scholarly journals A prototype handheld X-ray diffraction instrument

2018 ◽  
Vol 51 (6) ◽  
pp. 1571-1585 ◽  
Author(s):  
Graeme Hansford

A conceptual design for a handheld X-ray diffraction (HHXRD) instrument is proposed. Central to the design is the application of energy-dispersive XRD (EDXRD) in a back-reflection geometry. This technique brings unique advantages which enable a handheld instrument format, most notably, insensitivity to sample morphology and to the precise sample position relative to the instrument. For fine-grained samples, including many geological specimens and the majority of common alloys, these characteristics negate sample preparation requirements. A prototype HHXRD device has been developed by minor modification of a handheld X-ray fluorescence instrument, and the performance of the prototype has been tested with samples relevant to mining/quarrying and with an extensive range of metal samples. It is shown, for example, that the mineralogical composition of iron-ore samples can be approximately quantified. In metals analysis, identification and quantification of the major phases have been demonstrated, along with extraction of lattice parameters. Texture analysis is also possible and a simple example for a phosphor bronze sample is presented. Instrument formats other than handheld are possible and online process control in metals production is a promising area. The prototype instrument requires extended measurement times but it is argued that a purpose-designed instrument can achieve data-acquisition times below one minute. HHXRD based on back-reflection EDXRD is limited by the low resolution of diffraction peaks and interference by overlapping fluorescence peaks and, for these reasons, cannot serve as a general-purpose XRD tool. However, the advantages ofin situ, nondestructive and rapid measurement, tolerance of irregular surfaces, and no sample preparation requirement in many cases are potentially transformative. For targeted applications in which the analysis meets commercially relevant performance criteria, HHXRD could become the method of choice through sheer speed and convenience.

Author(s):  
F. Mostefa ◽  
Nasr Eddine Bouhamou ◽  
H.A. Mesbah ◽  
Salima Aggoun ◽  
D. Mekhatria

This work aims to study the feasibility of making a geopolymer cement based on dredged sediments, from the Fergoug dam (Algeria) and to evaluate their construction potential particularly interesting in the field of special cementitious materials. These sediments due to their mineralogical composition as aluminosilicates; are materials that can be used after heat treatment. Sedimentary clays were characterized before and after calcination by X-ray diffraction, ATG / ATD, spectroscopy (FTIR) and XRF analysis. The calcination was carried out on the raw material sieved at 80 μm for a temperature of 750 ° C, for 3.4 and 5 hours. The reactivity of the calcined products was measured using isothermal calorimetric analysis (DSC) on pastes prepared by mixing an alkaline solution of sodium hydroxide (NaOH) 8 M in an amount allowing to have a Na / Al ratio close to 1 (1: 1). Also, cubic mortar samples were prepared with a ratio L / S: 0.8, sealed and cured for 24 hours at 60 ° C and then at room temperature until the day they were submited to mechanical testing. to check the extent of geopolymerization. The results obtained allowed to optimize the calcination time of 5 hours for a better reactivity of these sediments, and a concentration of 8M of sodium hydroxide and more suitable to have the best mechanical performances.


Nafta-Gaz ◽  
2021 ◽  
Vol 77 (5) ◽  
pp. 293-298
Author(s):  
Urszula Zagórska ◽  
◽  
Sylwia Kowalska ◽  

The analysis of mineralogical composition by quantitative X-ray diffraction (QXRD) is one of the standard research methods used in hydrocarbon exploration. In order to improve it and to obtain better results, the methodology of quantitative analysis used at Well Logging Department is being periodically (more or less) modified. After the introduction of the improvements, comparative analyses were performed on archival samples. Reflections from an unidentified phase which did not occur in the tested Rotliegend sandstone samples were noticed on X-ray diffractograms of archival samples. Reflections of a mineral called simonkolleite were identified in the X-ray diffraction database. Chemically it is a hydrated zinc chloride of the formula: Zn5Cl2(OH)8 × H2O. Analysis of the composition of samples in which simonkolleite crystallised, indicated that the mineral is being formed in the result of the slow reaction of zinc oxide with halite (NaCl) and water vapour. An attempt was made to determine the influence of the presence of this mineral on the results of the quantitative analysis of mineralogical composition. The above methodology was applied on a group of ten samples. The results of the quantitative analysis conducted for archival samples stored with added zincite standard containing simonkolleite and for new, freshly grinded (without artifact) samples were compared. The comparison of the obtained results showed a slight influence of this mineral on the quantitative composition of the remaining components. The difference between the results usually did not exceed the method error. At the same time a significant difference in the calculated content of the internal standard was noted – on average 1% less in archival than in new samples. This shows that the reaction occurring in the archival samples will affect the evaluation of the quality of the obtained quantitative analysis, at the same time excluding the possibility of determining the rock’s amorphous substance content with the internal standard method.


