Relevant bibliographies by topics / PAHs

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'PAHs'

Author: Grafiati
Published: 4 June 2021
Last updated: 17 January 2024

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Journal articles on the topic "PAHs"

1

Ossai, Embbey K., Chukwujindu Maxwell Iwegbue, Elizabeth E. Ajogungbe, and Godswill O. Tesi. "Polycyclic Aromatic Hydrocarbon and Metal Concentrations in Imported Canned Maize." Turkish Journal of Agriculture - Food Science and Technology 3, no. 1 (September 5, 2014): 53. http://dx.doi.org/10.24925/turjaf.v3i1.53-58.173.

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Concentrations and profile of polycyclic aromatic hydrocarbons(PAHs) and metals (Cd, Pb, Ni, Cr, Fe and Mn) were determined in selected brands of canned maize in the Nigeria market with a view to providing information on the hazards associated with the consumption of these products. The measurement of the concentrations of PAHs was carried out by using a gas chromatography equipped with flame ionization detector (GC-FID) after extraction by ultra-sonication with acetone/dichloromethane and clean-up. The 16 PAH concentrations varied between 45.1 and 335.7 µg/kg. The concentrations of the indicators for occurrence and effects of PAHs in food varied from 3.6 to 114.5 µg/kg for BaP, 6.4 to 168.2 µg/kg for PAH2, 11.8 to 232.7 µg/kg for PAH4 and 19.4 to 327.3 µg/kg for PAH8. The concentrations of metals were determined by using atomic absorption spectrometry after acid digestion. The concentrations of metals in these samples ranged from
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2

Poljanec, Ivna, Helga Medić, Tanja Bogdanović, Sandra Peričević, Danijel Karolyi, Eddy Listeš, and Nives Marušić Radovčić. "Polycyclic aromatic hydrocarbons in four different types of Croatian dry-cured hams." Meso 21, no. 5 (2019): 458–68. http://dx.doi.org/10.31727/m.21.5.4.

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Polycyclic aromatic hydrocarbons (PAHs) represent an important contaminant group in a variety of food products. Since PAHs are commonly present in meat products, this study aimed to determine PAH content in four types of Croatian dry-cured hams (Dalmatian, Drniš, Krk and Istrian) produced by four different processing methods. Determination and quantification of PAHs were performed by High performance liquid chromatography with fluorescence detection (HPLC-FLD). Out of 15 investigated PAHs, 13 compounds were detected. The total average benzo(a)pyrene (BaP) and PAH4 levels obtained from dry-cured hams ranged from 0.05-0.10 µg/kg and 0.41-0.67 µg/kg, respectively. Even though Krk and Istrian dry-cured ham manufacturing processes do not include the smoking phase, no significant differences were found between investigated dry-cured hams in terms of BaP, PAH4, PAH8 and PAH 15 contents. The presence of detected PAHs in non-smoked dry-cured hams could be a result of the addition of spices in the salting phase. BaP and PAH4 contents found in dry-cured ham samples did not exceed the currently legal levels according to the European legislation.
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3

Liu, Junzhi, and Xinliang Feng. "Bottom-Up Synthesis of Nitrogen-Doped Polycyclic Aromatic Hydrocarbons." Synlett 31, no. 03 (December 10, 2019): 211–22. http://dx.doi.org/10.1055/s-0039-1690767.

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Bottom-up organic synthesis serves as an efficient method to provide atomically precise heteroatom-doped polycyclic aromatic hydrocarbons (PAHs) with not only well-defined size and edge structures but also specific concentrations and positions of the heteroatoms. We provide a plenary account of the preparation of nitrogen-doped PAHs (N-PAHs) through 1,3-dipolar cycloaddition between different dipolarophiles, as well as pyrazine-type N-doped diaza-hexa-peri-hexabenzocoronene (diaza-HBC). Additionally, we present the synthesis of a class of helical N-charged PAHs, including one charged aza[5]helicene and two charged aza[4]helicenes. Moreover, the bottom-up organic synthesis strategy is further extended to the construction of novel nitrogen-boron-nitrogen (NBN)-containing PAHs. Finally, we discuss the synthesis of four-coordinate boron chromophores containing 6,12,18-tris(alkyl amine)-5,11,17-triazatrinaphthylene derivative ligands.1 Introduction2 Nitrogen-Doped PAHs Based on Dibenzo-9a-azaphenalene (DBAP)3 Cationic Nitrogen-Doped Helical PAHs4 Nitrogen–Boron–Nitrogen-Doped PAHs5 Conclusion and Outlook
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4

Peng, Pau Lian, and Lee Hoon Lim. "Polycyclic Aromatic Hydrocarbons (PAHs) Sample Preparation and Analysis in Beverages: A Review." Food Analytical Methods 15, no. 4 (January 1, 2022): 1042–61. http://dx.doi.org/10.1007/s12161-021-02178-y.

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AbstractThe monitoring of food contaminants is of interests to both food regulatory bodies and the consumers. This literature review covers polycyclic aromatic hydrocarbons (PAHs) with regard to their background, sources of exposures, and occurrence in food and environment as well as health hazards. Furthermore, analytical methods focusing on the analysis of PAHs in tea, coffee, milk, and alcoholic samples for the last 16 years are presented. Numerous experimental methods have been developed aiming to obtain better limits of detections (LODs) and percent recoveries as well as to reduce solvent consumption and laborious work. These include information such as the selected PAHs analyzed, food matrix of PAHs, methods of extraction, cleanup procedure, LOD, limits of quantitation (LOQ), and percent recovery. For the analysis of tea, coffee, milk, and alcoholic samples, a majority of the research papers focused on the 16 US Environmental Protection Agency PAHs, while PAH4, PAH8, and methylated PAHs were also of interests. Extraction methods range from the classic Soxhlet extraction and liquid–liquid extraction to newer methods such as QuEChERS, dispersive solid-phase microextraction, and magnetic solid-phase extraction. The cleanup methods involved mainly the use of column chromatography and SPE filled with either silica or Florisil adsorbents. Gas chromatography and liquid chromatography coupled with mass spectrometry or fluorescence detectors are the main analytical instruments used. A majority of the selected combined methods used are able to achieve LODs and percent recoveries in the ranges of 0.01–5 ug/kg and 70–110%, respectively, for the analysis of tea, coffee, milk, and alcoholic samples.
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5

Sumer, Gulsah, and Fatih Oz. "The Effect of Direct and Indirect Barbecue Cooking on Polycyclic Aromatic Hydrocarbon Formation and Beef Quality." Foods 12, no. 7 (March 23, 2023): 1374. http://dx.doi.org/10.3390/foods12071374.

