Electron charge form factors and static properties of extremely light 1p-shell nuclei within the anisotropic-oscillator model involving projections

The mirror odd nuclei ⁷Li and ⁷Be and the neutron-rich nucleus ⁶He are considered within a microscopic approach relying on the variational principle. The binding energies of the nuclei, their root-mean-square radii, and the electron charge C0 and C2 form factors are calculated. The resulting form factors are compared with the predictions of the independent-particle model that assumes intermediate coupling. The sensitivity of the nuclear properties obtained here to the choice of nucleon-nucleon potential, to deviations of the nuclear deformation from that which follows from a variation of the total-energy functionals, and to taking projections onto states characterized by definite values of the total angular momentum and its projection is analyzed. A comparison with experimental data is performed.     

Diffusion in Porous Media: Phenomena and Mechanisms

Transport in Porous Media - Two distinct but interconnected approaches can be used to model diffusion in fluids; the first focuses on dynamics of an individual particle, while the second deals with...     

Synthesis of amino-substituted 1,3-bis(tert-butyl-NNO-azoxy)benzenes 2.* 2-amino and 2,4-diamino derivatives

Oxidation of one of the amino groups of 2-bromo-4,6-dichloro-1,3-phenylenediamine to the nitroso group followed by its conversion into thetert-butyl-NNO-azoxy group afforded a derivative ofm-(tert-butyl-NNO-azoxy)aniline,viz., 2-bromo-3-(tert-butyl-NNO-azoxyl)-4,6-dichloroaniline. Analogously, the second amino group was converted into thetert-butyl-NNO-azoxy group to form a derivative of 1,3-bis(tert-butyl-NNO-azoxy)benzene,viz., 3-bromo-2,4-bis(tert-butyl-NNO-azoxyl)-1,5-dichlorobenzene The reaction of the latter with ammonia yielded 2-amino- and 2,4-diamino-substituted 1,3-bis-(tert-butyl-NNO-azoxyl)benzenes. For Part 1, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2126–2130, November, 1999.     

A quantum-chemical study of 1,2,3,4,5,6,7,8-octaazanaphthalene and itsN-oxides

Calculations of hypothetical molecules of octaazanaphthalene and itsN-oxides were performed by the MNDO method with full geometry optimization. Probable decomposition reactions of these compounds were considered. Compounds with more pronounced alternation of charges on adjacent atoms were shown to be more thermodynamically favorable and thermally stable. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 879–881, May, 1999.     

Synthesis of β-nitramino derivatives ofgem-dinitroalkanes

A method for the synthesis of β-nitramino derivatives ofgem-dinitroalkanes by nitration of the products of condensation of sulfamic acid derivatives with the correspondinggem-dinitroalkanes was proposed.     

pyAIR—A New Software Tool for Breathomics Applications—Searching for Markers in TD-GC-HRMS Analysis

Volatile metabolites in exhaled air have promising potential as diagnostic biomarkers. However, the combination of low mass, similar chemical composition, and low concentrations introduces the challenge of sorting the data to identify markers of value. In this paper, we report the development of pyAIR, a software tool for searching for volatile organic compounds (VOCs) markers in multi-group datasets, tailored for Thermal-Desorption Gas-Chromatography High Resolution Mass-Spectrometry (TD-GC-HRMS) output. pyAIR aligns the compounds between samples by spectral similarity coupled with retention times (RT), and statistically compares the groups for compounds that differ by intensity. This workflow was successfully tested and evaluated on gaseous samples spiked with 27 model VOCs at six concentrations, divided into three groups, down to 0.3 nL/L. All analytes were correctly detected and aligned. More than 80% were found to be significant markers with a p-value < 0.05; several were classified as possibly significant markers (p-value < 0.1), while a few were removed due to background level. In all group comparisons, low rates of false markers were found. These results showed the potential of pyAIR in the field of trace-level breathomics, with the capability to differentially examine several groups, such as stages of illness.