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Microbial stabilisation and kinetic enhancement of marine methane hydrates in both deionised-and sea-water

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Petroleum 2021年第4期7卷 402-406页

作者： Mohammad reza Ghaani Jonathan M.Young Prithwish K.nandi Shamsudeen Dandare Christopher C.rAllen Niall J.English School of Chemical and Bioprocess Engineering University College DublinBelfieldDublin 4Ireland School of Biological Sciences Queen's University BelfastUniversity RoadBelfastBT71NNNorthern IrelandUK

The large quantity of marine methane hydrates has driven substantial interest in methane-gas-fuel potential,especially with the qualified success of Shensu(2017)and Nankai-Trough(2014&17)production trials via depressurisation(blighted ultimately by sanding out),building on an earlier Malik-2008 trial for permafrost-bound *** particular,obviating deep-water-drilling approaches,such as the MeBO production rig(without such a drill bit),together with blowout preventers,constitutes a tantalising cost-saving *** means of addressing sand production by customised gravel packs,wellbore screens and slotted liners with from-seafloor drilling will be expected to lead to future production-trial ***,despite these exciting engineering advances and a few marinemimicking laboratory studies of methane-hydrate kinetics and stabilisation from microbial perspectives,relatively little is known about the thermogenic or microbial origin of marine hydrates,nor their possible formation kinetics or potential stabilisation by microbial sources as an exponent of Gaia's hypothesis,or within the context of“Gaia's breath”as regards global methane‘exhalations’.Here,for the first time,we elucidate the methylotrophic-microbial basis for kinetic enhancement and stabilisation of marine-hydrate formation in both deionised-and sea-water,identifying the key protein at play,which has some similarity to porins in other methylotrophic *** so doing,we suggest such phenomena in marine hydrates as evidence of Gaia's hypothesis.

关键词： Gas hydrate Microbes Methylotrophs

Characteristics of Dispersed ZnO-Folic Acid Conjugate in Aqueous Medium

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Advances in Nanoparticles 2014年第1期3卷 23-30页

作者： Sreetama Dutta Bichitra nandi Ganguly Applied Nuclear Physics Division Saha Institute of Nuclear Physics Kolkata India

The focus of this article is based on the aqueous dispersed state properties of inorganic ZnO nanoparticles (average size ≤ 4 nm), their surface modification and bio-functionalization with folic acid at physiological pH ~ 7.5, suitable for bio-imaging and targeted therapeutic application. While TEM studies of the ZnO nano-crystallites have been performed to estimate their size and morphology in dry state, the band gap properties of the freshly prepared samples, the hydrodynamic size in aqueous solution phase and the wide fluorescence range in visible region have been investigated to establish the fact that the sol is particularly suitable for bio-medical purpose in the aqueous dispersed state.

关键词： ZnO Nanoparticle Folic Acid Band Gap Hydrodynamic Size Fluorescence

Detection of Different Stages of Alzheimer’s Disease Using CNN Classifier

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Computers, Materials & Continua 2023年第9期76卷 3933-3948页

作者： S M Hasan Mahmud Md Mamun Ali Mohammad Fahim Shahriar Fahad Ahmed Al-Zahrani Kawsar Ahmed Dip nandi Francis M.Bui Department of Computer Science American International University-Bangladesh(AIUB)Dhaka1229Bangladesh Centre for Advanced Machine Learning and Applications(CAMLAs) DhakaBangladesh Department of Software Engineering Daffodil International UniversityDhakaBangladesh Department of Computer Engineering Umm Al-Qura UniversityMecca24381Saudi Arabia Department of ECE University of SaskatchewanSaskatoonSK S7N5A9Canada Group of Biophotomatiχ Department of ICTMBSTUSantoshTangail1902Bangladesh

Alzheimer’s disease(AD)is a neurodevelopmental impairment that results in a person’s behavior,thinking,and memory *** common symptoms ofADare losingmemory and early *** addition to these,there are several serious impacts ***,the impact ofADcanbemitigatedby early-stagedetection though it cannot be cured ***-stage detection is the most challenging task for controlling and mitigating the impact of *** study proposes a predictive model to detect AD in the initial phase based on machine learning and a deep learning approach to address the *** build a predictive model,open-source data was collected where five stages of images of AD were available as Cognitive Normal(CN),Early Mild Cognitive Impairment(EMCI),Mild Cognitive Impairment(MCI),Late Mild Cognitive Impairment(LMCI),and *** stage of AD is considered as a class,and then the dataset was divided into three parts binary class,three class,and five *** this research,we applied different preprocessing steps with augmentation techniques to efficiently *** integrates a random oversampling technique to handle the imbalance problem from target classes,mitigating the model overfitting and *** three machine learning classifiers,such as random forest(rF),K-Nearest neighbor(KNN),and support vector machine(SVM),and two deep learning methods,such as convolutional neuronal network(CNN)and artificial neural network(ANN)were applied on these *** analyzing the performance of the used models and the datasets,it is found that CNN with binary class outperformed 88.20%*** result of the study indicates that the model is highly potential to detect AD in the initial phase.

