scholarly journals Extraction Chromatography Materials Prepared with HDEHP on Different Inorganic Supports for the Separation of Gadolinium and Terbium

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1390
Author(s):  
Fabiola Monroy-Guzman ◽  
Celia del Carmen De la Cruz Barba ◽  
Edgar Jaime Salinas ◽  
Vicente Garibay-Feblés ◽  
Tobias Noel Nava Entzana
Keyword(s):  
Extraction Chromatography ◽  
Support Surface ◽  
Retention Performance ◽  
X Ray Diffraction ◽  
Heterogeneous Distribution ◽  
Solid Extractant ◽  
Extraction Behavior ◽  
Chromatographic Resolution ◽  
Inorganic Supports ◽  
Solid Extractants

Bis(2-ethylhexyl)phosphoric acid (HDEHP) is frequently used as an extractant in the separation and recovery of lanthanides by solvent extraction and extraction chromatography, where HDEHP (stationary phase) is fixed on an inert support and the mobile phase is an aqueous solution. Because the results of extraction chromatography strongly depend on the support material, in this study, we aim to prepare solid extractants (extraction chromatography materials) with different inorganic supports impregnated with HDEHP for the adsorption of Gd and Tb from HCl solutions, putting emphasis on the effect of the supports on the solid extractant behavior. Gd and Tb partition data were determined in HCl solutions from the prepared extraction chromatography materials using elution analysis. Solid extractants were characterized by X-Ray diffraction, electron microscopy, and infrared spectroscopy in order to determine their properties and to explain their extraction behavior. The characterization of the solid extractants showed a heterogeneous distribution of the HDEHP on the surfaces of the different supports studied. The irregular shape of the support particles produces discontinuous and heterogenous silanization and HDEHP coatings on the support surface, affecting the retention performance of the solid extractant and the chromatographic resolution.

In situ x-ray observation of bainitic transformation of austempered silicon alloyed steel

2009 ◽  
Vol 24 (4) ◽  
pp. 1559-1566 ◽  
Author(s):  
Xiang Chen ◽  
Esa Vuorinen
Keyword(s):  
Volume Fraction ◽  
Early Stage ◽  
Bainitic Ferrite ◽  
Bainitic Transformation ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
Heterogeneous Distribution ◽  
X Ray ◽  
Austempering Temperature

The in situ x-ray diffraction observations of the bainitic transformation were conducted by using the high-temperature x-ray diffraction technique. The volume fraction and carbon content of austenite depend on the transformation temperature. The d{110} value of bainitic ferrite decreases with increasing austempering temperature, which is related to the decrease of carbon concentration in bainitic ferrite. Asymmetry diffraction peaks are obtained for samples at the early stage of transformation at any austempering temperatures. This asymmetry diffraction peak after the formation of bainitic ferrite could be attributed to a heterogeneous distribution of carbon in different regions of austenite and show that two types of austenite with different carbon contents, low-carbon austenite (γLC) and the high-carbon austenite (γHC), exist during the transformation. The microstructure after cooling down to room temperature is presented to show the effectiveness of the x-ray diffraction analysis.

Real-time microstructure of shock-compressed single crystals from X-ray diffraction line profiles

2011 ◽  
Vol 44 (3) ◽  
pp. 574-584 ◽  
Author(s):  
Stefan J. Turneaure ◽  
Y. M. Gupta
Keyword(s):  
Single Crystals ◽  
Real Time ◽  
Line Profile ◽  
Distribution Model ◽  
Line Profiles ◽  
X Ray Diffraction ◽  
Multiple Diffraction ◽  
Heterogeneous Distribution ◽  
X Ray ◽  
Experimental Geometry

