Degree of approximation of functions in the Hölder metric by Borel’s means

After establishing the Fourier character of the series the authors have studied the degree of approximation of functions associated with the same series in the Hölder metric using Borel’s mean.     

Molar extinction coefficients of some carbohydrates in aqueous solutions

Molar extinction coefficients of some carbohydrates viz. l-arabinose (C₅H₁₀O₅), d-glucose (C₆H₁₂O₆), d-mannose (C₆H₁₂O₆), d-galactose (C₆H₁₂O₆), d(-) fructose (C₆H₁₂O₆) and maltose (C₁₂H₂₄O₁₂) in aqueous solutions have been determined at 81, 356, 511, 662, 1173 and 1332 keV by gamma ray transmission method in a narrow beam good geometry set-up. These coefficients have been found to depend upon the photon energy following a 4-parameter polynomial. These extinction coefficients for different sugars having the same molecular formula have same values varying within experimental uncertainty. Within concentration ranges studied, Beer-Lambert law is obeyed very well.     

Synthesis of 1-Isonicotinoyl-3-Methyl-4-(Substituted AZO) Pyrazol-5-Ones

Isonicotinic acid hydrazide (INH) and their derivatives are generally used as antitubercular agent. We synthesised 1-isonicotinoyl-3-methyl-4-(substituted azo) pyrazol-5-one and their derivatives. Their Rf values, chemical analyses and IR spectra were recorded, The compounds had shown significant central nervous system stimulant activity.     

Molecular alignment of biphenyl derivatives -a computational analysis

Molecular alignment of some biphenyl derivatives likes 4'-Nitro-2-biphenylamine (NBPA), 4-Acetyl-3'-chlorobiphenyl (ACBP) and 4-Acetyl-3'-florobiphenyl (AFBP) has been examined. The CNDO/2 method has been employed to compute the net atomic charge and atomic dipole-moment components at each atomic centre. Configurational energy has been computed using a modified Rayleigh- Schrodinger perturbation method at an interval of 0.1 A° in translation and 1° in rotation, and corresponding probabilities have been calculated using MB-statistics. A comparative study of molecular parameters like the total energy, the binding energy and the total dipole moment etc., has been made. On the basis of the stacking and the in-plane interaction energy calculations, all the possible geometrical arrangements between molecular pairing have been obtained. The investigation suggests that a strong intermolecular interaction energy between a pair of NBPA molecules, and the specific minimum energy configuration, determines the alignment of molecules with respect to one another. An attempt has been made to correlate the liquid crystalline properties exhibited by this class of molecules, and thereby develop a molecular model for the liquid crystallinity.     

Molecular ordering of Fluoro-Nematogen in a dielectric medium at phase-transition temperature: a statistical–mechanical approach based on computer simulation

A molecular-ordering study of p-phenylene-4-methoxy benzoyl 4-trifluoromethylbenzoate (FLUORO) in a dielectric medium (benzene) has been carried out on the basis of statistical mechanics and computer simulation. The atomic net charge and atomic dipole moment at each atomic centre has been evaluated using the CNDO/2 method. The modified Rayleigh–Schrodinger perturbation theory with multicentered–multipole expansion method has been employed to evaluate the long-range intermolecular interactions, while ‘6-exp’ potential function has been assumed for the short-range interactions. The total interaction energy values obtained through these computations were used to calculate the probability of each configuration in a dielectric medium at the phase-transition temperature (506?K), using the MB-formula. The flexibility of various interacting configurations was studied in terms of variation of probability due to departure from the most probable configuration. It has been observed that in dielectric medium the energies/probabilities are redistributed, and there is considerable rise in the probability of interaction, although the order of preference remains the same. The results are discussed in the light of experimental observations.     

