Search

Neutron Diffraction represents the ideal technique for the characterisation of the micro-structural properties of ancient metals, allowing retrieval of information on the smelting process, and the mechanical and thermal treatments applied during the manufacture of the sample. The object under investigation is a 17th century Japanese helmet (kabuto) from the Haruta School that has already been analysed, along with other six similar examples, using a general purpose neutron diffractometer. Through this study, the quality of the steel (phase composition) was determined and information on the thermo-mechanical treatments applied was inferred, averaging over a scattering volume that affected the entire thickness of the sample. The Haruta kabuto stood out for its very high carbon content, the absence of texture and residual strain, and very big grain size. These factors and the presence of incomplete reduction of the ore sand suggest the presence of plates with a composite structure of layers of steel and iron superimposed. This paper shows the possibility of using neutron diffraction on a highly collimated instrument, such as ENGIN-X (ISIS, UK), to be able to select a very small gauge volume and, this way, to detect variations in the phase composition along the thickness of the plates. Here we present novel results from diffraction measurements by using the instrument ENGIN-X. This study completes the previous cycle of neutron measurements on this sample and sheds light on the structure of the plates. [ABSTRACT FROM AUTHOR]

We present a workflow to non-destructively determine the elemental compositions of internal volumes of interest enclosed within complex-shaped objects, by combining 3D X-ray or neutron imaging, prompt-gamma activation analysis, and advanced Monte Carlo computer simulations. The correction of neutron- and gamma-attenuation effects during elemental analysis made it possible for the first time to obtain quantitative elemental compositions for such geometries. We applied the method successfully to an articulated iron lobster artifact from Japan's Edo period. Using synchrotron X-ray and neutron imaging, we revealed that it has been constructed from numerous hammered plates. Rivets and two kinds of solder materials were identified based on the contrasts observed in the XCT images; these were selected for local composition analysis. It was found that one soldering material consisted of Cu63Zn37 brass, while the other was composed of a eutectic tin and lead alloy Sn39Pb61. The Zn/Cu adhesive is widely used to bond small areas, whereas the Sn/Pb adhesive is used for attaching larger surfaces. [ABSTRACT FROM AUTHOR]

The oral administration of clioquinol – a potent 8-hydroxyquinoline antimicrobial drug – was forbidden due to suspicion of it being the cause of SMON (subacute myelo-optic-neuropathy) in Japan. However, this adverse effect was only observed in Japan, despite the fact that the drug was used worldwide. In addition, studies have shown that vitamin B12 deficiency could be involved in this process. Thus, the interest in the modification of this compound has recently emerged as a strategy to find new drug candidates. In the present work, we have designed and synthesized a novel series of clioquinol derivatives by the modification of the 7-position of this compound. Twenty-one derivatives were prepared from commercially available clioquinol in two or three steps: 8-OH-protection of clioquinol followed by the palladium-catalyzed cross-coupling reaction to introduce the arylamine group at position 7 resulting in derivatives 4a–4j. Finally, deprotection of the hydroxyl group gave derivatives 5a–5i and 10a–10b. The compounds prepared were tested against Candida spp. and dermatophyte isolates by the broth microdilution method. We have found a clear structure–activity relationship. The presence of free hydroxyl in the 8-position and the introduction of the hydrophilic heterocyclic substituent at the 7-position are important for the antifungal activity of this class. Moreover, the introduction of dimethoxy groups at the pyrimidinyl ring attached to the 7-position seems to be promising against dermatophytes and Candida albicans. Among all derivatives, compound 5h presented interesting activity against all fungal species tested (with MIC values of 4 μg mL−1), along with low toxicity in normal cells. This derivative is non-irritant with the absence of topical toxicity. In addition, 5h does not seem to act as an ionophore in fungal cells, similarly to clioquinol. These compounds appear to have a scavenger effect, which suggests their selectivity for fungal cells. Taken together, these findings indicate the potential of 5h to be developed as an antifungal agent. [ABSTRACT FROM AUTHOR]

A simple, fast and sensitive analytical method for iodine speciation in seawater by multi-mode size exclusion chromatography coupled with sector-field inductively coupled mass spectrometry (HPLC-SF-ICP-MS) is described in this paper. Total iodine concentration was directly measured using SF-ICP-MS after 100-fold dilution with 1% TMAH. Separation of iodate and iodide was achieved using an AsahiPak GS-220 multi-mode size exclusion column with a mobile phase of 50 mM malonic acid–37.5 mM TMAH (pH 6.9) with isocratic elution at a flow rate of 1.0 ml min−1. The detection limit was 0.00016 μM (20 ng l−1) for iodate and 0.00024 μM (30 ng l−1) for iodide, and they were ca. 70 times lower than those of the HPLC-ICP-QMS technique. The proposed method was successfully applied to the determination of iodate and iodide in seawaters from the surface down to a depth of 700 m collected from the Pacific Ocean off Aomori Prefecture, Japan. Vertical distributions of total iodine, iodate, iodide, total inorganic iodine and dissolved organic iodine were obtained using the developed method. Iodate was found to be the predominant species. This is the first report on the study of vertical distributions of iodine in seawater using the HPLC-ICP-MS technique. [ABSTRACT FROM AUTHOR]

