Optical properties of calcium aluminate phosphors

Thermoluminescence properties of CaAl2O4 was studied. It was found that firstly the TL intensity increases with increase in UV irradiation time and it attains a maximum value for 20 minute irradiation time. TL intensity decreases with further increase in irradiation time

Thermoluminescence and Mechanoluminescence studies of (Cd0.95 Zn0.05)S: Ag doped phosphor

Through the execution of experimental investigation, mechanoluminescence of (Cd,Zn)S: Ag phosphor was studied which is synthesized by solid state reaction. In the observation, the peak value of ML depends on different concentration. It is seen that ML intensity increases with Ag ion concentration in (Cd, Zn)S phosphor. The peak value of TL depends on the different UV-irradiation time. It is seen that as UV-irradiation exposure increases the TL intensity also increases

Microwave Assisted Synthesis, Characterization and Anti-Tubercular Activity of 4-Quinolylhydrazone

A series of 4-quinolylhydrazone derivatives was synthesized by reaction of 4-quinolylhydrazine and various substituted carboxaldehyde out of that most of the derivatives show significant antitubercular properties. The microwave assisted organic synthesis was applied to synthesize a series of 4-quinolylhydrazone derivatives. The characterizations of newly synthesized derivatives were done by modern analytical techniques like digital melting point apparatus, IR, NMR and mass spectroscopy. Keywords: Mycobacterium tuberculosis, Hydrazone, Quinoline, Carboxaldehyde

Effect of Annealing on Magnetic and Structural Properties of FeNi Thin Films

In this work, we have deposited FeNi (60 nm) film on Si (111) substrate using electron beam evaporation technique. XRD measurements carried out on thin film with annealing the sample from 100 to 400 °C show increase in intensity of the FeNi (111) diffraction peak. The particle size increases from 19 nm (as deposited sample) to 27 nm (400 °C) with annealing. The magnetization measurements carried out using MOKE technique show enhancement in coercivity with annealing. The overall results are attributed in terms of annealing induced structural change which modify the magnetic properties

Multi-band Optical Variability of the TeV Blazar PG 1553+113 in 2019

We report the flux and spectral variability of PG 1553+113 on intra-night (IDV) to short-term timescales using BVRI data collected over 91 nights from 28 February to 8 November 2019 employing ten optical telescopes: three in Bulgaria, two each in India and Serbia, and one each in Greece, Georgia, and Latvia. We monitored the blazar quasi-simultaneously for 16 nights in the V and R bands and 8 nights in the V, R, I bands and examined the light curves (LCs) for intra-day flux and colour variations using two powerful tests: the power-enhanced F-test and the nested ANOVA test. The source was found to be significantly (> 99%) variable in 4 nights out of 27 in R-band, 1 out of 16 in V-band, and 1 out of 6 nights in I-band. No temporal variations in the colours were observed on IDV timescale. During the course of these observations the total variation in R-band was 0.89 mag observed. We also investigated the spectral energy distribution (SED) using B, V, R, and I band data. We found optical spectral indices in the range of 0.878+-0.029 to 1.106+-0.065 by fitting a power law to these SEDs of PG 1553+113. We found that the source follows a bluer-when-brighter trend on IDV timescales. We discuss possible physical causes of the observed spectral variability.Comment: 13 pages,8 figures, 7 tables, Accepted for publication in MNRA