Differential Response of Azolla microphylla Kaulf . and Azolla filiculoides Lam . to Sodium Fluoride

(M . Eyini),(K . Sujanandini),(C . Pothiraj),(M . Jayakumar),(Kil Bong Seop) 한국식물학회 1999 Journal of Plant Biology Vol.42 No.4

Wave load resistance of high strength concrete slender column subjected to eccentric compression

Jayakumar, M.,Rangan, B.V. Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.50 No.3

A computer based iterative numerical procedure has been developed to analyse reinforced high strength concrete columns subjected to horizontal wave loads and eccentric vertical load by taking the material, geometrical and wave load non-linearity into account. The behaviour of the column has been assumed, to be represented by Moment-Thrust-Curvature relationship of the column cross-section. The formulated computer program predicts horizontal load versus deflection behaviour of a column up to failure. The developed numerical model has been applied to analyse several column specimens of various slenderness, structural properties and axial load ratios, tested by other researchers. The predicted values are having a better agreement with experimental results. A simplified user friendly hydrodynamic load model has been developed based on Morison equation supplemented with a wave slap term to predict the high frequency non-linear impulsive hydrodynamic loads arising from steep waves, known as ringing loads. A computer program has been formulated based on the model to obtain the wave loads and non-dimensional wave load coefficients for all discretised nodes, along the length of column from instantaneous free water surface to bottom of the column at mud level. The columns of same size and material properties but having different slenderness ratio are analysed by the developed numerical procedure for the simulated wave loads under various vertical thrust. This paper discusses the results obtained in detail and effect of slenderness in resisting wave loads under various vertical thrust.

Wave load resistance of high strength concrete slender column subjected to eccentric compression

M. Jayakumar,B.V. Rangan 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.50 No.3

A computer based iterative numerical procedure has been developed to analyse reinforced high strength concrete columns subjected to horizontal wave loads and eccentric vertical load by taking the material, geometrical and wave load non-linearity into account. The behaviour of the column has been assumed, to be represented by Moment-Thrust-Curvature relationship of the column cross-section. The formulated computer program predicts horizontal load versus deflection behaviour of a column up to failure. The developed numerical model has been applied to analyse several column specimens of various slenderness, structural properties and axial load ratios, tested by other researchers. The predicted values are having a better agreement with experimental results. A simplified user friendly hydrodynamic load model has been developed based on Morison equation supplemented with a wave slap term to predict the high frequency non-linear impulsive hydrodynamic loads arising from steep waves, known as ringing loads. A computer program has been formulated based on the model to obtain the wave loads and non-dimensional wave load coefficients for all discretised nodes, along the length of column from instantaneous free water surface to bottom of the column at mud level. The columns of same size and material properties but having different slenderness ratio are analysed by the developed numerical procedure for the simulated wave loads under various vertical thrust. This paper discusses the results obtained in detail and effect of slenderness in resisting wave loads under various vertical thrust.

Diagnosis of Incipient Sensor Faults in a Flight Control Actuation System

Jayakumar M,Bijan B Das 제어로봇시스템학회 2006 제어로봇시스템학회 국제학술대회 논문집 Vol.2006 No.10

Neutral beam injector system for Steady State Tokamak -1

S. K. Mattoo,A.K. Chakraborty,B. Prajapati,BVSNNP Sridhar,C. Rotti,Ch. Chakrapani,G. Patel,M. Bandyopadhyay,M.J. Singh,M.R. Jana,N.P. Singh,P. Bharati,P.J. Patel,P.K. Jayakumar,R. Onali,S. Ramababu,S. 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.III

This paper discusses the experimental results obtained from the various components developed for a 1.7 MW neutral beam injector (NBI). Several technologies related to fabrication of back plate, extractor grids, high-current filament feedthru’s, heat-transfer elements, ceramic insulators, cryopumps, rectangular vessels and power supplies have been developed in collaboration with the Indian industry. Control experiments on the prototype plasma box are described.

A Self Intelligent Learner Identification to Increase Self-Efficacy for Enhanced Learning Performance

M. Mohammed Thaha,C. Jayakumar 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.8

Students’ performance on learning is based on the Self-Efficacy and mental efforts. Learning style of a person will be changing based on the environment. Our objective is to improve the self-efficacy and provide the learning content based on the learning style adopted by the learner. This study attempt has been made to classify the e-learning user based on their opinion on a set of parameters. e-learners before commencing their learning process are asked to record their opinion on 16 parameters of a five point scale. 367 e-learners were provided the responses. Based on the responses, the users were categorized to different categories on a statically using factor analysis. The factor analysis provides five components. The components were named based on variables. Thus users were grouped as Multimedia, Modality,Contiguity, Redundancy and personalization learners. A real time agent has also been developed to categorize e-learners based on the 16 parameters thus used in statistical method has also been used. This agent will provide the suitable e-learning content based on the current learning style of the users. This helps in better understanding of the concept. The real time agent categorized the user and the results were compared with statistical method. Moreover, the proposed system analyses the error rate on learning style identified by the system and the one who posses naturally. Out of the 367 users, the real time system identified 357 learners same as in the statistical method with the error rate of 0.046296. Since the error rate was minimal the system thus developed was reliable. Further erroneously categorized by the real time systems were identified and compared with the statistical method. The content of e-learning was delivered to the user by the server according to the type of users based on statistical method. For the remaining 10 users the content were reorganized and delivered to the learner statistically categorized and as well as the real time system category.