2007 ◽  
Vol 36 (2) ◽  
pp. 487-497 ◽  
Author(s):  
Dimitris Dermatas ◽  
Maria Chrysochoou ◽  
Sarra Pardali ◽  
Dennis G. Grubb

Clay Minerals ◽  
2017 ◽  
Vol 52 (4) ◽  
pp. 453-468 ◽  
Author(s):  
A. Aras ◽  
S. Kiliç

AbstractThe present study focused on the mineralogical and chemical characterization and firing behaviour of clays from the Lake Van region and compared them with the same characteristics established for two ancient pot sherds. Four pottery clays collected from Kutki and Kuşluk in the Kesan Valley to the south, from Kavakbaşı to the southwest and from Bardakçı village on the east coast of Lake Van were analysed by X-ray diffraction to identify mineralogical composition (bulk clays and <2 μm fractions after heating at 300–500°C and ethylene glycol solvation). Further analyses were conducted to determine the size distribution, chemical composition and physical properties of test bodies derived from these clays. The in situ weathered schist forming the primary micaceous red clays which are suitable for local pottery production are characterized by large muscovite-sericite-illite and small calcite contents. In contrast, the Bardakçı clays are dominated by large smectite contents and are only used sparingly in mixtures of local pottery production because they undergo firing shrinkage and present drying and firing flaws in the fired bodies. Firing ranges of ~800–900°C were inferred from the mineralogy and colours of the two ancient sherds from Kutki. As a result of mineralogical analysis of fired and unfired test bodies of these pottery clays and pot sherds, two different types of pastes were determined for pottery production in the Lake Van region: metamorphic and volcanic paste, the former characterized by a calcite-poor and mica-sericite-rich matrix and the latter by large smectite and small calcite contents.


2010 ◽  
Vol 37-38 ◽  
pp. 64-67
Author(s):  
Jin Song Chen ◽  
Yin Hui Huang ◽  
Bin Qiao ◽  
Jian Ming Yang ◽  
Yi Qiang He

The principles of jet electrodeposition orientated by rapid prototyping were introduced. The nanocrystalline nickel parts with simple shape were fabricated using jet electrodeposition. The microstructure and phase transformation of nanocrystalline nickel were observed under the scanning microscope and X-ray diffraction instrument. The results show that the jet electrodeposition can greatly enhance the limited current density, fine crystalline particles and improve deposition quality. The nickel parts prepared by jet electrodeposition own a fine-grained structure (average grain size 25.6nm) with a smooth surface and high dimensional accuracy under the optimum processing parameters.


1994 ◽  
Vol 9 (1) ◽  
pp. 50-53 ◽  
Author(s):  
Benjamin L. Ballard ◽  
Paul K. Predecki ◽  
Camden R. Hubbard

Residual strains and microstresses are evaluated for both phase of a hot-pressed, fine-grained α-alumina reinforced with 25 wt% (29 vol%) single-crystal silicon carbide whiskers at temperatures from 25 to 1000 °C. The sample was maintained in a nonoxidizing environment while measurements of the interplaner spacing of alumina (146) and SiC (511 + 333) were made using X-ray diffraction methods. The residual strains were profiled at temperature increments of 250 °C from which the corresponding microstresses were calculated. Linear extrapolation of the SiC ε33 profile indicates that the strains are completely relaxed at a temperature of approximately 1470 °C. These residual stress relaxation results suggest that elevated temperature toughness and fracture strength of this composite may result from cooperative mechanisms.


