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Mishra G.C.,The Op App | Satapathy K.Ku.,The Op App | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University | Kher R.S.,P.A. College
New Journal of Chemistry | Year: 2017

Europium doped monoclinic CaAl2O4 phosphors were obtained at low temperatures (500 °C) by the process of combustion of the corresponding metal nitrate-urea mixtures, over a period of 5 min. The product was investigated by X-ray powder diffraction. Mechanoluminescence (ML) emission spectra were recorded to investigate the luminescence centers. Two ML spectra were observed at around 455 nm and 606 nm. The ML intensity initially increased with time, attained an optimum value for a particular time, then decreased and finally disappeared. It is found that the ML intensity of the phosphor depends on temperature and the gamma ray dose given to it. The fading of the phosphor is quite low; therefore, it may be advantageously used for high temperature dosimetry applications. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.

Kchaou M.,The Op App | Toumi A.,University of Sfax
2013 10th International Multi-Conference on Systems, Signals and Devices, SSD 2013 | Year: 2013

This paper is concerned with the problem of stabilization of continuous-time Takagi-Sugeno (TS) fuzzy systems which are controlled through networks. Network-induced delays, data packet dropouts, and measurement quantization are simultaneously considered for Network signal-transmission. Based on the LyapunovKrasovskii functional approach and a parallel distributed compensation scheme, a delay-dependent stabilization approach is developed for the NCSs, which guarantees that the closed-loop system is asymptotically stable. Finally, an illustrative example is given to illustrate the effectiveness of the proposed design technique. © 2013 IEEE.

Rastogi A.,The Op App | Anurag,Hindu College | Pandey A.K.,Hindu College | Nayan R.,Hindu College
Journal of the Indian Chemical Society | Year: 2013

Diethylenetriamine condenses with hexachloroethane in the presence of nickel(II) or copper(II) ion to produce dodecaaza macrocyclic ligand 3,6,9,12,15,18,19,22,25,26,29,32-dodccaza-1,2,10,11-tetrachlorotricyclo[9, 7-7-72,10]-dotriacontane (DACD). Further, condensation of the resulting copper complex [Cu4(DACD)(H2O) 4]Cl8 with two molecules of each triethylenetetramlne and copper hydroxide yielded a hexanuclear copper complex of the macrocycle 2,5,8,11,13,16,19,21,24,27,30,32,35,38,39,42,45,46,49,52- eicosaazapentacyclo[29·7·7·0,1,12·0 20,31·712,20]dopcntacontaiie (EACD). But, in the template condensation of [Ni2(DACD)]Cl4 with the triethylenetetramine an additional niacrocycle 20,21-dichloro-2,5,8,11,43,16,19, 22,25,28,29,32,35,36,39,42- hcxadecaazatetracyclo[19·7·7·01,12·7 12,20]dotctracontane (DHCD) along with EACD is generated. The products [Ni2(DACD)]Cl4, [Cu4(DACD)(H 2O)4]Cl8, [NI3(DHCD)(H 2O)2]C16·3H2O, [Ni 4(EACD)(H2O)4]CI8·2H 2O and [Cu6(EACD)(H2O)4]Cl 12, and the metal-free ligand hydrochlorides DACD-12HCI, DHCD-16HCI and EACD-20HCI were characterized by elemental analyses, conductivity measurements, melting points and spoctral studies.

Satapathy K.K.,The Op App | Mishra G.C.,The Op App | Kher R.S.,P.A. College | Dhoble S.J.,Rashtrasant Tukadoji Maharaj Nagpur University
RSC Advances | Year: 2015

Mechanoluminescence and thermoluminescence of Tb in CaAl2O4 prepared by a solution combustion method has been reported. Phase purity, formation of a phosphor and surface morphology were confirmed by XRD and SEM techniques. The resulting phosphors were characterized by photoluminescence (PL) to detect incorporation of the dopant. When a gamma-irradiated Tb-doped CaAl2O4 crystal is impulsively deformed, two peaks appear in the ML intensity versus time curve, whereby the first ML peak is found in the deformation region and the second in the post deformation region of the crystals. The energy levels and hence trapping and detrapping mechanism of charge carriers can be explained using ML. The Tb-doped CaAl2O4 phosphor can be used in the dosimetric applications for ionizing radiation. The TL characteristics of CaAl2O4 may be useful for high radiation doses. Thermoluminescence (TL) materials have wide applications in the dosimetry of ionizing radiation, scintillators, X-ray laser materials, etc. The samples were irradiated using a 60Co gamma-ray source at a dose of 0.930 kGy h-1 and the heating rate used for TL measurements was 5 °C s-1. The samples show good TL peaks for 0.2 mol% (urea), 0.2 mol% (hydrazine) and 0.2 mol% (carbohydrazide) doping concentrations of Tb3+ ions. We also report a more detailed theoretical understanding of the mechanism of TL and ML. All TL glow curves obey the second-order kinetics with a single glow peak, which reveals that only one set of trapping parameters is set for a particular temperature. The TL sensitivity was found to depend upon the annealing temperature and Tb3+ doping concentration. The prepared sample may be useful in TL dosimetry. © The Royal Society of Chemistry 2015.

Blicharska M.,Swedish University of Agricultural Sciences | Mikusinski G.,Swedish University of Agricultural Sciences | Godbole A.,The Op App | Sarnaik J.,The Op App
International Journal of Biodiversity Science, Ecosystems Services and Management | Year: 2013

In this paper, we introduce the relatively unknown system of sacred groves in northern Western Ghats to broader scientific community. The social-ecological systems of the sacred groves of this region are areas rich in biodiversity, provide key ecosystem services and are highly valued. Many sacred groves are an important source of water or medicinal resources, as well as regulating services, such as pollination. They are also places for socially important meetings and celebrations. However, initial investigations of sacred groves in the Konkan region of northern Western Ghats have revealed that these sites face many threats, such as for example, development and agriculture encroachment, increased resource use, cattle trampling and renovations of temples that lead to damage in the environment. This threatens the long-term maintenance of the groves biodiversity and services provided by them. We argue that the role of the sacred groves as biodiversity hotspots and providers of ecosystem services cannot be separated from the social context in which they exist. Thus, conservation work in such areas requires a step-wise approach including comprehensive recognition of the natural and social values, capacity building among local communities and design of locally suited incentives with participatory planning and implementation. © 2013 © Taylor & Francis.

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