422 results on '"Gupta, S. K."'
Search Results
402. Metal-free organic dye for dye sensitized solar cells.
- Author
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Saxena, Vibha, Veerender, P., Chauhan, A. K., Jha, P., Aswal, D. K., and Gupta, S. K.
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ORGANIC dyes , *DYE-sensitized solar cells , *PERCHLORATES , *TITANIUM dioxide , *ELECTROLYTES , *ENERGY conversion , *ELECTRODES - Abstract
We demonstrate a dye sensitized solar cell (DSSC) using a new organic dye (i.e. rhodamine 19 perchlorate) sensitized TiO2 electrode. The power conversion efficiency of the cell was found to be 1.1% under white light illumination. The binding modes of the dye to TiO2 electrode as well as the mechanism of the cell are discussed. [ABSTRACT FROM AUTHOR]
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- 2012
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403. Negative differential resistance in freestanding polypyrrole films formed by interface polymerization.
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Jha, Purushottam, Veerender, P., Saxena, Vibha, Chauhan, A. K., Aswal, D. K., and Gupta, S. K.
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ELECTRIC resistance , *POLYPYRROLE , *INTERFACES (Physical sciences) , *POLYMERIZATION , *HYDROCHLORIC acid , *ELECTRIC properties of thin films , *THIN films , *OPTICAL properties - Abstract
The freestanding polypyrrole films were prepared by polymerizing monomers at air/aqueous hydrochloric acid interface. These films were characterized for their morphology, optical and electrical properties. We report here room temperature negative differential resistance (NDR) behavior observed in these films. This effect has been attributed to the H+ ion trapped in the polymer and may be utilized in future organic based memory devices. [ABSTRACT FROM AUTHOR]
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- 2012
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404. Thermoelectric properties of transition metal intercalated layered TiSe2.
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Bhatt, R., Basu, R., Bhattacharya, S., Singh, A., Sen, S., Okram, G. S., Ganesan, V., Aswal, D. K., and Gupta, S. K.
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THERMOELECTRICITY , *TRANSITION metal compounds , *CLATHRATE compounds , *LAYER structure (Solids) , *TRANSPORT theory , *TEMPERATURE effect - Abstract
We present here the effect of intercalation of Pd (x=0.13) and Cu (x=0.15) on the transport and thermoelectric property of TiSe2 dichalcogenide alloy. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) shows that all the samples have layered growth. The room temperature thermopower (S) value of 60 μV/K and -80 μV/K has been observed for Pd0.13TiSe2 and Cu0.15TiSe2 samples, which is nearly an order magnitude higher compared to pure TiSe2. The electrical resistivity (ρ) measurement shows semiconductor behavior for Pd0.13TiSe2, whereas metallic behavior for Cu0.15TiSe2. The power factor (PF=α2/ρ) value of Cu0.15TiSe2 shows improvement of seven order magnitude as compared to pure TiSe2 sample. The PF does not improve for Pd0.13TiSe2 due to enhancement in the resistivity as compared to pure TiSe2. [ABSTRACT FROM AUTHOR]
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- 2012
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405. Thermoelectric Properties of Ca4Mn3-xNbxO10.
- Author
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Bhattacharya, S., Singh, Bharat, Rayaprol, S., Singh, A., Basu, R., Gonal, M. R., Gaur, N. K., and Gupta, S. K.
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THERMOELECTRICITY , *CALCIUM compounds , *TEMPERATURE effect , *SUBSTITUTION reactions , *ELECTRICAL resistivity , *CRYSTAL structure - Abstract
Temperature (T) dependence of thermoelectric (TE) properties of Ca4Mn3O10 (CMO) has been studied from 300 K to 800 K. The thermopower (S) increases with increasing T. The negative sign of S indicates that CMO is an n-type TE material. Resistivity (ρ) decreases monotonously with increasing. Substitution of Nb for Mn in small percentage (∼5%) drastically alters the TE and resistivity properties of CMO. We also find that the power factor (P F = S2/ρ) of CMO can be enhances by one order of magnitude, without altering the crystal structure. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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406. Ordering Induced Enhancement of Charge Carrier Mobility In CoPc Thin Films.
- Author
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Samanta, S., Singh, A., Kumar, Arvind, Debnath, A. K., Aswal, D. K., Gupta, S. K., and Yakhmi, J. V.