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Herein, the effect of direct and indirect barbecue cooking processes, including different cooking degrees (medium and well done), on the formation of polycyclic aromatic hydrocarbons (PAHs) and on certain quality parameters (water content, cooking loss, pH, lipid oxidation) of beef meat was examined. While no significant effect (p > 0.05) of the cooking method was detected on the water content, cooking loss, ∑PAH4 [the sum of benzo[a]pyrene (BaP), benzo[a]anthracene (BaA), chrysen (Chry), and benzo[b]fluoranthene (BbF)], and ∑PAH8 [the sum of BaP, BaA, Chry, benzo[k]fluoranthene (BkF), dibenzo[a,h]anthracene (DahA), benzo[g,h,i]perylene (Bghip), and indeno [1,2,3-cd]pyrene (IncdP)] content, it was determined that it had a significant effect on pH (p < 0.05) and lipid oxidation (TBARS, p < 0.01). While the cooking degree did not have a significant effect (p > 0.05) on the TBARS value, it had a significant effect (p < 0.05) on the water content and pH value, and a very significant effect (p < 0.01) on the cooking loss. While BaA and BaP compounds were detected in all barbecued samples, the DahA compound could not be detected in any of the samples. Varying levels of BaA (up to 5.62 ng/g), Chry (up to 0.43 ng/g), BbF (LOD-..-LOQ), BkF (LOD-..-LOQ), BaP (up to 0.49 ng/g), BghiP (up to 0.82 ng/g), and IncdP (up to 4.99 ng/g) compounds were determined in the samples. While the ∑PAH4 contents varied between 0.71 and 6.35 ng/g, the ∑PAH8 contents varied between 1.12 and 11.34 ng/g. While the increase in cooking level did not affect the ∑PAH4 content, it caused a significant increase in the ∑PAH8 content. The highest BaP (0.49 ng/g), ∑PAH4 (6.35 ng/g), and ∑PAH8 (11.34 ng/g) contents were detected in the meat samples that were well cooked on the barbecue by the direct method. The results have proven that PAHs are formed at varying levels in both meat samples cooked on the barbecue by the direct method and the indirect method. On the other hand, it has been determined that even if 100 g of the meat with the highest BaP and ∑PAH4 content is eaten, the exposure amount remains far below the limit values specified for PAHs. However, paying close attention to the barbecue cooking process is still recommended.
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6

Zhang, L., I. Cheng, D. Muir, and J. P. Charland. "Scavenging ratios of polycyclic aromatic compounds in rain and snow in the Athabasca oil sands region." Atmospheric Chemistry and Physics 15, no. 3 (February 10, 2015): 1421–34. http://dx.doi.org/10.5194/acp-15-1421-2015.

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Abstract. The Athabasca oil sands industry in northern Alberta, Canada, is a possible source of polycyclic aromatic compounds (PACs). Monitored PACs, including polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, and dibenzothiophenes (DBTs), in precipitation and in air at three near-source sites in the Fort MacKay and Fort McMurray area during January 2011 to May 2012, were used to generate a database of scavenging ratios (Wt) for PACs scavenged by both snow and rain. Higher concentrations in precipitation and air were observed for alkylated PAHs and DBTs compared to the other PACs. The sums of the median precipitation concentrations over the period of data analyzed were 0.48 μ g L−1 for the 18 PAHs, 3.38 μ g L−1 for the 20 alkylated PAHs, and 0.94 μ g L−1 for the 5 DBTs. The sums of the median air concentrations for parent PAHs, alkylated PAHs, and DBTs were 8.37, 67.26, and 11.83 ng m−3, respectively. Median Wt over the measurement period were 6100 – 1.1 × 106 from snow scavenging and 350 – 2.3 × 105 from rain scavenging depending on the PAC species. Median Wt for parent PAHs were within the range of those observed at other urban and suburban locations, but Wt for acenaphthylene in snow samples were 2–7 times higher compared to other urban and suburban locations. Wt for some individual snow and rain samples exceeded literature values by a factor of 10. Wt for benzo(a)pyrene, dibenz(a,h)anthracene, and benzo(g,h,i)perylene in snow samples had reached 107, which is the maximum for PAH snow scavenging ratios reported in the literature. From the analysis of data subsets, Wt for particulate-phase dominant PACs were 14–20 times greater than gas-phase dominant PACs in snow samples and 7–20 times greater than gas-phase dominant PACs in rain samples. Wt from snow scavenging were ~ 9 times greater than from rain scavenging for particulate-phase dominant PACs and 4–9.6 times greater than from rain scavenging for gas-phase dominant PACs. Gas-particle fractions of each PAC, particle size distributions of particulate-phase dominant PACs, and the Henry's law constant of gas-phase dominant PACs explained, to a large extent, the different Wt values among the different PACs and precipitation types. The trend in Wt with increasing alkyl substitutions may be attributed to their physico-chemical properties, such as octanol–air and particle partition coefficients and subcooled vapor pressure, which increases gas-particle partitioning and, subsequently, the particulate mass fraction. This study verified findings from a previous study of Wang et al. (2014) that suggested that snow scavenging is more efficient than rain scavenging of particles for equivalent precipitation amounts, and also provided new knowledge of the scavenging of gas-phase PACs and alkylated PACs by snow and rain.
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Pei, Wenjun, Jiaqi Wang, Lu Zhang, Yiwen Guo, Minjie Cao, Ruijie Liu, Ming Chang, and Xingguo Wang. "Effect of Catechin on the Formation of Polycyclic Aromatic Hydrocarbons in Camellia oleifera Oil during Thermal Processing." Foods 12, no. 5 (February 25, 2023): 980. http://dx.doi.org/10.3390/foods12050980.

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Polycyclic aromatic hydrocarbons (PAHs) in oil are affected by many factors, including temperature, time, and PAHs precursors. Phenolic compounds, as beneficial endogenous components of oil, are often associated with the inhibition of PAHs. However, studies have found that the presence of phenols may lead to increased levels of PAHs. Therefore, this study took Camellia oleifera (C. oleifera) oil as the research object, in order to study the effect of catechin in the formation of PAHs under different heating conditions. The results showed that PAH4 were generated rapidly during the lipid oxidation induction period. When the addition of catechin was >0.02%, more free radicals were quenched than generated, thus inhibiting the generation of PAH4. ESR, FT-IR, and other technologies were employed to prove that when the catechin addition was <0.02%, more free radicals were produced than quenched, causing lipid damage and increasing PAHs intermediates. Moreover, the catechin itself would break and polymerize to form aromatic ring compounds, ultimately leading to the conclusion that phenolic compounds in oil may be involved in the formation of PAHs. This provides suggestions for the flexible processing of phenol-rich oil to balance the retention of beneficial substances, and for the safe control of hazardous substances in real-life applications.
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Yang, Yunxiao, Ting Wang, Lei Luo, Qian He, Fangfei Guo, Zhongbao Chen, Yijun Liu, et al. "Co-Exposure of Polycyclic Aromatic Hydrocarbons and Phthalates with Blood Cell-Based Inflammation in Early Pregnant Women." Toxics 11, no. 10 (September 25, 2023): 810. http://dx.doi.org/10.3390/toxics11100810.

