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Cutting edge preparation of microdrills by shear thickening polishing for improved hole quality in electronic PCBs

Frontiers of Mechanical Engineering 2024年第2期19卷 99-107页

作者： Jiahuan WANG Mingfeng KE Jiepei LIAO Yu ZHOU saurav goel Jaya VERMA Xu WANG Weigang GUO Julong YUAN Binghai LYU College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310000China Ultra-precision Machining Center Key Laboratory of Special Purpose Equipment and Advanced Manufacturing TechnologyZhejiang University of TechnologyHangzhou 310000China school of Engineering London South Bank UniversityLondon SE10AAUK shenzhen Jinzhou Precision Technology Corporation Shenzhen 518116China Department of Mechanical Engineering University of Petroleum and Energy StudiesDehradun 248007India special Equipment Institute Hangzhou Vocational&Technical CollegeHangzhou 310018China

Printed circuit boards(PCBs)are representative composite materials,and their high-quality drilling machining remains a persistent challenge in the *** finishing of the cutting edge of a microdrill is crucial to drill performance in machining fine-quality holes with a prolonged tool *** miniature size involving submicron scale geometric dimensions,a complex flute shape,and low fracture toughness makes the cutting edge of microdrills susceptible to breakage and has been the primary limiting factor in edge preparation for *** this study,a newly developed cutting edge preparation method for microdrills was tested experimentally on electronic printed circuit *** proposed method,namely,shear thickening polishing,limited the cutting edge burrs and chipping on the cutting edge,and this in turn transformed the cutting edge’s radius from being sharp to ***,the edge–edge radius could be regulated by adjusting the processing *** drilling experiments were conducted to investigate the influence of different cutting edge radii on wear,hole position accuracy,nail head value,and hole wall *** proposed approach showed 20%enhancement in hole position accuracy,33%reduction in the nail head value,and 19%reduction in hole wall roughness compared with the original ***,a threshold is needed;without it,excessive shear thickening polishing will result in a blunt edge,which may accelerate the wear of the *** was identified as the primary factor that reduced hole *** study indicates that in printed circuit board machining,microdrills should effectively eliminate grinding defects and maintain the sharpness of the cutting edge as much as possible to obtain excellent drilling ***,shear thickening polishing is a promising method for cutting edge preparation of *** research and optimization can lead to additional improvements in microdrill performance and contribute to the conti

关键词： microdrill shear thickening polishing cutting edge preparation electronic printed circuit boards hole quality

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Parents’s knowledge and awareness about hepatitis B can influence the vaccination of their children

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World Journal of Virology 2024年第2期13卷 96-106页

作者： Nanda Chhavi Geetika srivastava Mariya Waseem Abhishek Yadav surender singh Rajani singh Amit goel Department of Paediatrics Era’s Lucknow Medical CollegeLucknow 226003Uttar PradeshIndia Medical Consultant National Disease Control ProgramNational Health MissionLucknow 226003Uttar PradeshIndia Department of Hepatology Sanjay Gandhi Postgraduate Institute of Medical SciencesLucknow 226014Uttar PradeshIndia

BACKGROUND Birth-dose(Hep-BD)followed by three additional doses(Hep-B3)of hepatitis B virus(HBV)vaccine are key to eliminating HBV by ***,Hep-BD and Hep-B3 coverage in our country is *** To studied the parent’s knowledge and awareness about HBV infection,its prevention,consequences and *** Parents of 6 months to 8 years old children were interviewed to assess their knowledge&awareness about hepatitis B,its transmission,prevention,illness caused by this,and *** close-ended questions were admini-stered,and responses were recorded as‘yes’,‘no’,or‘not sure’.HBV knowledge score was calculated based on the sum of correct *** correct response scored one point and incorrect,missing or‘not sure’responses received no *** data are presented as number(%)and numerical data are expressed as *** were compared using Chi2 tests and level of significance was kept as Ps(58.3%mothers)of 384 children(89.9%ages;82%age-appropriately vaccinated)were *** hundred and twenty-two(83.9%)children were Hep-B3 vaccinated.94.3%,87.5%,and 29.2%parents knew about polio,tetanus,and hepatitis B ***,41.2%,15.8%,and 23%parents knew about hepatitis B transmission,consequences of infection,and prevention *** 7.6%parents knew about three-dose schedule of hepatitis B *** 23%parents believed that vaccine could prevent HBV,15.7%knew that HBV affects *** of Hep-B3 vaccinated children were significantly more aware about HBV than the parents of unvaccinated children(Pstions).CONCLUsION The knowledge and awareness among the parents about hepatitis B is *** Increasing knowledge/awareness about HBV among parents may improve Hep-B3 vaccination coverage.

