Impact of Thermal Fluctuations on Logarithmic Corrected Massive Gravity Charged Black Hole

We investigate the influence of the first-order correction of entropy caused by thermal quantum fluctuations on the thermodynamics of a logarithmic corrected charged black hole in massive gravity. For this black hole, we explore the thermodynamic quantities, such as entropy, Helmholtz free energy, internal energy, enthalpy, Gibbs free energy and specific heat. We discuss the influence of the topology of the event horizon, dimensions and nonlinearity parameter on the local and global stability of the black hole. As a result, it is found that the holographic dual parameter vanishes. This means that the thermal corrections have no significant role to disturb the holographic duality of the logarithmic charged black hole in massive gravity, although the thermal corrections have a substantial impact on the thermodynamic quantities in the high-energy limit and the stability conditions of black holes.     

A cost effective 100 Gbps hybrid MDM–OCDMA–FSO transmission system under atmospheric turbulences

FSO or free space optics is a familiar name used in a wide array of applications in the area of telecommunications. Due to its features of low maintenance cost and deployment time, most of the applications consider FSO as the alternative solution for appropriately replacing fiber optics. In this work, we have designed 100 Gbps FSO system by combining mode division multiplexing (MDM) and optical code multiple access scheme (OCDMA). Ten channels, each carrying 10 Gbps data, are transported over 8 km FSO link by using MDM of two Laguerre Gaussian modes and random diagonal codes. Moreover, the performance of proposed MDM–OCDMA–FSO system is also investigated under atmospheric turbulences.     

Effect of Indium and Antimony Doping on SnS Photoelectrochemical Solar Cells

Single crystals of pure SnS, indium （In） and antimony （Sb） doped SnS are grown by the direct vapor transport technique. Two doping concentrations of 5 at. % and 15 at. % are employed for both In and Sb dopants. In total, five samples are studied, i.e., pure SnS, 5at.% In-doped SnS, 15at.% In-doped SnS, 5at.% Sb-doped SnS and 15at.% Sb-doped SnS single crystals. The energy dispersive analysis of x-ray （EDAX） and x-ray diffraction （XRD） analysis show that all the five as-grown single crystal samples possess near perfect stoichiometry and orthorhombic structure, respectively. The doping of In and Sb in SnS is established from the EDAX data and from the shift in the peak positions in XRD. Photoeleetroehemical （PEC） solar cells are fabricated by using the as- grown single crystal samples along with iodine/iodide electrolytes. Mott-Schottky plots for different compositions of iodine/iodide electrolytes show that O. 025 M 12 ＋ 1 M Nal＋2 M Na2 S04 ＋0.5 M 1-12 S04 will be the most suitable electrolyte. Study of efficiency （η） and fill factor for different intensities of illuminations at room temperature is carried out for the five samples. The In-doped SnS single crystals show better PEC efficiency than the undoped and Sl〉doped SnS single crystals.     

Time-resolved time-dependent photo-acoustic spectroscopy of NO2 in a high frequency multi-resonant cavity

The paper reports the pulsed laser-based time-resolved time-dependent Photo-acoustic (PA) spectroscopy of NO₂ gas in a specially designed multi mode-Resonant PA Cell which is made of Stainless Steel and has a “Q” value of the order of 79. Furthermore the designed cell allows us to excite some of the longitudinal, radial and azimuthal resonance modes of the photo-acoustic signals simultaneously in a very efficient manner. The presence of many newly excited modes occur at 7050 Hz, 10350 Hz and 14650 Hz frequencies is observed for the first time in NO₂ at room temperature. These results are obtained by employing second harmonics i.e. λ=532 nm pulses from Q-switched Nd:YAG laser having 7 ns pulse duration. Some of the new acoustic spectrum lines at higher frequencies are recorded between 0.5–10 ms data acquisition time, which also extends the frequency monitoring range of our system. The study also highlights some of the important aspects such as the decaying behavior of some of these resonant acoustic spectrum lines occur on the expense of others as well as the saturation behavior of some other modes in the NO₂ gas sample. The estimated low level detection limit of NO₂ buffered in air is of the order of 17.9 ppbV.     

