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Digital replication of an existing cast gold onlay anatomy to a more esthetic material for a new complete denture is challenging. A technique is presented that uses digital technology to fabricate a new maxillary complete denture with monolithic zirconia onlays that duplicate the anatomy of an existing complete denture with cast gold onlays., (© 2023 The Authors. Journal of Prosthodontics published by Wiley Periodicals LLC on behalf of American College of Prosthodontists.)

Paper‐based analytical devices as a low‐cost and point‐of‐care sensing platform have attracted widespread research interest. However, the device fabrication and signal readout remain a challenge for their real‐world applications. Herein, a technically simple paper‐based sensor is developed by taking advantage of the easily accessible paper and the plasmonic property of gold nanomaterials. The sensing mechanism relies on the iodide‐mediated surface etching of gold nanostars that induces a color change from blue to red of the paper strip. The versatility of the paper substrate in size, shape, and materials allows for the facile immobilization of gold nanostars by a simple immersing method, which is easy to operate and free from specialized skills and equipment. In addition, the readout of the paper strip can be conveniently visualized by the naked eye or through a smartphone. This paper‐based sensor advantages in low cost, light weight, easy handling, and disposability that holds great promise as a point‐of‐care detection platform in resource‐constrained settings. [ABSTRACT FROM AUTHOR]

BACKGROUND: Flexible surface‐enhanced Raman spectroscopy (SERS) substrates such as paper‐based substrates show great potential for rapid detection of residual chemicals on food surfaces. However, controlling the density and distribution of metallic nanoparticles adsorbed on the paper is still challenging. RESULTS: The amount of gold (Au) nanospheres (51 ± 4 nm) attached on the filter paper modified with 3‐aminopropyltriethoxysilane (APTES) was tunable, increasing as the level of APTES (2.5–15.0 g kg−1) applied for paper modification increased. Moreover, the Au nanospheres were relative evenly distributed on the filter paper modified with 2.5–10.0 g kg−1of APTES, which resulted in excellent intra‐ and inter‐reproducibility of SERS signals for pesticides including thiram, diquat dibromide, and paraquat dichloride (relative standard deviation = 2.2–10.1%). The modified paper‐based substrate could be used to detect as low as 0.05–0.2 mg L−1 of pesticides in standard solutions, and as low as 5–20 ng cm−2 of residual pesticides on apple skins with minimum sample pretreatment. CONCLUSION: This paper‐based substrate with tunable feature for the density and distribution of nanoparticles is applicable for rapid SERS detection of residual pesticides in fruits and vegetables. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In this report, gold nanoparticles (GNPS) were synthesized using cell-free extracts of seven different isolates, namely, Pseudomonas aerogenosa CEBP2, Pseudomonas sp. CEBP1, Pseudomonas pseudoalcaligenes CEB1G, Acinetobactor baumani CEBS1, Cuprividus sp. CEB3, Micrococcus luteus CUB12, and Pandoraea sp. CUB2S. The spectroscopic (UV-vis, FTIR, DLS, XRD, EDS) and microscopic (FESEM, TEM) results confirm the reduction of Au 3+ to Au 0 in the presence of biomolecules having reducing as well as self-stabilizing activity. In this green synthesis approach, the average particle size of biosynthesized GNPS might vary (4-60 nm) depending on the bacterial species, pH of the media, incubation time, and temperature. In this study, GSH-modified BSGNPs (Au-GSH) have shown antimicrobial activity with better stability against Gram-positive bacteria. After conjugation of lysozyme with Au-GSH (lyso@Au-GSH), the zone of inhibition was enhanced from 12 to 23 mm (Au-GSH). The TEM study shows the spherical GNP (16.65 ± 2.84) turns into a flower-shaped GNP (22.22 ± 3.12) after conjugation with lysozyme due to the formation of the protein corona. Furthermore, the nanobioconjugate (lyso@Au-GSH) was immobilized with Nafion on a glassy carbon electrode to fabricate a label-free impedance biosensor that is highly sensitive to monitor changes in the transducer surface due to biomolecular interactions. The uniquely designed biosensor could selectively detect Gram-positive bacteria in the linear range of 3.0 × 10 1 -3 × 10 10 cfu mL -1 with RE <5%. The proposed simplest biosensor exhibited good reproducibility (RSD = 3.1%) and excellent correlation (R 2  = 0.999) with the standard plate count method, making it suitable for monitoring Gram-positive bacterial contamination in biofluids, food, and environmental samples., (© 2023 American Institute of Chemical Engineers.)

Continuous-flow nanocatalysis based on metal nanoparticle catalyst-anchored flow reactors has recently provided an excellent platform for effective chemical manufacturing. However, there has been limited progress in porous structure design and recycling systems for metal nanoparticle-anchored flow reactors to create more efficient and sustainable catalytic processes. In this study, traditional paper is used for a highly efficient, recyclable, and even renewable flow reactor by tailoring the ultrastructures of wood pulp. The 'paper reactor' offers hierarchically interconnected micro- and nanoscale pores, which can act as convective-flow and rapid-diffusion channels, respectively, for efficient access of reactants to metal nanoparticle catalysts. In continuous-flow, aqueous, room-temperature catalytic reduction of 4-nitrophenol to 4-aminophenol, a gold nanoparticle (AuNP)-anchored paper reactor with hierarchical micro/nanopores provided higher reaction efficiency than state-of-the-art AuNP-anchored flow reactors. Inspired by traditional paper materials, successful recycling and renewal of AuNP-anchored paper reactors were also demonstrated while high reaction efficiency was maintained. [ABSTRACT FROM AUTHOR]

The contamination of paraquat in vegetables is widely connected with human health risks, leading to the research interest in developing a paraquat sensing system. This work reports a simple detection method of paraquat based on the electrostatic interaction of paraquat and the negatively charged gold nanoparticles (AuNPs), resulting in the changes of colors from red to blue and the shifting of localized surface plasmon resonance (LSPR) peaks of AuNPs. The limit of detection concentration (C LOD ) of this system was 100 μM paraquat. Moreover, among eight cationic salts tested, NaCl was selective to enhance the detection sensitivity of the system, resulting in the reduction of C LOD to 0.10 μM. This system selectively detected paraquat, but not other tested herbicides (ametryn, atrazine, glyphosate, and 2,4-D-dimethyl ammonium). The paraquat-spiking experiment in kale demonstrated the significant recovery rate of paraquat at 96.0-103.0%, and the relative standard deviations were less than 4%. The developed system was efficient for screening contaminated paraquat in vegetables under unwashed and washed conditions. Three out of five unwashed vegetables had a significant level of paraquat as determined by LSPR values. These results suggested the potential application of this system for a simple screening of contaminated paraquat in vegetables. Simple paraquat-screening system was developed based on the negatively charged gold nanoparticles. The limit of paraquat detection of this system was 0.10 μM. This system was potentially used for a simple screening of contaminated paraquat in vegetables., (© 2021 International Union of Biochemistry and Molecular Biology, Inc.)

