Gold Foil Research Articles

Husby in Glanshammar: cloisonné production, Viking Period silver deposition and memorialisation

Abstract This paper returns to Husby in Glanshammar, Sweden, where an important manorial settlement of the mid-to-late 1st millennium AD was excavated in the 1990s for a highway project. A recent intensive and comprehensive metal detector survey of the site’s surviving parts has secured additional finds that cast a new light on the manor and its afterlife. Fine copper alloy casting was amply demonstrated by the 1990s excavations. Now a die for the making of waffled gold foil has been added to this assemblage. Waffled foils formed part of gold-and-garnet cloisonné work, one of the most exclusive decorative techniques of the era. Hacksilver and coins from around AD 900 were found scattered over the old foundation of the torn-down mead-hall, apparently forming a first phase of memorialisation that continued from about AD 1100 onward with a small Christian cemetery next to the foundation. These single coins go back at least half a century before the start of silver hoarding in the region. The silver found at Husby shows clear signs of having been used as bullion in economic transactions, with a high degree of fragmentation and many test marks.

Autonomous Chemistry Enabling Environment-Adaptive Electrochemical Energy Storage Devices

Autonomous Chemistry Enabling Environment-Adaptive Electrochemical Energy Storage Devices

Burial of the Pazyryk Elite Members at Khankarinsky Dol, Northwestern Altai

This article presents the results of an interdisciplinary study of kurgan 30 at Khankarinsky Dol, located on the left bank of the Inya River, 1–1.5 km southeast of Chineta, Krasnoshchekovsky District, Altai Territory (northwestern Altai). This is a Pazyryk kurgan, under which a looted double burial of a male and an adolescent was found. Their heads were apparently oriented toward the east. Along the northern wall of the grave, an accompanying burial of seven horses was found, placed in two rows, heads oriented to the east. The morphological analysis showed all of them to be stallions, resembling those from other mounds of this group. Morphological comparison with horses from other Pazyryk kurgans in the Altai revealed both similarities and differences. Analysis of the grave goods, including iron bits, a bone pipe-shaped bead, tiny bronze daggers in wooden scabbards, a pickaxe, numerous fragments of gold foil from the horse harness, and fragments of Chinese wooden lacquer ware, suggests that the burial was made no earlier than the 4th century BC – possibly in the late 4th to early 3rd century BC. Radiocarbon analysis was carried out at the Tomsk Institute for Monitoring Climatic and Ecological Systems of the SB RAS Center for Isotopic Studies. The funerary rite and the artifacts suggest that kurgan 30 was constructed for members of the nomadic elite of the northwestern Altai.

Microstructure, phase composition and hardness of Ti–Au cladding deposited on Ti–6Al–4V substrate by electron beam powder bed fusion method

In this study, a Ti–Au cladding was deposited on a substrate from the Ti–6Al–4V alloy by the electron beam powder bed fusion method in a vacuum. The main goal was to assess the possibility of using titanium powders and gold foils as a feedstock for additive manufacturing of such dental products. The microstructure, chemical element distributions, phase composition and hardness of the formed Ti–Au alloy were studied using optical microscopy, energy dispersive X-ray analysis, as well as X-ray diffraction and nanoindentation tests. Gold-containing intermetallic compounds were observed through the entire cladding thickness. The α-Ti, α-Au, AuTi and AuTi3 phases were found, in addition to the Ti3Au one, which provided hardness values greater than those of conventional titanium alloys. It was shown by results of the crystal-geometric and X-ray phase analysis that the AuTi3 phase possessed the most densely packed A15 structure. This fact correlated with the obtained data on the deviation of the atomic volume per ion from Zen's law and the high hardness levels. Metallurgical patterns of the microstructure formation that affected the functional properties of such claddings were discussed and a further research direction was proposed.

Material Characteristics and Comparison of Silver Foil Glass Beads Excavated from the Tomb of King Muryeong in Korea

