Growth and Characterization of Lithium Potassium Phthalate (LiKP) Single Crystals for Third Order Nonlinear Optical Applications

Sivakumar, B.,Raj, S. Gokul,Kumar, G. Ramesh,Mohan, R. Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

Single crystals of lithium potassium phthalate (LiKP) were successfully grown from aqueous solution by solvent evaporation technique. The grown crystals were characterized by single crystal X-ray diffraction. The lithium potassium phthalate $C_{16}\;H_{12}\;K\;Li_3\;O_{11}$ belongs to triclinic system with the following unit-cell dimensions at 298(2) K;$a=7.405(5){\AA}$;$b=9.878(5){\AA}$;$c=13.396(5){\AA}$;${\alpha}=71.778(5)^{\circ}$;${\beta}=87.300(5)^{\circ}$;${\gamma}=85.405(5)^{\circ}$; having a space group P1. Mass spectrometric analysis provides the molecular weight of the compound and possible ways of fragmentations occurs in the compound. Thermal stability of the crystal was also studied by both simultaneous TGA/DTA analyses. The UV-Vis-NIR spectrum shows a good transparency in the whole of Visible and as well as in the near IR range. Third order nonlinear optical studies have also been studied by Z-scan technique. Nonlinear absorption and nonlinear refractive index were found out and the third order bulk susceptibility of compound was also estimated. The results have been discussed in detail.

Growth and Characterization of Lithium Potassium Phthalate (LiKP) Single Crystals for Third Order Nonlinear Optical Applications

B. Sivakumar,S. Gokul Raj,G. Ramesh Kumar,R. Mohan 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

Single crystals of lithium potassium phthalate (LiKP) were successfully grown from aqueous solution by solvent evaporation technique. The grown crystals were characterized by single crystal X-ray diffraction. The lithium potassium phthalate C16 H12 K Li3 O11 belongs to triclinic system with the following unit-cell dimensions at 298(2) K; a = 7.405(5) Å; b = 9.878(5) Å; c = 13.396(5) Å; α = 71.778(5)°; β = 87.300(5)°; γ = 85.405(5)°; having a space group P1. Mass spectrometric analysis provides the molecular weight of the compound and possible ways of fragmentations occurs in the compound. Thermal stability of the crystal was also studied by both simultaneous TGA/DTA analyses. The UV-Vis-NIR spectrum shows a good transparency in the whole of Visible and as well as in the near IR range. Third order nonlinear optical studies have also been studied by Z-scan technique. Nonlinear absorption and nonlinear refractive index were found out and the third order bulk susceptibility of compound was also estimated. The results have been discussed in detail.

Influence of combined radial location and growth on the leakage performance of a rotating labyrinth gas turbine seal

Sivakumar Subramanian,A. S. Sekhar,B. V. S. S. S. Prasad 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.6

Leakage characteristics, influenced by centrifugal and thermal radial growth are determined computationally for a generic rotating labyrinthseal used in the gas turbine secondary air system. Three seal locations, namely, R25, R50 and R75 are represented by means ofvarying the rotor radius mimicking different radial positions of the seal from the shaft axis. The combined influence of seal location andits radial (Centrifugal and thermal) growth on the leakage performance is investigated for a wide-ranging speeds from 1000 to 3000 rad/s,temperatures ranging from 200 to 450 oC and pressure ratios varying from 1.1 to 2.5, for a chosen initial clearance of 500 micron. Acomparison of the effect of rotation and temperature gradient among different rotors shows that the radial growth and leakage flow ratessignificantly vary with the increasing radius.

QR code as speckle pattern for reinforced concrete beams using digital image correlation

Krishna, B. Murali,Tezeswi, T.P.,Kumar, P. Rathish,Gopikrishna, K.,Sivakumar, M.V.N.,Shashi, M. Techno-Press 2019 Structural monitoring and maintenance Vol.6 No.1

Digital Image Correlation technique (DIC) is a non-contact optical method for rapid structural health monitoring of critical infrastructure. An innovative approach to DIC is presented using QR (Quick Response) code based random speckle pattern. Reinforced Cement Concrete (RCC) beams of size $1800mm{\times}150mm{\times}200mm$ are tested in flexure. DIC is used to extract Moment (M) - Curvature (${\kappa}$) relationships using random speckle patterns and QR code based random speckle patterns. The QR code based random speckle pattern is evaluated for 2D DIC measurements and the QR code speckle pattern performs satisfactorily in comparison with random speckle pattern when considered in the context of serving a dual purpose. Characteristics of QR code based random speckle pattern are quantified and its applicability to DIC is explored. The ultimate moment-curvature values computed from the QR code based random speckled pattern are found to be in good agreement with conventional measurements. QR code encrypts the structural information which enables integration with building information modelling (BIM).

Influence of coarse aggregate properties on specific fracture energy of steel fiber reinforced self compacting concrete

Raja Rajeshwari, B.,Sivakumar, M.V.N. Techno-Press 2020 Advances in concrete construction Vol.9 No.2

Fracture properties of concrete depend on the mix proportions of the ingredients, specimen shape and size, type of testing method used for the evaluation of fracture properties. Aggregates play a key role for changes in the fracture behaviour of concrete as they constitute about 60-75 % of the total volume of the concrete. The present study deals with the effect of size and quantity of coarse aggregate on the fracture behaviour of steel fibre reinforced self compacting concrete (SFRSCC). Lower coarse aggregate and higher fine aggregate content in SCC results in the stronger interfacial transition zone and a weaker stiffness of concrete compared to vibrated concrete. As the fracture properties depend on the aggregates quantity and size particularly in SCC, three nominal sizes (20 mm, 16 mm and 12.5 mm) and three coarse to fine aggregate proportions (50-50, 45-55, 40-60) were chosen as parameters. Wedge Split Test (WST), a stable test method was adopted to arrive the requisite properties. Specimens without and with guide notch were investigated. The results are indicative of increase in fracture energy with increase in coarse aggregate size and quantity. The splitting force was maximum for specimens with 12.5 mm size which is associated with a brittle failure in the pre-ultimate stage followed by a ductile failure due to the presence of steel fibres in the post-peak stage.