Methods to obtain and analyze high-resolution real-time X-ray diffraction (XRD) measurements from shock-compressed single crystals are presented. Procedures for extracting microstructural information – the focus of this work – from XRD line profiles are described. To obtain quantitative results, careful consideration of the experimental geometry is needed, including the single-crystal nature of the sample and the removal of instrumental broadening. These issues are discussed in detail. Williamson–Hall (WH) and profile synthesis (PS) analysis procedures are presented. More accurate than WH, the PS procedure relies on a forward calculation in which a line profile is synthesized by convoluting the instrumental line profile with a line profile determined from a diffraction simulation. The diffraction simulation uses the actual experimental geometry and a model microstructure for the shocked crystal. The shocked-crystal microstructural parameters were determined by optimizing the match between the synthesized and measured line profiles. XRD measurements on an Al crystal, shocked along [100] to 7.1 GPa using plate-impact loading, are used to demonstrate the WH and PS analysis methods. In the present analysis, the microstructural line broadening arises because of a distribution of longitudinal elastic microstrains. The WH analysis resulted in FWHM longitudinal microstrain distributions of 0.22 and 0.38% for Lorentzian and Gaussian line shape assumptions, respectively. The optimal FWHM longitudinal microstrain for the PS method was 0.35% with a pseudo-Voigt distribution (40% Lorentzian–60% Gaussian). The line profile measurements and PS analysis presented in this work provide new insight into the heterogeneous distribution of elastic strains in crystals undergoing elastic–plastic deformation during shock compression. Such microstrain distribution measurements are complementary to continuum measurements, which represent averages of the heterogeneous strains or stresses. The PS analysis is a general method capable of incorporating microstructural models more complex than the microstrain distribution model used in this work. As a next step, the PS method will be applied to line profiles of multiple diffraction peaks to separate strain- and size-broadening effects in shocked crystals.

Development and Characterisation of New Biocompatible Sn-Mg Lead-Free Solder

2019 ◽  
Vol 31 ◽  
pp. 6-10
Author(s):  
Martin Ďurišin ◽  
Juraj Ďurišin ◽  
Ondrej Milkovič ◽  
Alena Pietriková ◽  
Karel Saksl
Keyword(s):  
Melt Spinning ◽  
High Energy ◽  
Grain Structure ◽  
Lead Free ◽  
Lead Free Solder ◽  
X Ray Diffraction ◽  
Synchrotron Source ◽  
Heterogeneous Distribution ◽  
X Ray ◽  
Free Solder

This work is focused on a development and research of a new lead-free Sn-Mg solder, alloy compatible with the human body. Tin and magnesium are biocompatible elements which do not cause an inflammation or allergic reactions with living tissues. We have prepared the Sn97Mg3 solder (wt. %) by a rapid solidification of its melt on a copper wheel (melt-spinning technique). This solder may find applications in electronic devices for intracorporeal utilisation. The microstructure of the prepared solder exhibits a heterogeneous distribution of the SnMg2 intermetallic particles within the β-Sn matrix. Structure of the solder was studied by an in-situ high energy X-ray diffraction experiment (energy of an X-ray photon: 60 keV) where 2D XRD patterns were collected from the sample in the temperature range from 298 K to 566 K. The experiment was performed at a high brilliance 3rd generation synchrotron source of radiation (PETRA III storage ring, DESY, Hamburg, Germany) at the P02 undulator beamline. From the measured X-ray diffraction data by applying the Rietveld refinement technique we have obtained thermal volume expansion data, mean positions of atoms as well as isotropic atomic displacement parameters of the constituent SnMg2 and the β-Sn crystalline phases. Thermal behaviour was studied by differential scanning calorimetry at heating rates of 5, 15, 30 and 60 K.min-1 and compared with the measured X-ray data. Our main goal lies in a preparation of a lead-free solder with fine grain structure made exclusively of biocompatible elements. We demonstrated that the rapid melt solidification technique leads to in an improvement and better thermal stability of this alloy.

Extraction Behavior of Americium and Curium on Selected Extraction Chromatography Resins from Pure Acidic Matrices

2014 ◽  
Vol 32 (4) ◽  
pp. 391-407 ◽  
Author(s):  
Narek Gharibyan ◽  
Ashlee Dailey ◽  
Derek R. McLain ◽  
Evelyn M. Bond ◽  
Walter A. Moody ◽  
...  
Keyword(s):  
Extraction Chromatography ◽  
Extraction Behavior

scholarly journals Effect of molar concentration on the optical and structural properties of ZnO thin films prepared by chemical bath deposition method

2020 ◽  
Vol 12 (01) ◽  
pp. 66-72
Author(s):  
Qasim Chfat Abdulridha ◽  
◽  
Hussein Ali Noor ◽  
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Energy Gap ◽  
Hexagonal Structure ◽  
Molar Concentration ◽  
Zno Thin Films ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Heterogeneous Distribution ◽  
Preferred Direction

This research included the preparation of (ZnO) thin films by CBD technique for the deposition of chemical bath thickness (150 ± 20nm). X-ray diffraction was analyzed and showed that the films crystallize in a polycrystalline hexagonal structure, with a preferred direction along the level (100). Increased volume of calculated crystals for deposited films was found by increasing molar concentration. The surface morphology of films was studied by SEM, and the surface morphology of ZnO films is a heterogeneous distribution. The optical properties of all deposited ZnO films contained a spectral permeability and absorption spectrum in the wavelength range (300-1100nm), and the transmittance decreased with increasing molar concentration, it was found that the value of the light energy gap (Eg) increases with increasing molecular concentration band gap between 3.1 and 3.2 eV.

