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Foraminifera are unicellular eukaryotes known to have a shell, called test, generally made of secreted calcite (CaCO3). We report for the first time a Foraminifera having a composite calcite/opal test in the cosmopolitan and well-studied benthic species Bolivina spissa (Rotaliida), sampled from the Sagami Bay in Japan at 1410 m depth. Based on comprehensive investigations including Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-ray Spectroscopy (EDS) and Fourier Transform Infrared Spectroscopy (FTIR), we inspect the morphology and composition of the novel opaline layer coating the inside part of the calcitic test. Using Scanning Transmission Electron Microscopy (STEM) and EDS analyses, we detected probable Silica Deposition Vesicles (SDVs), organelles involved in opal precipitation in other silicifying organisms, confirming that the Foraminifera themself secretes the opal layer. The layer was systematically found in all studied individuals and had no apparent sub-structure. Its thickness showed an analogous growth pattern with the calcitic shell of B. spissa, being the thickest in the oldest chamber (proloculus) and becoming thinner toward the younger chambers (apertural side). Its absence in the youngest chambers indicates that silicification occurs subsequently to calcification, probably discontinuously. We further discuss the potential function(s) of this composite test and propose that the opal layer may serve as a protection barrier against predators using either mechanical drilling or chemical etching of the calcitic test. Isotopic composition measurements performed separately on the proloculus part and the apertural side of B. spissa suggest that the presence of an opal layer may alter the calcitic isotopic signal and impact paleoenvironmental proxy using foraminifer's tests composition. If silicification in Foraminifera was found to be more widespread than previously thought, it could possibly have important implications for foraminiferal evolution, palaeoceanographic reconstructions, and the silica cycle at global scale. [ABSTRACT FROM AUTHOR]

Nickel selenide thin films were grown on glass substrates at room temperature using the successive ionic layer adsorption and reaction (SILAR) method. Optical and structural analyses of the thin films were also performed. X‐ray diffraction (XRD), energy dispersive x‐ray analysis (EDAX) and scanning electron microscopy (SEM) were used for structural analysis, and UV–vis spectrometer was used for optical analysis. The XRD results indicate that the NiSe2 thin films had a polycrystalline structure. As a result of the optical analysis, the bandgap value decreased from 2.56 to 2.25 eV as the thickness increased. These results suggest that increasing film thickness improves the crystal structure of NiSe2 thin films. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Two artefacts in royal custody, an étagère (inventory number HGK401) and a writing desk (inventory number HGK1249), that display specific aspects of Swedish Rococo furniture in an exciting combination, are re-examined through scientific means. Microscopy of cross sections, wood species identification, scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray fluorescence microscopy, and pyrolysis-gas chromatography-mass spectrometry analyses reveal some of their physical and chemical characteristics. The results show that the original wood includes hinoki, and the actual urushi ware originates from at least two different artefacts, of which one was made in Japan. A specific mixture of saps hitherto only confirmed on historical Ryukyu Island urushi artefacts was detected. Blue coloured urushi is verified. [ABSTRACT FROM AUTHOR]

For an SF6 circuit breaker in capacitor bank‐making operation, the inrush current may cause serious erosion to its arcing contacts. In order to observe the characteristics of this erosion, an arc extinguish chamber of SF6 circuit breaker with Cu–W arcing contacts was designed, and experiments of capacitor bank making were carried out. The prebreakdown arcing duration and inrush current were measured, and the mass loss of the contact after 100 times of operation was calculated. Power–frequency‐withstanding voltage was measured after every 20 operations. The surface status, scanning electron microscope (SEM), and energy dispersive x‐ray spectroscopy (EDS) of the contact material were recorded. The characteristics and mechanism of arcing contact erosion in SF6 circuit breaker in the making process were then analyzed. Compared to the case of breaking high current, this analysis found two major mechanisms that lead to severe arcing contact erosion in the case of capacitor bank making operation, namely, the arc erosion due to prebreakdown current and the erosion of arc heated contact due to friction. The erosion after contact caused by mechanical friction occupies a relatively larger proportion in the mass loss of contact materials. Under the conditions of 3 m/s making velocity, 18 kA current peak, and less than 2 ms arcing duration, the mechanical wear mass loss rate is greater than 1.0 mg/C. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

