态评价精炼进展状况并规定矫正行为,从而实现安全直接的出钢。预期的效益在于减少再吹炼的比率、节省出钢时间(预计每炉能缩短23min),同时延长耐火炉衬的寿命,提高生产产量。

关键词：碱性氧气顶吹转炉动态终点控制取样 LIBS

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