The development of tritium breeder, neutron multiplier and flow channel insert materials for the breeding blanket of the DEMO reactor is reviewed. Present emphasis is on the ITER test blanket module ...(TBM); lithium metatitanate (Li2TiO3) and lithium orthosilicate (Li4SiO4) pebbles have been developed by leading TBM parties. Beryllium pebbles have been selected as the neutron multiplier. Good progress has been made in their fabrication; however, verification of the design by experiments is in the planning stage. Irradiation data are also limited, but the decrease in thermal conductivity of beryllium due to irradiation followed by swelling is a concern. Tests at ITER are regarded as a major milestone. For the DEMO reactor, improvement of the breeder has been attempted to obtain a higher lithium content, and Be12Ti and other beryllide intermetallic compounds that have superior chemical stability have been studied. LiPb eutectic has been considered as a DEMO blanket in the liquid breeder option and is used as a coolant to achieve a higher outlet temperature; a SiC flow channel insert is used to prevent magnetohydrodynamic pressure drop and corrosion. A significant technical gap between ITER TBM and DEMO is recognized, and the world fusion community is working on ITER TBM and DEMO blanket development in parallel.
Various soft actuators have been investigated to overcome the drawbacks of conventional solid machines and explore the applications of soft robotics. In particular, and because they are expected to ...be applicable in minimally invasive medicine because of their safety, soft inflatable microactuators using an actuation conversion mechanism from balloon inflation to bending motion have been proposed for high-output bending motion. These microactuators could be applied to create an operation space by safely moving organs and tissues; however, the conversion efficiency could be further improved. This study aimed to improve conversion efficiency by investigating the design of the conversion mechanism. The contact conditions between the inflated balloon and conversion film were examined to improve the contact area for force transmission, with the contact area dependent on the length of the contact arc between the balloon and force conversion mechanism and on the amount of balloon deformation. In addition, surface contact friction between the balloon and film, which affects actuator performance, was also investigated. The generated force of the improved device is 1.21 N at 80 kPa when it bends 10 mm, which is 2.2 times the generated force of the previous design. This improved soft inflatable microactuator is expected to assist in performing operations in a limited space, such as in endoscopic or laparoscopic operations.
Three series of water-soluble anthracene-appended benzoxaboroles 1a-c were developed; their binding affinity toward cis-1,2-diols was explored by conventional fluorescence titrations to demonstrate ...the role of benzoxaborole as a general recognition motif of cis-1,2-diols for fluorescent probes. The complex structures of the tetra-coordinated boronate adducts between 1 and the cis-1,2-diols were revealed.
In this work, we present the integration of a valve into the pressure supply channel for a pneumatic balloon actuator (PBA). We employed a microvalve using a thermally responsive fluid (Pluronic® ...F127 solution) as the valve which integrates in the PBA. The viscosity of Pluronic® F127 solution can be controlled by a heater integrated into the supply channel to close and open the channel.
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This paper shows the integration of a valve into the pressure supply channel for a pneumatic balloon actuator (PBA). We employed a microvalve using a thermally responsive fluid as the valve that integrates with the PBA. Aqueous Pluronic® F127 solutions are thermally responsive fluids that change their viscosity as a function of temperature. The viscosity of a Pluronic® F127 solution can be controlled by a heater integrated into the supply channel to close and open the channel. In this paper we also show the measured pressure resistance of the microvalve and the demonstration of a PBA integrated with a microvalve. The integration of a valve into the pneumatic actuator allows designing compact pneumatic actuator systems.
•Evolution of fusion power in DD start up with updated plasma models are calculated.•The effect of blanket properties on tritium inventory is assessed.•The effect of helium particle confinement time ...on fusion power is assessed.
Flow and stock of fuels in a fusion reactor has been investigated from the aspect of system-dynamics. In particular, operational scenario of the start-up only by deuterium has been discussed with an integrated model of burning plasmas including effects of dilution due to helium ash. The start-up only from deuterium has been attracting interests since initial loading of tritium in a fusion reactor is a critical issue because of limited availability of tritium. The present work solves the flow of tritium in a reactor with advanced modeling of plasma compared to a previous work. The temporal evolution of plasma temperature has been solved in an integrated manner of temperature and density profiles, an empirical scaling of energy confinement time, isotope effect of confinement, slowing down and velocity distribution function of energetic particles, dilution due to helium ash, and radiation losses. Performance of a reactor in terms of fusion power as well as tritium breeding has been assessed.