Inter- and Intra-Molecular Hydrogen Bonding in Bis(2-amino-5-fluoro-3-methylphenyl)disulfide

Abstract  Bis(2-amino-5-fluoro-3-methylphenyl)disulfide was obtained by oxidation of 2-amino-5-fluoro-3-methylbenzenethiol and was characterized by elemental analysis, IR and ¹H-NMR spectroscopy. The X-ray structure was determined. Crystal data: C₁₄H₁₄N₂F₂S₂: Monoclinic, P2₁ /n, a = 11.8268(3), b = 9.5770(3), c = 12.3977(3) ?, β = 98.079(2)°, V = 1390.29(7) ?, Z = 4. The supramolecular structure arises because the NH₂ groups form three center S···H···F hydrogen bonds and two center N–H···F and N–H···S hydrogen bonds. Index Abstract  Inter- and Intra-Molecular Hydrogen Bonding in Bis(2-amino-5-fluoro-3-methylphenyl)disulfide J. E. Drake¹, M. B. Hursthouse², M. E. Light², R. Maheshwari³, K.G. Ojha³, R. Ratnani^3* Bis(2-amino-5-fluoro-3-methylphenyl)disulfide is linked into a three-dimensional frame work by a combination of intermolecular N–H···F and N–H···N and intramolecular N–H···S hydrogen bonds. The supramolecular structure arises because the NH₂ groups form three center S···H···F hydrogen bonds and two center N–H···F and N–H···S hydrogen bonds.      

Therapeutics for COVID-19: from computation to practices—where we are,where we are heading to

Molecular Diversity - After the 1918 Spanish Flu pandemic caused by the H1N1 virus, the recent coronavirus disease 2019 (COVID-19) brought us to the time of serious global health catastrophe....     

Nematic Behavior of 5OCB in a Dielectric Medium at Phase Transition Temperature ‐A Statistical Analysis

A statistical analysis has been carried out to determine the configurationally preference of a pair of 5OCB (4′‐n‐pentyloxy‐4‐biphenylcarbonitrile) molecules with respect to translatory and orientational motions. The CNDO/2 method has been employed to evaluate the net atomic charge and atomic dipole components at each atomic centre of the molecule. Modified Rayleigh‐Schrodinger perturbation theory along with multicentered‐multipole expansion method has been employed to evaluate long‐range intermolecular interactions, while a ‘6‐exp’ potential function has been assumed for short‐range interactions. The total interaction energy values obtained through these computations were used to calculate the probability of each configuration in vacuum and in a dielectric medium at phase transition temperature using Maxwell‐Boltzmann formula. It has been observed that the probabilities are redistributed in dielectric medium and there is considerable rise in the probabilities of interactions, although the order of preference remains the same. On the basis of stacking, in‐plane and terminal interaction energy calculations, all possible geometrical arrangements of the molecular pairs have been considered. The results are discussed in the light of experimental as well as other theoretical observations.     

Statistical Study of Molecular Ordering in a Nematogenic Compound – A Computational Analysis

A computational Analysis has been carried out to determine the configurational preference of a pair of a nematogen, 4,4′‐azodiphenetole (C₂H₅‐O‐C₆H₄‐N=N‐C₆H₄‐O‐C₂H₅) [AZO] molecules with respect to translatory and orientational motions. The CNDO/2 method has been employed to compute the atomic charge and atomic dipole at each atomic centre. Configurational energy has been computed using modified Rayleigh‐Schrodinger perturbation method. The interaction energy values obtained through these computations were used to calculate the probability of each configuration at phase transition temperature using Maxwell‐Boltzmann formula. Further, the flexibility of various configurations has been studied in terms of variation of probability due to small departures from the most probable configuration. Molecular parameters like total energy, binding energy and total dipole moment have been given. Results have been discussed in the light of experimental as well as other theoretical observations.     

Nonlinear transmission and reflection characteristics of plasma/polystyrene one dimensional photonic crystal

Reflection and transmission properties of one-dimensional plasma/polystyrene nonlinear photonic crystal have been investigated theoretically. Reflectance and transmitted amplitude of electromagnetic waves through these periodic multilayered structures are calculated for different intensities of controlling wave. It is found that the reflectance of the proposed structures depends on the intensity of the controlling wave and this property can be exploited in the design of WDM coupler, filter, optical logic gates, etc.