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ELECTRON mobility , *ELECTRIC charge , *COBALT compounds , *THIN films , *THICKNESS measurement , *CRYSTAL growth , *MOLECULAR beam epitaxy , *TEMPERATURE effect - Abstract
CoPc films of nominal thickness of 20 nm have been grown on LaAlO3 (100) and SrTiO3 bi-cryastal using MBE. Temperature dependent charge transport have been studied in the temperature range 300 K to 100 K. Two order higher mobility at room temperature have been observed in the films on SrTiO3 bi-crystal (∼500 cm2V-1Sec-1) than that of the films grown on (100) LaAlO3 (∼7 cm2V-1Sec-1). The increase in the charge carrier mobility value is attributed to better ordering of the organic molecule. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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407. Implication of Structural Disorder in The Charge Transport Properties of Cobalt-phthalocyanine Thin Films.
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Debnath, A. K., Kumar, A., Samanta, S., Singh, A., Aswal, D. K., Gupta, S. K., and Yakhmi, J. V.
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MOLECULAR structure , *CHARGE transfer , *ORGANOCOBALT compounds , *PHTHALOCYANINES , *THIN films , *SINGLE crystals , *TEMPERATURE effect , *MOLECULAR beam epitaxy - Abstract
The charge transport properties of 100 nm thick cobalt phthalocyanine (CoPc) films grown on single crystal Al2O3 (0001 oriented) and quartz substrates using molecular beam epitaxy, have been investigated as a function of applied bias (± 50 V) at room temperature. Films grown on Al2O3 are highly ordered and exhibited non-hysteretic current-voltage (J-V) characteristics. On the other hand, films grown on quartz substrates are highly disordered and exhibited hysteretic J-V characteristics due to charge trapping. The analysis of J-V characteristics of films on Al2O3 substrates show that the transport is governed by shallow trap mediated space charge limited conduction (SCLC), while for the films grown on the quartz substrate transport is through the exponentially distributed traps mediated SCLC. X-ray photoelectron spectroscopy data show that charge trapping centers in the films grown on quartz substrates are created by chemisorbed oxygen. [ABSTRACT FROM AUTHOR]
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- 2011
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408. Improved H2S and Cl2 Sensing Characteristics of Pure and Au Incorporated WO3 Thin Films.
- Author
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Ramgir, Niranjan S., Ganapathi, S. Kailasa, Kaur, M., Mishra, S., Datta, N., Aswal, D. K., Gupta, S. K., and Yakhmi, J. V.
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HYDROGEN sulfide , *METALLIC films , *TUNGSTEN oxides , *GAS detectors , *CHLORINE , *GOLD , *TEMPERATURE effect , *THICKNESS measurement - Abstract
Gas sensing properties of pure and Au incorporated WO3 thin films towards H2S and Cl2 have been investigated. The sensor films were able to detect H2S and Cl2 selectively at an operating temperature of 150 and 200 °C, respectively. Effect of gas concentration and Au loading have been investigated and correlated with the observed sensitivity values. Pure WO3 films exhibited better sensing characteristics towards H2S (S = 17, 10 ppm, 150 °C) while sensor film containing Au thickness of 21.6 nm exhibited a maximum sensitivity towards Cl2 (S = 89, 10 ppm, 200 °C).. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
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409. Transient Weakening of Earth's Magnetic Shield Probed by a Cosmic Ray Burst.
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Mohanty, P. K., Arunbabu, K. P., Aziz, T., Dugad, S. R., Gupta, S. K., Hariharan, B., Jagadeesan, P., Jain, A., Morris, S. D., Rao, B. S., Hayashi, Y., Kawakami, S., Oshima, A., Shibata, S., Raha, S., Subramanian, P., and Kojima, H.
