Comparative Study of Shape Memory Alloy Reinforced Kevlar Polymer Composite in Sheet and Wire Form with Plain Kevlar Polymer Composite

R. Prabu,K. M. Kumar,R. Selvam,K. R. Vijaya Kumar 한국고분자학회 2021 폴리머 Vol.45 No.3

The main objective of this work is to investigate the effect of shape memory alloy reinforcement in Kevlar polymer composites on mechanical and low-velocity impact properties. The sheet and wire forms of shape memory alloy (SMA-nickel-titanium alloy) are used as potential reinforcements in Kevlar-reinforced polymer composite. The developed composites were analyzed for tensile and flexural behavior. The effective bonding area, referred to as core density, contributes to incremental flexural strength in the SMA sheet reinforced composites. The developed composites exhibited better impact resistance during low-velocity impact tests at different velocities, 2.80, 3.96, and 4.85 m/sec, and simulated using a CEAST drop hammer testing machine. The impact surface of the specimen was studied on a micro-level using SEM analysis and macro-level using Image J software. The impact force, the energy absorbed, and the deformation of the specimen during impact were recorded and analyzed. The experimental results reveal that the SMA sheet reinforced Kevlar composites exhibited appreciable impact resistance with maximum energy absorbing capacity comparatively with plain Kevlar and SMA wire reinforced composites.

Obtaining Weaker Form of Closed Sets in Topological Space using Python Program

M. Vivek Prabu,M. Rahini 한국수학교육학회 2022 純粹 및 應用數學 Vol.29 No.1

The impact of programming languages in the research sector has helped lot of researchers to broaden their view and extend their work without any limitation. More importantly, even the complex problems can be solved in no matter of time while converting them into a programming language. This convenience provides upper hand for the researchers as it places them in a comfort zone where they can work without much stress. With this context, we have converted the research problems in Topology into programming language with the help of Python. In this paper, we have developed a Python program to find the weaker form of closed sets namely alpha closed set, semi closed set, pre closed set, beta closed set and regular closed set.

Hierarchical nanostructured NiCo2O4 as an efficient bifunctional non-precious metal catalyst for rechargeable zinc-air batteries

Prabu, M.,Ketpang, K.,Shanmugam, S. Royal Society of Chemistry 2014 Nanoscale Vol.6 No.6

A nickel-doped cobalt oxide spinel structure is a promising non-precious metal electrocatalyst for oxygen evolution and oxygen reduction in rechargeable metal-air batteries and water electrolyzers operating with alkaline electrolytes. One dimensional NiCo2O4 (NCO) nanostructures were prepared by using a simple electrospinning technique with two different metal precursors (metal nitrate/PAN and metal acetylacetonate/PAN). The effect of precursor concentration on the morphologies was investigated. Single-phase, NCO with an average diameter of 100 nm, porous interconnected fibrous morphology was revealed by FESEM and FETEM analysis. The hierarchical nanostructured 1D-spinel NiCo2O4 materials showed a remarkable electrocatalytic activity towards oxygen reduction and evolution in an aqueous alkaline medium. The extraordinary bi-functional catalytic activity towards both ORR and OER was observed by the low over potential (0.84 V), which is better than that of noble metal catalysts [Pt/C (1.16 V), Ru/C (1.01 V) and Ir/C (0.92 V)], making them promising cathode materials for metal-air batteries. Furthermore, the rechargeable zinc-air battery with NCO-A(1) as a bifunctional electrocatalyst displays high activity and stability during battery discharge, charge, and cycling processes.

Effect of Ni and Si addition on electrical, tribological and corrosion behavior of novel Cu-Zn alloy

Saravanan. R,Suresh. P,Prabu. M,Bagyalakshmi. Pd 한양대학교 세라믹연구소 2022 Journal of Ceramic Processing Research Vol.23 No.4

The goal of this research is to evaluate the electrical, dry sliding wear and corrosion behaviour of copper-zinc alloy reinforcedwith Ni and Si through Powder Metallurgy (P/M) technique. Six different wt. % of novel copper-zinc alloy are considered forthis research study namely 90Cu-10Zn, 88.16Cu-10Zn-1.5Ni-0.34Si, 85Cu-15Zn, 83.16Cu-15Zn-1.5Ni-0.34Si, 80Cu-20Zn and78.16Cu-20Zn-1.5Ni-0.34Si. The fabricated composites were characterized by using Scanning Electron Microscope (SEM) withEnergy Dispersive Spectroscopy (EDS) line mapping. The electrical, wear and corrosion behaviour of the fabricatedcomposites was assessed. The hardness of the fabricated composites was evaluated using Vickers Hardness Tester. Theelectrical conductivity was assessed using four-point probe tester. The result shows a significant improvement on electrical andtribological properties by increasing the wt.% of Zn, Ni and Si led of the composites. The research results concludes that78.16Cu-20Zn-1.5Ni-0.34Si composite possessed better hardness about 287 HV and the electrical conductivity about 121%IACS. The investigation result shows that Zn acts as a vital role to enhance the properties in all aspects. Also, theexperimentation results portrays that Cu-20Zn-1.5Ni-0.34Si composite possessed better specific wear rate and coefficient offriction such as 1.85 * 105 mm3/N-m and 0.29 respectively.

