Grafting of Glycidyl Methacrylate upon Coralline Hydroxyapatite in Conjugation with Demineralized Bone Matrix Using Redox Initiating System

Murugan, R.,Rao, K.Panduranga The Polymer Society of Korea 2003 Macromolecular Research Vol.11 No.1

Grafting of glycidyl methacrylate (GMA) upon coralline hydroxyapatite in conjugation with demineralized bone matrix (CHA-DBM) using equal molar ratio of potassium persulfate/sodium metabisulfite redox initiating system was investigated in aqueous medium. The optimum reaction condition was standardized by varying the concentrations of backbone, monomer, initiator, temperature and time. The results obtained imply that the percent grafting was found to increase initially and then decrease in most of the cases. The optimum temperature and time were found to be 50 $^{\circ}C$ and 180 min, respectively, to obtain higher grafting yield. Fourier transform infrared (FT-IR) spectroscopy and X-ray powder diffraction (XRD) method were employed for the proof of grafting. The FT-IR spectrum of grafted CHA-DBM showed epoxy groups at 905 and 853 $cm^{-1}$ / and ester carbonyl group at 1731 $cm^{-1}$ / of poly(glycidyl methacrylate) (PGMA) in addition to the characteristic absorptions of CHA-DBM, which provides evidence of the grafting. The XRD results clearly indicated that the crystallographic structure of the grafted CHA-DBM has not changed due to the grafting reaction. Further, no phase transformation was detected by the XRD analysis, which suggests that the PGMA is grafted only on the surface of CHA-DBM backbone. The grafted CHA-DBM will have better functionality because of their surface modification and hence they may be more useful in coupling of therapeutic agents through epoxy groups apart from being used as osteogenic material.

ON THE DOMINATION NUMBER OF A GRAPH AND ITS SQUARE GRAPH

Murugan, E.,Joseph, J. Paulraj The Kangwon-Kyungki Mathematical Society 2022 한국수학논문집 Vol.30 No.2

For a given graph G = (V, E), a dominating set is a subset V' of the vertex set V so that each vertex in V ＼ V' is adjacent to a vertex in V'. The minimum cardinality of a dominating set of G is called the domination number of G and is denoted by γ(G). For an integer k ≥ 1, the k-th power G^k of a graph G with V (G^k) = V (G) for which uv ∈ E(G^k) if and only if 1 ≤ d_G(u, v) ≤ k. Note that G² is the square graph of a graph G. In this paper, we obtain some tight bounds for the sum of the domination numbers of a graph and its square graph in terms of the order, order and size, and maximum degree of the graph G. Also, we characterize such extremal graphs.

Sand particle-Induced deterioration of thermal barrier coatings on gas turbine blades

Murugan, Muthuvel,Ghoshal, Anindya,Walock, Michael J.,Barnett, Blake B.,Pepi, Marc S.,Kerner, Kevin A. Techno-Press 2017 Advances in aircraft and spacecraft science Vol.4 No.1

Gas turbines operating in dusty or sandy environment polluted with micron-sized solid particles are highly prone to blade surface erosion damage in compressor stages and molten sand attack in the hot-sections of turbine stages. Commercial/Military fixed-wing aircraft engines and helicopter engines often have to operate over sandy terrains in the middle eastern countries or in volcanic zones; on the other hand gas turbines in marine applications are subjected to salt spray, while the coal-burning industrial power generation turbines are subjected to fly-ash. The presence of solid particles in the working fluid medium has an adverse effect on the durability of these engines as well as performance. Typical turbine blade damages include blade coating wear, sand glazing, Calcia-Magnesia-Alumina-Silicate (CMAS) attack, oxidation, plugged cooling holes, all of which can cause rapid performance deterioration including loss of aircraft. The focus of this research work is to simulate particle-surface kinetic interaction on typical turbomachinery material targets using non-linear dynamic impact analysis. The objective of this research is to understand the interfacial kinetic behaviors that can provide insights into the physics of particle interactions and to enable leap ahead technologies in material choices and to develop sand-phobic thermal barrier coatings for turbine blades. This paper outlines the research efforts at the U.S Army Research Laboratory to come up with novel turbine blade multifunctional protective coatings that are sand-phobic, sand impact wear resistant, as well as have very low thermal conductivity for improved performance of future gas turbine engines. The research scope includes development of protective coatings for both nickel-based super alloys and ceramic matrix composites.

