scholarly journals A comparative study of the method of Williamson Hall and the pattern of cadmium oxide nanoparticles for X-rays

2021 ◽  
Vol 12 (4) ◽  
pp. 881-889
Author(s):  
Esraa Ahmed Mohammed
Keyword(s):  
Texture Coefficient ◽  
Cadmium Oxide ◽  
Physical Parameters ◽  
X Rays ◽  
Nano Structure ◽  
Crystalline Materials ◽  
X Ray ◽  
Cdo Nanoparticles ◽  
Special Area ◽  
Diffraction Effects

X-ray difraction (XRD) is an effective non-destructive instrument used in the determination and analysis of amorphous and crystalline materials. Three basic elements are the X-ray diffractometers: the X-ray tube, a retention of samples and an X-ray detector. In many industries such as diodes, transistors, detectors, solar and photovoltaic cells, cadmium oxide CdO nanoparticles are used. For this analysis, CdO nanoparticles are semi-conductors (type) and band-gaps of 2.5 eV and 1.98 eV in direct and indirect bands using cadmium oxide. Several temperatures, effects and parameters such as texture coefficient (TC), dislocation density(μ), special area (SSA), and micro strain were measured and determined (S). The peaks of the analysis were the extension of the nano structure, crystal size and grid pressure of the CdO and were measured using the Size Train Plot of Williamson-Hall (SSP). The composition of the particle is the cubic fluorite and spatial group Fm-3m (225). In the peaks resulting from the calcination process, strain enlargement was observed. Accordingly, the above procedure determined all physical parameters as a result of the diffraction effects.

scholarly journals Multiwavelength Modeling the SED of Strongly Interacting Binaries

2011 ◽  
Vol 7 (S282) ◽  
pp. 65-66
Author(s):  
Augustin Skopal
Keyword(s):  
Physical Parameters ◽  
X Rays ◽  
Physical Processes ◽  
Short Contribution ◽  
Composite Spectrum ◽  
X Ray ◽  
Strongly Interacting ◽  
Low Mass ◽  
X Ray Binaries

AbstractThe spectrum of strongly interacting binaries, as for example, high and low mass X-ray binaries, symbiotic (X-ray) binaries and/or classical and recurrent novae, consists of more components of radiation contributing from hard X-rays to radio wavelengths. To understand the basic physical processes responsible for the observed spectrum we have to disentangle the composite spectrum into its individual components, i.e. to determine their physical parameters. In this short contribution I demonstrate the method of modeling the multiwavelength SED on the example of the extragalactic super-soft X-ray source RX J0059.1-7505 (LIN 358).

Applications of High-Resolution Powder X-Ray Diffraction

2007 ◽  
Vol 130 ◽  
pp. 7-14 ◽  
Author(s):  
Andrew N. Fitch
Keyword(s):  
High Resolution ◽  
Synchrotron Radiation ◽  
Powder Diffraction ◽  
X Rays ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Structural Characterisation ◽  
Pdf Analysis

The highly-collimated, intense X-rays produced by a synchrotron radiation source can be harnessed to build high-resolution powder diffraction instruments with a wide variety of applications. The general advantages of using synchrotron radiation for powder diffraction are discussed and illustrated with reference to the structural characterisation of crystalline materials, atomic PDF analysis, in-situ and high-throughput studies where the structure is evolving between successive scans, and the measurement of residual strain in engineering components.

scholarly journals The X-ray/UV ratio in active galactic nuclei: dispersion and variability

2018 ◽  
Vol 619 ◽  
pp. A95 ◽  
Author(s):  
E. Chiaraluce ◽  
F. Vagnetti ◽  
F. Tombesi ◽  
M. Paolillo
Keyword(s):  
Black Hole ◽  
Cosmological Parameters ◽  
Multivariate Regression Analysis ◽  
Physical Parameters ◽  
Distance Modulus ◽  
X Rays ◽  
Viewing Angle ◽  
Black Hole Mass ◽  
Intrinsic Variability ◽  
X Ray

