Journal Articles
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/19884
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Item Advancement and challenges in MOSFET scaling(Elsevier Ltd, 2021) Ratnesh, R.K.; Goel, A.; Kaushik, G.; Garg, H.; Chandan, n.; Singh, M.; Prasad, B.In this study, we enlighten about the field effect transistors (FET) and their technologies. As far as very large integration is concerned, researchers are continuously focusing on scaling the transistors in a way to improve the transistors efficiency. In today's era, electronics and semiconductor industries are developing in such a manner that different nano scaled transistors work with low power as well as low cost designs. However, scaling of metal oxide semiconductor field effect transistor (MOSFET) into nanometer scale induces some effects like short channel effects, tunneling effects, and threshold voltage effects etc., which degrade the performance as well as cause challenges to the fabrication process. This review article deals not only with the limitations of scaling and ways to resolve them but also contains detailed study of silicon nanowire and other distinctive nano FET. Moreover, these research finding are helpful in directing the current advancements in MOSFET technology and gave a brief sketch of possible future technologies. © 2021Item Bed depth service time model for the biosorption of reactive red dye using the Portunus sanguinolentus shell(2010) JagadeeshBabu, P.E.; Krishnan, R.; Singh, M.Biosorption is an efficient and regenerative technique that often uses low-cost adsorbent materials, particularly for the treatment of wastewaters containing dyes and heavy metals. This study investigates the ability of crab shell (Portunus sanguinolentus) to remove reactive red dye in a packed bed up-flow column (internal diameter 2 cm; height 35 cm). Crab shell has high surface area (after proper size reduction) and high regenerative capacity. The experiments were performed with different bed heights (20 and 30 cm) and using different flow rates (12 and 17 ml/min) in order to obtain experimental breakthrough curves. The bed depth service time (BDST) model was used to analyze the experimental data and the model parameters were evaluated. The column regeneration studies were carried out for five different sorption-desorption cycles. The elutant used for the regeneration of the sorbent was 0.01 M EDTA (disodium) solution at pH 9.8 adjusted using NH4OH. This solution was found to have the best bed regeneration capacity and could be reused for several sorption-desorption cycles. The elution efficiency was greater than 99.1% in all seven cycles. Continuous use of the crab shell leads to a decrease in the adsorptive performance, as observed by the breakthrough curves becoming flatter and also because of a broader mass transfer zone. © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.Item Development of low temperature stoichiometric solution combustion derived transparent conductive ternary zinc tin co-doped indium oxide electrodes(Royal Society of Chemistry, 2017) Pujar, P.; Gandla, S.; Singh, M.; Gupta, B.; Tarafder, K.; Gupta, D.; Noh, Y.-Y.; Mandal, S.Here, the development of transparent conductive zinc tin co-doped indium oxide (IZTO: In1.4Sn0.3Zn0.3O3) ternary electrodes is addressed through low temperature solution combustion processing. Optimization of fuel to oxidizer ratio offers low temperature (?130 °C) of combustion with balanced redox reaction. The thin films of IZTO annealed at different temperatures showed a decreasing trend in the resistivity with a fixed order of 10-2 ? cm and the film with a highest Hall mobility of 5.92 cm2 V-1 s-1 resulted at 400 °C. All the films with different temperatures of annealing were smooth (rms ? 