Shariah money is gold and silver, supplied by the market on profit criterion. Everywhere, government inconvertible paper money arose from bankruptcy. A government with balanced budgets would never need it. Imposed by force, inconvertible paper is a taxation mean, highly inflationary, and causes impoverishment. Unjust and bankrupt governments will continue to force this despotic money. Islamic Monetary Economics refutes the idea of money as a policy tool. Fully convertible paper is Shariah compliant. Shariah requires a just government to balance its budgets and restore fully gold and silver as lawful money. [ABSTRACT FROM AUTHOR]

Today, the emergence of antibiotic resistance in pathogenic bacteria is considered an important problem for society. Excessive consumption of antibiotics, long-term treatments, and inappropriate prescriptions continually increase the severity of the problem. Improving antibiotic stewardship requires improved diagnostic testing, and, therefore, in vitro antibiotic susceptibility testing is becoming increasingly important. This research details the development of an antibiotic susceptibility test for Mycobacterium smegmatis using streptomycin as antibiotics. This strain was selected because it is a member of the slow growing Mycobacterium genus and serves as a useful surrogate organism for M. tuberculosis. A commercially available and low-cost screen-printed gold electrode in combination with a specifically developed nucleic acid probe sequence for the 16SrRNA region of the mycobacterial genome was employed to monitor M. smegmatis nucleic acid sequences using the techniques of square-wave voltammetry and electrochemical impedance spectroscopy. The results show that it was possible to detect M. smegmatis sequences and distinguish antibiotic-treated cells from untreated cells with a label-free molecular detection. As a result, the in vitro antibiotic susceptibility test revealed that M. smegmatis showed sensitivity to streptomycin after a 24-H incubation, with the developed protocol representing a potential approach to determining antibiotic susceptibility more quickly and economically than current methods., (© 2020 International Union of Biochemistry and Molecular Biology, Inc.)

This paper challenges current approaches to undertaking community‐centred disaster recovery. Community‐centred approaches are widely recognised as ‘the gold standard’ for effective recovery from disasters. Yet, they are rarely applied well enough in practice. Challenges include the ‘authority’ culture of command‐and‐control agencies, the emphasis on discrete recovery time frames, and the reluctance to relinquish centralised control. The paper focuses on people's experiences of community‐centred recovery in New South Wales, Australia, which has experienced severe fires and floods since 2019. We undertook key informant interviews and an online survey to inquire into how community‐centred recovery is enacted. Our work uncovered widespread dissatisfaction with current practices. The paper discusses key themes emerging from the research and ends with a call to change how community‐centred recovery is framed and conducted by responding organisations, to include the underlying causes of vulnerability in recovery, to measure success differently, and to alter the narrative of who ‘owns’ disasters. [ABSTRACT FROM AUTHOR]

The article presents the front cover of the periodical; a table of contents for the issue; along with the copyright information of the periodical.

The Back Cover picture shows a renewable wood pulp paper reactor for highly efficient, green, and sustainable chemical manufacturing. This “paper reactor” contains hierarchical micro/nanoscale pores tailored from wood pulp fibers, which can act as both convective‐flow and rapid‐diffusion channels for efficient access of reactants to metal nanoparticle catalysts anchored within the paper reactor, leading to dramatically improved reaction efficiency. More details can be found in the Communication by Koga et al. on page 2560 in Issue 12, 2017 (DOI: 10.1002/cssc.201700576). [ABSTRACT FROM AUTHOR]

A review of the article "Characteristics and Behavior of Hydrothermal Fluids for Gold Mineralization at the Hishikari Deposits", published in the periodical "Resource Geology", is presented.

This study presents the development of an ImageJ plugin for surface characterization. Based on gradient analysis, parameters, such as the gradient magnitude, orientation, mean resultant vector and surface area are derived. A comparative study of supercalendered (SC) papers was performed to verify the surface representations yielded by a laser profilometer. The surface representations of samples covered with carbon and gold were compared to untreated samples. The results confirm the suitability of gold coating for reducing the artefacts encountered on laser profilometry surface representations of paper. In addition, a complete scanning electron microscopy analysis is performed on the assessed samples to quantify the surface fraction covered by mineral fillers and to reveal the true 3D microstructure of SC surfaces. The influence of filler coverage and filler type on the gloss level of commercial SC papers is evaluated. The relationship between the surface topography, gloss and PPS roughness for a series of commercial SC papers is established. [ABSTRACT FROM AUTHOR]

Industrialized economies in the EU depend heavily on imports of minerals. The extraction and parts of the transport and processing of these minerals take place in the Global South and often bear high human rights and environmental risks. A lack of traceability in mineral supply chains makes it particularly difficult to hold companies accountable for negative environmental and social impacts of their operations and those of their suppliers. This paper analyses three mineral supply chains (copper, platinum, and gold) in order to develop propositions about how supply chain‐specific characteristics affect traceability and foreign corporate accountability (FCA) in mineral supply chains. The analytical framework focuses on three dimensions: geopolitical dynamics, industry characteristics, and private governance mechanisms. The authors argue that chain‐specific characteristics may foster or thwart traceability and FCA in mineral supply chains and thus provides a novel contribution to the debate on traceability and accountability in mineral supply chains. [ABSTRACT FROM AUTHOR]

Introduction: This paper explores the fate of South Australia's highly regarded Police Drug Diversion Initiative over the past 10 years. Methods: The paper uses historical and legal analysis, including publicly available data as to rates of drug use, arrests and diversions, media reports, legislation and Hansard debates. Results: In the mid‐2010s, amidst growing anxiety about levels of amphetamine‐type stimulants use in Adelaide, a coroner's report became the poster child for what was seen by the Liberal opposition as the excessive leniency and 'waste of resources' of the Police Drug Diversion Initiative. Despite being universally praised for its efficacy, the Liberal government, when elected, passed amendments to the legislation which 'capped' diversions at two. This ended the period in which diversions from criminal to social justice systems was mandatory for all persons charged with simple drug possession. But since then, the diversion rate in South Australia has plummeted in ways that cannot be explained merely because of these amendments. Discussion and Conclusions: The most highly regarded scheme for diversion of minor drug offenders to treatment is no longer effective. Indeed, the best scheme in the country may now be the worst. The essay draws attention to a catastrophe whose extent is not yet fully appreciated and suggests ways in which we can begin to explain why such a small change has had such dramatic and unforeseen consequences. Like some sort of perverse alchemy, Australia's gold standard for drug diversion has been turned into lead. [ABSTRACT FROM AUTHOR]

