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Analytical study of pulsatile mixed electroosmotic and shear-driven flow in a microchannel with a slip-dependent zeta potential

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Applied Mathematics and Mechanics(English Edition) 2023年第6期44卷 1007-1022页

作者： D.BANERJEE S.pati p.BISWAS Department of Mathematics National Institute of Technology SilcharAssam 788010India Department of Mechanical Engineering National Institute of Technology SilcharAssam 788010India

The escalation of zeta potential by the influence of wall slip for the electrokinetically modulated flow through a microchannel motivates to consider the impact of hydrodynamic slippage upon the zeta or surface *** reported study undergoes an analytical exploration of the pulsatile electroosmosis and shear-actuated flow characteristics of a fluid with a Newtonian model through a microchannel with parallel plates by invoking the reliance of a zeta or surface potential on *** linearized poisson-Boltzmann and momentum equations are solved analytically to obtain the explicit expression of the electrical potential induced in the electrical double layer(EDL),the flow velocity field,and the volumetric flow rate for an extensive span of *** velocity field proximal to the microchannel wall is observed to enhance by an apparent zeta potential,and is further escalated for a thinner EDL and an oscillating electric field with a higher ***,near the core region of the microchannel,the flow velocity becomes invariant with the EDL *** result shows that the lower wall velocity contributes to the flow velocity along with the electroosmotic body force and the impact of the velocity of the wall underneath diminishes proximal to the upper ***,the volumetric flow rate increases when the thickness of the EDL decreases,owing to the influence of the wall ***,for thinner EDLs and medium and higher oscillating Reynolds numbers,the volumetric flow rate varies non-monotonously,correlative to the slip-free and slip cases.

关键词： apparent zeta potential electroosmotic flow Newtonian fluid pulsatile flow

Si/Si C-based DD hetero-structure IMpATTs as MM-wave power-source:a generalized large-signal analysis

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Journal of Semiconductors 2015年第6期36卷 58-63页

作者： Moumita Mukherjee p.R.Tripathy S.p.pati Centre for MM-wave Semiconductor Devices and Systems (CMSDS) DRDO Hi-Tech College of Engineering Former professor of Sambalpur University

A full-scale, self-consistent, non-linear, large-signal model of double-drift hetero-structure IMpATT diode with general doping profile is derived. This newly developed model, for the first time, has been used to analyze the large-signal characteristics of hexagonal SiC-based double-drift IMpATT diode. Considering the fabrication feasibility, the authors have studied the large-signal characteristics of Si/SiC-based hetero-structure devices. Under small-voltage modulation （~ 2%, i.e. small-signal conditions） results are in good agreement with calculations done using a linearised small-signal model. The large-signal values of the diode＇s negative conductance （5 × 106 S/m2）, susceptance （10.4 × 107 S/m2）, average breakdown voltage （207.6 V）, and power generating efficiency （15%, RF power： 25.0 W at 94 GHz） are obtained as a function of oscillation amplitude （50% of DC breakdown voltage） for a fixed average current density. The large-signal calculations exhibit power and efficiency saturation for large-signal （〉 50%） voltage modulation and thereafter decrease gradually with further increasing voltage-modulation. This generalized large-signal formulation is applicable for all types of IMpATT structures with distributed and narrow avalanche zones. The simulator is made more realistic by incorporating the space-charge effects, realistic field and temperature dependent material parameters in Si and SiC. The electric field snap-shots and the large-signal impedance and admittance of the diode with current excitation are expressed in closed loop form. This study will act as a guide for researchers to fabricate a high-power Si/SiC-based IMpATT for possible application in high-power MM-wave communication systems.