Summary
Background
Having an allergic disease may have health implications beyond those more commonly associated with allergy given that previous epidemiological studies have suggested that both ...atopy and allergy are linked to mortality. More viable immune functioning among the elderly, as indicated by the presence of an allergic disease, might therefore be associated with differences in all‐cause mortality.
Objective
Using data from a Japanese cohort, this study examined whether having pollinosis (a form of allergic rhinitis) in a follow‐up survey could predict all‐cause and cause‐specific mortality.
Methods
Data came from the Komo‐Ise cohort, which at its 1993 baseline recruited residents aged 40–69 years from two areas in Gunma prefecture, Japan. The current study used information on pollinosis that was obtained from the follow‐up survey in 2000. Mortality and migration data were obtained throughout the follow‐up period up to December 2008. Proportional hazard models were used to examine the relation between pollinosis and mortality.
Results
At the 2000 follow‐up survey, 12% (1088 of 8796) of respondents reported that they had pollinosis symptoms in the past 12 months. During the 76 186 person‐years of follow‐up, 748 died from all causes. Among these, there were 37 external, 208 cardiovascular, 74 respiratory, and 329 neoplasm deaths. After adjusting for potential confounders, pollinosis was associated with significantly lower all‐cause hazard ratio 0.57 (95% confidence interval = 0.38–0.87) and neoplasms mortality hazard ratio 0.48 (95% confidence interval = 0.26–0.92).
Conclusions and clinical relevance
Having an allergic disease (pollinosis) at an older age may be indicative of more viable immune functioning and be protective against certain causes of death. Further research is needed to determine the possible mechanisms underlying the association between pollinosis and mortality.
Tritium breeding performance of a fusion blanket is a key parameter for the self-sufficient fueling of a fusion reactor, and thus designed to validate the performance of a neutronics experiment. ...Measuring the 2-D distribution of bred tritium is challenging via conventional methods such as <inline-formula> <tex-math notation="LaTeX">\beta </tex-math></inline-formula>-ray counting from an irradiated lithium sample using a liquid scintillation counter (LSC) and a single-crystal diamond detector with a thin 6 LiF film, because they are point detectors which require many measurements. In this article, 2-D distribution of the low quantity produced tritium was evaluated with a neutron imaging plate (NIP) with a Gd convertor by estimating the loss of neutrons via a capture reaction by Li. Deuterium-deuterium (DD) fusion neutrons were generated using a compact fusion device at an average neutron production rate of <inline-formula> <tex-math notation="LaTeX">1.5 \times 10 ^{5} </tex-math></inline-formula> n/s by applying high voltages. A neutron image with "shadows" projected by thermal neutron capture reactions of 6 Li(n,<inline-formula> <tex-math notation="LaTeX">\alpha </tex-math></inline-formula>) and 10 B (n,<inline-formula> <tex-math notation="LaTeX">\alpha </tex-math></inline-formula>) was successfully obtained. The experimentally evaluated values were confirmed to be consistent with the total number of capture reactions calculated using a neutron transport code. The results suggest that the approach could be a facile method for the 2-D evaluation of bred tritium.
Highlights • Brain-behavior correlations during response inhibition developed temporally. • The correlations became more robust in a later period of an experimental session. • The correlation change ...was attributable to a change in participants’ brain activity. • Brain activity increased in good performers while it decreased in poor performers.
By extending Schwarz's (1978) basic idea we derive a Bayesian information criterion which enables us to evaluate models estimated by the maximum penalised likelihood method or the method of ...regularisation. The proposed criterion is applied to the choice of smoothing parameters and the number of basis functions in radial basis function network models. Monte Carlo experiments were conducted to examine the performance of the nonlinear modelling strategy of estimating the weight parameters by regularisation and then determining the adjusted parameters by the Bayesian information criterion. The simulation results show that our modelling procedure performs well in various situations.
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