We report on random lasing from polymer films containing Rh6G laser dye and gold nanoparticles (AuNPs). Different sizes of AuNP, varying from 10 to 150 nm, were used in the different films, but all had the same mass concentration of gold. We found a strong dependence of the random lasing characteristics (threshold for lasing, the emission intensity, and the spectral narrowing) on the size of the AuNP. In particular, we show that the emission intensity and threshold for lasing versus the NP size qualitatively agree with the prediction of the Mie‐type calculation that considers both the scattering cross section and the absorption of the NP. The experimental spectral narrowing versus the pumping energy is in qualitative agreement with calculations based on diffusion equations (which include appropriate scattering and absorbing terms). This suggests that photon scattering, as enhanced by surface plasmons (SPs) originating on the AuNP, is the dominant underlying mechanism for random lasing of our polymers. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper aims to provide a thorough overview of the ongoing debate about whether artifactual kind terms (such as 'pencil,' 'chair,' 'television,' and so on) have a directly referential or descriptivist semantics. Hilary Putnam (1975) originated the mentioned debate by arguing that artifactual kind terms refer directly ‐ as natural kind terms (like 'water,' 'tiger,' 'gold,' etc.) do ‐ that is, a direct, external relation between the terms and the world determines their extension. However, terms for artifactual kinds appear more likely subjected to a descriptivist view, that is to be defined in terms of conjunctions or clusters of properties. The paper offers a reasoned survey of this debate by pointing out trends and problems associated with each proposed account on the matter. What kind of reference (if any) do terms such as "pencil," "chair," "television," and so on have? On the matter, a debate between directly referential theorists and descriptivist theorists is open. It is largely acknowledged that natural kind terms (such as "water," "gold," "tiger," etc.) are directly referential expressions (cf. Putnam, 1975). That is, they are expressions whose reference is determined by their referents' nature, independent of whether we know or will ever know what this nature is. However, it does not seem likewise convincing that all artifactual kind terms (like "pencil," "chair," "television," etc.) semantically behave the same. Terms for artifactual kinds seem more likely to be subject to a descriptivist view, that is definable not by links to their extensions' nature but in terms of conjunctions or clusters of properties. In his celebrated "The Meaning of 'Meaning'" (1975), Hilary Putnam originated the mentioned debate by arguing that artifactual kind terms also refer directly. Thus, the discussion ultimately revolves around establishing whether artifactual and natural kind terms are both directly referential expressions. The authors engaged in this debate have tried to argue in favor of (or against) Putnam's proposal by highlighting the similarities (or differences) between natural vis‐à‐vis artifactual kind words and their respective referents. This paper aims to provide a thorough and reasoned overview of the debate at stake, pointing out trends and problems associated with each proposed account. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are present not only in the environment but also in drinking water, food, and consumer products. These MPs being toxic, carcinogenic, endocrine disrupting, and genetic risk creators cause several diseases. Despite various approaches, the development of onsite applicable, facile, and quick MP detection methods is still challenging. Here, 3D‐plasmonic gold nanopocket (3D‐PGNP) nanoarchitecture is formed on a paper substrate for simultaneous MP filtration and detection. The paper‐based 3D‐PGNP is integrated with a syringe filter device, and then, MP‐containing solutions are injected through the syringe. Subsequent detection of the MPs using the surface‐enhanced Raman scattering (SERS) successfully identifies the MPs without pretreatment. The interface and volumetric hotspot generation of 3D‐PGNP around the captured MPs significantly improves the sensitivity, which is confirmed by finite‐difference time‐domain simulation. Then, the SERS mapping images obtained from a portable Raman spectrometer are transformed into digital signals via machine learning (ML) technique to identify and quantify the MP distribution. The developed SERS‐ML‐based MP detection method is applied for mixture MPs and for real matrix samples, demonstrating that the method provides improved accuracy. This system is expected to be used for various MPs detection and for environmentally hazardous substances, such as bacteria, viruses, and fungi. [ABSTRACT FROM AUTHOR]

This paper empirically investigates the Gibson Paradox and the Fisher Effect for the UK during different metallic and non‐metallic regimes. The paper applies long‐span monthly data on the long‐term interest rate and the price index from 1790 to 1931. The ARDL cointegration is employed to study the long‐term relationship. Significant evidence is provided for the paradox during the uninterrupted gold standard era of the UK (1821–1914). We also find evidence of the paradox during the short‐term gold exchange standard era (1925–1931). Further results also confirm the Fisher Effect during the 1821–1914 period, providing some backing to its ability to explain the paradox. This is further asserted by the short‐run mutual influence between the rate of interest and the inflation rate. [ABSTRACT FROM AUTHOR]

Peak electron density data derived from GOLD measurements during 2018–2022 are used to analyze the magnitudes and correlations of ionospheric diurnal variability at low latitudes. The correlation distance describes the correlations between spatial locations and is defined in this paper as the angular separation at which the correlation coefficient decreases from 1 to 0.7. Variations in correlation distance with local time, season, magnetic latitude, solar activity, and geomagnetic activity are discussed in this study. The average value of the zonal correlation distance is approximately 8.55° and 3.56° for the meridional direction at low geomagnetic latitudes (magnetic latitudes <30°). The statistical results indicate that both zonal and meridional correlation distances vary little with local time premidnight, while they show pronounced seasonal and latitudinal variations. Both zonal and meridional correlation distances increase with increasing solar activity and decrease with enhancing geomagnetic activity. The EIA strength and gradient mainly modulate the distributions of correlation distances related to magnetic latitude, season, and solar flux level. An empirical model is constructed to describe the temporal and spatial variations in the correlation distance at low latitudes. The study of correlation distances would contribute to a better understanding of ionospheric variability and improvements in data assimilation. Plain Language Summary: The correlation distance is an important parameter in determining the background covariance matrix in data assimilations, which helps to transfer information from observations to the model‐driven background. The study of correlation distances can not only promote a better understanding of ionospheric variability but also improve ionospheric forecasts. More than 1,400 days of GOLD Nmax (peak electron density) data are applied for the statistical analysis of the correlation distance. In general, the correlation distance presents pronounced seasonal and latitudinal variations, varies little with local time premidnight, increases with increasing solar activity, and decreases with enhancing geomagnetic activity. The morphology of the EIA has a direct control on the correlation distance. The EIA strength and gradient mainly modulate the distributions of correlation distances related to magnetic latitude, season, and solar flux level. An empirical model is constructed, and it can effectively describe the temporal and spatial variations in the correlation distance at low latitudes. The results of correlation distances could further improve the accuracy of data assimilation. Key Points: EIA structures directly control the variation of correlation distancesHorizontal correlation distances increase with solar activity and vary with seasonAn empirical model is constructed to describe the variation in correlation distances with LT, mlat, season, solar and geomagnetic activities [ABSTRACT FROM AUTHOR]

