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Transient parameter analysis of pneumatic conveying of fine particles for predicting the change of mode of flow

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Particuology 2017年第3期15卷 82-88页

作者： shijo j.s. Niranjana Behera school of Mechanical & Building sciences VIT University Vellore Tamilnadu 632014 India

During the process of pneumatic conveying of fine particles, the flow mode may change from dense to dilute. In studying this mode change, we evaluate three parameters （Hurst exponent, shannon entropy, and phase-space attractor size） used in signal analysis. Experimental data of pneumatic conveying of fly ash at three locations along a 173-m-long pipeline were used for this analysis. Variations in magnitude of the Hurst exponent, shannon entropy, and size of the phase space attractor exhibit different trends in their variations for dense and dilute mode of flow. From these trends it is possible to predict the change from dense to dilute mode and the location along the length of the pipeline of this change in mode of flow.

关键词： Fluidized denseHurst exponent shannon entropy Phase space

Corrosion Inhibition of Mild steel in sulphuric Acid Using Luffa Aegyptiaca Leaves Extract

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Acta Metallurgica sinica(English Letters) 2014年第6期27卷 969-980页

作者： s. jyothi j. Ravichandran Post Graduate and Research Department of Chemistry Sri Ramakrishna Mission Vidyalaya College of Arts and Science

The corrosion inhibition of mild steel（Ms） in sulphuric acid using Luffa aegyptiaca（LA） leaves extract was investigated by weight loss studies, colorimetric measurements, potentiodynamic polarisation and electrochemical impedance spectroscopy. The adsorption of LA leaves extract was confirmed by Fourier transform infrared spectroscopy and optical profilometry. The inhibition efficiency increased with increasing concentration of the extract but decreased with rise in temperature and with the increase in acid strength. Furthermore, the inhibition efficiency synergistically increased on the addition of halide ions. Polarisation studies revealed that the LA extract acts as mixed- type inhibitor. Physical adsorption mechanism is proposed from the trend in inhibition efficiency with the change in temperature and from thermodynamic parameters. The adsorption of LA on Ms surface obeys Langmuir adsorption isotherm and follows the kinetic thermodynamic model of ElAwady at all temperatures studied.

关键词： Mild steel Adsorption Corrosion Thermodynamic properties FTIR

Operational Tau Approximation for the Fokker-Planck Equation

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Chinese Physics Letters 2012年第4期29卷 141-144页

作者： s.s.Dehcheshmeh s.Karimi Vanani j.s.Hafshejani Department of Mathematics Islamic Azad UniversityFarsan BranchFarsanIran

An extension of the operational Tau method (OTM) is used to solve the Fokker Planck equation arising in many physical *** extension yields an algebraic equivalent representation of the desired problem using arbitrary polynomial basis functions to decrease the size of the *** structure,properties and advantages of the OTM are presented,and some illustrative linear and nonlinear experiments are given to show the capability and efficiency of the proposed algorithm.

关键词： problems Approximation polynomial

VRs-DB:preserve confidentiality of users'data using encryption approach

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Digital Communications and Networks 2021年第1期7卷 62-71页

作者： j.s.Rauthan K.s.Vaisla Department of Computer and science Engineering Uttarakhand Technical UniversityDehradunUttarakhand248007India

We focus on security and privacy problems within a cloud database framework,exploiting the DataBase as a service(DBaas).In this framework,an information proprietor drives out its information to a cloud database professional *** Data-Owner(DO)encrypts the delicate information before transmission at the cloud database professional company end to offer information *** encryption ideas,nonetheless,are just halfway homomorphic as all of them intend to enable an explicit kind of calculation,which is accomplished on scrambled *** current plans can't be coordinated to solve genuine functional queries that include activities of various *** propose and evaluate a Verifiable Reliable secure-DataBase(VRs-DB)framework on shared tables along with many primary operations on scrambled information,which enables information interoperability,and permits an extensive possibility of structured Query Language(sQL)queries to be prepared by the service provider on the encoded *** show that our security and privacy idea is protected from two forms of threats and are fundamentally proficient.

