Study on Sintering of Iron Ores. I : Reducibility of Iron Oxide Materials

The briquett-samples containing Fe_2O_3. SiO_2 and CaO were heated at 1, 200℃ and 1, 300℃ in the atmosphere of air or of mixed gas of CO and CO_2 so that the iron oxides might occur as hematite or magnetite or wustite. These samples were deoxidized with CO or H_2 at 900℃, and their reducibility, expressed as a value of comparative reducibility, was determined from their own reduction curve. The influence of composition of raw materials and of sintering atmosphere on reducibility was confirmed. Their porosity was determined, and also the relation between reducibility and porosity was discussed. The results obtained from this investigation were as follows ; in the atmosphere of air, SiO_2 and CaO contents of iron oxide materials seemed to have little effect on reducibility of iron oxide, and it appears that reducibility varied directly with porosity when iron oxide mixtures were heated at 1, 200℃, but there was found no longer such a clear relationship when heated at 1, 300℃. In the reducing atmosphere, even a little amount of SiO_2 in the iron oxide materials gave undesirable effect on reducibility, and addition of CaO together with SiO_2 could not so much recover it as decreased it, till CaO was added enough for the content of SiO_2. There was found no direct relationship between reducibility and porosity, and the more reducing the atmosphere was more evident the tendency became

Relaxing Constraints on Inflation Models with Curvaton

We consider the effects of the curvaton, late-decaying scalar condensation, to observational constraints on inflation models. From current observations of cosmic density fluctuations, severe constraints on some class of inflation models are obtained, in particular, on the chaotic inflation with higher-power monomials, the natural inflation, and the new inflation. We study how the curvaton scenario changes (and relaxes) the constraints on these models.Comment: 18 pages, 6 figure

Perovskite solar cells with CuI inorganic hole conductor

An organic material, 2,2\u27,7,7\u27-tetrakis(N,N-di-p-methoxyphenylamine)9,9\u27-spirobifluorene (spiro-OMeTAD), is generally used as a hole conductor of perovskite solar cells (PSCs), but spiro-OMeTAD is much more expensive than other materials used in PSCs. In this study, we have prepared PSCs with a cost-effective CuI hole transport layer by spin coating. The merit of using spin coating for CuI is good compatibility with other steps, such as spin coating of a TiO2 electron transport layer and a perovskite active layer. The CuI-based PSC recorded power conversion efficiencies of η = 2.22% (max) on the day of production and η = 6.52% (max) after the 20 days of production. Moreover, the CuI-based PSC had a smaller hysteresis than the spiro-based PSC, suggesting that CuI is a highly promising alternative hole conductor for PSCs

Scaled dynamic loading tests on seismic isolation bearing excluding the contamination of friction and inertia forces

Conventional seismic isolation-bearing testing facilities require moving horizontal platens under high compression. However, these dynamic moving platens inevitably lead to the friction and inertial forces generated by large vertical loads and inertial forces due to the dynamic mass action of the moving platen, which eventually affects the accuracy of the measured force. To solve this problem, the authors have proposed a direct reaction force measurement system (horizontal-vertical separated type) that can exclude the contamination of friction and inertial forces. Measuring pure reaction forces without the contamination of friction forces and inertia is crucial for the reliability of test results. In this paper, prior to the construction of large-scale facility, reduced-size–mockup dynamic tests were conducted using the proposed measurement concept, and its validity and accuracy were discussed. Furthermore, this system was applied to hybrid simulation tests, and the significant improvement of the proposed measurement system was observed