The fate of diplomatic gifts after their presentation can reveal patterns of instability and shifting narratives on the items themselves and how they were perceived and received at the time. Often, these important pieces of material evidence disappear or are decontextualised from their exchange. This has been the case with the Persian embassy to Louis XIV's court at Versailles in 1715, where the gifts that were presented to the Sun King were thought to have been lost. This paper traces the afterlives of two of the gifted items: a string of pearls and two gold boxes of mumia. Each of these gifts were retained by the French administration and can be tracked through the eighteenth century. Their journeys reveal much about their evolving significances and the re‐evaluations that occurred once they entered the French collections. [ABSTRACT FROM AUTHOR]

Gold gives a unique luxurious impression and therefore golden objects are often desired. Since gold is an expensive metal, due to its rarity, it is not feasible to produce objects made of gold at reasonable prices. In this study, we have developed a simple representation method that makes real objects appear to be made of gold using projection mapping technology. In recent years, this technology has been extensively explored, mainly in the field of entertainment. Most of these studies were focused on technologies where a target image was superimposed onto an object. Our method, unlike the conventional approach, does not project a target gold image but simply projects a solid color onto an object, thereby giving the perception that the object is made of gold. We have conducted two psychophysical experiments to substantiate our representation method, using stimuli having the same color. Our results indicate that objects were more easily perceived as golden objects when a solid color was projected onto black objects rather than white objects. Furthermore, a few samples were perceived as metals, even though they were actually paper or fabric. These results suggest that when superimposing a solid color onto an object, a change in material type is perceived along with the change of its color. Moreover, we analyzed the relationship between psychophysical evaluations on the perception of projected gold objects and the physical properties of the materials. The results show that the average and the standard deviation of reflectance generated by black objects can be considered factors that affect the perception of a gold-like color. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 522-530, 2017 [ABSTRACT FROM AUTHOR]

In this paper, we present gold‐plating polycarbonate (PC) microchannels. The fabrication of the gold microfluidic channels is achieved by tuning the sequence of reagent insertion into milled and closed submillimeter PC system channels. The resulting gold surface can be utilized in many applications where the benefits of microfluidics, (bio)chemistry of surfaces, and electrochemistry can be combined. Here, we combine the advantages of electrochemistry with microfluidics by mixing the gold sensor with microfluidics. This approach differs from the classic one – the sensor will undergo modifications (e. g. shape and size) depending on the specific scientific problem and will be designed individually; hence its characteristics will be changed. Our goal in this work is to indicate new possibilities for combining two methodologies – electrochemistry and microfluidics. In our work, we emphasize that it confirms the validity of our chosen concept (proof‐of‐concept). In this work, we present one such application, the use of a gold microfluidic channel as a working electrode (WE). We describe the microchip's construction and electrochemical characterization, including the gold flow‐through WE, the Ag/AgCl wire pseudo‐reference, and the Pt auxiliary electrode. The measured current is the result of the flow through a rectangular duct of the gold microchannel electrode embedded in the four walls of the chip. [ABSTRACT FROM AUTHOR]

N‐Heterocyclic carbenes (NHCs) have drawn considerable interest in the field of nanomaterials chemistry as highly stabilizing ligands enabling the formation of strong and covalent carbon–metal bonds. Applied to gold nanoparticles synthesis, the most common strategy consists of the reduction of a preformed NHC‐AuI complex with a large excess of a reducing agent that makes the particle size difficult to control. In this paper, we report the straightforward synthesis of NHC‐coated gold nanoparticles (NHC‐AuNPs) by treating a commercially available gold(I) precursor with an easy‐to‐synthesize NHC‐BH3 reagent. The latter acts as both the reducing agent and the source of surface ligands operating under mild conditions. Mechanistic studies including NMR spectroscopy and mass spectrometry demonstrate that the reduction of gold(I) generates NHC‐BH2Cl as a by‐product. This strategy gives efficient control over the nucleation and growth of gold particles by varying the NHC‐borane/gold(I) ratio, allowing unparalleled particle size variation over the range of 4.9±0.9 to 10.0±2.7 nm. Our strategy also allows an unprecedented precise and controlled seeded growth of gold nanoparticles. In addition, the as‐prepared NHC‐AuNPs exhibit narrow size distributions without the need for extensive purification or size‐selectivity techniques, and are stable over months. [ABSTRACT FROM AUTHOR]

Exospheric temperature is one of the key parameters in constructing thermospheric models and has been extensively studied with in situ observations and remote sensing. The Global‐scale Observations of the Limb and Disk (GOLD) at a geosynchronous vantage point provides dayglow limb images for two longitude sectors, from which we can estimate the terrestrial exospheric temperature since 2018. In this paper, we investigate climatological behavior of the exospheric temperature measured by GOLD. The temperature has positive correlations with solar and geomagnetic activity and exhibits a morning‐afternoon asymmetry, both of which agree with previous studies. We have found that the arithmetic sum of F10.7 (solar) and Ap (geomagnetic) indices is highly correlated with the exospheric temperature, explaining ∼64% of the day‐to‐day variability. Furthermore, the exospheric temperature has good correlation with thermospheric parameters (e.g., neutral temperature, O2 density, and NO emission index) sampled at various heights above ∼130 km, in spite of the well‐known thermal gradient below ∼200 km. However, thermospheric temperature at altitudes around 100 km is not well correlated with the GOLD exospheric temperature. The result implies that effects other than thermospheric heating by solar Extreme Ultraviolet and geomagnetic activity take control below a threshold altitude that exists between ∼100 and ∼130 km. Plain Language Summary: In the terrestrial thermosphere, which is the topmost layer of the collisional atmosphere surrounding the Earth, temperature generally increases with altitude unlike in the troposphere near the surface. However, the thermospheric temperature does not increase indefinitely, but approaches an asymptote, which is referred to as the exospheric temperature, the temperature of the outermost layer of the atmosphere. The Global‐scale Observations of the Limb and Disk (GOLD) instrument, launched into a geosynchronous orbit in 2018, regularly observes atmospheric glow from the Earth's limb, from which we can estimate the terrestrial exospheric temperature (Texo). The GOLD Texo is higher in the afternoon than in the morning and generally increases as solar radiation strength or geomagnetic field variability increases. In this paper, we show that a simple arithmetic sum of the solar and geomagnetic indices can explain a large part of the day‐to‐day Texo variability. Also, Texo has good (poor) correlation with thermospheric parameters such as temperature and density above ∼130 km (at ∼100 km). The behavior suggests that factors other than solar radiation and geomagnetic energy deposition, both of which are correlated well with Texo, take control below a threshold altitude that is between ∼100 and ∼130 km. Key Points: We report on the climatology of exospheric temperature (Texo) measured by NASA‐GOLD in 2018–2021Texo is highly correlated with Ap and F10.7, whose linear combination can explain ∼64% of the Texo day‐to‐day variability in 2018–2021Texo has positive correlation with Swarm thermospheric mass density, GOLD disk temperature, GOLD O2 density, and TIMED/SABER TCI [ABSTRACT FROM AUTHOR]

