Estimate of Contribution of Jet Aircraft Operations To Trace Element Concentration at or near Airports

Fordyce, J. S.; Sheibley, D. W.

doi:10.1080/00022470.1975.10470131

Cited by 14 publications

(5 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The association of cations with polycyclic aromatic hydrocarbon (PAH) molecules is an interesting and important problem. The existence of PAH molecules in the interstellar medium and their possible role in forming clusters with iron atoms has been considered. − Many trace metals and their cations are present in hydrocarbon fuels, and they may participate in PAH coalescence, ultimately leading to soot formation. − From a fundamental perspective, it is important to understand the nature of cation−π interactions in metal cation–PAH clusters.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of Na⁺(Benzene) + Benzene Association and Ensuing Na⁺(Benzene)₂* Dissociation

2015

View full text Add to dashboard Cite

Chemical dynamics simulations were used to study Bz + Na(+)(Bz) → Na(+)(Bz)2* association and the ensuing dissociation of the Na(+)(Bz)2* cluster (Bz = benzene). An interesting and unexpected reaction found from the simulations is direct displacement, for which the colliding Bz molecule displaces the Bz molecule attached to Na(+), forming Na(+)(Bz). The rate constant for Bz + Na(+)(Bz) association was calculated at 750 and 1000 K, and found to decrease with increase in temperature. By contrast, the direct displacement rate constant increases with temperature. The cross section and rate constant for direct displacement are approximately an order of magnitude lower than those for association. The Na(+)(Bz)2* cluster, formed by association, dissociates with a biexponential probability, with the rate constant for the short-time component approximately an order of magnitude larger than that for the longer time component. The latter rate constant agrees with that of Rice-Ramsperger-Kassel-Marcus (RRKM) theory, consistent with rapid intramolecular vibrational energy redistribution (IVR) and intrinsic RRKM dynamics for the Na(+)(Bz)2* cluster. A coupled phase space model was used to analyze the biexponential dissociation probability.

show abstract

Section: Introductionmentioning

confidence: 99%

Dynamics of Na⁺(Benzene) + Benzene Association and Ensuing Na⁺(Benzene)₂* Dissociation

2015

View full text Add to dashboard Cite

show abstract

“…For example, jet fuels can contain PPM levels of sodium, potassium, aluminum, calcium, magnesium, copper, and iron, which are present mostly in a dissolved form. 34 The impact of such trace metal impurities in jet fuel on PAH coalescence and the formation of the carbon nuclei has not been assessed.…”

Section: Introductionmentioning

confidence: 99%

“…The existence of PAH molecules in the interstellar medium and the possible role of their complexes with iron atoms in the coagulation of PAH molecules were discussed in previous astrophysical studies. − Many trace metals, for example, alkali, alkaline earth, and transition metal, are present in practical hydrocarbon fuels and in engine lubricating oils. For example, jet fuels can contain PPM levels of sodium, potassium, aluminum, calcium, magnesium, copper, and iron, which are present mostly in a dissolved form . The impact of such trace metal impurities in jet fuel on PAH coalescence and the formation of the carbon nuclei has not been assessed.…”

Section: Introductionmentioning

confidence: 99%

Properties of Complexes Formed by Na⁺, Mg²⁺, and Fe²⁺ Binding with Benzene Molecules

et al. 2014

View full text Add to dashboard Cite

A theoretical investigation was performed to study cation-π interactions in complexes of benzene (Bz) with cations, that is, M(z+)(Bz)n for M(z+) = Na(+), Mg(2+), Fe(2+) and n = 1-3, using MP2 theory with the 6-31+G* and 6-311++G** basis sets and the DFT/(B3LYP and B3LYP-D)/6-311++G** methods. Binding energies and structures of the complexes are reported. The splitting between the quintet and single states of the Fe(2+) complexes was found to depend on the number of benzene molecules in the complex and the complex's structure. All of the M(z+)(Bz) complexes prefer a half-sandwich geometry. A geometry with the cation sandwiched between the two benzene rings was found for the M(z+)(Bz)2 complexes, with the benzene rings either in an eclipsed or staggered conformation. An approximate cyclic structure, with the cation at its center, was found for three benzene molecules interacting with the cation. The cation-benzene binding energy is substantial and equal to 22, 108, and 151 kcal/mol for the Na(+)(Bz), Mg(2+)(Bz), and Fe(2+)(Bz) complexes, respectively. The strength of the interaction of the cation with an individual benzene molecule decreases as the number of benzene molecules bound to the cation increases; for example, it is 108 kcal/mol for Mg(2+)(Bz), but only 71 kcal/mol for Mg(2+)(Bz)3. There is a range of values for the M(z+)(Bz)n intermolecular vibrational frequencies; for example, they are ∼230-360 and ∼10-330 cm(-1) for the Mg(2+)(Bz) and Mg(2+)(Bz)3 complexes, respectively. Binding of the cation to benzene both red and blue shifts the benzene vibrational frequencies. This shifting is larger for the Mg(2+) and Fe(2+) complexes, as compared to those for Na(+), as a result of the former's stronger cation-benzene binding. The present study is an initial step to understand the possible importance of cation-π interactions for polycyclic aromatic hydrocarbon aggregation processes during soot formation.

