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Search Results: 1 - 10 of 634 matches for " Ramasamy Gopalakrishnan "
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Compressive Strength and Electron Paramagnetic Resonance Studies on Waste Glass Admixtured Cement  [PDF]
Ramasamy Gopalakrishnan, Dharshnamoorthy Govindarajan
New Journal of Glass and Ceramics (NJGC) , 2011, DOI: 10.4236/njgc.2011.13017
Abstract: The present work reports the effect of waste glass (WG) on the properties of Portland cement through Electron Para- magnetic Resonance (EPR) study. Cement pastes containing 0, 10, and 30% replacement of waste glass with cement and in a water to cement ratio of 0.4 have been prepared. The g factors of Fe(III) and Mn(II) impurities at different hydration ages have been calculated. The decreased gFe values and simultaneous increase in gMn values with increase in replacement % of WG are explained due to retardation of cement hydration.
Comparative DFT Study of Phytochemical Constituents of the Fruits of Cucumis trigonus Roxb. and Cucumis sativus Linn.
Subarayan Bothi Gopalakrishnan,Thangaraj Kalaiarasi,Ramasamy Subramanian
Journal of Computational Methods in Physics , 2014, DOI: 10.1155/2014/623235
Abstract: The hepatoprotective active phytochemical constituents from the ethanolic extracts of the fruits of Cucumis trigonus Roxb. and Cucumis sativus Linn. were identified by GC-MS analysis. The density functional theory (DFT) of these molecules was calculated by density functional B3LYP methods using B3LYP/6-311++G(d,p) basis set. The optimized geometries of phytochemical constituents were evaluated. Physicochemical properties such as HOMO, LUMO, ionization potential, electron affinity, electronegativity, electrochemical potential, hardness, softness, electrophilicity, total energy, and dipole moment have also been recorded. These are very important parameters to understand the chemical reactivity and biological activity of the phytochemical constituents. Glycodeoxycholic acid and 2-(2-methylcyclohexylidene)-hydrazinecarboxamide were found to be effective drugs selected on the basis of their HOMO and LUMO energy gap and softness. The effective properties of these compounds may be due to the presence of amino, carbonyl, and alcohol as a functional group. 1. Introduction DFT is the connection between the density and the wave function which was developed by Hohenberg and Kohn and stated in the Hohenberg-Kohn theorems [1, 2]. The first theorem shows that the Hamiltonian is fully determined by the ground state density, which means that all the physical properties of the system are completely determined by the ground state density. The second theorem demonstrates that the energy functional can be used to find the ground state density. Importantly, the excited states need to be determined in a different way. During the last decade, computer simulations based on a quantum-mechanical description of the interaction between electrons and atomic nuclei have strongly influenced the development of material science [3]. The major advantage from a computational point of view is that the electronic density depends only on the three variables of space, while the wave function for an N electron system depends on 3N variables. DFT uses the B3LYP/6-311++G(d,p) hybrid functional in the gas phase. The presence of phytochemical constituents in the ethanolic extracts of the fruits of Cucumis trigonus and Cucumis sativus is responsible for curing liver disorder. Silymarin is used as a potential hepatoprotective agent. In the present work, a comparative DFT study of phytochemical constituents identified from the ethanolic extracts of the fruits of Cucumis trigonus and Cucumis sativus has been performed. Gaussian 09W program and Gauss-View molecular visualization program package on the
Comparison and Performance Analysis of FACTs Controller in System Stability  [PDF]
Karthikeyan Ramasamy
Circuits and Systems (CS) , 2016, DOI: 10.4236/cs.2016.710253
Abstract: In large inter connected power systems, inter-area oscillations are turned to be a severe problem. Hence inter-area oscillations cause severe problems like damage to generators, reduce the power transfer capability of transmission lines, increase wear and tear on network components, increase line losses etc. This paper is to maintain the stability of system by damping inter-area oscillations. Implementation of new equipment consists of high power electronics based technologies such as FACTs and proper controller design has become an essential to provide better damping performance than Power System Stabilizer (PSS). With development of Wide Area Measurement System (WAMS), remote signals have become as feedback signals to design Wide Area Damping Controller (WADC) for FACTs devices. In this work, POD is applied to both SVC and SSSC. Simulation studies are carried out in Power System Analysis Toolbox (PSAT) environment to evaluate the effectiveness of the FACTs controller in a large area power system. Results show that extensive analysis of FACTs controller for improving stability of system.
