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Experimental verification of bridge seismic damage states quantified by calibrating analytical models with empirical field data

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Earthquake Engineering and Engineering Vibration 2008年第4期7卷 383-393页

作者： Swagata banerjee Masanobu Shinozuka Department of Civil and Environmental Engineering University of California

Bridges are one of the most vulnerable components of a highway transportation network system subjected to earthquake ground motions. Prediction of resilience and sustainability of bridge performance in a probabilistic manner provides valuable information for pre-event system upgrading and post-event functional recovery of the network. The current study integrates bridge seismic damageability information obtained through empirical, analytical and experimental procedures and quantifies threshold limits of bridge damage states consistent with the physical damage description given in HAZUS. Experimental data from a large-scale shaking table test are utilized for this purpose. This experiment was conducted at the University of Nevada, Reno, where a research team from the University of California, Irvine, participated. Observed experimental damage data are processed to identify and quantify bridge damage states in terms of rotational ductility at bridge column ends. In parallel, a mechanistic model for fragility curves is developed in such a way that the model can be calibrated against empirical fragility curves that have been constructed from damage data obtained during the 1994 Northridge earthquake. This calibration quantifies threshold values of bridge damage states and makes the analytical study consistent with damage data observed in past earthquakes. The mechanistic model is transportable and applicable to most types and sizes of bridges. Finally, calibrated damage state definitions are compared with that obtained using experimental findings. Comparison shows excellent consistency among results from analytical, empirical and experimental observations.

关键词： highway bridges nonlinear time history analysis fragility curves threshold damage limits mechanisticmodel calibration

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Potentiality of semiconducting diamond as the base material of millimeter-wave and terahertz IMPATT devices

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Journal of Semiconductors 2014年第3期35卷 39-49页

作者： Aritra Acharyya Suranjana banerjee J.P.banerjee Institute of Radio Physics and Electronics University of Calcutta Academy of Technology West Bengal University of Technology

An attempt is made in this paper to explore the potentiality of semiconducting type-IIb diamond as the base material of double-drift region（DDR） impact avalanche transit time（IMPATT） devices operating at both millimetre-wave（mm-wave） and terahertz（THz） frequencies. A rigorous large-signal（L-S） simulation based on the non-sinusoidal voltage excitation（NSVE） model developed earlier by the authors is used in this study. At first,a simulation study based on avalanche response time reveals that the upper cut-off frequency for DDR diamond IMPATTs is 1.5 THz, while the same for conventional DDR Si IMPATTs is much smaller, i.e. 0.5 THz. The L-S simulationresultsshowthattheDDRdiamondIMPATTdevicedeliversapeakRFpowerof7.79Wwithan18.17%conversion efficiency at 94 GHz; while at 1.5 THz, the peak power output and conversion efficiency decrease to6.19mWand8.17%respectively,taking50%*** diamond and Si shows that the former excels over the later as regards high frequency and high power performance at both mm-wave and THz frequency bands. The effect of band to band tunneling on the L-S properties of DDR diamond and Si IMPATTs has also been studied at different mm-wave and THz frequencies.

关键词： diamond IMPATTs DDR large-signal simulation millimeter-wave terahertz

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Effect of junction temperature on the large-signal properties of a 94 GHz silicon based double-drift region impact avalanche transit time device

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Journal of Semiconductors 2013年第2期34卷 19-30页

作者： Aritra Acharyya Suranjana banerjee J.P.banerjee Institute of Radio Physics and Electronics University of Calcutta92APC RoadKolkata-700009India Academy of Technology West Bengal University of TechnologyAdisaptagramHooghly-712121West BengalIndia

