Aseismic study on the reactor vessel of a fast breeder reactor

This paper presents the results of a seismic study using an scale steel model and a scale plastic model which simulate the reactor vessel of a loop type Fast Breeder Reactor (FBR). The main purposes of this study are to confirm the structure/liquid interaction and the aseismic safety of the reactor vessel experimentally, and also to verify the validity of the seismic response analysis model of the prototype vessel.The characteristics of coupled vibration between the structure and liquid were clarified, and the approach of calculation model to aseismic design was worked out. And, the dip plate and other core internals were found to be effective in suppressing the liquid free surface oscillation.     

Statistical fracture theory for multiaxial stress states using weibull's three-parameter function

Assuming that Weibull's three-parameter uniaxial distribution function should be valid only in equi-triaxial tensile stress state, a new multiaxial distribution function having location parameters is formulated involving both effects of internal and surface cracks. Using this new distribution function, the ones in simple and equi-biaxial tensile stresses are derived, and some discussions are performed about fracture probability ratios and expected values of fracture stresses.     

The anodic dehydrodimerization of dimethyl malonate

As a part of a study of the anodic dehydrodimerization of diethyl malonate on platinum in emulsions and micelles some experiments were run to obtain an insight on the mechanism of the reaction. It was determined that although some catalytic dehydrodimerization was obtained with pure diethyl malonate at elevated temperatures the yield from this type of reaction at room temperature was negligible. In pure acetonitrile, confirmation was obtained for the previously postulated mechanism which involved reaction at the anode of electrogenerated halogen with diethyl malonate anions which had been generated at the cathode.In aqueous emulsion and micelle systems it was found that yields of the dimer were obtained in the presence of bromide ions and a quaternary ammonium salt but were not obtained using other supporting anions including chloride. The best yields were obtained in emulsions composed of tetrabutylammonium bromide and water. It was concluded that the dimerization proceeded by a reaction between electrochemically generated bromine molecules and the diethyl malonate anion. No large amounts of bromine were found adjacent to the electrode if potassium bromide was the supporting electrolyte but bromine stayed in the neighborhood of the electrode if tetrabutylammonium ions were present.     

On-site fabrication of ceramics films from solution precursors by ink-jet and spray assisted processes

Solution processing based on Ink-jet and spray technologies is one of low cost on-site ceramic patterns/films fabrication methods at moderate temperatures from precursor solutions. In the present study, we have used ink-jet and spray technologies to fabricate ceramic films of titania directly on glass substrates at 300–400^∘C. The precursor solution was prepared by dissolving Titanium tetraisopropoxide in appropriate solvents (water/ethanol and acetylacetone). A cleaned glass substrate was kept on a hot plate and heated it up to a predetermined temperature. Droplets of the precursor solution produced through a spray gun were traveled towards heated substrate with a atmospheric pressure. When the droplets hit on the heated substrate, precursor started to decompose, nucleate and grow into the TiO₂ film. The anatase pattern was directly obtained by ink-jet method at moderate temperatures.     

Information-theoretic regularization for learning global features by sequential VAE

Machine Learning - Sequential variational autoencoders (VAEs) with a global latent variable z have been studied for disentangling the global features of data, which is useful for several downstream...     

Effect of non-equilibrium condensation of moist air on unsteady behaviour of shock waves around a circular arc blade

The unsteady phenomena in the transonic flow around airfoils are observed in the flow field of fan,compressorblades and butterfly valves,and this often causes serious problems such as the aeroacoustic noise,the vibration.In the transonic or supersonic flow where vapour is contained in the main flow,the rapid expansion of the flowmay give rise to a non-equilibrium condensation.However,the effect of non-equilibrium condensation on thetransonic internal flows around the airfoil has not yet been clarified satisfactorily.In the present study,the effectof non-equilibrium condensation of moist air on the self-excited shock wave oscillation on a circular arc bladewas investigated numerically.The results showed that in the case with non-equilibrium condensation,frequenciesof the flow oscillation became smaller than those without the non-equilibrium condensation.     

Advanced technical textile products

This article is situated to be successive to “Fibre materials for advanced technical textiles” in the series of “Advanced technical textiles” of Textile Progress. In the previous article, fiber materials used for advanced technical textiles are introduced. In this article, advanced technical textiles products are described according to the application fields of the fiber materials. Although this article does not cover all the end-uses, it contains major parts of advanced technical textile products, which include products for resources and environmental issues, for automobiles, for medical uses, for protective uses, for information technologies, for civil engineering and for electronics textiles.     

Highly sensitive detection of net hydrogen charged into austenitic stainless steel with secondary ion mass spectrometry

Secondary ion mass spectrometry (SIMS) is used to detect local distributions of hydrogen in various materials. However, it has been well-known that it is extremely difficult to analyze net hydrogen (H(N)) in metals with SIMS. This was because hydrogen, which is originated from moisture (H(2)O), hydrocarbon (C(x)H(y)) or other organic materials (C(x)H(y)O(z)) existing on a sample surface or in the SIMS chamber, is simultaneously detected in the SIMS measurement of the H(N), and the H(N) and the background-originated hydrogen (H(BG)) cannot be distinguished in a SIMS profile. The effective method for reductions and determinations of the H(BG) in hydrogen measurements of metallic materials with the SIMS method has not been established. The present paper shows an effective method for reduction and estimation of H(BG) in SIMS analyses of hydrogen charged into type 316 L austenitic stainless steel, and an accurate estimation method of the net charged hydrogen. In this research, a silicon wafer is sputtered by a primary ion beam of a SIMS near an analyzed area (silicon sputtering method) to reduce H(BG). An uncharged type 316 L sample was prepared for estimation of H(BG) in SIMS measurements of the hydrogen-charged sample. The gross intensities of hydrogen between the hydrogen-charged sample and the uncharged sample were compared. The gross intensities of hydrogen of the uncharged sample (26.8-74.5 cps) were much lower than the minimal gross intensities of hydrogen of the hydrogen-charged sample (462-1140 cps). Thus, we could reduce the H(BG) enough to estimate the hydrogen charged into the type 316 L sample. Moreover, we developed a method to determine intensities of H(BG) in the measurement of the hydrogen-charged sample by estimating the time-variation of hydrogen intensities in the measurements of the uncharged sample. The intensities of the charged hydrogen can be obtained by subtracting the estimated intensities of the H(BG) from the gross intensities of hydrogen of the hydrogen-charged sample. The silicon sputtering method used to reduce H(BG) and the determination method for H(BG) in this research can be applied to the accurate hydrogen analysis for other various metallic materials.