关键词： Si/SiC hetero-structure double drift diode full-scale large-signal modelling high-power parasiticeffects noise-analysis

potential of asymmetrical Si/Ge and Ge/Si based hetero-junction transit time devices over homo-junction counterparts for generation of high power

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Journal of Semiconductors 2011年第11期32卷 24-30页

作者： Moumita Mukherjee pravash R.Tripathy S.p.pati Centre of Millimeter-Wave Semiconductor Devices and Systems Institute of Radio Physics and ElectronicsUniversity of Calcutta puroshottam Institute of Engineering & Technology RourkelaOdishaIndiaSambalpur University AICTE Emeritus professor NISTPelur HillsBerhampurOdishaIndia

Static and dynamic properties of both complementary n-Ge/p-Si and p-Ge/n-Si hetero-junction DoubleDrift IMpATT diodes have been investigated by an advanced and realistic computer simulation technique, devel- oped by the authors, for operation in the Ka-, V- and W-band frequencies. The results are further compared with corresponding Si and Ge homo-junction devices. The study shows high values of device efficiency, such as 23%, 22% and 21.5%, for n-Ge/p-Si IMpATTs at the Ka, V and W bands, respectively. The peak device negative con- ductances for n-Si/p-Ge and n-Ge/p-Si hetero-junction devices found to be 50.7× 10^6 S/m^2 and 71.3× 106 S/m^2, which are -3-4 times better than their Si and Ge counterparts at the V-band. The computed values of RF powerdensity for n-Ge/p-Si hetero-junction IMpATTs are 1.0 ×10^9, 1.1 × 10^9 and 1.4× 10^9 W/m^2, respectively, for Ka-, V- and W-band operation, which can be observed to be the highest when compared with Si, Ge and n-Si/p-Ge devices. Both of the hetero-junctions, especially the n-Ge/p-Si hetero-junction diode, can thus become a superior RF-power generator over a wide range of frequencies. The present study will help the device engineers to choose a suitable material pair for the development of high-power MM-wave IMpATT for applications in the civil and defense-related arena.

关键词： admittance characteristics double drift diode high-power IMpATT high-efficiency MM-wave de- vice Si/Ge and Ge/Si material systems

Soft-sediment deformation structures in the Mesoproterozoic Kaimur Sandstone,Vindhyan Supergroup(Central India),and their seismotectonic implications

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Journal of palaeogeography 2023年第3期12卷 463-486页

作者： Jayanta Kumar pati Anuj Kumar Singh Department of Earth and planetary Sciences Faculty of ScienceUniversity of AllahabadPrayagraj211002India National Centre of Experimental Mineralogy and petrology 14 Chatham LinesUniversity of AllahabadPrayagraj211002India

The unequivocal identification of soft-sediment deformation structures(SSDS)is a significant attribute to constrain the effect of transient geological events in the spatio-temporal evolution of ancient sedimentary *** paper reports and discusses,for the first time,the occurrence of several cm-to dm-scale SSDS within sandstone successions of the Mesoproterozoic Kaimur Group(Vindhyan Supergroup),exposed at the Hanumandhara Hill of Chitrakoot-Satna border region,Madhya pradesh State,*** SSDS are confined to a deformed interval comprising seven individual sedimentary units of variable composition and texture,which are sandwiched between nearly horizontally undeformed sandstone *** SSDS consist of load structures(load casts,flame structures,pseudonodules and ball-and-pillow structures),contorted lamination,convolute lamination,boudins and pinch-and-swell structures,deformed cross-stratification,slump structures,clastic injections,fluid escape structures,and syn-sedimentary fractures/*** pre-sent study suggests that the formation of these SSDS is essentially related to a combination of processes(gravitational instability,liquefaction,fluidization,and fluid escape)predominantly induced by seismic *** addition,the restricted occurrence of fractures/faults in these deformed layers emphasizes the passage of seismically-induced Rayleigh *** the observed types of SSDS,their lateral homo-geneity and geographic distribution along with the geodynamic framework of the Vindhyan Basin,the whole area can be tentatively attributed to having experienced moderate-to high-magnitude(M≥5)*** present study combined with earlier reports of seismically-induced SSDS,from other regionally disposed formations belonging to the Lower(e.g.,Kajrahat Limestone,Chopan porcellanite,Koldaha Shale,Rohtas Limestone,and Glauconitic Sandstone of the Semri Group)and Upper(e.g.,Bhander Limestone of the Bhander Group)Vindhyan Supergroup,respectively,provi

关键词： Soft-sediment deformation structures SSDS Seismites Kaimur Group Vindhyan Basin Sand-stone Central India