Abstract The leaching from mine tailings results in contamination of nearby groundwaters and rivers by hazardous metals like copper (Cu), zinc (Zn), and iron (Fe). In this study, unweathered tailings samples at depths of 1 to 3 m were collected from a tailings dam of an abandoned mine located in the north of Hokkaido, Japan. The mechanisms of long-term tailings weathering were assessed through leaching of hazardous metals by three column experiments. Measurements of mineralogical and chemical constituents, observation by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), sequential extraction of the tailings, and chemical analyses of the leachates were carried out to determine the processes responsible for the leaching of Cu, Zn, Fe, and sulfate ion (SO 4 2−). The contents of Cu, Zn, and Fe in the tailings were mainly associated with ion exchangeable and sulfide fractions. The pH values of the effluents from the columns were 3.0–3.7 throughout the experiments over 84 weeks, and approximately 15–23% of Cu, 35–45% of Zn, 2.5–4% of Fe and 15–20% of S were leached. Higher concentrations of Cu, Zn, Fe, and SO 4 2− at the beginning of the experiments were observed, which could be attributed to the dissolution of soluble sulfate minerals present in the tailings. This indicates that the formation and dissolution of secondary soluble sulfate minerals contributed to Cu and Zn leaching. The continuous leaching of Cu, Zn, Fe, and SO 4 2− suggests the oxidation of pyrite and other sulfide minerals. During these processes, ferrihydrite, goethite, lepidocrocite, and maghemite were formed and these minerals also acted as a sink for Cu and Zn by adsorption, and/or co-precipitation. These results mean the significance of the long-term behavior of hazardous metals released from mine tailings dams, which could provide helpful information on the management of tailings dams after mine closure. Highlights • Released metals corresponded to exchangeable fraction/soluble salts and subsequent continuous oxidation of sulfide fraction. • Zinc was more mobilized than Cu and Fe in the tailings. • Factors affecting pyrite oxidation were dissolved oxygen presented in distilled water, atmospheric oxygen and ferric iron. • The precipitation of secondary minerals (Fe-oxyhydroxides) was observed. • The acid mine drainage containing hazardous metals was expected to be released for a long period of time. [ABSTRACT FROM AUTHOR]

Highlights • Corrosion phenomena of PEO-treated films formed in solution containing Mn, Mg, and Si ions were studied. • In PEO-treated surface in electrolyte containing Mn ions, Mn precipitates were mainly formed on around the pore. • Number of pores on the PEO-treated surfaced decreased, as Mn contents increased. • Corrosion potential of PEO-treated surface in Mn ion solution was higher than that of in solution containing Mg ion. • From the AC impedance test, in the case of 5Mg5Mn/5Si specimen, polarization resistance is higher than those of others. Abstract In this study, corrosion phenomena of PEO-treated films formed in solution containing Mn, Mg, and Si ions were researched using various experimental instruments. Ti-6Al-4V ELI disk (grade 5, Timet Co. Ltd, Japan Diameter; 10 mm) was used as a specimen for plasma electrolytic oxidation (PEO) treatment. The specimen was cleaned and used as an anode, and a platinum rod was used as a cathode in the electrolyte containing Mn, Mg, and Si ions for PEO process. The potentiodynamic polarization and AC impedance tests for corrosion behaviors were carried out in 0.9% NaCl solution. The surfaces of the PEO-treated Ti-6Al–4V specimens were observed by a field emission scanning electron microscopy (FE-SEM, S-4800 Hitachi, Japan) and energy dispersive X-ray spectroscopy (EDS). In the case of PEO-treated surface in electrolyte containing Mn ions, precipitates of Mn were mainly formed on around the pore, and the number of pores decreased, as Mn contents increased. From the result of potentiodynamic test, the corrosion potential of PEO-treated surface in solution containing Mn ion was higher than that of in solution containing Mg ion. In the case of PEO-treated surface in electrolyte containing Mn ions, second anodic peaks showed in the passive region. From the AC impedance test, in the case of 5Mg5Mn/5Si specimen, polarization resistance is higher than those of other specimens. [ABSTRACT FROM AUTHOR]