Localization of lipoyl-bearing domains in 2-ketoglutarate dehydrogenase complex by electron microscopy and single-particle averaging methods

1983 ◽  
Vol 41 ◽  
pp. 756-757
Author(s):  
Terence Wagenknecht ◽  
Joachim Frank
Keyword(s):  
Support Surface ◽  
X Ray Diffraction ◽  
X Ray ◽  
E Coli ◽  
Catalytic Function ◽  
Multiple Copies ◽  
Covalently Linked ◽  
Polypeptide Chains ◽  
Dehydrogenase Complex ◽  
Ketoglutarate Dehydrogenase

The 2-ketoglutarate dehydrogenase complex (KGDC) from E. coli (Mr=2.5 x 106) consists of multiple copies of three component enzymes. In addition to its catalytic function one of the components, dihydrolipoyl transsuccinylase (E2), serves as a structural core (Mr=l x 106) to which the other two components are noncovalently bonded. X-ray diffraction studies have shown the E2 complex to be built from 24 identical polypeptide chains and to have the overall shape of a cube having truncated corners. In the electron microscope the E2 complexes adhere preferentially to the support surface by one of their faces and thus appear square-shaped with four morphological units at the vertices and a stain filled center (Fig 1A).Each of the E2 chains contains a lipoic acid cofactor covalently linked to a lysine residue. A domain (Mr=ll,000) containing the lipoyl moiety is removed by trypsin without disrupting the basic architecture of the complex. Micrographs of the trypsin-treated E2 complexes (Fig 1B) appear similar to those of the native complexes (Fig 1A), although the trypsintreated complexes appear slightly smaller and have a more sharply defined 4-fold symmetry.

Production and Characterization of Ti-Nb Alloys, Using Powders Obtained by HDH Process Aiming the Development of Biomaterials

2014 ◽  
Vol 805 ◽  
pp. 331-336
Author(s):  
Murilo de Oliveira Barbosa ◽  
Rodrigo de Sousa e Silva ◽  
Gerson Fernandes Araújo ◽  
Rayana F. Rodrigues Lourenço ◽  
Fernando Vernilli ◽  
...  
Keyword(s):  
Modulus Of Elasticity ◽  
Microstructural Characterization ◽  
X Ray Diffraction ◽  
High Melting Point ◽  
Heterogeneous Distribution ◽  
The Matrix ◽  
Low Modulus ◽  
Low Toxicity ◽  
Reversible Phase

Titanium is a metal that has high melting point 1668 ° C, the boiling point of 3287° C, low density (4.54 g/cm3) and modulus of elasticity around 12.7 MPa x104. However, one of the most important properties is the biocompatibility, which makes this metal to be the most widely used in biomedical. Several alloys were developed using titanium such as the alloy Ti-6Al-4V, however Al and V show toxic characteristics to the organism. The alloy TiNb has been studied to replace the alloy Ti-6Al-4V, because it presents high biocompatibility, low modulus of elasticity, high corrosion resistance and low toxicity. The alloy TiNb can be obtained by conventional melting route or powder metallurgy, where the powders can be obtained by spray drying, chemical reactions and the process of hydrogenation and dehydrogenation (HDH).The hydrogenation is carried out by inserting hydrogen in the structure of Ti and Nb in vacuum at high temperatures, forming a phase extremely fragile called hydride of Ti and Nb, thus enabling the reduction of particle size by milling. Upon heating under vacuum, the hydrogen is extracted to yield the metals Ti and Nb since the hydrogen forms a reversible phase with metals. This work aims the production and characterization of the alloy TiNb where the powders are obtained through the HDH process, varying the concentration of Nb by weight from 10 to 50%.To analyze the morphology and pore size, formation and composition of phases, we used the techniques of microstructural characterization and mechanical by scanning electron microscopy, BET, X-ray diffraction and compression test. The results showed a heterogeneous distribution of Nb in the matrix Ti as well as a decrease in the modulus of elasticity with increase in percentage of Nb.

