scholarly journals Quantitative Microstructural Analysis and X-ray Computed Tomography of Ores and Rocks—Comparison of Results

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 129 ◽  
Author(s):  
Oleg Popov ◽  
Irina Talovina ◽  
Holger Lieberwirth ◽  
Asiia Duriagina
Keyword(s):  
Sample Preparation ◽  
Microstructural Analysis ◽  
Copper Ore ◽  
Profound Knowledge ◽  
Special Distribution ◽  
X Ray Computed ◽  
Quantitative Results ◽  
External Loads ◽  
Modelling Simulation ◽  
Good Agreement

Profound knowledge of the structure and texture of rocks and ores as well as the behavior of the materials under external loads is essential to further improvements in size reduction processes, particularly in terms of liberation size. New analytical methods such as computer tomography (CT) were adopted to improve the understanding of material characteristics in rocks and ores relevant to mineral processing, particular the crushing and grinding and the modelling/simulation thereof. Results obtained on the texture and structure of identical samples of rather different rocks and ores (copper ore, granodiorite, kimberlite) are compared by CT with quantitative results from traditional optical microscopy obtained by quantitative microstructural analysis (QMA). While the two approaches show a good agreement of the results in many areas, the measurements with the two different methods also exhibit remarkable differences in other areas, which are discussed further. In conclusion, both methods have their specific advantages starting from sample preparation to the accuracy of information obtained concerning certain parameters of mode and fabric. While sample preparation is faster with CT and information on special distribution of metal minerals is more reliable, the information on mode, grain size and clustering seem to be more precise with QMA. Based on the results, it can be concluded that both methods are comparable in many areas, but in in the field of spatial distribution, they are merely complementary.

scholarly journals An X-ray CT study of miniature clay sample preparation techniques

2019 ◽  
Vol 92 ◽  
pp. 01004
Author(s):  
Christopher Ibeh ◽  
Matteo Pedrotti ◽  
Alessandro Tarantino ◽  
Rebecca Lunn
Keyword(s):  
Sample Preparation ◽  
Shear Plane ◽  
Cohesive Soil ◽  
Image Resolution ◽  
Particle Orientation ◽  
X Ray ◽  
High Resolution Images ◽  
X Ray Computed ◽  
Sample Disturbance ◽  
Relationship Of

The quality and reliability of cohesive soil laboratory test data can be significantlyaffected by sample disturbance during sampling or sample preparation. Sample disturbance may affect key design and modelling parameters such as stiffness, preconsolidation stress, compressibility and undrained shear strength, and ultimately determine particle mobilization and shear plane development. The use of X-ray computed tomography (X-CT) in the study of soil is restricted by the inverse relationship of specimen size and obtainable image resolution. This has led to the testing of miniature specimen sizes which are far less than conventional laboratory sample size in a bid to obtain high resolution images and detailed particle-scale soil properties; however, these miniature soil specimens are more prone to sample disturbance. In this work 2% muscovite was mixed with speswhite kaolin clay as a strain marker for use in X-CT. The clay soil sample was prepared from slurry and either consolidated using an oedometer or a gypsum mould. Specimens obtained from a 7 mm tube sampler were compared to lathe trimmed specimens with a diameter (Ø) of 7 mm. Results from X-CT imaging were used to study the influence of sampler type on specimen disturbance, by analysing the muscovite particle orientation of the obtained 3D images. The results show that; for samples subjected to large consolidation stress (>200kpa) lathe trimmed specimens may be subject to lesser disturbance compared to tube sampled specimens.

scholarly journals Design, Synthesis, Biological Evaluation, and Computational Studies of Novel Tri-Aryl Imidazole-Benzene Sulfonamide Hybrids as Promising Selective Carbonic Anhydrase IX and XII Inhibitors