2.42 nm) in nature and the IZTO film annealed at 200 °C is 83% transparent in the visible spectra. The effective band gap of 0.9 eV determined from first-principles density functional theory gives clear evidence for the conducting nature of IZTO. The thin film transistor fabricated with IZTO as a gate electrode with poly(methyl methacrylate) and pentacene as the dielectric and channel material, respectively, exhibited a saturation mobility of 0.44 cm2 V-1 s-1 and Ion/Ioff ratio of 103. Further, the printability of the IZTO combustible precursor is established which resulted in anti-edge deposition of the printed feature. © 2017 The Royal Society of Chemistry.Item Statistical analysis of acoustic emissions generated during unconfined uniaxial compression of cementitious materials(Elsevier Ltd, 2019) Vidya Sagar, R.; Singh, M.; Deepak, S.; Desai, P.R.The article reports a study on the ‘goodness of fit’ of Weibull and Normal (Gaussian) distributions on the compressive strength and the corresponding Acoustic Emissions (AE) of cementitious materials. An attempt has been made to understand the variation of the parameters of the Weibull distribution and the Gaussian distribution carried out on the uniaxial compressive strength data and the corresponding recorded AE parameters. The statistical analysis of ‘Damage Parameter’ based on the peak amplitude of AE signals was also carried out. It was observed that the Weibull distribution was a better fit than Gaussian distribution for compressive strength and damage parameter. But in the case of AE parameters, Gaussian distribution was a better fit. The results obtained from this statistical study may be an addition to the existing knowledge on the statistical approach of AE associated with cementitious materials. A statistical approach may be suitable in predicting the data values without conducting further experiments. The results may be useful to understand the variation of physical properties such as homogeneity and ductility with the variation of compressive strength of cementitious materials and its corresponding AE parameters. © 2019Item Highly steerable microwave beamforming system near Ku band based on the application of linearly CFBG(Institution of Engineering and Technology jbristow@theiet.org, 2020) Raghuwanshi, S.K.; Srivastava, N.K.; Singh, M.In this study, the authors present theoretical and experimental results of wideband beamforming networks steered by a single linear chirped fibre Bragg grating (CFBG). The standard single-sideband modulation technique is followed to validate the wideband (at 18 GHz) operation of the proposed system. CFBG has been fabricated by phase mask technology for the desired specification to be compatible with the antenna array. To the authors knowledge, the effect of dispersion slope feature of fabricated FBG on the performance of beam-steering capability of the antenna is reported for the first time in this study. Theoretically preceded by experimental testing, it was found that the scanning angle increased with the rise in the number of antenna elements and the frequency of modulating microwave signal. © 2019 The Institution of Engineering and Technology.Item Simulation study of multilayer hybrid plasmonic switch using Franz-Keldysh effect(SPIE spie@spie.org, 2020) Sahu, S.K.; Khoja, R.; Kanu, S.; Kumar, A.; Singh, M.ACMOS compatible three-port all-optical silicon switch working in 1.473 to 1.502 ?m (extinction ratio (ER) = 5.5 dB, ?C = 1.488 ?m) and 1.512 to 1.5306 ?m (ER = 3.079 dB, ?C = 1.52 ?m) bands is demonstrated in this work through numerical simulations. However, in spite of the all optical control, having null refractive index contrast between the transmitting and control waveguides of the switch causes the switching merit to deteriorate because of light leaking from the transmitting waveguide. Later, by employing Franz Keldysh effect-induced absorption coefficient tuning of Si1-x Gex (x = 0.85) to replace the silicon control port of the switch, 2.95-dB leakage reduction in the ON state is achieved, which is assessed in detail. Also, our numerical simulations confirmed the bandwidth of 38 GHz, which suggested a multilayer plasmonic waveguide structure. © 2020 Society of Photo-Optical Instrumentation Engineers (SPIE).Item High-Resolution Fiber Optic Sensor based on Coated Linearly Chirped Bragg Grating(Elsevier GmbH, 2020) Singh, M.; Raghuwanshi, S.K.; Prakash, O.; Kumar, P.K.a fiber optic strain sensor is proposed and experimentally demonstrated using fiber Bragg grating (FBG) based interrogation scheme. Due to fast response time and better sensitivity of graphene oxide (GO) material, coated linearly chirped fiber Bragg grating (LCFBG) is used in this work. Interrogation scheme is used for the efficient strain sensing by placing LCFBG within the Sagnac loop (wavelength dependent receiver). The GO deposition is confirmed by ultraviolet–visible spectroscopy, atomic force microscopy (AFM), and field emission scanning electron micrograph (FESEM). Our proposed fiber optic strain sensor possesses better resolution, stable operation in the infra-red region. In addition, sensor demonstrates 5.25 ?? static strain and 0.645 ??