Synthesis and characterization of ZnGa2O4:Cr3+Ge3+ compounds with tunable photoluminescence properties

Kumar Pankaj,Sharma Aditya,Bishnoi Priyanka,Vij Ankush,Kumar Sandeep,Shin Hyun-Joon,Chae K. H.,Lee B. H.,Won S. O. 한국물리학회 2023 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.83 No.6

Pure and doped (Cr and Ge) ZnGa2O4 compounds are prepared using solid-state reaction method. Single-phase nature of pure and doped ZnGa2O4 compounds is investigated using X-ray difraction (XRD). XRD results indicate lower theta angle shifting, decrease in particle size and tensile strain in the doped samples. A granular morphology of amalgamated particles is seen in the SEM images. EDS results convey, practically, the same concentrations (atm%) of doped elements as used during the preparation. X-ray absorption near-edge structure (XANES) results helped to determine the valence state of elements. O K-edge XANES shows a signifcant orbital hybridization of O 2p shells with the d shells of doped atoms (i.e., Cr and Ge). Broad PL bands, of nearly the white-light emission, are observed in all of the samples. Modifcation in the PL intensity and emitted wavelengths, upon doping of Cr3+ and Ge3+ ions, are discussed through the energy transfer mechanisms and defects in the compounds.

Non-destructive evaluation of steel and GFRP reinforced beams using AE and DIC techniques

Gaurav Sharma,Shruti Sharma,Sandeep K. Sharma 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.77 No.5

The paper presents an investigation of the widely varying mechanical performance and behaviour of steel and Glass Fibre Reinforced Polymer (GFRP) reinforced concrete beams using non-destructive techniques of Acoustic Emission (AE) and Digital Image Correlation (DIC) under four-point bending. Laboratory experiments are performed on both differently reinforced concrete beams with 0.33%, 0.52% and 1.11% of tension reinforcement against balanced section. The results show that the ultimate load-carrying capacity increases with an increase in tensile reinforcement in both cases. In addition to that, AE waveform parameters of amplitude and number of AE hits successfully correlates and picks up the divergent mechanism of cracking initiation and progression of failure in steel reinforced and GFRP reinforced concrete beams. AE activity is about 20- 30% more in GFRP-RC beams as compared to steel-RC beams. It was primarily due to the lower modulus of elasticity of GFRP bars leading to much larger ductility and deflections as compared to steel-RC beams. Furthermore, AE XY event plots and longitudinal strain profiles using DIC gives an online and real-time visual display of progressive AE activity and strains respectively to efficaciously depict the crack evolution and their advancement in steel-RC and GFRP-RC beams which show a close matching with the micro-and macro-cracks visually observed in the actual beams at various stages of loading.

Moment-Curvature behavior of steel and GFRP reinforced beam using AE and DIC Techniques

Gaurav Sharma,Shruti Sharma,Sandeep K. Sharma 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.84 No.2

Using non-destructive Acoustic Emission (AE) and optical Digital Image Correlation (DIC) methods, the momentcurvature behavior of steel and GFRP bars reinforced concrete beams under flexure was explored in this study. In the tension zone, laboratory studies were carried out on steel-RC and GFRP-RC beams with varying percentages of longitudinal reinforcement ratios of 0.33 %, 0.52%, and 1.11%. The distinct mechanism of cracking initiation and fracture progression of failure in steel-RC and GFRP-RC beams were effectively correlated and picked up using AE waveform characteristics of the number of AE hits and their amplitudes, AE energy as well as average frequency and duration. AE XY event plots and longitudinal strain profiles using DIC gives an online and real-time visual display of progressive AE activity and strains respectively to efficaciously depict the crack evolution and their advancement in steel-RC and GFRP-RC beams. They display a close matching with the micro and macro-cracks visually observed in the actual beams at various stages of loading.

Microprocessor Based Multistandard Modem

Sandeep Gupta,Naresh Victor,Ashok K. Sharma,Ajit M. Karnik 대한전자공학회 1997 TENCON 87 - Computers and Communications Technolog Vol.- No.-

Hemihypertrophy with hypomelanosls of Ito

Hit K. Goswami,Aruna G. Rangnekar,Sandeep Sharma,Subodh Varshney,In Hwan Lee,Sung Ik Chang 대한의학유전학회 1998 대한의학유전학회지 Vol.2 No.1

A female hemihypertrophy patient with hypomelanosis of Ito is presented as a rare case combining classical features of both the syndrome. Chromosomal profile has been based on longitudinal study of repeated lymphocyte cultures during 1984-1992. The propositus has exhibited chromosomal mosaicism both hypoploid (42 ± 1) and hyperploid (48 ± 2 chromosome) counts, but the major stem line presented 46XX chromosomes. Ring chromosome with simple and complex translocations with marker dots appear to be the major cytogenetic assemblage of this child to posses unequal left and right halves of the body. Each and every organ from toe to the head has grown up unequally and lately the patient had been exhibiting different dark and light shapes of melanin on the skin. We believe that the patient had inherited, through her mole parent, "a few" mutated loci on some chromosomes so as to generate different cell lines within the developing child. All sibs and the mother showed normal karyotype with no apparent aberration.