关键词： Privacy security Cloud storage Encrypted query Cryptography sensitive data

A hybrid multi-degree-of-freedom vibration isolation platform for spacecrafts by the linear active disturbance rejection control

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Applied Mathematics and Mechanics(English Edition) 2020年第5期41卷 805-818页

作者： Weichao CHI s.j.MA j.Q.sUN College of science Northeastern UniversityShenyang 100819China Key Laboratory of Ministry of Education on safe Mining of Deep Metal Mines Northeastern UniversityShenyang 100819China Department of Mechanical Engineering School of EngineeringUniversity of CaliforniaMercedCA 95343U.S.A.

The hybrid vibration isolation, which takes advantages of both the passive and active approaches, has been an important solution for space missions. The objective of this paper is to design a vibration isolation platform for payloads on spacecrafts with the robust, wide bandwidth, and multi-degree-of-freedom(MDOF). The proposed solution is based on a parallel mechanism with six voice-coil motors(VCMs) as the actuators. The linear active disturbance resistance control(LADRC) algorithm is used for the active control. Numerical simulation results show that the vibration isolation platform performs effectively over a wide bandwidth, and the resonance introduced by the passive isolation is eliminated. The system robustness to the uncertainties of the structure is also verified by simulation.

关键词： hybrid vibration isolation stewart platform linear active disturbance rejection control(LADRC) stability robustness

Plasma density measurement and downstream etching of silicon and silicon oxide in Ar/NF3 mixture remote plasma source

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Plasma science and Technology 2019年第6期21卷 52-57页

作者： H j YEOM D H CHOI Y s LEE j H KIM D j sEONG s j YOU H C LEE Korea Research Institute of standards and science(KRIss) Daejeon 34113 Republic of Korea Department of Physics Chungnam National University Daejeon 34134 Republic of Korea

In this study,plasma density measurements were performed near the plume region of the remote plasma source (RPs) in Ar/NF3 gas mixtures using a microwave cutoff *** measured plasma density is in the range of 1010-1011 cm-3 in the discharge conditions with RPs powers of 2-4 kW and gas pressures of 0.87-4 *** plasma density decreased with increasing gas pressures and RPs powers under various Ar/NF3 mixing *** decrease in the plasma density measured at the fixed measurement position (plume region) can be understood by the reduction of the electron energy relaxation length with increases in the gas pressures and mixing ratio of NF3/(Ar/NF3).We also performed downstream etching of silicon and silicon oxide films in this *** etch rate of the silicon films significantly increases while the silicon oxide is slightly etched with the gas pressures and *** was also found that the etch rate strongly depends on the wafer position on the processing chamber electrode,and that the etch selectivity reached 96-131 in the discharge conditions of RF powers (3730-4180 W) and gas pressures (3.6-4 Torr).

关键词： remote plasma source electron density cutoff probe downstream etch

Flow of colloidal suspension and irreversibility analysis with aggregation kinematics of nanoparticles in a microchannel

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Applied Mathematics and Mechanics(English Edition) 2020年第11期41卷 1671-1684页

作者： s.sINDHU B.j.GIREEsHA Department of studies and Research in Mathematics Kuvempu UniversityShankaraghattaShivamogga 577451KarnatakaIndia

The current exploration focuses on the ethylene glycol(EG)based nanoliquid flow in a *** effectiveness of the internal heat source and linear radiation is reflected in the present *** estimation of suitable thermal conductivity model has affirmative impact on the convective heat transfer *** examination is conceded with the nanoparticle aggregation demonstrated by the Maxwell-Bruggeman and Krieger-Dougherty models which tackle the formation of *** models effectively describe the thermal conductivity and viscosity *** dimensionless mathematical expressions are solved numerically by the Runge Kutta Fehlberg approach.A higher thermal field is attained for the Bruggeman model due to the formation of thermal bridge.A second law analysis is carried out to predict the sources of irreversibility associated with the thermal *** is remarked that lesser entropy generation is obtained for the aggregation *** entropy generation rate declines with the slip flow and the thermal heat flux.A notable enhancement in the Bejan number is attained by increasing the Biot *** is established that the nanoparticle aggragation model exhibits a higher Bejan number in comparision with the usual flow model.

