Elastic modulus and internal friction of SOFC electrolytes at high temperatures under controlled atmospheres

Mechanical properties such as Young's modulus, shear modulus, Poisson's ratio and internal friction of conventional electrolyte materials for solid oxide fuel cells, Zr_0.85Y_0.15 O_1.93 (YSZ), Zr_0.82Sc_0.18O_1.91 (ScSZ), Zr_0.81Sc_0.18Ce_0.01O_2−δ (ScCeSZ), Ce_0.9Gd_0.1O_2−δ (GDC), La_0.8Sr_0.2Ga_0.8Mg_0.15Co_0.05O_3−δ (LSGMC), La_0.8Sr_0.2Ga_0.8Mg_0.2O_3−δ (LSGM), were evaluated by a resonance method at temperatures from room temperature to 1273 K in various oxygen partial pressures. The Young's modulus of GDC gradually decreased with increasing temperature in oxidizing conditions. The Young's moduli of the series of zirconia and lanthanum gallate based materials drastically decreased in an intermediate temperature range and increased slightly with increasing temperature at higher temperatures. The Young's modulus of GDC considerably decreased above 823 K in reducing atmospheres in response to the change of oxygen nonstoichiometry. However, temperature dependences of the Young's moduli of ScCeSZ and LSGMC in reducing atmospheres did not show any significant differences with those in oxidizing atmospheres.     

Perirolandic cortex in infants: signal intensity on MR images as a landmark of the sensorimotor cortex

PURPOSE: To correlate the perirolandic low signal intensity seen on T2-weighted magnetic resonance (MR) images in neonates and infants with the anatomically located sensorimotor cortex. MATERIALS AND METHODS: Axial T2-weighted MR images of 146 consecutive patients less than 6 months old were reviewed. The sensorimotor cortex was located by identifying the central sulcus. Two independent readers attempted to identify the central sulcus using two anatomic methods independently and in combination. The location of the central sulcus was compared with that of the perirolandic low signal intensity. RESULTS: Seventy-two normal hemispheres in 36 patients and 91 abnormal hemispheres in 47 patients showed clear perirolandic low signal intensity. The central sulcus was located anatomically in 70 and 72 normal hemispheres (97% and 100%, respectively) and 90 and 91 abnormal hemispheres (99% and 100%, respectively). In all normal hemispheres, the identified central sulcus correlated with the perirolandic low signal intensity. In contrast, an apparent mismatch was found in two hemispheres in a patient with Dandy-Walker syndrome. CONCLUSION: The perirolandic low signal intensity seen on T2-weighted MR images is located exactly in the anatomic sensorimotor cortex in normal brains, whereas a mismatch can occur in abnormal brains.     

Usefulness of Intratracheal Instillation Studies for Estimating Nanoparticle-Induced Pulmonary Toxicity

Inhalation studies are the gold standard for the estimation of the harmful effects of respirable chemical substances, while there is limited evidence of the harmful effects of chemical substances by intratracheal instillation. We reviewed the effectiveness of intratracheal instillation studies for estimating the hazards of nanoparticles, mainly using papers in which both inhalation and intratracheal instillation studies were performed using the same nanoparticles. Compared to inhalation studies, there is a tendency in intratracheal instillation studies that pulmonary inflammation lasted longer in the lungs. A difference in pulmonary inflammation between high and low toxicity nanoparticles was observed in the intratracheal instillation studies, as in the inhalation studies. Among the endpoints of pulmonary toxicity, the kinetics of neutrophil counts, percentage of neutrophils, and chemokines for neutrophils and macrophages, heme oxygenase-1 (HO-1) in bronchoalveolar lavage fluid (BALF), reflected pulmonary inflammation, suggesting that these markers may be considered the predictive markers of pulmonary toxicity in both types of study. When comparing pulmonary inflammation between intratracheal instillation and inhalation studies under the same initial lung burden, there is a tendency that the inflammatory response following the intratracheal instillation of nanoparticles is greater than or equal to that following the inhalation of nanoparticles. If the difference in clearance in both studies is not large, the estimations of pulmonary toxicity are close. We suggest that intratracheal instillation studies can be useful for ranking the hazard of nanoparticles through pulmonary inflammation.     

Steam electrolysis performance of intermediate-temperature solid oxide electrolysis cell and efficiency of hydrogen production system at 300 Nm h

The steam electrolysis performance of an intermediate-temperature solid oxide electrolysis cell (SOEC) was measured at 650 °C at various steam concentrations. The cell voltage decreased with increasing steam concentration, which was attributed to a decrease in the steam electrode polarization. The highest performance of the SOEC was 1.32 V at 0.57 A cm⁻². On the basis of the electrolytic characteristics of this cell, the efficiency of a hydrogen production system operating at a capacity of 300 N m³ h⁻¹ was estimated. The system efficiency reached a higher heating value (HHV standard) of 98% due to the effective recovery of thermal energy from exhaust gas.     