Hemihypertrophy with hypomelanosis of Ito: A new syndrome combination

Goswami, Hit K.,Rangnekar, Aruna G.,Sharma, Sandeep,Varshney, Subodh,Lee, In-Hwan,Chang, Sung-Ik Korean Society of Medical Genetics 1998 대한의학유전학회지 Vol.2 No.1

A female hemihypertrophy patient with hypomelanosis of Ito is presented as a rare case combining classical features of both the syndrome. Chromosomal profile has been based on longitudinal study of repeated lymphocyte cultures during 1984-1992. The propositus has exhibited chromosomal mosaicism both hypoploid ($42{\pm}1$) and hyperploid ($48{\pm}2$ chromosome) counts, but the major stem line presented 46XX chromosomes. Ring chromosome with simple and complex translocations with marker dots appear to be the major cytogenetic assemblage of this child to posses unequal left and right halves of the body. Each and every organ from toe to the head has grown up unequally and lately the patient had been exhibiting different dark and light shapes of melanin on the skin. We believe that the patient had inherited, through her male parent, "a few" mutated loci on some chromosomes so as to generate different cell lines within the developing child. All sibs and the mother showed normal karyotype with no apparent aberration.

An Improved Approach to Ranking Web Documents

Pooja Gupta,Sandeep K. Singh,Divakar Yadav,A. K. Sharma 한국정보처리학회 2013 Journal of information processing systems Vol.9 No.2

Ranking thousands of web documents so that they are matched in response to a user query is really a challenging task. For this purpose, search engines use different ranking mechanisms on apparently related resultant web documents to decide the order in which documents should be displayed. Existing ranking mechanisms decide on the order of a web page based on the amount and popularity of the links pointed to and emerging from it. Sometime search engines result in placing less relevant documents in the top positions in response to a user query. There is a strong need to improve the ranking strategy. In this paper, a novel ranking mechanism is being proposed to rank the web documents that consider both the HTML structure of a page and the contextual senses of keywords that are present within it and its back-links. The approach has been tested on data sets of URLs and on their back-links in relation to different topics. The experimental result shows that the overall search results, in response to user queries, are improved. The ordering of the links that have been obtained is compared with the ordering that has been done by using the page rank score. The results obtained thereafter shows that the proposed mechanism contextually puts more related web pages in the top order, as compared to the page rank score

An Improved Approach to Ranking Web Documents

Poo A Gupta,Sandeep K. Singh,Divakar Yadav,A. K. Sharma 한국정보처리학회 2013 Journal of information processing systems Vol.9 No.2

An Improved Approach to Ranking Web Documents

Gupta, Pooja,Singh, Sandeep K.,Yadav, Divakar,Sharma, A.K. Korea Information Processing Society 2013 Journal of information processing systems Vol.9 No.2

Ranking thousands of web documents so that they are matched in response to a user query is really a challenging task. For this purpose, search engines use different ranking mechanisms on apparently related resultant web documents to decide the order in which documents should be displayed. Existing ranking mechanisms decide on the order of a web page based on the amount and popularity of the links pointed to and emerging from it. Sometime search engines result in placing less relevant documents in the top positions in response to a user query. There is a strong need to improve the ranking strategy. In this paper, a novel ranking mechanism is being proposed to rank the web documents that consider both the HTML structure of a page and the contextual senses of keywords that are present within it and its back-links. The approach has been tested on data sets of URLs and on their back-links in relation to different topics. The experimental result shows that the overall search results, in response to user queries, are improved. The ordering of the links that have been obtained is compared with the ordering that has been done by using the page rank score. The results obtained thereafter shows that the proposed mechanism contextually puts more related web pages in the top order, as compared to the page rank score.

Recent trends in biosensors

말호트라,Rahul Singhal,Asha Chaubey,Sandeep K. Sharma,Ashok Kumar 한국물리학회 2005 Current Applied Physics Vol.5 No.2

Rapid advances in biosensors have recently been reported. This has been possible due to rapid growth in the development of newbiomaterials such as conducting polymers, copolymers and sol gels etc and the reported improvements in sensing techniques. Bio-sensors are miniaturized devices employing biochemical molecular recognition as the basis for a selective analysis. The response gen-erated as a result of biochemical reaction is detected by a transducer to give a signal (optical/electrical/thermal) that can be used withor without amplication for the estimation of the concentration of an analyte in a given test sample. Among the various biosensors,electrochemical sensors, especially amperometric biosensors presently hold a leading position.Due to specicity, portability, simplicity, high sensitivity, potential ability for real-time and on-site analysis coupled with thespeed and low cost, biosensors have been projected to have applications in food analysis, environment control, clinical detection,drug and agriculture industries etc. Besides this, biosensors oer exciting opportunities for numerous decentralized clinical applica-tions, ranging from emergency room screening, home self testing and alternative site testing, continuous and real-time in vivo mon-itoring. New generation of biosensors combining new bioreceptors with the ever-growing number of transducers is emerging. Thepresent paper highlights some of the recent advances in the area of biosensors contributed by our laboratory..