scholarly journals Some Formulas for the Polynomials and Topological Indices of Nanostructures

2016 ◽  
Vol 24 (2) ◽  
pp. 122-138 ◽  
Author(s):  
Najmeh Soleimani ◽  
Esmaeel Mohseni ◽  
Fahimeh Rezaei ◽  
Fatemeh Khati
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Topological Indices ◽  
Zagreb Indices ◽  
Polycyclic Aromatic ◽  
First Time

Abstract In this paper, we focus on the structure of Polycyclic Aromatic Hydrocarbons (PAHs) and calculate the Omega and its related counting polynomials of nanostructures. Also, the exact expressions for the Theta, Sadhana, Pi, Hyper Zagreb and Forgotten Zagreb indices of linear [n]-Tetracene, V-Tetracenic nanotube, H-Tetracenic nanotube and Tetracenic nanotori were computed for the first time. These indices can be used in QSAR/QSPR studies.

Generalised Multiplicative Indices of Polycyclic Aromatic Hydrocarbons and Benzenoid Systems

2017 ◽  
Vol 72 (6) ◽  
pp. 573-576 ◽  
Author(s):  
V.R. Kulli ◽  
Branden Stone ◽  
Shaohui Wang ◽  
Bing Wei
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Topological Indices ◽  
Zagreb Indices ◽  
Polycyclic Aromatic

AbstractMany types of topological indices such as degree-based topological indices, distance-based topological indices, and counting-related topological indices are explored during past recent years. Among degree-based topological indices, Zagreb indices are the oldest one and studied well. In the paper, we define a generalised multiplicative version of these indices and compute exact formulas for Polycyclic Aromatic Hydrocarbons and jagged-rectangle Benzenoid systems.

scholarly journals Sources and transformations of particle-bound polycyclic aromatic hydrocarbons in Mexico City

2005 ◽  
Vol 5 (6) ◽  
pp. 12741-12773 ◽  
Author(s):  
L. C. Marr ◽  
K. Dzepina ◽  
J. L. Jimenez ◽  
F. Reisen ◽  
H. L. Bethel ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Mexico City ◽  
Aromatic Hydrocarbons ◽  
Heterogeneous Reactions ◽  
Field Campaign ◽  
Aerosol Mass ◽  
Aerosol Mass Spectrometry ◽  
Polycyclic Aromatic ◽  
First Time

Abstract. Understanding sources, concentrations, and transformation of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere is important because of their potent mutagenicity and carcinogenicity. The measurement of particle-bound PAHs by three different methods during the Mexico City Metropolitan Area field campaign in April 2003 presents a unique opportunity for characterization of these compounds and assessment of the methods. The three methods are (1) collection and analysis of bulk samples for time-integrated gas- and particle-phase speciation by gas chromatography/mass spectrometry; (2) aerosol photoionization for fast detection of PAHs on particles' surfaces; and (3) aerosol mass spectrometry for fast analysis of size and chemical composition. This research represents the first time aerosol mass spectrometry has been used to measure ambient PAH concentrations and the first time that fast, real-time methods have been used to quantify PAHs alongside traditional filter-based measurements in an extended field campaign. Speciated PAH measurements suggest that motor vehicles and garbage and wood burning are important sources in Mexico City. The diurnal concentration patterns captured by aerosol photoionization and aerosol mass spectrometry are generally consistent. Ambient concentrations typically peak at ~110 ng m−3 during the morning rush hour and rapidly decay due to changes in source activity patterns and dilution as the boundary layer rises, although surface-bound PAH concentrations decay faster. The more rapid decrease in surface versus bulk PAH concentrations during the late morning suggests that freshly emitted combustion-related particles are quickly coated by secondary aerosol material in Mexico City's atmosphere and may also be transformed by heterogeneous reactions.

scholarly journals The well correlated diffuse interstellar bands at λλ 6196, 6614 Å and their possible companions

2020 ◽  
Vol 496 (2) ◽  
pp. 2231-2240
Author(s):  
A Bondar
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
High Resolution ◽  
Aromatic Hydrocarbons ◽  
Correlation Coefficients ◽  
High Signal ◽  
Signal To Noise ◽  
B Stars ◽  
Diffuse Interstellar Bands ◽  
Polycyclic Aromatic ◽  
First Time

ABSTRACT Considered here is the interrelation between five diffuse interstellar bands (DIBs), λλ 5545, 6113, 6196, 6445 and 6614 Å. Two DIBs (λλ 6196 and 6614 Å) are already known as being well correlated with each other; their relation with three other weaker bands is investigated for the first time. To accomplish this task, high-resolution spectra (λ/δλ ≈100 000) with high signal-to-noise ratios (S/N) of 54 hot O–B stars with reddening 0.12–1.45 mag were used. Analysis of measured equivalent widths has allowed us to establish linear dependences and evaluate linear correlation coefficients as high as 0.968–0.988 between the intensities of these five DIBs. Such a degree of correlation may indicate their common origin. Several spacings in wavenumbers found between these DIBs correspond to the energies of vibrational transitions in some polycyclic aromatic hydrocarbons resulting in IR emissions at λλ 16.4, 11.3, 7.7, 6.2 and 3.3 μm.

scholarly journals CRYSTALLINE AND HETEROCYCLYC AROMATIC COMPOUNDS IN GEORGIAN PETROLEUM

World Science ◽  
2021 ◽  
Author(s):  
Natela Khetsuriani ◽  
Vladimer Tsitsishvili ◽  
Elza Topuria ◽  
Irina Mchedlishvili ◽  
Zaza Molodinashvili
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Aromatic Compounds ◽  
High Intensity ◽  
Oil Wells ◽  
Automated System ◽  
Polycyclic Aromatic ◽  
The Individual ◽  
First Time ◽  
Individual Composition

