Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
Topic Review
List of Minerals Approved by IMA (T)
This list includes those recognised minerals beginning with the letter T. The International Mineralogical Association is the international group that recognises new minerals and new mineral names, however minerals discovered before 1959 did not go through the official naming procedure, although some minerals published previously have been either confirmed or discredited since that date. This list contains a mixture of mineral names that have been approved since 1959 and those mineral names believed to still refer to valid mineral species (these are called "grandfathered" species). The data was exported from mindat.org on 29 April 2005; updated up to 'IMA2018'. The minerals are sorted by name, followed by the structural group (rruff.info/ima and ima-cnmnc by mineralienatlas.de, mainly) or chemical class (mindat.org and basics), the year of publication (if it's before of an IMA approval procedure), the IMA approval and the Nickel–Strunz code.
  • 1.7K
  • 09 Oct 2022
Topic Review
"Zorbas" on Southeastern Sicily
Over the last few years, several authors have presented contrasting models to describe the response of boulders to extreme waves, but the absence of direct observation of movements has hindered the evaluation of these models. The recent development of online video-sharing platforms in coastal settings has provided the opportunity to monitor the evolution of rocky coastlines during storm events. In September 2018, a surveillance camera of the Marine Protected Area of Plemmirio recorded the movement of several boulders along the coast of Maddalena Peninsula (Siracusa, Southeastern Sicily) during the landfall of the Mediterranean tropical-like cyclone (Medicane) Zorbas. Unmanned autonomous vehicle (UAV) photogrammetric and terrestrial laser scanner (TLS) surveys were performed to reconstruct immersive virtual scenarios to geometrically analyze the boulder displacements recorded in the video. Analyses highlighted that the displacements occurred when the boulders were submerged as a result of the impact of multiple small waves rather than due to a single large wave. Comparison between flow velocities obtained by videos and calculated through relationships showed a strong overestimation of the models, suggesting that values of flow density and lift coefficient used in literature are underestimated.
  • 1.7K
  • 25 Aug 2021
Topic Review
Expert System for Earthquake Prediction
Earthquake is one of the most hazardous natural calamity. Many algorithms have been proposed for earthquake prediction using expert systems (ES). We aim to identify and compare methods, models, frameworks, and tools used to forecast earthquakes using different parameters. The analysis shows that most of the proposed models have attempted long term predictions about time, intensity, and location of future earthquakes. An investigation on different variants of rule-based, fuzzy, and machine learning based expert systems for earthquake prediction has been presented. Moreover, the discussion covers regional and global seismic data sets used, tools employed, to predict earth quake for different geographical regions. Bibliometric and meta-information based analysis has been performed by classifying the articles according to research type, empirical type, approach, target area, and system specific parameters.
  • 1.6K
  • 03 Feb 2021
Topic Review
Marine Nepheloid Layer
Marine nepheloid layer is a turbid layer containing significantly more suspended particles than the adjacent layers in oceans. The suspended particles may collide and form large falling particle aggregates known as marine snow. Although the nepheloid layer continually changes with time and space, it shows certain temporal and spatial stability. A marine nepheloid layer could last a few days to years, with a thickness ranging from meters to kilometers.
  • 1.5K
  • 16 Mar 2022
Topic Review
Saline Lakes
Saltwater lakes around the world are drying at a rapid rate. These lakes are present in arid and semi-arid regions where evaporation exceeds precipitation. The Aral Sea and Lake Urmia are examples for such rapidly drying lakes. These two lakes have lost up to 90% of their former area in the past 50 years.  