关键词： nanoparticle aggregation nanoliquid microchannel slip parameter heat flux

Role of ablation therapy in conjunction with surgical resection for neuroendocrine tumors involving the liver

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World journal of Gastrointestinal surgery 2024年第3期16卷 768-776页

作者： Alexander Ostapenko stephanie stroever Lud Eyasu Minha Kim Krist Aploks Xiang Da Dong Ramanathan seshadri Department of General surgery Danbury HospitalDanburyCT 06810United States Department of Research and Innovation Nuvance HealthDanburyCT 06810United States Division of surgical Oncology/Hepato-Pancreato-Biliary surgery Danbury HospitalDanburyCT 06810United States

BACKGROUND Resection of hepatic metastasis from neuroendocrine tumors(NETs)improves quality of life and prolongs 5-year *** can be utilized with surgery to achieve complete *** several studies report long-term out-comes for patients undergoing ablation,none have explored perioperative effects of ablation in patients with metastatic *** To determine if intra-operative ablation during hepatectomy increases risk of ad-verse outcomes such as surgical site infections(ssIs),bleeding,and bile *** A retrospective analysis of the hepatectomy National surgical Quality Impro-vement Program database from 2015-2019 was performed to determine the odds of ssIs,bile leaks,or bleeding in patients undergoing intraoperative ablation when compared to hepatectomy *** Of the 966 patients included in the study,298(30.9%)underwent ablation during *** were 78(11.7%)patients with ssIs in the hepatectomy alone group and 39(13.1%)patients with a ssIs in the hepatectomy with ablation *** leak occurred in 41(6.2%)and 14(4.8%)patients in the two groups,respec-tively;bleeding occurred in 117(17.5%)and 33(11.1%),*** con-trolling for confounding variables,ablation did not increase risk of ssI(P=0.63),bile leak(P=0.34)or bleeding(P=0.07)when compared to patients undergoing resection alone on multivariate *** Intraoperative ablation with hepatic resection for NETs is safe in the perioperative period without significant increased risk of infection,bleeding,or bile *** should utilize this modality when appropriate to a-chieve optimal disease control and outcomes.

关键词： Hepatectomy Neuroendocrine tumor Ablation Bile leaks Bleeding surgical site infections

Influence of Carrier Gas on Analysis of MgO Powders by Laser Ablation Inductively Coupled Plasma Mass spectrometry

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journal of Materials science & Technology 2009年第3期25卷 333-335页

作者： j.s. Lee Y.s. Lee C.j. Park H.s. Lee D.s. Lee Department of Chemistry Yonsei University Material Analysis Team Korea Testing Laboratory Korea Research Institute of standards and science school of Material science and Engineering Pusan National Univirsity

Laser ablation inductively coupled plasma mass spectrometry （LA-ICP-Ms） has been widely adopted for the direct multi-elemental analysis with high sensitivity. Especially analysis of fine ceramics by LA-ICP-Ms without time-consuming sample decomposition process has been one of the most expecting application field. small additive elements in MgO powders were analyzed by LA-ICP-Ms. For precise and accurate analysis influence of carrier gas （Ar or He） was presented by the signal intensities of ICP-Ms, relative standard deviation of signal intensities and ablated particle size distribution. Ablated particles were collected and analyzed by scanning electron microscopy （sEM） to investigate the particle size distribution, and the ablated sample surface was examined by camscope. In He gas atmosphere, the signal was more stable than in Ar gas atmosphere. The signal intensity was higher in Ar than in He. Examination of ablated particles and sample surface reveals that more particles were generated in Ar atmosphere and the distribution of particle size was larger.

关键词： Laser ablation MgO powders Carrier gas ICP-Ms