The authors have developed a large-signal simulation technique extending an in-house small-signal simulation code for analyzing a 94 GHz double-drift region impact avalanche transit time device based on silicon with a non-sinusoidal voltage excitation and studied the effect of junction temperature between 300 and 550 K on the large-signal characteristics of the device for both continuous wave （CW） and pulsed modes of operation. Results show that the large-signal RF power output of the device in both CW and pulsed modes increases with the increase of voltage modulation factor up to 60%, but decreases sharply with further increase of voltage modulation factor for a particular junction temperature; while the same parameter increases with the increase of junction temperature for a particular voltage modulation factor. Heat sinks made of copper and type-IIA diamond are designed to carry out the steady-state and transient thermal analysis of the device operating in CW and pulsed modes respectively. Authors have adopted Olson＇s method to carry out the transient analysis of the device, which clearly establishes the superiority of type-IIA diamond over copper as the heat sink material of the device from the standpoint of the undesirable effect of frequency chirping due to thermal transients in the pulsed mode.

关键词： admittance characteristics chirp bandwidth frequency chirping junction temperature large-signal analysis transient thermal analysis

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Deforestation and forest fragmentation in the highlands of Eastern Ghats,India

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Journal of Forestry Research 2021年第3期32卷 1127-1138页

作者： Rakesh Paul Kakoli banerjee Central University of Orissa KoraputOdishaIndia

Tropical forest cover change along with increasing fragmentation has detrimental effects on the global *** the current study change in both forest cover and fragmentation of Koraput district have been assessed in the past three decades(1987-2017)and future decade(2017-2027),which has been modelled using logistic regression showing a gradual decrease in the forest cover and increase in *** long term deforestation rates from 1987 to 2017(current period)and from 1987 to 2027(predicted period)were found to be-0.018 and-0.012,*** of the total geographical area,2027 number of grids(1 km^(2))out of 8856 grids were found to have shown extinction of forest in the study *** conversion of forested lands into other land uses has been one of the major causes of deforestation in Koraput,especially because of the increasing mining activities and establishment of three major industries namely National Aluminium Company(NALCO),Damanjodi,Hindustan Aeronautics Limited(HAL),Sunabeda and Ballarpur Industries Limited(BILT).The forest fragmentation reveals a negative trend,recording highest conversion from large core fragments to edge(191.33 km2)and the predicted period has also shown the same trend of negative change,which poses serious danger to the structure of the *** of all the landscape matrices calculated,number of patches will increase to 214 in 2027 from 93 in *** the test between geographically weighted regression(GWR)and ordinary least square regression(OLS),GWR was the better fit model for drawing a spatial relationship between forest cover and fragmentation *** study confirmed that the forest cover change has impacted the forest fragmentation in the study *** programmes like REDD+should be implemented along with the experiences of Community Forest Management and the joint forest management should be intensified at community level in order to develop better management practices to conserve habitats in biodi

关键词： Forest cover Forest ecosystem Predictive model Forest fragmentation Grid based change Geographically weighted regression

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Comparison and integration of CuInGaSe and perovskite solar cells

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Journal of Energy Chemistry 2023年第3期78卷 463-475,I0013页

作者： Weiguang Chi Sanjay K.banerjee Microelectronics Research Center Department of Electrical and Computer EngineeringThe University of Texas at AustinAustinTexas 78758USA

The rapidly developing perovskite solar cells(PSCs) provide a new and promising choice of thin film solar cells due to their attractive *** the commercialized thin film solar cells,CuInGaSe(CIGS)cells demonstrate higher efficiency than amorphous Si photovoltaic devices and lower toxicity than CdTe ***,a wide variety of studies have been conducted on ***,we elucidate CIGS materials and perovskites as absorber in thin film solar cells in terms of structure and optoelectronic ***,a comparison of PSCs and commercialized CIGS cells is made from the point of view of fabrication process,stability,and *** addition,the integration of CIGS devices and PSCs is elaborated based on tandem ***,prospects for the advancement of CIGS cells and PSCs are discussed.

