Active Noise Control using Variable step-size Griffiths’ LMS (VGLMS) algorithm on Real-Time platform

This paper proposes implementation of Griffith’s Variable step-size algorithm for Active Noise Control (ANC) on ADSP-TS201 EZ-Kit Lite. The dual computational units and execution of up to four instructions per cycle which are special features over other processors are best utilized to generate an optimized code. The VGLMS provides improved secondary path estimation and computations involved are marginal as the same gradient is used for step-size computation and coefficient adaptation. The improved secondary path estimate, in turn improves the ANC performance. Further, variable step-size algorithm is used for the main-path to achieve faster convergence. Both for narrowband (fundamental and its harmonics) and broadband noise fields, for a duct the attenuation achieved is 25 dB and 15 dB respectively. The program execution time was only 1.25% for an input sampling rate of 1 KHz which indicates the utility of the special features of the processor considered. Further these features have enabled in bringing down the program memory requirement in the implementation of the algorithm

Structural investigation, spectroscopic and energy level studies of Schiff base: 2-(3�-N-salicylidenephenyl)benzimidazole using experimental and DFT methods

The Schiff base 2-(3�-N-salicylidenephenyl)benzimidazole (Spbzl) was characterized by FT-Raman, 1H NMR, 13C NMR and single crystal X-ray diffraction technique. Crystallographic studies reveal the presence of two water molecules in the asymmetry unit which aid the intermolecular hydrogen bonding with imidazole ring, and the trans-conformation of the azomethine bond. Theoretical computations conducted using density functional theory (DFT) analysis support the experimental facts. Energy levels estimated by DFT studies are in good agreement with the values obtained from cyclic voltammetry technique. Frontier molecular orbital analysis shows that charge transfer has taken place from donor to acceptor moiety, which is also supported by the high hyperpolarizability values in both gaseous and solution phases, indicating high charge transfer capability of the molecule. A comparative theoretical study of Spbzl with derivative 4-((3-(1H-benzimidazol-2-yl)phenylimino)methyl)-3-hydroxybenzoic acid (Pbzlb) having an added anchor group COOH substituted at para position in the acceptor ring has been made. The result shows the feasibility of charge transfer to the semiconductor surface in dye sensitized solar cell (DSSC) applications for Pbzlb. © 2017 Elsevier B.V

Synthesis, characterization, and biological activities of zinc, cadmium, copper, and nickel complexes containing meta -aminophenyl benzimidazole

ZnX 2, CdX 2, CuX 2, and NiX 2 (X=Cl -, Br -, ClO 4 - or NO 3 -) react with meta-aminophenyl benzimidazole in 1:2mole ratio at reflux in methanol to give Zn 2Cl 4L 3·2H 2O, ZnBr 2L 2(OH 2), Zn(OClO 3)L 3ClO 4·3H 2O, CdCl 2L(OH 2), Cd 2Br 4L 3·2H 2O, Cd(ONO 2) 2L 2·2H 2O, Cu 2Cl 4L 32H 2O, Cu 2Br 4L 3, Cu(OClO 3)L 2 2(ClO 4) 2, NiCl 2L(OH 2)2H 2O, NiBrL 3Br·3H 2O, and Ni(OClO 3)L 3ClO 4·H 2O. These complexes were characterized by elemental analysis, melting point, TGA, conductivity, magnetic moment measurements, IR, far-IR, NMR, electronic, and mass spectral studies. Based on these studies, Zn 2Cl 4L 3·2H 2O and Cd 2Br 4L 3·2H 2O were assigned binuclear structures while Zn(OClO 3)L 3ClO 4·3H 2O, CdCl 2L(OH 2), Cd(ONO 2) 2L 2·2H 2O, NiCl 2L(OH 2) ·2H 2O, and NiBrL 3Br·3H 2O were mononuclear with tetrahedral geometry. The copper complexes were binuclear and exhibit strong antiferromagnetic coupling at room temperature. Square pyramidal geometry was proposed for halo complexes of copper and ZnBr 2L 2(OH 2) and square-planar geometry for perchlorato complexes of copper and nickel. All the synthesized compounds were screened for antimicrobial activities. © 2012 Copyright Taylor and Francis Group, LLC

Syntheses, characterizations, and antimicrobial activities of binuclear ruthenium(III) complexes containing 2-substituted benzimidazole derivatives

