Search results for "Mining engineering"
showing 10 items of 60 documents
The Grain Boundary Wetting Phenomena in the Ti-Containing High-Entropy Alloys: A Review
2021
In this review, the phenomenon of grain boundary (GB) wetting by melt is analyzed for multicomponent alloys without principal components (also called high-entropy alloys or HEAs) containing titanium. GB wetting can be complete or partial. In the former case, the liquid phase forms the continuous layers between solid grains and completely separates them. In the latter case of partial GB wetting, the melt forms the chain of droplets in GBs, with certain non-zero contact angles. The GB wetting phenomenon can be observed in HEAs produced by all solidification-based technologies. GB leads to the appearance of novel GB tie lines Twmin and Twmax in the multicomponent HEA phase diagrams. The so-cal…
The geology of Cuba: A brief overview and synthesis
2016
Cuba is the largest island in the Greater Antilles, and its geology records three important episodes: (1) the Jurassic breakup of North and South America (Pangea) and associated passive margin and oceanic sedimentary and magmatic evolution; (2) the sedimentary, magmatic, and metamorphic evolution of an intra-oceanic Cretaceous-Paleogene ophiolite-arc complex; and (3) the Paleogene 'soft collision' and transfer of the NW Caribbean plate (and Cuba) to the North American plate. Thick sequences of Jurassic-Cretaceous strata (conglomerates, sandstones, limestones, dolostones, shales) and interlayered basaltic rocks characterize passive margin sequences preserved in the Guaniguanico terrane (wes…
Analysis of Cipollino Verde marble wall decoration in Ephesos, Turkey, using geological reconstruction
2021
Abstract Slabs of Cipollino Verde, composed of layered and folded marble from Euboea in Greece, decorated the hall of a Roman town house in Ephesos, Turkey in the second century AD. After excavation, the fragmented slabs were restored. Preservation of the dowels in the walls from which the slabs were originally suspended allowed reconstruction of the order in which they had been placed on the walls. The pattern of folded layering in the slabs in turn allowed 3D structural geological reconstruction of the folds, and reconstruction of the arrangement of slabs in the marble block, from where they were serially sectioned, using a slab saw. Investigation of geological fold alignment in the block…
Ceramic raw materials: how to recognize them and locate the supply basins—mineralogy, petrography
2020
This tutorial paper is focused on the mineralogical-petrographic characterization of clayey raw materials with the purpose of sourcing supply basins and answering questions about the provenance of the corresponding archaeological ceramic artefacts. The first part gives general indications of how to profitably study archaeological ceramic thin sections through the polarizing microscope. Brief notes are provided on the theoretical basis of optical microscopy. A scheme is then provided for the petrographic description of ceramic samples, concerning the textural and compositional characteristics of aplastic inclusions and groundmass. Suggestions are also given for identifying any minero-petrogr…
Study of phase composition, photocatalytic activity, and photoluminescence of TiO2 with Eu additive produced by the extraction-pyrolytic method
2021
The Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2. The work was also partially supported by the LZP grant 2020/2-0074. R. Burve has been supported by the project “Synthesis of nanostructured materials based on titanium dioxide and tin dioxide and investigation of their physicochemical properties” Nr. MP-2019/7, for strengthening scientific personnel capacity 2019/2020 at the Riga Technical University. Authors are grateful to Dr. K. Šmits for the microscopic measurements and SEM images.
Using mechanical experiments to study ground stone tool use: Exploring the formation of percussive and grinding wear traces on limestone tools
2021
Ground Stone Tools (GST) have been identified in several Levantine archaeological sites dating to the Middle Paleolithic. These tools, frequently made of limestone, are often interpreted based on their morphology and damage as having been used for knapping flint, and sometimes for breaking animal bones or processing vegetal materials as well. However, the lack of experimental referential collections on limestone is a major obstacle for the identification of diagnostic traces on these types of tools and raw material. In this sense, the understanding of the specific function of these GST and the association between tool types and activity often remains unknown or merely speculative. Recent di…
Study on Experimental Determination of the Elasticity Modulus of Casted Basalt
2020
Basalt is a material available in big quantities in nature. It has a low price and can be used in various domains. It can be relatively easily extracted from natural deposits and processed by means of melting. Melted and recrystallized basalt has demonstrated promising behavior with regards of its use in manufacturing, as reported in the literature. This paper presents the results of an experimental study on the determination of the modulus of elasticity of molten and recrystallized basalt by the method of resistive electrical tensometry and to validate the result and by simulation using finite elements method. Testing methodology, experimental test, data records, data processing and result…
Cadmium Recovery from Spent Ni-Cd Batteries: A Brief Review
2021
The significant increase in the demand for efficient electric energy storage during the past decade has promoted an increase in the production and use of Cd-containing batteries. On the one hand, the amount of toxic Cd-containing used batteries is growing, while on the other hand, Cd is on a list of critical raw materials (for Europe). Both of these factors call for the development of effective technology for Cd recovery from spent batteries. The present paper is aimed at providing a short review of the recent progress in Cd recovery from spent batteries. Statistical data from the past decade on the source of Cd, its global production, and Ni-Cd battery recycling are given in the introducti…
Characterisation of clayey raw materials for ceramic manufacture in ancient Sicily
2011
Abstract It is well known that mineralogical, petrographic and chemical analyses can successfully support provenance studies of archaeological ceramics. The characterisation of a ceramic paste, the assessment of its technology of production and its provenance assignment related to a specific production centre or to a geographical and/or compositional space, are all tasks that can be performed even more accurately if the clayey raw materials used in pottery production are also studied. For that reason the identification of the clay deposits exploited in a given ceramic workshop often plays a key role in the archaeometric reconstruction of the production cycle where geology, mineralogy, petro…