scholarly journals X-ray spectroscopy evidence for plasma shell formation in experiments modeling accretion columns in young stars

2019 ◽  
Vol 4 (6) ◽  
pp. 064402 ◽  
Author(s):  
E. D. Filippov ◽  
I. Yu. Skobelev ◽  
G. Revet ◽  
S. N. Chen ◽  
B. Khiar ◽  
...  
Keyword(s):  
Young Stars ◽  
Shell Formation ◽  
X Ray ◽  
Plasma Shell

Silicon Substitution for Calcium in the Shell of the Fingernail Clam, Musculium Transversum Studied By X-Ray Analysis

1980 ◽  
Vol 38 ◽  
pp. 560-561
Author(s):  
Judith A. Murphy ◽  
Anthony Paparo ◽  
Richard Sparks
Keyword(s):  
Carbonic Anhydrase ◽  
River Water ◽  
Food Chains ◽  
Well Water ◽  
Shell Formation ◽  
X Ray ◽  
Molluscan Shell ◽  
Fingernail Clams

Fingernail clams (Muscu1ium transversum) are dominant bottom-dwelling animals in some waters of the midwest U.S. These organisms are key links in food chains leading from nutrients in water and mud to fish and ducks which are utilized by man. In the mid-1950’s, fingernail clams disappeared from a 100-mile section of the Illinois R., a tributary of the Mississippi R. Some factor(s) in the river and/or sediment currently prevent clams from recolonizing areas where they were formerly abundant. Recently, clams developed shell deformities and died without reproducing. The greatest mortality and highest incidence of shell deformities appeared in test chambers containing the highest proportion of river water to well water. The molluscan shell consists of CaCO3, and the tissue concerned in its secretion is the mantle. The source of the carbonate is probably from metabolic CO2 and the maintenance of ionized Ca concentration in the mantle is controlled by carbonic anhydrase. The Ca is stored in extracellular concentric spherical granules(0.6-5.5μm) which represent a large amount of inertCa in the mantle. The purpose of this investigation was to examine the role of raw river water and well water on shell formation in the fingernail clam.

Synthesis of mussel-inspired polydopamine-gallium nanoparticles for biomedical applications

Nanomedicine ◽  
2021 ◽  
Author(s):  
Jean Valdir Uchôa Teixeira ◽  
Fátima Raquel Azevedo Maia ◽  
Mariana Carvalho ◽  
Rui Reis ◽  
Joaquim Miguel Oliveira ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Biomedical Applications ◽  
Adipose Derived Stem Cells ◽  
Cell Analysis ◽  
Shell Formation ◽  
X Ray ◽  
Alkali Medium ◽  
Reproducible Method ◽  
Gallium Nanoparticles

Aim: To established a simple, controlled and reproducible method to synthesize gallium (Ga)-coated polydopamine (PDA) nanoparticles (NPs). Materials & methods: PDA NPs were synthesized in alkali medium with posterior Ga shell formation due to ion chelation on the NP surface. Results: The obtained results with energy-dispersive x-ray spectroscopy confirmed the incorporation of Ga on the PDA NP surface. The cytotoxicity of Ga-coated PDA NPs was evaluated in vitro at different concentrations in contact with human adipose-derived stem cells. Further cell analysis also demonstrated the benefit of Ga-coated PDA NPs, which increased the cell proliferation rate compared with noncoated PDA NPs. Conclusion: This study indicated that Ga could work as an appropriate shell for PDA NPs, inducing cell proliferation at the analyzed concentrations.

scholarly journals X‐Ray and Infrared Observations of Embedded Young Stars in NGC 2264

2005 ◽  
Vol 618 (2) ◽  
pp. 795-809 ◽  
Author(s):  
Theodore Simon ◽  
S. E. Dahm
Keyword(s):  
Young Stars ◽  
Infrared Observations ◽  
X Ray

Evaluation of the formation and carbon dioxide capture by Li4SiO4 using in situ synchrotron powder X-ray diffraction studies

2018 ◽  
Vol 20 (41) ◽  
pp. 26570-26579 ◽  
Author(s):  
M. L. Grasso ◽  
M. V. Blanco ◽  
F. Cova ◽  
J. A. González ◽  
P. Arneodo Larochette ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Capture ◽  
Shell Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Formation Pathway ◽  
Capture Capacity

The formation pathway of Li4SiO4 involves Li2SiO3 as an intermediate. Carbonation of Li4SiO4 under dynamical conditions retards the double shell formation, improving CO2 capture capacity.