关键词： Alzheimer’s disease early detection convolutional neural network data augmentation random oversampling machine learning

Artificial Intelligence Based Model for Channel Status Prediction: A New Spectrum Sensing Technique for Cognitive radio

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International Journal of Communications, Network and System Sciences 2013年第3期6卷 139-148页

作者： Sandhya Pattanayak Palanaindavar Venkateswaran rabindranath nandi Department of Electronics and Communication Jadavpur University Kolkata India Department of Electronics and Communication Narula Institute of Technology Kolkata India

The recent phenomena of tremendous growth in wireless communication application urge increasing need of radio spectrum, albeit it being a precious but natural resource. The recent technology under development to overview the situation is the concept of Cognitive radio (Cr). recently the Artificial Intelligence (AI) tools are being considered for the topic. AI is the core of the cognitive engine that examines the external and internal environment parameters that leads to some postulations for QoS improvement. In this article, we propose a new Artificial Neural Network (ANN) model for detection of a spectrum hole. The model is trained with some pertinent features over a channel like SNr, channel capacity, bandwidth efficiency etc. The channel capacity status could be identified in a quantized index form . Some simulation results are presented.

关键词： ANN Cognitive radio Spectrum Sensing Cognitive Engine

A Single resistor Tunable Grounded Capacitor Dual-Input Differentiator

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Circuits and Systems 2015年第3期6卷 49-54页

作者： Koushick Mathur Palaniandavar Venkateswaran rabindranath nandi Department of Electronics & Communication Engineering UIT University of Burdwan Bardhaman India Department of Electronics & Telecommunication Engineering Jadavpur University Kolkata India

A new current feedback amplifier (CFA) based dual-input differentiator (DID) design with grounded capacitor is presented;its time constant (τo) is independently tunable by a single resistor. The proposed circuit yields a true DID function with ideal CFA devices. Analysis with nonideal devices having parasitic capacitance (Cp) shows extremely low but finite phase error (θe);suitable design θe could be minimized significantly. The design is practically active-insensitive relative to port mismatch errors (ε) of the active element. An allpass phase shifter circuit implementation is derived with slight modification of the differentiator. Satisfactory experimental results had been verified on typical wave processing and phase-selective filter design applications.

关键词： CFA Tunable Differentiator Dual-Input Differentiator Wave Shaper

Environmental radiation Measurement and Assessment of Natural radioactivity in Soil, Water and Vegetation

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Journal of Applied Mathematics and Physics 2018年第11期6卷 2330-2337页

作者： nandi-Esom Chariette Ereh Meng Zhang Nuclear Science and Technology Harbin Engineering University Harbin China

Environmental radioactivity is produced by radioactive materials in the human environment. While some radioisotopes, such as strontium-90 (90Sr) and technetium-99 (99Tc), are only found on Earth as a result of human activity, and some, like potassium-40 (40K), are only present due to natural processes, a few isotopes, e.g. tritium (3H), result from both natural processes and human activities. The concentration and location of some natural isotopes, particularly uranium-238 (238U), can be affected by human activity because of the constant exposure of Human beings to radiation caused by terrestrial, extra-terrestrial and anthropogenic radio nuclides, it is necessary to determine and estimate the activity of various radio nuclides in environmental media such as vegetation, soil, and water. In the present research, the activities of 226ra, 232Th and 40K are measured in soil, vegetation and water samples, collected from Yangdong District, Yangxi County, and Yangjiang County of Guangdong Province, China using an HPGe based gamma spectrometry system. The measured mean activity of 226ra, 232Th and 40K in soil samples was found to be 31.19 ± 1.2, 47.00 ± 2.30 and 589.31 ± 17.52 Bqkg-1, respectively. The measured mean activity of these radionuclides in all water samples was found to be below minimum detectable activity. The measured mean activity of 226ra, 232Th and 40K in vegetation samples was 19.92 ± 3.09, 25.36 ± 8.11 and 4982.94 ± 85.68 Bqkg-1, respectively. No anthropogenic 137Cs was detected in these environmental samples. Mean radium equivalent activity (raeq), external radiation hazard index (Hex), internal radiation hazard index (Hin) and absorbed dose rate (D) for the area under study were determined as 142.92 Bqkg-1, 0.38, 0.47 and 66.47 nGyh-1, respectively. The annual effective dose equivalent (AEDE) varied in the range from 0.03 to 0.12 mSvy-1. It is concluded that the surveyed area do not pose any significant radiological risk to the population and environment

