Speciation of iodine in solid environmental samples by iodine K-edge XANES: application to soils and ferromanganese oxides

A method was developed for speciation of iodine in solid materials using X-ray absorption near-edge structure (XANES). This method was used to identify the iodine species (mainly inorganic iodine) in environmental samples. It was shown that the XANES spectra of iodide and iodate sorbed within solid materials can be simulated by the linear combination of the spectra of iodide and iodate ions in water. The distribution coefficient (Kd) between soil and water was obtained independently for iodide and iodate, based on iodine speciation both in the solid phase, by XANES, and in the aqueous phase, by HPLC-ICP-MS. It was found that the Kd of iodate is larger than that of iodide by a factor of more than six, showing the more soluble nature of iodide. It was suggested that iodate can form in soil even when iodide is injected into the soil-water system under conditions within the iodide-stable field of the Eh-pH diagram of iodine. This is caused by the much higher affinity of iodate for solid surfaces than iodide. In soil samples under various water saturation conditions, or various Eh conditions, the iodide fraction in water increases with decreasing Eh, which results in an increase in the dissolved total iodine fraction in soil water. The speciation method using XANES was also applied to iodine in a natural soil sample and marine ferromanganese oxides. It is suggested that iodine K-edge XANES is a promising tool for determining the iodide/iodate ratio in natural solid samples, which contributes to better understanding of the behavior of iodine at the Earth's surface.     

Adenoid cystic carcinoma of the external auditory canal: correlation between histological features and MRI appearances

A rare case of adenoid cystic carcinoma of the external auditory canal with magnetic resonance imaging appearances is reported. Both T1 weighted and T2 weighted MR images showed the tumour as a hypointense mass, although there was marked contrast enhancement. Microscopic examination of the resected tumour showed a preponderance of solid tumour cell nests. According to previous reports, these pathological and radiological findings indicate a poor prognosis.     

Calcium Silicate Carbonation Products

calcium silicates such as C₃S, βT-C₂S, and γgM-C₂S ^† were carbonated under saturated humidity at room temperature. Carbonation products were examined by DT-TGA, gasphase mass spectroscopy, and XRD. Two types of carbonate were produced: one type, which was rather poorly crystallized, was decarbonated at a very low temperature, below 600°C; the other type was a crystalline phase such as calcite, aragonite, and/or vaterite which was decarbonated above 600°C. The data were compared to existing data for calcium carbonates and basic calcium carbonates. The results suggest that an amorphous calcium silicate hydrocarbonate was one of the carbonation products which formed during the hydration/carbonation reaction.     

Template‐Assisted Synthesis of Metallic 1T′‐Sn0.3W0.7S2 Nanosheets for Hydrogen Evolution Reaction

Crystal phase control still remains a challenge for the precise synthesis of 2D layered metal dichalcogenide (LMD) materials. The T′ phase structure has profound influences on enhancing electrical conductivity, increasing active sites, and improving intrinsic catalytic activity, which are urgently needed for enhancing hydrogen evolution reaction (HER) activity. Theoretical calculations suggest that metastable T′ phase 2D Sn_1?xW_xS₂ alloys can be formed by combining W with 1T tin disulfide (SnS₂) as a template to achieve a semiconductor‐to‐metallic transition. Herein, 2D Sn_1?xW_xS₂ alloys with varying x are prepared by adjusting the molar ratio of reactants via hydrothermal synthesis, among which Sn_0.3W_0.7S₂ displays a maximum of concentration of 81% in the metallic phase and features a distorted octahedral‐coordinated metastable 1T′ phase structure. The obtained 1T′‐Sn_0.3W_0.7S₂ has high intrinsic electrical conductivity, lattice distortion, and defects, showing a prominently improved HER catalytic performance. Metallic Sn_0.3W_0.7S₂ coupled with carbon black exhibits at least a 215‐fold improvement compared to pristine SnS₂. It has excellent long‐term durability and HER activity. This work reveals a general phase transition strategy by using T phase materials as templates and merging heteroatoms to achieve synthetic metastable phase 2D LMDs that have a significantly improved HER catalytic performance.     

A facsimile-based graphics editing system by auxiliary mark recognition

This paper describes a facsimile-based graphics editing system using handwritten mark recognition, and presents some experimental results with the system. In a manner different from usual graphics editors based on CRT displays and data tablets, only facsimiles are used as input and output devices in this system. As the first stage in processing, a graphic subject is first given as a set of line drawings and characters handwritten on a sheet of paper, and it is then input into the computer as a binary picture from a facsimile transmitter. Auxiliary editing information is input into the computer as handwritten marks or seal marks prepared on a separate sheet of paper. As the second stage, the marks are recognized and used to create a mark parameter list for the graphics editing. Third, referencing the mark parameter list, the graphics are expressed by using a set of graphic commands, and edited by the computer. Finally, a correct edited copy of the graphics is constructed by picture processing based on graphic commands, and it is output to a facsimile receiver. Very good results have been obtained for various kinds of hand-written graphics by using the system described here.     

Purification of steryl esters from soybean oil deodorizer distillate

Soybean oil deodorizer distillate (SODD) contains steryl esters in addition to tocopherols and sterols. Tocopherols and sterols have been industrially purified from SODD but no purification process for steryl esters has been developed. SODD was efficiently separated to low b.p. substances (including tocopherols and sterols) and high b.p. substances (including 11.2 wt% DAG, 32.1 wt% TAG, and 45.4 wt% steryl esters) by molecular distillation. The high b.p. fraction is referred to as soybean oil deodorizer distillate steryl ester concentrate (SODDSEC). We attempted to purify steryl esters after a lipase-catalyzed hydrolysis of acylglycerols in SODDSEC. Screening of industrially available lipases indicated that Candida rugosa lipase was most effective. Based on the study of several factors affecting hydrolysis, the reaction conditions were determined as follows: ratio of SODDSEC/water, 1∶1 (w/w); lipase amount, 15 U/g reaction mixture; temperature, 30°C. When SODDSEC was agitated for 24 h under these conditions, acylglycerols were almost completely hydrolyzed and the content of steryl esters did not change. However, study with a mixture of steryl oleate/trilinolein (1∶1, w/w) indicated that about 20% of constituent FA in steryl esters were exchanged with constituent FA in acylglycerols. Steryl esters in the oil layer obtained by the SODDSEC treatment with lipase were successfully purified by molecular distillation (purity, 97.3%; recovery, 87.7%).