scholarly journals Structural Properties Ni20Cr10Al2Y Coatings for Geothermal Conditions

Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1434 ◽  
Author(s):  
Aurelian Buzaianu ◽  
Petra Motoiu ◽  
Ioana Csaki ◽  
Anghel Ioncea ◽  
Vlad Motoiu
Keyword(s):  
Carbon Steel ◽  
Chemical Properties ◽  
Mechanical Tests ◽  
Steel Plates ◽  
Geothermal System ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
Protective Layers ◽  
Diffraction Patterns ◽  
Oxygen Fuel

The chromium carbide hard phases powders are used for the high velocity oxygen fuel (HVOF) coating technique. This paper investigates samples coated with Ni20Cr10Al2Y on carbon steel plates. The coatings were designed to improve the erosion corrosion properties of carbon steel. The specific agglomerated nanosized Cr3C2 particles on the coated layer provide new physical, mechanical and chemical properties. The multilayer composite technique could be successfully used to protect turbine working in geothermal system. The samples were investigated using nanoindentation to determine the coated samples mechanical properties. The experimental procedure involved obtaining X-ray diffraction patterns of the specimens, micro mechanical tests and SEM investigation to provide detailed information about adhesion of protective layers and morphological modifications.

scholarly journals Born out of Fire and Ice: Polymorph Studies of the Antiviral Famciclovir

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 129
Author(s):  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Variable Temperature ◽  
Chemical Properties ◽  
Crystal Form ◽  
X Ray Diffraction ◽  
Crystal Forms ◽  
X Ray ◽  
Physical Chemical ◽  
Diffraction Patterns ◽  
Crystalline Forms

There is much interest and focus on solid forms of famciclovir. However, in spite of the abundance of reported differences in oral bioavailability, compressibility, and other physical–chemical properties of the various crystal forms of this drug, very little precise structural analysis is available in the literature to date. The form used in the commercial formulation is the anhydrous form I. Patents and patent applications report three different anhydrous crystalline forms on the basis of unindexed powder diffraction patterns. Single-crystal and variable-temperature X-ray diffraction experiments using the commercially available anhydrous form of famciclovir were carried out and led not only to the crystal structure determination of the anhydrous form I, but also to discovery of a new crystal form of anhydrous famciclovir from powder data.

scholarly journals Pitting Corrosion and Microstructure of J55 Carbon Steel Exposed to CO2/Crude Oil/Brine Solution under 2–15 MPa at 30–80 °C

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2374 ◽  
Author(s):  
Haitao Bai ◽  
Yongqing Wang ◽  
Yun Ma ◽  
Peng Ren ◽  
Ningsheng Zhang
Keyword(s):  
Carbon Steel ◽  
Crude Oil ◽  
Energy Dispersive Spectrometer ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
Brine Solution ◽  
Maximum Value ◽  
Production Wells ◽  
Well Depth

This study aimed to evaluate the corrosion properties of J55 carbon steel immersed in CO2/crude oil/brine mixtures present in the wellbores of CO2-flooded production wells. The main corroded position of wellbore was determined and wellbore corrosion law was provided. Corrosion tests were performed in 30% crude oil/brine solution under the simulated temperature (30–80 °C) and pressure (2–15 MPa) conditions of different well depths (0–1500 m). The corrosion behavior of J55 carbon steel was evaluated through weight-loss measurements and surface analytical techniques, including scanning electron microscopy, energy dispersive spectrometer, X-ray diffraction analysis, and optical digital microscopy. Corrosion rate initially increased and then decreased with increasing well depth, which reached the maximum value of 1050 m. At this well depth, pressure and temperature reached 11 MPa and 65 °C, respectively. Under these conditions, FeCO3 and CaCO3 localized on sample surfaces. Microscopy was performed to investigate corrosion depth distribution on the surfaces of the samples.

