Department of Physics

&ldquo;IIT Jodhpur is committed to impart quality education to facilitate the creation of qualified, competent and responsible human resources to meet the emerging technological challenges of the world. It is working towards creating an equitable learning platform that is positive, accessible and effective in the face of the modern societal and scientific advancements.

Flexibility in curriculum, in all its academic programs, encompassing elements of teaching, research, creativity, innovation and entrepreneurship is the most unique feature of IIT Jodhpur. The Department of Science and Technology (DST), under the National Mission on Cyber Physical Systems, has identified IIT Jodhpur as a Technology &amp; Innovation Hub in the area of Augmented Reality and Virtual Reality. The institute has also been nominated as the coordinator for the Jodhpur City and Knowledge Cluster by the Office of Principal Scientific Adviser, Government of India.

The sprawling 852-acre IIT Jodhpur campus is a majestic tribute to the deep-rooted diverse cultural heritage of the region. The campus is an architectural masterpiece, which is slated to become an international exemplar of sustainability with net-zero energy, and advanced water and waste management strategies.&rdquo;

IIT Jodhpur

Synthesis of supramolecular assemblies of organotellurium(IV) dithiocarbamates, formed through intramolecular Te⋯S secondary bonds, intermolecular Te⋯X (X = I, S) secondary bonds and C-H⋯O hydrogen bonds are described. The supramolecular assemblies containing diethyldithiocarbamate group may serve as possible "rescue agents". The third order nonlinear optical susceptibility of the organotellurium(IV) diethyldithiocarbamate C 4H 7(CH 3)Te[S 2CN(C 2H 5) 2] 2 (1) has been studied by degenerate four wave mixing technique using a picosecond laser. It is found to exhibit efficient third-order nonlinear optical susceptibility (χ (3)) of 7.21 × 10 -14 esu and second order hyperpolarizability (γ) of 4.88 × 10 -32 esu. © 2012 Elsevier B.V. All rights reserved.

World University root node

Inorganica Chimica Acta

Supramolecular assemblies of organotellurium(IV) dithiocarbamates and third order nonlinear optical susceptibility (χ (3)) of C 4H 7(CH 3)Te[S 2CN(C 2H 5) 2] 2

The investigation is focused on the effect of Cr incorporation for Co/Fe in (Co 0.5Fe 0.5) 78-xCr xSi 8B 14 (x=012) amorphous microwires of 110 μm diameter prepared by in-water quenching technique. The rise in crystallization onset T X1 with Cr addition revealed the elemental contribution against devitrification and a consequent thermal stability. Cr is unfavorable towards ferromagnetic ordering leading to a linear drop in Curie temperature T ca with its rise in concentration. The presence of low Cr content upto Cr-4 at.% has been effective in drastically improving the Giant magneto-impedance (GMI) property. Cr content in the range of 4≤X≤10 has low magnetostriction and maximum field sensitivity in the as-quenched state. The GMI properties are further improved after annealing treatment. High content of Cr&gt;10 is found to be deleterious towards GMI behavior and its consequent application as sensor material. © 2011 Elsevier B.V. All rights reserved.

Journal of Magnetism and Magnetic Materials

Structural and Giant Magneto-impedance properties of Cr-incorporated CoFeSiB amorphous microwires

Undoped and (0.5-5 at%) molybdenum-doped TiO2 nanoparticles were synthesized by a simple and scalable wet chemical method. The as-synthesized materials were characterized using Xray diffraction (XRD), atomic force microscopy (AFM), Raman spectroscopy, electron paramagnetic resistance (EPR), and ultraviolet-visible (UV-Vis) spectroscopy techniques. XRD studies showed the formation of crystalline anatase phase of undoped TiO2, whereas Mo-doped samples showed the formation of an amorphous phase. AFM studies showed the formation of spherical-shaped particles with a particle diameter of ~23 nm in all samples. The photochromic behavior of these materials was studied by making their films in alkyd resin. Films of these materials showed a reversible photochromic color change from beige to brown on exposure to UV light. The coloration and bleaching process was recorded using UV-Vis diffuse reflectance spectroscopy. The maximum color change was observed in 2 at%Mo+6-doped nano-TiO2. The photochromic mechanism of molybdenum-doped nano-TiO2 was also examined using EPR spectroscopy. © Taylor &amp; Francis Group, LLC.

International Journal of Green Nanotechnology: Biomedicine

Wet chemical synthesis of molybdenum-doped amorphous TiO2 nanoparticles and studies on their photochromic properties

We investigate the influence of the phase front curvature of an input light beam on the transverse localization of light, choosing an evanescently coupled disordered one-dimensional semi-infinite waveguide lattice as an example. Our numerical study reveals that a finite phase front curvature of the input beam does indeed play an important role and it could degrade the quality of light localization in a disordered dielectric structure. More specifically, a faster transition from the ballistic mode of beam propagation due to diffraction to a characteristic localized state is observed in the case of a continuous wave (CW) beam whose phase front is plane, as compared to one having a curved phase front. © 2012 IOP Publishing Ltd.

Fulltext

Journal of Optics (United Kingdom)

Transverse localization of light and its dependence on the phase front curvature of the input beam in a disordered optical waveguide lattice

In the scenario with Z-mediated flavor changing neutral current occurring at the tree level due to the addition of a vectorlike isosinglet down-type quark d′ to the SM particle spectrum, we perform a χ2 fit using the flavor physics data and obtain the best fit value along with errors of the tree level Zb̄s coupling, Usb. The fit indicates that the new physics coupling is constrained to be small: we obtain |Usb|≤3. 40×10-4 at 3σ. Still, this does allow for the possibility of new physics signals in some of the observables, such as semileptonic CP asymmetry in Bs decays. © 2012 American Physical Society.