2020 ◽  
Vol 35 (S1) ◽  
pp. S29-S33
Author(s):  
Dieter Ingerle ◽  
Werner Artner ◽  
Klaudia Hradil ◽  
Christina Streli

A commercial Empyrean X-ray diffractometer was adapted for combined grazing incidence X-ray fluorescence analysis (GIXRF) measurements with X-ray reflectivity (XRR) measurements. An energy-dispersive silicon drift detector was mounted and integrated in the angle-dependent data acquisition of the Empyrean. Different monochromator/X-ray optics units have been compared with the values obtained by the Atominstitut GIXRF + XRR spectrometer. Data evaluation was performed by JGIXA, a special software for combined GIXRF + XRR data fitting, developed at Atominstitut. A sample consisting of a ~50 nm nickel layer on a silicon substrate was used to compare the performance criteria (i.e. divergence and intensity) of the incident beam optics. An Empyrean X-ray diffractometer was successfully refitted to measure both GIXRF and XRR data.


Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1488
Author(s):  
Lev B. Zuev ◽  
Galina V. Shlyakhova ◽  
Svetlana A. Barannikova

Radial forging is a reliable way to produce Ti alloy rods without preliminary mechanical processing of their surface, which is in turn a mandatory procedure during almost each stage of the existing technology. In the present research, hot pressing and radial forging (RF) of the titanium-based Ti-3.3Al-5Mo-5V alloy were carried out to study the specifics of plasticized metal flow and microstructural evolution in different sections of the rods. The structural analysis of these rods was performed using metallography and X-ray diffraction techniques. The X-ray diffraction reveals the two-phase state of the alloy. The phase content in the alloy was shown to vary upon radial forging. Finally, radial forging was found to be a reliable method to achieve the uniform fine-grained structure and high quality of the rod surface.


2014 ◽  
Vol 21 (6) ◽  
pp. 1378-1383 ◽  
Author(s):  
Yuki Sekiguchi ◽  
Masaki Yamamoto ◽  
Tomotaka Oroguchi ◽  
Yuki Takayama ◽  
Shigeyuki Suzuki ◽  
...  

Using our custom-made diffraction apparatus KOTOBUKI-1 and two multiport CCD detectors, cryogenic coherent X-ray diffraction imaging experiments have been undertaken at the SPring-8 Angstrom Compact free electron LAser (SACLA) facility. To efficiently perform experiments and data processing, two software suites with user-friendly graphical user interfaces have been developed. The first is a program suite namedIDATEN, which was developed to easily conduct four procedures during experiments: aligning KOTOBUKI-1, loading a flash-cooled sample into the cryogenic goniometer stage inside the vacuum chamber of KOTOBUKI-1, adjusting the sample position with respect to the X-ray beam using a pair of telescopes, and collecting diffraction data by raster scanning the sample with X-ray pulses. NamedG-SITENNO, the other suite is an automated version of the originalSITENNOsuite, which was designed for processing diffraction data. These user-friendly software suites are now indispensable for collecting a large number of diffraction patterns and for processing the diffraction patterns immediately after collecting data within a limited beam time.


1980 ◽  
Vol 24 ◽  
pp. 239-243
Author(s):  
O. W. Marks ◽  
D. K. Smith ◽  
M. D. Chris

Separating overlapped peaks is a part of many x-ray diffraction analyses, for example, polymer crystallinity. Natta [1] defined a method for polypropylene in 1957. His method was computerized at the Hercules Research Center in 1960 with an automatic “curve follower” which punched paper tape for the computer. A later method deviated fTom Natta's method by approximating the amorphous curve with a fixed shape and a height chosen to best fit the diffraction data from 2θ = 7.5 through 10. degrees. Neither of these methods worked on “smectic” polymer samples, i.e., composed of very small crystallites. Also, a different computer program was used for each different polymer, so a general purpose computer program was developed using a peak profile method. This method has been used en polymer mixtures and copolymers of ethylene, propylene, and butene; and on cellulose, modified cellulose, and catalysts. The selection of a profile function is discussed in the next section. In later sections, the background, the fitting procedure, and computer input and output are discussed.


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