scholarly journals The prospects for constraining dark energy with future X-ray cluster gas mass fraction measurements

2008 ◽  
Vol 388 (3) ◽  
pp. 1265-1278 ◽  
Author(s):  
David Rapetti ◽  
Steven W. Allen ◽  
Adam Mantz
Keyword(s):  
Dark Energy ◽  
Mass Fraction ◽  
X Ray

Preparation of β-PbO2 and β-PbO2-MnO2 Coating on Stainless Steel Substrate

2012 ◽  
Vol 490-495 ◽  
pp. 3486-3490
Author(s):  
Qiang Yu ◽  
Zhen Chen ◽  
Zhong Cheng Guo
Keyword(s):  
Stainless Steel ◽  
Mass Fraction ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
Substrate Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Type ◽  
Plating Solution ◽  
Element Mass Fraction

In order to prepare a new type of anode material, stainless steel was selected as substrate material. The β-PbO2 coating on stainless steel substrate was prepared under the appropriate plating solution, and the PbO2-MnO2 coating was prepared with thermal decomposition. The crystal structure was determined by X-ray diffraction; Surface morphology was test by Scanning Electron Microscopy; the energy spectrum was used to determine element mass-fraction and the ratio of atomic number of the coatings.

scholarly journals FORMATION OF DARK MATTER HALOES IN A HOMOGENEOUS DARK ENERGY UNIVERSE

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1397-1403
Author(s):  
L. MARASSI
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Large Scale ◽  
State Parameter ◽  
Mass Function ◽  
Accelerated Expansion ◽  
X Ray ◽  
Energy Models ◽  
Dark Energy Component ◽  
Standard Press

Several independent cosmological tests have shown evidences that the energy density of the universe is dominated by a dark energy component, which causes the present accelerated expansion. The large scale structure formation can be used to probe dark energy models, and the mass function of dark matter haloes is one of the best statistical tools to perform this study. We present here a statistical analysis of mass functions of galaxies under a homogeneous dark energy model, proposed in the work of Percival (2005), using an observational flux-limited X-ray cluster survey, and CMB data from WMAP. We compare, in our analysis, the standard Press–Schechter (PS) approach (where a Gaussian distribution is used to describe the primordial density fluctuation field of the mass function), and the PL (power–law) mass function (where we apply a non-extensive q-statistical distribution to the primordial density field). We conclude that the PS mass function cannot explain at the same time the X-ray and the CMB data (even at 99% confidence level), and the PS best fit dark energy equation of state parameter is ω = -0.58, which is distant from the cosmological constant case. The PL mass function provides better fits to the HIFLUGCS X-ray galaxy data and the CMB data; we also note that the ω parameter is very sensible to modifications in the PL free parameter, q, suggesting that the PL mass function could be a powerful tool to constrain dark energy models.

Effect of technological parameters of gas-dynamic deposition on structural-phase transformations in “brass” type coating

2020 ◽  
pp. 554-559
Author(s):  
V.E. Arkhipov ◽  
T.I. Murav’eva ◽  
M.S. Pugachev ◽  
I.V. Shkaley
Keyword(s):  
Deposition Temperature ◽  
Mass Fraction ◽  
Structural Phase ◽  
X Ray Diffraction ◽  
Technological Parameters ◽  
X Ray ◽  
Type Compound ◽  
Gas Dynamic ◽  
Ε Phase ◽  
Overlap Coefficient

The results of effect of deposition temperature and the overlap coefficient on the formation of the phase composition of coating based on Cu, Zn and Al2O3 particles mixture applied by cold gas-dynamic deposition are presented. Using X-ray diffraction and X-ray spectral analysis, it is shown that when using the 55 % overlap coefficient electron-type compound based on CuZn3 (ε-phase) is formed in the coating, the mass fraction of which increases to 11.4 % with increase in the deposition temperature. Deposition with 64 % overlap coefficient is accompanied by the formation not only of the ε-phase, but of electron-type compound based on Cu5Zn8 (γ-phase), the mass fraction of which increases to 33 % at temperature of 450 °C. In the process of coating deposition, the predominant diffusion copper into zinc takes place; the calculations show high value of the diffusion coefficient copper — 1,56•10–13 m2 /s.