Pyrazolo Derivatives as Potent Adenosine Receptor Antagonists: An Overview on the Structure-Activity Relationships
Siew Lee Cheong,Gopalakrishnan Venkatesan,Priyankar Paira,Ramasamy Jothibasu,Alexander Laurence Mandel,Stephanie Federico,Giampiero Spalluto,Giorgia Pastorin
International Journal of Medicinal Chemistry , 2011, DOI: 10.1155/2011/480652
Abstract: In the past few decades, medicinal chemistry research towards potent and selective antagonists of human adenosine receptors (namely, A1, A2A, A2B, and A3) has been evolving rapidly. These antagonists are deemed therapeutically beneficial in several pathological conditions including neurological and renal disorders, cancer, inflammation, and glaucoma. Up to this point, many classes of compounds have been successfully synthesized and identified as potent human adenosine receptor antagonists. In this paper, an overview of the structure-activity relationship (SAR) profiles of promising nonxanthine pyrazolo derivatives is reported and discussed. We have emphasized the SAR for some representative structures such as pyrazolo-[4,3-e]-1,2,4-triazolo-[1,5-c]pyrimidines; pyrazolo-[3,4-c] or -[4,3-c]quinolines; pyrazolo-[4,3-d]pyrimidinones; pyrazolo-[3,4-d]pyrimidines and pyrazolo-[1,5-a]pyridines. This overview not only clarifies the structural requirements deemed essential for affinity towards individual adenosine receptor subtypes, but it also sheds light on the rational design and optimization of existing structural templates to allow us to conceive new, more potent adenosine receptor antagonists. 1. Introduction Adenosine is an endogenous nucleoside that mediates a wide range of physiological responses through interaction with specific adenosine receptors (ARs), which are G-protein-coupled receptors (GPCRs) comprising the characteristic seven transmembrane domains connected by three extracellular and three intracellular loops. There are four basic types of ARs that have been cloned and pharmacologically characterized, namely, A1, A2A, A2B, and A3 ARs [1]. Each of these ARs is associated with its own distinct biochemical pathways. Typically, the activation of A1 and A3 receptors mediates adenylyl cyclase inhibition through an interaction with Gi protein, followed by a subsequent decrease in the level of cyclic adenosine monophosphate (cAMP); conversely, the A2A and A2B receptors stimulate the adenylyl cyclase activity via the Gs protein thereby increasing the level of cAMP [2]. In addition, other signaling pathways involving phospholipases C and D, and Ca2+ and mitogen-activated protein kinases (MAPK) have also been described [1]. Pharmacologically, the inhibition of A1 receptors has led to implications in the renal system disorders through regulation of diuresis and neurological disorders such as Alzheimer’s disease [3, 4]; on the other hand, A3 receptor antagonists are primarily related to the treatment of glaucoma, renal protection, inflammatory disorders
Literature Review on Network Design Problems in Closed Loop and Reverse Supply Chains  [PDF]
Muthusamy Aravendan, Ramasamy Panneerselvam
Intelligent Information Management (IIM) , 2014, DOI: 10.4236/iim.2014.63012
Abstract:

The productivity of an organization is very much affected by non-value adding activity like logistics, which moves the resources from suppliers to factory, raw materials/semi-finished items within the factory and finished goods from factory to customers via a designated distribution channel called as forward logistics. In some cases, parts of the products such as automobiles, computers, cameras, mobile phones, washing machines, refrigerators, garments, footwear and empty glass bottles of beverages, etc. will be brought back to the factories as a product recovery strategy through reverse logistics network which is integrated in a sustainable closed loop supply chain network. So, it is highly essential to optimize the movement of the items in the reverse logistics network. This paper gives a comprehensive review of literature of the design of networks for the reverse logistics as well as for the reverse logistics coupled with forward logistics. The contributions of the researchers are classified into nine categories based on the methods used to design the logistics network.

