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The spatial extent of polycyclic aromatic hydrocarbons emission in the Herbig star HD 179218
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Aim. We investigate, in the mid-infrared, the spatial properties of the polycyclic aromatic hydrocarbons (PAHs) emission in the disk of HD 179218, an intermediate-mass Herbig star at ~300 pc.

Methods. We obtained mid-infrared images in the PAH-1, PAH-2 and Si-6 filters centered at 8.6, 11.3, and 12.5 μm, and N-band low-resolution spectra using CanariCam on the 10-m Gran Telescopio Canarias (GTC). We compared the point spread function (PSF) profiles measured in the PAH filters to the profile derived in the Si-6 filter, where the thermal continuum emission dominates. We performed radiative transfer modeling of the spectral energy distribution (SED) and produced synthetic images in the three filters to investigate different spatial scenarios.

Results. Our data show that the disk emission is spatially resolved in the PAH-1 and PAH-2 filters, while unresolved in the Si-6 filter. Thanks to very good observing conditions, an average full width at half maximum (FWHM) of 0.232′′, 0.280′′ and 0.293′′ is measured in the three filters, respectively. Gaussian disk fitting and quadratic subtraction of the science and calibrator PSFs suggests a lower-limit characteristic angular diameter of the emission of ~100 mas, or ~30 au. The photometric and spectroscopic results are compatible with previous findings. Our radiative transfer (RT) modeling of the continuum suggests that the resolved emission should result from PAH molecules on the disk atmosphere being UV-excited by the central star. Simple geometrical models of the PAH component compared to the underlying continuum point to a PAH emission uniformly extended out to the physical limits of the disk model. Furthermore, our RT best model of the continuum requires a negative exponent of the surface density power-law, in contrast with earlier modeling pointing to a positive exponent.

Conclusions. We have spatially resolved – for the first time to our knowledge – the PAHs emission in the disk of HD 179218 and set constraints on its spatial extent. Based on spatial and spectroscopic considerations as well as on qualitative comparison with IRS 48 and HD 97048, we favor a scenario in which PAHs extend out to large radii across the flared disk surface and are at the same time predominantly in an ionized charge state due to the strong UV radiation field of the 180 L central star.

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Publication Date
Sun Dec 29 2019
Journal Name
Iraqi Journal Of Science
Distribution of Polycyclic Aromatic Hydrocarbons in Water and Sediments in the Euphrates River, Iraq
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The monitoring of lotic ecosystems is important for environmental health after war crisis. This study aimed to detect the fate of the sixteen polycyclic aromatic hydrocarbon compounds (PAHs) as priority pollutants in the water and sediment of Al-Hussainya River in Karbala Province. The results indicated that the concentrations in water samples ranged from 0.24–58.72 ηg.L-1 for each of the benzo(a) pyrene and benzo(g, h, i)perylene. The concentrations in sediment samples have been observed to be in a range of 0.36–119.06 μg.g-1 for naphthalene and benzo(g,h,i)perylene. Benzo(g,h,i)perylene recorded the highest concentrations in each of water and sediment samples as compared with the other compound

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Publication Date
Wed Feb 22 2023
Journal Name
Iraqi Journal Of Science
Health Risk Assessment of Polycyclic Aromatic Hydrocarbons in Surface Soils at North Baiji City, Iraq.
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Four major factories (Petroleum Refineries Company, Detergents Plant, Thermal Power Plant, and Gaseous Power Plant) are located to the north of Baiji City. They release pollutants in form of gases, liquids and solids; they find their way to the surrounding environment. To assess the environmental pollution of the area, 18 samples of surface soil distributed around the industrial establishments were collected and analyzed to determine the concentration of polycyclic aromatic hydrocarbons (PAH) components which are often targets in the environmental checking. Identification and quantification of the 16 PAHs components was accomplished using High Performance Liquid Chromatography (HPLC) had a model Shimadzu LC-10 AVP. The total concentratio

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Publication Date
Thu Apr 29 2021
Journal Name
Iraqi Journal Of Science
Speculative Carcinogenicity Assessment of Polycyclic Aromatic Hydrocarbons Found in Some Anti-Diarrheal Herbal Drugs Sold in Ondo State of Nigeria
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The conviction that herbal drugs have enormous health benefits has led to increase the rate of their consumption by Nigerians. The aim of this study was to assess the carcinogenic property of some popularly consumed anti-diarrheal herbal drugs via polycyclic aromatic hydrocarbons (PAHs) quantification. Three prevalent anti-diarrhea herbal drugs , Odunmo herbal drug (Hibiscus rosa-sinensis and Bacopamonnieri), Orogun herbal mixture (Hibiscus sabdariffaI and Hedera helix), and Alora herbal syrup (Aloe vera and Hibiscus sabdariffaI) were bought for the purpose of this study and they were coded as samples A, B, and C, respectively. The ultrasonic extraction of the herbal drugs was carried

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Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
Evaluation of the Organic-Pollution Based on the Determination of some Polycyclic Aromatic Hydrocarbons(PAHs) in Tigris River Water in 2012 at Baghdad City , Iraq
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This study aims to predict the organic pollution produced from the presence of some polycyclic aromatic hydrocarbons (PAHs) and determination it's concentrations (µg/L , ppb) in Tigris river water by a collection twenty-seven water samples from a selected three stations with nine sampling sites and three depths of water (5 cm , 2 m and 4 m) each site for 4.6 km distance of a geographic studied area which is located between the ( Al-Senak and AL-Sarrafiah bridges ) at Baghdad city – Iraq on May, 2012. The geographic location was determined with a Global Positioning System (GPS) and Geographic Information System (GIS) software program. The concentrations of fourteen components (PAHs) were performed using the reverse phase