SOME NEW FLUORIDE COMPLEXES OF TRIVALENT TITANIUM

1958 ◽  
Vol 36 (4) ◽  
pp. 615-622 ◽  
Author(s):  
Norman F. H. Bright ◽  
Joseph G. Wurm
Keyword(s):  
Chemical Properties ◽  
Inert Atmosphere ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Fluoride Complexes ◽  
Diffraction Patterns ◽  
Face Centered ◽  
Physical And Chemical ◽  
Colored Compound ◽  
Trivalent Titanium

Three new complex fluorides of trivalent titanium have been isolated from the products of electrolysis, under an inert atmosphere, of molten baths of KC1, NaCl, or mixtures of KCl and NaCl, containing either K2TiF6 or Na2TiF6. Electrolytic baths containing a mixture of KCl and NaCl with either K2TiF6 or Na2TiF6 yielded a violet-colored, face-centered cubic compound identified as K2NaTiF6, which was virtually insoluble in water and amenable to electrostatic separation from the metallic titanium also produced in the electrolysis. Baths containing molten mixtures of K2TiF6 and KCl gave a pale violet compound K3TiF6, which was slightly soluble in water. Baths containing Na2TiF6 and NaCl gave a deep violet-colored compound Na3TiF6 which was almost insoluble in water. The compounds K3TiF6 and Na3TiF6 have structures which approximate to cubic. The compounds K2NaTiF6 and Na3TiF6 are more stable to atmospheric oxidation than is K3TiF6. X-Ray diffraction patterns have been recorded for these compounds and some of their physical and chemical properties determined.

CHEMICAL PROPERTIES OF CHAMPLAIN SEA SEDIMENTS

1965 ◽  
Vol 2 (4) ◽  
pp. 299-308 ◽  
Author(s):  
R. S. La Venture ◽  
B. P. Warkentin
Keyword(s):  
Chemical Properties ◽  
Exchange Capacity ◽  
Mineral Surfaces ◽  
X Ray Diffraction ◽  
X Ray ◽  
Preferential Adsorption ◽  
Monovalent Ions ◽  
Diffraction Patterns ◽  
Soluble Components

Measurements of soluble components, and characterization of the charge on the mineral surfaces, are reported for five samples of the Champlain Sea sediments. Large amounts of magnesium, beyond the amount of dolomite present, were slowly released in solution from the broken surfaces of the minerals. Amorphous aluminosilicates made up less than 6% of the sample weight, and their removal did not improve the X-ray diffraction patterns or alter significantly the chemical properties of the sediments. Of the cation exchange capacity of 20 to 30 meq/100 g at pH 7, from 50 to 75% was found to be due to pH-dependent charge, which leads to preferential adsorption of monovalent ions. In equilibrium with artificial seawater, the samples had from 50 to 25% exchangeable sodium.

scholarly journals Characterization of Corrosion Products on Carbon Steel Exposed to Natural Weathering and to Accelerated Corrosion Tests

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Renato Altobelli Antunes ◽  
Rodrigo Uchida Ichikawa ◽  
Luis Gallego Martinez ◽  
Isolda Costa
Keyword(s):  
Carbon Steel ◽  
Atmospheric Corrosion ◽  
Corrosion Products ◽  
Steel Plates ◽  
Natural Weathering ◽  
Poor Correlation ◽  
X Ray Diffraction ◽  
Accelerated Corrosion ◽  
Corrosion Tests ◽  
Accelerated Corrosion Tests

The aim of this work was to compare the corrosion products formed on carbon steel plates submitted to atmospheric corrosion in urban and industrial atmospheres with those formed after accelerated corrosion tests. The corrosion products were characterized by X-ray diffraction, Mössbauer spectroscopy, and Raman spectroscopy. The specimens were exposed to natural weathering in both atmospheres for nine months. The morphologies of the corrosion products were evaluated using scanning electron microscopy. The main product found was lepidocrocite. Goethite and magnetite were also found on the corroded specimens but in lower concentrations. The results showed that the accelerated test based on the ASTM B117 procedure presented poor correlation with the atmospheric corrosion tests whereas an alternated fog/dry cycle combined with UV radiation exposure provided better correlation.