关键词： High Purity Germanium Detector radium Thorium Potassium radium Equivalent Activity radiation Hazard Indices and Environment Measure-ment

MMCC Based Electronically Tunable Allpass Filters Using Grounded Synthetic Inductor

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Circuits and Systems 2014年第4期5卷 89-97页

作者： rabindranath nandi Palaniandavar Venkateswaran Mousiki Kar Department of Electronics & Communication Engineering Heritage Institute of Technology Kolkata India Department of Electronics & Telecommunication Engineering Jadavpur University Kolkata India

New circuit implementations of electronically tunable first and second order allpass filter (AP) structures using a Multiplication Mode Current Conveyor (MMCC) building block are presented. The control voltage (V) of the MMCC tunes the desired phase (θ) while the time constant (τ) is adjustable by a Differential Voltage Current Conveyor Transconductance Amplifier (DVCCTA)-based synthetic lossless grounded inductor (L). The circuits are analyzed taking into account the device imperfections which show low active sensitivity features of the designs. The effects of port transfer error (ε) and that of the parasitic capacitances of the active devices had been meticulously examined which indicated that certain deviations in nominal design equations occur;these however, could be minimized with appropriate choice of the circuit passive components. readily available AD-844 type Current Feedback Amplifier (CFA) elements are utilized for the topology implementation. Satisfactory test results on electronic θ-tunability, upto about 300 KHz, had been verified by PSPICE simulation and with hardware experimentation.

关键词： Allpass Filter MMCC DVCCTA CFA Synthetic Inductor Electronic Phase Shifter

Selective Filters and Tunable Sinusoid Oscillator Using a CDBA

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Circuits and Systems 2013年第2期4卷 227-232页

作者： rabindranath nandi Palaniandavar Venkateswaran Sagarika Das B. P. Poddar Institute of Management & Technology Kolkata India Department of Electronics & Telecommunication Engineering Jadavpur University Kolkata India

The realization of some new selective filters using single current differencing buffered amplifier (CDBA) and few rC components is presented. The same topology provides lowpass (LP), bandpass (BP) and highpass (HP) characteristics with appropriate choice and location of the rC components in the circuit. Incorporation of a suitable feedback loop through a voltage buffer unity-gain cell yields a tunable sinusoid oscillator. Effects of the device port mismatch errors (ε) and parasitic z-node capacitance (Cz) of the CDBA element are shown to be insignificant and corresponding sensitivities are extremely low. Satisfactory experimental verifications of the filter quality (Q) and oscillator tuning range (500 KHz ≤ fo ≤ 5 MHz) are carried out.

关键词： Current Differencing Buffered Amplifier Selective Filter Sinewave Generator Tunable Oscillator

New Integrators and Differentiators Using a MMCC

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Circuits and Systems 2012年第3期3卷 288-294页

作者： Palaniandavar Venkateswaran rabindranath nandi Sagarika Das B. P. Poddar Institute of Management & Technology Kolkata-700052 India Department of Electronics & Telecommunication Engineering Jadavpur University Kolkata-700032 India

Using the new building block Multiplication-Mode Current Conveyor (MMCC), some inverting/non-inverting type integrator and differentiator designs are presented, wherein the time constant (τ) is tuned electronically. The MMCC is implemented by a readily available chip-level configuration using a multiplier (ICL 8013) and a current feedback amplifier (AD-844 IC) CFA. Detailed analysis, taking into account the device non-idealities, had been carried out that indicates slight deviations affecting the values of the nominal time constant but the design is practically insensitive to the port mismatch errors (ε). Satisfactory response on wave conversion, for signal frequencies up to 600 Khz had been verified with both hardware circuit test and PSPICE macromodel simulation.

关键词： Voltage-Controlled Oscillator Multiplication Mode Current Conveyor (MMCC) Current Feedback Opamp (CFA) Quadrature Oscillator