Prabu Natarajan | Central Electrochemical Research Institute (original) (raw)

Papers by Prabu Natarajan

Polymers for Advanced Technologies, 2015

An effectual functionalized synthetic resin involving anthranilic acid/4-nitroaniline/formaldehyd... more An effectual functionalized synthetic resin involving anthranilic acid/4-nitroaniline/formaldehyde was synthesized for the detoxification of hazardous metal ions. The resin was characterized by Fourier transform infrared, 1 H, and 13 C nuclear magnetic resonance spectroscopy, and its morphology was established through scanning electron microscope and X-ray diffraction. The resin was analyzed by thermogravimetric analysis to assess the thermal stability, in which the resin could be used in high temperature aqueous solutions for the elimination of harmful metal ions. The ion-exchange property of the resin was evaluated by batch technique for specific metal ions viz. Fe 3+ , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ , and Pb 2+. The study was extended to three variations such as effect of metal ion uptake in the presence of various electrolytes in different concentrations, effect of pH, and effect of contact time. The outcome proved that the resin can be used as a strong cation-exchanger to remove various metal ions from the solutions. The resin could be regenerated and reused with quantitative recovery of metal ions for few cycles. On comparison with the earlier reported resins, the synthesized resin has found excellent capability of metal ion recovery. The resin possesses an utmost ion-exchange capacity, which is in good harmony with isotherm models and kinetics.

Separation Science and Technology, 2015

ABSTRACT Chelating terpolymer resin was synthesized and characterized by elemental, physico-chemi... more ABSTRACT Chelating terpolymer resin was synthesized and characterized by elemental, physico-chemical, spectral, SEM, XRD and GPC to elucidate the structure and properties of the terpolymer. Ion-exchange analysis involving evaluation of metal ion uptake in different electrolyte concentrations, pH and time have been studied to assess the retention capacities of the terpolymer for the metal ions viz. Fe3+, Co2+, Ni2+, Cu2+, Zn2+ and Pb2+. The adsorption isotherm was evaluated using Langmuir and Freundlich and the results were found best fitting with each other. The resin can be successfully used in the field of recovery of metal ions from effluents and contaminated water.

Applied Organometallic Chemistry, 2014

ABSTRACT Polymeric metal complexes were prepared using a synthesized novel terpolymer ligand invo... more ABSTRACT Polymeric metal complexes were prepared using a synthesized novel terpolymer ligand involving anthranilic acid-o-toluidine-formaldehyde by a polycondensation technique. The synthesized ligand and its metal complexes were characterized using elemental analysis and molar conductivity measurements, and FT-IR, electronic, electron spin resonance and NMR ((1)Hand C-13) spectral methods. The surface morphology and the nature of the synthesized compounds were examined using scanning electronmicroscopy and X-ray diffraction. The thermal stabilities of the ligand and its metal complexes were determined using thermogravimetric analysis (TGA). From the TGA results, various kinetic parameters, i.e. activation energy and order of reaction, and thermodynamic parameters, i.e. entropy change, apparent entropy, frequency factor and free energy change, were determined using the Freeman-Carroll and Sharp-Wentworth methods. In addition, a thermal degradation model was also proposed using the Phadnis-Deshpande method. The thermal stability of the ligand and its metal complexes was found to be appreciably high; in particular, the ligand showed very high stability compared to its metal complexes due to intramolecular hydrogen bonding. Furthermore, the synthesized compounds were subjected to in vitro antibacterial studies with various microorganisms. The results of the studies confirmed that the compounds showed better antibacterial results than a standard antibacterial drug. Copyright (C) 2014 John Wiley & Sons, Ltd.

Advances in Polymer Technology, 2014

A novel terpolymer ligand involving 2-amino-6-nitro-benzothiazole-semicarbazide-formaldehyde was ... more A novel terpolymer ligand involving 2-amino-6-nitro-benzothiazole-semicarbazide-formaldehyde was synthesized in a 1:1:2 mole ratio with a dimethylformamide reaction medium at 150 ± 2°C for 6 h. The synthesized ligand was used to prepare various metal complexes with Cu 2+ , Ni 2+ , and Zn 2+ metal ions. The structure of the terpolymer ligand and its complexes were confirmed based on elemental analysis, molecular weight measurements, molar conductivity, magnetic susceptibilities, Fourier transform infrared, electronic, electron spin resonance, and 1 H and 13 C nuclear magnetic resonance spectroscopy. Scanning electronic microscopy and X-ray diffraction method were used to analyze the morphological features of the terpolymer and its metal complexes. The thermal stabilities of the terpolymer and its metal complexes were determined using thermogravimetric analysis. Kinetic parameters such as activation energy (E a) and order of reaction (n), thermodynamic parameters, viz. entropy change (S), free energy change (F), apparent entropy (S*), and frequency factor (Z) were calculated using Sharp-Wentworth and Freeman-Carroll methods. The thermal degradation mechanism was also proposed for both the terpolymer ligand and its complexes using the Phadnis-Deshpande method. The terpolymer ligand and its complexes were screened for antibacterial activities against selected microorganisms such as Shigella sonnei, Escherichia coli, Klebsiella species, Staphylococcus aureus, Bacillus subtilis, and Salmonella typhimurium.