关键词： CuInGaSe solar cells Perovskite solar cells Process Stability Toxicity Tandem

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Heterojunction DDR THz IMPATT diodes based on Al_xGa_(1-x)N/Ga N material system

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Journal of Semiconductors 2015年第6期36卷 39-46页

作者： Suranjana banerjee Monojit Mitra Academy of Technology West Bengal University of Technology Indian Institute of Engineering Science and Technology

Simulation studies are made on the large-signal RF performance and avalanche noise properties ofhet- erojunction double-drift region （DDR） impact avalanche transit time （IMPATT） diodes based on AlxGal-xN/GaN material system designed to operate at 1.0 THz frequency. Two different heterojunction DDR structures such as n-Al0.4Ga0.6N/p-GaN and n-GaN/p-Al0.4Ga0.6N are proposed in this study. The large-signal output power, con- version efficiency and noise properties of the heterojunction DDR IMPATTs are compared with homojunction DDR IMPATT devices based on GaN and Al0.4Ga0.6N. The results show that the n-Al0.4Ga0.6N/p-GaN heterojunction DDR device not only surpasses the n-GaN/p-Al0.4Ga0.6N DDR device but also homojunction DDR IMPATTs based on GaN and Al0.4Ga0.6N as regards large-signal conversion efficiency, power output and avalanche noise performance at 1.0 THz.

关键词： A1GaN/GaN heterojuntion DDR IMPATTs avalanche noise terahertz frequency

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Energy efficient fault-tolerant multipath routing scheme for wireless sensor networks

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The Journal of China Universities of Posts and Telecommunications 2013年第6期20卷 42-48,61页

作者： Prasenjit Chanak Indrajit banerjee Department of Information Technology Bengal Engineering and Science University

In wireless sensor network （MSN）, reliability is the main issue to design any routing technique. To design a comprehensive reliable wireless sensor network, it is essential to consider node failure and energy constrain as inevitable phenomena. In this paper we present energy efficient node fault diagnosis and recovery for wireless sensor networks referred as energy efficient fault tolerant multipath routing scheme for wireless sensor network. The scheme is based on multipath data routing. One shortest path is used for main data routing in our scheme and other two backup paths are used as alternative path for faulty network and to handle the overloaded traffic on main channel. Shortest pat data routing ensures energy efficient data routing. Extensive simulation results have revealed that the performance of the proposed scheme is energy efficient and can tolerates more than 60% of fault.

关键词： WSN fault tolerance (FT) load balance routing energy efficiency

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Nucleosynthesis in the accretion disks of Type Ⅱ collapsars

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Research in Astronomy and Astrophysics 2013年第9期13卷 1063-1074页

作者： Indrani banerjee Banibrata Mukhopadhyay Department of Physics Indian Institute of Science

We investigate nucleosynthesis inside the gamma-ray burst （GRB） accre- tion disks formed by the Type II collapsars. In these collapsars, the core collapse of massive stars first leads to the formation of a proto-neutron star. After that, an out- ward moving shock triggers a successful supernova. However, the supernova ejecta lacks momentum and within a few seconds the newly formed neutron star gets trans- formed to a stellar mass black hole via massive fallback. The hydrodynamics of such an accretion disk formed from the fallback material of the supernova ejecta has been studied extensively in the past. We use these well-established hydrodynamic models for our accretion disk in order to understand nucleosynthesis, which is mainly ad- vection dominated in the outer regions. Neutrino cooling becomes important in the inner disk where the temperature and density are higher. The higher the accretion rate （M） is, the higher the density and temperature are in the disks. We deal with accre- tion disks with relatively low accretion rates： 0.001 Mo s-1 ~ 3）/~ 0.01 Mo S--1 and hence these disks are predominantly advection dominated. We use He-rich and Si- rich abundances as the initial condition of nucleosynthesis at the outer disk, and being equipped with the disk hydrodynamics and the nuclear network code, we study the abundance evolution as matter inflows and falls into the central object. We investigate the variation in the nucleosynthesis products in the disk with the change in the initial abundance at the outer disk and also with the change in the mass accretion rate. We report the synthesis of several unusual nuclei like 31p, 39K, 43Sc＇ 35C1 and various isotopes of titanium, vanadium, chromium, manganese and copper. We also confirm that isotopes of iron, cobalt, nickel, argon, calcium, sulphur and silicon get synthe- sized in the disk, as shown by previous authors. Much of these heavy elements thus synthesized are ejected from the disk via outflows and hence they should