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GALACTIC cosmic rays , *MAGNETIC shielding , *INTERPLANETARY magnetic fields - Abstract
The GRAPES-3 tracking muon telescope in Ooty, India measures muon intensity at high cutoff rigidities (15-24 GV) along nine independent directions covering 2.3 sr. The arrival of a coronal mass ejection on 22 June 2015 18:40 UT had triggered a severe G4-class geomagnetic storm (storm). Starting 19:00 UT, the GRAPES-3 muon telescope recorded a 2 h high-energy (~20 GeV) burst of galactic cosmic rays (GCRs) that was strongly correlated with a 40 nT surge in the interplanetary magnetic field (IMF). Simulations have shown that a large (17?) compression of the IMF to 680 nT, followed by reconnection with the geomagnetic field (GMF) leading to lower cutoff rigidities could generate this burst. Here, 680 nT represents a short-term change in GMF around Earth, averaged over 7 times its volume. The GCRs, due to lowering of cutoff rigidities, were deflected from Earth's day side by ~210° in longitude, offering a natural explanation of its night-time detection by the GRAPES-3. The simultaneous occurrence of the burst in all nine directions suggests its origin close to Earth. It also indicates a transient weakening of Earth's magnetic shield, and may hold clues for a better understanding of future superstorms that could cripple modern technological infrastructure on Earth, and endanger the lives of the astronauts in space. [ABSTRACT FROM AUTHOR]
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- 2016
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410. Measurement of the radial diffusion coefficient of galactic cosmic rays near the Earth by the GRAPES-3 experiment.
- Author
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Kojima, H., Arunbabu, K. P., Dugad, S. R., Gupta, S. K., Hariharan, B., Jagadeesan, P., Jain, A., Mohanty, P. K., Rakshe, P. S., Ramesh, K., Rao, B. S., Hayashi, Y., Kawakami, S., Nonaka, T., Oshima, A., Shibata, S., Tanaka, K., and Tokumaru, M.
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DIFFUSION coefficients , *GALACTIC cosmic rays , *SOLAR wind - Abstract
The flux of galactic cosmic rays (GCRs) is isotropic in the interstellar space. However, in the heliosphere, the ram pressure of outward-moving solar wind convects the GCRs away from the Sun, thereby producing a density gradient in the radial direction. The diffusion of GCRs due to this gradient and scattering with the irregularities in the interplanetary magnetic field (IMF) induce variations in their flux that can be observed near the Earth. A framework for the diffusion-convection mechanism of GCR propagation developed by Parker and collaborators [Phys. Rev. 110, 1445 (1958); Planet. Space Sci. 13, 9 (1965); Astrophys. J. 772, 46 (2013); Space Sci. Rev. 78, 401 (1996); Astrophys. J. 234, 746 (1979); Astrophys. J. 361, 162 (1990); Space Sci. Rev. 176, 299 (2013)] offers a good description of this phenomenon. One of the outcomes of this framework is an anticorrelation of the variation in solar wind velocity (VSW) and the GCR flux. A second outcome of this gradient in the presence of IMF is the movement of GCRs perpendicular to the ecliptic plane called "Swinson flow." Therefore, (i) the correlated variations of VSW and GCR flux and (ii) the GCR radial density gradient obtained from Swinson flow can each be used to independently measure the radial diffusion coefficient of GCRs in the inner heliosphere. In an earlier work [Phys. Rev. D 91, 121303(R) (2015)], the GCR flux was shown to be anticorrelated with VSW at (-1.33±0.07)×10-3%(km s-1)-1. This anticorrelation yields a radial diffusion coefficient κ=0.97×1019 m² s-1 at 1 AU. In another work [Astropart. Phys. 62, 21 (2015)], the measurement of Swinson flow was used to obtain a GCR radial density gradient of 0.65 AU-1 at a median rigidity of 77 GV. Here, we report a measurement of radial diffusion coefficient κ=1.04×1019 m² s-1 at 1 AU from the above-mentioned density gradient, for a mean VSW of 450 km s-1. Thus, these two distinct approaches essentially yielded similar values of the radial diffusion coefficient κ=1019 m² s-1 at 1 AU, characterizing the diffusion of GCRs at 77 GV. From this value of κ, the mean free path length for parallel diffusion λ∥ was estimated to be 1.2 AU at 77 GV, consistent with earlier reports [Rev. Geophys. Space Phys. 20, 335 (1982); Astrophys. J. 420, 294 (1994); Astrophys. J. 604, 861 (2004)]. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
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411. Was the cosmic ray burst detected by the GRAPES-3 muon telescope on 22 June 2015 caused by a transient weakening of the geomagnetic field or by an interplanetary anisotropy?
- Author
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Mohanty, P. K., Arunbabu, K. P., Aziz, T., Dugad, S. R., Gupta, S. K., Hariharan, B., Jagadeesan, P., Jain, A., Morris, S. D., Nayak, P. K., Rakshe, P. S., Ramesh, K., Rao, B. S., Zuberi, M., Hayashi, Y., Kawakami, S., Subramanian, P., Raha, S., Ahmad, S., and Oshima, A.