A criterion based adaptive RSIC scheme in underwater communication

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Journal of Systems Engineering and Electronics 2021年第2期32卷 408-416页

作者： KHAN Md Rizwan DAS Bikramaditya pati Bibhuti Bhusan Department of Electronics and Telecommunication Engineering Veer Surendra Sai University of TechnologyBurla 768018India Department of Electrical Engineering Veer Surendra Sai University of TechnologyBurla 768018India

Multi-access interference(MAI)is the main source limiting the capacity and quality of the multiple-input multipleoutput orthogonal frequency division multiplexing(MIMO-OFDM)system which fulfills the demand of high-speed transmission rate and high quality of service for future underwater acoustic(UWA)***,multi-user detection(MUD)is needed at the receiver of the MIMO-OFDM system to suppress the effect of *** this research,MUD is achieved by using a criterion based adaptive recursive successive interference cancellation(RSIC)scheme at the receiver of a MIMO-OFDM system whose transceiver model in underwater communication is implemented by using the Bellhop simulation *** proposed scheme estimates and eliminates the MAI through user signal detection and subtraction from received signals at the receiver of the MIMO-OFDM system in underwater *** bit error rate(BER)performance of the proposed scheme is analyzed by using weight filtering and weight selection *** Matlab simulation,it is shown that the BER performance of the proposed scheme outperforms the conventional matched filter(MF)detector,the adaptive successive interference cancellation(SIC)scheme,and the adaptive RSIC scheme in the UWA network.

关键词： underwater acoustic(UWA) orthogonal frequency division multiplexing(OFDM) multi-user detection(MUD) multiaccess interference(MAI) recursive successive interference cancellation(RSIC)

people’s perspectives on heritage conservation and tourism development:a case study of Varanasi

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Built Heritage 2023年第3期7卷 34-45页

作者： Ananya pati Mujahid Husain Department of Geography Jamia Millia IslamiaNew Delhi110025India BIM plus plus project Consultants L.L.C Lynx TowerDubai Silicon Oasis341041DubaiUnited Arab Emirates

The conservation of heritage and heritage-based tourism are interrelated activities in which the development in one can lead to the growth of the other and vice *** recent years,people have become increasingly aware of the importance of heritage and the necessity of its ***’s knowledge and preservation of their roots and emotional attachments to traditions and places are beneficial for heritage conservation *** places are also considered a growth point for the tourism industry that supports small-and medium-scale industries as well as numerous cottage ***,with the development of tourism and related industries in heritage areas,the local community may face difficulties in performing their day-to-day activities in the *** many cases,local communities need to relocate and people must leave their residences due to the demand for tourism development.A case study of Varanasi City was conducted to obtain a detailed understanding of the impact of a recent tourism development programme(the Kashi Vishwanath Corridor project)and people’s perception of it through a review of newspaper *** was found that people had mixed reactions regarding the development *** immediate residents of the area who were directly affected by the process in terms of emotional,economic and social loss were opposed to the project,while tourists and other residents of the city were pleased with the development *** paper attempts to identify the changes that occurred in the area due to the project and to capture people’s perspectives regarding the corridor project of Varanasi.

关键词： Heritage Tourism Conservation Community Development

Effect of Zn Concentration on Microstructural,Optical,and Hyperfine properties of Nanocrystalline a-Fe_(2)O_(3)

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Acta Metallurgica Sinica(English Letters) 2014年第4期27卷 563-568页

作者： N.R.panda D.Sahu B.S.Acharya p.Nayak S.p.pati D.Das School of Basic Science Indian Institute of Technology BhubaneswarBhubaneswar 751013OdishaIndia School of physics Sambalpur UniversitySambalpur 768019OdishaIndia School of Chemistry Sambalpur UniversitySambalpur 768019OdishaIndia C.V.Raman College of Engineering Bhubaneswar 752054OdishaIndia Department of Electronic Engineering Tohoku UniversitySendai 980-8579Japan UGC-DAE CSR Sector IIILB-8Bidhan NagarKolkata 700098India