Crystal Structure Data for Efavirenz (Sustiva™) by Combined Synchrotron X-Ray Diffraction and Electron Microscopy Techniques

2001 ◽  
Vol 7 (S2) ◽  
pp. 630-631
Author(s):  
Z. G. Li ◽  
R. L. Harlow ◽  
W. Marshell ◽  
C. M. Foris ◽  
D. Murphy ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Crystal Form ◽  
Transcriptase Inhibitor ◽  
Process Conditions ◽  
X Ray Diffraction ◽  
Synthetic Process ◽  
X Ray ◽  
Cell Parameters ◽  
Solvate Form ◽  
Diffraction Patterns

Efavirenz (Sustiva™) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) for the treatment of HrV-infected patients and has been in the market since 1998. Efavirenz exists as three different polymorphs (Forms I, II, III) and a nonstochiometric heptane solvate (Form IV). The current synthetic process for Efavirenz yields Form IV which is converted to the desired Form I polymorph by heating. One of the concerns for any drug substance is whether a consistent crystal form is produced in order to insure consistent physical and chemical properties, as well as to safeguard pharmacokinetic profiles. The sensitivity and resolution of single-crystal x-ray diffraction, the traditional method employed to determine unit cell parameters of drug compounds in development, are limited for Efavirenz Form IV because of the small crystallite size of the material. Furthermore, Efavirenz Form IV materials, depending on the process conditions, have slightly different powder diffraction patterns in terms of intensity when collected on standard in-house diffractometers.

Possible effects of irrigation with wastewater on the clay mineralogy of some Australian clayey soils: laboratory study

Soil Research ◽  
2016 ◽  
Vol 54 (7) ◽  
pp. 857 ◽  
Author(s):  
Serhiy Marchuk ◽  
Jock Churchman ◽  
Pichu Rengasamy
Keyword(s):  
Chemical Composition ◽  
Chemical Properties ◽  
Clay Mineralogy ◽  
Clayey Soils ◽  
X Ray Diffraction ◽  
X Ray ◽  
Physico Chemical ◽  
Soil Clays ◽  
Diffraction Patterns ◽  
Peak Decomposition

Potassium is common in a wide variety of wastewaters and in some wastewaters is present at several hundred to several thousand mg L–1. Potassium is taken up by expandable clays leading to its fixation and illitisation of smectitic and vermiculitic layers. Hence the addition of wastewaters to soils may lead to mineralogical changes in the soils that affect their physico-chemical properties. Winery wastewater was equilibrated with clay-rich soils from Southern Australia. X-ray diffraction patterns and chemical composition of clays extracted from untreated and treated soils were determined. In three of the four soils, shifts in peak positions occurred towards more illitic components along with increases in K and sometimes also Mg and Na contents of soil clays. Peak decomposition showed trends towards the formation of interstratifications of illite with smectite at the expense of smectite and an alteration of poorly crystallised illite into its more well-ordered forms. The results show that illitisation may occur as a result of the addition of K-rich wastewaters to clayey soils.

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

Examination of Rabbit Fc Crystals

1968 ◽  
Vol 26 ◽  
pp. 140-141
Author(s):  
J. P. Robinson ◽  
P. G. Lenhert
Keyword(s):  
Molecular Weight ◽  
Flat Plate ◽  
Phosphate Buffer ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutral Ph ◽  
Small Crystals ◽  
Carbon Coated ◽  
Diffraction Patterns

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.

Quantitative Electron Microscope with imaging plate

1994 ◽  
Vol 52 ◽  
pp. 408-409
Author(s):  
D. Shindo
Keyword(s):  
Electron Microscope ◽  
Dynamic Range ◽  
Processing System ◽  
Digital Data ◽  
Imaging Plate ◽  
Crystal Thickness ◽  
X Ray Diffraction ◽  
Resolution Electron ◽  
Electron Intensity ◽  
Diffraction Patterns

Imaging plate has good properties, i.e., a wide dynamic range and good linearity for the electron intensity. Thus the digital data (2048x1536 pixels, 4096 gray levels in log scale) obtained with the imaging plate can be used for quantification in electron microscopy. By using the image processing system (PIXsysTEM) combined with a main frame (ACOS3900), quantitative analysis of electron diffraction patterns and high-resolution electron microscope (HREM) images has been successfully carried out.In the analysis of HREM images observed with the imaging plate, quantitative comparison between observed intensity and calculated intensity can be carried out by taking into account the experimental parameters such as crystal thickness and defocus value. An example of HREM images of quenched Tl2Ba2Cu1Oy (Tc = 70K) observed with the imaging plate is shown in Figs. 1(b) - (d) comparing with a structure model proposed by x-ray diffraction study of Fig. 1 (a). The image was observed with a JEM-4000EX electron microscope (Cs =1.0 mm).

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