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Strength and durability studies on high strength concrete using ceramic waste powder
B. Karthikeyan,G. Dhinakaran 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.61 No.2
This paper summarizes the study on effect of ceramic waste powder as partial substitute to cement in binary blend and along with silica fume in ternary blend high strength concrete in normal and aggressive environments. Strength parameters such as compression & tension and durability indices such as corrosion measurement, deterioration, water absorption and porosity were studied. Ceramic waste powder was used in three different percentages namely 5, 10 and 15 with constant percentage of silica fume (1%) as substitutes to cement in ternary blend high strength concrete was investigated. After a detailed investigation, it was understood that concrete with 15% ceramic waste powder registered maximum performance. Increase of ceramic waste powder offered better resistance to deterioration of concrete.
Optimization of Drilling Characteristics for AI/SiC_p Composites Using Fuzzy/GA
Karthikeyan, R.,Jaiganesh, S.,Pai, B. C. 대한금속학회 2002 METALS AND MATERIALS International Vol.8 No.2
In this paper an attempt has been made to optimize the drilling characteristics for Al/SiCp composites using fuzzy logic and genetic algorithms (GA). The drilling characteristics studied were drill wear, specific energy and surface roughness. The parameters considered for the study include volume fraction of SiC in the aluminium matrix, cutting speed and feed rate. The experimental data was trained and simulated using fuzzy logic and optimization of cutting conditions were performed using genetic algorithms. The optimized cutting conditions were validated using confirmation experiments.
B. Balamugundan,L. Karthikeyan,M. Puviyarasan 한국고분자학회 2018 폴리머 Vol.42 No.1
Polymer nanocomposites are being increasingly used in a variety of tribological applications owing to their structural features. In this study, high density polyethylene (HDPE) composites with three different nanoparticles such as alumina (Al₂O₃), multi-walled carbon nanotubes (MWCNT) and graphene were fabricated using a newly designed friction stir processing tool and fixture. Mechanical test results showed that the fabricated polymer nanocomposites possess enhanced mechanical properties at higher tool rotational speed and traverse feed. The frictional coefficient and wear properties of the fabricated polymer nanocomposites were evaluated under dry sliding conditions using a pin-on-disc tribometer. Further the surfaces of the fabricated samples before and after wear studies were evaluated using scanning electron microscope. The wear test results showed that the HDPE/MWCNT has a very low mass loss as compared with HDPE/graphene, HDPE/Al₂O₃ composites and HDPE parent material. Moreover MWCNT particles act as a lubricant during wear test causing the worn surface of HDPE/MWCNT nanocomposites to be smoother as compared to other fabricated nanocomposites. The higher reflection peak between 23.71o to 23.95° obtained using X-ray diffraction (XRD) for the HDPE nanocomposites fabricated with the nanoparticles MWCNT, Al₂O₃ and graphene reveal a uniform mixture of the polymer matrix with the nanoparticles. The XRD results also show that the addition of nanoparticles does not significantly alter the crystal structure of the HDPE matrix.
A high performance hybrid capacitor with Li2CoPO4F cathode and activated carbon anode
Karthikeyan, K.,Amaresh, S.,Kim, K. J.,Kim, S. H.,Chung, K. Y.,Cho, B. W.,Lee, Y. S. The Royal Society of Chemistry 2013 Nanoscale Vol.5 No.13
<P>For the first time, we report the possibility of utilizing Li2CoPO4F as a novel cathode material for hybrid capacitor applications. Li2CoPO4F powders were prepared by a conventional two-step solid state method. A hybrid cell was fabricated using Li2CoPO4F as the cathode along with activated carbon (AC) as the anode in 1 M LiPF6 dissolved in 1 : 1 EC/DMC electrolyte and its electrochemical properties were examined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and constant current charge-discharge (C-D) techniques. The Li2CoPO4F/AC cell is capable of delivering a discharge capacitance of 42 F g(-1) at 150 mA g(-1) current density within 0-3 V region having excellent coulombic efficiency of over 99% even after 1000 cycles. Furthermore, the Li2CoPO4F/AC cell exhibited excellent rate performance with an energy density of ~24 W h kg(-1) at 1100 mA g(-1) current and maintained about 92% of its initial value even after 30,000 C-D cycles. Electrochemical impedance spectroscopy was conducted to corroborate the results that were obtained and described.</P>
MODEL-BASED CONTROL OF AN ELECTROPNEUMATIC BRAKE SYSTEM FOR COMMERCIAL VEHICLES
P. KARTHIKEYAN,D. B. SONAWANE,S. C. SUBRAMANIAN 한국자동차공학회 2010 International journal of automotive technology Vol.11 No.4
A properly functioning brake system is critical for ensuring the safe operation of any vehicle on roadways. Commercial vehicles such as trucks, tractors-trailers and buses are equipped with an air brake system that uses compressed air as the energy transmitting medium. This paper presents a model-based control scheme for an electropneumatic brake system for use in commercial vehicles. A mathematical model for an electropneumatic brake system was developed and corroborated with experimental data. A control scheme was developed based on this model and was used to regulate the pressure of air inside the brake chamber according to a desired pressure trajectory. This control scheme was implemented on an experimental test bench, and its performance was studied for various values of the controller parameter. The control scheme was tested for various desired pressure trajectories reflecting actual brake operation.