This study investigated the comprehensive characteristics of silver foil beads excavated from the Tomb of King Muryeong, based on composition analysis of the foil and glass and morphological characterization. The major element components of metal foil and glass were investigated using a scanning electron microscope (SEM) equipped with an Energy Dispersive X-ray spectrometer (EDS). Trace elements were determined using LA-ICP-MS to constrain the source of the raw material. The morphological characteristics of the beads were recognized through an optical microscope. As a result of the analysis, the metal foil was detected as pure in both gold- and silver-colored glass beads. The chemical composition of the glass was determined as a soda glass, with Na+ acting as a flux and CaO added as a stabilizer to improve durability. It was confirmed that plant ash was used because MgO and K2O were found to contain more than 1.5%. Through trace element analysis, it was confirmed that the gold and silver-colored silver foil glass beads were made of plant ash glass using different materials. The content of Fe2O3 was significantly higher in the gold-colored silver foil glass beads than in the silver-colored silver foil glass beads. Therefore, it can be interpreted that the gold-colored silver foil glass beads excavated from the tomb of King Muryeong intentionally achieved the appearance of gold foil glass beads by controlling the color of the outer glass. The silver foil glass beads showed morphological differences according to the color of the outer glass. The gold-colored silver foil glass beads were manufactured as single or segment types, but the silver-colored silver foil glass beads were manufactured as segment types.

Studies on the Effect of Graphene Oxide Deposited on Gold and Nickel Microsieves on Prostate Cancer Cells DU 145.

This work shows the effect of graphene oxide deposition on microsieves’ surfaces of gold and nickel foils, on DU 145 tumor cells of the prostate gland. The sieves were made by a laser ablation process. The graphene oxide (GO) deposition process was characterized by the complete covering of the inner edges of the microholes and the flat surface between the holes with GO. Electron microscanning studies have shown that due to the deposition method applied, graphene oxide flakes line the interior of the microholes, reducing the unevenness of the downstream surfaces during the laser ablation process. The presence of graphene oxide was confirmed by Fourier infrared spectroscopy. During the screening (sieving) process, the microsieves were placed in a sieve column. Gold foil is proven to be a very good material for the screening of cancer cells, but even more so after screening as a substrate for re-culture of the DU 145. This allows a potential recovery of the cells and the development of a targeted therapy. The sieved cells were successfully grown on the microsieves used in the experiment. Graphene oxide remaining on the surface of the nickel sieve has been observed to increase the sieving effect. Although graphene oxide improved separation efficiency by 9.7%, the nickel substrate is not suitable for re-culturing of the Du 145 cells and the development of a targeted therapy compared to the gold one.

Eco-friendly and rapid extraction of gold by in-situ catalytic oxidation with N-bromosuccinimide

Gold is a valued, critical element whose chemical activation or extraction is challenging. Non-cyanide extraction of gold is now the focus, and N-bromosuccinimide(NBS) is attracting attention. Herein, new insights into the possible mechanism are deeply revealed through comprehensive analysis and detection of the reaction by using elementary gold and gold bearing ore. Experiments on gold foil indicate that Au can be activated in NBS solution to perform a satisfactory dissolution. Application of NBS in gold extraction from ore show a high yield of 86.24% under optimal conditions of NBS dosage 0.05 M, liquid-solid ratio 4:1, stirring speed 400 rpm, pH 8, 25 °C and leaching for 20 h, while yields of other coexisting metals are nearly negligible. The process leads to direct, efficient, one-pot conversion of gold, into simple water-soluble salts. Characterizations show that the framework of NBS are not destroyed, only bromine separates from the framework. The oxidation of neutral gold atom to trivalent Au(III) occurs in a mild, clean and room-temperature chemistry, which converts gold to [AuBr4]-, and the framework to succinimide. The active bromine and radical Br (Br•) generated from in-situ autocatalysis of NBS are responsible for this. The systematic results herald a green procedure for preparation of gold derivatives and gold extraction industry.

Бронзовый таз из погребения кургана № 1 группы «Богомольные пески I» в Нижнем Поволжье

The article dwells on the find of the bronze basin in the burial no. 5 of the kurgan no. 1 of the group “Bogomol’nye peski I” near the village of Nikolskoye, Enotaevsky District, Astrakhan Region. A belt-set of gold with turquoise inlays found in the region of the pelvic bones of a 40–45-year-old warrior, an iron dagger in a wooden scabbard with round-shaped iron overlays covered with gold foil and with turquoise inlays, and other finds allowed the author of the excavations to attribute the burial to the 1st–2nd centuries AD. It is obvious that the buried warrior belonged to the nomadic elite. A bronze basin, standing almost vertically, was leaning against the northern side of the grave-pit at its bottom. The analysis has shown that the basin belongs to a rare variant, till now unknown in Sarmatia. The closest parallel of its edge with a rim bent outwards and decorated with a band of Ionian kymation is a basin from the prince’s burial in Hoby on the island of Lolland in Denmark, usually dated in the first half of the 1st century AD. The peculiarities of the rosette design at the bottom of the basin associate it with a Tassinari S2300 type basin from Pompeii and some bronze paterae of the Eggers 154 / Nuber D type (Hagenow), which also indicates a probable dating no later than the first half or the middle of the 1st century AD. The basin demonstrates clear signs of deliberate damage. Not only the foot-ring and handles were lost, but the body itself was punched in several places in the form of wedge-shaped holes from the blows of a knife or dagger (?), which are very close in shape to the holes on the silver phalerae and the bowl of the Parthian circle of the second half of the 2nd – first half of the 1st century BC from the Trans-Volga region.

