Fossil fuel combustion by-products, including particulate matter (PM2.5), polycyclic aromatic hydrocarbons (PAH), nitrogen dioxide (NO2) and carbon dioxide (CO2), are a significant threat to ...children's health and equality. Various policies to reduce emissions have been implemented to reduce air pollution and mitigate climate change, with sizeable estimated health and economic benefits. However, only a few adverse outcomes in children have been considered, resulting in an undercounting of the benefits to this vulnerable population.
Our goal was to expand the suite of child health outcomes addressed by programs to assess health and economic benefits, such as the Environmental Protection Agency (EPA) Benefits Mapping and Analysis Program (BenMAP), by identifying concentration-response (C-R) functions for six outcomes related to PM2.5, NO2, PAH, and/or PM10: preterm birth (PTB), low birthweight (LBW), autism, attention deficit hyperactivity disorder, IQ reduction, and the development of childhood asthma.
We conducted a systematic review of the literature published between January 1, 2000 and April 30, 2018 to identify relevant peer-reviewed case-control and cohort studies and meta–analyses. In some cases meta-analyses were available that provided reliable C-R functions and we assessed their consistency with subsequent studies. Otherwise, we reviewed all eligible studies published between our search dates.
For each pollutant and health outcome, we present the characteristics of each selected study. We distinguish between C-R functions for endpoints having a causal or likely relationship (PTB, LBW, autism, asthma development) with the pollutants for incorporation into primary analyses and endpoints having a suggestive causal relationship with the pollutants (IQ reduction, ADHD) for secondary analyses.
We have identified C-R functions for a number of adverse health outcomes in children associated with air pollutants largely from fossil fuel combustion. Their incorporation into expanded assessments of health benefits of clean air and climate mitigation policies will provide an important incentive for preventive action.
Recently introduced Zagreb coindices are a generalization of classical Zagreb indices of chemical graph theory. We explore here their basic mathematical properties and present explicit formulae for ...these new graph invariants under several graph operations.
Let G be a molecular graph. The eccentric connectivity index ξc(G) is defined as ξc(G)=∑u∈V(G)degG(u)εG(u), where degG(u) denotes the degree of vertex u and εG(u) is the largest distance between u ...and any other vertex v of G. In this paper exact formulas for the eccentric connectivity index of TUC4C8(S) nanotube and TC4C8(S) nanotorus are given.
The capability of the encapsulated Tung oil was investigated as a scratch healing agent for self-healing coatings. Encapsulation of Tung oil with urea–formaldehyde shell was carried out by in situ ...polymerization. Before the mechanical agitation of microcapsules into epoxy resin, their characteristics were evaluated by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). Released Tung oil from ruptured microcapsules healed the artificial scratch in the coating matrix successfully. Corrosion resistance of healed area was evaluated by electrochemical impedance spectroscopy (EIS) and immersion test; and the results were compared with neat epoxy coating.
Methyl salicylate (MeSal) is an organic compound present in plants during stress events and is therefore a key marker for early plant disease detection. It has usually been detected by conventional ...methods that require bulky and costly equipment, such as gas chromatography or mass spectrometry. Currently, however, chemical sensors provide an alternative for MeSal monitoring, showing good performance for its determination in the vapour or liquid phase. The most promising concepts used in MeSal determination include sensors based on electrochemical and conductometric principles, although other technologies based on mass-sensitive, microwave, or spectrophotometric principles also show promise. The receptor elements or sensitive materials are shown to be part of the key elements in these sensing technologies. A literature survey identified a significant contribution of bioreceptors, including enzymes, odourant-binding proteins or peptides, as well as receptors based on polymers or inorganic materials in MeSal determination. This work reviews these concepts and materials and discusses their future prospects and limitations for application in plant health monitoring.
An irreducible character
χ
of a finite group
G
is called a Heisenberg character if Ker
χ
⊇
G,
G,G
. In this paper, we prove that the group
G
has exactly
r
,
r
≤ 3, Heisenberg characters if and only ...if |
G
/
G
′| =
r
. If
G
has exactly four Heisenberg characters, then |
G
/
G
′| = 4, but the converse is not correct in general. Finally, it is proved that if
G
has exactly five Heisenberg characters, then |
G
/
G
′| = 5 or |
G
/
G
′| = 4 and one of the Heisenberg characters of
G
has the degree 2.
Permanents of Hexagonal and Armchair Chains Nekooei, O.; Barzegar, H.; Ashrafi, A. R.
International journal of mathematics and mathematical sciences,
11/2022, Volume:
2022
Journal Article
Peer reviewed
Open access
The permanent is important invariants of a graph with some applications in physics. If G is a graph with adjacency matrix A=aij, then the permanent of A is defined as permA=∑σ∈Sn∏i=1naiσi, where Sn ...denotes the symmetric group on n symbols. In this paper, the general form of the adjacency matrices of hexagonal and armchair chains will be computed. As a consequence of our work, it is proved that if Gk and Hk denote the hexagonal and armchair chains, respectively, then permAG1=4, permAGk=k+12, k≥2, and permAHk=4k with k≥1. One question about the permanent of a hexagonal zig-zag chain is also presented.
Multilayer nickel-tungsten coatings were deposited on carbon steel using the pulse reverse current technique. Nickel-tungsten layered structure coatings were developed using the continuous and ...alternative variation of pulse duty cycle at two specific and fixed values. In these coatings, the multilayer structure is composed of two nickel-tungsten layers with alternating chemical compositions of 25 wt%W and 11 wt%W. Dynamic electrochemical impedance spectroscopy (DEIS) revealed three time constants in the electrical equivalent circuit corresponding to the electrodeposition mechanism of nickel-tungsten. In order to evaluate the electrochemical behavior of the multilayer structure, the investigation of the multilayer coatings was carried out via cyclic potentiodynamic polarization, in a sulfuric acid media which contained chloride ions. Cyclic voltammetry test was introduced and subsequently employed as a novel electrochemical evaluation for layered structures. Morphological, elemental and Raman analysis were carried out. Analyzing the surface products revealed that nickel tends to dissolve in presence of tungsten, and even more in an electrolyte containing chloride ions. It was also revealed that the diffusive species of the electrolyte encountered a larger interface in multilayer structures. Hence, they spread out along and throughout the active layers; which significantly delays the penetration towards the substrate. Enhanced service life of the noble layers is achieved owing to the galvanic effect. According to the findings, these kinds of coatings are more resistant to localized attack in comparison to monolithic coatings.
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