Attempt to set up a semiquantitative theory of mutual effects of atoms in organic compounds Communication 2. Electronic charges of bonds and physical properties of molecules

Author(s):  
G. V. Bykov
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Feuerherd ◽  
A.-K. Sippel ◽  
J. Erber ◽  
J. I. Baumbach ◽  
R. M. Schmid ◽  
...  

AbstractRapid, high-throughput diagnostic tests are essential to decelerate the spread of the novel coronavirus disease 2019 (COVID-19) pandemic. While RT-PCR tests performed in centralized laboratories remain the gold standard, rapid point-of-care antigen tests might provide faster results. However, they are associated with markedly reduced sensitivity. Bedside breath gas analysis of volatile organic compounds detected by ion mobility spectrometry (IMS) may enable a quick and sensitive point-of-care testing alternative. In this proof-of-concept study, we investigated whether gas analysis by IMS can discriminate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from other respiratory viruses in an experimental set-up. Repeated gas analyses of air samples collected from the headspace of virus-infected in vitro cultures were performed for 5 days. A three-step decision tree using the intensities of four spectrometry peaks correlating to unidentified volatile organic compounds allowed the correct classification of SARS-CoV-2, human coronavirus-NL63, and influenza A virus H1N1 without misassignment when the calculation was performed with data 3 days post infection. The forward selection assignment model allowed the identification of SARS-CoV-2 with high sensitivity and specificity, with only one of 231 measurements (0.43%) being misclassified. Thus, volatile organic compound analysis by IMS allows highly accurate differentiation of SARS-CoV-2 from other respiratory viruses in an experimental set-up, supporting further research and evaluation in clinical studies.


2016 ◽  
Vol 257 ◽  
pp. 147-151 ◽  
Author(s):  
Yi Wang ◽  
Svilen Bobev

Single-crystals of the new compound Ca14NbxIn1–xAs11 have been obtained from a solid-state reaction in a sealed Nb ampoule. The initial experiment had been set up with the aim to investigate the effect of electron doping (via In) on the crystal structure and physical properties of Ca14MnAs11. Subsequent single-crystal X-ray diffraction and elemental analysis work suggested that instead of Ca14MnxIn1–xAs11, the major product of the reaction is the phase Ca14NbxIn1–xAs11. This supposition was corroborated when the title compound was synthesized from a reaction of Ca, In and As in a sealed Nb ampoule, proving that, 1) Mn metal is not included in the structure, and 2) that the inadvertent side reaction of As with the walls of the Nb container is the source of the niobium. The overall structure is isotypic with the tetragonal Ca14AlSb11 structure type (space group I41/acd), although some marked differences between the two must be noted. Current ongoing work is focused on the synthesis of phase pure polycrystalline samples and determination of the physical properties of this unusual transition metal Zintl phase.


Author(s):  
Rohit Misra ◽  
Neti Nageswara Rao

Electrochemical processes are the most adequate tools in the aqueous effluent treatment. The process will not require chemical addition and indeed electrons are the only reactants added to the process to stimulate the reaction. Anodic oxidation of recalcitrant wastewater in a typical electrochemical set-up is particularly interesting because of its ease of operation and scope for scale-up. Nevertheless, electro oxidation in the three-dimensional carbon bed electrodes is a promising process for electrooxidation of effluents containing non-biodegradable organic compounds. The application of three-dimensional carbon bed electrochemical reactor for the degradation of organic pollutant is demonstrated in this chapter. The role of carbon particles in the three-dimensional electrodes reactor is described in this chapter. It has at least two important functions: 1) adsorption of organic compounds from effluents and 2) act as particle electrode. Various operation and design considerations leading to better understanding of carbon bed electrochemical reactors are discussed.


Author(s):  
Hana Kobetičová ◽  
Blanka Galbičková ◽  
Janka Ševčíková ◽  
Maroš Soldán

Abstract The main objective of this paper is to evaluate an efficiency of 3,5 - dichlorophenol removal from wastewater by using alternative adsorbents. Chlorophenols are organic compounds consisting of a benzene ring, OH groups and also atoms of chlorine. Chlorophenols may have a huge isomere variety that means there are differences in their chemical and physical properties. Due to their toxicity it is necessary to remove them from waste water and in this paper an alternative way of such process is described.


KIMIKA ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 38-55
Author(s):  
Florentino C. Sumera ◽  
Stephani Jacutin ◽  
Jan Michael Aficial ◽  
Aileen Filipino

A simple molecular descriptor based on molecular structure for predicting the boiling temperature (BT) of alkanes was developed in this paper. This topological index was used to correlate the boiling temperature of aliphatic hydrocarbons with their bond-valence substituent structure instead of by atom-to-atom branching framework. The predictive power of the bond-valence substituent index (BVSI) was evaluated by comparing it with the popular predictor in literature, the Randic index and the more recently proposed index, the Fi of Manso et al. (2012). The model developed through a second order regression of the plot of the alkane’s boiling temperature versus the BVSI index proved successful in its predictive power such that the method was also applied to a combination of aliphatic hydrocarbons, the alkanes, alkenes, alkynes and cycloalkanes. This topological index provided higher correlation with small deviations compared to the topological index used for comparison. A further study of the BVSI index can be explored for other organic compounds with different functional groups and other physical properties besides their boiling temperatures in the future.


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