关键词： Hepatitis B Viral hepatitis Cirrhosis Hepatocellular carcinoma Hepatotropic viruses Transfusion transmitted infection Mother to child transmission

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Evaluation of Rainfall Tendency for the Twentieth Century over Indira sagar Region in Central India

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American Journal of Climate Change 2024年第1期13卷 47-68页

作者： Rituraj shukla Deepak Khare Ramesh P. Rudra Priti Tiwari Himanshu sharma Prasad Daggupati Pradeep goel school of Engineering University of Guelph Guelph Canada Department of Water Resources Development and Management Indian Institute of Technology Roorkee India Indira Gandhi Agricultural University Raipur India Department of Civil Engineering Institute of Infrastructure Technology Research and Management (IITRAM) Ahmedabad India

The study investigates long-term changes in annual and seasonal rainfall patterns in the Indira sagar Region of Madhya Pradesh, India, from 1901 to 2010. Agriculture sustainability, food supply, natural resource development, and hydropower system reliability in the region rely heavily on monsoon rainfall. Monthly rainfall data from three stations (East Nimar, Barwani, and West Nimar) were analyzed. Initially, the pre-whitening method was applied to eliminate serial correlation effects from the rainfall data series. subsequently, statistical trends in annual and seasonal rainfall were assessed using both parametric (student-t test) and non-parametric tests [Mann-Kendall, sen’s slope estimator, and Cumulative sum (CUsUM)]. The magnitude of the rainfall trend was determined using Theil-sen’s slope estimator. spatial analysis of the Mann-Kendall test on an annual basis revealed a statistically insignificant decreasing trend for Barwani and East Nimar and an increasing trend for West Nimar. On a seasonal basis, the monsoon season contributes a significant percentage (88.33%) to the total annual rainfall. The CUsUM test results indicated a shift change detection in annual rainfall data for Barwani in 1997, while shifts were observed in West and East Nimar stations in 1929. These findings offer valuable insights into regional rainfall behavior, aiding in the planning and management of water resources and ecological systems.

关键词： Precipitation Parametric Non-Parametric Tests Trend Analysis serial Correlations

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Experimental investigation into transient pressure pulses during pneumatic conveying of fine powders using shannon entropy

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Particuology 2016年第6期14卷 143-153页

作者： Amit goel Anu Mittal s.s. Mallick Atul sharma Department of Mechanical Engineering Thapar University Patiala Punjab 147004 India

This paper presents the results of an ongoing investigation into transient pressure pulses using shan- non entropy. Pressure fluctuations （produced by gas-solid two-phase flow during fluidized dense-phase conveying） are recorded by pressure transducers installed at strategic locations along a pipeline. This work validates previous work on identifying the flow mode from pressure signals （Mittal, Mallick, ＆ Wypych, 2014）. Two different powders, namely fly ash （median particle diameter 45 μm, particle den- sity 1950 kg/m3. loosely poured bulk density 950 kg/m3） and cement （median particle diameter 15 p,m, particle density 3060 kg/m3, loosely poured bulk density 1070 kg/m3）, are conveyed through different pipelines （51 mm I.D. × 70 m length and 63 mm I.D. × 24 m length）. The transient nature of pressure fluc- tuations （instead of steady-state behavior） is considered in investigating flow characteristics. shannon entropy is found to increase along straight pipe sections for both solids and both pipelines. However, shannon entropy decreases after a bend. A comparison of shannon entropy among different ranges of superficial air velocity reveals that high shannon entropy corresponds to very low velocities （i.e. 3-5 m/s） and very high velocities （i.e. 11-14 m/s） while low shannon entropy corresponds to mid-range velocities （i.e. 6-8 m/s）.