show abstract

“…In addition, it is possible that soil arsenic levels have been increased because of the local airport, which operates intensively during the summer. Previous studies have detected arsenic in jet fuel at levels of 0.006-0.02 mg L -1 [72] while air pollution from airports releases arsenic at concentrations of 1.0-1.1 ng m -3 [73]. Regarding previous studies of As levels in fish, Makedonski et al (2015) detected fish muscle As concentrations of 1.6-1.8 mg kg -1 w/w in European sea bass (n=4) sampled from the Aegean Sea regions of intensive fishing in Greece.…”

Section: Resultsmentioning

confidence: 99%

HEALTH RISK ASSESSMENT OF ARSENIC CONTAMINATION FROM THE CONSUMPTION OF COMMERCIALLY IMPORTANT EUROPEAN SEA BASS (Dicentrarchus labrax L., 1758)

Yozukmaz

Yabanlı

2022

Mugla Journal of Science and Technology

View full text Add to dashboard Cite

The aquaculture of European sea bass and Gilthead sea bream has increased significantly in Turkey, especially as they are exported mostly to the EU countries. The purpose of this study is to calculate inorganic arsenic (iAs) levels through the determination of total arsenic amounts (AsT) in muscle tissues of European sea bass (Dicentrarchus labrax L., 1758) cultured in cages at sea and earthen ponds and wild sea bass caught from the coast of Mugla, Turkey. This study also presents a risk assessment of European sea bass consumption in terms of consumer health. For this aim, muscle tissues of fish were mineralized with microwave digestion and total arsenic concentrations were detected with the method of inductively coupled plasma mass spectroscopy (ICP-MS). It is found that the highest level of mean arsenic is detected in sea bass cultured in earthen ponds (0.38 mg kg-1) and the amount of mean arsenic is measured as 0.26 mg kg-1 in sea bass cultured off-shore and wild sea bass. It is revaled that there is not any negative outcome for human health as a result of risk assessments based on estimated daily intake (EDI), target hazard quotient (THQ), carcinogenic risk (CR) and lifetime cancer risk (TR).

show abstract

Estimate of Contribution of Jet Aircraft Operations To Trace Element Concentration at or near Airports

Cited by 14 publications

References 5 publications

Dynamics of Na⁺(Benzene) + Benzene Association and Ensuing Na⁺(Benzene)₂* Dissociation

Dynamics of Na⁺(Benzene) + Benzene Association and Ensuing Na⁺(Benzene)₂* Dissociation

Properties of Complexes Formed by Na⁺, Mg²⁺, and Fe²⁺ Binding with Benzene Molecules

HEALTH RISK ASSESSMENT OF ARSENIC CONTAMINATION FROM THE CONSUMPTION OF COMMERCIALLY IMPORTANT EUROPEAN SEA BASS (Dicentrarchus labrax L., 1758)

Contact Info

Product

Resources

About

Estimate of Contribution of Jet Aircraft Operations To Trace Element Concentration at or near Airports

Cited by 14 publications

References 5 publications

Dynamics of Na+(Benzene) + Benzene Association and Ensuing Na+(Benzene)2* Dissociation

Dynamics of Na+(Benzene) + Benzene Association and Ensuing Na+(Benzene)2* Dissociation

Properties of Complexes Formed by Na+, Mg2+, and Fe2+ Binding with Benzene Molecules

HEALTH RISK ASSESSMENT OF ARSENIC CONTAMINATION FROM THE CONSUMPTION OF COMMERCIALLY IMPORTANT EUROPEAN SEA BASS (Dicentrarchus labrax L., 1758)

Contact Info

Product

Resources

About

Dynamics of Na⁺(Benzene) + Benzene Association and Ensuing Na⁺(Benzene)₂* Dissociation

Dynamics of Na⁺(Benzene) + Benzene Association and Ensuing Na⁺(Benzene)₂* Dissociation

Properties of Complexes Formed by Na⁺, Mg²⁺, and Fe²⁺ Binding with Benzene Molecules