Microwave assisted multiwall carbon nanotubes enhancing Cd(II) adsorption capacity in aqueous media

N.M. Mubarak,J.N. Sahu,E.C. Abdullah,N.S. Jayakumar,P. Ganesan 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.24 No.-

Novel multiwall carbon nanotubes (MWCNTs) have been successfully synthesized using tubular microwave chemical vapour deposition technique and proved to be an outstanding adsorbent for the removal of Cd(II) from aqueous solution. The effect of process parameters such as pH, MWCNTs dosage, agitation speed and time were investigated. The maximum adsorption capacities of Cd(II) were found to be 88.62 mg/g and a statistical analysis reveals that the optimum conditions for the highest removal (98%) of Cd(II) are at pH 5, MWCNTs dosage 0.1 g, agitation speed and time of 160 rpm and 50 min, respectively with the initial concentration of 10 mg/L. The Langmuir and Freundlich isotherm models match the experimental data very well and adsorption kinetic obeyed pseudo-second order. Our results proved that MWCNTs can be used as an effective Cd(II) adsorbent due to the high adsorption capacity as well as the short adsorption time needed to achieve equilibrium.

An overview on methods for the production of carbon nanotubes

N.M. Mubarak,E.C. Abdullah,N.S. Jayakumar,J.N. Sahu 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

Carbon nanotubes (CNTs) are one of the most exciting discoveries in nanoscale sciences. A brief survey of experimental work directed towards the synthesis of CNTs has been discussed. The various methods of production of CNTs are explained outlining their capabilities, efficiencies and possible exploitation as economic large scale production. Among the discussed techniques, the chemical vapor deposition (CVD) appears to be the most potential way to produce high quality of CNTs at high yield. The advantages of CVD over other techniques are also explained and the effects of process parameter on the synthesis of these nanomaterials are discussed.

A Novel Double Frequency SEPIC Converter with Improved Transient Characteristics and Efficiency

Vijayalakshmi S.,Marimuthu M.,Jayakumar N.,Vighneshwari B. Devi,Paranthagan B.,Rani Nisha C.,Shenbagalakshmi R. 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.2

A novel double frequency SEPIC converter is discussed in this paper. Effi ciency, static and dynamic characteristics of the dc to dc power converters are the concerned factors in power electronics. In order to improve the above factors, switching frequency play a vital role in converters. Hence, include High switching frequency in the converter can improve the dynamic characteristics, but it reduces the effi ciency. In other words, put in low switching frequency in the converter may result in better effi ciency but produces poor dynamic characteristic. In this concern double-frequency SEPIC converter is proposed. This SEPIC dc-dc converter consists of two SEPIC cells: one functions at high switching frequency, and other functions at low switching frequency. The proposed SEPIC converter reveals enhanced steady state and transient characteristic than the other single frequency SEPIC converter and produces high effi ciency also. The results of simulation and hardware prove that the anticipated converter extremely progresses the effi ciency and displays more or less equal the same dynamics as the traditional high frequency SEPIC converter.

Characterization of Brain Dysfunction Induced by Bacterial Lipopeptides That Alter Neuronal Activity and Network in Rodent Brains

Kim, Kwang-Min,Zamaleeva, Alsu I.,Lee, Youn Woo,Ahmed, M. Rafiuddin,Kim, Eunkyung,Lee, Hye-Ryeon,Pothineni, Venkata Raveendra,Tao, Juan,Rhee, Siyeon,Jayakumar, Mithya,Inayathullah, Mohammed,Sivanesan, Society for Neuroscience 2018 The Journal of neuroscience Vol.38 No.50

<P>The immunopathological states of the brain induced by bacterial lipoproteins have been well characterized by using biochemical and histological assays. However, these studies have limitations in determining functional states of damaged brains involving aberrant synaptic activity and network, which makes it difficult to diagnose brain disorders during bacterial infection. To address this, we investigated the effect of Pam<SUB>3</SUB>CSK<SUB>4</SUB> (PAM), a synthetic bacterial lipopeptide, on synaptic dysfunction of female mice brains and cultured neurons in parallel. Our functional brain imaging using PET with [<SUP>18</SUP>F]fluorodeoxyglucose and [<SUP>18</SUP>F] flumazenil revealed that the brain dysfunction induced by PAM is closely aligned to disruption of neurotransmitter-related neuronal activity and functional correlation in the region of the limbic system rather than to decrease of metabolic activity of neurons in the injection area. This finding was verified by <I>in vivo</I> tissue experiments that analyzed synaptic and dendritic alterations in the regions where PET imaging showed abnormal neuronal activity and network. Recording of synaptic activity also revealed that PAM reorganized synaptic distribution and decreased synaptic plasticity in hippocampus. Further study using <I>in vitro</I> neuron cultures demonstrated that PAM decreased the number of presynapses and the frequency of miniature EPSCs, which suggests PAM disrupts neuronal function by damaging presynapses exclusively. We also showed that PAM caused aggregation of synapses around dendrites, which may have caused no significant change in expression level of synaptic proteins, whereas synaptic number and function were impaired by PAM. Our findings could provide a useful guide for diagnosis and treatment of brain disorders specific to bacterial infection.</P><P><B>SIGNIFICANCE STATEMENT</B> It is challenging to diagnose brain disorders caused by bacterial infection because neural damage induced by bacterial products involves nonspecific neurological symptoms, which is rarely detected by laboratory tests with low spatiotemporal resolution. To better understand brain pathology, it is essential to detect functional abnormalities of brain over time. To this end, we investigated characteristic patterns of altered neuronal integrity and functional correlation between various regions in mice brains injected with bacterial lipopeptides using PET with a goal to apply new findings to diagnosis of brain disorder specific to bacterial infection. In addition, we analyzed altered synaptic density and function using both <I>in vivo</I> and <I>in vitro</I> experimental models to understand how bacterial lipopeptides impair brain function and network.</P>