关键词： Transient pressure fluctuations Fluidized dense phase shannon entropy Flow pattern solid loading ratio superficial air velocity

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solar rooftop in India: Policies,challenges and outlook

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Green Energy & Environment 2016年第2期1卷 129-137页

作者： Malti goel science & Technological solutions for sustainable Energy Future Climate Change Research Institute

solar photovoltaic rooftop has emerged as a potential green technology to address climate change issues by reducing reliance on conventional fossil fuel based energy. With a strong commitment to increase the renewable sources based energy capacity to 175 GW by 2022, India has a target to install 100 GW of solar energy capacity. Of this 40 GW would be the share of grid connected solar PV rooftop. This paper examines global growth in solar energy, world's major rooftop installed capacity countries' policies and solar rooftop policy instruments in India. The current Indian goals, issues & challenges in achieving them and trends in further development are discussed.

关键词： solar energy India Rooftop PV Policies Outlook

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Phishing website prediction using base and ensemble classifier techniques with cross-validation

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Cybersecurity 2023年第1期6卷 17-39页

作者： Anjaneya Awasthi Noopur goel Department of Computer Applications VBS Purvanchal UniversityJaunpurUPIndia

Internet or public internetwork has become a vulnerable place nowadays as there are so many threats available for the novice or careless users because there exist many types of tools and techniques being used by notorious peo-ple on it to victimize people somehow and gain access to their precious and personal data resulting in sometimes ***,these victims suffer considerable losses in many instances due to their entrapment in such traps as hacking,cracking,data diddling,Trojan attacks,web jacking,salami attacks,and ***,despite the web users and the software and application developer's continuous effort to make and keep the IT infrastructure safe and secure using many techniques,including encryption,digital signatures,digital certificates,*** paper focuses on the problem of phishing to detect and predict phishing websites URLs,primary machine learning classifiers and new ensemble-based techniques are used on 2 distinct *** on a merged dataset,this study is conducted in 3 ***,they include classification using base classifiers,Ensemble classifiers,and then ensemble classifiers are tested with and without ***,their performance is analyzed,and the results are presented at last to help others use this study for their upcoming research.

关键词： Phishing Hacking Data diddling Machine learning Ensemble

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The hemispheric asymmetry of solar activity during the last century and the solar dynamo

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Chinese Journal of Astronomy and Astrophysics 2009年第1期9卷 115-126页

作者： Ashish goel Arnab Rai Choudhuri Department of Physics Indian Institute of Technology Department of Physics Indian Institute of Science

We believe the Babcock-Leighton process of poloidal field generation to be the main source of irregularity in the solar cycle. The random nature of this process may make the poloidal field in one hemisphere stronger than that in the other hemisphere at the end of a cycle. We expect this to induce an asymmetry in the next sunspot cycle. We look for evidence of this in the observational data and then model it theoretically with our dynamo code. since actual polar field measurements exist only from the 1970s, we use the polar faculae number data recorded by sheeley （1991, 2008） as a proxy of the polar field and estimate the hemispheric asymmetry of the polar field in different solar minima during the major part of the twentieth century. This asymmetry is found to have a reasonable correlation with the asymmetry of the next cycle. We then run our dynamo code by feeding information about this asymmetry at the successive minima and compare the results with observational data. We find that the theoretically computed asymmetries of different cycles compare favorably with the observational data, with the correlation coefficient being 0.73. Due to the coupling between the two hemispheres, any hemispheric asymmetry tends to get attenuated with time. The hemispheric asymmetry of a cycle either from observational data or from theoretical calculations statistically tends to be less than the asymmetry in the polar field （as inferred from the faculae data） in the preceding minimum. This reduction factor turns out to be 0.43 and 0.51 respectively in observational data and theoretical simulations.

