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This paper addresses clinical research on moral education lessons to enhance the self-affirmative consciousness of students in Japan and Taiwan. We conducted four lessons for fifth and sixth graders under the same conditions. The lesson was about the natural environment and was organized as a cooperative learning experience. The Association Method was employed as an assessment. Prompted by the image of , response words such as “water,” “air,” and “environment” appeared in four classes after the lesson. Through the 60-minute lesson, more than half of the response words changed. This indicates that the children concentrated deeply on the lesson, and that it made an impression on them. The results from the Japanese A and B and Taiwanese C and D schools were diverse. We compared the response words before andafter the lesson, using the Association Method by cue word , which shows self-affirmative consciousness. In class A, words that recognize the importance of nature appeared even in self-consciousness, and in class B, positive words increased and negative words decreased significantly (p < .05). In class C, consciousness of “oneself” and “family” increased, and in class D, “life” and “friend” increased. We interpreted these differences as a result of the children’s reflections on their own inner character and the historical background they have learned and not learned.

While chrysotile has been commonly used by Chinese textile industry for many years, investigations on the association of chrysotile exposure with risk of mesothelioma in China are scarce. We conducted a case-control study in a county located at Southeastern China, including 46 cases and 230 individually matched controls. A semi-quantitative method based on experts' assessment was used for evaluating hand-spinning chrysotile exposure. Conditional logistic regression models were used to assess the association of asbestos exposure with risk of mesothelioma. We found that hand-spinning chrysotile exposure was associated with significantly elevated risk of mesothelioma, reaching OR =10 (95% CIs: 1.4-65) for possible exposure and 64 (12-328) for definite exposure. Our data suggested a dose-response relationship of chrysotile exposure duration with risk of mesothelioma, reaching 28 (6-134) for 28.6 f/mL-years. We found a dose-response relationship of chrysotile exposure duration and CEI with risk of mesothelioma in Southeastern China, adding valuable information on health hazards of chrysotile exposure in China where chrysotile is still used nationwide.

To address various fisheries science problems around Japan, the Japan Fisheries Research and Education Agency (FRA) has developed an ocean forecast system by combining an ocean circulation model based on the Regional Ocean Modeling System (ROMS) with three-dimensional variational analysis schemes. This system, which is called FRA-ROMS, is a basic and essential tool for the systematic conduct of fisheries science. The main aim of FRA-ROMS is to realistically simulate mesoscale variations over the Kuroshio-Oyashio region. Here, in situ oceanographic and satellite data were assimilated into FRA-ROMS using a weekly time window. We first examined the reproducibility through comparison with several oceanographic datasets with an Eulerian reference frame. FRA-ROMS was able to reproduce representative features of mesoscale variations such as the position of the Kuroshio path, variability of the Kuroshio Extension, and southward intrusions of the Oyashio. Second, using a Lagrangian reference frame, we estimated position errors between ocean drifters and particles passively transported by simulated currents, because particle tracking is an essential technique used in applications of reanalysis products to fisheries science. Finally, we summarize recent and ongoing fisheries studies that use FRA-ROMS and mention several new developments and enhancements that will be implemented in the near future.

Background To determine whether the HRCT findings are useful to differentiate asbestosis from idiopathic pulmonary fibrosis (IPF). Methods We assessed HRCT scans from patients with asbestosis (n = 96) and IPF (n = 65). The frequencies and extent of parenchymal abnormalities and the frequencies of pleural changes were evaluated by consensus of two chest radiologists. Results There was a significant difference between IPF and asbestosis in pleural changes. In addition, there were significant differences between IPF and asbestosis in several parenchymal abnormalities on CT, especially in the less advanced stage of both diseases. On multivariate analysis, HRCT features that distinguished asbestosis from IPF were subpleural lines at a distance of less than 5 mm from the inner chest wall, subpleural dots and parenchymal bands. Conclusions There are significant differences between IPF and asbestosis in the parenchymal and pleural abnormalities on CT. Am. J. Ind. Med. 59:301–306, 2016. © 2016 Wiley Periodicals, Inc.

Background Chrysotile had been used in asbestos textile workshops in Southeast China but a clear relation to mesothelioma is lacking. Methods All patients diagnosed with mesothelioma from 2003 to 2010 at Yuyao People’s Hospital were re-evaluated by multiple expert pathologists with immunohistochemistry and asbestos exposure data were collected. Results Of 43 patients with a mesothelioma diagnosis, 19 peritoneal and nine pleural cases were finally diagnosed as mesothelioma. All were females, and the mean age of the patients with peritoneal or pleural mesothelioma was 52.4 and 58.2 years, respectively. All these cases had a history of domestic or occupational exposure to chrysotile. Twothirds of the patients were from two adjoining towns with multiple small asbestos textile workshops. Contamination of tremolite was estimated to be less than 0.3%. Conclusions This is a report of mesothelioma in women exposed to chrysotile asbestos at home and at work, with an over-representation of peritoneal mesothelioma. Am. J. Ind. Med. © 2015 Wiley Periodicals, Inc.

