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Zafar R.,Indian National Institute of Engineering | Zafar R.,Swami Keshvanand Institute of Technology | Salim M.,Malviya National Institute of Technology
IEEE Sensors Journal | Year: 2015

Surface plasmon (SP) modes possesses an intriguing feature of confining light beyond diffraction limit, which makes it very attractive for sensing applications. Here, we theoretically investigated an ultra compact SP sensor using metal-insulator-metal (MIM) waveguide geometry. MIM waveguide is coupled to a pair of stub resonators and both the stub resonators are loaded with a metallic nanoslit of silver. The stubs and the MIM waveguide are filled with liquid/gaseous material which is to be sensed. The Fano resonance, which is very sensitive to any change in refractive index of the material, is excited in the structure by breaking marginal symmetry. The structure is numerically simulated by the finite difference time-domain method (FDTD), and the result shows that the resonance wavelength has a linear relation with refractive index of the material under sensing. In the optimum design of the proposed sensor, the maximum sensitivity is obtained as high as S = 1060 nm/refractive index unit with a large value of figure of merit (FOM = 176.7) and an ultra narrow linewidth Δλ = 6 nm. Thus, the device is well suited for designing on-chip optical sensors. © 2015 IEEE.

Awasthi K.K.,University of Rajasthan | John P.J.,University of Rajasthan | Awasthi A.,Indian Institute of Technology Roorkee | Awasthi K.,Malviya National Institute of Technology
Micron | Year: 2013

In the present study, multi walled carbon nano tubes (MWCNTs) were synthesized using chemical vapour deposition (CVD) technique. Swiss albino mice were orally administered with single dose of 60 and 100. mg/kg body weight of purified and functionalized MWCNTs suspended in water. The mice were autopsied on 7, 14, 21 and 28 days post exposure. Liver was taken out and part of it fixed in Bouin's solution for histopathological examinations. The remaining part was immersed in cold saline, blotted dry, weighed quickly and homogenized in ice cold buffer. The activity of superoxide dismutase (SOD) and catalase (CAT) was immediately measured in the supernatant. The MWCNTs in liver led to pathological changes, including injury to macrophages, cellular swelling, unspecific inflammation, spot necrosis and blood coagulation. Estimation of SOD and CAT showed altered levels in the experimental groups as compared to controls. Therefore, MWCNTs from manufactured and combustion sources in the environment can have adverse effects on human health. © 2012 Elsevier Ltd.

Rana T.H.,The LNM Institute of Information Technology | Rana T.H.,Indian Institute of Technology Mandi | Kumar P.,Indian Institute of Technology Mandi | Kumar P.,University of Nebraska - Lincoln | And 3 more authors.
Journal of Applied Physics | Year: 2013

We report the structural behavior of nanoscale Titanium Dioxide (TiO 2) clusters as well as their magnetic properties by varying the cluster size with the help of ground state geometries. The clusters of atomic scale rutile (TiO2)n, where n 1-11, have been considered and geometrically stabilized through the Density Functional Theory as implemented in Vienna ab-initio Simulation Package. It is being observed that as the size of cluster increases from n 2 to 11, the total energy decreases. The results of formation energy reveal the fact that as the cluster grows, it moves towards the stability and it is observed that n 11 is the most stable structure. The stabilized clusters are different in geometries and co-ordination numbers. Finally, all the clusters have been investigated with self consistent treatment of spin orbit coupling for magnetism studies. The magnetic properties of free clusters depict oscillatory behavior for magnetic moment with respect to the cluster size. © 2013 American Institute of Physics.

Sharma S.,University of Rajasthan | Vyas R.,Malviya National Institute of Technology | Shrivastava S.,University of Rajasthan | Vijay Y.K.,University of Rajasthan
Physica B: Condensed Matter | Year: 2011

We report a study on the SHI induced modifications on structural and optical properties of ZnO/PMMA nanocomposite films. The ZnO nanoparticles were synthesized by the chemical route using 2-mercaptoethanol as a capping agent. The structure of ZnO nanoparticles was confirmed by XRD, SEM and TEM. These ZnO nanoparticles were dispersed in the PMMA matrix to form ZnO/PMMA nanocomposite films by the solution cast method. These ZnO/PMMA nanocomposite films were then irradiated by swift heavy ion irradiation (Ni 8 ion beam, 100 MeV) at a fluence of 1×10 11 ions/cm 2. The nanocomposite films were then characterized by XRD, UVvis absorption spectroscopy and photoluminescence spectroscopy. As revealed from the absorption spectra, absorption edge is not changed by the irradiation but the optical absorption is increased. Enhanced green luminescence at about 527 nm and a less intense blue emission peak around 460 nm were observed after irradiation with respect to the pristine ZnO/PMMA nanocomposite film. © 2011 Elsevier B.V. All rights reserved.

Kumawat R.,Malviya National Institute of Technology | Sahula V.,Malviya National Institute of Technology | Gaur M.S.,Indian National Institute of Engineering
Proceedings of IEEE International Conference on Circuit, Power and Computing Technologies, ICCPCT 2013 | Year: 2013

The continual downsizing of silicon technology to nanoscale has enabled the realization of ultra high density, low power chips. However, such devices are inherently unreliable, contingent and prone to soft transient errors. As the deterministic approaches fail to model their behavior, and estimate the effect of soft transient errors on nanoscale devices, many probabilistic approaches have been proposed in literatures. In this manuscript, a comparative study of many of these approaches is presented. A computational framework based on Markov Random Field, Probabilistic Transfer Matrices and Probabilistic Decision Diagram is developed using MATLAB for design and analysis of combinational circuits at nanoscale. It is observed that Bayesian Network and Probabilistic Decision Diagrams have least time complexity among these approaches. The Probabilistic Transfer Matrices and Markov Random Fields are difficult to scale as they require lot of memory and long simulation time. However, Probabilistic Transfer Matrices provide more accurate output error probability. © 2013 IEEE.

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