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COSMIC ray muons , *GALACTIC cosmic rays , *TELESCOPES - Abstract
The GRAPES-3 muon telescope in Ooty, India had claimed detection of a 2 hour (h) high-energy (∼20 GeV) burst of galactic cosmic-rays (GCRs) through a >50σ surge in GeV muons, was caused by reconnection of the interplanetary magnetic field (IMF) in the magnetosphere that led to transient weakening of Earth's magnetic shield. This burst had occurred during a G4-class geomagnetic storm (storm) with a delay of 1/2h relative to the coronal mass ejection (CME) of 22 June 2015 [P. K. Mohanty et al., Phys. Rev. Lett. 117, 171101 (2016)]. However, recently a group interpreted the occurrence of the same burst in a subset of 31 neutron monitors (NMs) to have been the result of an anisotropy in interplanetary space [P. Evenson et al., Proc. Sci., ICRC2017 (2017) 133] in contrast to the claim in P. K. Mohanty et al., [Phys. Rev. Lett. 117, 171101 (2016)]. A new analysis of the GRAPES-3 data with a fine 10.6° angular segmentation shows the speculation of interplanetary anisotropy to be incorrect, and offers a possible explanation of the NM observations. The observed 28 minutes (min) delay of the burst relative to the CME can be explained by the movement of the reconnection front from the bow shock to the surface of Earth at an average speed of 35 km/s, much lower than the CME speed of 700 km/s. This measurement may provide a more accurate estimate of the start of the storm. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
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412. Association of vitamin D levels, lipid profile and intima media thickness in HIV positive patients.
- Author
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Bajaj, Sarita, Misra, Vatsala, Bharghav, Anudita, Gupta, S. K., Sonkar, K. K., and Ibandalin
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HIV-positive persons , *VITAMIN D , *LIPID metabolism , *OSTEOPOROSIS , *CD4 antigen - Abstract
Background: People with HIV are living decades longer than before due to combination ART; however, complications including CVD< osteoporosis and non AIDS defining malignancies are higher than in the general population. Many of the emerging complications related to chronic HIV infection represent disease processes where vitamin D is known to play an important role. Objectives: A single point cross sectional case control study was conducted in a tertiary care hospital to determine the prevalence of vitamin D deficiency and its association with carotid intima media thickness (CIMT) in HIV patients and to study the association of lipid profile with HIV infection. Out of the 45 HIV positive cases, vitamin D deficiency was found in 42 cases (93.33%) whereas only 33 out of 45 (73.33%) healthy controls. Fifty one point eleven percent of cases had dyslipidemia compared to 15.55% of controls. A positive association was seen between CD4 levels and 25 hydroxy vitamin D. An inverse co-relation between CD4 count and triglycerides and VLDL levels while a positive co-relation with total cholesterol, LDL cholesterol and HDL cholesterol levels was seen. No significant difference was seen in CIMT in cases and controls. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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413. An Unusual Presentation of Ovarian Teratoma: A Case Report.
- Author
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Khanna, Seema, Srivastava, Vivek, Saroj, Sanjai, Mishra, Shashi Prakash, and Gupta, S. K.
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TERATOMA , *OVARIAN tumors , *AGE factors in disease , *COLON tumors , *ORGAN rupture - Abstract
Mature cystic teratomas account for 10-20% of all ovarian neoplasms and are the most common neoplasm in younger patients. Spontaneous rupture of the teratoma is rare and has been occasionally reported. Here we present an unusual case of left ovarian teratoma rupturing into sigmoid colon. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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414. Swine Flu (H1N1) - Pandemic or Bioterrorism.
- Author
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Tandon, Vishal R., Mahajan, Annil, Sharma, Sudhaa, Gupta, S. K., Kumar, Dinesh, and Sharma, Yashpal
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INFLUENZA A virus, H1N1 subtype , *BIOTERRORISM , *BIOSECURITY , *PANDEMICS - Abstract
The author reflects on the issue of H1N1 whether it is a pandemic or bioterrorism. The author states that the current H1N1 virus which started in Mexico in March 2009, has been found of having a combination of genes from pig, bird and human flu viruses, prompting some suspicion that the virus is perpetrated by bad elements. However, the author notes whether the current swine flu outbreak is a pandemic or an attack of bioterrorism, it is still a matter of a debate.
