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Topic Review
Mineral Physics
Mineral physics is the study of mineralogical problems through the application of condensed matter physics and solid-state chemistry.  
  • 1.1K
  • 31 May 2021
Topic Review
Mineral-Supported Photocatalysts
Although they are of significant importance for environmental applications, the industrialization of photocatalytic techniques still faces many difficulties, and the most urgent concern is cost control. Natural minerals possess abundant chemical inertia and cost-efficiency, which is suitable for hybridizing with various effective photocatalysts. The use of natural minerals in photocatalytic systems can not only significantly decrease the pure photocatalyst dosage but can also produce a favorable synergistic effect between photocatalyst and mineral substrate. Owing to their unique structures, large surface area, and negatively charged surface, silicate minerals could enhance the adsorption capacity, reduce particle aggregation, and promote photogenerated electron-hole pair separation for hybrid photocatalysts. Moreover, controlling the morphology and structure properties of these materials could have a great influence on their light-harvesting ability and photocatalytic activity. Composed of silica and alumina or magnesia, some silicate minerals possess unique orderly organized porous or layered structures, which are proper templates to modify the photocatalyst framework. The non-silicate minerals (referred to carbonate and carbon-based minerals, sulfate, and sulfide minerals and other special minerals) can function not only as catalyst supports but also as photocatalysts after special modification due to their unique chemical formula and impurities. The dye-sensitized minerals, as another natural mineral application in photocatalysis, are proved to be superior photocatalysts for hydrogen evolution and wastewater treatment. 
  • 350
  • 16 Aug 2022
Topic Review
Mineralizing Fluids at Porphyry Deposits of Cu−Mo−Au System
The porphyry type of hydrothermal mineral deposits is of paramount economic importance because deposits of this type host much of the world’s reserves of Cu, Mo, and Re, as well as much Re and remarkable reserves of critical elements such as Ag, Pd, Te, Se, Bi, Zn, and Pb. Porphyry deposits are conventionally classified into mineralogical–geochemical types according to their dominant valuable components. The most economically important porphyry-type deposits are those of the Cu (Au), Cu–Mo (Au), Mo, and Au types.
  • 899
  • 05 May 2022
Topic Review
Mineralogy and Geochemistry of Ferromanganese Crusts
Late Pleistocene–Holocene rocks from the western part of Cocos-Nazca Spreading Centre (C-NSC) include ferromanganese crusts that elucidate the geochemistry and mineralogy of a deep-sea geological setting. Geochemical, mineralogical and petrological signatures indicate complex formation influenced by mild hydrothermal processes. These crusts consist mostly of mixed birnessite, todorokite-buserite, and Mn-(Fe) vernadite with traces of diagenetic manganates (asbolane), Fe-oxides and oxyhydroxides or hydrothermally associated and relatively pure Mn-oxyhydroxides (manganite). The average Mn/Fe ratio is 2.7, which suggests predominant mixed hydrogenous-early diagenetic crusts with hydrothermal influences. The mean concentrations of three prospective metals (Ni, Cu and Co) are low: 0.17, 0.08 and 0.025 wt %, respectively. The total content of ΣREY is also low, and ranges from 81 to 741 mg/kg (mean 339 mg/kg).
  • 666
  • 27 May 2022
Topic Review
Minimum Energy Performance Standards in Colombia
The minimum energy performance standards (MEPS) has become a mandatory government document to evaluate the energy efficiency of different equipment and thus limit the minimum energy consumption in domestic, commercial, and industrial applications, guaranteeing end users are able to select more efficient equipment. In order to be compared with the Colombian panorama at the market, technical and political levels, some reference countries and their energy policies were consulted. This allows the establishment of common aspects and differences related to the determination of energy consumption, adjusted volume, and formalization of efficiency ranges, and in the specific case of domestic refrigeration in Colombia.