/?Hz dynamic strain resolutions, respectively. © 2020 Elsevier GmbHItem Efficient Coherent Direction-of-Arrival Estimation and Realization Using Digital Signal Processor(Institute of Electrical and Electronics Engineers Inc., 2020) Dakulagi, V.; Alagirisamy, M.; Singh, M.A novel efficient coherent direction-of-arrival (DOA) estimation method is devised in this article. First, a new cost function without the knowledge of source number is developed exploiting the Toeplitz matrices' joint diagonalization structure. Then, the revised steering vectors are used in the place of projection weights of the steering vectors to reconstruct the power spectrum in both noise and signal subspaces. The coherent DOAs are estimated using the 1-D search. Furthermore, the computational complexity of the proposed method is significantly reduced using the Nystrom approximation. Finally, the developed theoretical model is implemented on the TMS320C6678 digital signal processor (DSP) to exemplify the efficacy of the novel method. © 1963-2012 IEEE.Item Reactive magnetron sputtered–assisted deposition of nanocomposite thin films with tuneable magnetic, electrical and interfacial properties(Springer Science and Business Media B.V. editorial@springerplus.com, 2020) Ratnesh, R.K.; Singh, M.; Pathak, S.; Dakulagi, V.In this work, different magnetic thin films of Ni, NiFe and NiFe2O4 are deposited on the SiO2 substrate using sputtering technique. Our experiments confirmed that thin films possess a good nanocrystalline structure. The key deposition parameters controlling their magnetic properties are sheet resistivity, crystalline structure and microtopography of the sputtered thin film. Besides, the reactive gas oxygen (O2) also plays a leading role in transforming the phase and structure of the ferrite film. The nanocrystalline nature of the ferrite film results in the reduction of overall coercivity (HC). The thickness of the sputtered thin film is in the range of 800–1000 Å. The prepared film exhibits roughness in the range of (~ 0.60 to ~ 0.98 nm). Furthermore, the structural transformation study is performed with X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The quite low roughness, high resistivity and low Hc make NiFe2O4 thin film as a potential candidate for the future spintronics, optoelectronics, photocatalysis and solar cell applications. © 2020, Springer Nature B.V.Item Study on co-seismic energy losses from hypocenter to ocean bottom for Sumatra earthquake 2004 using 3-D crustal deformation model(Springer Science and Business Media Deutschland GmbH info@springer-sbm.com, 2020) Sonker, M.K.; Devi, R.; Singh, M.; Chand, R.Our co-seismic GRACE gravity data (Level 2 ‘RL_05’ data product “GX-OG-_2-GSM) for Sumatra earthquake 2004 is obtained by differencing monthly gravity field average for November 2004 from that of January 2005 and band-pass filtering (17–30, degrees and orders) in spectral domain. Here we propose an 11-layered 3-D thrust fault gravity model based on several co-seismic rupture models in literature. Previously we have covered the 3-D modelling details and its inferences like slip rate, seismic moment, momentum etc. in our published literature. Further we extend the inferences through our model for this case study. Here, we have estimated the layer-wise energy distribution by undertaking two types energy loss one is spherical spreading and second absorption with constrained by literature. We have computed layer-wise energy loss, equivalent energy, differential pressure, slip rate, ultimate slip and work done. The computed differential pressure and work done for Sumatra Earthquake 2004 are 1.7552 × 108 N/m2 and 1.657 × 1018 J, respectively. We also estimated the absorption coefficient (calculated absorption coefficients) from our model to honour the slip rate of Sumatra earthquake 2004. The differential pressure is estimated for ocean bottom and sea level surface. The volumetric analysis is also provided for entire 3-D body (layer-wise) using excess mass of our model. The computed differential pressure indeed corresponds to an area pulse at ocean bottom that led to a Tsunami generation. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.