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Cumulative evidence has demonstrated that exposure to polycyclic aromatic hydrocarbons (PAHs) or phthalates (PAEs) contributes to a variety of adverse health effects. However, the association of PAHs and PAEs co-exposure with blood cell-based inflammatory indicators during early pregnancy is still unclear. We aimed to investigate the single and mixed associations of exposure to PAHs and PAEs with blood cell-based inflammatory indicators among early pregnant women. A total of 318 early pregnant women were included in this study. General linear regressions were used to estimate the relationships of individual OH-PAHs and mPAEs with blood cell-based inflammatory indicators. The key pollutants were selected by an adapted least absolute shrinkage and selection operator (LASSO) penalized regression model and wasemployed to build the Bayesian kernel machine regression (BKMR) and quantile g-computation (Q-g) models, which can assess the joint association of OH-PAHs and mPAEs with blood cell-based inflammatory indicators. General linear regression indicated that each 1% increase in MOP was associated with a 4.92% (95% CI: 2.12%, 7.68%), 3.25% (95% CI: 0.50%, 6.18%), 5.87% (95% CI: 2.22%, 9.64%), and 6.50% (95% CI: 3.46%, 9.64%) increase in WBC, lymphocytes, neutrophils, and monocytes, respectively. BKMR and Q-g analysis showed that the mixture of OH-PAHs and mPAEs was linked with increased levels of white blood cells (WBC), neutrophils, monocytes, and lymphocytes, and MOP was identified as the dominant contributor. OH-PAHs and mPAEs co-exposure in early pregnancy was associated with elevated blood cell-based inflammatory indicators reactions. More attention should be paid to the inflammation induced by environmental pollution for perinatal women, especially early pregnant women.
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Zhang, L., I. Cheng, D. Muir, and J. P. Charland. "Scavenging ratio of polycyclic aromatic compounds in rain and snow at the Athabasca oil sands region." Atmospheric Chemistry and Physics Discussions 14, no. 13 (July 28, 2014): 19395–429. http://dx.doi.org/10.5194/acpd-14-19395-2014.

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Abstract. Athabasca oil sands industry in northern Alberta, Canada is a possible source of polycyclic aromatic compounds (PACs). Monitored PACs, including polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, and dibenzothiophenes, in precipitation and in air at three near-source sites in the Fort MacKay and Fort McMurray area during May 2011 to August 2012 were analyzed to generate a database of scavenging (or washout) ratios (Wt) for PACs scavenged by both snow and rain. Median precipitation and air concentrations of parent PAHs over the May 2011 to August 2012 period ranged from 0.3–184.9 (chrysene) ng L−1 and 0.01–3.9 (naphthalene) ng m−3, respectively, which were comparable to literature values. Higher concentrations in precipitation and air were observed for alkylated PAHs and dibenzothiophenes. The median precipitation and air concentrations were 11.3–646.7 (C3-fluoranthene/pyrene) ng L−1 and 0.21–16.9 (C3-naphthalene) ng m−3, respectively, for alkylated PAHs, and 8.5–530.5 (C4-dibenzothiophene) ng L−1 and 0.13–6.6 (C2-dibenzothiophene) ng m−3 for dibenzothiophenes and their alkylated derivatives. Median Wt over the measurement period were 6100–1.1 × 106 from snow scavenging and 350–2.3 × 105 from rain scavenging depending on the PAC species. Median Wt for parent PAHs were within the range of those observed at other urban and suburban locations. But Wt for acenaphthylene in snow samples was 2–7 times higher. Some individual snow and rain samples exceeded literature values by a factor of 10. Wt for benzo(a)pyrene, dibenz(a,h)anthracene, and benzo(g,h,i)perylene in snow samples had reached 107, which is the maximum for PAH snow scavenging ratios reported in literature. From the analysis of data subsets, Wt for particulate-phase dominant PACs were 14–20 times greater than gas-phase dominant PACs in snow samples and 7–20 times greater than gas-phase dominant PACs in rain samples. Wt from snow scavenging was ∼9 times greater than rain scavenging for particulate-phase dominant PACs and 4–9.6 times greater than rain scavenging for gas-phase dominant PACs. Gas-particle fractions of each PAC, particle size distributions of particulate-phase dominant PACs, and Henry's Law constant of gas-phase dominant PACs explained, to a large extent, the different Wt values among the different PACs and precipitation types. This study verified findings from a previous study of Wang et al. (2014) which suggested that snow scavenging is more efficient than rain scavenging of particles for equivalent precipitation amount, and also provided new knowledge on the scavenging of gas-phase PACs by snow and rain.
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Habschied, Kristina, Vinko Krstanović, Brankica Kartalović, Vlatko Galić, Tatjana Ledenčan, Krešimir Mastanjević, and Zvonimir Zdunić. "Polycyclic Aromatic Hydrocarbons in Popcorn Corn Varieties and Popcorns." Applied Sciences 13, no. 5 (February 28, 2023): 3107. http://dx.doi.org/10.3390/app13053107.

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Popping corn is a widespread activity and popcorns are one of the most consumed snacks in the world. As popcorn corn is exposed to environmental conditions and agrotechnical measures in the field, polycyclic aromatic hydrocarbons (PAHs) can end up in corn kernels. Since popcorns are popped at higher temperatures, ca. 180 °C, it is reasonable to assume that PAHs can be found in popcorns. The objective of this paper was to preliminarily determine and quantify the incidence of various PAHs in different popcorn varieties and popcorns popped from them, during two consecutive years. PAHs were determined by using GC-MS. Popcorn corn contained only light PAHs, naphthalene (Nap), acenaphthene (Ane), and fluorene (Fln). However, popped popcorns contained heavier PAHs, such as benz[a]anthracene (BaA), chrysene (Chry), and benzo[a]pyrene (BaP) whose ∑PAH4 was 8.39 µg/kg in sample 1 in 2020. The results indicate that popcorns can be a significant source of PAHs and further studies should be conducted. This is concerning since popcorns are favored snacks in all age groups, including children.
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Dissertations / Theses on the topic "PAHs"

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Vestlund, Hanne. "Development of a Method for GC/MS Analysis of PAHs and Alkylated PAHs for Use in Characterization and Source Identification of PAH Contaminated Sites." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-42008.