The article discusses the gold mineralization of the Blue Dot deposit n Kaapvaal Craton, South Africa. It states that the gold ore is hosted in banded iron formation (BIF). It notes that the gold was accompanied by pyrite and mineralization of pyrite that occurred simultaneously with crystallization of iron oxides in BIF. I t mentions that the primary magnetite in BIF was replaced by hermatite or chlorite.

In this paper, we report a gold(I)‐catalyzed cascade cyclization of N‐ or O‐nucleophile tethered‐vinylidenecyclopropanes (VDCPs), resulting in the synthesis of pyrrole, furan, pyrrolidine, and piperidine skeletons in 30%‐98% yields. Depending on the carbon chain length connecting the nucleophile and VDCPs, two reaction pathways are available, leading to different products. Both α‐amino VDCPs and α‐hydroxyl VDCPs, where nucleophiles and VDCPs are connected by a methylene group, undergo intramolecular nucleophilic addition and aromatization, followed by ring‐opening of the cyclopropane unit to produce substituted pyrroles and furans. By extending the chain length to three or four carbons, it becomes possible to form pyrrolidines and piperidines with a cyclobutene moiety via ring expansion of the cyclopropane unit, accompanied by gold carbene induced vinylogous nucleophilic addition. [ABSTRACT FROM AUTHOR]

Metal micropatterns play critical roles in flexible electronics. However, the lack of versatile strategies for micropatterning of diverse metal materials on various thin, flexible or stretchable substrates has limited the rapid development of flexible electronics. Here, a metal micropatterning method by triboelectric spark discharge under atmospheric environment is developed, where a triboelectric nanogenerator (TENG) is employed to precisely and safely control the voltage, current, and frequency of the spark discharges. Micropatterns of metal films like gold, silver, copper, aluminum and platinum are successfully fabricated on substrates of polyimide, polyethylene terephthalate, polyvinyl chloride, polydimethylsiloxane, paper or latex, even on ultrathin substrates (5 μm thick) without damage, where the feature sizes of metal patterns are controllable from 20 μm to 1 mm. Experimental insights into the triboelectric spark discharge behaviors and the pattern feature sizes control are discussed. A straightforward fabrication of metal patterns on the balloon surface or human skin through "handwriting" by a pencil as discharge electrode is realized. Besides metals, extended processibility of conductive materials like carbon nanotubes, graphene, MXene, graphite, carbon fibers, and conductive polymers are also demonstrated. This work proves the possibility of microfabrication by TENG, which is of simplicity and attractiveness for flexible electronics. [ABSTRACT FROM AUTHOR]

This paper introduces an alternative approach for the synthesis of site‐specific gold‐zinc oxide (Au‐ZnO) nanorod array through the pyroelectric approach. The hydrothermally grown ZnO nanorod array on the Si substrate is served as the pyroelectric catalyst. Under rapid temperature oscillation, the gold salt precursor is reduced into gold nanoparticles around the tip of ZnO nanorods in aqueous solution. The hybrid structure shows a significant photoluminescence quenching in the visible emission spectrum of ZnO, which is due to the interaction of ZnO and gold nanoparticles. A Rhodamine B (RhB) degradation test under full spectrum sunlight illumination is conducted to demonstrate the photocatalytic performance of the Au‐ZnO nanorod array. The mechanism behind the hydrothermal growth of ZnO, pyroelectric reduction of gold nanoparticles, and photoluminescence quenching of Au‐ZnO is discussed. The findings of this work offer possible ways to the sustainable use of thermal energy, including harvesting waste heat through pyroelectric effect, and the site‐specific synthesis of various nanomaterials with enhanced photocatalytic degradation capability. [ABSTRACT FROM AUTHOR]

As a typical orogenic gold deposit in Tibet, Shangxu gold deposit is located at the Bangong Lake–Nujiang River Metallogenic Belt in the south of Qinghai–Tibet Plateau. In this paper, zircon U‐Pb dating, trace elements and Hf isotopic analysis were performed on Au‐bearing quartz veins in the Shangxu gold deposit. Zircons from Au‐bearing quartz veins can be divided into three types: detrital, magmatic, and hydrothermal zircons. There are two age peaks in detrital zircons: ca. 1700 Ma and ca. 2400 Ma. There are two groups of concordant ages including 157 ± 4 Ma (MSWD = 0.69) and 120 ± 1 Ma (MSWD = 0.19) in magmatic zircons, in which εHf(t) value of ca. 120 Ma from the magmatic zircons range from +8.24 to +12.9. An age of 119 ± 2 Ma (MSWD = 0.42) was yielded from hydrothermal zircons, and their εHf(t) values vary between +15.7 and +16.4. According to sericite Ar‐Ar age, this paper suggests that an age of 119 ± 2 Ma from hydrothermal zircons represent the formation age of the Shangxu gold Deposit, and its mineralization should be related to the collision between Lhasa Block and Qiangtang Block. The metallogenic age is basically the same as the diagenetic age of Mugagangri granite, and εHf(t) value of hydrothermal zircon is significantly higher than that of the contemporaneous magmatic zircon, which indicates that there is a genetic relationship between the gold mineralization and the deep crust‐mantle magmatism. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to determine whether weight losses from a primarily smartphone-based behavioral obesity treatment (SMART) differed from those of a more intensive group-based behavioral obesity treatment (GROUP) and a control condition (CONTROL).Methods: A total of 276 adults with overweight/obesity were randomly assigned to 18 months of GROUP-based treatment with meetings weekly for 6 months, meetings biweekly for 6 months, and meetings monthly for 6 months and self-monitoring via paper diaries with written feedback; SMART-based treatment with online lessons, self-monitoring, and feedback plus monthly weigh-ins; or a CONTROL condition with self-monitoring via paper diaries with written feedback and monthly weigh-ins.Results: Among the 276 participants (17% men; 7.2% minority; mean [SD] age: 55.1 [9.9] years; weight: 95.9 [17.0] kg; BMI: 35.2 [5.0] kg/m2 ), 18-month retention was significantly higher in both GROUP (83%) and SMART (81%) compared with CONTROL (66%). Estimated mean (95% CI) weight change over 18 months did not differ across the three conditions: 5.9 kg (95% CI: 4.5-7.4) in GROUP, 5.5 kg (95% CI: 3.9-7.1) in SMART, and 6.4 kg (95% CI: 3.7-9.2) in CONTROL.Conclusions: Mobile online delivery of behavioral obesity treatment can achieve weight loss outcomes that are at least as good as those obtained via the more intensive gold standard group-based approach. [ABSTRACT FROM AUTHOR]