Binuclear ruthenium(III) complexes RuX3L2· nH2O (X=Cl, L=L1, L2, L3; n=1, L4 and L5, X=Br; L=L3), RuX3L 1.52·nH2O (X=Br, L=L1; n=0, L4; n=6 and L5; n=10), and RuX3L 22 (X=Br, L=L2) have been isolated by treatment of hydrated RuX3 (X=Cl/Br) in acetone with 2-(2â²-aminophenylbenzimidazole) (L1), 2-(3â²- aminophenylbenzimidazole) (L2), 2-(3â²-N-salicylidinephenyl) benzimidazole (L3), 2-(3â²-pyridylbenzimidazole) (L 4), and 2-(4â²-pyridylbenzimidazole) (L5) in acetone. The complexes were characterized by elemental analysis, conductivity and magnetic susceptibility measurements, IR, electronic, EPR, and mass spectral studies. The complexes were dimeric; based on analytical and spectral studies, an octahedral geometry was proposed for the complexes. The synthesized complexes were screened against Gram-positive and Gram-negative bacteria and fungi. © 2012 Taylor & Francis

2-Methoxy-4-[3-(3-nitrophenyl)-4,5-dihydro-1H-pyrazol-5-yl]phenol

In the title compound, C16H15N3O4, the pyrazole ring has an envelope conformation, with the C atom substituted by the 2-methoxyphenol ring as the flap. Its mean plane makes dihedral angles of 56.78 (9) and 9.7 (1)° with the 2-methoxyphenol and 3-nitrophenyl rings, respectively. The benzene rings are inclined to one another by 49.37 (8)°. In the crystal, molecules are linked by pairs of O—H...N hydrogen bonds, forming inversion dimers with an R22(16) ring motif. The dimers are linked by C—H...O hydrogen bonds, forming slabs parallel to the ac plane. There are slipped parallel π–π interactions present within the slabs, involving inversion-related 2-methoxyphenol rings [intercentroid distance = 3.729 (1) Å] and inversion-related 3-nitrophenyl rings [intercentroid distance = 3.831 (1) Å]

N′-[(1E)-4-Hydroxy-3-Methoxybenzylidene]isonicotinohydrazide Monohydrate

In the title hydrate, C\sb 14H\sb 13N\sb 3O\sb 3⋅H\sb 2O, the dihedral angle between the pyridine and benzene rings is 2.52(9)\circ. Intra\-molecular O—-H⋅sO hydrogen bonds occur. In the crystal, O—-H⋅sO, O—-H⋅sN, N—-H⋅sO and C—-H⋅sO hydrogen bonds link the components into a three-dimensional network. π—π inter\-actions are also observed

Effect of solvents on photophysical properties and quenching of 2-3-(1H-benzimidazole-2-yl) phenyl carbonoimidoylphenol

The effect of solvents of varying polarity on the absorption and fluorescence emission of the Schiff base, 2-3-(1H-benzimidazole-2-yl) phenylcarbonoimidoylphenol, was studied using Lippert-Mataga bulk polarity function, Reichardt's microscopic solvent polarity parameter and Kamlet's multiple linear regression approach. The spectral properties follow Reichardt's microscopic solvent polarity parameter better than Lippert-Mataga bulk polarity parameter, indicating the presence of both general solute-solvent interactions and specific interactions. Catalan's multiple linear regression approach indicates the major role of solvent polarizability/dipolarity influence compared with solvent acidity or basicity. The solvatochromic effect was utilized to calculate the dipole moments of ground and excited states of the Schiff base using different methods. Bathochromic shift in the emission spectrum and the increase in dipole moment in the excited state signifies the intramolecular charge transfer character in the emitting singlet state. Fluorescence quenching by aniline was also studied in 1,4-dioxane and n-butanol, and the results were analyzed using sphere of action static quenching and finite sink approximation models. © 2014 John Wiley & Sons, Ltd

(2E)-1-(5-Bromothiophen-2-yl)-3-(4-chlorophenyl)prop-2-en-1-one

In the title compound, C13H8BrClOS, the thiophene and phenyl rings are inclined by 40.69 (11) to each other. The crystal structure is characterized by C—H interactions, which link the molecules into broad layers parallel to (100). Short BrCl contacts [3.698 (1) A˚ ] link these layers along [100]