Fragmentation of degraded plastics and release of smaller secondary microplastics is usually attributed to the growth of environmental stress cracks. Analysis of crack patterns derived from chemical degradation can be useful not only for assessing the cause of plastic fracture and evaluating the useful lifetime of a product, but it can also potentially provide valuable information on the generation of microplastics. However, the literature with respect to microplastics generation is generally limited to surface observations of polypropylene and polyethylene. Here, we used ion-beam milling to prepare cross-sections of fragments of 15 plastic products made from five commodity plastics (polypropylene, polyethylene, polystyrene, polyvinyl chloride, and polyethylene terephthalate) that were collected at two beaches in Japan, and then we examined the microstructures of those cross-sections by means of scanning electron microscopy and energy dispersive X-ray spectroscopy. Crack growth in the depth direction was examined to provide insights into microplastic generation behavior. In all of the polypropylene samples, and some of the low-density polyethylene and polystyrene samples, cracks with a depth exceeding 100 μm from the sample surface were observed. Considering that crack growth causes fracture of degraded plastic and microplastic release, these observations suggest the release of sharp-edged microplastics from the crack fracture surface. In contrast, in the high-density polyethylene and polyvinyl chloride samples, crack growth was limited to within 20 μm of the sample surface, suggesting the release of irregularly shaped microplastics and additive particles. The present results suggest that the degradation behavior of plastic products in the depth direction is dependent on the type of plastic. • Cross-sectional microstructural analysis of marine macroplastics was conducted. • Crack growth of five commodity plastics in the depth direction was evaluated. • Polypropylene samples showed crack growth to a depth of more than 100 μm. • High-density polyethylene and polyvinyl chloride showed additive release. • Crack growth patterns are highly dependent on the type of plastic. [ABSTRACT FROM AUTHOR]

The relation between concentration of elements and microbial activity in the water samples of Higashi-Hiroshima Campus, Hiroshima University was investigated. Energy dispersive X-ray spectroscopy revealed that microbial mat contains iron, aluminium, silicon and phosphorus. Model experiment revealed that the potassium was adsorbed by living microorganism in the microbial mats, while it was not adsorbed by dead microbial mat. Iron was adsorbed by both living and dead microbial mats. The present results explain the increase in the total b-radioactivity of water sample in summer and the decrease in winte. [ABSTRACT FROM AUTHOR]

Particular batches of Moderna mRNA Coronavirus Disease 2019 (COVID-19) vaccine were recalled after foreign particles were found in some vaccine vials at the vaccination site in Japan in August 2021. We investigated the foreign particles at the request of the Ministry of Health, Labour and Welfare. Energy dispersive X-ray spectroscopy analysis suggested that the foreign particles found in the vials recalled from the vaccination sites were from stainless steel SUS 316L, which was in line with the findings of the root cause investigation by the manufacturer. The sizes of the observed particles ranged from <50 μm to 548 μm in the major axis. Similar foreign particles were also detected in 2 of the 5 vaccine vials of the same lot stored by the manufacturer, indicating that the foreign particles have already been administered to some people via vaccine. Observation of the vials of the same lot by digital microscope found smaller particles those were not detected by visual inspection, suggesting that more vials were affected. Contrarily, visual inspection and subvisible particulate matter test indicated no foreign particles in the vials of normal lots. Possible root cause and strategies to prevent such a deviation were discussed from technical and regulatory aspects.

• Solidified products of molten SUS-B 4 C mixture were systematically characterized. • γ-Fe and (Cr,Fe) 2 B are the solidified phases when the B 4 C content is below 3 mass%. • (Cr,Fe) 23 (C,B) 6 is additionally solidified when the B 4 C content exceeds 3 mass%. • Solidification and re-melting of molten/solidified SUS-B 4 C mixture are eutectic. Fundamental understanding of the high-temperature interaction between stainless steel (SUS) and B 4 C is indispensable for estimating and characterizing the fuel debris generated during severe accidents of boiling water reactors (BWR), such as Fukushima Dai-ichi Nuclear Power Station (FDNPS, also referred to as "1F") in Japan. This study aims at systematically characterizing the solidified products of molten SUS-B 4 C mixtures by powder X-ray diffraction (PXRD), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), and thermogravimetry-differential thermal analysis (TG-DTA) with a range of the B 4 C content relevant to the fuel debris composition expected at 1F, in order to elucidate the solidification and re-melting mechanisms. The results indicated that γ-Fe and (Cr,Fe) 2 B are the major solidified phases when the B 4 C content is below 3 mass%, while (Cr,Fe) 23 (C,B) 6 is formed as an additional third phase when the B 4 C content exceeds 3 mass%. The solidification of molten SUS-B 4 C mixture and re-melting of solidified SUS-B 4 C melt are eutectic, which is mainly controlled by the pseudo-binary Fe–B system that is influenced by the C and Cr content and additional minor components such as Mo. [ABSTRACT FROM AUTHOR]