Light ‘Em up: Efficient Screening of Gold Foil Grids in Cryo-EM

Transmission electron cryo-microscopy (cryo-EM) allows for obtaining 3D structural information by imaging macromolecules embedded in thin layers of amorphous ice. To obtain high-resolution structural information, samples need to be thin to minimize inelastic scattering which blurs images. During data collection sessions, time spent on finding areas on the cryo-EM grid with optimal ice thickness should be minimized as imaging time on high-end Transmission Electron Microscope TEM systems is costly. Recently, grids covered with thin gold films have become popular due to their stability and reduced beam-induced motion of the sample. Gold foil grids have substantially different densities between the gold foil and ice, effectively resulting in the loss of dynamic range between thin and thick regions of ice, making it challenging to find areas with suitable ice thickness efficiently during grid screening and thus increase expensive imaging time. Here, an energy filter-based plasmon imaging is presented as a fast and easy method for grid screening of the gold foil grids.

The pigment analyses of Cambodian panel painting at national museum of Cambodia

Most of panel paintings in Cambodia were destroyed by climate, insects and war; especially during Khmer Rouge (1975–1979). A few paintings were studied for materials and techniques. In this research, we focus on the pigment analyses of the early 20th century Cambodian panel paintings on the wooden doors and windows in the gallery of bronze, National Museum of Cambodia. The EDX and XRD techniques were applied to determine the elemental compositions and identities of the pigments used in the paintings. The results suggested the presence of lead white, calcite, Prussian blue, red cinnabar, red ochre, red lead, gypsum, emerald green (clinoclase), organic black, organic brown with the base of blanc fixe and gold leaf in the paintings.The cross sections of paint samples showed various layers; wood support, ground and paint layers. The ground layer was composed of kaolin while various white pigments like calcite, lead white, blanc fixe and gypsum were found in the paint layer. This indicated the use of white pigment(s) in combination with another colored pigment(s).

Selective Chemical Vapor Deposition Growth of WS2/MoS2 Vertical and Lateral Heterostructures on Gold Foils.

Vertical and lateral heterostructures consisting of atomically layered two-dimensional (2D) materials exhibit intriguing properties, such as efficient charge/energy transfer, high photoresponsivity, and enhanced photocatalytic activities. However, the controlled fabrication of vertical or lateral heterojunctions on metal substrates remains challenging. Herein, we report a facile and controllable method for selective growth of WS2/MoS2 vertical or lateral heterojunctions on polycrystalline gold (Au) foil by tuning the gas flow rate of hydrogen (H2). We find that lateral growth is favored without H2, whereas vertical growth mode can be switched on by introducing 8–10 sccm H2. In addition, the areal coverage of the WS2/MoS2 vertical heterostructures is tunable in the range of 12–25%. Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) results demonstrate the quality and absence of cross-contamination of the as-grown heterostructures. Furthermore, we investigate the effects of the H2 flow rate on the morphology of the heterostructures. These pave the way to develop unprecedented 2D heterostructures towards applications in (opto)electronic devices.

Investigation of Wood Species and Conservation Status of Wooden Seated Amitabha Buddha Triad and Wooden Amitabha Buddha Altarpiece of Yongmunsa Temple, Yecheon, Korea (Treasure)

The Wooden Seated Amitabha Buddha Triad and Altarpiece have not been the subjects of definitive species identification and scientific analysis. In this study, visual investigation, portable X-ray fluorescence (p-XRF), species identification, and lacquer layer observations were carried out to determine the original materials and conservation status. Cracks, exfoliation and discoloration were detected during the visual investigation. The p-XRF data indicated that chrome oxide green, malachite, gold, cadmium red, cinnabar, minium, hematite, lead white, ink stick (Carbon), and copper were used for pigments and the coronet accessory. Tilia spp., Abies spp., and Pinus spp. were identified from both the Buddha Triad and Altarpiece. Finally, lacquer layer analyses of the base layer, lacquer layer, orange pigment layer, and gold leaf layer observed modern synthetic pigments likely used in previous conservation. As the Korean Cultural Heritage Charter and the International Charter for the Conservation and Restoration of Monuments and Sites clearly state that objects of cultural heritage must be conserved using their original materials, future conservation of these objects should utilize the data obtained in this study to employ traditional materials. Furthermore, a deterioration map diagnosis can be applied together with the obtained analysis data to understand the conservation status of and inform an appropriate and authentic conservation treatment for the Buddha Triad and Altarpiece.