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4718
Author(s):  
Lamya H. Al-Wahaibi ◽  
Bahaa G. M. Youssif ◽  
Ehab S. Taher ◽  
Ahmed H. Abdelazeem ◽  
Antar A. Abdelhamid ◽  
...  
Keyword(s):  
Proliferative Activity ◽  
Docking Studies ◽  
Biological Evaluation ◽  
Selectivity Ratio ◽  
Computational Studies ◽  
Design Synthesis ◽  
Ca Ix ◽  
Side Pocket ◽  
Modelling Simulation ◽  
Good Agreement

A novel series of tri-aryl imidazole derivatives 5a–n carrying benzene sulfonamide moiety has been designed for their selective inhibitory against hCA IX and XII activity. Six compounds were found to be potent and selective CA IX inhibitors with the order of 5g > 5b > 5d > 5e > 5g > 5n (Ki = 0.3–1.3 μM, and selectivity ratio for hCA IX over hCA XII = 5–12) relative to acetazolamide (Ki = 0.03 μM, and selectivity ratio for hCA IX over hCA XII = 0.20). The previous sixth inhibitors have been further investigated for their anti-proliferative activity against four different cancer cell lines using MTT assay. Compounds 5g and 5b demonstrated higher antiproliferative activity than other tested compounds (with GI50 = 2.3 and 2.8 M, respectively) in comparison to doxorubicin (GI50 = 1.1 M). Docking studies of these two compounds adopted orientation and binding interactions with a higher liability to enter the active side pocket CA-IX selectively similar to that of ligand 9FK. Molecular modelling simulation showed good agreement with the acquired biological evaluation.

Agreement and reliability of magnetic, angular rate, and gravity (MARG) sensors to assess multiple body segment’s external loads during off-road running

2021 ◽  
pp. 175433712199698
Author(s):  
Daniel Rojas-Valverde ◽  
José Pino-Ortega ◽  
Rafael Timón ◽  
Randall Gutiérrez-Vargas ◽  
Braulio Sánchez-Ureña ◽  
...  
Keyword(s):  
Vastus Lateralis ◽  
Angular Rate ◽  
Wearable Sensors ◽  
Intraclass Correlation ◽  
Principal Component ◽  
Test Reliability ◽  
Data Set ◽  
Body Segments ◽  
External Loads ◽  
Good Agreement

The extensive use of wearable sensors in sport medicine, exercise medicine, and health has increased the interest in their study. That is why it is necessary to test these technologies’ efficiency, effectiveness, agreement, and reliability in different settings. Consequently, the purpose of this article was to analyze the magnetic, angular rate, and gravity (MARG) sensor’s test-retest agreement and reliability when assessing multiple body segments’ external loads during off-road running. A total of 18 off-road runners (38.78 ± 10.38 years, 73.24 ± 12.6 kg, 172.17 ± 9.48 cm) ran two laps (1st and 2nd Lap) of a 12 km circuit wearing six MARG sensors. The sensors were attached to six different body segments: left (MPLeft) and right (MPRight) malleolus peroneus, left (VLLeft) and right (VLRight) vastus lateralis, lumbar (L1-L3), and thorax (T2-T4) using a special neoprene suit. After a principal component analysis (PCA) was performed, the total data set variance of all body segments was represented by 44.08%–70.64% for the 1st PCA factor considering two variables, Player LoadRT and Impacts, on L1-L3, respectively. These two variables were chosen among three total accelerometry-based external load indicators (ABELIs) to perform the agreement and reliability tests due to their relevance based on PCAs for each body segment. There were no significant differences between laps in the Player LoadRT or Impacts ( p > 0.05, trivial). The intraclass correlation and lineal correlation showed a substantial to almost perfect over-time test consistency assessed via reliability in both Player LoadRT and Impacts. Bias and t-test assessments showed good agreement between Laps. It can be concluded that MARGs sensors offer significant test re-test reliability and good agreement when assessing off-road kinematics in the six different body segments.

scholarly journals Morphometric Analysis of One-Component Polyurethane Foams Applicable in the Building Sector via X-ray Computed Microtomography