Background The aim of this study was to elucidate whether there is a relationship between the extent of pleural plaques and pulmonary asbestos body concentration (PABC). Methods The subjects were 207 lung cancer patients with occupational asbestos exposure. We determined the plaque extent by findings on chest images using our own criteria. PABCs were measured in resected or autopsy lung specimens. Results There was a significant relationship between plaque extent and PABC. Seventy-five percent of the patients determined to have extensive plaques based on our criteria had a PABC of ≥5,000 asbestos bodies per gram of dry lung tissue, which is one of the certification criteria of lung cancer caused by asbestos for workers' compensation in Japan. Conclusions In lung cancer patients, the plaque extent had a significant positive relationship with the PABC. The plaque extent would be useful as a proxy for PABC for lung cancer compensation purposes. Am. J. Ind. Med. 58:444–455, 2015. © 2015 Wiley Periodicals, Inc.

The carcinogenicity of short tremolite fibers in human has not been cleared and has been argued hitherto. A lung cancer patient had worked at a gabbro quarry. Particles isolated from the excised lung parenchyma of the patient were measured for asbestos bodies (ABs) and asbestos fibers (AFs). The concentrations of ABs were 3964 AB/g dry lung, and AFs were 5.60 × 106 fibers/g dry lung (>5 um in length) and 22.5 × 106 fibers/g dry lung (>1 um in length). AFs were mostly tremolite fibers and under 7 um in length (mean length 4.0 um, standard deviation 2.8 um). Almost all fibers were

While chrysotile has been commonly used by Chinese textile industry for many years, investigations on the association of chrysotile exposure with risk of mesothelioma in China are scarce. We conducted a case-control study in a county located at Southeastern China, including 46 cases and 230 individually matched controls. A semi-quantitative method based on experts' assessment was used for evaluating hand-spinning chrysotile exposure. Conditional logistic regression models were used to assess the association of asbestos exposure with risk of mesothelioma. We found that hand-spinning chrysotile exposure was associated with significantly elevated risk of mesothelioma, reaching OR =10 (95% CIs: 1.4-65) for possible exposure and 64 (12-328) for definite exposure. Our data suggested a dose-response relationship of chrysotile exposure duration with risk of mesothelioma, reaching 28 (6-134) for6 years, 51 (11-247) for 7-17 years and 56 (9-351) for ≥18 years. A dose-response relationship of cumulative exposure index (CEI) with risk of mesothelioma was found, reaching 28 (6-137) for CEI at 0-0.5 fibers per milliliter years (f/mL-year), 36 (7-184) for CEI at 0.5-28.6 f/mL-years and 79 (14-451) for CEI 28.6 f/mL-years. We found a dose-response relationship of chrysotile exposure duration and CEI with risk of mesothelioma in Southeastern China, adding valuable information on health hazards of chrysotile exposure in China where chrysotile is still used nationwide.

To determine whether the HRCT findings are useful to differentiate asbestosis from idiopathic pulmonary fibrosis (IPF).We assessed HRCT scans from patients with asbestosis (n = 96) and IPF (n = 65). The frequencies and extent of parenchymal abnormalities and the frequencies of pleural changes were evaluated by consensus of two chest radiologists.There was a significant difference between IPF and asbestosis in pleural changes. In addition, there were significant differences between IPF and asbestosis in several parenchymal abnormalities on CT, especially in the less advanced stage of both diseases. On multivariate analysis, HRCT features that distinguished asbestosis from IPF were subpleural lines at a distance of less than 5 mm from the inner chest wall, subpleural dots and parenchymal bands.There are significant differences between IPF and asbestosis in the parenchymal and pleural abnormalities on CT.

Previous studies reported that exposure to dioxins was associated with an increased risk of various diseases in general populations. The aim of this study was to examine the association between levels of dioxins in blood and allergic and other diseases. We conducted a cross-sectional study on 1,063 men and 1,201 women (aged 15–76 years), who were living throughout Japan and not occupationally exposed to dioxins, during 2002–2010. In fasting blood samples, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like PCBs (DL-PCBs) were analyzed by isotope dilution high-resolution gas chromatography/mass spectrometry. We obtained information on life style and self-reported history of diseases using a questionnaire. Blood pressure, blood levels of hemoglobin A1c, and serum lipids were also measured. Multiple logistic regression models were used to analyze the association between dioxin levels in blood and various diseases. Toxic equivalents of PCDDs/PCDFs and total dioxins showed significant inverse dose–response relationships with atopic dermatitis, after adjustments for potential confounders. The highest quartile for total dioxins had an adjusted odds ratio of 0.26 (95 % confidence interval 0.08–0.70) compared to the reference group (first quartile). The odds ratios for hypertension, diabetes mellitus, hyperlipidemia, gout in men, and gynecologic diseases in women significantly increased with increasing toxic equivalents of PCDDs/PCDFs, DL-PCBs, and total dioxins in blood. The present findings suggest that background exposure to dioxins was associated with reduced risk of atopic dermatitis. The results also support the idea that low-level exposure to dioxins is associated with an increased risk of diabetes, hypertension, and hyperlipidemia.