Establishment of Structural Similitude for Elastic Models and Validation of Scaling Laws

Murugan Ramu,V. Prabhu Raja,P. R. Thyla 대한토목학회 2013 KSCE JOURNAL OF CIVIL ENGINEERING Vol.17 No.1

Scaled down models are widely used for experimental investigations on huge structures due to the limitation in the capacities of testing facilities, and, moreover, the experimentation on scaled models is less expensive. Also small scale models are often built with materials dissimilar to those of the prototype. However, only few studies have been carried out on the similitude laws for the prototype structures with small scale models built with a different material. In the present study, an attempt has been made to develop a scaling law for models to carry out the free vibration analysis of structures, based on the similitude requirement. The established scaling laws are validated analytically using simple test problems. The similitude relationship between the prototype and the model is validated with the aid of a case study using finite element analysis software.

A Pattern Matching Extended Compression Algorithm for DNA Sequences

Murugan., A,Punitha., K International Journal of Computer ScienceNetwork S 2021 International journal of computer science and netw Vol.21 No.8

DNA sequencing provides fundamental data in genomics, bioinformatics, biology and many other research areas. With the emergent evolution in DNA sequencing technology, a massive amount of genomic data is produced every day, mainly DNA sequences, craving for more storage and bandwidth. Unfortunately, managing, analyzing and specifically storing these large amounts of data become a major scientific challenge for bioinformatics. Those large volumes of data also require a fast transmission, effective storage, superior functionality and provision of quick access to any record. Data storage costs have a considerable proportion of total cost in the formation and analysis of DNA sequences. In particular, there is a need of highly control of disk storage capacity of DNA sequences but the standard compression techniques unsuccessful to compress these sequences. Several specialized techniques were introduced for this purpose. Therefore, to overcome all these above challenges, lossless compression techniques have become necessary. In this paper, it is described a new DNA compression mechanism of pattern matching extended Compression algorithm that read the input sequence as segments and find the matching pattern and store it in a permanent or temporary table based on number of bases. The remaining unmatched sequence is been converted into the binary form and then it is been grouped into binary bits i.e. of seven bits and gain these bits are been converted into an ASCII form. Finally, the proposed algorithm dynamically calculates the compression ratio. Thus the results show that pattern matching extended Compression algorithm outperforms cutting-edge compressors and proves its efficiency in terms of compression ratio regardless of the file size of the data.

An Efficient DNA Sequence Compression using Small Sequence Pattern Matching

Murugan., A,Punitha., K International Journal of Computer ScienceNetwork S 2021 International journal of computer science and netw Vol.21 No.8

Bioinformatics is formed with a blend of biology and informatics technologies and it employs the statistical methods and approaches for attending the concerning issues in the domains of nutrition, medical research and towards reviewing the living environment. The ceaseless growth of DNA sequencing technologies has resulted in the production of voluminous genomic data especially the DNA sequences thus calling out for increased storage and bandwidth. As of now, the bioinformatics confronts the major hurdle of management, interpretation and accurately preserving of this hefty information. Compression tends to be a beacon of hope towards resolving the aforementioned issues. Keeping the storage efficiently, a methodology has been recommended which for attending the same. In addition, there is introduction of a competent algorithm that aids in exact matching of small pattern. The DNA representation sequence is then implemented subsequently for determining 2 bases to 6 bases matching with the remaining input sequence. This process involves transforming of DNA sequence into an ASCII symbols in the first level and compress by using LZ77 compression method in the second level and after that form the grid variables with size 3 to hold the 100 characters. In the third level of compression, the compressed output is in the grid variables. Hence, the proposed algorithm S_Pattern DNA gives an average better compression ratio of 93% when compared to the existing compression algorithms for the datasets from the UCI repository.

