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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
Sat Jan 31 2015
Journal Name
Journal Of Al-qadisiyah For Pure Science
synthesis ,spectral studies and antimicrobial evalution of 6,6-(1,2-benzenediazo)bis(3-amino benzoic acid) complexes with some metal ions
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Publication Date
Wed Dec 31 2025
Journal Name
Iraqi National Journal Of Earth Science (injes)
Overpressure and Under-Compaction Mechanism Effect on Pore and Fracture Pressure Development of Mauddud Formation, Badra Oil Field, Eastern Iraq
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Accurate pore and fracture pressure detection is a major step in successful drilling operations design. The overestimation of these parameters absolutely leads to serious problems throughout and after well drilling. This study is concerned with the characterization and analysis of the most significant diagenetic processes that degrade or improve the reservoir characteristics of the Mauddud Formation in the Badra oil field. The primary goal of this research is to estimate the pore pressure and fracture pressure using well logging data by Techlog 2015 software in order to assess the impact on the estimation of the mud weight window (MWW). The estimated values of formation pressures are then analyzed according to different diagenetic p

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Publication Date
Sun Jan 02 2022
Journal Name
Journal Of The College Of Languages (jcl)
Pragmatics and Speech Act- History, Importance and Stages of Development: הפרגמטיקה ופעולת־הדיבור- התולדות, החשיבות ושלבי ההתפתחות (יישמוים בלשון העברית)
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      The present study stresses two of the most significant aspects of linguistic approach: Pragmatics” and the “Speech Act Theory”, revealing its importance and the stages and levels of development through Hebrew language’s speech acts analysis including (political speech, the Holy Bible, Hebrew stories).

       Chronologically, Pragmatics has always been the center of linguists’ interests due to its importance in linguistic decryptions, particularly, through “Speech Act Theory” that has been initiated and developed by the most prominent philosophers and linguistics.

        The prese

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Publication Date
Sun Apr 27 2025
Journal Name
Al-rafidain Journal Of Medical Sciences ( Issn 2789-3219 )
CD40 Gene Variants and Disease Susceptibility: A Comprehensive Review of Associations with Immune-Mediated Inflammatory Diseases, Cancer, and Infectious Diseases
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CD40 is a type 1 transmembrane protein composed of 277 amino acids, and it belongs to the tumor necrosis factor receptor (TNFR) superfamily. It is expressed in a variety of cell types, including normal B cells, macrophages, dendritic cells, and endothelial cells, as a costimulatory molecule. This study aims to summarize the CD40 polymorphism effect and its susceptibility to immune-related disorders. The CD40 gene polymorphisms showed a significant association with different immune-related disorders and act as a risk factor for increased susceptibility to these diseases.

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Publication Date
Sun Nov 10 2019
Journal Name
Journal Of Engineering And Applied Sciences
Fabrication and Properties of Ag<sub>2</sub>O/Si Heterojunction Solar Cell Pure and Doped (Sb, Sn and Se)
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Publication Date
Fri Jan 13 2023
Journal Name
Journal Of Research In Medical And Dental Science
Phytochemical Screening and Antibacterial Effect of Stevia Rebaudiana (Bertoni) Alcoholic Leaves Extract on Streptococcus Oralis (Dental Plaque’s Primary Colonizer)
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Phytochemical Screening and Antibacterial Effect of Stevia Rebaudiana (Bertoni) Alcoholic Leaves Extract on Streptococcus Oralis (Dental Plaque’s Primary Colonizer), Manar Ibrahim

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Publication Date
Mon Aug 28 2023
Journal Name
Journal Of Planner And Development
Estimation of urban land price within holly cities by using integrated GIS-regression models: case study Al-Kufa city- Iraq
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        Urban land price is the primary indicator of land development in urban areas. Land prices in holly cities have rapidly increased due to tourism and religious activities. Public agencies are usually facing challenges in managing land prices in religious areas. Therefore, they require developed models or tools to understand land prices within religious cities. Predicting land prices can efficiently retain future management and develop urban lands within religious cities. This study proposed a new methodology to predict urban land prices within holy cities. The methodology is based on two models, Linear Regression (LR) and Support Vector Regression (SVR), and nine variables (land price, land area,

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Publication Date
Mon Mar 01 2021
Journal Name
Journal Of Physics: Conference Series
Structural, surface morphology and optical properties of annealing treated Copper Phthalocyanine doped Fullerene (CuPc: C<sub>60</sub>) thin films
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Abstract<p>The doping process with materials related to carbon has become a newly emerged approach for achieving an improvement in different physical properties for the obtained doped films. Thin films of CuPc: C<sub>60</sub> with doping ratio of (100:1) were spin-coated onto pre-cleaned glass substrates at room temperature. The prepared films were annealed at different temperatures of (373, 423 and 473) K. The structural studies, using a specific diffractometry of annealed and as deposited samples showed a polymorphism structure and dominated by CuPc with preferential orientation of the plane (100) of (2θ = 7) except at temperature of 423K which indicated a small peak around (2θ = 3</p> ... Show More
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Publication Date
Thu May 17 2012
Journal Name
Baghdad Science Journal
Synthesis and Spectral Studies of ZnII,CdII and HgII Complexes with 5-(2-Benzoic acid azo)-8-hydroxy quinoline Ligand
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Coupling reaction of 2-amino benzoic acid with 8-hydroxy quinoline gave bidentate azo ligand. The prepared ligand has been identified by Microelemental Analysis,1HNMR,FT-IR and UV-Vis spectroscopic techniques. Treatment of the prepared ligand with the following metal ions (ZnII,CdII and HgII) in aqueous ethanol with a 1:2 M:L ratio and at optimum pH, yielded a series of neutral complexes of the general formula [M(L)2]. The prepared complexes have been characterized by using flame atomic absorption, (C.H.N) Analysis, FT-IR and UV-Vis spectroscopic methods as well as conductivity measurements. The nature of the complexes formed were studied following the mole ratio and continuous variation methods, Beer's law obeyed over a concentration range

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Publication Date
Tue Sep 01 2015
Journal Name
Photomedicine And Laser Surgery
Evaluation of Temperature Elevation During Root Canal Treatment with Dual Wavelength Laser: 2780 nm Er,Cr:YSGG and 940 nm Diode
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