PERFORMANCE EVALUATION OF ON - SITE WASTE TREATMENT SYSTEMS USED BY REMOTE AND RURAL COMMUNITIES OF AUSTRALIA

( M . A . Khalife,H . B . Dharmappa,M . Sivakumar ) 한국물환경학회 1997 제6차 국제수질보전학회 아시아 태평양지역 학술회의 Vol.2 No.-

An investigation of the effects of a high valence state dopant (Zr4+) and the experimental insertion of two Na+ ions in the NaVOPO4 matrix

A Neelaveni,K Senthil,R Kalaivani,B Nalini,N Sivakumar 한국물리학회 2023 Current Applied Physics Vol.55 No.-

In this work, we attempt to incorporate two Na atoms into the NaVOPO4 matrix, which transforms the matrix into Na2VOPO4. To achieve this, we adjusted the phase parameters and used a facile synthesis method like the sol-gel-assisted hydrothermal technique. However, at high temperatures, the oxygen environment around the V atom changes, introducing the new phase Na2V(PO4)2 matrix into NaVOPO4. High valence state ions are required to support the active sites, keep the oxygen environment around them at a high temperature, and function well as a dopant for the NVP matrix. As a result, the Zr4+ is incorporated into the NVP matrix and it significantly enhances the tetragonal phases by enhancing (101), (112) planes. By substituting Zr4+ ion, the specific capacity of NVP is raised from 0.8268 mAh/g to 4.214 mAh/g at the scan rate of 10 mV/s.

Evaluation of reference genes for qRT-PCR studies in the colchicine producing Gloriosa superba L.

Johnson Nekha,Rodriguez Diaz Diana,Ganapathy Sivakumar,Bass John S.,Kutchan Toni M.,Khan Abdul L.,Flavier Albert B. 한국식물생명공학회 2023 Plant biotechnology reports Vol.17 No.4

The flame lily, Gloriosa superba L., is one of the two primary sources of the anti-inflammatory drug, colchicine. Previous studies have shown that a higher level of colchicine production occurs in the rhizomes than in leaves and roots. Earlier precursor feeding and transcriptome analysis of G. superba have provided a putative pathway and candidate genes involved in colchicine biosynthesis. Comparative analysis of expression levels of candidate pathway genes in different tissues of G. superba using quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) can reveal highly expressed genes in the rhizome compared to other tissues which could suggest roles of the gene products in colchicine biosynthesis. Normalization is an important step in effectively analyzing differential gene expression by qRT-PCR with broader applications. The current study selected candidate reference genes from the transcriptome datasets and analyzed them to determine the most stable genes for normalization of colchicine biosynthesis-related genes. Using RefFinder, one stable reference gene, UBC22, was selected to normalize gene expression levels of candidate methyltransferase (MT) genes in the leaves, roots, and rhizomes of G. superba. With UBC22 as reference gene, the methyltransferases, GsOMT1, GsOMT3, and GsOMT4 showed significantly higher expression levels in the rhizome of G. superba, while MT31794 was more highly expressed in the roots. In conclusion, the current results showed a viable reference gene expression analysis system that could help elucidate colchicine biosynthesis and its exploitation for increased production of the drug in G. superba.

Implementation of Deep Learning Techniques Based Artificial Intelligence for Healthcare Data Records

Rajagopal S.,Sundar Prakash Balaji M.,Sivakumar B.,Thenmozhi P. 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.5

Over the past ten years, there has been a signifi cant amount of study on the issue of healthcare services and technological innovation. To provide high-quality medical services in the remotes location, the IoT has established possible applicability in connecting the various healthcare devices, sensors, and medical personnel. This has increased operational effi ciency in the medical sector, reduced medical costs, enhanced access to the services of healthcare, and improved patients’ safety. To provide more standard service, a sizable portion of the Health Information Systems today consists of multiple independent systems that were previously built in the past but need to be combined. Despite being highly advanced technologically, the privacy of the medical information and communications network is a signifi cant obstacle to medical services. Unsupervised learning that is not stored in a repository may be diffi cult to manage and secure using conventional techniques. This paper presents a historical and contemporary analysis of Saudi Arabia's Medicare system with a focus on public safety and potential issues with data security and privacy. According to the same article's concept for national healthcare privacy using the IoT with AI-based systems, IoT-AI dashboards enable a tailored graphical interface for healthcare providers to preserve their data with key sources of data (IoT-AI). Even though most of the world uses these systems, there is still a need to fully understand them and the potential they off er. Medical data centres in Saudi Arabia have grown over the past few decades, and this research examines the signifi cance of service improvements in Saudi Arabia from several angles in order to better understand when the premium strategy might improve medical care and where it can be implemented. To better understand how diff erent specialties in medicine have communicated with medical systems over time, experts developed steps of the maturity paradigm.