scholarly journals The Role of Soil Mineralogy, Geochemistry and Grain Size in the Development of Mediterranean Badlands: A Review

Author(s):  
Vito Summa ◽  
Maria Luigia
Keyword(s):  

Wear ◽  
2021 ◽  
pp. 203678
Author(s):  
Vahid Javaheri ◽  
Oskari Haiko ◽  
Saeed Sadeghpour ◽  
Kati Valtonen ◽  
Jukka Kömi ◽  
...  


2017 ◽  
Vol 18 (12) ◽  
pp. 4342-4355 ◽  
Author(s):  
Andrew J. Turner ◽  
Richard F. Katz ◽  
Mark D. Behn ◽  
Tobias Keller


Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1019 ◽  
Author(s):  
Angella ◽  
Donnini ◽  
Ripamonti ◽  
Górny ◽  
Zanardi

Tensile testing on ductile iron GJS 400 with different microstructures produced through four different cooling rates was performed in order to investigate the relevance of the microstructure’s parameters on its plastic behaviour. Tensile flow curve modelling was carried out with the Follansbee and Estrin-Kocks-Mecking approach that allowed for an explicit correlation between plastic behaviour and some microstructure parameters. In the model, the ferritic grain size and volume fraction of pearlite and ferrite gathered in the first part of this investigation were used as inputs, while other parameters, like nodule count and interlamellar spacing in pearlite, were neglected. The model matched very well with the experimental flow curves at high strains, while some mismatch was found only at small strains, which was ascribed to the decohesion between the graphite nodules and the ferritic matrix that occurred just after yielding. It can be concluded that the plastic behaviour of GJS 400 depends mainly on the ferritic grain size and pearlitic volume fraction, and other microstructure parameters can be neglected, primarily because of their high nodularity and few defects.



1994 ◽  
Vol 77 (7) ◽  
pp. 1928-1938 ◽  
Author(s):  
Desiderio Kovar ◽  
Michael J. Readey


2021 ◽  
Vol 30 (2) ◽  
pp. 215-225
Author(s):  
Marthe Kretzschmar

Knowledge of the materiality of stone during the Enlightenment expanded following the exploration of mineralogical structure, to alter ideas about taxonomy and challenge the role of rocks in the history of the earth. Close studies of the material of marble sculpture generated expertise on grain size, surface varieties and stone deposits. This mode of reception became intertwined with contemporary controversies about the age of the earth. This article focuses on both French sculpture and geological discourses of the eighteenth century to reveal an international and interdisciplinary network centring on protagonists such as Denis Diderot, Paul-Henri Thiry d’Holbach and Étienne-Maurice Falconet; through these figures, debates can be connected concerning both geology and art theory. Within these contexts, the article discusses the translation processes between these artistic and geological interests.



Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 369 ◽  
Author(s):  
Mo Ji ◽  
Claire Davis ◽  
Martin Strangwood

This paper discusses the role of grain size distribution on the recrystallisation rates and Avrami values for a Fe-30 wt. % Ni steel, which was used as a model alloy retaining an austenitic structure to room temperature. Cold deformation was used to provide uniform macroscopic strain distributions (strains of 0.2 and 0.3), followed by recrystallisation during annealing at 850–950 °C. It was shown that the Avrami parameter was directly related to the grain size distribution, with a lower Avrami exponent being seen for a larger average and wider grain size distribution. A method to predict the Avrami exponent from the grain size distribution was proposed. In situ heating in an SEM with EBSD showed the recrystallisation kinetics to be affected by differences in stored energy and nucleation in the different grain sizes supporting the proposed relationship.



Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1282 ◽  
Author(s):  
Giuliano Angella ◽  
Dario Ripamonti ◽  
Marcin Górny ◽  
Stefano Masaggia ◽  
Franco Zanardi

A series of samples made of ductile iron GJS 400 was cast with different cooling rates, and their microstructural features were investigated. Quantitative metallography analyses compliant with ASTM E2567-16a and ASTM E112-13 standards were performed in order to describe graphite nodules and ferritic grains. The occurrence of pearlite was associated to segregations described through Energy Dispersive X-ray Spectroscopy (EDS) analyses. Results were related to cooling rates, which were simulated through MAGMASOFT software. This microstructural characterization, which provides the basis for the description and modeling of the tensile properties of GJS 400 alloy, subject of a second part of this investigation, highlights that higher cooling rates refines microstructural features, such as graphite nodule count and average ferritic grain size.



2020 ◽  
Vol 57 (10) ◽  
pp. 1508-1517
Author(s):  
L.A. Torres-Cruz ◽  
J.C. Santamarina

The probability of failure of tailing dams and associated risks demand improvements in engineering practice. The critical state line provides a robust framework for the characterization of mine tailings. New experimental data for nonplastic platinum tailings and a large database for tailings and nonplastic soils (grain size between 2 and 500 μm) show that the critical state parameters for nonplastic tailings follow the same trends as nonplastic soils as a function of particle-scale characteristics and extreme void ratios. Critical state lines determined for extreme tailings gradations underestimate the range of critical state parameters that may be encountered in a tailings dam; in fact, mixtures with intermediate fines content exhibit the densest granular packing at critical state. The minimum void ratio emin captures the underlying role of particle shape and grain size distribution on granular packing and emerges as a valuable index property to inform sampling strategies for the assessment of spatial variability. Mineralogy does not significantly affect the intercept Γ100, but it does affect the slope λ. The friction coefficients M of tailings are similar to those of other nonplastic soils; while mineralogy does not have a significant effect on friction, more angular grains lead to higher friction coefficients.



1988 ◽  
pp. 329-335
Author(s):  
A. Z. Mohamed ◽  
M. M. Mostafa ◽  
M.S. Sakr ◽  
A. A. El-Daly


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