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Polycyclic aromatic hydrocarbons (PAHs) are toxic and carcinogenic environmental contaminants originating from different sources; petrogenic, pyrogenic or biogenic. Depending on the source of contamination there will be different ratios of PAHs and the effects on the environment will differ. Petrogenic sources will be higher in concentration of alkyl substituted PAHs (APAHs) while pyrogenic sources will be higher in parent PAHs. In the present study a GC/MS method was developed to separate and calibrate PAHs, dibenzothiophenes and alkyl substituted PAHs in a mix containing 49 standards. The method was able to differentiate between PAHs and APAHs with the same mass number; up to six different compounds with the same mass number was separated. The developed method was used to analyse six different soil samples from various contamination sites. PAHs, APAHs and dibenzothiophenes were identified and quantified in all samples. In order to establish the source of contamination, the distribution pattern, the ratio between different PAHs, and the ratio between APAHs and parent PAHs were used. There was a higher ratio of APAHs/PAHs and a lower ratio between the parent PAHs in the soil samples from sites contaminated with oils compared to the other samples, indicating petrogenic source.
Polycykliska aromatiska kolväten (PAH) är giftiga och cancerframkallande miljögifter som härstammar från olika källor; petrogena, pyrogena eller biogena. Olika föroreningskällor kommer att ha olika förhållanden av PAH och effekterna på miljön kommer att skilja. Petrogena källor innehåller högre koncentrationer av alkylsubstituerade PAH (APAH) medan pyrogena källor kommer att ha högre koncentration av PAH. I denna studie har en GC/MS-metod utvecklats för att separera och kalibrera PAH, dibensotiofener och alkylsubstituerade PAH i en blandning innehållande 49 standarder. Metoden kunde skilja mellan PAH och alkylsubstituerade PAH med samma masstal; upp till sex olika föreningar med samma masstal särskildes. Den utvecklade metoden användes för att analysera sex olika jordprover från olika föroreningsplatser. PAH, APAH och dibensotiofener identifierades och kvantifieras i samtliga prover. För att fastställa föroreningskällan användes fördelningsmönstret för APAH och PAH, förhållandet mellan olika PAH och ration mellan APAH och PAH. Det fanns en högre kvot APAH/PAH i jordprover från områden som var förorenade med olja, vilket indikerar på petrogena föroreningskällor.
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Diédhiou, Malick. "Ion Chemistry of Hydrogenated PAHs." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/40452.

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Polycyclic aromatic hydrocarbons (PAHs) are a class of organic molecules suggested to constitute roughly 20% of carbon in the interstellar medium (ISM). These species exist in both neutral and ionic forms and both are potentially involved in processes such as H2 formation. Catalyzing H2 formation necessarily involves the participation of hydrogenated PAHs as reaction intermediates. Employing tandem mass spectrometry and imaging photoelectron photoion coincidence spectroscopy and theory, we have explored the unimolecular reactions of five ionized hydrogenated PAHs that vary in degree and position of hydrogenation: tetralin (1,2,3,4-tetrahydronaphthalene), 9,10-dihydroanthracene (DHA+•), 1,2,3,4-tetra- and 1,2,3,4,9,10-hexa-hydrophenanthrene (THP+• and HHP+•) and 1,2,3,4,5,6,7,8-octahydroanthracene (OHA+•). The major reactions observed were the losses of the hydrocarbons CH3•, C2H4 and C3H5• together with H• atom loss. RRKM modeling of the iPEPICO data suggested that the unimolecular chemistries were based around a two-well potential energy surface in each case. Ionized tetralin can lose all four neutrals via H-shift and ring-opening reactions, or CH3• and C2H4 after interconversion to the 1-methylindane ion, a process similar to that found for ionized 1,2-dihydronaphthalene (isomerizing to form the 1-methylindene ion structure). DHA+• exhibits the same reactions previously observed for 1,2-dihydronaphthalene and 9,10-dihydrophenanthrene, namely competing loss of H• and CH3•. However, the energy required for H•-loss, as predicted by RRKM modeling of the iPEPICO results, was lower than the latter ions, presumably due to an expansion of the electron delocalization across the central ring upon dehydrogenation. OHA+• behaves similarly to ionized tetralin, displaying losses of H•, CH3•, C2H4 and C3H5• in its collision induced dissociation (CID) mass spectra, but under iPEPICO conditions CH3•-loss is not observed. THP+• iii and HHP+• have aspects of both DHA+• and OHA+• chemistries, displaying losses of H•, CH3•, C2H4 and C3H5•. Minimum energies for all observed reaction channels were thus obtained, together with selected mechanisms computationally explored at the B3-LYP/6-31+G(d,p) level of theory. The trend in reactivity in going from tetralin and DHA+• to THP+•, HHP+• and ultimately OHA+• sees decreasing abundance of H• and CH3•-loss and an increasing dominance of the formation of C2H4, C3H5• and higher hydrocarbons with degree of hydrogenation as isomerization to a methyl-substituted ion becomes less significant. As this isomerization decreases in significance, the ions become sources of small hydrocarbon molecules and not hydrogen atoms or molecules.
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Wanene, Wilson Kamau. "Toward curved polycyclic aromatic hydrocarbons (PAHs)." abstract and full text PDF (free order & download UNR users only), 2007. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1445914.

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4

Herwijnen, René van. "Metabolic and cometabolic biodegradation of PAHs." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2003. http://dare.uva.nl/document/87041.

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5

Castaldini, Francesca. "Bioremediation of PAHs - Limitations and soultions." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amslaurea.unibo.it/130/.

