Aqua­(di-2-pyridyl­amine-κ2 N 2,N 2′)(pyridine-2,6-dicarboxyl­ato-κ3 O 2,N,O 6)zinc monohydrate

In the title compound, [Zn(C7H3NO4)(C10H9N3)(H2O)]·H2O, the ZnII atom has a distorted octa­hedral coordination geometry. One of the water mol­ecules is coordinated with the ZnII ion and this mol­ecule forms an O—H⋯O inter­action with the lattice water mol­ecule. The pyridine-2,6-dicarboxyl­ate ligand is almost planar (r.m.s. deviation = 0.0242 Å). In the crystal, C—H⋯O, C—H⋯N, O—H⋯O and N—H⋯O hydrogen bonds are present

A third monoclinic polymorph of 3,4,5-trihy­droxy­benzoic acid monohydrate

The title compound, C7H6O5·H2O, is a new polymorph of the structures reported by Jiang et al. (2000 ▶) [Acta Cryst. C56, 594–595] and Okabe et al. (2001 ▶) [Acta Cryst. E57, o764–o766]. The gallic acid mol­ecule is essentially planar (r.m.s. deviation = 0.550 Å). An intra­molecular O—H⋯O hydrogen bond occurs in the gallic acid mol­ecule, which is linked to the water mol­ecule by a further O—H⋯O hydrogen bond. In the crystal, the components are linked by O—H⋯O hydrogen bonds. The hydrogen-bonding pattern differs from those reported for the previous polymorphs

2-(2-Iodo­phen­yl)isoindoline-1,3-dione

In the title compound, C14H8INO2, the dihedral angle between the isoindole ring and the phenyl ring of the 1-iodo­benzene group is 84.77 (15)°. There is a short inter­molecular I⋯O contact of 3.068 (3) Å in the crystal

(E)-5-Phenyl-N-(2-thienylmethyl­ene)-1,3,4-thia­diazole-2-amine

In the title compound, C13H9N3S2, the thio­phene and phenyl rings are oriented at dihedral angles of 8.00 (7) and 6.31 (7)°, respectively, with respect to the central thia­diazole ring. No significant C—H⋯S and π–π inter­actions exist in the crystal structure

2-[(2-Meth­oxy­eth­yl)sulfan­yl]-4-(2-methyl­prop­yl)-6-oxo-1,6-dihydro­pyrimidine-5-carbonitrile

In the title compound, C12H17N3O2S, the 4-methyl-2-methyl­sulfanyl-6-oxo-1,6-dihydro­pyrimidine-5-carbonitrile part of the mol­ecule is almost planar (r.m.s deviation = 0.062 Å). In the crystal, mol­ecules form centrosymmetric dimers via pairs of N—H⋯O hydrogen bonds

Performance optimization of a front-end circuit for capacitance measurements using grey wolf algorithm

2020 Innovations in Intelligent Systems and Applications Conference, ASYU 2020 -- 15 October 2020 through 17 October 2020 -- -- 165305This study aims to optimize certain performance parameters of an analog front-end circuit for capacitance measurement. The front-end circuit produces an output voltage in proportional to the measured capacitance. This output voltage should be demodulated by means of digital or analog demodulators to extract the capacitance information. In order to obtain an accurate and precise capacitance measurement, the front-end circuit's performance parameters must be optimized carefully. In this paper, a transimpedance amplifier consisting of an operational amplifier with a feedback resistor and a feedback capacitor is employed as the front-end topology. The transimpedance amplifier's gain, settling time and outputreferred total noise are the performance criteria which form a multi-parameter optimization problem. These performance criteria primarily depend on the values of the feedback resistor, feedback capacitor and operation frequency. Grey Wolf optimizer Algorithm is used to find these values optimally. To verify the algorithm's results, SPICE based simulations are carried out for two capacitance measurements. © 2020 IEEE

Crystal structure and spectroscopic characterization of (E)-2-(((4-bromo-2-(trifluoromethoxy)phenyl)imino)methyl)-4-nitrophenol: A combined experimental and computational study

A novel compound crystallizes in the triclinic space group P-1 with a = 7.674(4) angstrom, b = 12.584(6) angstrom, c = 15.921(6) angstrom, alpha = 89.62(4)degrees, beta = 84.34(4)degrees, gamma = 73.77(4)degrees and Z=4. This compound contains Schiff base and rings of molecule has (E) configuration with respect to the central C=N double bond. The crystal structure has the intramolecular O-H center dot center dot center dot N and the intermolecular C-H center dot center dot center dot O hydrogen bonds. Molecular modeling of the title compound was done by using density functional theories (DFT). Detailed vibrational assignments have been made on the basis of potential energy distribution (PED). Additionally, chemical shift assignments, investigations of thermodynamical parameters and plotting of molecular electrostatic potential surfaces have been performed with the help of DFT method. In order to understand the electronic transitions of the title compound, time dependent DFT (TD-DFT) calculations were performed in gas phase. The dipole moment, linear polarizabilities, anisotropy and first hyperpolarizabilities values have been also computed using the same method. (C) 2014 Elsevier B.V. All rights reserved