The individual composition of polycyclic aromatic hydrocarbons has been studied in high boiling (340–590°) fractions of Norio oil (wells 200, 201) which are characterized by high content of aromatic hydrocarbons and high intensity fluorescence. The eluates obtained by adsorption fractionation of aromatic hydrocarbons separated by aniline and concentrates of their crystalline components have been studied by GC, MS and GC-MS methods. For analysis of the obtained data an automated system of mass deconvolution and identification (AMDIS) was used. In the eluates under investigation the following structures were identified: indenes, tetralines, dinaphtilbenzenes, naphthalenes, fluorenes, phenantrenes, antracenes, mono- and polyalkyl derivatives ofnaphtofluorene and phenantrene, and terpeniles. In crystal samples of the eluates the banzantracene, chrizene, their methyl-, dimethyl and trymethylanaloges, phenantrene derivatives, antracenes and pyrenes were identified. The heterocyclic analogues of polycyclic aromatic hydrocarbons likemethylbenzoanthracenes, benzonaphthothiophenes, benzocarbazoles and dibenzthiophene were identified in Georgian oils for the first time.

scholarly journals Atmospheric deposition of chlorinated and brominated polycyclic aromatic hydrocarbons in central Europe analyzed by GC-MS/MS

2021 ◽  
Author(s):  
Rong Jin ◽  
Benjamin A. Musa Bandowe ◽  
Minghui Zheng ◽  
Guorui Liu ◽  
Barbora Nežiková ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Central Europe ◽  
Aromatic Hydrocarbons ◽  
Atmospheric Environment ◽  
Urban Site ◽  
Quadrupole Mass ◽  
Deposition Fluxes ◽  
Background Site ◽  
Polycyclic Aromatic ◽  
First Time

AbstractChlorinated and brominated polycyclic aromatic hydrocarbons (ClPAHs and BrPAHs) are persistent organic pollutants that are ubiquitous in the atmospheric environment. The sources, fate, and sinks in the atmosphere of these substances are largely unknown. One of the reasons is the lack of widely accessible analytical instrumentation. In this study, a new analytical method for ClPAHs and BrPAHs using gas-chromatography coupled with triple quadrupole mass spectrometry is presented. The method was applied to determine ClPAHs and BrPAHs in total deposition samples collected at two sites in central Europe. Deposition fluxes of ClPAHs and BrPAHs ranged 580 (272–962) and 494 (161–936) pg m−2 day−1, respectively, at a regional background site, Košetice, and 547 (351–724) and 449 (202–758) pg m−2 day−1, respectively, at a semi-urban site, Praha-Libuš. These fluxes are similar to those of PCBs and more than 2 orders of magnitude lower than those of the parent PAHs in the region. Seasonal variations of the deposition fluxes of these halogenated PAHs were found with maxima in summer and autumn, and minima in winter at Košetice, but vice versa at Praha-Libuš. The distribution of ClPAHs and BrPAHs between the particulate and dissolved phases in deposition samples suggests higher degradability of particulate BrFlt/Pyr and BrBaA than of the corresponding ClPAHs. A number of congeners were detected for the first time in the atmospheric environment.

New solid phase microextraction fiber based on an eggshell membrane coating for determination of polycyclic aromatic hydrocarbons

RSC Advances ◽  
2016 ◽  
Vol 6 (89) ◽  
pp. 86477-86484 ◽  
Author(s):  
Mohammad Jabbari ◽  
Habib Razmi
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Eggshell Membrane ◽  
Spme Fiber ◽  
Polycyclic Aromatic ◽  
Membrane Coating ◽  
First Time

In this work, we introduced a novel soluble eggshell membrane protein (SEP) coating for the fabrication of a solid phase microextraction (SPME) fiber for the first time.

scholarly journals Computing Eccentric Version of Second Zagreb Index of Polycyclic Aromatic Hydrocarbons (PAHk)

2016 ◽  
Vol 1 (1) ◽  
pp. 247-252 ◽  
Author(s):  
Muhammad Kamran Jamil ◽  
Mohammad Reza Farahani ◽  
Muhammad Imran ◽  
Mehar Ali Malik
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Closed Formula ◽  
Zagreb Index ◽  
Zagreb Indices ◽  
Second Zagreb Index ◽  
Polycyclic Aromatic

AbstractA Recently, Ghorbani et. al. introduced the eccentric versions of first and second Zagreb indices called third and fourth Zagreb indices defined asM3 (G) = Σuv∊E(G) (ε (u) + ε (ν)) and M4 (G) = Σν∊V(G)ε (ν)2, respectively, where ε (ν)is the eccentricity of the vertex ν. In this paper, we compute the closed formula for third Zagreb index of Polycyclic Aromatic Hydrocarbons (PAHk).

A new class of N-doped ionic PAHsviaintramolecular [4+2]-cycloaddition between arylpyridines and alkynes

2018 ◽  
Vol 54 (84) ◽  
pp. 11909-11912 ◽  
Author(s):  
Ravindra D. Mule ◽  
Aslam C. Shaikh ◽  
Amol B. Gade ◽  
Nitin T. Patil
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
New Class ◽  
Polycyclic Aromatic ◽  
First Time ◽  
Tunable Emission

Reported herein, for the first time, is a copper-promoted intramolecular [4+2]-cycloaddition cascade to access ionic N-doped polycyclic aromatic hydrocarbons (PAHs) with tunable emission wavelengths.

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