Effects of sulfur poisoning on degradation phenomena in oxygen electrodes of solid oxide electrolysis cells and solid oxide fuel cells

The durabilities of a single solid oxide electrolysis cell (SOEC) and a solid oxide fuel cell (SOFC) operating at 0.3 A cm^?2 and 973 K under different air supply conditions were investigated. In the SOEC, S penetration was observed mainly at the gadolinium-doped ceria (CGO) electrolyte/lanthanum strontium cobalt oxide (LSC) oxygen electrode interface. In contrast, during SOFC operation, S was distributed widely within the LSC. The reaction governing S penetration into the LSC is an oxidizing one. Thus, it is likely that the high oxygen partial pressure at the CGO electrolyte/LSC oxygen electrode interface accelerated the penetration of S. When air was supplied using an activated carbon filter during SOEC operation, the degradation rate decreased to 0.6% kh^?1 within 3000 h. Finally, the results of accelerated tests performed using air containing 0.2 ppm SO₂ suggested that the effect of S poisoning was greater during SOEC operation than during SOFC operation.     

The Quest for Relevance: Roles for Academia and Industry in Japan and the U.S.

While U.S. industry is making headway in worldwide markets, much remains to be done. Some have proposed that improving the relevance of engineering education can have a marked influence on the future success of U.S. manufacturing. Some in academia have heard industries' cries for help to improve relevancy in engineering education and have responded with various solutions. Is this the situation in Japan? What is the state of engineering education in Japan? Where is it headed and how does the U.S. compare? We found that industry-academia relationships like those being strengthened in the U.S. are minimal in Japan. Surprisingly, Japanese industry and academia appear not to be headed in a collaborative direction and are even more detached from one another than in the United States. This paper presents some differences in the way Japan and the U.S. view their roles for academia and industry and their interrelationships. Our objective is to further motivate U.S. educators to collaborate with industry and continue to integrate greater relevancy into engineering education.     

Development of non-flammable lithium secondary battery with room-temperature ionic liquid electrolyte: Performance of electroplated Al film negative electrode

The negative electrode performance of the electroplated Al film electrode in the LiCl saturated AlCl₃–1-ethyl-3-methylimizadolium chloride (EMIC) + SOCl₂ melt as the electrolyte for use in non-flammable lithium secondary batteries was evaluated. In the cyclic voltammogram of the electroplated Al film electrode in the melt, the oxidation and reduction waves corresponding to the electrochemical insertion/extraction reactions of the Li⁺ ion were observed at 0–0.80 V vs. Li⁺/Li, which suggested that the electroplated Al film electrode operated well in the electrolyte. The almost flat potential profiles at about 0.40 V vs. Li⁺/Li on discharging were shown. The discharge capacity and charge–discharge efficiency was 236 mAh g⁻¹ and 79.2% for the 1st cycle and it maintained 232 mAh g⁻¹ and 77.9% after the 10th cycle. In addition, the initial charge–discharge efficiencies of the electroplated Al film electrode were higher than that of carbon electrodes. The main cathodic polarization reaction was the insertion of Li⁺ ions, and side reactions hardly occurred due to the decomposition reaction of the melt because the Li content corresponding to the electricity was almost totally inserted into the film after charging.     

Polypyrrole–Palladium Nanocomposite-Coated Latex Particles as a Heterogeneous Catalyst in Water

Abstract  

Polypyrrole–palladium nanocomposite-coated cross-linked polystyrene latex particles (PS/PPy–Pd) showed an excellent catalytic activity for Suzuki and Heck reactions in aqueous media. The PS/PPy–Pd can be recovered easily and quantitatively through the repeated uses with simple filtration and they maintain their high catalytic activities.     

Fuel ethanol production from sweet sorghum using repeated-batch fermentation

Ethanol was efficiently produced from three varieties of sweet sorghum using repeated-batch fermentation without pasteurization or acidification. Saccharomyces cerevisiae cells could be recycled in 16 cycles of the fermentation process with good ethanol yields. This technique would make it possible to use a broader range of sweet sorghum varieties for ethanol production.     

Effect of degree of neutralization of sodium-based ionomers on hot-tack properties

The hot-tack properties of ethylene-methacrylic acid copolymers neutralized with sodium (Na) cations to produce ionomers were investigated. Specimens with neutralization degrees of 20%, 54%, and 70% were examined. After testing at low sealing temperatures (<130°C), the highest hot-tack strength was obtained from a specimen with a neutralization degree of 20%. In contrast, at high sealing temperatures (>140°C), the hot-tack strength increased with an increasing degree of neutralization. Observations of the surfaces of samples tested at low sealing temperatures after hot-tack tests showed that specimens having a neutralization degree of 20% exhibited cohesive breakdown while the 54% and 70% specimens underwent interfacial delamination. The effect of sealing temperature on hot-tack strength was determined by assessing the rheological properties of molten ionomers. The results suggested that, when testing at low sealing temperatures, a low melt viscosity provided high hot-tack strength by allowing flow diffusivity of the resin at the sealed interface. At high sealing temperatures, uniaxial elongational viscosity related to strain hardening contributed to the high hot-tack strength of these Na-based ionomers. The present study highlights the important effect of ionic aggregates on hot-tack properties.