Preparation of La1−xSrxMnO3 Perovskite Catalysts Supported on Ceramic Foam Materials

1994 ◽  
Vol 368 ◽  
Author(s):  
Z. R. Ismagilov ◽  
O.Yu. Podyacheva ◽  
A.A. Ketov ◽  
A. Bos ◽  
H. J. Veringa
Keyword(s):  
Diffraction Analysis ◽  
Perovskite Phase ◽  
Ceramic Foam ◽  
Support Surface ◽  
X Ray Diffraction ◽  
Active Centers ◽  
X Ray ◽  
Perovskite Catalysts ◽  
Temperature Programmed ◽  
Co Precipitation

ABSTRACTThe new method of preparation of La1−xSrxMnO3 catalysts supported on ceramic foam materials was developed. The synthesized supported perovskite catalysts were examined by X-ray diffraction analysis and BET methods. It was shown that in coated samples there is a pure perovskite phase on the support surface up to temperatures of 1000°C.Unsupported La1−xSrxMnO3 catalysts were synthesized applying co-precipitation technique using La, Sr and Mn acetylacetonates and were studied by X-ray diffraction analysis. Temperature programmed reduction method revealed that catalysts contain 2 types of active centers: low temperature (α) and high temperature (β), the quantity of these centers and correlation between them depend on the value of x. It was shown that supported perovskite catalysts, similarly to the massive ones, maintain two types of active centers (α and β).The activity of La1−xSrxMnO3 on mullite foam was characterized in the methane oxidation reaction.

scholarly journals In Situ High Temperature X-Ray Studies on Bainitic Transformation of Austempered Silicon Alloyed Steels

2010 ◽  
Vol 638-642 ◽  
pp. 3086-3092 ◽  
Author(s):  
Esa Vuorinen ◽  
Xiang Chen
Keyword(s):  
High Temperature ◽  
Volume Fraction ◽  
Early Stage ◽  
Bainitic Transformation ◽  
Experimental Results ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
Heterogeneous Distribution ◽  
X Ray

The in-situ X-ray diffraction observations of the bainitic transformation of silicon alloyed steels were performed using the high temperature X-ray diffraction technique. The experimental results have shown that the volume fraction and carbon content of austenite remains a constant value which indicate that the transformation is almost finished after the early stages of austempering transformation. Asymmetry diffraction peaks are obtained for samples at the early stage of transformation due to a heterogeneous distribution of carbon in different regions of austenite and thus exists two types of austenite: low-carbon austenite (γLC) and the high-carbon austenite (γHC). The experimental results supports that the bainite growth is by a non-diffusive mechanism when austempering temperature is in the lower bainite transformation temperature.

Detailed Characterization of Surface Ln-Doped Anatase TiO2 Nanoparticles by Hydrothermal Treatment for Photocatalysis and Gas Sensing Applications

2015 ◽  
Vol 1806 ◽  
pp. 25-30
Author(s):  
Rezwanur Rahman ◽  
Sean T. Anderson ◽  
Sonal Dey ◽  
Robert A. Mayanovic
Keyword(s):  
Hydrothermal Treatment ◽  
Gas Sensing ◽  
Ambient Air ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Heterogeneous Distribution ◽  
Sensing Applications ◽  
Hole Defects ◽  
Made In

ABSTRACTNanostructured anatase TiO2 is a promising material for gas sensing and photocatalysis. In order to modify its catalytic properties, the lanthanide (Ln) ions Eu3+, Gd3+, Nd3+ and Yb3+ were precipitated on the surface of TiO2 nanoparticles (NPs) by hydrothermal treatment. Results from Raman spectroscopy and X-ray diffraction (XRD) measurements show that the anatase structure of the TiO2 nanoparticles was preserved after hydrothermal treatment. SEM and TEM show a heterogeneous distribution in size and a nanocrystallite morphology of the TiO2 NPs (∼ 14 nm in size) and EDX confirmed the presence of the Ln-ion surface doping after hydrothermal treatment. An increase in photoluminescence (PL) was observed for the Ln-surface-doped TiO2 NPs when measurements were made in forming gas (5% H2 + 95% Ar) at 520 °C. In contrast, the PL measurements made at room temperature did not show any noticeable difference in forming gas or in ambient air. Our temperature-dependent PL results obtained in different gas environments are consistent with modification of oxygen-vacancies and hole-defects due to a combination of hydrothermal treatment and surface Ln-doping.

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