Efforts have been made to prepare nanocomposites of a-Fe2O3-ZnO by wet chemical route with varying concentrations of the *** microstructural properties of the samples are investigated by powder X-ray diffractometry（pXRD） and Transmission electron *** concentration of Zn ions（up to 20 at%） leads to the formation of nanocomposites of a-Fe2O3 and *** of ZnFe2O4 phase is detected by the substitution of higher concentration of Zn2？（30 at%） in the *** average size of the nanoparticles remains in the range of 22–27 nm as obtained from XRD *** results obtained from electron microscopic studies are also close to these *** measurement shows the excitonic peak of ZnO around 390 nm which gets strengthened with Zn *** spectra show the metal–oxygen band below 700 *** temperature Mssbauer studies of the samples show the transition of iron oxide form antiferromagnetic state to paramagnetic state with increasing concentration of Zn2？.Sharp quenching of hyperfine field with Zn concentration is observed as the Hintvalue reduced to zero from 51 T.

关键词： Iron oxide ZnO Electron microscopy Mssbauer study

Corrosion Behavior of Ψ and β Quasicrystalline Al–Cu–Fe Alloy

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Acta Metallurgica Sinica(English Letters) 2015年第9期28卷 1117-1122页

作者： Alvaro Torres Sergio Serna Cristobal patio Gerardo Rosas Facultad de Ciencias Químicas e Ingeniería p.A. Ing.Mecnica UAEM Av. Universidad 1001 Col. Chamilpa62210 Cuernavaca Mor. Mexico Centro de Investigación en Ingeniería y Ciencias Aplicadas UAEM Av. Universidad 1001 Col. Chamilpa62210 Cuernavaca Mor. Mexico Facultad de Ingeniería Universidad Autónoma del CarmenCampus Ⅲ Avenida Central S/N Esq. con Fracc. MundoMaya C.P. 24115 Ciudad del Carmen Campeche Mexico Instituto de Investigaciones Metalurgicas UMSNH Edificio U. Ciudad Universitaria Morelia Mich. 58000 Mexico

Two nanostructured A1-Cu-Fe alloys, A164Cu24Fe12 and A162.5Cu25.2Fe12.3, have been studied. Icosahedral quasicrystalline （ψ） A164CH24FeI2 and crystalline cubic （ β） ***25.2Fe12.3 cylindrical ingots were first produced using normal casting techniques. High-energy mechanical milling was then conducted to obtain β icosahedral and β intermetallic nanostructured powders. Electrochemical impedance spectroscopy, linear polarization resistance, and potentiodynamic polarization were used to investigate the electrochemical corrosion characteristics of the powders in solutions with different pH values. Current density （icorr）, polarization resistance （Rp）, and impedance modulus （121） were determined. The results showed that regardless of pH value, increasing the solution temperature enhanced the corrosion resistance of the both phases. However, the electrochemical behavior of the phase indicated that its stability depends on the submerged exposure time in neutral and alkaline environments. This behavior was related to the type of corrosion products present on the surfaces of the particles along with the diffusion and charge-transfer mechanisms of the corrosion process.

关键词： Nano-quasicrystalline AI-Cu-Fe alloy Mechanical alloying Corrosion

Cooperative Formation Control of Autonomous Underwater Vehicles:An Overview

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International Journal of Automation and computing 2016年第3期13卷 199-225页

作者： Bikramaditya Das Bidyadhar Subudhi Bibhuti Bhusan pati Department of Electrical Engineering Veer Surendra Sai University of Technology Department of Electrical Engineering National Institute of Technology

Formation control is a cooperative control concept in which multiple autonomous underwater mobile robots are deployed for a group motion and/or control mission. This paper presents a brief review on various cooperative search and formation control strategies for multiple autonomous underwater vehicles （AUV） based on literature reported till date. Various cooperative and formation control schemes for collecting huge amount of data based on formation regulation control and formation tracking control are discussed. To address the challenge of detecting AUV failure in the fleet, communication issues, collision and obstacle avoidance are also taken into attention. Stability analysis of the feasible formation is also presented. This paper may be intended to serve as a convenient reference for the further research on formation control of multiple underwater mobile robots.

关键词： Autonomous underwater vehicles (AUV) cooperative control formation control tracking control regulatory control.