Alkanethiolate monolayers formed on rough gold surfaces can, somewhat surprisingly, act as stronger barriers to heterogeneous electron transfer than those on smooth gold surfaces. This paper presents a possible explanation for this observation by constructing simple geometric models of a "rough" and "smooth" gold surface to examine how microscopic roughness differences can affect the nucleation/growth of the adlayer and size/density of structural defects. Expectedly, the number of defects predicted for adlayers formed on smooth gold is lower than any of those for rough gold. The counter‐intuitive result is that the sizes of a small portion of the defects in the adlayer on the smooth surface are larger than any of those found on the rough surface. The potential implications of these results are discussed. [ABSTRACT FROM AUTHOR]

In this paper, we report a sensitive surface‐enhanced Raman scattering (SERS) biosensor for the detection of food‐borne pathogens on the basis of recognition of bacterial cells through the specific targeting agent vancomycin. Vancomycin‐functionalized gold nanostars (GNSs–4–MBA–van) were synthesized as SERS tags for specific and sensitive quantification of food pathogens. The Raman reporter molecule 4–mercaptobenzoic acid (4–MBA) was also a linker molecule to attach vancomycin to gold nanostars. The proposed vancomycin‐based SERS technique achieved a detection limit of 5.7 and 8.2 CFU/ml for Staphylococcus aureus and Escherichia coli, respectively. The logarithm of the bacterial concentration ranged from 101 to 107 CFU/ml and demonstrated a linear relationship with the SERS intensity of the characteristic 4–MBA Raman peak at 1,081 cm−1. Principle component analysis was used to discriminate the two pathogens simultaneously by using reproducible and specific intrinsic fingerprints and intracellular components obtained through SERS. Moreover, the spiking tests revealed that GNSs–4–MBA–van is effective as a potential biosensor for detecting pathogens in the fresh meat and food‐processing industries. [ABSTRACT FROM AUTHOR]

Gold deposits in Jiaodong, termed Jiaodong‐type, are tectonically located in the southeastern margin of the North China Craton. Their major features are reviewed in this paper to highlight the differences between Jiaodong deposits and other genetic types of gold deposits. The mineralization was synchronized with asthenosphere upwelling indicated by syn‐ore OIB‐like mafic dike and large‐scale crustal thinning suggested by decrease of Sr/Y from pre‐ore to syn‐ore granites. Asthenosphere upwelling induced by the roll‐back of Paleo‐Pacific Plate drove partial melting of lithospheric mantle and devolatilization, which induced the release of the ore‐forming fluids. In concomitant with magmatic records, mineralization migrated from the western Jiaobei terrane (133–127 Ma) to the eastern Sulu orogenic belt (114–108 Ma), corresponding to the eastward roll‐back of Paleo‐Pacific Plate. Gold mineralization in Jiaodong formed in the transitions of ductile to brittle deformation, rapid to slow crustal uplift, and regional compression to extension. In the regional‐scale, the gold deposits in the Jiaobei terrane are mostly situated at intersections between NE‐trending faults and EW‐trending basement faults, and gold orebodies dominantly controlled by the lithologic contacts between Precambrian metamorphic rocks and Mesozoic granites. The mineralization was dominated by the disseminated‐veinlet ores related to quartz–sericite alteration in strong cataclasite‐breccia zone, with subsidiary thick quartz‐sulfide veins developed in secondary fault zones. The ore‐forming fluids belong to a H2O–CO2–NaCl±CH4 system and show minor variations in salinity among different types of ore. Structure‐fluid feedback involving fluid‐rock reaction and hydrofracturing triggered the fluid phase separation and resultant gold deposition. The Jiaodong gold deposits are distinct from orogenic and intrusion‐related gold deposits in terms of tectonic setting, origin of ore‐forming fluids, and mechanism of gold deposition. [ABSTRACT FROM AUTHOR]

This Special Issue comprises a selection of the papers given at a two-day discussion meeting held at the University of Melbourne, Australia in June 2009 to celebrate Roger Powell’s 60th birthday. At this milestone, it is fitting to review Roger’s career to date. He has published ∼200 scientific papers on topics that range from low- to high-grade metamorphism, from low- to ultrahigh-pressure (UHP) metamorphism, and from thermodynamics to kinetics. Most of Roger’s papers are multi-authored and address important questions in the petrogenesis of metamorphic rocks. Roger is widely known for his work with Tim Holland to develop the most complete internally consistent dataset of thermodynamic properties of end members of phases necessary to undertake calculations on the conditions of formation and modification of metamorphic rocks. Additionally, Roger and Tim have developed activity–composition models for many of these phases, building on their important methodological developments in formulating such models. Roger is also responsible for the ongoing development ofthermocalc, a thermodynamic calculation software package that may be used to undertake a wide range of phase diagram calculations, including P– T projections, P– T, P– X and T– X, compatibility diagrams and μ–μ diagrams. Together, Roger and Tim have changed the way we carry out quantitative phase equilibria studies. However, Roger’s contributions to metamorphic petrology go well beyond the development of phase equilibria methods and mineral thermodynamics. He has contributed significantly to our understanding of a range of metamorphic processes, and with an extensive array of co-authors has shown how phase equilibria can be used to understand the evolution of metamorphic rocks in general terms as well as in specific terranes. The papers in this Special Issue cover the range from the stabilization of the continents to understanding the formation of orogenic gold deposits, from the stability of sapphirine–quartz-bearing assemblages to the crystallization of melt in migmatites, from the effects of ferric iron and sulphur on the stability of metamorphic mineral assemblages in general to the effects of ferric iron and H2O on the stability of eclogite in particular, and to the quantification of UHP metamorphism. It is our hope that in reading these contributions, you will be stimulated to seek a better understanding of metamorphic processes and to improve our quantification of the variables in metamorphism. [ABSTRACT FROM AUTHOR]