Label-free and sensitive microRNA detection method based on the locked nucleic acid assisted fishing amplification strategy.

Herein, a label free and sensitive miRNA detection method with enhanced practical applicability was developed based on the locked nucleic acid (LNA) assisted repeated fishing amplification strategy. The working mechanism of the proposed method is as follows: 1) a DNA probe (i.e, L-DNA) with LNA bases is immobilized onto the surface of a gold foil. The L-DNA hybridizes with the 3' terminus of the first strands of complementary deoxyribonucleic acid (cDNA) of the target miRNA in the test samples; 2) The protruding 5' terminus of the cDNA serves as a 'fishhook' to repeatedly fish the products of a hybridization chain reaction (HCR) out from a 'reaction tube'; 3) The HCR products can be unloaded from the gold foil into a 'product tube' through temperature-controlled dehybridization; 4) The concentration of the target miRNA is determined based on the fluorescence intensity generated by the addition of SYBR-Green I (SG) into the 'product tube'. The proposed platform was applied to the detection of miRNA-122 in cell lysate samples and obtained quantitative results with accuracy comparable to the quantitative reverse transcription PCR method (qRT-PCR). It is worth pointing out that the proposed platform achieved a limit of detection value of 2.9fM for miRNA-122 by a simple but effective LNA-assisted repeated fishing amplification strategy instead of complicated enzyme-based amplification techniques. It is reasonable to expect that the proposed method provides a competitive alternative for designing practically applicable, cost-effective and label-free miRNA detection methods.

Device-Scaled Controlled Crumpling of MXene-Based Ultrathin Supercapacitors as Stretchable Power Sources

Two-dimensional transition-metal carbide (MXene) Ti3C2Tx possesses advantages of high conductivity and high volumetric capacitance, making it an ideal electrode material for high-performance supercapacitors. However, the high stiffness impedes its direct implementation in stretchable supercapacitors for integrated wearable electronics. Here, we demonstrate a stretchable supercapacitor based on Ti3C2Tx electrodes through a device-scaled controlled crumpling strategy. An ultrathin supercapacitor with a thickness of about 45 μm is assembled with gold foil gilded ultrathin preservative membrane as a current collector, drop cast Ti3C2Tx as an active material, and poly(vinyl alcohol)-H3PO4 as a polymer gel electrolyte. The ultrathin supercapacitor with optimized electrodes exhibits an areal specific capacitance of 10.2 mF cm–2 at 5 mV s–1 with excellent mechanical flexibility. The controlled adhesion of the ultrathin supercapacitor on a prestretched latex substrate and the elastic deformation of the substrate induce local displacements on the ultrathin supercapacitor to create periodic crumples. Stretching the crumpled supercapacitor only causes the amplitude and wavelength changes of the crumples, leading to a high level of stretchability (up to 100%). Also, the crumpled supercapacitor can sustain 1000 stretching cycles at a maximum strain of 100%. Moreover, it can provide sufficient power to drive α-In2Se3 nanoflake-based photodetector at 100% strain. This device-scaled controlled crumpling method provides a facile and effective way to design stretchable energy devices with high stretching durability for stretchable devices.

Electro-assisted printing of soft hydrogels via controlled electrochemical reactions

Hydrogels underpin many applications in tissue engineering, cell encapsulation, drug delivery and bioelectronics. Methods improving control over gelation mechanisms and patterning are still needed. Here we explore a less-known gelation approach relying on sequential electrochemical–chemical–chemical (ECC) reactions. An ionic species and/or molecule in solution is oxidised over a conductive surface at a specific electric potential. The oxidation generates an intermediate species that reacts with a macromolecule, forming a hydrogel at the electrode–electrolyte interface. We introduce potentiostatic control over this process, allowing the selection of gelation reactions and control of hydrogel growth rate. In chitosan and alginate systems, we demonstrate precipitation, covalent and ionic gelation mechanisms. The method can be applied in the polymerisation of hybrid systems consisting of more than one polymer. We demonstrate concomitant deposition of the conductive polymer Poly(3,4-ethylenedioxythiophene) (PEDOT) and alginate. Deposition of the hydrogels occurs in small droplets held between a conductive plate (working electrode, WE), a printing nozzle (counter electrode, CE) and a pseudoreference electrode (reference electrode, RE). We install this setup on a commercial 3D printer to demonstrate patterning of adherent hydrogels on gold and flexible ITO foils. Electro-assisted printing may contribute to the integration of well-defined hydrogels on hybrid electronic-hydrogel devices for bioelectronics applications.

