Gold Nuggets Research Articles

(Invited) Are There Still Gold Nuggets on the Sandy Beach? Efforts to Further Reducing the Cost of Li-Ion Batteries through the Discovery of Low-Cost New Cathodes

The cost of lithium-ion batteries (LIBs) has undergone a remarkable reduction, decreasing by approximately an order of magnitude over the past 15 years, from around $1000/kWh to approximately $130/kWh today, following an exponential curve. However, achieving further cost reductions to around $20/kWh within the next 10-15 years is extremely challenging. Despite significant efforts over the past decade or so to decrease the use of expensive Co in LIBs, such as transitioning from NMC111 to NMC811 or NMC9055, semi-expensive Ni is still heavily used, and the manufacturing cost associated with the high-temperature synthesis of layered oxides remains largely unchanged. The manufacturing expense is also a factor in the high cost of LiFePO4, which only comprises abundant elements but requires expensive carbothermal synthesis and carbon coating.There appears to be a long quiet period in the discovery of new intercalation-type cathodes following the successful development of LiCoO2 (1979), LiMn2O4 (1984), LiFePO4 (1997), and the NMC family (1990s). To date, no cathode material for rechargeable LIBs beyond those listed above has been commercialized on a large scale. Here we present the recent discovery of a novel, low-cost intercalation cathode that demonstrates very good performances in an all-solid-state configuration and shows significant potential for commercialization. When paired with a competitive solid electrolyte, this cathode material displays two flat voltage plateaus averaging at 3.65 V, an impressive initial capacity of 159 mAh/g, a high energy density of 580 Wh/kg, and stable cycling. Characterizations via neutron diffraction and X-ray absorption spectroscopy reveal that the Li+ storage mechanism is associated with a topotactic intercalation-deintercalation reaction associated to a Fe2+/Fe3+ redox couple during cycling. Most importantly, this cathode material costs only 2% of LiFePO4 and 1% of LiCoO2, holding tremendous promise for commercial applications, particularly in large-scale energy storage such as grid storage.

Earthquakes May Lace Quartz Veins with Gold

Seismic activity may kick off chemical reactions that seed nuggets of gold.

Arsenopyrite from the Low-sulphidation Sedefche Au-Ag deposit, Eastern Rhodopes: Mineral Association and Gold Potential

The Sedefche Au-Ag deposit is located in the eastern Rhodopes, Bulgaria and is part of the Zvezdel-Pcheloyad ore field. The deposit is of low-sulphidation epithermal type, hosted in Oligocene highly silicificated intermediate volcanic tuffs, which lie above shallow marine sediments of organogenic limestones. The orebody has stratiform shape partly outcroping onto the surface. The ore mineralization is represented by small crystals and fine grained aggregates of sulphides (mainly pyrite, arsenopyrite, marcasite, chalcopyrite, galena, sphalerite) and associated sulphosalts (tetrahedrite, pyrargyrite, freibergite, and miargyrite) within matrix of quartz, formed in several stages of deposition. Gold in the deposit is detected in significant amounts in bulk ore samples, while native gold (a single < 1 μm gold nugget) and gold-bearing phases were sporadically discovered. The form of gold presence in the deposit is nevertheless debatable. Using combined SEM-EDS, EPMA and LA-ICP-MS approach, the highest concentrations of gold have been established in the arsenopyrite – the gold content there is up to hundredfold higher than in other ore minerals being potential concentrators of gold such as pyrite, marcasite and chalcopyrite. The presence of gold in arsenopyrite predominantly as nanoparticles, irregularly disseminated in the crystals as clusters of inclusions is suggested.