Optimizing the Milling Characteristics of Al - SiC Particulate Composites
Raghukandan, K .,Karthikeyan, R .,Naagarazan, R . S .,Pai, B . C . 대한금속재료학회(대한금속학회) 2000 METALS AND MATERIALS International Vol.6 No.6
The present investigation focuses on the face milling characteristics of LM25Al -SiC particulate composites produced through stir casting. Experiments were conducted according to an L27 orthogonal array and mathematical models were developed for such machining characteristics as flank wear, specific energy and surface roughness whose adequacy was checked. The insignificant effects present in the models were eliminated using a t-test. Goal programming was employed to optimize the cutting conditions by considering such primary objectives as maximizing the metal removal rate and minimizing tool wear, specific energy and surface roughness.
Amaresh, S,Karthikeyan, K,Kim, K J,An, J Y,Cho, S J,Chung, K Y,Cho, B W,Nam, K W,Lee, Y S American Scientific Publishers 2014 Journal of Nanoscience and Nanotechnology Vol.14 No.10
<P>Lithium cobalt fluorophosphate (Li2CoPO4F) is a promising 5 V class cathode material for lithium secondary batteries. In this study, surface coating with ZrO2 improved the electrochemical activity of Li2CoPO4F with a maximum discharge capacity of 144 mA h g(-1). The effectiveness of ZrO2 coating was evaluated using aging analysis with a commercial electrolyte, i.e., 1 M LiPF6 in EC:DMC (1:1, v/v). The metal ion dissolution was reduced to 1/8th of that observed in the non-coated Li2CoPO4F. It was found that the thin coating layer had less or no contribution to the additional resistance for the cell, both at an open circuit potential and at a fully charged state; hence, the capacity of the cell was retained over cycling. Elevated temperature aging did not affect the intrinsic property of the coated Li2CoPO4F, as observed from the complete anodic and cathodic peaks from cyclic voltammetry studies after 30 days of storage at 50 degrees C. An increase in impedance was observed for aged cells, which could be due to the thick SEI layer formed during storage. The ZrO2 coating over Li2CoPO4F was crucial for the improved performance of electrode active material at higher operating potentials of up to 5.2 V.</P>
K. Palanikumar,B. Latha,V. S. Senthilkumar,R. Karthikeyan 대한금속·재료학회 2009 METALS AND MATERIALS International Vol.15 No.2
Optimization of cutting parameters is important to achieving high quality in the machining process, especially where more complex multiple performance optimization is required. The present investigation focuses on the multiple performance optimization on machining characteristics of glass fiber reinforced plastic (GFRP) composites. The cutting parameters used for the experiments, which were carried out according to Taguchi’s L27, 3-level orthogonal array, were cutting speed, feed and depth of cut. Statistical models based on secondorder polynomial equations were developed for the different responses. The Non-dominated Sorting Genetic Algorithm (NSGA-II) tool was used to optimize the cutting conditions, yielding a non-dominated solution set that is reported here. Optimization of cutting parameters is important to achieving high quality in the machining process, especially where more complex multiple performance optimization is required. The present investigation focuses on the multiple performance optimization on machining characteristics of glass fiber reinforced plastic (GFRP) composites. The cutting parameters used for the experiments, which were carried out according to Taguchi’s L27, 3-level orthogonal array, were cutting speed, feed and depth of cut. Statistical models based on secondorder polynomial equations were developed for the different responses. The Non-dominated Sorting Genetic Algorithm (NSGA-II) tool was used to optimize the cutting conditions, yielding a non-dominated solution set that is reported here.