  • 1.3K
  • 10 Feb 2023
Topic Review
Mining Effects on the Karst
Karst develops on soluble rocks (limestone, dolomite, and evaporite). The infiltrating water with carbonic acid creates cavities (caves), fills them, and flows towards the mountain margin (karst water), where it emerges in springs. The infiltrated water constitutes a three-dimensional system whose surface is the karst water level, which undergoes fluctuation of various degrees and periods due to natural and artificial effects, at another time a one-way rise or subsidence. Since karst rocks drain water, neither a surface water network nor valleys develop (they are only formed at sites where the valley is inherited from the non-karstic cover or when the karst water level is situated at the valley floor). The dissolved material is transported into the karst with the infiltrating waters; therefore, surface karst features are closed. These are karren, dolines, ponors with blind valleys, and poljes. The material transported in the solution precipitates as freshwater limestone.
  • 759
  • 05 Dec 2022
Topic Review
Miragaia Longicollum
Miragaia (named after Miragaia, the parish in Portugal and geologic unit where its remains were found) is a long-necked stegosaurid dinosaur. Its fossils have been found in Upper Jurassic rocks in Portugal (Lourinhã Formation, Sobral Unit) and possibly also Wyoming, United States (Morrison Formation). Miragaia has the longest neck known for any stegosaurian, which included at least seventeen vertebrae.
  • 1.1K
  • 14 Nov 2022
Topic Review
Mismanaged Plastics and Measures for Mitigation
The mismanagement of plastic materials has grown to become a mounting global pollution concern that is closely implicated in unsustainable production and consumption paradigms. The ecological, social, and economic impacts of plastic waste mismanagement are currently transboundary in nature and have necessitated numerous methods of government intervention in order to address and mitigate the globalized and multifaceted dilemmas posed by high rates and volumes of plastic waste generation.
  • 785
  • 25 Jan 2022
Topic Review
Mitigation of Global Warming in Australia
Mitigation of global warming involves taking actions to reduce greenhouse gas emissions and to enhance sinks aimed at reducing the extent of global warming. This is in distinction to adaptation to global warming, which involves taking action to minimize the effects of global warming. Scientific consensus on global warming, together with the precautionary principle and the fear of non-linear climate transitions, is leading to increased effort to develop new technologies and sciences and carefully manage others in an attempt to mitigate global warming. In order to make a significant change, coal from Australia needs to be replaced with alternatives. Carbon capture and storage in Australia has been put forward as a solution for production of clean hydrogen from natural gas. Following the introduction of government mandatory renewable energy targets, more opportunities have opened up for renewable energy technologies such as wind power, photovoltaics, and solar thermal technologies. The deployment of these technologies provides opportunities for mitigating greenhouse gases. A carbon price was introduced on 1 July 2012 by the government of Julia Gillard with the purpose of reducing Australia 's carbon emissions. It requires large businesses (defined as those with annual carbon dioxide equivalent emissions over 25,000 tonnes annually) to pay a price for emissions permits. The tax was scrapped by the Abbott government in July 2014 in what was a widely criticized and highly publicized move.
  • 567
  • 12 Oct 2022
Topic Review
Mobile Local Search
Mobile local search is a technology that lets people search for local things using mobile equipment such as mobile phones, PDAs, and other mobile devices. Mobile local search satisfies the need to offer a mobile subscriber spontaneous access to near-position services and information such as businesses, products, events, restaurant, movie theatre or other local information. Mobile local search is the search and discovery of persons, places, and things within an identifiable space defined by distinct parameters. These parameters are evolving. Today they include social networks, individuals, cities, neighborhoods, landmarks, and actions that are relevant to the searcher's past, current, and future location. These parameters provide structure to vertically deep and horizontally broad data categories that can stand-alone or are combined to comprise searchable directories. Mobile local search is usually based on organized directories accessed through specialized search tools, rather than the web, although mobile local search often provides links to mobile (WAP) web sites. It is also an application of a location-based service.
  • 384
  • 25 Nov 2022
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