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1717
Author(s):  
Aurelia Blazejczyk
Keyword(s):  
Morphometric Analysis ◽  
Microstructural Analysis ◽  
Total Solid ◽  
Foam Cells ◽  
Polyurethane Foams ◽  
Solid Matrix ◽  
X Ray ◽  
3D Image Reconstruction ◽  
Computed Microtomography ◽  
X Ray Computed

A detailed morphometric analysis of one-component polyurethane (PU) expanding foams, with densities of 26 and 28 kg/m3 (‘SUMMER’ and ‘WINTER’ product versions), was conducted to evaluate the topology of the foam cells and to discover processing-to-structure relationships. The microstructural analysis of the heterogeneously distributed pores revealed tight relationships between the foam morphology and the cell topology, depending on the growth rate and local environmental conditions, governed by the properties of the blowing gas used. The most significant morphometric output included the following: open/closed porosity and (heterogeneous) pore distribution, relative density and (homogeneous) strut distribution, and total solid matrix surface and closed pore surface area—at the macroscopic level of the foam. While, at the microscopic level of the cells, the results embraced the following: the size of every detected strut and pore, identified two-dimensional (2D) shapes of the cell faces, and proposed three-dimensional (3D) topologies modelling the PU foam cells. The foam microstructure could be then related with macroscopic features, significant in building applications. Our protocol outlines the common procedures that are currently used for the sample preparation, X-ray scanning, 3D image reconstruction and dataset analysis in the frame of the X-ray computed microtomography (µ-CT) testing of the one-component PU foams, followed by a statistical (multiple Gaussian) analysis and conceptual considerations of the results in comparison with thematic literature.

Analysis of the sample preparation methods based on piecewise variation coefficients of component mass fractions

2021 ◽  
pp. 15-19
Author(s):  
V. Z. Kozin ◽  
A. S. Komlev ◽  
E. V. Stupakova
Keyword(s):  
Sample Preparation ◽  
Relative Error ◽  
Preparation Method ◽  
Sampling Error ◽  
Theoretical Description ◽  
Random Errors ◽  
Copper Ore ◽  
Preparation Methods ◽  
Mass Fractions ◽  
Sample Preparation Methods

Sample preparation methods are usually developed following respective recommendations of the applicable sampling standards. Modern sampling theories allow designing and optimizing these methods. Random errors in sample preparation are calculated based on a theoretical description of the piecewise heterogeneity of the sample obtained using the formulas for the fundamental sampling error. The concept of a piecewise coefficient of variation is introduced and used to develop a formula for the relative error of the sample preparation method. Using a method compiled in accordance with GOST 14180-80 for copper ore as an example, the relative error is established for the preparation of an ore sample with the copper mass fraction of 1.3 %. It is shown that a change in the final preparation size from 0.1 to 0.08 mm affects the error only insignificantly, and sample size changes by stages allow designing a preparation method with the smallest error. It is advisable to analyze the method compiled and change its parameters on the basis of a structural assessment of the influence of individual preparation stages on the error. Sample preparation examples for copper and gold-bearing ore are used to demonstrate the analysis procedure and the parameter changes. Traditionally, the minimum sample masses are established for all stages based on the volumetric heterogeneity of the sample being tested and the size of the sample material. The minimum masses should be found depending on the grain size of the valuable mineral in the ore, the permissible relative error for the size reduction, and the material size for the sample reduced by a factor of 1.5 for nonferrous metal ores.

Identifying Challenges and Risks Associated with the Analysis of Major Mycotoxins in Feed and Botanicals

2019 ◽  
Vol 102 (6) ◽  
pp. 1689-1694
Author(s):  
Ujwal S. Patil ◽  
Sarah King ◽  
Sean Holleran ◽  
Kristen White ◽  
Cheryl Stephenson ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Weather Conditions ◽  
Herbal Products ◽  
Pros And Cons ◽  
Mycotoxin Analysis ◽  
Quantitative Results ◽  
Traditional Approaches ◽  
The Impact ◽  
Lc Tandem Ms ◽  
Preparation Techniques