Context. The well established negative correlation between the αOX spectral slope and the optical/ultraviolet (UV) luminosity, a by-product of the relation between X-rays and optical/UV luminosity, is affected by relatively large dispersion. The main contributors to this dispersion can be variability in the X-ray/UV ratio and/or changes in fundamental physical parameters. Aims. We want to quantify the contribution from variability within single sources (intra-source dispersion) and that from variations of other quantities different from source to source (inter-source dispersion). Methods. We use archival data from the XMM-Newton Serendipitous Source Catalog (XMMSSC) and from the XMM-OM Serendipitous Ultraviolet Source Survey (XMMOM-SUSS3). We select a sub-sample in order to decrease the dispersion of the relation due to the presence of radio-loud and broad absorption line objects, and that due to absorptions in both X-ray and optical/UV bands. We use the structure function (SF) to estimate the contribution from variability to the dispersion. We analyse the dependence of the residuals of the relation on various physical parameters in order to characterise the inter-source dispersion. Results. We find a total dispersion of σ ∼ 0.12 and find that intrinsic variability contributes 56% of the variance of the αOX − LUV relation. If we select only sources with a larger number of observational epochs (≥3) the dispersion of the relation decreases by approximately 15%. We find weak but significant dependencies of the residuals of the relation on black-hole mass and on Eddington ratio, which are also confirmed by a multivariate regression analysis of αOX as a function of UV luminosity and black-hole mass and/or Eddington ratio. We find a weak positive correlation of both the αOX index and the residuals of the αOX − LUV relation with inclination indicators, such as the full width at half maximum (Hβ) and the equivalent width (EW)[OIII], suggesting a weak increase of X-ray/UV ratio with the viewing angle. This suggests the development of new viewing angle indicators possibly applicable at higher redshifts. Moreover, our results suggest the possibility of selecting a sample of objects, based on their viewing angle and/or black-hole mass and Eddington ratio, for which the αOX − LUV relation is as tight as possible, in light of the use of the optical/UV – X-ray luminosity relation to build a distance modulus (DM)-z plane and estimate cosmological parameters.

scholarly journals 1/4 Ke V Diffuse Background and the Local Interstellar Medium

1989 ◽  
Vol 120 ◽  
pp. 536-536
Author(s):  
S.L. Snowden
Keyword(s):  
Interstellar Medium ◽  
Filling Factor ◽  
Thermal Emission ◽  
Mean Free Path ◽  
Physical Parameters ◽  
X Rays ◽  
Local Interstellar Medium ◽  
X Ray ◽  
Diffuse Background ◽  
X Ray Background

The 1/4 keV diffuse X-ray background (SXRB) is discussed in relation to the local interstellar medium (LISM). The most likely source for these soft X-rays is thermal emission from a hot diffuse plasma. The existence of a non-zero flux from all directions and the short ISM mean free path of these X-rays (1020HI cm-2), coupled with ISM pressure constraints, imply that the plasma has a local component and that it must, at least locally (nearest hundred parsecs), have a large filling factor. Our understanding of the geometry and physical parameters of the LISM is therefore directly tied to our understanding of the SXRB.

scholarly journals Radio and X-ray connection in radio mini-halos: Implications for hadronic models

2020 ◽  
Vol 640 ◽  
pp. A37 ◽  
Author(s):  
A. Ignesti ◽  
G. Brunetti ◽  
M. Gitti ◽  
S. Giacintucci
Keyword(s):  
Magnetic Field ◽  
Large Fraction ◽  
Cosmic Ray ◽  
Physical Parameters ◽  
Model Parameters ◽  
Relativistic Electrons ◽  
X Rays ◽  
X Ray ◽  
Hadronic Model ◽  
Radio Halos

Context. A large fraction of cool-core clusters are known to host diffuse, steep-spectrum radio sources, called radio mini-halos, in their cores. Mini-halos reveal the presence of relativistic particles on scales of hundreds of kiloparsecs, beyond the scales directly influenced by the central active galactic nucleus (AGN), but the nature of the mechanism that produces such a population of radio-emitting, relativistic electrons is still debated. It is also unclear to what extent the AGN plays a role in the formation of mini-halos by providing the seeds of the relativistic population. Aims. In this work we explore the connection between thermal and non-thermal components of the intra-cluster medium in a sample of radio mini-halos and we study the implications within the framework of a hadronic model for the origin of the emitting electrons. Methods. For the first time, we studied the thermal and non-thermal connection by carrying out a point-to-point comparison of the radio and the X-ray surface brightness in a sample of radio mini-halos. We extended the method generally applied to giant radio halos by considering the effects of a grid randomly generated through a Monte Carlo chain. Then we used the radio and X-ray correlation to constrain the physical parameters of a hadronic model and we compared the model predictions with current observations. Results. Contrary to what is generally reported in the literature for giant radio halos, we find that the mini-halos in our sample have super-linear scaling between radio and X-rays, which suggests a peaked distribution of relativistic electrons and magnetic field. We explore the consequences of our findings on models of mini-halos. We use the four mini-halos in the sample that have a roundish brightness distribution to constrain model parameters in the case of a hadronic origin of the mini-halos. Specifically, we focus on a model where cosmic rays are injected by the central AGN and they generate secondaries in the intra-cluster medium, and we assume that the role of turbulent re-acceleration is negligible. This simple model allows us to constrain the AGN cosmic ray luminosity in the range ∼1044−46 erg s−1 and the central magnetic field in the range 10–40 μG. The resulting γ-ray fluxes calculated assuming these model parameters do not violate the upper limits on γ-ray diffuse emission set by the Fermi-LAT telescope. Further studies are now required to explore the consistency of these large magnetic fields with Faraday rotation studies and to study the interplay between the secondary electrons and the intra-cluster medium turbulence.