The purpose of the present study was to investigate the factors associated with blood levels of each congener of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) in the Japanese population.A cross-sectional study was performed on 1,656 subjects (755 men and 901 women) aged 15-73 years, who were living in 90 different areas of 30 prefectures in Japan. Blood levels of 29 PCDD, PCDF, and DL-PCB congeners were determined by high-resolution gas chromatography/mass spectrometry. In addition, a questionnaire survey on life style, including dietary habit, was carried out.The median total toxicity equivalent (TEQ) was 17 pgTEQ/g lipid. After adjustment for age, sex, body mass index, smoking habit, and consumption of other food groups, six PCDDs/PCDFs with 4-6 substituted chlorine atoms and 10 DL-PCBs, but not HeptaCDD/F or OctaCDD, showed significant positive correlations with the frequency of intake of fish and shellfish. Furthermore, significant positive relationships were also found between plasma levels of docosahexaenoic acid (DHA), a biomarker of fish intake, and 10 PCDDs/PCDFs with 4-6 chlorine atoms and 10 DL-PCBs. The partial correlation coefficients with plasma DHA were significantly higher for DL-PCBs than for PCDDs/PCDFs, and partial correlation coefficients for PCDDs/PCDFs significantly decreased with increasing number of chlorine atoms (Spearman r = -0.80, P = 0.001).Blood levels of PCDDs/PCDFs with 4-6 chlorine atoms and DL-PCBs were positively associated with fish intake in the Japanese population. These results may be explained by the higher degree of bioaccumulation of these congeners in fish and shellfish in the ecosystem, and the high consumption of fish among the Japanese population.

The annual distribution and dispersal of early‐stage phyllosoma of the Japanese spiny lobster Panulirus japonicus were examined in the East China Sea and the Sea of Japan off western Japan. Early‐stage larvae were sampled mainly in summer and relatively near the coast off western Kyusyu Island. Few larvae were found in the other three seasons in the East China Sea and the Sea of Japan. This finding suggests that P. japonicus larvae are retained in coastal areas for a few months after hatching until stage V and are transported offshore until autumn, before they grow to stage VI. Examination of archival drifter data off western Kyusyu Island during the spawning season of P. japonicus supported the relatively rapid dispersal of the larvae from the East China Sea near Japan to the Pacific Ocean or the Sea of Japan. Larval transport from the East China Sea to the Pacific Ocean, which is considered to be a main distribution area of middle‐ and late‐stage larvae, would occur in the south at approximatel...

Background Environmental exposure to some persistent organic pollutants has been reported to be associated with a metabolic syndrome in the U.S. population. Objectives We evaluated the associations of body burden levels of dioxins and related compounds with the prevalence of metabolic syndrome among the general population in Japan. Methods We conducted a cross-sectional study with 1,374 participants not occupationally exposed to these pollutants, living throughout Japan during 2002–2006. In fasting blood samples, we measured biochemical factors and determined lipid-adjusted concentrations of 10 polychlorinated dibenzo-p-dioxins (PCDDs), 7 polychlorinated dibenzofurans (PCDFs), and 12 dioxin-like poly-chlorinated biphenyls (DL-PCBs) all of which have toxic equivalency factors. We also performed a questionnaire survey. Results The toxic equivalents (TEQs) of PCDDs, PCDFs, and DL-PCBs and total TEQs had significant adjusted associations with metabolic syndrome, whether or not we excluded diabetic subjects. By analyzing each component of metabolic syndrome separately, the DL-PCB TEQs and total TEQs were associated with all components, and the odds ratios (ORs) in the highest quartile of DL-PCB TEQs in four of the five components were higher than those for PCDDs or PCDFs. We also found congener-specific associations with metabolic syndrome; in particular, the highest quartiles of PCB-126 and PCB-105 had adjusted ORs of 9.1 and 7.3, respectively. Conclusions These results suggest that body burden levels of dioxins and related compounds, particularly those of DL-PCBs, are associated with metabolic syndrome. Of the components, high blood pressure, elevated triglycerides, and glucose intolerance were most closely associated with these pollutants.

Objective The objective was to grasp the recent body burden levels of polychlorinated dibenzo- p -dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (DL-PCBs) and to investigate their determinants among general inhabitants in Japan. Methods This study was performed on 1374 participants aged 15–73 years, who were not occupational exposure to PCDDs/PCDFs and DL-PCBs, living widely in 75 different residential areas of 25 prefectures in Japan. Seven PCDDs, ten PCDFs, twelve DL-PCBs, which are assigned a toxicity equivalent factor, and biochemical factors were determined in fasting blood. A questionnaire survey on life-style was also performed. Results The median of total toxicity equivalent (TEQ) was 20 pg TEQ/g lipid. The TEQs of PCDDs/PCDFs, DL-PCBs and total TEQ increased with age. The intake frequency of fish-and-shellfish was positively associated with the TEQ of DL-PCBs in both sexes. Current smoking was negatively related to the TEQ of DL-PCBs in male subjects but not in female subjects. Feeding status was significantly related to the TEQs of PCDDs/PCDFs, DL-PCBs and total TEQ, being lowest in breast feeding and highest in never and bottle feeding. According to the results of subgroup analysis, parity was not associated with the TEQs. Conclusions The fish-and-shellfish consumption may contribute to the accumulation of DL-PCBs, and smoking may induce some biological action for the elimination of DL-PCBs from the human body. Breast feeding is considered to be one of the major excretory pathways of PCDDs/PCDFs and DL-PCBs in women, while parity may not largely contribute to the elimination of these pollutants.