An Integrated Multi-Echelon Model for a Sustainable Closed Loop Supply Chain Network Design  [PDF]
Muthusamy Aravendan, Ramasamy Panneerselvam
Intelligent Information Management (IIM) , 2014, DOI: 10.4236/iim.2014.66025
Abstract: The integration of entire supply and value chain into a closed loop network is gaining more importance in recent times in order to ensure a business to be economically and environmentally sustainable with the changing trends in business and social environments, growing environmental consciousness in the society and government legislations to protect the environment as well as the business. In this context, this paper considers a multi-echelon closed loop supply chain network design with forward and reverse logistics components. An attempt has been made to develop a mixed integer non-linear programming model for this problem with different costs so that the sum of the total cost is minimized subject to different constraints pertaining to capacities of the entities of the system, demands of first customers and second customers. A generalized model is presented and then its application is illustrated using an example problem by solving the model using LINGO14. This model forms as a tool to compare future meta-heuristics to check the closeness of their solutions with corresponding optimal solutions.
Literature Review of Open Shop Scheduling Problems  [PDF]
Ellur Anand, Ramasamy Panneerselvam
Intelligent Information Management (IIM) , 2015, DOI: 10.4236/iim.2015.71004
Abstract: This paper discusses review of literature of open shop scheduling problems. First, the problem is classified as per different measures of performance, viz., minimization of makespan, minimization of sum of completion times of jobs, minimization of sum of weighted completion times of all jobs, minimization of total tardiness of all jobs, minimization of sum of weighted tardiness of all jobs, minimization of weighted sum of tardy jobs, and miscellaneous measures of the open shop scheduling problem. In each category, the literature is further classified based on approaches used and then the contributions of researchers in the respective categories are presented. Directions for future research are discussed in the end.
Hybrid Genetic Algorithm for Machine-Component Cell Formation  [PDF]
Murugaiyan Pachayappan, Ramasamy Panneerselvam
Intelligent Information Management (IIM) , 2015, DOI: 10.4236/iim.2015.73010
Abstract: This paper considers machine-component cell formation problem of cellular manufacturing system. Since this problem comes under combinatorial category, development of a meta-heuristic is a must. In this paper, a hybrid genetic algorithm is presented. Normally, in genetic algorithm, the initial population is generated by random assignment of genes in each of the chromosomes. In this paper, the initial population is created using ideal seed heuristic. The proposed algorithm is compared with four other algorithms using 28 problems from literature. Through a completed factorial experiment, it is observed that the proposed algorithm outperforms the other algorithms in terms of grouping efficiency as well as grouping efficacy.
A Novel Enzymatic Method for Preparation and Characterization of Collagen Film from Swim Bladder of Fish Rohu (Labeo rohita)  [PDF]
Ramasamy Sripriya, Ramadhar Kumar
Food and Nutrition Sciences (FNS) , 2015, DOI: 10.4236/fns.2015.615151
Abstract: A novel enzymatic method for extraction and preparation of fish collagen from swim bladder revealed the occurrence of α, β and γ bands with approximately 12.1 g/100g collagen corresponding to 89% of collagen and thus confirmed the nativity and purity of the fish collagen. FT-IR studies confirmed the retention of all three amide bands of I, II and III, and triple helixcity. UN-crosslinked and UV-crosslinked fish collagen membrane records a very high temperature of helix denaturation at 197℃ and 215℃, shrinkage temperature at 50℃ ± 3.2℃ and 62℃ ± 2.7℃ and tensile strength at 16.89 ± 2.5 and 120.02 ± 1.0 Kg/cm2 respectively. Fish collagen matrix promoted NIH 3T3 and L6 cellular growth and proliferation. The study indicates that availability of pure fish collagen could replace bovine collagen in tissue engineering applications.
Development and Comparison of Hybrid Genetic Algorithms for Network Design Problem in Closed Loop Supply Chain  [PDF]
Muthusamy Aravendan, Ramasamy Panneerselvam
Intelligent Information Management (IIM) , 2015, DOI: 10.4236/iim.2015.76025
Abstract: This paper presents four different hybrid genetic algorithms for network design problem in closed loop supply chain. They are compared using a complete factorial experiment with two factors, viz. problem size and algorithm. Based on the significance of the factor “algorithm”, the best algorithm is identified using Duncan’s multiple range test. Then it is compared with a mathematical model in terms of total cost. It is found that the best hybrid genetic algorithm identified gives results on par with the mathematical model in statistical terms. So, the best algorithm out of four algorithm proposed in this paper is proved to be superior to all other algorithms for all sizes of problems and its performance is equal to that of the mathematical model for small size and medium size problems.
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