As a candidate accident tolerant fuel cladding material, the high temperature oxidation behaviour of an Oxygen Dispersion Strengthened (ODS) Fe–12Cr–6Al alloy has been examined in isothermal air and steam environments. While the oxidation behaviour of FeCrAl has been extensively studied, very little has been reported in the literature on FeCrAl-ODS, which is the focus of this manuscript. By conducting Thermogravimetric Analysis (TGA), oxidation experiments were performed on specimens of Fe–12Cr–6Al-ODS at temperatures up to 1400 °C in air and up to 1215 °C in high purity steam. Oxidation kinetics were evaluated by calculating reaction rate constants and activation energies. The formation of an alumina scale was correlated to kinetics results from TGA by coupling Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS) line scans to investigate the chemical composition of the primary oxide layer, local oxidation effects, as well as the bulk alloy material. Electron Probe Micro-Analysis (EPMA) point scans were applied to the heavily oxidized specimen to achieve an accurate composition profiling of areas of interest. Finally, thermodynamic calculations were performed to interpret the formation of the complex oxide layer. These experiments support research efforts for the development of accident tolerant fuel technologies at Nippon Nuclear Fuel Development Co., Ltd. [ABSTRACT FROM AUTHOR]

• The cadmium hepatotoxicity is characterized by transmission electron microscopy and X-ray energy dispersive spectroscopy. • Cadmium can be detected at microscale for ultrathin sections of cadmium treated liver tissue of rats. • Cadmium indeed leads to mitochondrial damage from the perspective of analytical transmission electron microscopy. The threat of cadmium (Cd), which is the cause of itai-itai disease in Japan, is still complicated and confusing, especially for digestive system, such as liver disease. One of the most keys of this problem is demonstrating that the hepatotoxicity is indeed induced by Cd. Therefore, we attempt detecting Cd at microscale during ultrastructural imaging of liver tissue. 12 rats were divided randomly into two experimental groups: control and Cd-treated. Treated rats were intraperitoneal injected with 1 mg/kg body weight cadmium chloride (CdCl 2) for 4 weeks (5 P.M each day for 6 days/week). At the end of the exposure period, liver tissue samples were processed into ultrathin sections for analysis of advanced analytical transmission electron microscopy and X-ray energy dispersive spectroscopy (TEM/X-EDS) investigations. Ultrastructural images and X-ray energy dispersive spectrum were acquired at microscale. Cd can cause changes in the structure of the organelle, including the collapse of the membrane structure in the cell, the destruction of the internal structure of the organelle, the mitochondrial swelling, the expansion of the endoplasmic reticulum, and the appearance of inclusions. Cadmium bioaccumulation is detected in the mitochondria at microscale by TEM/X-EDS, which is the visual evidence of morphological changes of mitochondria related to Cd. The combination of detailed ultrastructure and microscale X-ray energy dispersive spectroscopy (X-EDS) characterization of cadmium hepatotoxicity demonstrate that cadmium indeed leads to mitochondrial damage, which is helpful for further investigation of the pathological mechanism of cadmium hepatotoxicity. [ABSTRACT FROM AUTHOR]

A new method, namely, force–distance curve mapping, was developed to directly measure the adhesion force of individual aerosol particles by atomic force microscopy. The proposed method collects adhesion force from multiple points on a single particle. It also takes into account the spatial distribution of the adhesion force affected by topography (e.g., the variation in the tip angle relative to the surface, as well as the force imposed upon contact), thereby enabling the direct and quantitative measurement of the adhesion force representing each particle. The topographic effect was first evaluated by measuring Polystyrene latex (PSL) standard particles, and the optimized method was then applied on atmospherically relevant model dust particles (quartz, ATD, and CJ-1) and inorganic particles (ammonium sulfate and artificial sea salt) to inter-compare the adhesion forces among different aerosol types. The method was further applied on the actual ambient aerosol particles collected on the western coast of Japan, when the region was under the influence of Asian dust plume. The ambient particles were classified into sea salt (SS), silicate dust, and Ca-rich dust particles based on individual particle analysis (micro-Raman or Scanning Electron Microscope/Energy Dispersive X-ray Spectroscopy (SEM-EDX)). Comparable adhesion forces were obtained from the model and ambient particles for both SS and silicate dust. Although dust particles tended to show smaller adhesion forces, the adhesion force of Ca-rich dust particles was larger than the majority of silicate dust particles and was comparable with the inorganic salt particles. These results highlight that the original chemical composition, as well as the aging process in the atmosphere, can create significant variation in the adhesion force among individual particles. This study demonstrates that force–distance curve mapping can be used as a new tool to quantitatively characterize the physical properties of aerosol particles on an individual basis. [ABSTRACT FROM AUTHOR]