scholarly journals Preparation and Study of Colloidal CdO Nanoparticles by Laser Ablation in Polyvinylpyrrolidone

2016 ◽  
Vol 6 ◽  
pp. 1-7 ◽  
Author(s):  
Ibrahim R. Agool ◽  
Ahmed N. Abd ◽  
Mohammed O. Dawood
Keyword(s):  
Optical Properties ◽  
Laser Ablation ◽  
Pulse Energy ◽  
Cadmium Oxide ◽  
Colloidal Nanoparticles ◽  
Solid Target ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Force ◽  
Cdo Nanoparticles

Nanoparticles NPSof cadmium oxide CdO were generated by laser ablation of a solid target (cadmium) in polyvinylpyrrolidone (PVP) solution. CdO colloidal nanoparticles have been synthesized by laser ablation Nd:YAG (1064 nm, 100 pulses, pulse energy= 400 mJ) when the solid target CdO was immersed in PVP. Structure, topography and optical properties of the CdO nanoparticles NPShave been studied using X-ray diffraction (XRD), atomic force microscope (AFM) and the UV-Vis absorption respectively.

Diffraction

2002 ◽  
Author(s):  
David Blow
Keyword(s):  
Red Light ◽  
Three Dimensional ◽  
Three Dimensions ◽  
X Rays ◽  
X Ray ◽  
Original Direction ◽  
Computational Procedures ◽  
Scattering Material ◽  
Opaque Object ◽  
Diffraction Effects

Diffraction refers to the effects observed when light is scattered into directions other than the original direction of the light, without change of wavelength. An X-ray photon may interact with an electron and set the electron oscillating with the X-ray frequency. The oscillating electron may radiate an X-ray photon of the same wavelength, in a random direction, when it returns to its unexcited state. Other processes may also occur, akin to fluorescence, which emit X-rays of longer wavelengths, but these processes do not give diffraction effects. Just as we see a red card because red light is scattered off the card into our eyes, objects are observed with X-rays because an illuminating X-ray beam is scattered into the X-ray detector. Our eye can analyse details of the card because its lens forms an image on the retina. Since no X-ray lens is available, the scattered X-ray beam cannot be converted directly into an image. Indirect computational procedures have to be used instead. X-rays are penetrating radiation, and can be scattered from electrons throughout the whole scattering object, while light only shows the external shape of an opaque object like a red card. This allows X-rays to provide a truly three-dimensional image. When X-rays pass near an atom, only a tiny fraction of them is scattered: most of the X-rays pass further into the object, and usually most of them come straight out the other side of the whole object. In forming an image, these ‘straight through’ X-rays tell us nothing about the structure, and they are usually captured by a beam stop and ignored. This chapter begins by explaining that the diffraction of light or X-rays can provide a precise physical realization of Fourier’s method of analysing a regularly repeating function. This method may be used to study regularly repeating distributions of scattering material. Beginning in one dimension, examples will be used to bring out some fundamental features of diffraction analysis. Graphic examples of two-dimensional diffraction provide further demonstrations. Although the analysis in three dimensions depends on exactly the same principles, diffraction by a three-dimensional crystal raises additional complications.

The Use of 2-D Detector Utilizing Laser-Stimulated Luminescence for X-ray Diffraction Studies on Mechanical Behaviour of Materials

1989 ◽  
Vol 33 ◽  
pp. 389-396 ◽  
Author(s):  
Y. Yoshioka ◽  
T. Shinkai ◽  
S. Ohya
Keyword(s):  
Fracture Analysis ◽  
X Rays ◽  
Large Reduction ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Material Evaluation ◽  
Position Sensitive ◽  
Diffraction Patterns ◽  
Position Sensitive Detectors

The development of linear position-sensitive detectors (PSD) has resulted in a large reduction of data acquisition times in the field of x-ray stress analysis. However, we also require two-dimensional (2-D) diffraction patterns for material evaluation. Especially, the microbeam x-ray diffraction technique gives valuable information on the structure of crystalline materials and this technique has been applied to fracture analysis by x-rays. Many kinds of 2-D PSD have been developed that have insufficient spatial resolution. So x-ray film has still been used as a 2-D detector, but it requires relatively long exposure times and then the process after exposure is very troublesome.

