Preferred Language
Articles
/
WhZYU4cBVTCNdQwCdEU-
The spatial extent of polycyclic aromatic hydrocarbons emission in the Herbig star HD 179218
...Show More Authors

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.

Scopus Clarivate Crossref
View Publication
Publication Date
Sun Oct 01 2017
Journal Name
Journal Of Educational And Psychological Researches
The Extent of Teachers' Application of Professional Standards from the Point of view of Educational Supervisors
...Show More Authors

This study aimed to identify the extent of teachers' application of professional standards from the point of view of supervisors and detecting differences in the means of their estimates that may be attributed to the variables of the study (sex, number of years of service, educational qualification).The study adopted a descriptive approach. In order to achieve the aims of the study, a questionnaire including four areas, namely: (professional features, academic knowledge and pedagogy, teaching and learning, and professional development) was constructed.

The questionnaire was applied to a population which consisted of 60 supervisors of all school subjects in the Directorates of Education in

... Show More
View Publication Preview PDF
Publication Date
Tue Dec 15 2020
Journal Name
Al-academy
Spatial Formation of the Sculptural Body in the Space of the Theatrical Show: عقيل ماجد حامد محمد الملاحسن
...Show More Authors

The current research presents a study of the sculptural body in the space of the theatrical show through reviewing most of the ideas, propositions and workings presented by philosophers and directors within the space of the show, that there were various experiences of employing those spatial formations through the mediator (the space) based on sculpturing the body in achieving those formations, which contributed in building a symbolic picture of various structural connotations. That was formulated through the research chapters, which include the first chapter (the methodological framework) which consists of two sections. The first section (the duality of space formation and imaginations). The second section (sculptural body sequences in

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Oct 01 2022
Journal Name
Al–bahith Al–a'alami
THE EXTENT OF EXPOSURE OF BAGHDAD UNIVERSITY : (Students To Cultural And Television Programs)
...Show More Authors

Communication is one of the main elements of culture, it is the source of its formation and a factor of its development and spread. Communication is a 'dynamic' cultural process and is an integral part of the political, social, economic and cultural aspects of people. Therefore, mass communication means help in the course and movement of individuals and cultural communities. The relationship between media and culture according to this perspective is one of many key factors and influential forces that make it coherent and sometimes intertwined. It is a problematic relationship that leads to research and study in order to lay the right foundations in the orientation towards the audience.

Mass communication has many basic functions.

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Jun 30 2016
Journal Name
European Journal Of Chemistry
Reaction paths and transition states of the C-C and C-H bond cleavage in the aromatic anthracene and phenanthrene molecules
...Show More Authors

The reaction paths of the C-C and C-H bond cleavage in the anthracene and phenanthrene aromatic molecules are studied by applying the ab-initio DFT method. It is found that the C-C bond cleavage proceeds via a singlet aromatic transition state, compelled through a disrotatoric ring opening reaction. A suprafacial H atom shift follows the transition state, leading to the formation of a methylene -CH2 and an acetylenic or allenic moiety. The calculated activation energies for anthracene range from 158.81-208.90 kcal/mol and the reaction energies from 96.106-156.976 kcal/mol. For phenanthrene, the energy values are 157.39-202.34 kcal/mol and 62.639-182.423 kcal/mol, respectively. For the C-H cleavage reactions, the calculated reaction energies

... Show More
View Publication
Crossref (2)
Crossref
Publication Date
Mon May 01 2023
Journal Name
Journal Of Molecular Liquids
On the influence of hydrocarbons solvents on the inhibition efficiency of some organic corrosion inhibitors: Theoretical and validation studies
...Show More Authors

View Publication
Scopus (10)
Crossref (11)
Scopus Clarivate Crossref
Publication Date
Thu Sep 01 2022
Journal Name
Iraqi Journal Of Physics
X-Ray Emission Spectroscopy Analysis for Near-Asteroid Belt of Atmospheric of the Comets
...Show More Authors

         According to Chandra Survey Observatory Near-Asteroid Belt Comets, the solar wind's contact with the comet produces a variety of spectral characteristics. The study of X-ray spectra produced by charge exchange is presented here. The spectrum of a comet can reveal a lot about its composition. This study has concentrated on the elemental abundance in six different comets, including 17P/Holmes, C/1999T1, C/2013A1, 9p/Temple1, and 103p/Hartley2 (NEAT). Numerous aspects of the comet's dynamics allow it to behave in a unique manner as it gets closer to the Near-Asteroid Belt. These characteristics are being examined, and some studies are still ongoing. The computations allow us to observe, for instance, how the composition of

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Jun 21 2022
Journal Name
Journal Of Planner And Development
Spatial analysis of primary and secondary education se rvices in the city of Ramadi
...Show More Authors

The researchers aim of this research to analyze the reality of educational services in the city of Ramadi in order to reveal the efficiency of the spatial distribution of schools at the level of residential neighborhoods and the requirements of the population, based on the standards and indicators for this service.

The research problem related to the educational function of the city of Ramadi was formulated by asking about the efficiency of the spatial distribution of educational services and whether there is a balance in the distribution of schools to residential neighborhoods in a way that meets the requirements of the population, and in order to answer the research problem, the research hypothesis was formulated that there is

... Show More
View Publication Preview PDF
Publication Date
Thu Jan 10 2019
Journal Name
Journal Of The College Of Education For Women
Spatial analysis of population growth in the district of Tuz Khurmatu for (1977-2012)
...Show More Authors

The study population growth of the most important demographic phenomena upon which planners to meet changes in the size of the population increase is through knowledge of the requirements of population growth can be planned for the future. On this basis, Tuz District was chosen for the study of population growth, which set her period (1977-2012), and compared with the growth of the population of the province and the extent of the variation in population growth, according to the administrative units, has touched search numerical and proportional distribution of the population according to the administrative aspects of the judiciary, as well as environmental distribution.

The elimination of the study population growth dramatically

... Show More
View Publication Preview PDF
Publication Date
Sun Dec 02 2018
Journal Name
Journal Of The College Of Education For Women
The Extent to which Islamic Education Teachers and their Teachers Teach Technological Innovations in Universities
...Show More Authors

The aim of the study is to investigate the extent to which the teachers of Islamic education and their teachers taught the technological innovations in the universities and to test the significance of the differences between the averages of the degree of practice according to the variables: gender, experience, scientific qualification, and educational stage. To achieve these objectives, a questionnaire consisting of (20) (20) teacher and school, teachers of Islamic education in Iraqi universities.

   The results indicated that the degree of the practice of Islamic education teachers and their teachers of technological innovations was moderate, and there were statistically significant differences in the variable of

... Show More
View Publication Preview PDF
Publication Date
Wed Dec 01 2010
Journal Name
Iraqi Journal Of Physics
Amplified Spontaneous Emission of DCM Dye in PMMA Polymer Using Copper Metal Disks Mold
...Show More Authors

The effect of irradiation and exposure time of laser light on the fluorescence emission of DCM dye in PMMA polymer contained in the composition mold using different metals have been investigated. It was found that the fluorescence intensity decreases as the exposure time increases and then reaches stabilization at long times. The effect of the incident laser power on fluorescence intensity of DCM dye in PMMA polymer at 10-3 M and 20% mixing ratio, using copper disks of composition molds, has been studied too. It was observed that there is an upward knick in the curve at laser intensity of 19.2 W/cm2, which may be associated with the threshold for amplified spontaneous emission (ASE) or laser action. And at intensity higher than about 88.

... Show More
View Publication Preview PDF