Anti-inflammatory and analgesic activities of methanol extract of Triphala - a poly herbal formulation

Prabu, D.,Kirubanandan, S.,Ponnudurai, K.,Nappinnai, M.,Jinu, Alin J.S.,Renganathan, S. Kyung Hee Oriental Medicine Research Center 2008 Oriental pharmacy and experimental medicine Vol.8 No.4

Ayurveda, an ancient System of Indian Medicine, has recommended a number of drugs from indigenous plant sources for the treatment of inflammation. To evaluate the anti-inflammatory and analgesic activities of methanol extract of Triphala were investigated in Wister albino rats and mice. The methanol extract of Triphala were found to encompass substantial anti-inflammatory effect in acute and sub-acute models and analgesic effect. Animal models of carrageenan induced edema and cotton pellet induced granuloma in albino rats were used. Extract of 200 mg/kg shows significantly reduced paw edema. Analgesics activity of Triphala with 200 mg/kg shown by significant reduction of writhing. These report shows to support the use methanol extract of Triphala in relieving inflammation and pain.

A systematic approach to data-driven modeling and soft sensing in a full-scale plant

Kim, M. H.,Kim, Y. S.,Prabu, A. A.,Yoo, C. K. IWA Publishing 2009 Water Science & Technology Vol.60 No.2

<P>The well-known mathematical modeling and neural networks (NNs) methods have limitations to incorporate the key process characteristics at the wastewater treatment plants (WWTPs) which are complex, non-stationary, temporal correlation, and nonlinear systems. In this study, a systematic methodology of NNs modeling which can be efficiently included in the key modeling information of the WWTPs is performed by selecting the temporal effect of the hydraulics based on multi-way principal components analysis (MPCA). The proposed method is applied for modeling wastewater quality of a full-scale plant, which is a Daewoo nutrient removal (DNR) process. Through the experimental results in a full-scale plant, the efficiency of the proposed method is evaluated and the prediction capability is highly improved by the inclusion of the hydraulics term due to the optimized structure of neural networks.</P>

Anti-inflammatory and analgesic activities of methanol extract of Triphala - a poly herbal formulation

D. Prabu,S. Kirubanandan,K. Ponnudurai,M. Nappinnai,Alin J.S. Jinu,S. Renganathan 경희대학교 융합한의과학연구소 2008 Oriental Pharmacy and Experimental Medicine Vol.8 No.4

Ayurveda, an ancient System of Indian Medicine, has recommended a number of drugs from indigenous plant sources for the treatment of inflammation. To evaluate the anti-inflammatory and analgesic activities of methanol extract of Triphala were investigated in Wister albino rats and mice. The methanol extract of Triphala were found to encompass substantial anti-inflammatory effect in acute and sub-acute models and analgesic effect. Animal models of carrageenan induced edema and cotton pellet induced granuloma in albino rats were used. Extract of 200 mg/kg shows significantly reduced paw edema. Analgesics activity of Triphala with 200 mg/kg shown by significant reduction of writhing. These report shows to support the use methanol extract of Triphala in relieving inflammation and pain. Ayurveda, an ancient System of Indian Medicine, has recommended a number of drugs from indigenous plant sources for the treatment of inflammation. To evaluate the anti-inflammatory and analgesic activities of methanol extract of Triphala were investigated in Wister albino rats and mice. The methanol extract of Triphala were found to encompass substantial anti-inflammatory effect in acute and sub-acute models and analgesic effect. Animal models of carrageenan induced edema and cotton pellet induced granuloma in albino rats were used. Extract of 200 mg/kg shows significantly reduced paw edema. Analgesics activity of Triphala with 200 mg/kg shown by significant reduction of writhing. These report shows to support the use methanol extract of Triphala in relieving inflammation and pain.