OPTICAL SPECTROSCOPY OF X-RAY-SELECTED YOUNG STARS IN THE CARINA NEBULA

2015 ◽  
Vol 150 (6) ◽  
pp. 195 ◽  
Author(s):  
Kaushar Vaidya ◽  
Wen-Ping Chen ◽  
Hsu-Tai Lee
Keyword(s):  
Optical Spectroscopy ◽  
Young Stars ◽  
X Ray ◽  
Carina Nebula

scholarly journals Bright X‐Ray Flares in Orion Young Stars from COUP: Evidence for Star‐Disk Magnetic Fields?

2005 ◽  
Vol 160 (2) ◽  
pp. 469-502 ◽  
Author(s):  
F. Favata ◽  
E. Flaccomio ◽  
F. Reale ◽  
G. Micela ◽  
S. Sciortino ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Young Stars ◽  
X Ray

Implications of stellar activity for exoplanetary atmospheres

2010 ◽  
Vol 9 (4) ◽  
pp. 239-243 ◽  
Author(s):  
P. Odert ◽  
M. Leitzinger ◽  
A. Hanslmeier ◽  
H. Lammer ◽  
M.L. Khodachenko ◽  
...  
Keyword(s):  
Extreme Ultraviolet ◽  
Planetary Atmospheres ◽  
Young Star ◽  
Young Stars ◽  
M Dwarfs ◽  
Low Mass Stars ◽  
X Ray ◽  
History Of ◽  
Low Mass ◽  
Exoplanetary Atmospheres

AbstractStellar X-ray and extreme ultraviolet (XUV) radiation is an important driver of the escape of planetary atmospheres. Young stars emit high XUV fluxes that decrease as they age. Since the XUV emission of a young star can be orders of magnitude higher compared to an older one, this evolution has to be taken into account when studying the mass-loss history of a planet. The temporal decrease of activity is closely related to the operating magnetic dynamo, which depends on rotation and convection in Sun-like stars. Using a sample of nearby M dwarfs, we study the relations between age, rotation and activity and discuss the influence on planets orbiting these low-mass stars.

X-Ray Observations of Young Stars Address a Puzzle of the Solar System’s Origin

Physics Today ◽  
2001 ◽  
Vol 54 (11) ◽  
pp. 19-21
Author(s):  
Bertram Schwarzschild
Keyword(s):  
Young Stars ◽  
X Ray

scholarly journals Special Session 7 Young Stars, Brown Dwarfs, and Protoplanetary Disks

2009 ◽  
Vol 5 (H15) ◽  
pp. 727-728
Author(s):  
Jane Gregorio-Hetem ◽  
Silvia Alencar
Keyword(s):  
Adaptive Optics ◽  
Planet Formation ◽  
Protoplanetary Disks ◽  
Brown Dwarfs ◽  
Young Stars ◽  
Special Session ◽  
Brown Dwarf ◽  
X Ray ◽  
Substellar Objects

In recent years our knowledge of star, brown dwarf and planet formation has progressed immensely due to new data in the IR domain (Spitzer telescope), new X-ray campaigns such as the Chandra Orion Ultradeep Project (COUP) and the X-ray Emission Survey of Taurus (XEST), with XMM-Newton, as well as adaptive optics results and synoptic studies of young stellar and substellar objects.

scholarly journals Radio Emission from Extended Shell-Like SNRs

1998 ◽  
Vol 188 ◽  
pp. 249-250
Author(s):  
A.I. Asvarov
Keyword(s):  
Radio Emission ◽  
Thin Shell ◽  
Large Fraction ◽  
Radiative Cooling ◽  
Interstellar Space ◽  
Low Density ◽  
Shell Formation ◽  
X Ray ◽  
Cooling Effects ◽  
X Ray Background

Observations of the soft X-Ray background and interstellar UV absorption lines have indicated that a large fraction of interstellar space is filled with a high temperature low density “coronal” gas. In such low density environments SNRs will expand up to 200 pc in radius without thin shell formation which occurs due to radiative cooling effects. Such SNRs can occupy a large fraction of volume of Galaxy and can be the main source of background emissions. In the present work we examine the evolution of the radio emission of shell-like SNR evolving in the hot ISM.

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