OBJECTIVE. The purpose of this study was to evaluate the radiographic and CT findings of inhalational talc pneumoconiosis.CONCLUSION. Large opacities of talc pneumoconiosis progress more often than do small opacities. The CT findings of talc pneumoconiosis overlap those of silicosis and asbestosis.

Chrysotile had been used in asbestos textile workshops in Southeast China but a clear relation to mesothelioma is lacking.All patients diagnosed with mesothelioma from 2003 to 2010 at Yuyao People's Hospital were re-evaluated by multiple expert pathologists with immunohistochemistry and asbestos exposure data were collected.Of 43 patients with a mesothelioma diagnosis, 19 peritoneal and nine pleural cases were finally diagnosed as mesothelioma. All were females, and the mean age of the patients with peritoneal or pleural mesothelioma was 52.4 and 58.2 years, respectively. All these cases had a history of domestic or occupational exposure to chrysotile. Two-thirds of the patients were from two adjoining towns with multiple small asbestos textile workshops. Contamination of tremolite was estimated to be less than 0.3%.This is a report of mesothelioma in women exposed to chrysotile asbestos at home and at work, with an over-representation of peritoneal mesothelioma.

To clarify the level of contamination with radioactive cesium (radiocesium) discharged from Fukushima Dai-ichi Nuclear Power Plant (FDNPP), three fish species caught in the main harbor of FDNPP were subjected to γ-ray analysis. The concentration of radiocesium in muscle differed among individual fish, even those of similar size of the same species, and showed little relation to the standard length of fish. The maximum concentration of radiocesium (202 kBq/kg wet) was detected from fat greenling samples. A comparison to data from outside the port indicated that the level of radiocesium contamination inside the port was higher than that outside. We found that β-rays were emitted from otoliths of fishes caught in the port of FDNPP. β-ray intensities were correlated with the concentrations of radiocesium in muscles of the three fish species. In Japanese rockfish, the β-ray count rates from otoliths were significantly correlated with the concentration of radiocesium and (90)Sr in the whole body without internal organs of Japanese rockfish. However, no β-rays were detected from brown hakeling samples collected around FDNPP, suggesting that the detection of β-rays from otoliths may indicate living in the main harbor of FDNPP.

After the Fukushima Dai-ichi Nuclear Power Plant (FNPP) accident, which occurred in March of 2011, the National Research Institute of Fisheries Science (NRIFS) undertook emergent radioactivity monitoring of 63 samples of small epipelagic fishes (such as sardine and Japanese anchovy) collected by commercial fishery boats off the Kashima-Boso area (located to the south of the Fukushima coast) from 24 March 2011 to 21 March 2013. Fluctuations in the radiocesium concentration in fish muscles synchronized with the decreasing concentration from seawater near the fishing ground; the radiocesium concentration in fish muscles reached a maximum of 31 Bq/kg-wet in July 2011, after which it declined gradually. From 2012 to 2013, the radiocesium concentrations in fish muscles were low (0.58–0.63 Bq/kg-wet). Compared to the 137Cs concentration before the FNPP accident, 137Cs concentration in fish muscles in 2013 was still about 10 times higher, whereas it was about 4.5 times higher in seawater near the fishing ground in 2012.

The aim of this study was to elucidate whether there is a relationship between the extent of pleural plaques and pulmonary asbestos body concentration (PABC).The subjects were 207 lung cancer patients with occupational asbestos exposure. We determined the plaque extent by findings on chest images using our own criteria. PABCs were measured in resected or autopsy lung specimens.There was a significant relationship between plaque extent and PABC. Seventy-five percent of the patients determined to have extensive plaques based on our criteria had a PABC of ≥5,000 asbestos bodies per gram of dry lung tissue, which is one of the certification criteria of lung cancer caused by asbestos for workers' compensation in Japan.In lung cancer patients, the plaque extent had a significant positive relationship with the PABC. The plaque extent would be useful as a proxy for PABC for lung cancer compensation purposes.

The surface tensions of xPbO-(100−x) B2O3 (x = 30–80 mol%) and xBi2O3-(100−x) B2O3 (x = 0–100 mol%) melts were measured using the ring method over the temperature range 973 to 1373 K. The compositional and temperature dependences of surface tension were investigated. Addition of PbO and Bi2O3 to B2O3 increased the surface tensions of their respective PbO-B2O3 and Bi2O3-B2O3 melts. The surface tension showed a maximum at 60 mol% PbO in the PbO-B2O3 melts and at 70–80 mol% Bi2O3 in the Bi2O3-B2O3 melts. The temperature coefficient of surface tension was examined on the basis of its relationship to the structure, and it was suggested that the temperature coefficient of surface tension decreases with an increasing content of four-coordinated boron.

