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study of Pulsed Plasma in a Crossed Flow Dielectric barrier Discharge Reactor for Improvement of NO_x Removal in Raw Diesel Engine Exhaust

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Plasma science and Technology 2011年第1期13卷 82-87页

作者： sankarsan MOHAPATRO b.s.RAJANIKANTH High Voltage Lab Indian Institute of Science

Improved performance of plasma in raw engine exhaust treatment is reported. A new type of reactor referred to as of cross-flow dielectric barrier discharge （DbD） was used, in which the gas flow is perpendicular to the corona electrode. In raw exhaust environment, the cross-flow （radial-flow） reactor exhibits a superior performance with regard to NOx removal when compared to that with axial flow of gas. Experiments were conducted at different flow rates ranging from 2 L/min to 25 L/min. The plasma assisted barrier discharge reactor has shown encouraging results in NOx removal at high flow rates.

关键词： electric discharges NOx removal, non-thermal plasma, raw diesel engine exhaust

Output only modal identification and structural damage detection using time frequency & wavelet techniques

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Earthquake Engineering and Engineering Vibration 2009年第4期8卷 583-605页

作者： s.Nagarajaiah b.b.su Dept.of Civil & Environmental Eng.and Dept.of Mechanical Eng.& Material sc. Rice University Dept.of Civil Structural& Environmental Eng.Trinity College Dublin

The primary objective of this paper is to develop output only modal identification and structural damage detection. Identification of multi-degree of freedom （MDOF） linear time invariant （LTI） and linear time variant （LTV--due to damage） systems b.sed on Time-frequency （TF） techniques--such as short-time Fourier transform （sTFT）, empirical mode decomposition （EMD）, and wavelets--is proposed. sTFT, EMD, and wavelet methods developed to date are reviewed in detail. In addition a Hilbert transform （HT） approach to determine frequency and damping is also presented. In this paper, sTFT, EMD, HT and wavelet techniques are developed for decomposition of free vibration response of MDOF systems into their modal components. Once the modal components are obtained, each one is processed using Hilbert transform to obtain the modal frequency and damping ratios. In addition, the ratio of modal components at different degrees of freedom facilitate determination of mode shape. In cases with output only modal identification using ambient/random response, the random decrement technique is used to obtain free vibration response. The advantage of TF techniques is that they arc signal b.sed; hence, can be used for output only modal identification. A three degree of freedom 1：10 scale model test structure is used to validate the proposed output only modal identification techniques b.sed on sTFT, EMD, HT, wavelets. both measured free vibration and forced vibration （white noise） response are considered. The secondary objective of this paper is to show the relative ease with which the TF techniques can be used for modal identification and their potential for real world applications where output only identification is essential. Recorded ambient vibration data processed using techniques such as the random decrement technique can be used to obtain the free vibration response, so that further processing using TF b.sed modal identification can be performed.

关键词： Time-frequency methods short time Fourier transform Hilbert transform wavelets modal identification:output only structural health monitoring damage detection

Paraconductivity study in Erba_2Cu_(3-x)M_xO_(7-δ)(M=Zn, Fe) superconductors

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Chinese Physics b 2013年第11期22卷 562-568页

作者： A.sedky s.b.Mohamed Physics Department Faculty of Science King Faisal University Physics Department Faculty of Science Assiut University

We report here the paraconductivity of Erba2Cu3-xMxO7-δ （M = Zn and Fe） superconductors. The logarithmic plots of excess conductivity Δσ and reduced temperature C reveal two different exponents corresponding to crossover temperature as a result of shifting the order parameter from 2 to 3. The first exponent in the normal field region is close to 1, in which the order parameter dimensionality （OPD） is 2. The second exponent in the critical field region is close to 0.5, in which the OPD is 3. The coherence length, interlayer coupling, interlayer separation and carrier concentration decrease with increasing doping content, and their values for Fe samples are different from those of Zn samples. While anisotropy is increased with increasing doping content, it is generally higher for a Zn sample than that for an Fe sample. We also estimate several physical parameters such as upper critical magnetic fields in the a–b plane and along the c axis （bab and bc）, and critical current density J at 0 K. Although bab and bc are generally increased with doping content increasing, the value of bab is found to be twice more than that of bc. A similar behavior is obtained for J （0 K） and its value is higher in the Fe sample than that in the Zn sample. These results are discussed in terms of oxygen deficiency, localization of carriers, and flux pinning, which are produced by doping.

关键词： ceramics chemical synthesis X-ray diffraction electrical properties transport properties

spin texturing in quantum wires with Rashba and Dresselhaus spin-orbit interactions and in-plane magnetic field

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Chinese Physics b 2016年第1期25卷 750-756页

作者： b Gisi s sakiroglu I sokmen Physics Department Graduate School of Natural and Applied SciencesDokuz Eyll Universityizmir 35390Turkey Physics Department Faculty of ScienceDokuz Eyll Universityizmir 35390Turkey

In this work, we investigate the effects of interplay of spin-orbit interaction and in-plane magnetic fields on the electronic structure and spin texturing of parabolically confined quantum wire. Numerical results reveal that the competing effects between Rashba and Dresselhaus spin--orbit interactions and the external magnetic field lead to a complicated energy spectrum. We find that the spin texturing owing to the coupling between subbands can be modified by the strength of spin- orbit couplings as well as the magnitude and the orientation angle of the external magnetic field.