Changing weather conditions have heightened the risk of growth of mycotoxigenic molds on crops and various agricultural commodities. Mycotoxins, which are linked to carcinogenic and nephrotoxic effects in animals and humans, have been traditionally analyzed by immunoassays, gas, and LC techniques with spectrophotometric detectors. This review discusses the current techniques and challenges in commercial settings associated with the analysis of mycotoxins in unique matrices such as animal feeds, herbal products, and dietary supplements containing botanicals. Because of the advantages and growing acceptance of LC-tandem MS (MS/MS) over traditional approaches, discussion is mainly based on LC-MS/MS-based approaches. Considering the impact of sample preparation on accuracy of quantitative results, discussion about pros and cons of recently introduced sample preparation techniques is integrated with analytical methods. A section of the review explains the importance and availability of reference materials for mycotoxins. The present discussion provides good insight into the current challenges and developments during mycotoxin analysis of feed and botanicals and addresses the need for researchers in terms of an official MS-based method.

Downshifting Control Strategy for Dual Clutch Transmission With Single Clutch Slippage

2016 ◽  
Author(s):  
Jikai Liu ◽  
Biao Ma ◽  
Heyan Li ◽  
Man Chen ◽  
Jianwen Chen
Keyword(s):  
Control Strategy ◽  
Control Strategies ◽  
Bench Test ◽  
Dual Clutch Transmission ◽  
Pressure Profiles ◽  
Simulation Results ◽  
And Control ◽  
Engagement And Disengagement ◽  
External Loads ◽  
Good Agreement

The cooperation mode between the engagement and disengagement clutches for vehicles equipped with Dual Clutch Transmission (DCT) is of vital importance to achieve a smooth gearshift, in particular for the downshift process as its unavoidable power interruption during the inertia phase. Hence, to elevate the performance of DCT downshifting process, an analytical model and experimental validation for the analysis, simulation and control strategy are presented. Optimized pressure profiles applied on two clutches are obtained based on the detailed analysis of downshifting process. Then, according to the analysis results, a novel control strategy that can achieve downshift task with only one clutch slippage is proposed. The system model is established on Matlab/Simulink platform and used to study the variation of output torque and speed in response to different charging pressure profiles and various external loads during downshifting process. Simulation results show that, compared with conventional control strategies, the proposed one can not only avoid the torque hole and power circulation, but shorten the shift time and reduce the friction work. Furthermore, to validate the effectiveness of the control strategy, the bench test equipped with DCT is conducted and the experiment results show a good agreement with the simulation results.

scholarly journals Microstructural analysis of TRISO particles using multi-scale X-ray computed tomography

2015 ◽  
Vol 461 ◽  
pp. 29-36 ◽  
Author(s):  
T. Lowe ◽  
R.S. Bradley ◽  
S. Yue ◽  
K. Barii ◽  
J. Gelb ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Microstructural Analysis ◽  
X Ray ◽  
Multi Scale ◽  
X Ray Computed ◽  
Triso Particles

Comparison of Sample Preparation Methods for Phosphorus in Grains and Stock Feeds

1968 ◽  
Vol 51 (4) ◽  
pp. 771-773
Author(s):  
Aaron E Rash
Keyword(s):  
Sample Preparation ◽  
Perchloric Acid ◽  
Sodium Molybdate ◽  
The Other ◽  
Acid Digestion ◽  
Preparation Methods ◽  
Commercial Feeds ◽  
Sample Preparation Methods ◽  
Good Agreement

Abstract The nitric-perchloric acid digestion, 22.070(b) and 22.073, for the determination of phosphorus in grains and stock feeds was compared with three other methods of sample preparation (destruction of organic material) : quinoline molybdate precipitation, perchloric-sulfuric-sodium molybdate digestion, and the plant method. The values obtained by the nitric-perchloric acid method were not in good agreement with those obtained by the other methods studied. Six samples of commercial feeds and one barley sample were analyzed. The barley sample gave very poor recoveries by method 22.073.

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