关键词： accretion accretion disks -- gamma rays: bursts -- black hole physics-- nuclear reactions nucleosynthesis abundances

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Purification and concentration of gluconic acid from an integrated fermentation and membrane process using response surface optimized conditions

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Frontiers of Chemical Science and Engineering 2019年第1期13卷 152-163页

作者： Parimal Pal Ramesh Kumar Subhamay banerjee Environment and Membrane Technology Laboratory Chemical Engineering Department National Institute of Technology Durgapur West Bengal 713209 India Department of Chemistry The University of Burdwan West Bengal 713104 India

A response surface method was used to optimize the purification and concentration of gluconic acid from fermentation broth using an integrated membrane system. Gluconobacter oxydans was used for the bioconversion of the glucose in sugarcane juice to gluconic acid (concentration 45 g·L^-1) with a yield of 0.9 g·g^-1. The optimum operating conditions, such as trans-membrane pressure (TMP), pH, cross-flow rate (CFR) and initial gluconic acid concentration, were determined using response surface methodology. Five different types of polyamide nanofiltration membranes were screened and the best performing one was then used for downstream purification of gluconic acid in a flat sheet cross-flow membrane module. Under the optimum conditions (TMP=12 bar and CFR=400 L·h^-1), this membrane retained more than 85% of the unconverted glucose from the fermentation broth and had a gluconic acid permeation rate of 88% with a flux of 161 L·m^-2·h^-1. Using response surface methods to optimize this green nanofiltration process is an effective way of controlling the production of gluconic acid so that an efficient separation with high flux is obtained.

关键词： gluconic acid optimized nanofiltration green processing process intensification

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Mapping Sensitive Vegetation Communities in Mining Eco-space using UAV-LiDAR

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International Journal of Coal Science & Technology 2022年第3期9卷 185-200页

作者： Bikram Pratap banerjee Simit Raval Agriculture Victoria Grains Innovation Park110 Natimuk Road3400 HorshamVICAustralia School of Minerals and Energy Resources Engineering University of New South Wales2052 SydneyNSWAustralia

Near earth sensing from uncrewed aerial vehicles or UAVs has emerged as a potential approach for fne-scale environmental *** systems provide a cost-efective and repeatable means to acquire remotely sensed images in unprecedented spatial detail and a high signal-to-noise *** is increasingly possible to obtain both physiochemical and structural insights into the environment using state-of-art light detection and ranging(LiDAR)sensors integrated onto *** sensitive environments,such as swamp vegetation in longwall mining areas,is essential yet challenging due to their inherent *** practices for monitoring these remote and challenging environments are primarily *** is partly due to an absent framework and challenges of using UAV-based sensor systems in monitoring such sensitive *** research addresses the related challenges in developing a LiDAR system,including a workfow for mapping and potentially monitoring highly heterogeneous and complex *** involves amalgamating several design components,including hardware integration,calibration of sensors,mission planning,and developing a processing chain to generate usable *** also includes the creation of new methodologies and processing routines to establish a pipeline for efcient data retrieval and generation of usable *** designed systems and methods were applied to a peat swamp environment to obtain an accurate geo-spatialised LiDAR point *** of the LiDAR data was tested against ground-based measurements on various aspects,including visual assessment for generation LiDAR metrices maps,canopy height model,and fne-scale mapping.

关键词： Upland swamps Mine surveying Monitoring Environment sustainability Drones and laser scanning

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