Physical Review D - Particles, Fields, Gravitation and Cosmology

B→s decays in a model with Z-mediated flavor changing neutral current

In an effort to design efficient platform for siRNA delivery, we combine all atom classical and quantum simulations to study the binding of small interfering RNA (siRNA) by pristine single wall carbon nanotube (SWCNT). Our results show that siRNA strongly binds to SWCNT surface via unzipping its base-pairs and the propensity of unzipping increases with the increase in the diameter of the SWCNTs. The unzipping and subsequent wrapping events are initiated and driven by van der Waals interactions between the aromatic rings of siRNA nucleobases and the SWCNT surface. However, molecular dynamics (MD) simulations of double strand DNA (dsDNA) of the same sequence show that the dsDNA undergoes much less unzipping and wrapping on the SWCNT in the simulation time scale of 70 ns. This interesting difference is due to smaller interaction energy of thymidine of dsDNA with the SWCNT compared to that of uridine of siRNA, as calculated by dispersion corrected density functional theory (DFT) methods. After the optimal binding of siRNA to SWCNT, the complex is very stable which serves as one of the major mechanisms of siRNA delivery for biomedical applications. Since siRNA has to undergo unwinding process with the effect of RNA-induced silencing complex, our proposed delivery mechanism by SWCNT possesses potential advantages in achieving RNA interference. © 2012 American Institute of Physics.

Journal of Chemical Physics

Unzipping and binding of small interfering RNA with single walled carbon nanotube: A platform for small interfering RNA delivery

In this paper, a quartz coaxial dielectric-barrier-discharge tube operated at different gas pressures and frequencies has been studied. A sinusoidal voltage up to 2.4 kVp with frequencies 34.5 and 47.5 kHz has been applied to the discharge electrodes for the generation of microdischarges. The experimental results confirm the filamentary nature of discharges when operated at different pressures (300, 600, and 1000 mbar) and at different frequencies (34.5 and 47.5 kHz). The relative influence of the given pressures and applied voltage waveforms on the discharge parameters has been analyzed. An equivalent electrical circuit model representing the multipeak phenomenon in the discharge has been developed, which validates the characteristics of the filamentary behavior. A series of simulations has been carried out in order to obtain the internal discharge parameters including discharge impedance which is not measurable during the experimental process. A close agreement between the simulated and experimental results has been obtained. From the experimental results and equivalent electrical circuit model, the dynamic nature of equivalent capacitance has also been reported. © 1973-2012 IEEE.

IEEE Transactions on Plasma Science

Multiswitch equivalent electrical model to characterize coaxial DBD tube

This paper reports the spectroscopic analysis in volume discharge arrangement of a dielectric barrier discharge source in parallel plate geometry of a width of 2 mm. Helium is used as a working gas. The investigations are carried out using sinusoidal supply for the generation of discharges where two current pulses have been observed with different polarities in one period. The electron plasma density and temperature during the discharge have been estimated using the line-ratio technique from the observed visible neutral helium lines. To validate the results, a commercial particle-in-cell simulation code, OOPIC-Pro, has been used, which confirms filamentary as well as diffused discharges observed in the experiment. This code analysis also validates the estimated electron plasma density and temperature measurements at two different working pressures and at a fixed operating frequency. © 2012 IEEE.

Spectroscopic diagnostic of volume discharge arrangement of a DBD source and comparison with PIC simulation code

In this paper, the development of large volume double ring Penning plasma discharge source for efficient light emissions is reported. The developed Penning discharge source consists of two cylindrical end cathodes of stainless steel having radius 6 cm and a gap 5.5 cm between them, which are fitted in the top and bottom flanges of the vacuum chamber. Two stainless steel anode rings with thickness 0.4 cm and inner diameters 6.45 cm having separation 2 cm are kept at the discharge centre. Neodymium (Nd2Fe14B) permanent magnets are physically inserted behind the cathodes for producing nearly uniform magnetic field of ∼0.1 T at the center. Experiments and simulations have been performed for single and double anode ring configurations using helium gas discharge, which infer that double ring configuration gives better light emissions in the large volume Penning plasma discharge arrangement. The optical emission spectroscopy measurements are used to complement the observations. The spectral line-ratio technique is utilized to determine the electron plasma density. The estimated electron plasma density in double ring plasma configuration is ∼2 × 1011 cm-3, which is around one order of magnitude larger than that of single ring arrangement. © 2012 American Institute of Physics.

Review of Scientific Instruments

Development of large volume double ring penning plasma discharge source for efficient light emissions

In this paper, the on-body performance of a light-weight and simple structure textile monopole antenna was investigated by determining reflection coefficient and bandwidth characteristics at 2.45 GHz. ShieldIt Super with conductivity of 1:96 × 10 5 S/m, is used as a conductive textile. The investigation of textile monopole antenna is carried out in the vicinity of human body, simulated by using HUGO model in CST Microwave Studio software, defined at a 8 × 8 × 8mm 3 voxel resolution. The distance of the antenna placed on human shoulder was varying between 0 and 15 mm. The investigation was aimed to study the changes in textile antenna's characteristics in terms of frequency detuning, bandwidth and reflection coefficient characteristics when the antenna was placed on the human body. The result showed that the reflection coefficient values were improved by 70.8% with a gradual enhancement of downward frequency shift as the textile monopole was varying between 0 and 15 mm. The result also demonstrated that an improvement up to a maximum of 72.8% in bandwidth was obtained when the textile monopole was positioned in the range of 2 to 15mm away from the human shoulder.