Drag minimization and lift maximization in laminar flows via topology optimization employing simple objective function expressions based on body force integration

This paper deals with topology optimization of body shapes in fluid flows, where some new ideas for drag minimization and lift maximization problems are proposed. For drag minimization problems, the objective function is expressed as a body force integration in the flow domain. Also a similar expression of objective function is given for lift maximization problems. Employing those objective function expressions, optimum shapes of bodies in incompressible axisymmetric and two-dimensional flows are numerically investigated.     

Validation of Pb nuclear data by Monte Carlo analyses of sample reactivity experiments at Kyoto University Critical Assembly

Sample reactivity experiments on the uncertainty analyses of Pb nuclear data are carried out by substituting Al plates for Pb ones at the Kyoto University Critical Assembly, as part of basic research on Pb–Bi for the coolant. Numerical simulations of sample reactivity experiments are performed with the Monte Carlo calculation code MCNP6.1 together with four nuclear data libraries JENDL-3.3, JENDL-4.0, ENDF/B-VII.0 and JEFF-3.1, to examine the accuracy of cross-section uncertainties of Pb isotopes by comparing measured and calculated sample reactivities. A library update from JENDL-3.3 to JENDL-4.0 is demonstrated by the fact that the difference between Pb isotopes of the two JENDL libraries is dominant in the comparative study, through the experimental analyses of sample reactivity by the MCNP approach. In addition, JENDL-4.0 reveals a slight difference from ENDF/B-VII.0 in all Pb isotopes and ²⁷Al, and from JEFF-3.1 in ²³⁸U and ²⁷Al. Based on these results, further experiments are needed to investigate the uncertainties of Bi isotopes with the use of the Pb–Bi and Bi plates.     

SOC Estimation of HEV/EV Battery Using Series Kalman Filter

This paper proposes a method of accurately estimating the state of charge (SOC) of rechargeable batteries in high fuel efficiency vehicles, such as hybrid electric vehicles (HEVs) and electric vehicles (EVs). Despite the importance of accurately estimating the SOC of batteries to achieve maximum efficiency and safety, no method thus far has been able to do so. This paper focuses on the simplification of a battery model, estimation of time‐varying battery parameters, and estimation of SOC in the presence of measurement noise. To address these three issues, a model‐based approach that uses a cascaded combination of two Kalman filters, “series Kalman filters,” is proposed and implemented. This approach is verified by performing a series of simulations in an HEV operating environment. The ultimate goal is to design a state estimator capable of accurately estimating the state of any kind of batteries under every possible user condition. © 2014 Wiley Periodicals, Inc. Electr Eng Jpn, 187(2): 53–62, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22511     

Lantibiotics Produced by Oral Inhabitants as a Trigger for Dysbiosis of Human Intestinal Microbiota

Lantibiotics are a type of bacteriocin produced by Gram-positive bacteria and have a wide spectrum of Gram-positive antimicrobial activity. In this study, we determined that Mutacin I/III and Smb (a dipeptide lantibiotic), which are mainly produced by the widespread cariogenic bacterium Streptococcus mutans, have strong antimicrobial activities against many of the Gram-positive bacteria which constitute the intestinal microbiota. These lantibiotics also demonstrate resistance to acid and temperature. Based on these features, we predicted that lantibiotics may be able to persist into the intestinal tract maintaining a strong antimicrobial activity, affecting the intestinal microbiota. Saliva and fecal samples from 69 subjects were collected to test this hypothesis and the presence of lantibiotics and the composition of the intestinal microbiota were examined. We demonstrate that subjects possessing lantibiotic-producing bacteria in their oral cavity exhibited a tendency of decreased species richness and have significantly reduced abundance of the phylum Firmicutes in their intestinal microbiota. Similar results were obtained in the fecal microbiota of mice fed with S. mutans culture supernatant containing the lantibiotic bacteriocin Mutacin I. These results showed that lantibiotic bacteriocins produced in the oral cavity perturb the intestinal microbiota and suggest that oral bacteria may be one of the causative factors of intestinal microbiota dysbiosis.     

Intention-Sensing Recipe Guidance via User Accessing to Objects

Sensing the intention of a user’s forthcoming action is a necessary function for systems that assist human physical activity. In this article, a strategy for recipe guidance systems that can predict the forthcoming intended subtask in a cooking task is investigated. The focus is on user accessing objects, that is, touching and releasing objects. Touching can indicate the start of the forthcoming subtask and releasing can indicate the end of the task. The main difficulty lies in the fact that humans may move objects because they are in the way and use cooking tools that are unanticipated by an assistive system. In such cases, the accessed object should not indicate the forthcoming subtask. A method is proposed to track the progress of a task based on the object access history. This enables to eliminate object accesses that are out of context. Simultaneously, the method predicts the forthcoming subtask based on a combination of progress and materials rather than tools and materials. Then, a guidance system that runs as a web service is developed. In experiments, real cooking activities navigated by this system are observed. The Wizard of OZ method is utilized to simulate a system that detects object accesses. The experimental results show that 73.6% accuracy is achieved in the selection of the displayed information. This result supports the use of “access to objects” realize effective intention-sensing systems.     

Ultraviolet-emitting ZnO thick layer grown by thermal oxidation with gallium

The Zn O layer with thickness of 1.6 μm in Zn O/Zn Ga2O4 composite structure was grown by the thermal oxidation of Zn S substrate with gallium. The optical property of the Zn O thick layer was investigated by time-resolved photoluminescence. A single UV emission around 375 nm with short lifetime was observed at room temperature while the visible emission was absolutely quenched. The UV emission band was composed of the neutral donor bound exciton(D0X) and donor-acceptor pair(DAP) emission peaks with large full-width at half-maximums(FWHMs) at 3.367 and 3.318 e V, respectively, at 10 K. However, the intensity of the D0 X emission was stronger than that of the DAP emission at measuring temperatures of 10–300 K.     

Effect of oral γ-aminobutyric acid (GABA) administration on sleep and its absorption in humans

Food Science and Biotechnology - The effects of γ-aminobutyric acid (GABA) on sleep and its levels in blood after oral administration were investigated in humans. A randomized, single-blind,...