- Published
- 2009
415. Performance Evaluation of Adaptive Optics Systems.
- Author
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Sridharan, Rengaswamy, Bayanna, A. Raja, Srivastava, Nandita, Kumar, Brajesh, Ravindra, B., Gupta, S. K., Jain, Naresh, Ambastha, A., and Venkatakrishnan, P.
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ADAPTIVE optics , *TELESCOPES , *ASTRONOMICAL instruments , *OPTICAL instruments , *SIMULATION methods & models , *ASTRONOMICAL observatories - Abstract
Adaptive Optics (AO) systems improve the resolution of ground based telescopes and allow for long exposure images. Their performance depends on the seeing conditions at the time of observations. In this paper, we evaluate the performance of an AO system under various seeing conditions through simulations. Then we present the wave-front sensing and correction schemes that would be used in the first phase of the AO system to be developed at the Udaipur Solar Observatory. [ABSTRACT FROM AUTHOR]
- Published
- 2003
416. Bending stress induced improved chemiresistive gas sensing characteristics of flexible cobalt-phthalocyanine thin films.
- Author
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Singh, Ajay, Kumar, Ashwini, Kumar, Arvind, Samanta, S., Joshi, Nirav, Balouria, Vishal, Debnath, A. K., Prasad, R., Salmi, Z., Chehimi, M. M., Aswal, D. K., and Gupta, S. K.
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THIN film research , *CHARGE carriers , *POLYETHYLENE terephthalate , *BENDING stresses , *MOLECULAR beam epitaxy - Abstract
We report chemiresistive gas sensing characteristics of cobalt phthalocyanine films deposited on flexible bi-axially oriented polyethylene terephthalate substrates. Charge carrier mobility in these films systematically decreases upon bending, which implies that bending reduces π-π interactions among molecules. At room temperature, these films exhibited a reversible change in resistance on exposure to ammonia (5-50 ppm) along with high sensitivity and selectivity as well as fast response and recovery. The chemiresistive sensing properties were found to improve significantly under bend conditions owing to creation of more numbers of interaction sites. [ABSTRACT FROM AUTHOR]
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- 2013
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417. ChemInform Abstract: A Route for Synthesis of 1,3,5-Trisubstituted Naphthalenes by Reaction of ortho-Substituted Benzylisoquinolium Bromides with α,β-Unsaturated Ketones.
- Author
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Gupta, K. C., Gupta, Vandana, Gupta, A. K., Chaudhary, V. K., Gupta, S. K., Srivastava, S., and Gupta, M. K.
- Abstract
39 examples [ABSTRACT FROM AUTHOR]
- Published
- 2012
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418. Metal-semiconductor transition in ultrathin cobalt-phthalocyanine films grown on SrTiO3 single crystal substrates.
- Author
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Samanta, S., Kumar, Arvind, Singh, A., Debnath, A. K., Veerender, P., Basu, S., Prasad, R., Aswal, D. K., and Gupta, S. K.
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SEMICONDUCTORS , *PHASE transitions , *METALS at low temperatures , *PHTHALOCYANINES , *ELECTRICAL resistivity - Abstract
We have investigated the low temperature charge transport properties of ultrathin cobalt-phthalocyanine films grown on (100) SrTiO3 single crystal substrates. The temperature dependence of resistivity shows an anomalous behavior, i.e., a transition from semiconducting to metallic behavior at around 110 K. We demonstrated that metallic behavior in these films is triggered by compressive strains of the SrTiO3 substrate due to its cubic to tetragonal structural phase transition at 110 K. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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419. Effect of heavy ion implantation on self-assembled single layer InAs/GaAs quantum dots.