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Introduction 1.1 Occurrence of polycyclic aromatic hydrocarbons (PAH) in the environment Worldwide industrial and agricultural developments have released a large number of natural and synthetic hazardous compounds into the environment due to careless waste disposal, illegal waste dumping and accidental spills. As a result, there are numerous sites in the world that require cleanup of soils and groundwater. Polycyclic aromatic hydrocarbons (PAHs) are one of the major groups of these contaminants (Da Silva et al., 2003). PAHs constitute a diverse class of organic compounds consisting of two or more aromatic rings with various structural configurations (Prabhu and Phale, 2003). Being a derivative of benzene, PAHs are thermodynamically stable. In addition, these chemicals tend to adhere to particle surfaces, such as soils, because of their low water solubility and strong hydrophobicity, and this results in greater persistence under natural conditions. This persistence coupled with their potential carcinogenicity makes PAHs problematic environmental contaminants (Cerniglia, 1992; Sutherland, 1992). PAHs are widely found in high concentrations at many industrial sites, particularly those associated with petroleum, gas production and wood preserving industries (Wilson and Jones, 1993). 1.2 Remediation technologies Conventional techniques used for the remediation of soil polluted with organic contaminants include excavation of the contaminated soil and disposal to a landfill or capping - containment - of the contaminated areas of a site. These methods have some drawbacks. The first method simply moves the contamination elsewhere and may create significant risks in the excavation, handling and transport of hazardous material. Additionally, it is very difficult and increasingly expensive to find new landfill sites for the final disposal of the material. The cap and containment method is only an interim solution since the contamination remains on site, requiring monitoring and maintenance of the isolation barriers long into the future, with all the associated costs and potential liability. A better approach than these traditional methods is to completely destroy the pollutants, if possible, or transform them into harmless substances. Some technologies that have been used are high-temperature incineration and various types of chemical decomposition (for example, base-catalyzed dechlorination, UV oxidation). However, these methods have significant disadvantages, principally their technological complexity, high cost , and the lack of public acceptance. Bioremediation, on the contrast, is a promising option for the complete removal and destruction of contaminants. 1.3 Bioremediation of PAH contaminated soil & groundwater Bioremediation is the use of living organisms, primarily microorganisms, to degrade or detoxify hazardous wastes into harmless substances such as carbon dioxide, water and cell biomass Most PAHs are biodegradable unter natural conditions (Da Silva et al., 2003; Meysami and Baheri, 2003) and bioremediation for cleanup of PAH wastes has been extensively studied at both laboratory and commercial levels- It has been implemented at a number of contaminated sites, including the cleanup of the Exxon Valdez oil spill in Prince William Sound, Alaska in 1989, the Mega Borg spill off the Texas coast in 1990 and the Burgan Oil Field, Kuwait in 1994 (Purwaningsih, 2002). Different strategies for PAH bioremediation, such as in situ , ex situ or on site bioremediation were developed in recent years. In situ bioremediation is a technique that is applied to soil and groundwater at the site without removing the contaminated soil or groundwater, based on the provision of optimum conditions for microbiological contaminant breakdown.. Ex situ bioremediation of PAHs, on the other hand, is a technique applied to soil and groundwater which has been removed from the site via excavation (soil) or pumping (water). Hazardous contaminants are converted in controlled bioreactors into harmless compounds in an efficient manner. 1.4 Bioavailability of PAH in the subsurface Frequently, PAH contamination in the environment is occurs as contaminants that are sorbed onto soilparticles rather than in phase (NAPL, non aqueous phase liquids). It is known that the biodegradation rate of most PAHs sorbed onto soil is far lower than rates measured in solution cultures of microorganisms with pure solid pollutants (Alexander and Scow, 1989; Hamaker, 1972). It is generally believed that only that fraction of PAHs dissolved in the solution can be metabolized by microorganisms in soil. The amount of contaminant that can be readily taken up and degraded by microorganisms is defined as bioavailability (Bosma et al., 1997; Maier, 2000). Two phenomena have been suggested to cause the low bioavailability of PAHs in soil (Danielsson, 2000). The first one is strong adsorption of the contaminants to the soil constituents which then leads to very slow release rates of contaminants to the aqueous phase. Sorption is often well correlated with soil organic matter content (Means, 1980) and significantly reduces biodegradation (Manilal and Alexander, 1991). The second phenomenon is slow mass transfer of pollutants, such as pore diffusion in the soil aggregates or diffusion in the organic matter in the soil. The complex set of these physical, chemical and biological processes is schematically illustrated in Figure 1. As shown in Figure 1, biodegradation processes are taking place in the soil solution while diffusion processes occur in the narrow pores in and between soil aggregates (Danielsson, 2000). Seemingly contradictory studies can be found in the literature that indicate the rate and final extent of metabolism may be either lower or higher for sorbed PAHs by soil than those for pure PAHs (Van Loosdrecht et al., 1990). These contrasting results demonstrate that the bioavailability of organic contaminants sorbed onto soil is far from being well understood. Besides bioavailability, there are several other factors influencing the rate and extent of biodegradation of PAHs in soil including microbial population characteristics, physical and chemical properties of PAHs and environmental factors (temperature, moisture, pH, degree of contamination). Figure 1: Schematic diagram showing possible rate-limiting processes during bioremediation of hydrophobic organic contaminants in a contaminated soil-water system (not to scale) (Danielsson, 2000). 1.5 Increasing the bioavailability of PAH in soil Attempts to improve the biodegradation of PAHs in soil by increasing their bioavailability include the use of surfactants , solvents or solubility enhancers.. However, introduction of synthetic surfactant may result in the addition of one more pollutant. (Wang and Brusseau, 1993).A study conducted by Mulder et al. showed that the introduction of hydropropyl-ß-cyclodextrin (HPCD), a well-known PAH solubility enhancer, significantly increased the solubilization of PAHs although it did not improve the biodegradation rate of PAHs (Mulder et al., 1998), indicating that further research is required in order to develop a feasible and efficient remediation method. Enhancing the extent of PAHs mass transfer from the soil phase to the liquid might prove an efficient and environmentally low-risk alternative way of addressing the problem of slow PAH biodegradation in soil.
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Wang, Yu. "Development and application of a solidphase extraction method for simultaneousdetermination of PAHs, oxy-PAHs andazaarenes in water samples." Thesis, Umeå universitet, Kemiska institutionen, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-56332.

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In this study, a solid phase extraction (SPE) method was developed that can be used to extract a wide range of polycyclic aromatic compounds (PACs), including polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs (oxy-PAHs) and azaarenes, from water samples. Three commercially available SPE materials, i.e. Oasis HLB, ISOLUTE C2/C18 (EC) and ISOLUTE PAH, were tested for their capability to accomplish the extraction, and two were chosen for further optimization. Several different combinations of solvents were tested. Experiments were performed on both spiked and real contaminated water samples. The ISOLUTE C2/C18 (EC) performed best on spiked samples for most of the target PACs while the Oasis HLB material was more suitable for real samples. The results from both materials agreed well with the results obtained with a traditional method based on liquid-liquid extraction (LLE) followed by silica gel fractionation. The final method was based on Oasis HLB eluted with dichloromethane/ methanol (7:3) using a flow rate not exceeding 2ml/min. This method was applied on ten real samples collected from a water treatment plant operating at a creosote contaminated wood preservation site in order to exam how much the dissolved concentrations of target PACs varied in the plant. The SPE method is faster and consumes much less solvent than a method based on LLE for instance and it is also less labor intensive. The SPE method is therefore favorable during larger studies on PACs contamination in aqueous environments.
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Lérida, Laura Cano. "New synthetic receptors for sensors for PAHs." Thesis, University of York, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433998.

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Karlsson, Elin. "Förekomst av polycykliska aromatiska kolväten (PAHer) i vilda och odlade blåmusslor." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-45457.