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Publication Date
Sun Apr 30 2023
Journal Name
Iraqi Journal Of Science
Determination of Polycyclic Aromatic Hydrocarbon (PAHs) in the Tigris River through Passing Baghdad Province
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Tigris River receives many pollutants while passing through Baghdad province due to increasing of population, discharge of untreated industrials, agricultural wastes on the river. The present study was conducted from January 2013 to December 2013 on the Tigris River starting from Al-Muthana Bridge to Al-Zaufurania city before it's jointed with Diyalla Tributaries. Six stations were chosen on the Tigris River along Baghdad city. The study was included measuring the bimonthly concentrations and distributions of polycyclic aromatic hydrocarbons (PAHs) in the samples of surface water. The sixteen polycyclic aromatic hydrocarbons (PAHs) listed by USEPA as priority pollutants (Naphthalene, Acenaphthalene, Acenaphthene, Fluorene, Phenanthrene,

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Publication Date
Sun Oct 22 2023
Journal Name
Iraqi Journal Of Science
Environmental Assessment of Polycyclic Aromatic Hydrocarbon Concentrations in Atmospheric Air at Daura Refinery
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Polycyclic aromatic hydrocarbons (PAHs) were measured in aerosol from air samples, which collected for the period from April 2012 to February 2013, in Baghdad city, at Daura Refinery. Aerosol samples were collected on cellulose fiber filters for 1.5 h in each site for the morning and evening time. These aerosol samples undergone soxhlet extraction.
After the extraction, 49 samples were analyzed by GC-MS in order to determin 16 PAH compounds. The parameters temperature, relative humidity and wind speed were measured during the measurement period. The PAH concentrations were different for location inside and outside Daura refinery. Naphthalene was the most abundant PAH detected in all points at the site sampling for all seasons. There i

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Publication Date
Thu Jun 01 2023
Journal Name
Baghdad Science Journal
Concentrations, Sources and Distribution of Polycyclic Aromatic Hydrocarbon (PAHs) Compounds in Basrah soils, Iraq
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  Anthropogenic activities cause soil pollution with different serious pollutants, such as polycyclic aromatic hydrocarbon (PAHs) compounds. This study assessed the contamination of PAHs in soil samples collected from 30 sites divided into eight groups (residential areas, oil areas, agricultural areas, roads, petrol stations, power plants, public parks and electrical generators) in Basrah city-Iraq during 2019-2020. The soil characteristics including (moisture, pH, EC and TOC) were measured. Results showed the following ranges (soil moisture (0.03-0.18%),pH (6.90-8.16), EC (2.48-104.80) mS/cm and TOC (9.90-20.50%)). Gas Chromatography (GC) was used to measure PAHs in extracted soil samples. The total PAH range (499.96 - 5864.86) ng/g dr

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Publication Date
Tue Mar 31 2015
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Extraction of Aromatic Hydrocarbons from Lube Oil Using Different Co-Solvent
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An investigation was conducted effect of addition co- solvent on solvent extraction process for two types of a lubricating oil fraction (spindle) and (SAE-30) obtained from vacuum distillation unit of lube oil plant of Daura Refinery. In this study two types of co-solvents ( formamide and N-methyl, 2, pyrrolidone) were blended with furfural to extract aromatic hydrocarbons which are the undesirable materials in raw lubricating oil, in order to improve the viscosity index, viscosity and yield of produced lubricating oil. The studied operating condition are extraction temperature range from 70 to 110 °C for formamide and 80 to 120 °C for N-methyl, 2, pyrrolidone, solvent to oil ratio range from 1:1 to 2:1 (wt./wt.) for furfural with form

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Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
Detection and Removal of Polycyclic Aromatic Hydrocarbon from Selected Areas in Tigris River in Baghdad City
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Aromatic hydrocarbons present in Iraqi national surface water were believed to be raised principally from combustion of various petroleum products, industrial processes and transport output and their precipitation on surface water.
Polycyclic aromatic hydrocarbons (PAHs) were included in the priority pollutant list due to their toxic and carcinogenic nature. The concern about water contamination and the consequent human exposure have encouraged the development of new methods for
PAHs detection and removal.
PAHs, the real contaminants of petroleum matter, were detected in selected sites along Tigris River within Baghdad City in summer and winter time, using Shimadzu high performance liquid chromatography (HPLC) system.
Analysi

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Publication Date
Tue Sep 30 2014
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Environmental Assessment of Polycyclic Aromatic Hydrocarbon Concentrations in Air at Thermal South Power Station of Baghdad
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Sixteen polycyclic aromatic hydrocarbons (PAHs) concentrations were measured in aerosol samples collected for the period from April 2012 to February 2013 at thermal south power station of Baghdad. Fourty one aerosol sample were extracted with (1:1) dichloromethane and methanol using soxhlet for seventeen hour. The extraction solution was analyzed applying GC/MS. The PAH concentrations outside thermal south power station were higher than those inside it, and higher in summer season than in winter. Naphthalene, pyrene, Anthracene, Indeno [1, 2, 3-cd] pyrene and Phenanthrene were the most abundant PAHs detected in all points at the site sampling. The total polycyclic aromatic hydrocarbon (TPAH) and total suspended particles (TSP) concentrat

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