  • 1.5K
  • 28 Oct 2020
Topic Review
Water Footprint
The water footprint (WF) is a widely recognised and comprehensive indicator of both the direct and indirect appropriation of freshwater. It has been utilised for diverse functions, including as a key indicator of the planetary boundaries and United Nations Sustainable Development Goals. (draft for definition)
  • 1.4K
  • 03 Feb 2022
Topic Review
Agate
Agate ‒ a spectacular form of SiO2 and a famous gemstone ‒ is commonly characterized as banded chalcedony. In detail, chalcedony layers in agates can be intergrown or intercalated with macro-crystalline quartz, quartzine, opal-C, opal-CT, cristobalite and/or moganite. In addition, agates often contain considerable amounts of mineral inclusions and water as both interstitial molecular H2O and silanol groups.
  • 1.4K
  • 16 Apr 2021
Topic Review
Cenozoic Basins-evolution Eastern-External Betic Zone
Four main unconformities (1-4) were recognized in the sedimentary record of the Cenozoic basins of the eastern External Betic Zone. More in detail, they are located at different stratigraphic levels as follows: (1) Cretaceous-Paleogene boundary even if this unconformity was also recorded at the early Paleocene (Murcia sector) and early Eocene (Alicante sector); (2) Eocene-Oligocene boundary and quite synchronous in the whole considered area; (3) early Burdigalian, and quite synchronous (recognized in the Murcia sector); (4) middle Tortonian (recognized in Murcia and Alicante sectors). These unconformities correspond to stratigraphic gaps of different temporal extensions with different meanings, which allowed recognizing minor sedimentary cycles in the Paleocene-Miocene time span. The Cenozoic marine sedimentation started over the oldest unconformity (i.e. the principal one), above the Mesozoic marine deposits. Paleocene-Eocene sedimentation shows numerous tectofacies (such as: turbidites, slumps, olistostromes, mega-olistostromes and pillow-beds) interpreted as related to an early, blind and deep-seated tectonic activity, acting in the more internal subdomains of the External Betic Zone as a result of the geodynamic processes related to the evolution of the westernmost branch of the Tethys. The second unconformity resulted from a Oligocene to Aquitanian sedimentary evolution in the Murcia Sector from marine realms to continental environments. This last time interval is characterized as the previous one by a gentle tectonic activity. On the other hand, the Miocene sedimentation was totally controlled by the development of superficial thrusts and/or bend zones of strike-slip faults both related to the regional geodynamic evolutionary framework linked to the Mediterranean opening. These bends of strike-slip faults created subsidence areas (pull-apart basin-type) and affected the sedimentation lying above the third unconformity. By contrast, the subsidence areas were bounded by structural highs affected by thrusts and folds. After the third unconformity, the Burdigalian-Serravallian sedimentation occurred mainly in shallow- to deep-water marine environments (Tap Fm). During the late Miocene, after the fourth unconformity, the activation of the bend zones of strike-slip faults caused a shallow marine environment sedimentation in the Murcia sector and a continental (lacustrine and fluvial) deposition in the Alicante sector represented, the latter resulting in alluvial fan deposits. Furthermore, the location of these fans changed over time according to the activation of faults responsible for the tectonic rising of Triassic salt deposits, which fed the fan themselves.
  • 1.4K
  • 10 Oct 2020
Topic Review
Jáchymov
Jáchymov (Czech pronunciation: [ˈjaːxɪmof]); German: Sankt Joachimsthal or Joachimsthal) is a spa town in Karlovy Vary District in the Karlovy Vary Region of the Czech Republic. It has about 2,300 inhabitants. The historical core of the town from the 16th century is well preserved and protected by law as urban monument zone. It is a comprehensive set of Gothic–Renaissance patrician houses. Jáchymov has a long mining tradition, thanks to which it used to be the second most populous town in the Kingdom of Bohemia in 1534. At first silver was mined here. The silver Joachimsthaler coins minted here since the 16th century gave their name to the Thaler and the dollar. After the Wieliczka Salt Mine ceased industrial exploitation in 2007, the Svornost mine (1525) became the oldest mine still in use in Europe. It is also the first and for a long time the only mine in the world, where radium was mined. The mining cultural landscape of Jáchymov is a UNESCO World Heritage Site as a part of the Ore Mountain Mining Region.
