6,116 research outputs found
Corrosion resistant thermal barrier coating
A thermal barrier coating system for protecting metal surfaces at high temperature in normally corrosive environments is described. The thermal barrier coating system includes a metal alloy bond coating, the alloy containing nickel, cobalt, iron, or a combination of these metals. The system further includes a corrosion resistant thermal barrier oxide coating containing at least one alkaline earth silicate. The preferred oxides are calcium silicate, barium silicate, magnesium silicate, or combinations of these silicates
Factors that Influence Fan’s Attendance at Individual Sporting Events in Egypt through Coaches’ and Media Perspective
Egypt has been long reflected as one of the most attractive countries to visit because of its historical treasure. Egypt also has remarkable athletic performances in the world championship and the Olympics. Egypt's first recent Olympic gold medal was during the Athens Olympic Games. However, fans’ attendance at individual sporting events was not equivalent to fan presence at team sports. Related studies about fans' who participate in different sporting events focused on men’s sports, team sports, and professional sports ( Armstrong, 2007). The sports development pyramid model by Casey (1988), designed to analyze the stages of sports development, was used to understand more about the association of the significance ofspecific factorsthat Influence fans’, and fan attendance at different individual sporting events in Egypt. A survey initially designed by the researchers was used to collect insights from seven (7) sports journalists, and twenty-seven (27) national team head coaches from different countries, who attended the African and the Arab games held in Cairo, Egypt. The results showed a significant relationship between fan attendance and individual sporting events, public relations, social media, cultural, and the actions of the Egyptian National Governing Bodies (ENGB). The result of this study further suggests the importance of implementing marketing strategies to promote individual sport
Life Stories of International Romanian Adoptees: A Narrative Study
This study sought to explore the life stories of Romanian adoptees who were internationally adopted following the fall of communism in 1989. Ten participants were recruited via social media and took part in a life stories interview. Data were analysed using narrative analysis, which led to the development of four life chapters centred around identity construction: Chapter 1: Setting the scene – The adoption story; Chapter 2: Constructing the self; Chapter 3: Who am I? Quest for self-discovery; and Chapter 4: Negotiating the selves. Clinical implications, research limitations and suggestions for future research are discussed
Wide awake and ready to move: 20 years of non-viral therapeutic genome engineering with the Sleeping Beauty transposon system
Gene therapies will only become a widespread tool in the clinical treatment of human diseases with the advent of gene transfer vectors that integrate genetic information stably, safely, effectively, and economically. Two decades after the discovery of the Sleeping Beauty (SB) transposon, it has been transformed into a vector system that is fulfilling these requirements. SB may well overcome some of the limitations associated with viral gene transfer vectors and transient non-viral gene delivery approaches that are being used in the majority of ongoing clinical trials. The SB system has achieved a high level of stable gene transfer and sustained transgene expression in multiple primary human somatic cell types, representing crucial steps that may permit its clinical use in the near future. This article reviews the most important aspects of SB as a tool for gene therapy, including aspects of its vectorization and genomic integration. As an illustration, the clinical development of the SB system toward gene therapy of age-related macular degeneration and cancer immunotherapy is highlighted
WFPC2 Observations of Massive and Compact Young Star Clusters in M31
We present color magnitude diagrams of four blue massive and compact star
clusters in M31: G38, G44, G94, and G293. The diagrams of the four clusters
reveal a well-populated upper main sequence and various numbers of supergiants.
The U-B and B-V colors of the upper main sequence stars are used to determine
reddening estimates of the different lines of sight in the M31 disk. Reddening
values range from E(B-V) = 0.20 +/- 0.10 to 0.31 +/- 0.11. We statistically
remove field stars on the basis of completeness, magnitude and color. Isochrone
fits to the field-subtracted, reddening-corrected diagrams yield age estimates
ranging from 63 +/- 15 Myr to 160 +/- 60 Myr. Implications for the recent
evolution of the disk near NGC 206 are discussed.Comment: 17 pages, Latex, ApJ, in Pres
The Glass Transition Temperature of Water: A Simulation Study
We report a computer simulation study of the glass transition for water. To
mimic the difference between standard and hyperquenched glass, we generate
glassy configurations with different cooling rates and calculate the
dependence of the specific heat on heating. The absence of crystallization
phenomena allows us, for properly annealed samples, to detect in the specific
heat the simultaneous presence of a weak pre-peak (``shadow transition''), and
an intense glass transition peak at higher temperature.