The integrated absorption cross section, the spontaneous emission probability, and the stimulated emission cross section of Yb3+ were determined in silicate, phosphate, borate, germanate, aluminate, gallate, and ZBLAN host glasses. The compositional dependence of the stimulated emission cross section of the 2F5/2→2F7/2 transition is determined mainly by the integrated absorption cross section in the glasses. A peak stimulated emission cross section above 1 pm2, which is the highest value in glasses, was obtained in a gallate glass with a composition of 40K2O·20Ta2O5. 40Ga2O3. The factors affecting the integrated absorption cross section are discussed using the Judd-Ofelt parameters of Er3+ calculated in previous studies.

Fluorescence spectra of Ce3+ ions in silicate, borate, and phosphate glasses melted in Ar were measured. The relative fluorescence intensity of Ce3+ in the ultraviolet region increased in the order of R = Ba, Ca, Sr, and Mg in the 20Li2O–20RO–60SiO2 glass samples and with decreasing BaO content in the BaO–B2O3 glass samples, respectively. In contrast, the relative fluorescence intensity of Ce3+ did not change with varying the glass composition in phosphate glass samples. The compositional dependence of the relative fluorescence intensity of Ce3+ is discussed in terms of redox reaction of Ce3+–Ce4+ in oxide glasses.

Interaction between 96% alumina and three binary glasses used as frits in thick-film technology is studied. A possible interfacial reaction mechanism where a melt glass penetrates into the alumina through the grain boundaries dissolving SiO2, one of the grain boundary components, is suggested. The formulation expressing the glass penetration rate into the alumina based on Poiseuilles law, assuming the driving force for the glass penetration is the capillary force, is consistent with the experimental growth rate of the reaction layer in the alumina. The formulation also clearly explains the relationship of the degree of glass penetration to the viscosity and the surface tension of the melt glass. The extraordinary difference in K, designated as the coefficient of penetration, between the calculated result and the experimental result suggests that the process of dissolving SiO2 into a melt glass at the alumina grain boundaries retards the glass penetration.

Point defects were found in as-quenched GeO2, 65CaO35Al2O3, and 65SrO35Ga2O3 glasses on the basis of electron paramagnetic resonance (EPR) measurements. These defects were identified as Ge E centers in GeO2 glass and O-2, O-3, and M-OHC (oxygen hole center) (where M = Al, Ga) in 65CaO35Al2O3 and 65SrO35Ga2O3 glasses. The formation of Ge E centers in as-quenched GeO2 glass was due to the thermodynamic stability of GeO at the melting temperature. The latter oxygen-excess defects are supposed to be formed by excess oxygen ions derived from the modifiers in the aluminate and gallate glasses during the formation of these glasses. To investigate some of the properties of the oxygen-excess defects in the calcium aluminate and strontium gallate glasses, chromium ions were doped in these glasses as a probe and the relationship between the valency state of the chromium ion and the defects was determined. We conclude that the peroxy bonding (-O-O-) oxidizes the Cr3+ species to Cr4+. Similar defects have been identified in host compounds that are used for Cr4+ tunable lasers. These results reveal that the point defects are necessary to stabilize the Cr4+ ions in glasses and crystals.

The Young's moduli of various oxide glasses (silicate, borate, phosphate, and tellurite) were measured using an ultrasonic method. To predict the Young's moduli of the oxide glass systems, empirical compositional parameters Gi and Vi, based on the Makishima-Mackenzie theory, were obtained, where Gi is the dissociation energy and Vi the packing density parameter of a single-component oxide. The relationship between the calculated Young's modulus from the compositional parameters and the measured Young's modulus was investigated. Experimental results indicated that the Young's modulus of phosphate and tellurite glasses could not be predicted using these parameters. Thus, it was necessary to modify the Gi, by considering P2O5 and TeO2 as glass network formers. As for the phosphate glass, it exhibited a layered structure that consisted of P=O double bond and three chains of P-O bond. In this paper, the modified Gi of P2O5 was calculated using the assumption that the P=O double bond is a nonbridging bond and does not contribute to Young's modulus. In the case of tellurite glass, the glass structure is mainly composed of TeO4 trigonal pyramids, and the addition of other oxides results in structural changes to the TeO3 trigonal pyramid. However, the mechanisms of such structural changes have not yet been clarified. Therefore, the modified Gi of TeO2 was calculated from the measured value using the density and Young's modulus of pure TeO2 glass. The results revealed that the calculated values using our proposed parameter were in good agreement with measured values all through the oxide glasses.

The densities of xBi2O3·(100−x)B2O3 binary melts (x= 0–100 mol%) have been measured systematically in the temperature range of 973 to 1373 K using the Archimedean double-bob method. In addition, the molar volume and coefficient of volume expansion have been determined from these density measurements. The density of melts in the Bi2O3–B2O3 binary system decreased with increasing temperature for all compositions, and increased with increasing Bi2O3 content. The molar volume calculated at 1273 K showed a minimum at around 20–30 mol% Bi2O3. The deviation of molar volume from ideality and the partial molar volumes of B2O3 and Bi2O3 single-component melts were calculated, and the relationships between these properties and Bi2O3 content were investigated. The Δ(MV) (deviation of molar volume from ideality) was negative in the Bi2O3–B2O3 binary melts and showed a minimum of −7.5 cm3 (−17.3%) at 40 mol% Bi2O3 and 1273 K. The PMV (partial molar volume) of the B2O3 melt decreased with increasing Bi2O3 content, up to 70 mol% Bi2O3, and was constant above 70 mol% Bi2O3. The PMV of the Bi2O3 melt was constant up to 30 mol% B2O3 (considered from the viewpoint of Bi2O3), and then decreased sharply with further addition of B2O3. The coefficient of volume expansion increased sharply up to 20 mol% Bi2O3 and decreased with further addition of Bi2O3 at 1273 K. From this result, it can be inferred that the temperature-induced structural changes taking place in the melts are greatest at 20 mol% Bi2O3.