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I denna studie har förekomst av Polycykliska aromatiska kolväten (PAHer) i musslor undersökts. Syftet var att undersöka vilka PAHer som förekom, i vilka halter och ifall dessa nivåer överskred gränsvärdena för humankonsumtion. Vissa PAHer är skadliga för människan då de kan ge upphov till cancer. Vilda och odlade musslor jämfördes för att se om innehållet av PAHer skiljde sig åt. Musslor från sex olika provplatser undersöktes. Två prov handplockades vilda utanför Stenungssund, Sverige. Danska vildfångade musslor undersöktes, likaså vildfångade svenska musslor. Även odlade musslor från Irland och odlade musslor från Sverige undersöktes. Resultaten visar att fluoranten, fenantren, pyren, krysen, benzo(e)pyren och benzo(b)fluoranten var de ämnen som förekom i högst halter. Av de alkylerade PAHerna var 2-metylantracen-9,10-dion, 2-metylfenantren, 2-metylkrysen och 1-metylfluoranten vanligast. Halterna av oxy-PAHer var låga, förutom för antracen-9,10-dion, benzo(h)quinolin samt 2-metylantracen-9,10-dion. Utifrån de riktvärden som finns för humankonsumtion överskred inga musslor gränsvärdena. Inga skillnader kunde ses mellan odlade och vilda musslor. Sammanfattningsvis förekommer PAHer i musslor, men inte i sådan halt att musslorna inte är godkända som livsmedel.
In this study, the presence of PAHs in mussels were investigated. The aim was to examine the occurrence of PAHs, at which levels and if these levels exceeded the limits for human consumption. Some PAHs are toxic to humans as they can give rise to cancer. Wild and cultivated mussels were compared to see if the content of PAHs was different. Mussels from six different test sites were examined. Two wild samples were hand-picked outside Stenungsund, Sweden. Furthermore, wild clams from both Sweden and Denmark were sampled. Also cultured mussels from Ireland and cultured mussels from Sweden were investigated. The results show that fluoranthene, phenanthrene, pyrene, chrysene, benzo(e)pyrene and benzo(b)fluoranthene were the compounds that occurred at the highest levels. The most common alkylated PAHs were 2-methylanthracene-9,10-dione, 2-methylphenanthrene, 2-methylchrysene and 1-methylfluoranthene. The concentrations of oxy-PAHs were low except for anthracene-9,10-dione, benzo(h)quinoline and 2-methylanthracene-9,10-dione. Based on the guideline values available for human consumption, no mussels exceeded the limits. No differences could be seen between wild and cultivated mussels. To sum up, PAHs were found in mussels, but not at such concentration that the mussels would not be approved for human consumption.
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Petry, Thomas. "Human exposure to airborne polycyclic aromatic hydrocarbons (PAHs) /." [S.l.] : [s.n.], 1994. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10726.

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Bukvic, Anamaria. "Phytoremediation of Metals and PAHs Occurring as Mixtures." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1016463095.

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Books on the topic "PAHs"

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Neilson, Alasdair H., ed. PAHs and Related Compounds. Berlin, Heidelberg: Springer Berlin Heidelberg, 1998. http://dx.doi.org/10.1007/978-3-540-49697-7.

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Douben, Peter E. T., ed. PAHs: An Ecotoxicological Perspective. Chichester, UK: John Wiley & Sons, Ltd, 2003. http://dx.doi.org/10.1002/0470867132.

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name, No. PAHs: An ecotoxicological perspective. Chichester: John Wiley, 2003.

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T, Douben Peter E., ed. PAHs: An ecotoxicological perspective. Chichester, England: Wiley, 2003.

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United States. Agency for Toxic Substances and Disease Registry. Division of Toxicology. Polycyclic aromatic hydrocarbons (PAHs). Atlanta, GA: Agency for Toxic Substances Disease Registry, Division of Toxicology, Dept. of Health and Human Services, Public Health Service, 1995.

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Beasley, Gary. Macroinvertebrates, heavy metals and PAHs in urban watercourses. Leeds: University of Leeds, School of Geography, 2001.

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V, Zitko. PAHs in Saint John Harbour sediments: An evaluation of 1996-1999 results. St. Andrews, N.B: Fisheries and Oceans, 1999.

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Evans, Karen. The source, composition and fate of selected PAHs in the River Derwent, Derbyshire, and in associated biota. [Derby: Derbyshire College of Higher Education], 1990.

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Johnson, Lyndal L. An analysis in support of sediment quality thresholds for polycyclic aromatic hydrocarbons (PAHs) to protect estuarine fish. [Seattle, Wash.]: U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, [Northwest Fisheries Science Center, 2001.

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Johnson, Art. Concentrations of 303(d) listed pesticides, PCBs and PAHs measured with passive samplers deployed in the lower Columbia River. Olympia, Washington: Washington State Department of Ecology, 2005.

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Book chapters on the topic "PAHs"

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Tang, Ning. "PAHs/NPAHs." In Polycyclic Aromatic Hydrocarbons, 29–39. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-6775-4_3.

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Allamandola, L. J. "PAHs, They’re Everywhere!" In The Cosmic Dust Connection, 81–102. Dordrecht: Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-011-5652-3_4.

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Srivastav, Ajeet K., Shikha Agnihotry, Syed Faiz Mujtaba, Sandeep Negi, Ankit Verma, and Ratan Singh Ray. "PAHs and Phototoxicity." In Photocarcinogenesis & Photoprotection, 85–99. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-5493-8_9.

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Agteren, Martin H., Sytze Keuning, and Dick B. Janssen. "Polyaromatic hydrocarbons (PAHs)." In Environment & Chemistry, 287–349. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-015-9062-4_5.

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Kasai, Yuki, and Shigeaki Harayama. "Catabolism of PAHS." In Pseudomonas, 463–90. Boston, MA: Springer US, 2004. http://dx.doi.org/10.1007/978-1-4419-9088-4_16.

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Tielens, A. G. G. M. "Interstellar PAHs and Dust." In Planets, Stars and Stellar Systems, 499–548. Dordrecht: Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-5612-0_10.

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Zander, Maximilian. "PAHs im Interstellaren Raum." In Teubner Studienbücher Chemie, 234. Wiesbaden: Vieweg+Teubner Verlag, 1995. http://dx.doi.org/10.1007/978-3-322-96707-7_10.

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Harvey, Ronald G. "Environmental Chemistry of PAHs." In The Handbook of Environmental Chemistry, 1–54. Berlin, Heidelberg: Springer Berlin Heidelberg, 1998. http://dx.doi.org/10.1007/978-3-540-49697-7_1.

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Tielens, A. G. G. M., and E. Peeters. "Spectroscopy of Interstellar PAHs." In Springer Proceedings in Physics, 497–506. Berlin, Heidelberg: Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-18902-9_88.

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Shen, Guofeng. "Nitro- and Oxygenated PAHs." In Emission Factors of Carbonaceous Particulate Matter and Polycyclic Aromatic Hydrocarbons from Residential Solid Fuel Combustions, 139–61. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-39762-2_6.