In this work we present an extensive time of flight neutron diffraction (ToF-ND) study on some Japanese armour components. The experiments were carried out at the INES diffractometer at ISIS, the pulsed neutron source in the UK. In particular, we have studied seven Japanese helmets (kabuto) made between the 16th and 17th century. By means of this non-invasive approach we have been able to determine quantitatively the phase composition and the microstructural properties of these artefacts. The samples belong to different periods and different levels of quality. The observed differences were quantified in terms of the accuracy and amount of their working. A quantitative determination of their phases and of the thermo-mechanical treatments has been obtained for all investigated samples, confirming that the use of ToF-ND represents one of the most suitable non-destructive approaches for the characterization of metal archaeological artefacts. [ABSTRACT FROM AUTHOR]

Rapid preparation of p-tert-butylcalix[4]arene using microwave irradiation was studied and p-tert-butylcalix[4]arene was obtained as a pure form in modest yield with shortening the reaction time from hours to minutes. [ABSTRACT FROM AUTHOR]

Anthropogenic emissions in Asia have significantly increased during the last two decades; as a result, the induced air pollution and its influences on radiative forcing and public health are becoming increasingly prominent. The Aerodyne Aerosol Mass Spectrometer (AMS) has been widely deployed in Asia for real-time characterization of aerosol chemistry. In this paper, we review the AMS measurements in Asia, mainly in China, Korea, Japan, and India since 2001 and summarize the key results and findings. The mass concentrations of non-refractory submicron aerosol species (NR-PM 1 ) showed large spatial distributions with high mass loadings occurring in India and north and northwest China (60.2-81.3 μg m -3 ), whereas much lower values were observed in Korea, Japan, Singapore and regional background sites (7.5-15.1 μg m -3 ). Aerosol composition varied largely in different regions, but was overall dominated by organic aerosols (OA, 32-75%), especially in south and southeast Asia due to the impact of biomass burning. While sulfate and nitrate showed comparable contributions in urban and suburban regions in north China, sulfate dominated inorganic aerosols in south China, Japan and regional background sites. Positive matrix factorization analysis identified multiple OA factors from different sources and processes in different atmospheric environments, e.g., biomass burning OA in south and southeast Asia and agricultural seasons in China, cooking OA in urban areas, and coal combustion in north China. However, secondary OA (SOA) was a ubiquitous and dominant aerosol component in all regions, accounting for 43-78% of OA. The formation of different SOA subtypes associated with photochemical production or aqueous-phase/fog processing was widely investigated. The roles of primary emissions, secondary production, regional transport, and meteorology on severe haze episodes, and different chemical responses of primary and secondary aerosol species to source emission changes and meteorology were also demonstrated. Finally, future prospects of AMS studies on long-term and aircraft measurements, water-soluble OA, the link of OA volatility, oxidation levels, and phase state were discussed.

Since the accident at Fukushima Daiichi Nuclear Power Plant (1FNPP), significant levels of anthropogenic radionuclides have been detected in seabed sediments off the east coast of Japan. In this paper, the approximate amount of accident-derived radiocesium in seabed sediments off Fukushima, Miyagi and Ibaraki prefectures was estimated from a sediment integration algorithm. As of October 2011, about half a year after the accident, the total amount of sedimentary 134Cs was 0.20±0.06 PBq (decay corrected to March 11, 2011) and more than 90% of the radiocesium was accumulated in the regions shallower than 200 m depth. The large inventory in the coastal sediments was attributed to effective adsorption of dissolved radiocesium onto suspended particles and directly to sediments in the early post-accident stage. Although rivers are also an important source to supply radiocesium to the coastal regions, this flux was much lower than that of the above-mentioned process within half a year after the accident.

A 85Kr measurement system for continuous monitoring based principally on the BfS-IAR method (activity measurement of 85Kr by gas counting coupled with gas chromatographic separation, using pure CH4 as carrier and Counting gas) was implemented for the first time in Japan. In this paper, a detailed description of the system and procedures is given and the inter-comparison results of our system with the BfS-IAR system are presented. A consistent temporal concentration change with high accuracy and consistency of the respective data with the BfS-IAR data (maximum difference of 5%) were achieved with the Meteorological Research Institute (MRI) system, which shows that the system is valid and reliable for the purpose of background monitoring for 85Kr in air. Also, the 85Kr monitoring record at the MRI during 1995-2001 is described. The record distinctively shows the Northern Hemispheric background 85Kr concentrations at the mid-latitude and the elevated concentrations affected by the operation of a nuclear fuel reprocessing plant in Tokai-mura, Ibaraki. Japan.