scholarly journals Constraining the dark energy with galaxy cluster x-ray data

2003 ◽  
Vol 68 (2) ◽  
Author(s):  
J. A. S. Lima ◽  
J. V. Cunha ◽  
J. S. Alcaniz
Keyword(s):  
Dark Energy ◽  
Galaxy Cluster ◽  
X Ray

scholarly journals The Effect of Immersion Time of Coconut Fiber in Limestone Water on Tensile Strength and Surface Morphology

2020 ◽  
Vol 55 (3) ◽  
Author(s):  
Sutrisno ◽  
Rudy Soenoko ◽  
Yudy Surya Irawan ◽  
Teguh Dwi Widodo
Keyword(s):  
Tensile Strength ◽  
Surface Morphology ◽  
Mass Fraction ◽  
Immersion Time ◽  
Testing Machine ◽  
Coconut Fiber ◽  
Tensile Testing Machine ◽  
X Ray ◽  
Coir Fibers ◽  
Infrared Spectrometer

This study aims to identify the effect of immersion of coconut fiber in limestone water on surface morphology and tensile strength, including chemical reactions during immersion. Coconut coir fibers were immersed in a solution of limestone water for 0, 4, 8, 12, 16, and 20 hours, with a mass fraction of limestone of 5%, then dried for 1 hour. Coconut fiber was characterized by a single fiber tensile testing machine, Scanning Electron Microscope, X-ray diffractometer, and Fourier transform infrared spectrometer. The results showed that the percentage of 5% with 8 hours of immersion in the fiber had a cleaner surface morphology with a tensile strength of 234.62 MPa. Therefore, as an alternative to improving the characteristics of a single thread, immersion in limestone water needs to be applied.

scholarly journals Morphological, chemical and optical absorbing characterization of aerosols in the urban atmosphere of Valladolid

2005 ◽  
Vol 5 (10) ◽  
pp. 2739-2748 ◽  
Author(s):  
S. Mogo ◽  
V. E. Cachorro ◽  
A. M. de Frutos
Keyword(s):  
Mass Fraction ◽  
Fine Particles ◽  
Aerosol Particles ◽  
Cascade Impactor ◽  
Urban Atmosphere ◽  
Coarse Particles ◽  
X Ray ◽  
Illumination System ◽  
Inverse Power Law

Abstract. Samples of atmospheric aerosol particles were collected in Valladolid, Spain, during the winter of 2003-2004. The measurements were made with a Dekati PM10 cascade impactor with four size stages: greater than 10 µm, between 2.5 to 10 µm, 1 to 2.5 µm and less than 1 µm. The size and shape of the particles were analyzed with a scanning electron microscope (SEM) and elemental analysis was done with an energy dispersive x-ray analysis (EDX). We present an evaluation by size, shape and composition of the major particulate species in the Valladolid urban atmosphere. The total aerosol concentration is very variable, ranging from 39.86 µg·m-3 to 184.88 µg·m-3 with the coarse particles as the dominant mass fraction. Emphasis was given to fine particles (<1 µm), for which the visible (400 nm to 650 nm) light absorption coefficients were measured using the integrating plate technique. We have made some enhancements in the illumination system of this measurement system. The absorption coefficient, σa, is highly variable and ranges from 7.33×10-6 m-1 to 1.01×10-4 m-1 at a wavelength of 550 nm. There is an inverse power law relationship between σa and wavelength, with an average exponent of -0.8.

scholarly journals X-ray Cluster Large Scale Structure and Cosmology

2005 ◽  
Vol 216 ◽  
pp. 373-380
Author(s):  
Marguerite Pierre
Keyword(s):  
Dark Energy ◽  
Galaxy Clusters ◽  
Large Scale ◽  
Scaling Law ◽  
Large Scale Structure ◽  
Short Review ◽  
Scale Structure ◽  
X Ray ◽  
Recent Advances

We outline the main arguments in favor of cosmological X-ray surveys of galaxy clusters. We summarize recent advances in our understanding of cluster physics. After a short review of past surveys, we present the scientific motivations of the XMM Large Scale Structure survey. We further illustrate how such a survey can help constrain the nature of the dark energy as well as cluster scaling law evolution, i.e. non-gravitational physics.

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