关键词： sun activity -- sun magnetic fields -- sunspots

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Analytical modeling of subthreshold current and subthreshold swing of Gaussiandoped strained-si-on-insulator MOsFETs

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Journal of semiconductors 2014年第8期35卷 52-59页

作者： Gopal Rawat sanjay Kumar Ekta goel Mirgender Kumar sarvesh Dubey s.Jit Department of Electronics Engineering Indian Institute of Technology (BHU) Varanasi India Faculty of Electronics and Communication Engineering Shri Ramswaroop Memorial University Lucknow-Deva Road India

This paper presents the analytical modeling of subthreshold current and subthreshold swing of short- channel fully-depleted （FD） strained-si-on-insulator （ssOI） MOsFETs having vertical Gaussian-like doping pro- file in the channel. The subthreshold current and subthreshold swing have been derived using the parabolic approx- imation method. In addition to the effect of strain on silicon layer, various other device parameters such as channel length （L）, gate-oxide thickness （tox）, strained-si channel thickness （ts_si）, peak doping concentration （Np）, project range （Rp） and straggle （op） of the Gaussian profile have been considered while predicting the device characteris- tics. The present work may help to overcome the degradation in subthreshold characteristics with strain engineering. These subthreshold current and swing models provide valuable information for strained-si MOsFET design. Ac- curacy of the proposed models is verified using the commercially available ATLAsTM, a two-dimensional （2D） device simulator from sILVACO.

关键词： strained-si-on-insulator (ssOI) Poisson's solution short-channel-effects

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Quantification of hydration products in cementitious materials incorporating silica nanoparticles

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Frontiers of structural and Civil Engineering 2016年第2期10卷 162-167页

作者： L. P. sINGH A. goel s. K. BHATTACHARYYA G. MIsHRA CsIR- Central Building Research Institute Roorkee 247667 India Department of Chemistry Gurukul Kangri University Haridwar 249404 India

In the present work, silica nanoparticles （30-70nm） were supplemented into cement paste to study their influence on degree of hydration, porosity and formation of different type of calcium-silicate-hydrate （C-s-H） gel. As the hydration time proceeds, the degree of hydration reach to 76% in nano-modified cement paste whereas plain cement achieve up to 63% at 28 days. An influence of degree of hydration on the porosity was also determined. In plain cement paste, the capillary porosity at lhr is ~48%, whereas in silica nanoparticles added cement is -35 % only, it revealed that silica nanoparticles refines the pore structure due to accelerated hydration mechanism leading to denser microstructure. similarly, increasing gel porosity reveals the formation of more C-s-H gel. Furthermore, C-s-H gel of different CaJsi ratio in hydrated cement paste was quantified using X-ray diffractometer and thermogravimetry. The results show that in presence of silica nanoparticles, -24% C-s-H （Ca/si 〈 1.0） forms, leading to the formation ofpolymerised and compact C-s-H. In case of plain cement this type of C-s-H was completely absent at 28 days. These studies reveal that the hydration mechanism of the cement can be tuned with the incorporation of silica nanoparticles and thus, producing more durable cementitious materials.

关键词： degree of hydration porosity calcium-silicate-hydrate (C-s-H) silica nanoparticles

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Analysis of PC6 window function using fractional Fourier transform

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光电工程 2018年第6期45卷 60-68页

作者： Navdeep goel Jaspinder Kaur Electronics and Communication Engineering section Yadavindra College of Engineering Talwandi Sabo 151302 India

Fractional Fourier transform(FRFT)is a linear transform generalizing Fourier transform(FT)that plays an important role in the field of signal processing and *** contains an adjustable parameterα,which it rotates the signal in the time frequency plane and represents the signal in an intermediate domain between time and *** provides a measure about the angular distribution of signal’s energy in time frequency *** is a special case of FRFT when angleαis equal toπ/*** paper presents mathematical model for obtaining FRFT of PC6 window *** different parameters of this window function are also obtained with the help of simulation results.A comparison of window function parameters is presented using FT and *** comparison of this window function with Hanning window function is presented in terms of side Lobe Fall off Rate(sLFOR).For different values of FRFT order,PC6 window function shows variation in different *** by changing the FRFT order,the minimum stop band attenuation of the resulting window function can be controlled.

关键词：傅立叶变换信号函数数学模型

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