Synthesis, Characterization, and Photovoltaic Performance of CdO-Based Nano Hybrid Material in Solid-State Dye-Sensitized Solar Cells

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Arifa Batool ◽  
Syed Mujtaba Shah ◽  
Naimat Ullah ◽  
Hazrat Hussain
Keyword(s):  
Sol Gel ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Cadmium Oxide ◽  
Visible Region ◽  
Solar Spectrum ◽  
Energy Dispersive ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Cdo Nanoparticles

Abstract Cadmium oxide nanoparticles (NPs) were successfully synthesized through the simple and low-cost sol–gel method. The optical, morphological, compositional, and structural properties of as-synthesized NPs were investigated by ultraviolet–visible (UV/Vis) spectroscopy, fluorescence spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) analysis. Absorption spectra of CdO NPs were used for band gaps calculation, which was found to be 2.11 eV. The XRD pattern was used to investigate the purity and crystalline nature of NPs. Morphology and elemental composition were investigated by using SEM and energy-dispersive X-ray spectroscopy (EDX), respectively. FTIR assisted in identifying the functional groups and grafting of the dye on the surface of NPs. These CdO nanoparticles were photosensitized with Ru (II) based Z907 dye. Z907 dye was employed to extend the absorption spectrum of the material to the visible region of the solar spectrum so as to harvest the maximum amount of solar influx on the surface of earth. The energy level diagram revealed that the interaction among the constituents of the nanohybrid assembly permitted the flow of the electron in a cascade manner from dye to CdO nanoparticles. The synthesized photoactive nanohybrid material was thoroughly blended with poly (3-hexylthiophene), a solid electrolyte, and I–V measurements under simulated radiations 1000 W/m2 (AM 1.5) were recorded. A maximum induced photon to the current conversion efficiency of 0.60% was achieved.

scholarly journals Structure of X-ray emitting jets close to the launching site: from embedded to disk-bearing sources

2018 ◽  
Vol 615 ◽  
pp. A124 ◽  
Author(s):  
S. Ustamujic ◽  
S. Orlando ◽  
R. Bonito ◽  
M. Miceli ◽  
A. I. Gómez de Castro
Keyword(s):  
Ambient Medium ◽  
Class Ii ◽  
Young Stellar Objects ◽  
Physical Parameters ◽  
X Rays ◽  
X Ray ◽  
Stationary Shock ◽  
T Tauri ◽  
Stellar Jets ◽  
Launching Site

Context. Several observations of stellar jets show evidence of X-ray emitting shocks close to the launching site. In some cases, including young stellar objects (YSOs) at different stages of evolution, the shocked features appear to be stationary. We study two cases, both located in the Taurus star-forming region. HH 154, the jet originating from the embedded binary Class 0/I protostar IRS 5, and the jet associated with DG Tau, a more evolved Class II disk-bearing source or classical T Tauri star (CTTS). Aims. We investigate the effect of perturbations in X-ray emitting stationary shocks in stellar jets and the stability and detectability in X-rays of these shocks, and we explore the differences in jets from Class 0 to Class II sources. Methods. We performed a set of 2.5D magnetohydrodynamic numerical simulations that model supersonic jets ramming into a magnetized medium. The jet is formed of two components: a continuously driven component that forms a quasi-stationary shock at the base of the jet and a pulsed component consisting of blobs perturbing the shock. We explored different parameters for the two components. We studied two cases: HH 154, a light jet (less dense than the ambient medium), and a heavy jet (denser than the ambient medium) associated with DG Tau. We synthesized the count rate from the simulations and compared these data with available Chandra observations. Results. Our model is able to reproduce the observed jet properties at different evolutionary phases (in particular, for HH 154 and DG Tau) and can explain the formation of X-ray emitting quasi-stationary shocks observed at the base of jets in a natural way. The jet is collimated by the magnetic field forming a quasi-stationary shock at the base which emits in X-rays even when perturbations formed by a train of blobs are present. We found similar collimation mechanisms dominating in both heavy and light jets. Conclusions. We derived the physical parameters that can give rise to X-ray emission consistent with observations of HH 154 and DG Tau. We have also performed a wide exploration of the parameter space characterizing the model; this can be a useful tool to study and diagnose the physical properties of YSO jets over a broad range of physical conditions, from embedded to disk-bearing sources. We show that luminosity does not change significantly in variable jet models for the range of parameters explored. Finally, we provide an estimation of the maximum perturbations that can be present in HH 154 and DG Tau taking into account the available X-ray observations.

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