International …, 2010

... Acknowledgment The authors thank the Management &amp;amp;amp;amp; Principal of Jamal ... more ... Acknowledgment The authors thank the Management &amp;amp;amp;amp; Principal of Jamal Mohamed College (Autonomous), Tiruchirappalli, Tamil Nadu, India for their support and encouragement. References ... Funct. Polym., vol. 31, pp. 111-116, 1996. [10] RS Azarudeen, MA Riswan Ahamed ...

Journal of Materials Chemistry A, 2013

2015 IEEE/WIC/ACM International Conference on Web Intelligence and Intelligent Agent Technology (WI-IAT), 2015

In this paper, we propose a new concept called subject-keyphrase and also introduce a method to e... more In this paper, we propose a new concept called subject-keyphrase and also introduce a method to extract subject-keyphrases from a document. Subject-keyphrases refer to the words or phrases used to represent the sentence subjects of a document, i.e., the content of a document is organized around the subjects of the document. It can be expected that each sentence of a document is composed of a subject and an object, where the subject is defined in relation to its object. Using "definition" and "use" relations, we may thus identify the subjects in a given document by looking for keyphrases which appear frequently as subjects of sentences in the document. We thus present a subject-keyphrase extraction (SKE) algorithm based on the notion of definition-use chain (DU Chain) to identify subject-keyphrases. Experimental results show that SKE can successfully identify the subject-keyphrases to effectively capture the main idea of a document.

2021 IEEE/CVF Conference on Computer Vision and Pattern Recognition Workshops (CVPRW), 2021

Radar has long been a common sensor on autonomous vehicles for obstacle ranging and speed estimat... more Radar has long been a common sensor on autonomous vehicles for obstacle ranging and speed estimation. However, as a robust sensor to all-weather conditions, radar’s capability has not been well-exploited, compared with camera or LiDAR. Instead of just serving as a supplementary sensor, radar’s rich information hidden in the radio frequencies can potentially provide useful clues to achieve more complicated tasks, like object classification and detection. In this paper, we propose a new dataset, named CRUW1, with a systematic annotator and performance evaluation system to address the radar object detection (ROD) task, which aims to classify and localize the objects in 3D purely from radar’s radio frequency (RF) images. To the best of our knowledge, CRUW is the first public large-scale dataset with a systematic annotation and evaluation system, which involves camera RGB images and radar RF images, collected in various driving scenarios.

2017 IEEE 10th Conference on Service-Oriented Computing and Applications (SOCA), 2017

Open educational resources (OER) are important assets for students or teachers, used to help them... more Open educational resources (OER) are important assets for students or teachers, used to help them search for useful resources. However, it is a challenge to improve the user engagement of OER. In this paper, we propose a system, called resource delivery service system (RDSS), in the Taiwan Open Platform for Educational Resources (TOPER) that actively recommends educational resources to users. RDSS includes three modules: high-quality resource identification, teaching subject identification, and teacher attribute identification. These modules can be used to recommend resources to users of TOPER. We applied deep learning and support vector machine to construct these modules in RDSS. The experimental results demonstrated that RDSS can achieve an accuracy of 86% in high-quality resource identification, an accuracy over 88% in teaching subject identification, and an accuracy of 86% in teacher attribute identification.

2016 IEEE/WIC/ACM International Conference on Web Intelligence (WI), 2016

Framing is a phenomenon that is studied and debated widely in sociology and political science. It... more Framing is a phenomenon that is studied and debated widely in sociology and political science. It refers to the manner in which audiences interpret information and justify their claims or activities. The subconscious influence of framing might lead to opinion changes and social movements. However, multi-frame classification on microblogging data has not yet been investigated. In this study, we aim to classify a large number of posts into frames. We describe in detail the implementation of a new algorithm for multi-frame classification tasks called Frame Dispatcher, which aims to classify microblogging data into frames. In our experiments, we extracted over 15,000 posts from approximately 200 Facebook fan pages concerning an anti-curriculum student movement. The experimental results show that Frame Dispatcher can classify microblogging data into frames efficiently and effectively.