Hyperbranched polyester as a crosslinker in polyurethane formation: real-time monitoring using in situ FTIR

Dhevi, D. M.,Anand Prabu, A.,Kim, K. J. Springer Science + Business Media 2016 Polymer bulletin Vol.73 No.10

<P>Hyperbranched polymers find applications in many fields such as biomedical, catalysis, commercial coatings, etc., owing to their many advantages such as ease of synthesis, more number of end functional groups, and low solution/melt viscosity. In our study, a previously unreported synthesis of A(2) + AB(2) type hyperbranched polyester (HBP) of three different generations (HBP-G1 to HBP-G3) using phenyl dichlorophosphate as a core and 2,2-dimethylol propionic acid as a monomer was carried out, and characterized using spectral, physical and thermal analyses. In situ FTIR was used to study the one-shot curing reaction between hexamethylene diisocyanate, polyethylene glycol and HBP-G3 at 60 A degrees C for two different NCO/OH ratios (1.2316 and 2.1042). Lower NCO/OH ratio (1.2316) was found to obey the second order, thereby indicating the occurrence of primary reaction between -OH and -NCO groups, whereas higher NCO/OH ratio (2.1042) follows third order due to auto-catalytic effect of urethane resulting from its reaction with excess isocyanate group. Non-isothermal curing kinetics of PU formation using in situ FTIR was accomplished to determine the percentage of urethane content formed using Factor Analysis program for the first time. Based on the above data, further curing kinetics studies were carried out at three different isothermal (70, 90, and 110 A degrees C) temperatures for lower NCO/OH ratio sample to extract its thermodynamic parameters.</P>

FTIR studies on polymorphic control of PVDF ultrathin films by heat-controlled spin coater

Dhevi, D. M.,Prabu, A. A.,Kim, K. J. Springer Science + Business Media 2016 JOURNAL OF MATERIALS SCIENCE - Vol.51 No.7

<P>The performance of organic polymer-based memory devices based on polyvinylidene fluoride (PVDF) ultrathin films depends on the extent of its ferroelectric crystalline phase content. In the present study, the changes in polymorphs of PVDF ultrathin films prepared by using heat-controlled spin coater are examined. The polymorphic changes were analyzed by using FTIR-transmission (TS) and FTIR-grazing incidence reflection-absorption spectroscopy (GIRAS) as a function of varying (i) spin-coating temperatures (SCT-30 to 80 A degrees C), (ii) spin-coating substrates (KBr, ITO and Gold) and (iii) thermal treatments [as-cast (AC) at 30 A degrees C, annealed at 130 A degrees C (AN130) and melt (200 A degrees C)-slow cooled (MSC)] conditions. Compared to MSC samples, the AC and AN130 samples exhibited higher beta-crystalline (polar, all-trans) phase along with the complete absence of alpha-crystalline (non-polar, tgtg') phase at lower SCT-30 and 40 A degrees C irrespective of the substrates used, thereby avoiding the need of high-temperature SCT conditions. Among the three substrates used, FTIR-GIRAS data obtained using ITO and Gold substrates were more favored than the FTIR-TS data obtained using KBr window due to their real-time usage as the substrate for electronic applications.</P>

Effects of hafnium on the structural, optical and ferroelectric properties of sol–gel synthesized barium titanate ceramics

Fernandez Jude,Bindhu B.,Prabu M.,Sandhya K. Y. 한국세라믹학회 2022 한국세라믹학회지 Vol.59 No.2

For future electronic devices, barium titanate based multifunctional ceramics falling under the category of ABO 3 perovskite type rose to prominence among scientists and engineers around the world. Moreover, the remarkable properties can be tuned by a strategy known as doping. The synthesis of hafnium (Hf 4+ ) doped BaHf x Ti (1- x ) O 3 , x = 0.00, 0.05, 0.10, 0.15 ceramics based on a wet chemical technique known as sol–gel, where the total time and temperature required for complete phase for- mation is considerably less, is reported in this article. The formation of a well-defined crystal structure with tetragonal phase showing P4mm space group was confirmed for BaHf x Ti (1- x ) O 3 ceramics calcined at 1000 °C using Raman spectroscopy and X-ray diff raction (XRD). The calcined powders consisting of grains with polyhedral shapes possessed particle sizes ranging from 160 to 460 nm. A signifi cant peak corresponding to metal oxide formation was obtained at 565  cm −1 for all the composi- tions in Fourier transform infrared (FTIR) spectra, proving the existence of the required perovskite phase. A minor variation in band gap energy with increase in Hafnium (Hf 4+ ) was found out using Ultraviolet–Visible-near-IR (UV–Visible-NIR) spectroscopy. Photoluminescence (PL) spectrum analysis, put forward the possibility of slight disorders in the ceramics; nonetheless, the spectra were found to be composed of peaks corresponding to blue, red and green emissions. The remnant polarization ( P r ), saturation polarization ( P s ) and coercive electric field ( E c ) of BaHf x Ti (1- x ) O 3 , calculated from ferroelectric hysteresis loop were found to vary appreciably with corresponding rise in hafnium (Hf 4+ ) concentration.