Non‐protein amino acids identified in carbon‐rich Hayabusa particles

AbstractAmino acid abundances in acid‐hydrolyzed hot water extracts of gold foils containing five Category 3 (carbon‐rich) Hayabusa particles were studied using liquid chromatography with tandem fluorescence and accurate mass detection. Initial particle analyses using field emission scanning electron microscopy with energy‐dispersive X‐ray spectrometry indicated that the particles were composed mainly of carbon. Prior to amino acid analysis, infrared and Raman microspectroscopy showed some grains possessed primitive organic carbon. Although trace terrestrial contamination, namely l‐protein amino acids, was observed in all Hayabusa extracts, several terrestrially uncommon non‐protein amino acids were also identified. Some Hayabusa particles contained racemic (d≈l) mixtures of the non‐protein amino acids β‐aminoisobutyric acid (β‐AIB) and β‐amino‐n‐butyric acid (β‐ABA) at low abundances ranging from 0.09 to 0.31 nmol g−1. Larger abundances of the non‐protein amino acid β‐alanine (9.2 nmol g−1, ≈4.5 times greater than background levels) were measured in an extract of three Hayabusa particles. This β‐alanine abundance was ≈6 times higher than that measured in an extract of a CM2 Murchison grain processed in parallel. The comparatively high β‐alanine abundance is surprising as asteroid Itokawa is similar to amino acid‐poor LL ordinary chondrites. Elevated β‐alanine abundances and racemic β‐AIB and β‐ABA in Hayabusa grains suggested these compounds have non‐biological and plausibly non‐terrestrial origins. These results are the first evidence of plausibly extraterrestrial amino acids in asteroid material from a sample‐return mission and demonstrate the capabilities of the analytical protocols used to study asteroid Ryugu and Bennu samples returned by the JAXA Hayabusa2 and NASA OSIRIS‐REx missions, respectively.

A Clinical Presentation of the Direct Gold/Composite Sandwich Restoration.

The intent of this paper is to present a new idea for increasing the life expectancy of class II composite restorations where the proximal marginal seal is compromised by the necessity to rely on dentin bonding. As implied by the Clinical Relevance statement, studies show that bonding to dentin in areas with high levels of bacterial action, combined with sustained high plaque formation, tends to be the "Achilles heel" with regard to sustained long-term restorations. Therefore, this paper will present a thought experiment, combined with clinical evidence, for combining gold foil with composite in these areas for the class two composite restoration. The results, if proven viable, will be to develop a procedure utilizing the properties of gold foil that make it one of the longest-lasting restorative materials with the recent development of modern cosmetic materials for a truly long-lasting and healthy class II restoration.

Early Medieval burial complex of the burial mound of Maslennikovo I in the Samara Volga region

This paper is devoted to the publication of materials obtained during the study of the burial of the early Middle Ages in the burial mound Maslennikovo I. This necropolis is located in the steppe southwestern part of the Samara Trans-Volga region. The excavated mound 1 was built in the Bronze Age in the process of making eight burials of this time. Burial 2, admitted into the floor of the embankment in its southern part, dates back to the Middle Ages. The burial was made in a grave pit in the shape of an elongated oval and oriented with its long axis along the NW-SE line. The buried man lay stretched out on his back with his head to the northwest. The bone of a horses leg lay at his head. Gold foil fragments, which may have been the remains of a symbolic death mask, and earrings were also found in the area of the head. The remains of a wooden object with silver plates at the edges, probably of a quiver on the chest of a deceased burial were found. The remains of a scabbard, which also had silver plates there were in the region of the pelvis and between the thigh bones. Seven silver sewn-on plaques with embossed ornaments and several poorly preserved iron objects were found in the grave. The peculiarities of the funeral rite and accompanying implements make it possible to include this complex in the number of burials attributed by researchers as Magyar (proto-Magyar, Hungarian) and to consider it as the burial of an individual integrated into the ethnocultural environment of the Hungarians of the Middle Volga region of the 9th-10th centuries.

Clad Gold Leaf KIRIKANE at Traditional Japanese Fine Crafts

Clad Gold Leaf KIRIKANE at Traditional Japanese Fine Crafts

Art’s Work in the Age of Biotechnology: Shaping Our Genetic Futures

Art’s Work in the Age of Biotechnology: Shaping Our Genetic Futures