Proceedings of the 2021 International Conference on Multimedia Retrieval, 2021

Figure 1: Some example RGB images (upper row) and the corresponding RF images (lower row), captur... more Figure 1: Some example RGB images (upper row) and the corresponding RF images (lower row), captured under different driving scenarios, used in the ROD2021 Challenge.

IEEE Access, 2017

In recent years, many researchers have examined dynamic optimization problems (DOPs). The key cha... more In recent years, many researchers have examined dynamic optimization problems (DOPs). The key challenge lies in the fact that the optimal solution of a DOP typically changes over time. This paper focuses on using query-based learning dynamic particle swarm optimization (QBLDPSO) to solve DOPs. QBLDPSO is mainly used for improving multi-population-based PSO; our QBL mechanism includes two learning strategies that integrate the concepts of diversity and memory into PSO. The first learning strategy, QBL quantum parameter adaptation (QBLQPA), is used to apply the concept of diversity to the multi-population based algorithm. This is different from typical diversity-based PSO approaches, which passively maintain the diversity of particles in the solution space. We actively adapt the ratio of quantum particles and neutral particles to achieve diversity without analyzing the distribution of optima in the solution space. The second learning strategy is query-based learning optima prediction (QBLOP). Although QBLOP exploits the concept of memory, we do not need to analyze the history of all particles. We select the k nearest particles to the current best solution and use a minimum encompassing circle as the possible prediction region. Our experimental results are based on the generalized dynamic benchmark generator (GDBG), which is adopted as a benchmark for the DOP. The proposed method outperforms two state-of-the-art multi-population-based PSO methods with the average improvements of 11.37% and 8% using QBLQPA. In particular, for the recurrent problems in GDBG, our method improves performance by 35.06%.

ECS Journal of Solid State Science and Technology, 2021

Journal of the American Ceramic Society, 2010

Highly efficient yttrium oxide doped with trivalent europium (Y2O3:Eu) phosphor was prepared thro... more Highly efficient yttrium oxide doped with trivalent europium (Y2O3:Eu) phosphor was prepared through precursors synthe-sized by hydrothermal method. Crystalline precursors, namely europium-doped yttrium carbonate (Y2(CO3)3 . 2H2O:Eu) and europium-doped yttrium ...

Journal of the American Ceramic Society, 2011

... Arunkumar Paulraj 1 ,; Prabu Natarajan 1 ,; Kottaisamy Munnisamy 2 ,; Mujafar Kani Nagoor 3 ,... more ... Arunkumar Paulraj 1 ,; Prabu Natarajan 1 ,; Kottaisamy Munnisamy 2 ,; Mujafar Kani Nagoor 3 ,; Kamaraj Parimana Nattar 1 ,; Burkanudeen Abdulrazak 3 ,; Jeyakumar Duraisamy 1,*. Article first published online: 27 APR 2011. DOI: 10.1111/j.1551-2916.2011.04535.x. ...

A graded nano-alloy of Au 100Àx Pt x (x ¼ 7, 15, 23, 32, 40, 51, 62, 73 and 86) nanoparticles (NP... more A graded nano-alloy of Au 100Àx Pt x (x ¼ 7, 15, 23, 32, 40, 51, 62, 73 and 86) nanoparticles (NPs) formed by co-reduction of HAuCl 4 and H 2 PtCl 6 and the details are presented in this work. Au 100Àx Pt x NPs were characterized using surface plasmon resonance (SPR) absorption spectroscopy and transmission electron microscopy (TEM). The NPs were dispersed in Vulcan carbon (Au 100Àx Pt x /C) and annealed at 250, 400, 600 and 800 C. The as-formed and annealed materials were characterized using TEM, high resolution transmission electron microscopy (HR-TEM), powder X-ray diffraction (XRD), cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS). The CV studies indicate excess Pt on the surface, which is corroborated by XPS and HR-TEM results. The XRD data show that Vegard's law is obeyed by the asformed material and the materials annealed at 250 and 400 C, indicating that these materials are not nano-alloys. The studies clearly indicate that the formation of Au 100Àx Pt x NPs is kinetically controlled rather than being controlled by the thermodynamic stability. The results demonstrate the formation of graded alloys of Au 100Àx Pt x NPs. Pt excess in the graded nano-alloy is reflected favourably in the electrochemical oxidation of small organics. In the methanol oxidation reaction (MOR), the peak current value per mg of Pt increases as a function of x, reaches a maximum value at x ¼ 23 and the ratio of forward current to reverse current for MOR reached an unprecedented value of 6.7, which shows the catalyst's stability against poisoning by carbonaceous intermediates.