Luminescent security labels are effective platforms for protection of consumer goods from counterfeiting. However, the lifetimes of such security approaches are limited due to narrow‐band photoluminescent features of the label elements, which can be used for the protection technology disclosure. In this paper, a novel concept for the application of non‐linear white‐light luminescence from hybrid metal–semiconductor structures fabricated by direct femtosecond laser writing for the creation of physically unclonable security labels is proposed. A close connection is demonstrated between the internal composition of hybrid structures, which is controlled at the fabrication stage, and their non‐linear optical signals. It is shown that the application of decorrelation procedure based on discrete cosine transform and polar codes for label coding can overcome the problem of the white‐light photoluminescent spectra correlation. The proposed fabrication approach and coding strategy allows reaching a high degree of device uniqueness (up to 99%), bit uniformity (close to 0.5), and encoding capacity up to 1.25 × 10437 in a single label element. The results demonstrate that the barriers for the application of white‐light luminescent nano‐objects for the creation of physically unclonable labels are removed. [ABSTRACT FROM AUTHOR]

Here we compare the global‐scale morphology of Earth's the Far‐Ultraviolet (FUV) emissions observed by NASA's Global‐scale Observations of Limb and Disk (GOLD) mission to those modeled using the Global Airglow (GLOW) code with atmospheric parameters provided by Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (TIEGCM). The O 5S oxygen (135.6 nm) and N2 Lyman‐Birge‐Hopfield (LBH) emissions are observed over the Western hemisphere every 30 min by the GOLD instrument. The FUV brightness of the thermosphere‐ionosphere is expected to vary in systemic ways with respect to geophysical parameters, solar energy input from above, and terrestrial weather input from below. In this paper we examine the O 5S oxygen emission and the N2 LBH emission brightnesses with local time, latitude, season, tides, geomagnetic activity, and solar activity based on GOLD observations and GLOW modeling. Early GOLD observations indicate that the model effectively reproduces the brightness variations with local time and latitude but is biased low in magnitude. However, the TIEGCM is unable to accurately represent the extraordinary nighttime equatorial ionization anomaly observed by GOLD. It is also expected from these results that the signal from geomagnetic storms may obscure tidal signals. Plain Language Summary: In January 2018, a FUV instrument, the Global‐scale Observations of Limb and Disk (GOLD), was launched as a NASA mission of opportunity aboard a geostationary satellite and scientific operations began in October of 2018. GOLD views the entire disk of the Earth every 30 min, allowing the separation of geophysical variability in both space and time. This allows an unprecedented test of global models. Here, we model the Earth's upper atmosphere using the Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (TIEGCM), which produces temperature and the densities of the major chemical components of the neutral atmosphere, ionized plasma densities, and neutral air temperatures. These atmospheric temperatures and densities are used to calculate the Earth's upper atmosphere emissions in the Far‐Ultraviolet (FUV) with the Global Airglow (GLOW) model. The calculated emission rates are then used to compute the expected FUV signals as observed from geostationary orbit. In this paper, we show how the FUV brightness varies with local time, season, atmospheric activity, and solar activity. Of particular interest is that the GLOW model excels at producing FUV brightnesses that match the local time and latitude trends of the daytime observations; however, the model fails to adequately portray the extraordinary nighttime phenomena observed by GOLD. Key Points: The Global‐scale Observations of Limb and Disk (GOLD) instrument observes the Earth in the Far‐Ultraviolet (FUV) from a geostationary orbitGLOW adequately calculates the FUV brightness for various local times, latitudes, solar forcing, and lower atmospheric forcingGLOW calculations indicate the oxygen brightness varies by ±45 R and the effective temperature varies by more than 80 K due to tides [ABSTRACT FROM AUTHOR]

In this paper, the run of the decorating process of the active support, like CeO2, by the gold nanoparticles via deposition‐precipitation method has been studied. Two types of the Au/CeO2 systems with different mean particle size (but the same morphology) of the support have been investigated. It was noted that the decoration process proceeds easily only for large crystals with average size about 67 nm. Three hypotheses were tested in order to explain unsuccessful initial Au nanoparticles decoration of the cube‐like CeO2 crystals with average size about 14 nm as a support. The tests have shown that the ratio of the molar content of the chloroauric acid to the total surface area of the support (MAu/SCeO2) has a significant impact on the decorating process of CeO2 by nano‐Au. If the above ratio is too small, the thin layer of gold instead of the Au nanoparticles is formed on the support surface. In this paper, the calculations of the real surface area (from TEM/HRTEM data) were used to adjust the optimum the MAu/SCeO2 to obtain the Au/CeO2 system with the desired properties. [ABSTRACT FROM AUTHOR]

Accurate measurement of relationship between assets is sensitive to different market conditions in different horizons and has implications for portfolio optimization. Cryptocurrencies are new category of assets that can reduce the risk of well‐diversified portfolio including gold. The paper explores the connections between seven cryptocurrencies and gold at bear (bull) markets across time to uncover the hedging properties of cryptocurrencies for gold investors. Wavelet technique was used to decompose the daily return series of the assets into short‐, medium‐ and long‐term frequencies. Quantile regression (QR) and quantile‐in‐quantile regression (QQR) were applied on the decomposed series to establish the association between the assets over 19 quantiles (τ = 0.05 to 0.95). QR results show all cryptocurrencies as hedges for gold regardless of market regime in the medium to long‐terms. QQR results depict inverse association at bear market but positive association at bull market across time suggesting hedging possibilities at bear markets. Our study provides precise information to investors, regulators and policy makers on risk mitigating strategies for extreme gold market fluctuations across time and market states. [ABSTRACT FROM AUTHOR]

To date, the expansive social science literature on artisanal and small‐scale mining (ASM) in Africa has received little attention from scholars of agrarian political economy. This paper attempts to bridge this gap, based on an in‐depth study of ASM in South Kivu Province of the Democratic Republic of the Congo. The main argument is that the capital–labour social relation underpinning ASM in South Kivu has facilitated the emergence of a capitalist managerial class of dynamic and prosperous rural Congolese. This class has, in turn, been driving increasing sectoral productivity via technological assimilation and capital formation, while also making commercial and productive investments in other, non‐mining sectors. Drawing from the findings, the common conceptualisation of African ASM as a low productivity, subsistence activity is questioned, and the perception in the existing literature that African ASM miners and foreign mining corporations are not in competition for the same mineral deposits is challenged. [ABSTRACT FROM AUTHOR]