- Author
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Sreekumar, R, Mandal, A, Chakrabarti, S, and Gupta, S K
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ION implantation , *MOLECULAR self-assembly , *QUANTUM dots , *INDIUM arsenide , *GALLIUM arsenide , *PHOTOLUMINESCENCE , *WAVELENGTHS , *X-ray diffraction - Abstract
We report the degradation in photoluminescence efficiency of GaAs/(InAs/GaAs) quantum dot (QD) heterostructures subjected to 20 to 50 keV sulfur implantation. Sulfur ions of fluence ranging from 2.5 x 1013 to 2 x 1015 ions cm[?]2 were used for implantation. Implantation resulted in shift in photoluminescence emission towards lower wavelength and degradation in photoluminescence efficiency. X-ray diffraction analysis revealed reduction in crystalline quality of GaAs cap layer and an amorphous layer was accomplished with 50 keV sulfur implantation, with a fluence of 2.5 x 1014 ions cm[?]2. The amorphous layer was formed due to the overlap of defect clusters created during implantation, as a result of exceeding the critical nuclear energy density deposited in the GaAs system. Cross-sectional transmission electron microscopy revealed damage zones in the cap layer and deformation of QDs upon 50 keV sulfur implantation. Creation of damaged/amorphous GaAs layer probably increased the compressive strain in InAs/GaAs QDs, which resulted in change in energy gap of QDs and blue shift in photoluminescence emission. Implantation resulted in decrease in activation energy from 111 meV (20 keV) to 10 meV (50 keV S). Increase in implantation energy created defects/damage profile at a depth in the vicinity of the QDs. Non-radiative recombination of carriers through these defects might be the possible reason for the degradation of photoluminescence efficiency. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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420. "JK Science" Decade of Publishing Unbiased Quality Research.
- Author
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Tandon, Vishal. R., Mahajan, Annil, Sharma, Sudhaa, Gupta, S. K., and Kumar, Dinesh
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SUCCESS , *PERIODICALS , *AUTHORS , *PUBLISHED articles , *MEDICAL journalism - Abstract
The authors reflect on the success of the journal "JK Science." They note that the journal does not charge authors who submit articles, like an acceptance or a per-published page fee. They state that the journal, unlike others, will continue to host printable pdf version of the printed articles for the benefit of its authors.
- Published
- 2009
421. Basilar artery aneurysm treated with coil embolization via persistent primitive hypoglossal artery.
- Author
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Bapuraj, J. R., Ojili, V., Khandelwal, N., Shanbhogue, A. K. P., and Gupta, S. K.
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ANEURYSMS , *VASCULAR diseases , *ARTERIES , *VERTEBRAL artery , *ARTERIAL occlusions , *CATHETERS - Abstract
A saccular aneurysm at the basilar artery bifurcation associated with a persistent primitive hypoglossal artery (PPHA) was successfully treated by endovascular occlusion with Guglielmi detachable coils. As both vertebral arteries were aplasitc, a microcatheter was advanced via PPHA. To the best of our knowledge, this is the first case report describing the treatment of a basilar top aneurysm through the PPHA. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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422. Causes and temporal trends of blindness and severe visual impairment in children in schools for the blind in North India.
- Author
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Titiyal J S, Pal N, Murthy G V S, Gupta S K, Tandon R, Vajpayee R B, and Gilbert C E
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VISION disorders , *BLINDNESS - Abstract
AIMS: To describe the causes of severe visual impairment and blindness (SVI/BL) in children in schools for the blind in north India, and explore temporal trends in the major causes. METHODS: A total of 703 children were examined in 13 blind schools in Delhi. A modified WHO/PBL eye examination record for children with blindness and low vision which included sections on visual acuity, additional non-ocular disabilities, onset of visual loss, the most affected anatomical part of the eye concerning visual impairment, and the aetiological category of the child's disorder based on the timing of insult leading to visual loss was administered in all children. RESULTS: With best correction, 22 (3.1%) were severely visually impaired (visual acuity in the better eye of <6/60) and 628 (89.3%) children were blind (visual acuity in the better eye of <3/60). Anatomical sites of SVI/BL were whole globe in 27.4% children, cornea 21.7%, retina 15.1%, and lens 10.9%. The underlying cause of visual loss was undetermined in 56.5% children (mainly abnormality since birth 42.3% and cataract 8.3%), childhood disorders were responsible in 28.0% (mainly vitamin A deficiency/measles 20.5%), and hereditary factors were identified in 13.4%. Study of temporal trends of SVI/BL by comparing causes in children in three different age groups-5-8 years, 9-12 years, and 13-16 years-suggests that retinal disorders have become more important while childhood onset disorders (particularly vitamin A deficiency) have declined. CONCLUSIONS: Almost half of the children suffered from potentially preventable and/or treatable conditions, with vitamin A deficiency/measles and cataract the leading causes. Retinal disorders seem to be increasing in importance while childhood disorders have declined over a period of 10 years. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
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