Gold nuggets from earthquakes

Gold nuggets from earthquakes

Gold nugget formation from earthquake-induced piezoelectricity in quartz

Gold nugget formation from earthquake-induced piezoelectricity in quartz

Gold nugget formation from piezoelectric quartz

Gold nugget formation from piezoelectric quartz

Gold Rush as it Happens in Minas Gerais, Brazil: Geological Reconnaissance and Origin of Gold Nuggets

Gold Rush as it Happens in Minas Gerais, Brazil: Geological Reconnaissance and Origin of Gold Nuggets

Bismuth–tellurium (Bi–Te) oxide compositionally analogous to smirnite (Bi2TeO5) from an alluvial goethite–gold aggregate: First occurrence in South America and its significance

Smirnite is the natural equivalent of Bi2TeO5, a compound that has piezoelectrical and nonlinear optical properties. The mineral has rarely been described worldwide. Here, we describe the finding of a Bi–Te oxide, compositionally similar to the mineral smirnite, from an alluvial gold nugget. The mineral occurs within a goethite pseudomorph after arsenopyrite, forming an aggregate with the nugget gold. Electron-microprobe analyses gave an empirical stoichiometry of (Bi1.6,Fe0.2)1.8Te1.1O5, on the basis of five atoms of oxygen. The occurrence of smirnite in the municipality of Ouro Preto, Minas Gerais, Brazil, is noteworthy because the mineral: (i) is described in South America for the first time; (ii) represents a provenance indicator, connecting the gold nugget to auriferous quartz lodes with primary Bi–Te minerals in the Mariana anticline; (iii) indicates that Bi and Te were retained by goethite formation during oxidative weathering of gold deposits; (iv) has the critical metals Bi and Te as essential components, which should be considered in the economic evaluation of gold prospects as strategically important byproducts, in addition to the potential use of Bi and Te in the weathering zone as pathfinder elements to gold mineralisation at depth.

Widely Targeted Metabolomic Analysis Provides New Insights into the Effect of Rootstocks on Citrus Fruit Quality.

The use of different rootstocks has a significant effect on the content of flavor components and overall fruit quality. However, little information is available about the metabolic basis of the nutritional value of citrus plants. In this study, UPLC-MS/MS (ultra-performance liquid chromatography-tandem mass spectrometry) was performed to analyze the metabolites of three late-maturing hybrid mandarin varieties ('Gold Nugget', 'Tango' and 'Orah') grafted on four rootstocks ('Trifoliate orange', 'Carrizo citrange', 'Red tangerine' and 'Ziyang Xiangcheng'). A total of 1006 metabolites were identified through OPLS-DA (Orthogonal Partial Least Squares-Discriminant Analysis) analysis. KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis revealed the most critical pathways among the different pathways associated with genes grafted on the four rootstocks that were differentially activated, including tryptophan metabolism and sphingolipid metabolism in 'Gold Nugget'; tryptophan metabolism, phenylpropanoid biosynthesis and sphingolipid metabolism in 'Tango'; and pantothenate and CoA biosynthesis- and photosynthesis-related biosynthesis in 'Orah'. A considerable difference between the different rootstocks was also observed in the accumulation of lipids, phenolic acids and flavonoids; further analysis revealed that the rootstocks regulated specific metabolites, including deacetylnomylinic acid, sudachinoid A, amoenin evodol, rutaevin, cyclo (phenylalanine-glutamic acid), cyclo (proline-phenylalanine), 2-hydroxyisocaproic acid, and 2-hydroxy-3-phenylpropanoic acid. The results of this study provide a useful foundation for further investigation of rootstock selection for late-maturation hybrid mandarin varieties.

Gold Recovery from E-Waste by Food-Waste Amyloid Aerogels.

Demand for gold recovery from e-waste grows steadily due to its pervasive use in the most diverse technical applications. Current methods of gold recovery are resource-intensive, necessitating the development of more efficient extraction materials. This study explores protein amyloid nanofibrils (AF) derived from whey, a dairy industry side-stream, as a novel adsorbent for gold recovery from e-waste. To do so, AF aerogels are prepared and assessed against gold adsorption capacity and selectivity over other metals present in waste electrical and electronic equipment (e-waste). The results demonstrate that AF aerogel has a remarkable gold adsorption capacity (166.7mg g-1) and selectivity, making it efficient and an adsorbent for gold recovery. Moreover, AF aerogels are efficient templates to convert gold ions into single crystalline flakes due to Au growth along the (111) plane. When used as templates to recover gold from e-waste solutions obtained by dissolving computer motherboards in suitable solvents, the process yields high-purity gold nuggets, constituted by ≈90.8wt% gold (21-22 carats), with trace amounts of other metals. Life cycle assessment and techno-economic analysis of the process finally consolidate the potential of protein nanofibril aerogels from food side-streams as an environmentally friendly and economically viable approach for gold recovery from e-waste.

