Development of a hybrid catalytic combustor for a 1300°C class gas turbine

The hybrid catalytic combustor concept proposed by the authors has an advantage concerned with catalyst durability, because the catalyst is maintained below 1000°C even for application to 1300°C class gas turbines. A full-scale hybrid catalytic combustor has been designed for a 200 MW (1300°C) class gas turbine. The catalyst bed was 450 mm in diameter and consisted of a Pd/ alumina washcoat on a cordierite monolith. In experiments, the combustor has demonstrated the capability of meeting the NO_x emission level of SCR (selected catalytic reduction) during atmospheric pressure testing. To predict the catalyst performance at an elevated pressure, the characteristics of the catalyst were studied using a small scale reactor test, and a material property test using a DTA/TGA-Q.MASS system. The catalyst showed a higher activity in the oxidized state (PdO) than in the metallic state (Pd). This activity difference was governed by the equilibrium of the oxygen release from PdO in bulk. It was considered that oxidation rate of the metallic Pd in bulk was not so high and this caused self-oscillation for the Pd catalyst around the temperature of the oxygen release equilibrium. Even below the temperature of the oxygen release equilibrium, both surface and bulk (lattice) oxygen of the PdO was consumed by the methane oxidation reaction, and resulted in a lack of surface oxygen on the catalyst. This caused a reversible decrease in the catalyst activity during combustion testing, and indicated that the oxygen dissociation step was a rate limiting step in the catalytic combustion.     

Studies on Effective Utilization of SOFC Exhaust Heat Using Thermoelectric Power Generation Technology

Solid oxide fuel cells (SOFCs) are being researched around the world. In Japan, a compact SOFC system with rated alternative current (AC) power of 700 W has become available on the market, since the base load electricity demand for a standard home is said to be less than 700 W AC. To improve the generating efficiency of SOFC systems in the 700-W class, we focused on thermoelectric generation (TEG) technology, since there are a lot of temperature gradients in the system. Analysis based on simulations indicated the possibility of introducing thermoelectric generation at the air preheater, steam generator, and exhaust outlet. Among these options, incorporating a TEG heat exchanger comprising multiple CoSb₃/SiGe-based TEG modules into the air preheater had potential to produce additional output of 37.5 W and an improvement in generating efficiency from 46% to 48.5%. Furthermore, by introducing thermoelectric generation at the other two locations, an increase in maximum output of more than 50 W and generating efficiency of 50% can be anticipated.     

Differential expression of Fos protein after transection of the rat infraorbital nerve in the trigeminal nucleus caudalis

To determine the effects of nerve injury on Fos expression, temporal and spatial distributions of Fos-positive neurons in the trigeminal nucleus caudalis were examined after tissue injury for isolation of the infraorbital nerve as controls and transection of this nerve as well as noxious chemical stimulation by formalin injection in adult rats. Fos immunoreactivity was markedly elevated in laminae I and II of the only ipsilateral nucleus caudalis 2 h after these surgical procedures and noxious chemical stimulation. The distributions of Fos-positive neurons were restricted rostro-caudally following formalin injection and tissue injury compared to transection of the infraorbital nerve. One day after tissue injury and nerve transection, however, Fos-positive neurons were distributed bilaterally in laminae III and IV extending rostro-caudally and medio-laterally in this nucleus, and this persisted over the 2-week study period. The number of Fos-positive neurons in the side ipsilateral to nerve transection was markedly less than that in the contralateral side whereas positive neurons in the tissue injured rats were distributed symmetrically along the rostro-caudal axis. There was no difference in the contralateral sides between nerve transection and tissue injury groups. The rostro-caudal level showing reduction in Fos expression corresponded roughly to the sites of central termination of the injured nerve in this nucleus, suggesting a role for the primary afferents in the reduction of Fos expression in laminae III and IV neurons of the ipsilateral nucleus caudalis.     

Design and Synthesis of A‐Ring Simplified Pyripyropene A Analogues as Potent and Selective Synthetic SOAT2 Inhibitors

Currently, pyripyropene A, which is isolated from the culture broth of Aspergillus fumigatus FO‐1289, is the only compound known to strongly and selectively inhibit the isozyme sterol O‐acyltransferase 2 (SOAT2). To aid in the development of new cholesterol‐lowering or anti‐atherosclerotic agents, new A‐ring simplified pyripyropene A analogues have been designed and synthesized based on total synthesis, and the results of structure–activity relationship studies of pyripyropene A. Among the analogues, two A‐ring simplified pyripyropene A analogues exhibited equally efficient SOAT2 inhibitory activity to that of natural pyripyropene A. These new analogues are the most potent and selective SOAT2 inhibitors to be used as synthetic compounds and attractive seed compounds for the development of drug for dyslipidemia, including atherosclerotic disease and steatosis.     

Correction to: Semi-automation of gesture annotation by machine learning and human collaboration

Language Resources and Evaluation -     

Preparation and cured properties of novel cycloaliphatic epoxy resins

Preparation and characterization of novel cycloaliphatic epoxy resins, which are derived from octadienyl compounds, were studied. From a model peracetic acid epoxidation reaction using 2,7-octadienyl acetate-1, the structure of the liquid resins is estimated to be mainly terminal epoxides and some amount of inner epoxide depending on the epoxide content. The epoxy resins offer lower toxicity and lower vapor pressure. The reactivity of the resin with acid anhydrides is moderate but faster than that of traditional cyclohexane epoxide-type resins and slower than that of the glycidyl ester-type resins. This reactivity was also examined using model compounds. The heat deflection temperature of the hexahydro-phthalic anhydride-cured resins is shown to be directly proportional to the number of epoxy groups in the molecules. The flexural strength of the cured resins is nearly equivalent to that of the commercial resins, although the flexural elongation of the resins is larger than that of the rigid cyclohexane epoxide-type resins. The thermal stability of the cured resins is comparable to typical rigid cycloaliphatic resins; furthermore, high water resistance of the cured resins is suggested to be attributed to the hydrophobic character of the C₈ chain by cross-linking. © 1993 John Wiley & Sons, Inc.     

Comparison of precipitates between excess Si-type and balanced-type Al-Mg-Si alloys during continuous heating

Differential scanning calorimetry (DSC) curves were obtained from Al-1.0 mass pct Mg₂Si (balanced) and Al-1.0 mass pct Mg₂Si −0.4 mass pct Si (excess Si) alloys, and precipitates corresponding to each peak at the DSC curve were interpreted by means of high-resolution transmission electron microscopy (HRTEM) observation in order to understand the precipitation sequence of metastable phases. Five peaks were obtained on the DSC curves, from which four were exothermic (A, C, D, and E) and one endothermic (B). Upon HRTEM observation, the peaks for the excess Si alloy were explained as follows: peak A–B: Guinier-Preston (GP) zones and random-type precipitates; peak B: dissolution of the GP zones and the random-type precipitates, precipitation of the β″ phase; peak C: β″ phase and precipitation of type B; peak D: dissolution of the β″ phase; precipitation of type A and β′ phase; and peak E: dissolution of the type B, type A, and β′ precipitation of the (β+Si) phase. This result is quite different from that in the balanced alloy as follows: peak A–B: GP zones and random-type precipitates; peak B: dissolution of the GP zones and the random-type precipitates, precipitation of the parallelogram-type precipitate; peak C: parallelogram-type precipitate and precipitation of β′ phase; peak D: β′ phase, dissolution of parallelogram-type precipitate; and peak E: the β-(Mg₂Si).