9 research outputs found

    Luminescence properties of the Eu2+ /Eu3 + activated Barium aluminate phosphors with varies Gd3+ concentration

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Transactions of the Indian Ceramic Society on 2015, available online: http://www.tandfonline.com/10.1080/0371750X.2015.1082932[EN] BaAl2O4:Eu2(+)/Eu3(+) (1mol %) co-doped with varying concentrations of Gd3(+) (1, 2, 5 and 10mol%) were prepared by combustion synthesis method at 600 degrees C. All the compositions were investigated for their structural and photoluminescence properties. Samples prepared in open atmosphere showed the presence of both Eu3(+) and Eu2(+) states which indicates the reduction of Eu3(+) to Eu2(+) during the preparation of these compounds. The prepared materials at 600 degrees C showed high intense broad peaks around 498nm corresponding to Eu2(+) and small peaks in the red region which are attributed to the presence of Eu3(+). In the 1000 degrees C annealed compounds, the intensity of the peak at 498nm got increased. The intensity of this broad band for BaAl2O4:Eu2(+)/Eu3(+)(1mol%):Gd3(+)(1mol%) was three times than that of BaAl2O4:Eu2(+)/Eu3(+)(1mol%). Thus second rare earth ion (Gd3(+)) acted as a good sensitizer and enhanced the photoluminescence intensity. The XRD spectra revealed the presence of hexagonal phase of BaAl2O4 as main phase and a small amount of a mixed phase Ba O! 6.6 Al2O3. Doping of Eu3(+), Gd3(+) did not change the crystalline structure of barium aluminate (BaAl2O4).This work was supported by the Generalitat Valenciana through grant PROMETEUS 2009/2013 and the European Commission through Nano CIS project (FP7-PEOPLE2010-IRSES ref. 269279).MarĂ­, B.; Singh, K.; Verma, N.; Mollar GarcĂ­a, MA.; Jindal, J. (2015). Luminescence properties of the Eu2+ /Eu3 + activated Barium aluminate phosphors with varies Gd3+ concentration. Transactions of the Indian Ceramic Society. 74(3):157-161. https://doi.org/10.1080/0371750X.2015.1082932S15716174

    Luminescence Properties of CaAl2O4:Eu3+, Gd3+ Phosphors Synthesized by Combustion Synthesis Method

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    [EN] CaAl2O4:Eu3+ (1 mol.%) co-doped with varying concentration of Gd3+ (1, 2, 5, and 10 mol.%) were prepared by combustion synthesis method at 600 C and further annealed at 1000 ÂșC. All the compositions were investigated for their structural and photoluminescence properties. It was observed that both states of europium i.e. Eu3+ and Eu2+ were present and ratio of these states changes on heating at 1000 ÂșC. The materials synthesized at 600 ÂșC showed high intense peak around 440 nm due to presence of Eu2+ and less intense peaks in the red region which were due to presence of Eu3+. On annealing the compounds at 1000 ÂșC, intensity of peak around 440 nm decreases and intensity of peaks in the red region increases significantly. The 5D0 !7 F3 transition due to Eu3+ at 657 nm appears as the highest intensity peak. All co-doped samples annealed at 1000 ÂșC showed the higher intensity than the mono doped sample which is due to energy transfer from the Gd3+ to Eu3+. The second rare-earth ion (Gd3+) acts as sensitizer and enhances the photoluminescence intensity. The X-ray diffraction spectra reveal the monoclinic phase of CaAl2O4 in all the samples which showed that Eu3+ and Gd3+ do not change the crystalline structure of calcium aluminate.This work was supported by the Generalitat Valenciana through grant PROMETEUS 2009/2013 and the European Commission through Nano CIS project (FP7-PEOPLE-2010-IRSES ref. 269279).This work was supported by the Generalitat Valenciana through grant PROMETEUS 2009/2013 and the European Commission through Nano CIS project (FP7- PEOPLE-2010-IRSES ref. 269279).Verma, N.; Singh, K.; MarĂ­, B.; Mollar GarcĂ­a, MA.; Jindal, J. (2017). Luminescence Properties of CaAl2O4:Eu3+, Gd3+ Phosphors Synthesized by Combustion Synthesis Method. Acta Physica Polonica A. 132(4):1261-1264. https://doi.org/10.12693/APhysPolA.132.1261S12611264132

    Anodic Oxide Films on Niobium and Tantalum in Different Aqueous Electrolytes and Their Impedance Characteristics

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    [EN] The anodic oxide films were prepared on the niobium and tantalum in aqueous electrolyte mixtures containing 1 M CH3COOH + 1 M H3PO4 or 1 M CH3COOH + 1 vol.% HF or 1 M CH3COOH + 1 M H3PO4 + 1 vol.% HF at 30 V for 30 min. The barrier films were obtained on both niobium and tantalum surfaces in all electrolyte mixtures except niobium oxide film formed in 1 M CH3COOH + 1 vol.% HF which is porous in nature. The anodic oxide "pedance spectroscopy at open-circuit potential on Nb and Ta was applied and obtained data were analyzed by fitting with four different equivalent circuits.Verma, N.; Singh, K.; MarĂ­ Soucase, B.; Mollar GarcĂ­a, MA.; Jindal, J. (2016). Anodic Oxide Films on Niobium and Tantalum in Different Aqueous Electrolytes and Their Impedance Characteristics. Acta Physica Polonica A. 129:297-303. doi:10.12693/APhysPolA.129.297S29730312

    The global burden of cancer attributable to risk factors, 2010–19: a systematic analysis for the Global Burden of Disease Study 2019

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    BACKGROUND: Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. METHODS: The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk–outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. FINDINGS: Globally, in 2019, the risk factors included in this analysis accounted for 4·45 million (95% uncertainty interval 4·01–4·94) deaths and 105 million (95·0–116) DALYs for both sexes combined, representing 44·4% (41·3–48·4) of all cancer deaths and 42·0% (39·1–45·6) of all DALYs. There were 2·88 million (2·60–3·18) risk-attributable cancer deaths in males (50·6% [47·8–54·1] of all male cancer deaths) and 1·58 million (1·36–1·84) risk-attributable cancer deaths in females (36·3% [32·5–41·3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20·4% (12·6–28·4) and DALYs by 16·8% (8·8–25·0), with the greatest percentage increase in metabolic risks (34·7% [27·9–42·8] and 33·3% [25·8–42·0]). INTERPRETATION: The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden

    A search for flaring very-high-energy cosmic gamma-ray sources with the L3+C muon spectrometer

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    The L3+C muon detector at the CERN electron-positron collider, LEP, is used for the detection of very-high-energy cosmic gamma-ray sources through the observation of muons of energies above 20, 30, 50 and 100 GeV. Daily or monthly excesses in the rate of single-muon events pointing to some particular direction in the sky are searched for. The periods from mid July to November 1999, and April to November 2000 are considered. Special attention is also given to a selection of known gamma-ray sources. No statistically significant excess is observed for any direction or any particular source. (c) 2006 Elsevier B.V. All rights reserved

    The solar flare of the 14th of July 2000 (L3+C detector results).

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    Contains fulltext : 35185.pdf (publisher's version ) (Open Access
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