Searching with filters in Pubmed. Gathering the gold nuggets.

Una vez obtenidos los resultados de la búsqueda, esta puede refinarse y acotarse aún más con el uso de los filtros de Pubmed.

Konsep Fitnah Dalam Al Qur'an Surah Al Baqarah Ayat 191 dan 217

In general society, the word slander is not a new language. However, the interpretation of the word slander that has existed among the public is often limited to what is meant by accusing it with bad allegations and then following it with evidence in the form of fragments of verses from the QS. Al-Baqarah verse 191 or 217 so it may not lead to the intended purpose of these two verses. The author uses data sourced from journals, commentary books and several literature related to research. Because it focuses on both classical and modern literature, this research is qualitative or library research (literature research) by utilizing comparative methods (muqarran) to compare the interpretations of the two. After conducting research, it can be seen that the comparison of the words slander according to Az-Zamakhsyari and Fakhr ad-Din ar-Razi is concluded with 5 meanings, slander means gold nuggets that are placed on fire to obtain the purity of the gold which then leads to severe trials or are called al-mihnah and al-bala', slander is an eternal punishment that binds a person because disbelief, the prohibition of entering the Grand Mosque and the apostasy of non-believers. The similarities include both methods, namely the tahlili method with the bi al-ra'yi interpretation style and interpreting slander with al-ikhraj. Meanwhile, the differences include the background of Az-Zamakhsyari's writing of al-syirku which is side by side with the interpretation of the root word "al-kufru" belonging to al-Razi.

A comparative analysis between 'Boroca' and 'Buckskin bag' on the lexical effervescence regarding the establishment of gold mines in Brazil and in the USA

This paper addresses the significant influence of economic activities, such as “Gold Rush" or "Gold Fever”, in the United States, and the intense human movement caused by the discovery of "Serra Pelada”, in Brazil, on the language related to the economic context of the affected regions. "Newspaper Corpus from the Library of Congress" was used as a reference for the English term and the archive from Hemeroteca of the National Library was adopted for the Brazilian one. A comparative analysis was conducted between the words "Boroca" (Brazil) and "Buckskin bag" (USA), which refer to a type of bag used by the "garimpeiro" (Brazilian term) and "miner" (American term) to store and transport small gold nuggets. According to the results, gold extraction as an economic activity influences the media propagation of the terms "boroca" and "buckskin bag," revealing similar linguistic behaviors despite the temporal, geographical, and linguistic separation and highlighting the influence of economic activity on the language of society in the 19th and 20th centuries.

The Effects of Cupriavidus Metallidurians on Plant Growth and Development in Areas with Heavy Metal Runoff

This project measures the effects of C. metallidurians on agricultural plant growth in environments with heavy metal runoff. Heavy metals have been known to negatively impact the environment specifically in the form of runoff. Heavy metals usually accumulate plant roots and inhibit nutrient and water transportation within plants. lIn this project, heavy metals being tested include Zinc, which prevents nutrients from being transported to the leaves; Nickel, which inhibits transpiration and photosynthesis and impairs metabolism; and Copper, which can cause protein denaturation and corrupt soil viability. C. metallidurians are a type of bacteria known to have heavy metal resistant plasmids and plasmid determinants specifically directed towards a different heavy metal each, with the cnr being resistant to copper and nickel, chr being resistant to copper and zinc, and cop being resistant to specifically copper. C. metallidurans have previously been known to detoxify high concentrations of copper and gold. They more famously have been known to pump out gold nuggets from exposure to copper metals. Since the effects of other heavy metals on C. metallidurans are not as well studied, this project aims to study the effects of those other heavy metals such as Zinc, Nickel, and Copper and apply this interaction to a real-life scenario of agriculture to see if this bacteria may be able to minimize the damage of Heavy Metal Runoff pollution.