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Conference papers on the topic "PAHs"

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Di Domenico, Massimiliano, Peter Gerlinger, and Manfred Aigner. "Numerical Investigation of Soot Formation in Laminar Ethylene-Air Diffusion Flames." In ASME Turbo Expo 2007: Power for Land, Sea, and Air. ASMEDC, 2007. http://dx.doi.org/10.1115/gt2007-27118.

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In this work a new soot formation model is used to predict temperature, species and soot concentrations in laminar ethylene-air diffusion flames. The gas-phase chemistry is described by elementary reactions with transport equations solved for any species. The chemical paths yielding to soot are modeled by a sectional approach for Polycyclic Aromatic Hydrocarbons (PAHs). Soot dynamics is described by a two-equation model for soot mass fraction and particle number density. Phenomena like nucleation, growth and oxidation have been included both for PAHs and soot. Moreover, PAH-PAH and PAH-soot collisions are taken into account. Species, PAH and soot transport equations are implemented in the in-house DLR-THETA CFD code. The laminar, ethylene-air diffusion flame investigated experimentally by McEnally and coworkers (2000) is simulated in order to validate the model. An analysis of the main flame’s features as well as the interaction between them and the soot chemistry will be given. A qualitative correlation between local stoichiometric values and soot formation rate is assessed. In order to study the sensitivity of the combustion model to simulation parameters like the inlet temperature and kinetic mechanism, additional simulations are performed. Results are also compared with experimental data in terms of temperature, species mole fractions and soot volume fraction axial profiles.
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Paniz, Evelyn, Luciano Pivoto Specht, Deividi S. Pereira, Luis M. R. Ferraz, Paulo Cícero Nascimento, and Francisco Thiago Sacramento Aragao. "PAHs emissions by Brazilian bitumens." In 6th Eurasphalt & Eurobitume Congress. Czech Technical University in Prague, 2016. http://dx.doi.org/10.14311/ee.2016.245.

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Semenikhin, A. S., A. S. Savchenkova, I. V. Chechet, S. G. Matveev, I. A. Zubrin, M. Frenklach, and A. M. Mebel. "REACTIONS OF TRANSFORMATION OF THE FIVE-MEMBERED RING OF CYCLOPENTAPHENANTHRENE UPON INTERACTION WITH ACETYLENE: A THEORETICAL STUDY." In 9TH INTERNATIONAL SYMPOSIUM ON NONEQUILIBRIUM PROCESSES, PLASMA, COMBUSTION, AND ATMOSPHERIC PHENOMENA. TORUS PRESS, 2020. http://dx.doi.org/10.30826/nepcap9a-10.

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Reducing emissions of carcinogenic polycyclic aromatic hydrocarbons (PAHs) and the smoke number at the stage of designing and improving of combustion chambers is an urgent engineering and environmental task that requires improvement of the currently used predictive combustion models. The submechanisms describing the growth of PAHs in such models are incomplete and valid only in a narrow range of initial conditions. Further refinement of the kinetics of PAH and soot formation is associated with the need for more theoretical and experimental studies.
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Eigentler, Florian, Peter Gerlinger, Manfred Aigner, and Ruud Eggels. "Development and Application of a Reversible PAH Formation Model for Soot Prediction in Complex Fuel CFD Applications." In ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-14692.

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Abstract An improved modelling approach for polycyclic aromatic hydrocarbons (PAHs) and soot formation in complex fuels is presented. The introduction of PAH radicals allows a reversible growth by hydrogen abstraction and carbon addition. Emphasis is placed on the model’s general validity with respect to fuel flexibility and operating condition using one set of model constants. A detailed gas phase mechanism describes the decomposition of fuel species as well as the formation and growth of PAHs and soot precursors. PAHs and PAH radicals are described by a sectional approach. Soot particle dynamics are modeled either by a two-equation model or alternatively by a sectional approach. All models take the processes of growth, collision, oxidation and agglomeration into account. The introduction of a temperature-dependent collision coefficient enhances the PAH and soot interaction. The differences between the two-equation model and the sectional approach are investigated. An extensive set of shock tube experiments is examined to verify the developed PAH and soot model over a wide range of temperatures, pressures, fuels and mixing-ratios. Thereby, the pyrolysis and oxidation of ethylene, benzene, kerosene and its major components are examined. In addition, ignition delay times and laminar diffusion flames are used for further validation. The overall agreement to experimental data demonstrates the applicability of the presented PAH and soot model even for complex fuels.
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Saika, Tatsuya, Youhei Sakita, and Masahiko Shibahara. "The Effect of the Residence Time in the High Temperature Field on the Fullerene and PAH Formation Mechanism." In ASME/JSME 2011 8th Thermal Engineering Joint Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajtec2011-44543.

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Fullerenes were generated and observed in the combustion processes of hydrocarbon fuel under reduced pressure conditions however the fullerene formation mechanism from PAHs in fuel rich hydrocarbon flames under reduced pressure conditions has not been clarified yet. In the present study, the effects of the residence time in the high temperature reaction field were investigated experimentally and the effects of the residence time on the contents of fullerenes and PAHs were discussed. The experimental results showed that the contents of fullerenes as well as PAHs in the total soot collected from the flue gas decreased with the increase of the residence time in the range from 800 to 1500 degree Celsius. On the other hand, the contents of fullerenes in the total soot decreased with the increase of the residence time over 1500 degree Celsius because the total PAHs contents in the flue gas increased under the present experimental conditions. It is essential for the fullerene generation to realize the optimal residence time from 800 to 1500 degree Celsius as well as that over 1500 degree Celsius with an appropriate PAH partial pressure in the combustion process.
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Kamalova, A., P. Galitskaya, A. Gordeev, A. Khamieva, and P. Kuryntseva. "COMPARATIVE STUDY OF EXTRACTION METHODS FOR THE DETERMINATION OF PAHS IN SOILS USING GC-MS." In 23rd SGEM International Multidisciplinary Scientific GeoConference 2023. STEF92 Technology, 2023. http://dx.doi.org/10.5593/sgem2023/5.1/s20.11.

