Review of Japan's power generation scenarios in light of the Fukushima nuclear accident

Following on from the Fukushima Daiichi nuclear power plant accident, the Japanese government is now in the throes of reviewing its power policy. Under continuing policies of economic revival and greenhouse gas reduction, it is crucial to consider scenarios for the country to realize reliable, low‐carbon, and economic electricity systems in the future. On the other hand, the social acceptance of nuclear power will affect the final political decision significantly. Therefore, in the present study, proposed power generation scenarios in Japan in light of the Fukushima accident were reviewed comprehensively from economic, environmental, technological, resource, security, and social perspectives. The review concludes that in Japan, (i) renewable energy mainly solar and wind needs to be developed as fast as possible subject to various constraints, (ii) more gas power plants will be used to absorb the fluctuations of intermittent renewable energy and supply electricity gap, (iii) nuclear power will be reduced in the future, but a 0% nuclear power scenario by 2030 is unlikely to be a reasonable choice on most measures and (iv) the effective communication with the public is vital important. Copyright © 2014 John Wiley & Sons, Ltd.     

Archaeological Arsenical Bronzes and Equilibrium in the As-Cu System

Metallurgical and Materials Transactions B - Understanding the effects of impurities, segregation, undercooling, and solidification velocity is necessary to reconstruct prehistoric As-Cu alloy...     

The nanometre-scale physiology of bone: steric modelling and scanning transmission electron microscopy of collagen�Cmineral structure

The nanometre-scale structure of collagen and bioapatite within bone establishes bone''s physical properties, including strength and toughness. However, the nanostructural organization within bone is not well known and is debated. Widely accepted models hypothesize that apatite mineral (‘bioapatite’) is present predominantly inside collagen fibrils: in ‘gap channels’ between abutting collagen molecules, and in ‘intermolecular spaces’ between adjacent collagen molecules. However, recent studies report evidence of substantial extrafibrillar bioapatite, challenging this hypothesis. We studied the nanostructure of bioapatite and collagen in mouse bones by scanning transmission electron microscopy (STEM) using electron energy loss spectroscopy and high-angle annular dark-field imaging. Additionally, we developed a steric model to estimate the packing density of bioapatite within gap channels. Our steric model and STEM results constrain the fraction of total bioapatite in bone that is distributed within fibrils at less than or equal to 0.42 inside gap channels and less than or equal to 0.28 inside intermolecular overlap regions. Therefore, a significant fraction of bone''s bioapatite (greater than or equal to 0.3) must be external to the fibrils. Furthermore, we observe extrafibrillar bioapatite between non-mineralized collagen fibrils, suggesting that initial bioapatite nucleation and growth are not confined to the gap channels as hypothesized in some models. These results have important implications for the mechanics of partially mineralized and developing tissues.     

Intelligent acoustic rotor speed estimation for an autonomous helicopter

Acoustic sensing to gather information about a machine can be highly beneficial, but processing the data can be difficult. In this work, a variety of methodologies have been studied to extract rotor speed information from the sound signature of an autonomous helicopter, with no a-priori knowledge of its underlying acoustic properties.     

Poly(vinyl alcohol) functionalization with aldehydes in organic solvents: Shining properties of poly(vinyl acetals)

Poly(vinyl alcohol) has been functionalized with aldehydes in tetrahydrofuran (THF) with a good control of the grafting. A wide library of poly(vinyl acetals) could be obtained in order to study some structure/property correlations. The influence of the aldehyde nature on the functionalization rates has been studied, in particular for optical properties by measurement of the shininess for further applications in the cosmetic field. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40677.     

Impact of Brownian motion on the particle settling in molten metals

Understanding the settling behavior of nanoparticles in molten metals/alloys is important as it will aid in achieving uniform dispersions of reinforcement particles in metal matrix nanocomposites. Uniform dispersions are necessary to activate the Orowan strengthening mechanism, which can increase yield strength without significant diminishment of ductility. In this work, an analytical model of particle size effects on settling is described that takes into account both deterministic Stokes’ law and stochastic Brownian motion. The model shows a clear transitional behavior where settling velocity follows Stokes’ law for large particles and then drops to zero for small particles implying that Brownian motion predominates. It indicated that, in the Brownian motion regime, where the discrete nature of the liquid must be considered, the random motion imparted by unbalanced collisions can overwhelm the motions normally imposed by forces such as gravity, viscous drag, and thermal/concentration gradients.     

Interaction rules underlying group decisions in homing pigeons

Travelling in groups gives animals opportunities to share route information by following cues from each other''s movement. The outcome of group navigation will depend on how individuals respond to each other within a flock, school, swarm or herd. Despite the abundance of modelling studies, only recently have researchers developed techniques to determine the interaction rules among real animals. Here, we use high-resolution GPS (global positioning system) tracking to study these interactions in pairs of pigeons flying home from a familiar site. Momentary changes in velocity indicate alignment with the neighbour''s direction, as well as attraction or avoidance depending on distance. Responses were stronger when the neighbour was in front. From the flocking behaviour, we develop a model to predict features of group navigation. Specifically, we show that the interactions between pigeons stabilize a side-by-side configuration, promoting bidirectional information transfer and reducing the risk of separation. However, if one bird gets in front it will lead directional choices. Our model further predicts, and observations confirm, that a faster bird (as measured from solo flights) will fly slightly in front and thus dominate the choice of homing route. Our results explain how group decisions emerge from individual differences in homing flight behaviour.     

Multifunctional glow discharge analyzer for spacecraft monitoring

In this study the main objective was to develop and demonstrate a glow discharge microplasma coupled to a miniature spectrometer for detection of fire signatures from pyrolyzing and burning spacecraft materials. Our experimental results demonstrate that combustion-produced carbonaceous aerosols can serve to identify the burning materials. Demonstrating versatility for chemistry analysis, the plasma detector could differentiate carbonaceous aerosols with different C/H ratios and distinguish inorganic samples such as salts and metal oxides from carbonaceous aerosols. In addition, in situ analysis of aerosol samples validated the microplasma’s analytical utility by linearity of its optical emission intensity with aerosol elemental composition.     

Dehydrogenation kinetics and catalysis of organic heteroaromatics for hydrogen storage

The complete recovery of the H₂ stored on dodecahydro-N-ethylcarbazole was achieved at 443 K and 101 kPa using Pd catalysts prepared by incipient wetness impregnation and calcination in He rather than air. Over a 4 wt% Pd/SiO₂ catalyst, the reaction proceeded to complete conversion within 22 min and complete H₂ recovery (5.8 wt%) within 1.6 h. The dehydrogenation rate of dodecahydro-N-ethylcarbazole and selectivity to the completely dehydrogenated product, N-ethylcarbazole, were dependent upon the Pd particle size. The dehydrogenation rate of dodecahydro-N-ethylcarbazole was compared to that of dodecahydrocarbazole and dodecahydrofluorene. The lower turn-over frequency (TOF) for dodecahydrocarbazole was attributed to a strong adsorption of the dehydrogenated products to Pd through the N atom, whereas the ethyl group in dodecahydro-N-ethylcarbazole prevented a strong N interaction with the surface. Density functional theory (DFT) results showed that dodecahydrocarbazole and dodecahydrofluorene were more strongly adsorbed on Pd than dodecahydro-N-ethylcarbazole leading to a significant decrease in their TOFs for H₂ recovery.