THE RUSH STARTED HERE, PART III: ‘THE STREETS ARE PAVED WITH GOLD’—SPECULATION, GREED, AND DISAPPOINTMENT, 1849–2010

ABSTRACT Profitable gold mining began in the United States with the accidental discovery in 1799 of a seventeen-pound gold nugget in Cabarrus County, North Carolina. North Carolina’s gold production peaked between the 1830s and 1840s as hundreds of mines contributed hundreds of thousands of dollars a year to the national economy, necessitating the 1837 construction of a federal Branch Mint in Charlotte to process Piedmont gold. Gold mining suffered a major decline in North Carolina after the discovery of the richer and more extensive gold deposits in California in 1848. However, the North Carolina gold miners who did not join the western rush continued to work the shafts of the Piedmont using increasingly sophisticated European and South American technology, as well as new innovations such as hydraulic mining techniques from California, until the advent of the Civil War. From the end of Reconstruction (1877) to 1920, gold mining in North Carolina was sporadic and often funded by outside investors or used as a ruse in gold and stock scams. Copper mining, with gold and silver as secondary products, using increasingly complex technology and associated environmental issues, drove most of the mining fervor during this period. Following the Great Depression of the 1930s, gold production slowly increased until the Second World War, but never became a major industry as they were out-competed by the more profitable gold fields in the western United States, Alaska, Canada, Australia, and South Africa. From the 1970s to today, dependent upon the price of gold in the market and the requirements of environmental regulation, prior mining districts in North (and South) Carolina have continued to be examined, explored and cautiously mined using cyanide heap leach techniques. Although few in number, these limited lease mining projects have extracted over two million troy ounces of gold and nearly a million troy ounces of silver by 2010. Future extraction by the ongoing Haile Mine (South Carolina) project will increase this amount substantially in the next decade. Nevertheless, Cabarrus County continues to hold the world’s record for producing the greatest number of large (a pound or more) gold nuggets and was the epicenter of North America’s first gold rush.

Biological Activity of Pumpkin Byproducts: Antimicrobial and Antioxidant Properties

Pumpkin fruits are widely appreciated and consumed worldwide. In addition to their balanced nutritional profile, pumpkin species also present valuable bioactive compounds that confer biological and pharmacological properties to them. However, the seeds, peels, and fibrous strands resulting from pumpkin processing are still poorly explored by the food industry. The current study used those fruit components from the genotypes of pumpkin that are economically significant in Portugal and Algeria to produce bioactive extracts. In order to support their usage as preservatives, their phenolic content (HPLC-DAD-ESI/MS) and antioxidant (OxHLIA and TBARS) and antimicrobial properties (against eight bacterial and two fungal strains) were assessed. In terms of phenolic profile, the peel of the Portuguese 'Common Pumpkin' showed the most diversified profile and also the highest concentration of total phenolic compounds, with considerable concentrations of (-)-epicatechin. Regarding the antioxidant capacity, the seeds of 'Butternut Squash' from both countries stood out, while the fibrous strands of Portuguese 'Butternut Squash' and the seeds of Algerian 'Gold Nugget Pumpkin' revealed the strongest antimicrobial activity. The bioactive compounds identified in the pumpkin byproducts may validate their enormous potential as a source of bio-based preservatives that may enhance consumers' health and promote a circular economy.

