Results 51 to 60 of about 105,508 (303)

The thickness of galaxy disks from z=5 to 0 probed by JWST [PDF]

arXiv, 2023
Although thick disk is a structure prevalent in local disk galaxies and also present in our home Galaxy, its formation and evolution is still unclear. Whether the thick disk is born thick and/or gradually heated to be thick after formation is under debate.
arxiv  

Observation of Disk Scattering Slab Modes Transitioning to Disk Scattering Modes on Metal–Dielectric Heterostructures in the Terahertz Waveband

IEEE Photonics Journal, 2015
It has been demonstrated that, in the terahertz (THz) waveband, disk scattering slab modes (DSSMs) can exist in a heterostructure composed of a metallic subwavelength disk array coated on one surface of a dielectric slab.
Wei Wang, Jinsong Liu, Kejia Wang, Zhengang Yang, Kefei Ye   +4 more
doaj   +1 more source

Subsystems of the Galactic halo, their structures and compositions

Odessa Astronomical Publications, 2017
It is shown that general populations of globular clusters and metal-poor field stars are components at least of three subsystems occupying different volumes in the Galaxy.
V. A. Marsakov, T. V. Borkova
doaj   +1 more source

Evaluating the use of diagnostic CT with flattening filter free beams for palliative radiotherapy: Dosimetric impact of scanner calibration variability

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract Purpose Palliative radiotherapy comprises a significant portion of the radiation treatment workload. Volumetric‐modulated arc therapy (VMAT) improves dose conformity and, in conjunction with flattening filter free (FFF) delivery, can decrease treatment times, both of which are desirable in a population with a high probability of retreatment ...
Madeleine L. Van de Kleut, Lesley A. Buckley, Elsayed S. M. Ali   +2 more
wiley   +1 more source

Graphene overcoats for ultra-high storage density magnetic media

Nature Communications, 2021
The main limitation to the areal storage density of hard disk drives (HDDs) is the thickness of carbon overcoats protecting the disk media. Here,
N. Dwivedi, A. K. Ott, K. Sasikumar, C. Dou, R. J. Yeo, B. Narayanan, U. Sassi, D. De Fazio, G. Soavi, T. Dutta, O. Balci, S. Shinde, J. Zhang, A. K. Katiyar, P. S. Keatley, A. K. Srivastava, S. K. R. S. Sankaranarayanan, A. C. Ferrari, C. S. Bhatia   +18 more
doaj   +1 more source

Beryllium and the formation of the Thick Disk and of the Halo [PDF]

Proceedings of the International Astronomical Union, 2008
AbstractWe use Beryllium to investigate star formation in the early Galaxy. Be has been demonstrated to be a good indicator of time in these early epochs. By analyzing the so-far largest sample of halo and thick disk metal poor stars, we find a clear scatter in Be for a given value of [Fe/H] and [O/H].
Pasquini, Luca, Smiljanic, Rodolfo, Bonifacio, Piercarlo, Gratton, R. G., Galli, Daniele, Randich, Sofia   +5 more
openaire   +4 more sources

Fast, automated optimization of virtual monoenergetic images with the dual‐energy image synthesizer for cone‐beam CT

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract Background Dual‐energy cone‐beam CT (DE‐CBCT) has become subject of recent interest due to the ability to produce virtual monoenergetic images (VMIs) with improved soft‐tissue contrast and reduced nonuniformity artifacts. However, efficient production and optimization of VMIs remains an under‐explored part of DE‐CBCT's application.
Andrew Keeler, Jason Luce, Mathias Lehmann, John C. Roeske, Hyejoo Kang   +4 more
wiley   +1 more source

THE MILKY WAY HAS NO DISTINCT THICK DISK [PDF]

The Astrophysical Journal, 2012
Different stellar sub-populations of the Milky Way's stellar disk are known to have different vertical scale heights, their thickness increasing with age. Using SEGUE spectroscopic survey data, we have recently shown that mono-abundance sub-populations, defined in the [ /Fe]-[Fe/H] space, are well described by single exponential spatial-density ...
Jo Bovy, Hans-Walter Rix, David W. Hogg, David W. Hogg   +3 more
openaire   +3 more sources

Surface dose analysis and dosimetric comparison of Halcyon versus Truebeam in breast cancer radiotherapy: An OSL dosimetry study

Journal of Applied Clinical Medical Physics, EarlyView.
Abstract Purpose Breast cancer is a neoplastic disease with high prevalence among women. Radiotherapy is one of the principal treatment modalities for this disease, but it poses significant challenges. This study aimed to compare and evaluate the technical and dosimetric performance of conventional C‐arm linac systems and a new design, Halcyon, in the ...
Mustafa Çağlar, Kudret Akçay, Esra Serin, Dursun Eşitmez, Mehmet Sıddık Cebe, Navid Kheradmand, Ömer Yazıcı, Dilek Ünal, Evrim Metcalfe   +8 more
wiley   +1 more source

The Thickness of Galaxy Disks from z = 5 to 0 Probed by JWST

The Astrophysical Journal Letters
Although a thick disk is a structure prevalent in local disk galaxies and also present in our home Galaxy, its formation and evolution are still unclear.
Jianhui Lian, Li Luo
doaj   +1 more source