关键词： spin-orbit coupling quantum wire spin texture

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)b.sed 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

Earth return path impedances of underground cable for three-layer earth

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Journal of Zhejiang University-science A(Applied Physics & Engineering) 2009年第8期10卷 1191-1198页

作者： b.HEMMATIAN b.VAHIDI s.H.HOssEINIAN Department of Electrical Engineering Amirkabir University of Technology

One of the factors that affect the parameters of an underground cable is earth return path *** developed a formula for the case of one-layer(homogenous) *** in practice the earth is composed of several *** this study we develop a new formula for earth return path impedance in the case of a three-layer *** check the accuracy of the obtained results,a comparison has been made with the finite element method(FEM).A comparison between the results of the Pollaczek formula and results of the obtained formula for a three-layer earth has been made,showing that the use of the Pollaczek formula instead of the actual formula can cause serious errors.

关键词： Underground cables Earth return path impedance Earth stratification Finite element method (FEM)

Dye reduction-b.sed electron-transfer activity monitoring assay for assessing microbial electron transfer activity of microbial fuel cell inocula

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Journal of Environmental sciences 2020年第10期32卷 171-177页

作者： Kartik s.Aiyer Roshan Rai b.s.Vijayakumar Department of biosciences Sri Sathya Sai Institute of Higher LearningPrasanthi NilayamPuttaparthiAndhra Pradesh-515134India

Microbial fuel cells (MFC) utilize microb.s as catalysts to convert chemical energy to *** used for MFC operation must therefore contain active microbial *** dye reduction-b.sed electron-transfer activity monitoring (DREAM) assay was employed to evaluate different inocula used in MFCs for their microbial bioelectrical *** assay utilizes the redox property of Methylene blue to undergo color change from blue to colorless state upon microbial *** extent of Methylene blue reduction was denoted as the DREAM assay *** assay was initially performed on a microbial culture along with the growth curve and estimation of colony forming units (CFUs).DREAM coefficient correlated to the CFU/m L obtained over time as growth *** assay was then extended to water samples (domestic sewage,lake and a man-made pond) serving as inocula in *** wastewater gave the highest DREAM coefficient (0.300±0.05),followed by pond (0.224±0.07) and lake (0.157±0.04) water *** density obtained conformed to the DREAM coefficient values,with the three samples generating power densities of 46.45±5.1,36.12±3.2 and 25.08±4.3 m W/m^2 *** have also studied the role of addition of various carbon sources and their concentrations towards improving the sensitivity of the *** DREAM assay is a rapid,easy-to-perform and cost-effective method to assess inocula for their suitability as anolytes in terms of electron transfer potential in MFCs.

关键词： Dye reduction Electron transfer Methylene blue Microbial fuel cell Wastewater

Effect of bagasse ash reinforcement on the wear behaviour of Al-Cu-Mg/bagasse ash particulate composites

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Acta Metallurgica sinica(English Letters) 2010年第2期23卷 81-89页

作者： V.s. Aigbodion s.b. Hassan G.b. Nyior T. Ause Department of Metallurgical and Materials Engineering Ahmadu Bello University

The effect of bagasse ash （bAp） particle reinforcement on the wear behavior of Al-Cu- Mg alloy has been studied. bagasse ash particles were varied from 0 wt pct-10 wt pct with interval of 2 wt pct. Unlubricated pin-on disc tests were conducted to examine the wear behaviour of the aluminium alloy/bagasse ash particulate composites. The tests were conducted at varying loads, from 5 to 20 N and sliding speeds of 1.26 m/s, 2.51 m/s, 3.77 m/s and 5.02 m/s for a constant sliding distance of 5000 m. The results showed that the wear rates of the A1-Cu-Mg/bAp composites are lower than that of the matrix alloy and further decrease with increasing bagasse ash content. Wear rate increases as the sliding speed and applied load increase. The microstructure of the worn surface revealed that a large amount of plastic deformation appeared on the surface of the unreinforced alloy. While bagasse ash reinforced Al-Cu-Mg alloy showed worn out surface that is not smooth, and grooves, scratches and parallel lines were observed. A combination of adhesion and delamination wear was in operation. These results show that improve wear properties is achievable for the aluminium alloy by the addition of bagasse ash particles as reinforcement material.

关键词： Al-Cu-Mg alloy bagasse ash Composites Load sliding speed and Wear

Quantized autoencoder(QAE)intrusion detection system for anomaly detection in resource-constrained loT devices using RT-loT2022 dataset

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Cybersecurity 2024年第2期7卷 13-27页

作者： b.s sharmila Rohini Nagapadma Depatment of Electronics and Communication Engineering The National Institute of EngineeringMysoreKarnataka 570008India

In recent years,many researchers focused on unsupervised learning for network anomaly detection in edge devices to identify *** deployment of the unsupervised autoencoder model is computationally expensive in resource-constrained edge *** study proposes quantized autoencoder(QAE)model for intrusion detection systems to detect *** is an optimization model derived from autoencoders that incorporate pruning,clustering,and integer quantization *** autoencoder uint8(QAE-u8)and quantized autoencoder float16(QAE-f16)are two variants of QAE built to deploy computationally expensive Al models into Edge ***,we have generated a Real-Time Internet of Things 2022 dataset for normal and attack *** autoencoder model operates on normal traffic during the training *** same model is then used to reconstruct anomaly traffic under the assumption that the reconstruction error(RE)of the anomaly will be high,which helps to identify the ***,we study the performance of the autoencoders,QAE-u8,and QAE-f16 using accuracy,precision,recall,and F1 score through an extensive experimental *** showed that QAE-u8 outperforms all other models with a reduction of 70.01%in average memory utilization,92.23%in memory size compression,and 27.94%in peak CPU ***,the proposed QAE-u8 model is more suitable for deployment on resource-constrained IoT edge devices.

关键词： IoT constrained system