Producing gold nugget simulants using copper alloys

Today the imitations of gold nuggets are highly promising materials in conceptual jewelry design. The manufacturing technology of these materials is based on melted brass casting in a cooling liquid. The purpose of this research is to identify the most favorable technological processes to obtaining high-quality simulants of gold nuggets. The article presents the results of the experimental studies of CW508L brass. The most favorable technological parameters have been identified. They include the melt temperature up to 970±5 °C and use of water with the temperature not higher than 20–25 °C as a cooling liquid. Adherence to the specifications allows to obtain the casts, which superficially resemble natural gold nuggets found in alluvial gold deposits. The casts’ intricate shape and uneven relief providing this resemblance are due to the specific crystallization conditions of brass that differ from the crystallization conditions under conventional casting. The research involved the analysis of the chemical composition of the alloy samples before tests and the samples obtained after casting. After processing the alloy has featured an insignificant decrease in the zinc percentage, and an increase in the impurity content (silica, sulfur, iron, and chrome). The metallographic analysis of the initial sample of CW508L brass has shown a single-phase microstructure that is a solid solution of zinc substitution by copper. The similar study of the casts obtained in the experiment has shown the presence of a β-phase in their structure (along with an α solid solution) that is a CuZn-based solid solution having a positive effect on brass mechanical properties. This microstructure is typical of the alloys undergone accelerated cooling that qualitatively changes the process of melt converting into a solid substance.

Dynamics of artisanal gold mining in Gashaka local government area of Taraba State, Nigeria

Despite the fact that gold has been mined in Gashaka, Taraba State for over a century and has continued to present day in the area, not much is known about this activity and its associated environmental impact in the state. This study therefore, examines the dynamics of artisanal small scale gold mining activities in Gashaka Local Government Area of Taraba State, Nigeria. The study adopted survey research design approach which involves the use of direct fieldwork observation and interview of key informants. The findings of the study reveals that alluvial gold is mined along the streams and farmlands on the floodplains in the area. The gold exists as alluvial gold dust and nugget gold. The artisanal gold mining activity is carried out with rudimentary materials such as pickaxes, diggers, shovels, spades, pans and water pumps. Some of the local mining communities are Gayam, Jamtari, Karamti, Serti, Goje, Bodel, Mayo Jim, Bashishir, Kurr and Garbabi. The 3 major methods employed by artisanal gold miners in the study area include panning method, use of locally constructed devices and picking of gold nuggets or crystals from dug pit on the floodplain. The artisanal gold miners use sulphuric acid and white mercury in purifying the collected gold. The miners do not use any protective gears such as face masks, rubber gloves, leather boots or head coverings in the mining process. All golds collected from the mining activities are sold in the town (Serti/Baruwa). There is a ready market with both local buyers residing in the town and distant buyers coming from different parts of the country. Artisanal gold mining is an important livelihood activity in the study area despite the fact that many of them are carried out illegally. Based on the findings, the study recommended the establishment of a goldsmith industry, improvement in security in the local communities and organizing the artisanal gold miners into cooperative organizations.

Searching gold origin through litho-structural analysis and morphological characterization of alluvial gold nuggets in the Guiwa-Yangamo area (Batouri goldfield, Eastern Cameroon)

Searching gold origin through litho-structural analysis and morphological characterization of alluvial gold nuggets in the Guiwa-Yangamo area (Batouri goldfield, Eastern Cameroon)

Unraveling factors affecting consumers' liking of novel Uruguayan mandarins

Mandarin cultivars show a great diversity on fruit-quality and sensory characteristics, together with an extended harvest season. Citrus breeding is focused on exploiting season niches for higher prices as well as nutritional and sensory aspects, among others. In this context, the sensory characterization of new hybrids and the identification of key characteristics of consumers´ liking provide valuable information towards breeding efforts and marketing strategies. Previous works showed that sensory characteristics, and specially flavor, play a key role in consumer acceptance of mandarins. Two studies were carried out during mandarin harvest season (mid and late) applying “check all that apply” (CATA) questions with at least 100 consumers. Overall liking scores of the most liked hybrids and cultivars ranged between 6.5 to 7.7 in the 9-point hedonic scale, evidencing a positive hedonic reaction. Local hybrids showed similar or higher values than the reference cultivars Tango, Gold Nugget, Murcott and Ortanique. Results showed that orange color, regular shape, smoothness, sweetness, juiciness, intense and typical flavor are the key drivers of consumer's liking of mandarins, and that external appearance is not a good predictor of mandarin tasting experience. Hybrids F3P8, F5P8 and F2P3 were described using terms related to positive sensory characteristics and received liking scores similar or higher to reference cultivars such as Tango, stressing the importance of sensory and consumer science as an integral part of breeding strategies.