The effect of B2O3 addition on the thermal stability of BaO–P2O5 glasses is studied by differential thermal analysis (DTA), X-ray diffraction (XRD) analysis, scanning electron microscopy, and micro-Raman spectroscopy. The difference between glass-transition and onset-crystallization temperatures increases monotonically with increasing B2O3 concentration. The DTA result reveals that no exothermic peak due to surface crystallization exists in the BaO–P2O5 glass doped with 3 mol% B2O3. A single-mode BaO–P2O5-B2O3 glass fiber could be fabricated by a rod-in-tube technique. The modification of glass structure due to B2O3 addition is qualitatively discussed.

The density, surface tension, and viscosity of the melts from the PbO-B2O3-SiO2 system have been measured at temperatures in the range 1073–1473 K. The effect of composition on these properties was also investigated. The density of the melt was found to increase linearly with increasing PbO content. Molar volume was derived from the density data, and its deviation from the additivity of partial molar volumes was calculated. These deviations in molar volume from those obtained from additivity rules have been used along with the ratio of various coordination numbers of boron (as reported by Bray) to discuss the structure of the melts. The surface tension was found to decrease with decreasing SiO2/B2O3 ratio, and to increase in the range of the PbO content between 30 and 60 mol%, showing a maximum at ∼60 mol% PbO, and then decreased with further additions. This result suggested that the surface tension would be affected primarily by the B2O3 content in the range of the PbO content between 30–60 mol%, and mainly by the PbO content in the range of the PbO content >60 mol%, respectively. The viscosity of the melt was found to decrease linearly with increasing PbO content. The results obtained indicate that the increase in viscosity with B2O3 was half that of SiO2 (on a molar basis), and an empirical equation has been proposed for the viscosity as a function of mole fraction.

Transparent pyrex glasses were obtained by sintering a green compact, which was fabricated by using CIP method for pyrex glass powder, in diverse atmosphere (air, Ar, He and vacuum (10-2Pa)) at 973-1173K. Effects of sintering conditions (temperature and atmosphere) on transmittance of sintered glasses were investigated. Devitrification resulting from crystallization of cristobalite arose in all atmosphere at temperatures over 1023K. Optimum sintering condition for fabricating transparent sintered pyrex glass was at 1003 K for 1hour in a vacuum (10-2 Pa) or He atmosphere in this work. The transparency was 15∼20% in visible region and was about 60% in infrared region. The relationship between transparency and condition of the sintered glasses was discussed in terms of permeation constant of gas species during sintering.

Heat capacities of vitreous silica, and some binary and ternary silicate, borate and phosphate glasses were measured in the temperature range from 300 to 840 K by ac calorimetry. Our previous study has revealed that heat capacities of oxide glasses scaled with the molar heat capacity at the Debye temperature have a similar magnitude and temperature dependence from 300 K to glass transition temperatures. On the basis of this observation, the factor effecting heat capacity was investigated by use of the three-band theory which is composed of separate contributions from one- and three-dimensional Debye model and Einstein model. We revealed that the heat capacity of oxide glass in the temperature range of measurements follows the one-dimensional Debye model and the compositional variations of heat capacity are evaluated in terms of the ionic packing ratio and the dissociation energy of oxide glass.

This article reviews the phase diagrams contributing to the understanding of compound formations, phase transformations, phase separation and microstructural development in advanced ceramic systems. Phase equilibrium relations in the Al 2 O 3 -AlN and AlN-B 2 O 3 systems are presented for the fabrication of translucent aluminum oxynitride spinel ceramics and in-situ hexagonal boron nitride composites. In oxide systems, especially in glass-forming systems, crystallized phases vary with not only composition and temperature but also time of heat-treatment. Considering this aspect, time-temperature-transformation (TTT) diagrams in the solidification processes of cordierite, high-T c superconducting oxide and fluorphlogopite melts and the phase transformations of ammonium aluminum carbonate hydroxide to α-alumina are introduced and specific phase transformations in these systems are also discussed. The effect of treatment atmosphere on microstructure in phase transformations is described in the surface-treatment of AlN ceramics and the sintering of transparent silica glass.

The density, surface tension and viscosity of the 50RO–50P2O5 (R: Mg, Ca, Sr, Ba and Zn) glass melts have been measured over the range, 1073–1623 K. The effects of R cations on these properties have been investigated. The density of the melt was found to increase in the order, R: Mg Ca Zn Sr Ba, with increasing molar weight of cation. The surface tension in the temperature range of 1373–1473 K increased approximately with cation in the order, R: Zn Ba Mg Ca Sr. The viscosity and the negative, temperature coefficient of surface tension increased in the order, R: Ba Sr Ca Zn Mg. All melts exhibited negative temperature coefficients of surface tension. The effect of Mg and Zn cations on the properties were different to that for Ba, Sr, and Ca cations and this is discussed using bulk glass data published in a previous report. The features of Mg and Zn metaphosphate glass melts, that is high values of viscosity, and temperature coefficient of surface tension, are related to the small Oxygen Coordination Number of the cations (=4) when compared with those of Ca, Sr, Ba metaphosphate glass melts.