  • 1.3K
  • 04 Nov 2022
Topic Review
Impact of High-Temperature Treatment on Granite
Temperature changes have significant effects on rock properties. The changes in properties vary for different rocks with different temperature ranges. Granite is an igneous type of rock that is common in India and is frequently used for construction and domestic purposes. Granite is mainly composed of quartz and feldspar and shows a considerable response to temperature changes. The heating effects of granite on its physical and mechanical properties become increasingly pronounced with increasing pick temperatures. 
  • 1.2K
  • 29 Nov 2022
Topic Review
Zagros Fold and Thrust Belt
The Zagros fold and thrust belt (Zagros FTB) is an approximately 1,800-kilometre (1,100 mi) long zone of deformed crustal rocks, formed in the foreland of the collision between the Arabian Plate and the Eurasian Plate. It is host to one of the world's largest petroleum provinces, containing about 49% of the established hydrocarbon reserves in fold and thrust belts and about 7% of all reserves globally.
  • 1.2K
  • 08 Nov 2022
Topic Review
Antimony as a Critical Raw Material
Antimony is widely acknowledged as a critical raw material of worldwide significance, based on its recognition by many countries. According to current projections, there is an anticipated increase in the demand for antimony in the forthcoming years. An issue of significant concern within the supply chain, which poses a substantial obstacle to sustainable development, is the global unequal allocation of abundant antimony resources. Most nations exhibited a high degree of dependence on a few countries for their net imports of antimony, resulting in a notable disruption and raising concerns regarding the supply chain. 
  • 1.1K
  • 23 Feb 2024
Topic Review
Debris Flow Hazard
Global climate change has increased severe torrential hazards, particularly debris flows in mountainous regions. After floods and earthquakes, debris flows are the most devastating natural hazard in the world. The effects of debris flow on human life and built environments necessitate reconsidering current infrastructure planning, engineering, and risk management practices. Hence, the vulnerability of elements at risk is critical for effective risk reduction systems.
  • 1.1K
  • 27 Dec 2022
Topic Review
DSGSDs on Mars
Deep-Seated Gravitational Slope Deformations (DSGSDs) are a set of slow and complex gravity-driven deformational processes, involving entire slopes (or large portions of them) over long time intervals. These phenomena have been identified on Mars since the early 2000s, and several detailed studies were conducted on them.
  • 1.1K
  • 29 Apr 2021
Topic Review
Iron Silicides
Iron silicide minerals (Fe-Si group) are found in terrestrial and solar system samples. These minerals tend to be more common in extraterrestrial rocks such as meteorites, and their existence in terrestrial rocks is limited due to a requirement of extremely reducing conditions to promote their formation. Such extremely reducing conditions can be found in fulgurites, which are glasses formed as cloud-to-ground lightning heats and fuses sand, soil, or rock. 
  • 1.1K
  • 19 Apr 2022
Topic Review
Fissure Ridges
Fissure ridges consist of elongated travertine masses with an apical fissure that follows the long axis of the body. Two symmetrical or asymmetrical walls made up of bedded travertine are typically dipping away from the central fissure. The internal part of the fissure is often cut by a network of sealed fractures, almost parallel to the long axis of the ridge, normally filled by banded Ca-carbonate (i.e., calcite and/or aragonite), almost parallel to the vein-walls (the so called “banded travertine” in). These veins developed within the fault zone and represent conduits along which geothermal fluids move towards the surface. Therefore, their analysis, in terms of geometry, age (using U/Th, U/Pb, and 14C geochronology), and geochemical properties, provides information about the structural features and timing of the fault system, and on the fluid path from depth to surface. Furthermore, travertine deposited in a fissure ridge is characterized by distinct petrographic and geochemical features preserving information on the parent fluids and ancient depositional conditions. The shape of the fissure ridge body depends on the flow rate, carbonate precipitation rate, and surface topography upon which deposition took place.
