Dr Brij Mohan - Academia.edu (original) (raw)

Papers by Dr Brij Mohan

An account of the work done at the Institute towards the development of a meteorological rocket p... more An account of the work done at the Institute towards the development of a meteorological rocket payload to measure the temperature and wind in the altitude range 70-20 km is presented. Circuit details, data deduction and its accuracy using microbead thermistor as sensor are described. Various temperature corrections due to aerodynamic heating, solar radiation, longwave radiation, conduction along the support

Electronic and magnetic properties of zigzag silicene nanoribbons with Stone-Wales defects J. App... more Electronic and magnetic properties of zigzag silicene nanoribbons with Stone-Wales defects J. Appl. Phys. 117, 064307 (2015); 10.1063/1.4907582 Electronic properties of graphene nano-flakes: Energy gap, permanent dipole, termination effect, and Raman spectroscopy J. Chem. Phys. 140, 074304 (2014); 10.1063/1.4865414

RSC Advances, 2014

ABSTRACT First principle calculations have been performed to study the geometric, electronic and ... more ABSTRACT First principle calculations have been performed to study the geometric, electronic and dielectric properties of low-buckled silicene with the adsorption of monomers, dimers and trimers of B, C and N atoms. Binding energy calculations show that all the adsorbates, except the homo N-N dimer, form a stable configuration on silicene. A band gap opening has been achieved for all the C adsorbates, homo dimers of B and N, the hetero N-B dimer and the B-C-N trimer on silicene. The plasmonic features and static dielectric constants are found to be tunable by various types of adsorbates on silicene which makes functionalized silicene a potential candidate for future nanoelectronics applications.

ABSTRACT First principle calculations have been performed to investigate the influence of mechani... more ABSTRACT First principle calculations have been performed to investigate the influence of mechanical strains on the electronic and dielectric properties of monolayer honeycomb structure of WS2. Our results reveal that mechanical strains reduce the band gap causing a direct-indirect band gap and semiconductor-metal transitions. These transitions, however, depends on the types of applied strain. Asymmetrical biaxial strain has been found to retain the identity of WS2 as a direct band gap semiconductor for 13% value of strain. Imaginary part of dielectric function(ɛ2) shows red-shift in the structure peak energy with applied strains. Static dielectric constant(ɛs) has been found to have significant dependence on the type of applied strain.

Physical Review B, 2004

The atomic and electronic structures of zirconia are calculated within density functional theory,... more The atomic and electronic structures of zirconia are calculated within density functional theory, and their evolution is analyzed as the crystal-field symmetry changes from tetrahedral (cubic (c-ZrO2) and tetragonal (t-ZrO2) phases) to octahedral (hypothetical rutile ZrO2), to a mixing of these symmetries (monoclinic phase, m-ZrO2). We find that the theoretical bulk modulus in c-ZrO2 is 30% larger than the experimental value, showing that the introduction of yttria in zirconia has a significant effect. Electronic structure fingerprints which characterize each phase from their electronic spectra are identified. We have carried out electron energy-loss spectroscopy experiments at low momentum transfer and compared these results to the theoretical spectra calculated within the random phase approximation. We show a dependence of the valence and 4p (N2,3 edge) plasmons on the crystal structure, the dependence of the latter being brought into the spectra by local-field effects. Lastly, we attribute low energy excitations observed in EELS of m-ZrO2 to defect states 2 eV above the top of the intrinsic valence band, and the EELS fundamental band gap value is reconciled with the 5.2 or 5.8 eV gaps determined by vacuum ultraviolet spectroscopy.

Physica E: Low-dimensional Systems and Nanostructures, 2012

Physica E: Low-dimensional Systems and Nanostructures, 2014

ABSTRACT The uni-axial and bi-axial mechanical strain mediated electronic band structures and die... more ABSTRACT The uni-axial and bi-axial mechanical strain mediated electronic band structures and dielectric properties of silicene have been investigated. It is found that on applying uni- and bi-axial strains, the band gap opens for smaller strain in silicene. However, on further increase of strain beyond 8% silicene changed into metal. The ultimate tensile strength estimated is 3.4 GPa. Imaginary part of dielectric function shows that the inter-band transitions are red-shifted for uni- and bi-axial tensile strains and are blue shifted for uni- and bi-axial compressive strains. Electron energy loss (EEL) function shows that the π+σ plasmon energies are red-shifted for uni- and bi-axial strains and blue-shifted for compressive strains. The π plasmons disappears for tensile and asymmetric strains. Bi-axial asymmetric strain is found to have no influence on inter-band transitions and π+σ plasmon energies.

Physica E: Low-dimensional Systems and Nanostructures, 2013

The buckling is enhancing in bilayer silicene as compared to monolayer silecene. Bilayer silicene... more The buckling is enhancing in bilayer silicene as compared to monolayer silecene. Bilayer silicene shows no plasmonic exciations for out-of-plane polarization below 5 eV.

Journal of Applied Meteorology, 1993

A tethersonde observational program was conducted for eight days during February and March 1989 a... more A tethersonde observational program was conducted for eight days during February and March 1989 at Pune (18[degrees]32'N, 73[degrees]51'E, 559 m MSL), India, during daytime for the study of mixed-layer evolution. A surface-based nocturnal inversion of intensity 8--10 K (100 m)[ ...

Indian Journal of Endocrinology and Metabolism, 2013

To assess the prevalence of persistent microalbuminuria (MAU), its clinical correlates by dip sti... more To assess the prevalence of persistent microalbuminuria (MAU), its clinical correlates by dip stick method, its predictive value for potential kidney disease and the utility of this test as objective cue for health care seeking behavior in adult Indian patients with type 2 diabetes mellitus. Approximately 400,000 patients shall be enrolled in this multicentric, cross sectional study. Patients meeting eligibility criteria shall be screened for MAU through urine dipstick test using random daytime single spot urine specimen. Result shall be expressed either positive or negative based on the presence or absence of albumin in the urine and will be correlated with the corresponding random blood glucose. Height, weight, waist circumference and blood pressure shall be assessed. There will be three visits with a minimum interval of 28 days between two visits, to be completed within 180 days, and at least two of three urine tests measured in this period must show elevated albumin levels to diagnose MAU. Detection of MAU through the dipstick method is postulated to be a rapid, reliable test for early detection of diabetic nephropathy, which, in turn will help the physician to plan treatment strategy. Further, it will help to identify the disease burden on the individual and society, and may serve as an objective cue for improved health care seeking behavior, as well as a catalyst for health policy change.

Chinese Physics Letters, 2006

Boundary-Layer …, 2003

Abstract. To understand and quantify the land-surface-vegetation interaction with the atmospheric... more Abstract. To understand and quantify the land-surface-vegetation interaction with the atmospheric boundary layer, and validate or improve upon the existing surface flux parameterization schemes in various weather forecast models, a LAnd Surface Processes EXperiment (LASPEX), ...

major complication (1/75, 1.3%): 1 case where the strings on the device broke. There were no leak... more major complication (1/75, 1.3%): 1 case where the strings on the device broke. There were no leaks at the GJ and no re-operations. There were no wound infections noted at the stapler introduction site. Conclusion: There is a significant learning curve associated with using the 25mm OrVil™ Device. During the 1st 25 procedures the major complication rate was 20% compared to 1.3% in the subsequent 75 cases(p ϭ 0.003). Intra-operative complications during the learning curve were not associated with post-operative complications. Surgeon experience may be a variable in this finding. The trans-oral approach does not increase the risk of wound infections.