Aqua mediated indium(III) chloride catalyzed synthesis of fused pyrimidines and pyrazoles

The utilization of water as solvent and indium trichloride as promoter for the three-component combinatorial synthesis of a variety of bioactive pyrimidine and pyrazole derivatives (2–10) from aldehydes, 1,3-dicarbonyl compounds, and electron-rich amino heterocycles like 6-amino-1,3-dimethyl uracil and 3-methyl-1-phenyl-1H-pyrazol-5-amine catalyzed by indium trichloride under reflux has been studied. A new class of pyrimidine derivatives (2) has also been synthesized and the structure was confirmed by single crystal X-ray analysis. The reactions are environmentally benign, reaction product could be isolated easily and the catalyst could be recycled, which makes it an appealing synthetic protocol.     

Role of magnetic shear on the electrostatic current driven ion-cyclotron instability in the presence of parallel electric field

Recent observation and theoretical investigations have led to the significance of electrostatic ion cyclotron (EIC) waves in the electrodynamics of acceleration process. The instability is one of the fundamental of a current carrying magnetized plasma. The EIC instability has the lowest threshold current among the current driven instabilities. On the basis of local analysis where inhomogeneities like the magnetic shear and the finite width current channel, have been ignored which is prevalent in the magnetospheric environment. On the basis of non-local analysis interesting modification has been incorporated by the inclusion of magnetic shear. In this paper we provide an analytical approach for the non-local treatment of current driven electrostatic waves in presence of parallel electric field. The growth rate is significantly influenced by the field aligned electron drift. The presence of electric field enhances the growth of EIC waves while magnetic shear stabilizes the system.     

Asymmetric aldol additions: use of titanium tetrachloride and (-)-sparteine for the soft enolization of N-acyl oxazolidinones, oxazolidinethiones, and thiazolidinethiones.

Asymmetric aldol additions using chlorotitanium enolates of N-acyloxazolidinone, oxazolidinethione, and thiazolidinethione propionates proceed with high diastereoselectivity for the Evans or non-Evans syn product depending on the nature and amount of the base used. With 1 equiv of titanium tetrachloride and 2 equiv of (-)-sparteine as the base or 1 equiv of (-)-sparteine and 1 equiv of N-methyl-2-pyrrolidinone, selectivities of 97:3 to > 99:1 were obtained for the Evans syn aldol products using N-propionyl oxazolidinones, oxazolidinethiones, and thiazolidinethiones. The non-Evans syn aldol adducts are available with the oxazolidinethione and thiazolidinethiones by altering the Lewis acid/amine base ratios. The change in facial selectivity in the aldol additions is proposed to be a result of switching of mechanistic pathways between chelated and nonchelated transition states. The auxiliaries can be reductively removed or cleaved by nucleophilic acyl substitution. Iterative aldol sequences with high diastereoselectivity can also be accomplished.     

INAA of toxic elements in coal and their transfer into environments

An instrumental neutron activation analytical (INAA) technique is described for the determination of 26 toxic and other trace elements in Eastern Coal (NBS SRM-1632a), local coal and its ash. The coal ash was produced by heating coal at 750°C in a muffled furnace. The transfer of these elements to the environment on the complete compustion of coal is estimated from the difference between the elemental concentration of coal and its ash.     

Determination of toxic elements in tea,leaves by instrumental neutron activation analysis

The concentration of certain toxic and essential elements in various brands of tea consumed locally were determined using instrumental neutron activation analysis. Transference of these elements into the drinkable portion was studied by brewing and boiling tea leaves for two minutes and the approximate intake was calculated from this data. The toxic effects of Hg, Se, As, Br and Sb are briefly discussed.