Surface-Modified Ni-rich Li[Ni<SUB>0.8</SUB>Co<SUB>0.1</SUB>Mn<SUB>0.1</SUB>]O₂ Layered Cathode by Mixed Metal Oxide Coating for Lithium-Ion Battery

Murugan NANTHAGOPAL,P. SANTHOSHKUMAR,Nitheesha SHAJI,Chenrayan SENTHIL,Chang Woo LEE 대한환경공학회 2019 대한환경공학회 학술발표논문집 Vol.2019 No.-

Fibre Rupture Phenomenon in Rotor Spinning

Murugan, R.,Dasaradan, B.S.,Karnan, P.,Senthilkannan, M. Subramanian The Korean Fiber Society 2007 Fibers and polymers Vol.8 No.6

The present work relates to the occurrence of fibre rupture during fibre separation in rotor spinning and also discusses the mechanism of such rupture. The reduction in fibre length during opening has been studied at different span lengths. A correlation has been drawn showing the influence of combing roller action on yam tenacity and elongation. Fibre rupture has direct relationship with opening roller speed. Fibre rupture and surface damage occurring due to action of opening roller together are found to mar the yarn quality index.

An Evolutionary Optimized Algorithm Approach to Compensate the Non-linearity in Linear Variable Displacement Transducer Characteristics

Murugan, S.,Umayal, S.P. The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.6

Linearization of transducer characteristic plays a vital role in electronic instrumentation because all transducers have outputs nonlinearly related to the physical variables they sense. If the transducer output is nonlinear, it will produce a whole assortment of problems. Transducers rarely possess a perfectly linear transfer characteristic, but always have some degree of non-linearity over their range of operation. Attempts have been made by many researchers to increase the range of linearity of transducers. This paper presents a method to compensate nonlinearity of Linear Variable Displacement Transducer (LVDT) based on Extreme Learning Machine (ELM) method, Differential Evolution (DE) algorithm and Artificial Neural Network (ANN) trained by Genetic Algorithm (GA). Because of the mechanism structure, LVDT often exhibit inherent nonlinear input-output characteristics. The best approximation capability of optimized ANN technique is beneficial to this. The use of this proposed method is demonstrated through computer simulation with the experimental data of two different LVDTs. The results reveal that the proposed method compensated the presence of nonlinearity in the displacement transducer with very low training time, lowest Mean Square Error (MSE) value and better linearity. This research work involves less computational complexity and it behaves a good performance for nonlinearity compensation for LVDT and has good application prospect.

Analysis of Subthreshold Behavior of FinFET using Taurus

Murugan, Balasubramanian,Saha, Samar K.,Venkat, Rama The Institute of Electronics and Information Engin 2007 Journal of semiconductor technology and science Vol.7 No.1

This paper investigates the subthreshold behavior of Fin Field Effect Transistor (FinFET). The FinFET is considered to be an alternate MOSFET structure for the deep sub-micron regime, having excellent device characteristics. As the channel length decreases, the study of subthreshold behavior of the device becomes critically important for successful design and implementation of digital circuits. An accurate analysis of subthreshold behavior of FinFET was done by simulating the device in a 3D process and device simulator, Taurus. The subthreshold behavior of FinFET, was measured using a parameter called S-factor which was obtained from the $In(I_{DS})\;-\;V_{GS}$ characteristics. The value of S-factor of devices of various fin dimensions with channel length $L_g$ in the range of 20 nm - 50 nm and with the fin width $T_{fin}$ in the range of 10 nm - 40 nm was calculated. It was observed that for devices with longer channel lengths, the value of S-factor was close to the ideal value of 60 m V/dec. The S-factor increases exponentially for channel lengths, $L_g\;<\;1.5\;T_{fin}$. Further, for a constant $L_g$, the S factor was observed to increase with $T_{fin}$. An empirical relationship between S, $L_g$ and $T_{fin}$ was developed based on the simulation results, which could be used as a rule of thumb for determining the S-factor of devices.