المؤلفون: V. Vyas, Yamini Sharma, B. K. Sharma, V. Purvia, K.B. Joshi

المصدر: Pramana. 70:323-337

مصطلحات موضوعية: Momentum, Materials science, Covalent bond, Linear combination of atomic orbitals, Isotropy, General Physics and Astronomy, Condensed Matter::Strongly Correlated Electrons, Electronic structure, Crystallite, Atomic physics, Valence electron, Fermi Gamma-ray Space Telescope

الوصف: In this paper the results of a Compton profile study of two polycrystalline A15 compounds, namely, V3Ge and Cr3Ge, have been reported. The measurements have been performed using 59.54 keV γ-rays from an 241Am source. The theoretical Compton profiles have been computed for both the compounds using ab-initio linear combination of atomic orbitals (LCAO) method employing CRYSTAL98. For both the A15 compounds, the isotropic experimental profiles are found to be in good overall agreement with the calculations. The comparison points out residual differences in V3Ge whereas for Cr3Ge the differences are within experimental error. The behaviour of valence electrons in the two iso-structural compounds has been examined on the scale of Fermi momentum. The valence electron distribution seems to be dominated by the metallic constituents rather than Ge and two compounds show covalent nature of bonding which is larger in V3Ge compared to Cr3Ge.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::7dd773e37e568b0a1854becfb2205256Test
https://doi.org/10.1007/s12043-008-0051-yTest

المؤلفون: Yogesh K. Meghrajani, Yamini Sharma

المصدر: 2015 International Conference on Innovations in Information, Embedded and Communication Systems (ICIIECS).

مصطلحات موضوعية: medicine.diagnostic_test, Computer science, business.industry, Multiple sclerosis, Normal tissue, Automated segmentation, Magnetic resonance imaging, medicine.disease, Mri image, medicine, Computer vision, Manual segmentation, Artificial intelligence, business, Automated method

الوصف: This paper describes a statistical approach for segmenting multiple sclerosis lesions (tumors) from magnetic resonance imaging (MRI) images. Proposed method detects and segments the areas inside the brain that are affected by tumors. Tumor regions are the areas of higher intensity in comparison to normal tissue. Our automated method gives satisfactory results showing that the proposed method is capable of segmenting multiple sclerosis lesions of different shapes and intensities. In order to show the efficacy of proposed approach, experimental results are compared with the results of other algorithm and also with the results of manual segmentation performed by experts.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::6076764067e5ba5970f0083151ca5474Test
https://doi.org/10.1109/iciiecs.2015.7193144Test

المؤلفون: Ramesh Sharma, Yamini Sharma, Shalini Dwivedi

المصدر: AIP Conference Proceedings.

مصطلحات موضوعية: Superconductivity, Coupling constant, symbols.namesake, Materials science, Condensed matter physics, Lattice (order), Fermi level, symbols, Fermi surface, Electronic structure, Electron, Crystal structure

الوصف: We have studied the electronic, transport and vibrational properties of low temperature superconductor β-PdBi2. The band manifold clearly demonstrates the 2D-layered structure with multiple gaps. The intersection of bands at EF in the Γ-P, Γ-N directions gives rise to complicated Fermi surface topology, which contains quite complicated multiple connected sheets, as well as hole and electron-like pockets. From the low temperature specific heat, we have estimated the electron-phonon coupling constant λel-ph which has a very high value of 3.66. The vibrational properties clearly illustrates that the strong coupling makes the lattice unstable. The calculated properties confirm that β-PdBi2 is an intermediate coupling superconductor.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::081eeb794f58cb9e7898fd955118b288Test
https://doi.org/10.1063/1.4918151Test

المؤلفون: V. Vyas, Yamini Sharma, V. Purvia, K.B. Joshi, B. K. Sharma

المصدر: physica status solidi (b). 243:1253-1262

مصطلحات موضوعية: Pseudopotential, Crystallography, Ionic model, Spectrometer, Chemistry, Compton scattering, Gamma ray, Ionic bonding, Atomic physics, Condensed Matter Physics, Electronic, Optical and Magnetic Materials

الوصف: In this work we report on the Compton scattering study of ZnSe. The Am241 Compton spectrometer, which uses 59.54 keV gamma rays, has been used for the measurements. The data has been compared with the ionic model based calculations for various Zn+xSe–x configurations (x varying from 0 to 2) and also with the Compton profiles computed from the local and non-local empirical pseudopotential methods. Although, the agreement is better with the local empirical pseudopotential calculation compared to the non-local method, the best agreement has been found with the ionic model for Zn+2Se–2 configuration suggesting that the bonding in this compound is mainly ionic in nature. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::1db718d35e58124fe5f9f3dc3ca157a1Test
https://doi.org/10.1002/pssb.200541462Test

المؤلفون: Yamini Sharma, Yogesh K. Meghrajani

المصدر: 2014 2nd International Conference on Emerging Technology Trends in Electronics, Communication and Networking.