Banyumas basin is not only of interest as a hydrocarbon exploration target but also because of its potential to host epithermal gold and porphyry‐type deposits. To date, very few studies have been done on the significance of basin tectonics related to mineralization, but such studies are critically needed. This paper is aimed at reviewing and describing characteristics of gold and base‐metal mineralization that were recently discovered in the Banyumas basin, focusing on the Ajibarang and Majenang blocks, followed by a discussion of the mineral fertility of the basin. Various primary data collected by the authors during fieldwork with several mineral exploration companies together with data from current research results are reviewed, interpreted, and discussed. Two different styles of gold mineralization are recognized, that is, carbonate‐base metal‐gold/intermediate‐sulphidation epithermal mineralization in the Ajibarang Block and porphyry‐style mineralization in the Majenang Block, which occur in close proximity to each other (40–50 km distance) in different geological settings. The Ajibarang mineralization is hosted by a turbidite sedimentary sequence forming part of the Halang Formation, which is phreatically brecciated (diatreme), whereas the Majenang mineralization was formed in the Kumbang Formation in a volcanic and intrusive (diorite) environment. Diatreme breccias associated with gold‐base metal mineralization in the Ajibarang Block may be related to remnant hydrothermal activity, recognized in Landsat TM imagery as circular structures. However, it remains unclear whether any volcanic/intrusive activity was directly involved in the formation of the mineralization. In contrast, the Majenang porphyry mineralization is clearly related to magmatism as it is hosted by volcanics of the Kumbang Formation and a diorite as the causative intrusion. The recent discovery of mineralization in both locations suggests the mineralization fertility of the Banyumas basin may be significant, making the region a valuable target for future exploration. [ABSTRACT FROM AUTHOR]

This paper proposed the principle of the plating lack occurrence in MLED product in electroless nickel immersion gold (ENIG) process and solved the risk of film cracking during ENIG by optimizing the stress and thickness of BP process related films to avoid plating lack problem. [ABSTRACT FROM AUTHOR]

This study analyses the dynamic linkages between oil and gold prices for the spot and 1‐ to 12‐month futures markets using monthly data over the period 1983–2016. To do this, we use the rolling and recursive rolling Granger causality approaches. The distinguishing feature of this study from the previous studies is that this is the first study investigating the causal links between oil and gold using time‐varying causality tests. The findings show that the causality links between oil and gold display strong time variation. Although causal links are not detected for most of the study period, strong bidirectional or unidirectional causality is found in several subsamples. The duration of the periods with causality links varies from a few months to 3 years, whereas the duration for the noncausality periods might be 15 years long. By date stamping the causality links between oil and gold, our paper discovers that causality from oil to gold is related to large oil price changes, whereas causality from gold to oil is related to large financial crises. The evidence obtained in the paper points out the dangers of assuming a constant causality link between oil and gold markets because these links might break down unexpectedly. Our findings point out to the dangers of assuming noncausality between oil and gold particularly in hedging oil price risk using gold. [ABSTRACT FROM AUTHOR]

Option-pricing models that assume a constant interest rate may misprice futures options if the interest rate fluctuates significantly or if the price of the underlying asset is correlated with the interest rate. The futures option-pricing model of Ramaswamy and Sundaresan allows for a stochastic interest rate and correlation of the underlying asset's price with the interest rate. Using a data set of daily closing prices for Comex gold futures options, this paper tests the Ramaswamy and Sundaresan model against a constant interest rate model. Results indicate that the stochastic interest rate model is a superior predictor of market prices. [ABSTRACT FROM AUTHOR]

Small-scale mining supports the livelihoods of several hundred thousand rural households in Africa. Nonetheless, the understanding of the organizational dynamics of small-scale miners' activities is modest. The paper outlines the small-scale mining codes in Tanzania and contrasts them to prevalent organizational practices in two Tanzanian small-scale mining settlements. It is argued that there is a need to adjust the regulatory mechanisms to well-consolidated practices: If basic practices differ substantially from official prescriptions of the mining codes over an extended period of time, certain elements of the regulatory framework need reconsideration. The paper examines three pertinent operational components that vary in form and managing practices between the two study sites: dealing with licence acquisition, accessing working capital, and sharing output. These components are considered vital for the proper manoeuvring of local small-scale mining operators and the reasons for the variations are essential to understand for policymakers and development practitioners. By incorporating prevalent practices and context-dependent variations in some of the crucial organizational components, it is possible to design a robust and resilient regulatory framework for small-scale mining. A number of policy adjustments are consequently proposed. [ABSTRACT FROM AUTHOR]

Gold as a vital hedging asset plays increasing critical roles in risk management during turmoil macroeconomic environments. For the massive and indistinct impactors of gold price volatility, this paper tries to investigate whether the short‐ and long‐term asymmetry, extreme observations, and jump components in past gold volatility help to obtain higher forecasting accuracy in future volatility from both in‐sample and out‐of‐sample perspectives. A variety of evaluation methods are utilized to compare the performances of GARCH‐MIDAS models incorporating these volatility components and the standard ones without them. The results of in‐sample estimation show first that all the short‐term and long‐term asymmetry, extreme observations, and jump components have significantly impact on gold volatility. The evaluation results of out‐of‐sample forecasts suggest that the forecasting accuracy of gold volatility can be significantly improved by most of the extended GARCH‐MIDAS models including asymmetry, extreme observations, and jump components. The model including short‐term jump intensity and the model with both long‐term asymmetry and long‐term leverage effects have better forecasting performances than other models for gold volatility, especially for regular volatility. Moreover, GARCH‐MIDAS models incorporating long‐term leverage and long‐term jump have better performances in forecasting accuracy of extreme gold volatility. [ABSTRACT FROM AUTHOR]

The influence of the size and oxidation state of Au nanoparticles (AuNPs) as electrocatalysts for the electro-oxidation of cellulose was studied. Carbon paper electrodes modified with AuNPs were used as the electrocatalysts for the electro-oxidation of cellulose dissolved in 1.3 m NaOH. The size and oxidation state of the AuNPs were determined by using SEM, TEM, and X-ray photoelectron spectroscopy. Both the size and the oxidation state of the AuNPs were found to influence the electrocatalytic properties of the electrode, as studied by using cyclic voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy. The carbon paper electrodes decorated with AuNPs (less than 25 nm) that consist of metallic Au gave rise to a significantly higher electrocatalytic activity than a bare polycrystalline Au electrode. [ABSTRACT FROM AUTHOR]

In this paper, we examine the effect of the gold price on the American financial market. In particular, we analyse the impact of gold price on dollar exchange rate and returns of the American banks. Methodologically, we use a unified approach based on multi‐models not only to examine the gold price and U.S. market nexus but also to highlight the dynamics of such relationship over the period December 19, 1994–June 30, 2017. We show that a long‐relationship between gold price, dollar exchange rate and U.S. bank returns is well documented. As well, the behaviour and dynamics of such relationship are characterized by some salient features. In particular, the nonlinear adjustment of gold price against the U.S. financial market is well documented, implying that gold price plays a substantial role in creating a pressure on the dollar exchange rate and U.S. banks returns. Such findings could provide interesting insights for policymakers and investors. [ABSTRACT FROM AUTHOR]