We discuss the implications for the currently debated value of the glass
transition temperature of water. We also compare our simulation results with
the Tool-Narayanaswamy-Moynihan phenomenological model.Comment: submitted to Phys. Re
On the stellar populations in NGC 185 and NGC 205, and the nuclear star cluster in NGC 205 from Hubble Space Telescope observations
[Abridged] We present a first detailed analysis of resolved stellar
populations in the dwarf galaxies NGC 185 and NGC 205 based on archival V- and
I-band WFPC2 pointings. For NGC 185 we deduce that star formation was probably
still active about 4 x 10^8 yr ago. Key abundance-related results are: (1) We
identify ancient stars with [Fe/H] <~ -1.5 dex by a well-defined horizontal
branch (HB). (2) We find a prominent RGB/ faint-AGB clump/ bump- like feature
with the same mean V-band magnitude as the HB, within uncertainties; from a
comparison with theory, ancient stars have [Fe/H] ~ -1.5 dex, with a higher
abundance level for intermediate-age stars. (3) From colour information we
infer that the median [Fe/H] > -1.11 +/- 0.08 dex for ancient stars. For NGC
205, we record (m-M)o = 24.76 +/- 0.1 mag, based on the RGB I-band tip
magnitude method. We find that stars were probably still forming less than 3 x
10^8 yr ago, which is compatible with star formation triggered by an
interaction with M31. Key abundance-related results are: (1) The RGB/ faint-AGB
is significantly skewed to redder values than that of a control field in the
outskirts of M31; it probably results from a relatively narrow metallicity and
or age range for a significant fraction of the dwarf's stars. (2) For ancient
stars we infer from colour information that the median [Fe/H] > -1.06+/-0.04
dex. We briefly compare the stellar populations of NGC 205, NGC 185 and NGC
147.
Finally, we find an apparent blue excess in the outer region of the nuclear
star cluster in NGC 205. It is as compact as a typical galactic globular
cluster, but is quite bright (10^6 L_solar,R); and by matching its blue colour
with models, its stellar population is young, up to a few times 10^8 yr old.Comment: To appear in the May edition of the Astronomical Journal. Some
figures have been degraded in quality for the purpose of submissio
First Results from Fermi GBM Earth Occultation Monitoring: Observations of Soft Gamma-Ray Sources Above 100 keV
The NaI and BGO detectors on the Gamma-ray Burst Monitor (GBM) on Fermi are
now being used for long-term monitoring of the hard X-ray/low energy gamma-ray
sky. Using the Earth occultation technique as demonstrated previously by the
BATSE instrument on the Compton Gamma-Ray Observatory, GBM can be used to
produce multiband light curves and spectra for known sources and transient
outbursts in the 8 keV to 1 MeV energy range with its NaI detectors and up to
40 MeV with its BGO detectors. Over 85% of the sky is viewed every orbit, and
the precession of the Fermi orbit allows the entire sky to be viewed every ~26
days with sensitivity exceeding that of BATSE at energies below ~25 keV and
above ~1.5 MeV. We briefly describe the technique and present preliminary
results using the NaI detectors after the first two years of observations at
energies above 100 keV. Eight sources are detected with a significance greater
than 7 sigma: the Crab, Cyg X-1, SWIFT J1753.5-0127, 1E 1740-29, Cen A, GRS
1915+105, and the transient sources XTE J1752-223 and GX 339-4. Two of the
sources, the Crab and Cyg X-1, have also been detected above 300 keV.Comment: 13 pages, 9 figures, submitted to Ap
The star formation history of the Local Group dwarf elliptical galaxy NGC 185: II. Gradients in the stellar population
The star formation history of the dE NGC 185, together with its spatial
variations, has been investigated using new ground-based and
photometry, and synthetic color--magnitude diagrams (CMDs). We find that the
bulk of the stars were formed in NGC 185 at an early epoch of its evolution.
After that, the star formation proceeded at a low rate until the recent past,
the age of the most recent traces of star formation activity detected in the
galaxy being some 100 Myr.
The star formation rate, for old and intermediate ages shows a
gradient in the sense of taking smaller values for higher galactocentric radii.
Moreover, recent star formation is detected in the central
pc only, where the youngest, 100 Myr old population is
found. The luminous blue {\it stars} discovered by Baade (1951) in the center
of NGC 185 are discussed using new CCD images in and Baade's original
photographic plates, reaching the conclusion that most of them are in fact star
clusters. A consistent picture arises in which the gas observed in the central
region of NGC 185 would have an internal origin. The rate at which evolved
stars return gas to the ISM is enough to seed the recent star formation
observed in the center of the galaxy and the SN rate is probably low enough to
allow the galaxy to retain the gas not used in the new stellar generations.Comment: 34 pages, 17 figures, 5 Tables, to be published in AJ October 9
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