مصطلحات موضوعية: Computer science, business.industry, Tumor region, Brain tumor, Real-time MRI, medicine.disease, Impulse noise, Thresholding, Mri image, medicine, Computer vision, Brain magnetic resonance imaging, Artificial intelligence, Noise (video), business

الوصف: This paper describes an approach based on mathematical morphological reconstruction for extraction of a tumor from labeled brain magnetic resonance imaging (MRI) images affected by impulse noise. As a part of pre-processing, global thresholding technique is applied on the input MRI image. Afterward, mathematical morphological reconstruction operation segments a brain tumor from the processed image. Algorithm is further modified for non-uniform intensity regions of the brain tumor. Optionally, mathematical morphological operator is utilized to remove pepper noise if presents in tumor region. Finally, tumor region is extracted using resultant image and input MRI image. Experimental results show the proposed method effectively extracts a brain tumor from noisy labeled MRI images.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::a2a32e6416d0997950ee1199e9f615f4Test
https://doi.org/10.1109/et2ecn.2014.7044982Test

المؤلفون: Anirudh Thakur, Yamini Sharma, Harminder Pal Singh

المصدر: Indian Journal of Horticulture. 74:440

مصطلحات موضوعية: Plant density, 04 agricultural and veterinary sciences, Subtropics, Trellis (architecture), Horticulture, Espalier, 040401 food science, Hedge, Forensic science, 0404 agricultural biotechnology, Agronomy, Yield (wine), Crop quality, Mathematics

الوصف: Information on the use of different training systems in peach under the sub-tropics is inadequate. Trees of Shan-i-Punjab peach were planted at two spacings, viz., 5 m x 2 m and 5 m x 3 m and were trained to four training systems, viz., Y shaped, Hedge row, Espalier and V trellis. The fruits harvested from Espalier and V trellis trained trees were superior in fruit quality in terms of fruit size, weight, colour and TSS as compared to fruit harvested from other training systems. Fruit yield was found to be maximum from V trellis trained trees. Trees planted at 5 m x 3 m gave higher fruit yield and better quality fruits as compared to 5 m x 2 m planted trees irrespective of training systems.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::789315b6b3baaf805863d641683304caTest
https://doi.org/10.5958/0974-0112.2017.00085.8Test

المؤلفون: Ramesh Sharma, Shalini Dwivedi, Yamini Sharma, Seema Shukla

المصدر: AIP Conference Proceedings.

مصطلحات موضوعية: Absorption spectroscopy, Condensed matter physics, Hydrogen, Ab initio, chemistry.chemical_element, Yttrium, Molecular physics, Metal, Condensed Matter::Materials Science, chemistry, Transition metal, visual_art, visual_art.visual_art_medium, Density of states, Electronic band structure

الوصف: We have performed ab initio self consistent calculations based on Full potential linearized augmented plane wave (FP-LAPW) method to investigate the optical and thermal properties of yttrium hydrides. From the band structure and density of states, the optical absorption spectra and specific heats have been calculated. The band structure of Yttrium metal changes dramatically due to hybridization of Y sp orbitals with H s orbitals and there is a net charge transfer from metal to hydrogen site. The electrical resistivity and specific heats of yttrium hydrides are lowered but the thermal conductivity is slightly enhanced due to increase in scattering from hydrogen sites.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::f8d9ad35365d5ae5f2df351243012934Test
https://doi.org/10.1063/1.4872870Test

المؤلفون: Yamini Sharma, Chamma Tiwari, Ramesh Sharma

المصدر: AIP Conference Proceedings.

مصطلحات موضوعية: symbols.namesake, Materials science, Condensed matter physics, Ab initio quantum chemistry methods, Band gap, Fermi level, Ab initio, symbols, Fermi energy, Density functional theory, Electronic structure, Spin (physics)

الوصف: In this paper we perform spin polarized calculations and present the electronic structure of Fe doped MoX2 (X=S, Se, Te) using the density functional theory (DFT) with generalized gradient approximation (GGA). The calculated indirect band gaps for semiconducting MoS2, MoSe2 and MoTe2 are 0.788, 0.864 and 0.68 eV respectively. The dx2−y2 & dxy states hybridized with p and d states of S and Mo contribute to additional states in the vicinity of Fermi energy.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::cd5513a4d9c94678555e3524e32cca52Test
https://doi.org/10.1063/1.4791306Test

المؤلفون: Yamini Sharma, Pankaj Srivastava, Amitabha Ghoshray, Bilwadal Bandyopadhyay, Chandan Mazumdar

المصدر: AIP Conference Proceedings.

مصطلحات موضوعية: Physics, Linear combination of atomic orbitals, Astrophysics::High Energy Astrophysical Phenomena, Density of states, Density functional theory, Electronic structure, Electron, Atomic physics, Relativistic quantum chemistry, Electronic band structure, Spin-½

الوصف: The energy bands, density of states and Compton profile of Cr2S3 have been computed using band structure methods namely linear combination of atomic orbitals with density functional theory as well as by spin polarized relativistic Kronig–Kramer–Rostokar method. To analyze the theoretical data on electron momentum densities, the Compton profile of Cr2S3 has been measured using 100mCi 241Am Compton spectrometer. The isotropic profile satisfies the calculated profiles. The band structure calculations are also compared with the available data.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::957a11ddd8032dbaa1cf303b8626f7b6Test
https://doi.org/10.1063/1.3601801Test

المؤلفون: Pankaj Srivastava, Yamini Sharma, P. Predeep, Mrinal Thakur, M. K. Ravi Varma

المصدر: AIP Conference Proceedings.

مصطلحات موضوعية: Condensed Matter::Materials Science, Photoluminescence, Materials science, business.industry, Infrared, Thermoelectric effect, Plane wave, Optoelectronics, Density functional theory, Dielectric, Time-dependent density functional theory, Photoelectric effect, business

الوصف: Group III2‐VI3 materials have potential for use in the electronic industry for optoelectronic or photoelectric applications. The structural, electronic and optical properties of Ga2S3 and Ga2O3 are investigated using first‐principal calculations based on density functional theory (DFT) with the full potential linear augmented plane wave (FP‐LAPW) method. The calculated dielectric functions will be explained in terms of interband transitions in the infrared visible and UV regions.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::177fa3ce1c3a8ccb51544458ce7b72ddTest
https://doi.org/10.1063/1.3643590Test