Deen Dayal Upadhyay Gorakhpur University

About: Deen Dayal Upadhyay Gorakhpur University is a education organization based out in Gorakhpur, Uttar Pradesh, India. It is known for research contribution in the topics: Thermal decomposition & Lymnaea acuminata. The organization has 1032 authors who have published 1591 publications receiving 21734 citations. The organization is also known as: Gorakhpur University.

Multiband optical variability studies of BL Lacertae

Abstract: We monitored BL Lacertae for 13 nights in optical B, V, R, and I bands during October and November 2014 including quasi-simultaneous observations in V and R bands using two optical telescopes in India. We have studied multi-band optical flux variations, colour variation and spectral changes in this blazar. Source was found to be active during the whole monitoring period and showed significant intraday variability on 3 nights in V and R filters while displayed hints of variability on 6 other dates in R passband and on 2 nights in V filter. From the colour-magnitude analysis of the source we found that the spectra of the target gets flatter as it becomes brighter on intra-night timescale. Using discrete correlation technique, we found that intraday light curves in both V and R filters are almost consistent and well correlated with each other. We also generated spectral energy distribution (SED) of the target using the B, V, R, and I data sets for all 13 nights which could help us investigate the physical process responsible for the observed variations in BL Lacertae objects. We also discuss possible physical causes of the observed spectral variability.

Fungitoxic activity of some essential oils.

Abstract: Of the five essential oils screened against Helminthosporium oryzae, the oils of Cymbopogon martinii (ginger grass oil), Cymbopogon oliveri, Cymbopogon sp. (rosa sofia oil) and Trachyspermum ammi (dethymolysed oil) exhibited strong fungitoxicity and showed wide range of activity. The oils were found more active than some of the prevalent synthetic fungicides and thus might be exploited as natural fungicides if successful infield trials. Besides, these oils were found toxic to various human pathogens.

Similarity solutions for the flow behind an exponential shock in a non-ideal gas

Abstract: Similarity solutions for the flow of a non-ideal gas behind a strong exponential shock driven out by a piston (cylindrical or spherical) moving with time according to an exponential law are obtained. Similarity solutions exist only when the surrounding medium is of constant density. Solutions are obtained, in both the cases, when the flow between the shock and the piston is isothermal or adiabatic. It is found that the assumption of zero temperature gradient brings a profound change in the density distribution as compare to that of the adiabatic case. Effects of the non-idealness of the gas on the flow-field between the shock and the piston are investigated. The variations of density-ratio across the shock and the location of the piston with the parameter of non-idealness of the gas $${\overline{b}}$$ are also obtained.

Sensing properties of CdS-doped tin oxide thick film gas sensor

Abstract: The tin oxide (SnO 2 ) thick film gas sensor is fabricated by employing screen-printing technology. This pure SnO 2 thick film is doped with 1 or 2 wt% of cadmium sulphide (CdS) by its weight and, thereby, the effect of dopant is presented. X-ray diffraction (XRD) analyses are administrated, which suggest that CdS dopant inhibits the crystallite growth leading to nanometric reduction in grain size. The fabricated gas sensor is responsively studied on exposure to liquid petroleum gas (LPG), methanol, and acetone. It is observed that CdS (2 wt%) doped structure exhibited highest response and is more selective to methanol (70 for 5000 ppm) over LPG and acetone at the operating temperature 200 °C. The CdS-doping improved response- and recovery-time from 90 s and 200 s, for undoped-film, to 40 s and 110 s for methanol (5000 ppm at 200 °C).