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Soil contamination by polycyclic aromatic hydrocarbons (PAHs) is a widespread concern due to the high potential for human exposure through inhalation, ingestion, and dermal contact. In this study, we compared the efficiency of three different methods for PAHs extraction from model samples, including ultrasonic (US), mechanical shaking and purification with commercial QuEChERS kit (Shq), and ultrasonic extraction coupled with QuEChERS (USq) by gas chromatography coupled to a triple quadrupole tandem mass-spectrometry (GC-MS). The results showed that in the ultrasonic extraction with subsequent purification using QuEChERS, the content of PAHs in the sample varied from 86.91 to 2211.60 ng/g. Whereas, in mechanical shaking method, this range was in the range 1.56-761.20 ng/g. In the case of ultrasonic extraction without sorbent purification, only for acenaphthene, fluorene, and benzo(g,h,i)perylene, the values were higher compared to the other two methods: 285.78�27.56 ng/g, 577.48�73.62 ng/g, and 266.35�177.30 ng/g, respectively. The comparison of PAH extraction efficiency showed that the combination of ultrasonic extraction and purification with QuEChERS (USq) was the most efficient method and rapid, obtaining the highest yields for all tested PAHs.
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Karavalakis, George, Stamoulis Stournas, George Fontaras, Zissis Samaras, George Dedes, and Evangelos Bakeas. "The Effect of Biodiesel on PAHs, Nitro-PAHs and Oxy-PAHs Emissions from a Light Vehicle Operated Over the European and the Artemis Driving Cycles." In Powertrains, Fuels and Lubricants Meeting. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2009. http://dx.doi.org/10.4271/2009-01-1895.

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Zhou, Hongcang, Baosheng Jin, Zhaoping Zhong, Rui Xiao, and Yaji Huang. "Profiles and TEQ Concentrations of PAHs Emission From Fluidized Bed Coal Gasification." In 18th International Conference on Fluidized Bed Combustion. ASMEDC, 2005. http://dx.doi.org/10.1115/fbc2005-78007.

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More growing particular attentions are being paid to polycyclic aromatic hydrocarbons (PAHs) generated from coal gasification due to their high mutagenic and carcinogenic. Fluidized bed air and steam gasification of three different rank coals were studied in a bench-scale atmospheric fluidized bed test facility. An extraction and high performance liquid chromatography (HPLC) technique was used to analyze the concentrations of the 16 PAHs specified by US EPA in raw coal, slag, bag house char, cyclone char and fuel gas. The profiles and TEQ concentrations of PAHs emission from fluidized bed coal gasification were discussed. The results indicated that there were mainly three- and four-ringed PAHs in raw coal and fuel gas, but the total PAHs in bag house char and cyclone char were dominated by three-, four- and five-ringed PAHs. The concentrations of three-ringed PAHs in fuel gas were higher than those of four-ringed PAHs, but a reverse phenomenon occurred in bag house char and cyclone char. No PAHs were measured in slag during coal gasification. The total TEQ concentration of five-ringed PAHs mainly dominated in raw coal, fuel gas, bag house char, and cyclone char, and their percentages were about 75–96% by weight. Benzo(a)pyrene (BaP) was the main contributor of TEQ concentration in raw coal and gasified products. In addition, the concentration of PAHs in raw coal increased with the rise of coal rank, and there was not an obvious variation about the concentration of PAHs in gasified products.
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Katta, Viswanath R., and William M. Roquemore. "Simulation of PAHs in Trapped-Vortex Combustor." In ASME Turbo Expo 2004: Power for Land, Sea, and Air. ASMEDC, 2004. http://dx.doi.org/10.1115/gt2004-54165.

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Residence time and thermo-chemical environment are important factors in determining soot-formation characteristics of jet engine combustors. For understanding the chemical and physical structure of the soot formed in these combustors knowledge on flow dynamics and formation of polycyclic aromatics-hydrocarbons (PAHs) is required. A time-dependent, detailed-chemistry computational-fluid-dynamic (CFD) model is developed for the simulation of the reacting flows in a trapped-vortex combustor. The axisymmetric trapped-vortex combustor of Hsu et al. was modeled by replacing injection holes with injection slots. Ethylene-air mixtures were used as fuel. Several calculations were made by varying the equivalence ratio and velocity of the main flow. Unsteady simulations revealed that the shearlayer vortices established outside the cavity flow enhance mixing of benzene in the wake region of the afterbody. However, in all the cases considered here, majority of the PAH species are produced in the cavity region. While fuel-rich condition resulted lower amounts of PAHs in the cavity region, soot is produced more in this region.
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Blokker, Mirjam, and Nellie Slaats. "PAHs in Coated Cast Iron Mains." In World Environmental and Water Resources Congress 2013. Reston, VA: American Society of Civil Engineers, 2013. http://dx.doi.org/10.1061/9780784412947.084.

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Reports on the topic "PAHs"

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Huncik, Kevin M., John Kucklick, and Jared M. Ragland. Polycyclic aromatic hydrocarbons (PAHs) in marine mammal blubber:. Gaithersburg, MD: National Institute of Standards and Technology, March 2019. http://dx.doi.org/10.6028/nist.ir.8233.

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Mamantov, G., and E. L. Wehry. Sorption and chemical transformation of PAHs on coal fly ash. Office of Scientific and Technical Information (OSTI), January 1992. http://dx.doi.org/10.2172/7104665.

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Atanassova, Irena, Milena Harizanova, and Matrin Banov. Labile Polycyclic Aromatic Hydrocarbons (PAHs) in Fly Ash Reclaimed Technosols. "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences, October 2019. http://dx.doi.org/10.7546/crabs.2019.10.18.

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Carman, Kevin R., John W. Fleeger, Robert P. Gambrell, and Ralph J. Portier. Interactive Effects of Metals and PAHs on Benthic Food Webs. Fort Belvoir, VA: Defense Technical Information Center, August 2001. http://dx.doi.org/10.21236/ada628034.

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Carman, Kevin R., John W. Fleeger, Robert P. Gambrell, and Ralph J. Portier. Interactive Effects of Metals and PAHs on Benthic Food Webs. Fort Belvoir, VA: Defense Technical Information Center, September 1999. http://dx.doi.org/10.21236/ada631614.

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Kobayashi, Yoshihiro, Kenji Amagai, and Masataka Arai. PAHs Measurement in a Laminar Diffusion Flame of Diesel Fuel. Warrendale, PA: SAE International, May 2005. http://dx.doi.org/10.4271/2005-08-0163.

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Mamantov, G., and E. L. Wehry. Sorption and chemical transformation of PAHs on coal fly ash. Office of Scientific and Technical Information (OSTI), January 1991. http://dx.doi.org/10.2172/5805425.

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Mamantov, G., and E. L. Wehry. Sorption and chemical transformation of PAHs on coal fly ash. Office of Scientific and Technical Information (OSTI), January 1992. http://dx.doi.org/10.2172/6815920.

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9

Carman, Kevin R., John W. Fleeger, Robert P. Gambrell, and Ralph J. Portier. Interactive Effects of Metals and PAHs on Benthic Food Webs. Fort Belvoir, VA: Defense Technical Information Center, September 2002. http://dx.doi.org/10.21236/ada621135.

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Borole, A. P., B. H. Davison, and T. Kuritz. Enzymatic Upgrading of Heavy Crudes via Partial Oxidation or Conversion of PAHs. Office of Scientific and Technical Information (OSTI), July 2002. http://dx.doi.org/10.2172/940405.

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