A Density Matrix Renormalization Group Method Study of Optical Properties of Porphines and Metalloporphines

The symmetrized Density-Matrix-Renormalization-Group (DMRG) method is used to study linear and nonlinear optical properties of Free base porphine and metallo-porphine. Long-range interacting model, namely, Pariser-Parr-Pople (PPP) model is employed to capture the quantum many body effect in these systems. The non-linear optical coefficients are computed within correction vector method. The computed singlet and triplet low-lying excited state energies and their charge densities are in excellent agreement with experimental as well as many other theoretical results. The rearrangement of the charge density at carbon and nitrogen sites, on excitation, is discussed. From our bond order calculation, we conclude that porphine is well described by the 18-annulenic structure in the ground state and the molecule expands upon excitation. We have modelled the regular metalloporphine by taking an effective electric field due to the metal ion and computed the excitation spectrum. Metalloporphines have $D_{4h}$ symmetry and hence have more degenerate excited states. The ground state of Metalloporphines show 20-annulenic structure, as the charge on the metal ion increases. The linear polarizability seems to increase with the charge initially and then saturates. The same trend is observed in third order polarizability coefficients.Comment: 13 pages, 6 figure

Novel quantum NMR magnetometer non-contact defectoscopy and monitoring technique for the safe exploitation of gas pipelines

Pipeline transportation has already proved to be a high-performance tool of resources transportation for the efficient functioning of modern society. However, an aggressive environment, the modernization of existing pipelines and the building of new pipelines pose a number of problems to be solved for secure exploitation. Such problems include mapping, systems certification, technical inspection and monitoring. Recently much attention has being paid to the effective solution of these problems, with no interference into the functioning of the existing systems (non-contact methods), and the magnetometric technique is one such method. The method presented in this paper is based on the interpretation of the absolute value of the magnetic field of an object, which allows us to carry out measurements more accurately compared to other approaches. This paper presents the preliminary results of the usage of high-precision absolute quantum Overhauser “POS” (proton Overhauser sensor) magnetometers in the oil-and-gas field. The field work conducted in the summer of 2013 showed that this equipment has great potential for safe exploitation of oil-and-gas pipelines. The efficiency of the geophysical equipment for gas pipelines of a large diameter (1400 mm) was also confirmed under actual operating conditions. © 2014 WIT Press.International Journal of Sustainable Development and Planning;WIT Transactions on Ecology and the Environmen

Method for the rapid temperature correction of a transmission in an inhomogeneous atmosphere

The value of the transmission function in a heterogeneous atmosphere is determined by iterative correction of values in particular layers. The iterative equation and a set of absolute values of errors is presented in two tables

Influence of magnetic field variations on measurements by magnetometers using averaging algorithms

The article is devoted to features of modulus magnetic field measurements by means of proton magnetometers. Inertial characteristics of the magnetometers and dynamic errors of variable magnetic field measurements are discussed. Three basic magnetometers averaging algorithms, processing zero crossing times of free precession, are compared. Theoretical and some numerical estimations of the algorithms work are presented for the linear, square and harmonic variations of magnetic field. Key words: Proton magnetometer, data processing, absolute measurements. 1. Methodical Problems of Variations Measure-ment by Means of Inertial Device The magnetic field variation is continuous function of time. However in practical manner a magnetic field mea-suring device always has an action time (Ripka, 2001). The magnetometer can not operate instantly. Short as the mea-surement time will be it is not zero. So a value measured by inertial device is some averaging during a measurement time (Rasson, 1978). There is no problem when magneti

Broadband mode in proton-precession magnetometers with signal processing regression methods

The choice of the signal processing method may improve characteristics of the measuring device. We consider the measurement error of signal processing regression methods for a quasi-harmonic signal generated in a frequency selective device. The results are applied to analyze the difference between the simple period meter processing and regression algorithms using measurement cycle signal data in proton-precession magnetometers. Dependences of the measurement error on the sensor quality factor and frequency of nuclear precession are obtained. It is shown that regression methods considerably widen the registration bandwidth and relax the requirements on the magnetometer hardware, and thus affect the optimization criteria of the registration system. © 2014 IOP Publishing Ltd

Отдаленный результат хирургической коррекции ишемической митральной недостаточности у больной с заднебазальной постинфарктной аневризмой левого желудочка

The article presents a long-term result of surgical correction of ischemic mitral valve insufficiency, left ventricle inferior wall reconstruction. В статье представлен отдаленный результат хирургической коррекции ишемической митральной недостаточности с пластикой постинфарктной заднебазальной аневризмы левого желудочка.

Study of the laws of oxidation of biodiesel

The paper discusses in detail the first stage of the catalytic oxidation of fatty acid methyl esters with atmospheric oxygen. According to the data obtained as a result of processing the kinetic data, it was concluded that the reactivity of the components of biodiesel. It is established that polyunsaturated and monounsaturated compounds have different reactivity from each other. The kinetic pattern of consumption of unsaturated components of biodiesel was set up and kinetic constants were calculated, which are equal to: oxidation of C18/1 k1 = 0.106±0.008 h-1, and oxidation of C18/2 k2 = 0.269±0.005 h-1, respectively