Gallium sulfide glasses were prepared in the RS-Ga2S3 (R=Ca, Sr, Ba) systems. Respective glass forming regions are 67.5-70.0 mol% CaS, 63.8-68.8 mol% SrS and 60.0-73.8 mol% BaS. Transmission spectra in the visible region, refractive index and glass transition and onset crystallization temperatures were measured for representative compositions of SrS- and BaS-Ga2S3 transparent glasses. Raman spectroscopy reveals that RS-Ga2S3 glasses consist of the network of GeS4 tetrahedra due to the RS addition. The compositional dependence of molar volume indicates a plateau region at 65-70 mol% RS in SrS- and BaS-Ga2S3 glasses. The morphology of sulfur complex anions in RS-Ga2S3 glass melts is discussed using the sulfur-to-gallium ratio as a variable parameter. The combined results suggest that well-developed glass networks are formed near 66.7 mol% RS (S/Ga=2.5) in the SrS- and BaS-Ga2S3 systems.

Dense CaS ceramics were prepared by liquid-phase sintering with Ga2S3 additives (0 ∼ 1.0 mol%). A relative density of 96.2% was achieved by the sintering of CaS samples with 0.5mol% Ga2S3, fired at 1573K for 6h in Ar flow. Sintering process was investigated with scanning electron microscopy observations and linear shrinkage measurements. The sintering process of Ga2S3-doped CaS was found to be followed by 3 steps: (1) the rearrangement of CaS particles by CaS-Ga2S3 liquid, (2) the dissolution of CaS particles and the precipitation of CaS grains due to diffusion-controlled process and (3) the growth of precipitated CaS grains. X-ray diffraction and microstructural analyses with an energy dispersive X-ray fluorescence spectrometer revealed that sintered CaS has mainly CaS phase and CaS-Ga2S3 liquid segregated around grain boundaries. The thermal expansion coefficient of sintered CaS was 19.1 × 10-6/K in the range room temperature to 1273K. It was suggested that ceramic materials with similar thermal expansion coefficients are appropriate for the substrate of CaS based thin film electroluminescence.

Red fluorescent properties of Mn2+ in oxide compounds were investigated in order to improve the chromaticity of red emitting-phosphors. Mg4Ta2O9 and Mg4Nb2O9 with corundum-type structure were selected for the matrix of Mn2+ based on the ionic radius and oxygen coordination number of Mn2+ site. Mg4Ta2O9 : Mn2+ with excitation of 254 nm shows a red fluorescence centered at 660 nm due to the 4T1→6A1 transition of Mn2+. On the other hand, Mn ions in Mg4Nb2O9 do not show any fluorescence. The measured CIE chromaticity value of the red fluorescence of Mg4Ta2O9 : Mn2+ is x = 0.713, y = 0.287; therefore the chromaticity of red fluorescence of Mg4Ta2O9 : Mn2+ is better than that of commercially available Y2O3 : Eu3+ with x = 0.630, y = 0.365. However, the red fluorescence intensity of Mg4Ta2O9 : Mn2+ is about one-third that of Y2O3 : Eu3+. The compositional dependence of fluorescent properties of Mn ions in Mg4Ta2O9 and Mg4Nb2O9 with corundum-type structure was discussed in terms of stability of crystal structure. The relationship between the preparation conditions and the red fluorescence intensity of Mg4Ta2O9 : Mn2+ was also discussed based on the redox of Mn ions.

Red phosphorescence properties on Mn ions doped MgO–GeO2 compounds, Mg4GeO6, Mg2GeO4, and MgGeO3, were investigated. The red phosphorescence was observed in MgGeO3:Mn2+. The red phosphorescence intensity of MgGeO3:Mn2+ increased with adding the MgF2 and Yb2O3. The red phosphorescence duration time of sample with a batch composition of 44 mol%-MgO, 6 mol%-MgF2, 50 mol%-GeO2, 0.1 mol%-MnO, and 0.05 mol%-Yb2O3 is approximately 30 min. The mechanism of red phosphorescence in MgGeO3:Mn2+ is discussed in terms of the relationship between valency state of manganese ions and point defects in matrix compound.

Heat capacities of vitreous silica, and some binary and ternary silicate, borate, and phosphate glasses were measured in the temperature range from 300 to 840 K by AC calorimetry. In this method, the conditions of measurement, especially AC frequency and sample thickness, must be examined in order to measure the heat capacity with high accuracy, and thus, an optimum condition for measuring the heat capacity was investigated. The relationship between heat capacity and chemical composition was discussed in terms of the Debye model, which can be used for calculation of the heat capacity of atomic solids. We found that heat capacities of all the samples studied here scaled with the molar heat capacity at the Debye temperature have a similar magnitude and temperature dependence, from 300 K to the glass transition points. Based on this observation, we propose an empirical equation which is composed of separate contributions of the compositional and temperature dependence of the heat capacity.