  • 1.1K
  • 13 Jul 2021
Topic Review
Amin Beiranvand Pour
My scholarly interests range widely, from mineral exploration to environmental issues such as geo-hazard, structural mapping, geothermal and geomorphic and coastal geology investigations. Subsequently, I have conducted several research projects for geological mapping, disaster management and environmental modeling using a variety of satellite remote sensing data such as the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Landsat Enhanced Thematic Mapper+ (ETM+), Landsat-8, Advanced Land Imager (ALI), Hyperion and Phased Array type L-band Synthetic Aperture Radar (PALSAR) satellite data in arid and semi-arid terrains, Antarctic, Arctic and tropical environments. 
  • 1.1K
  • 10 Nov 2020
Topic Review
Applications of DAS in Linear Infrastructure Monitoring
Linear infrastructures, such as railways, tunnels, and pipelines, play essential roles in economic and social development worldwide. Distributed acoustic sensing (DAS) is an emerging sensing technology that has rapidly developed in recent years. Due to its unique advantages in long-distance, high-density, and real-time monitoring, DAS arrays have shown broad application prospects in many fields, such as oil and gas exploration, seismic observation, and subsurface imaging. In the field of linear infrastructure monitoring, DAS has gradually attracted the attention of researchers and practitioners. 
  • 1.1K
  • 01 Dec 2022
Topic Review
Crystal Mush
A crystal mush is a magmatic body which contains a significant amount of crystals (up to 50% of the volume) suspended in the liquid phase (melt). As the crystal fraction makes up less than half of the volume, there is no rigid large-scale three-dimensional network as in solids. As such, their rheological behavior mirrors that of absolute liquids. Within a single crystal mush, there is grading to a higher solid fraction towards the margins of the pluton while the liquid fraction increases towards the uppermost portions, forming a liquid lens at the top. Furthermore, depending on depth of placement crystal mushes are likely to contain a larger portion of crystals at greater depth in the crust than at shallower depth, as melting occurs from the adiabatic decompression of the magma as it rises, this is particularly the case for mid-oceanic ridges. Seismic investigation offers strong evidence for the existence of crystal mushes rather than fully liquid magmatic bodies. Crystal mushes can have a wide range of chemical and mineralogical compositions, from mafic (SiO2-poor, MgO-rich) to felsic (SiO2-rich, MgO-poor).
  • 1.1K
  • 01 Dec 2022
Topic Review
Pyrolysis of Technogenic-Redeposited Coal-Bearing Rocks
Hydrocarbon products formed under high-temperature and low-temperature pyrolysis of coal-bearing rocks were studied by using a chromatography-mass spectrometer GCMS-QP2010NC Plus (made by Shimadzu Company). The average temperature of low-temperature natural pyrolysis does not exceed 120°C, and its average speed is approximately 2 m/year. In this case, three pyrolysis zones gradually built metamorphic rock mass (from bottom to top) are clearly established: heating (focal) activated and enriched. The average temperature of high-temperature pyrolysis reaches 850°C, and its average speed is approximately 20 m/year. Unlike low-temperature pyrolysis, high-temperature pyrolysis is accompanied by the presence of two major zones (from bottom to top): pyrogenic (focal) and enriched (coke). The chemical composition of the enriched pyrolysis zone was studied in detail. It has been established that hydrocarbon compounds in samples of the pyrolysis zone are presented by six classes: asphaltic-resinous substances; polycyclic aromatic hydrocarbons, heterocyclic compounds, organic sulphur compounds; pyrolytic hydrocarbon and heavy hydrocarbon residue. Quantitative content of hydrocarbon compounds in the analyzed samples varies from 0.35% to 41.88%.   Based on the materials of fieldwork, we created a video film that can be seen on the website https://youtu.be/Tqs6YiKfDdE
  • 1.0K
  • 29 Oct 2020
  • Page
  • of
  • 6
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Fungi
Encyclopedia of Digital Society, Industry 5.0 and Smart City
ScholarVision Creations
Feedback