Six different types of ZrO2/Ni composite materials were fabricated by means of the slip casting method to study the effects of composition and dispersiveness on their deformation and fracture properties. The result of three-point bend testing indicated that the composition had significant influence on the bend strength and absorbed fracture energy with sufficient dispersiveness, whereas there was little effect on these properties with insufficient dispersiveness. The result of mode I fracture testing also exhibited that the critical mode I energy release rate, GIc, depended upon the composition, and the sufficient dispersiveness resulted in better GIc than the insufficient dispersiveness. The microstructures and fracture behaviors of the composites were examined using a laser microscope, an optical microscope with an image analysis technique and a scanning electron microscope (SEM). The result of the image analysis showed that the compositions of the sintered materials were different from those of the compacts. The SEM observation also exhibited that in the materials with insufficient dispersiveness, cracks tended to propagate along the interfaces of Ni aggregations, resulting in the degradation of the fracture properties.

Extended X-ray absorption fine structure measurements have been performed on Yb3+ in silicate, borate, phosphate, and gallate glasses in order to investigate the local structures surrounding Yb3+. The local structures of Yb3+ ions in silicate, borate, and phosphate glasses were similar to those of Er3+ ions. Yb3+ ions do not occupy the network structural sites, but sit around the terminal region of the network or the region between the networks in these glasses. On the other hand, Yb3+ ions substitute the Ga3+ sites in complex anion structural units of the K2O–Ga2O3–Nb2O5 glasses. We classified the local structures surrounding Yb3+ ions in oxide glasses into two types: the former and the latter are interstitial and substitutive types, respectively. The relationship between the spontaneous emission probability for 2F5/2→2F7/2 transition of Yb3+ and the local structure of Yb3+ in oxide glasses are discussed in terms of these two types.

Transparent silica glasses were obtained by sintering a green compact (fabricated by slip-casting methods for high-purity silica glass powder) in diverse atmospheres. The relationships between sintering atmosphere and sintering temperature that result in transparent, sintered silica glass were shown. The results indicate that there are four forming phases for each sintering atmosphere and temperature: (1) nontransparent glass resulting from an overabundance of pores (2) crystal, such as cristobalite or β-quartz, (3) moganite, and (4) transparent glass. Optimum sintering temperature for fabricating transparent silica glass was above 1673 K in a high-vacuum (10−4 Pa: p(O2)=10−14) atmosphere. We investigate the fabrication of transparent and hydroxyl-free silica glass by a powder-sintered method. After studying the effect of sintering schedule on residual [OH−] concentration for transparent, sintered silica glasses, we sintered a green compact prepared by silica powders with a mean particle size of 1.6 μm, first heating it to 1523 K for dehydration and then to 1873 K for densification. This typical fabricated condition resulted in a transparent, sintered silica glass with

Optical transmission and refractive indexes in vacuum ultraviolet (VUV) region are very important and provide basic data for lens systems in micro lithography equipments and substrate materials using F2 excimer laser as a lightsource. High purity multi-component fluoroberyllate glasses are promising candidates for the deep UV transmitting optical materials due to their exceptionally large optical band gaps compared to those of the other fluoride glass systems. The optimum glass composition for VUV glass material were introduced in terms of glass forming ability and VUV absorption of impurities in the glasses. We also measured refractive indexes of the glasses in VUV region. In order to predict the refractive index, we presented compositional parameter for fluoride glass based on our measured data.

Ca-α SiAlON powders were prepared by carbothermal reduction–nitridation of CaO–Al 2 O 3 –SiO 2 glasses at 1450 °C for 2 h in nitrogen. The content of Ca-α SiAlON phase was 65–81% in the products, and the other phases were AlN and β-SiAlON. The products contained hollow spheres with the size of around 5 μm in diameter. The particle morphology was almost identical to that of Ca-α SiAlON prepared from CaCO 3 –Al 2 O 3 –SiO 2 powder mixtures.

Enormous quantities of radionuclides were released into the ocean via both atmospheric deposition and direct release as a result of the Fukushima Dai-ichi Nuclear Power Plant (FNPP) accident. This study discusses the southward dispersion of FNPP-derived radioactive cesium (Cs) in subsurface waters. The southernmost point where we found the FNPP-derived (134)Cs (1.5-6.8 Bq m(-3)) was 18 °N, 135 °E, in September 2012. The potential density at the subsurface peaks of (134)Cs (100-500 m) and the increased water column inventories of (137)Cs between 0 and 500 m after the winter of 2011-2012 suggested that the main water mass containing FNPP-derived radioactive Cs was the North Pacific Subtropical Mode Water (NPSTMW), formed as a result of winter convection. We estimated the amount of (134)Cs in core waters of the western part of the NPSTMW to be 0.99 PBq (decay-corrected on 11 March 2011). This accounts for 9.0% of the (134)Cs released from the FNPP, with our estimation revealing that a considerable amount of FNPP-derived radioactive Cs has been transported to the subtropical region by the formation and circulation of the mode water.