The mechanical strength of ices, especially for the glacier has been studied since 19th century. However, there are few industrial applications such as mechanical processing tools without ice-blast. Because the specific data of mechanical properties for ice are unknown. Therefore, we produced four types of ices which had different clearness using aeration system, and measured the hardness of ices from 77 K to 268 K. Furthermore, the indentation displacements were also measured during the hardness test, so that the Elastic Recovery Ratios of ices were investigated in this study.

View full abstract

We developed the burner that was able to form a cylindrical diffusion flame that had a high curvature, and investigated behavior and the extinction characteristics of the flame. The fuel and the oxidizer used the methane and air respectively. The fuel was diluted with helium. The fuel flows from a center axis to surroundings, and air flows from surroundings toward a center axis. The obtained results are summarized as follows. (1) The developed burner can form the flame that has a high curvature of about 2.5mm in the diameter. (2) The airflow velocity greatly changes the radius of the flame than the fuel flow velocity. (3) The flame luminosity increases when the fuel flow velocity is constant and the airflow velocity is increased. However, the flame luminosity decreases when airflow velocity exceeds a certain value. (4) Flame strength strengthens remarkably as the fuel-flow velocity decreases when the Lewis number of fuel-flow is large. (5) The extinction stretch rate increases as the dilution rate of the fuel decreases, and the flame radius at extinction decreases.

View full abstract

In this paper, we propose a new RL algorithm with Locally Weighted Partial Least Squares (LWPLS) as a function approximator. LWPLS is a class of techniques from nonparametric statistics that is ideally suited to reduce the computational complexity and to avoid numerical problems. The principle of LWPLS is to fit linear models using a hierarchy of univariate regressions along selected projections in input space. The projections are chosen according to the correlation between input and output data, and the algorithm assures that subsequent projections are orthogonal in input space. This new RL algorithm is compared with the usual way of quantizing the state space with grids in a mobile robot navigation task. The results of the extensive simulation demonstrate that our proposed algorithm is clearly outperforming the usual way.

View full abstract

A noble communication algorithms have been proposed, which enables cordless physical monitoring by wireless sensor network. In order to accomplish such monitoring, we have investigated the followings communication algorithms; i) to reduce power dissipation of sensor nodes by making transmission modules into a sleeping state except for transmission phase, ii) to communicate without confusion with multiple sensor nodes by CDMA/CD, and iii) to enlarge communication range with small power wireless communication by a multi-hop communication method. These algorithms have been implemented into an experimental sensor network system consisting of commercially available sensor nodes for evaluation of the communication algorithms. As a result of their evaluations, it was found that power dissipation was reduced to 1/2.5 or working period of two AA alkaline batteries was improved to about 100 hours, that 4 censor nodes could communicate without confusion in the period of 0.5 seconds in the distance of 2m, and that 3-stage multi-hop communications can be accomplished by the delay time of 0.25 second per stage. The proposed algorithms will make a great contribution to realization of practical cordless monitoring system, which can reduce monitoring accidents due to connection cables and mental stress caused by being kept to beds.

View full abstract

Hydrothermal synthesis of TiO_2 nanoparticles from Titanium Tetraisopropoxide (TTIP) -isopropyl alcohol (IPA) solution were carried out with a flow-through apparatus for continuous production and rapid heating of starting solution to supercritical states. The lack of metal oxide solubility induced by low ionic product and dielectric constant achieved fine TiO_2 nanoparticle synthesis by means of nucleus generation at oversaturated condition. Reaction effluent obtained present study at temperatures from 25℃ to 400℃ was dried or filtrated to collect TiO_2 powder. The obtained TiO_2 nanoparticles were characterized as anatase phase by means of X-ray powder diffraction (XRD). Acetaldehyde decomposition profiles of the TiO_2 particles estimated this study showed higher photocatalyst activity than that of the commercial P25 TiO_2 photocatalyst. The transmission electron microscopy (TEM) observation for TiO_2 particles revealed that the particle size were about 15nm, indicating that two-step particle formation at the present equipment for the particle production at supercritical condition.

View full abstract

Heating glycinin at the low ionic strength caused changes in the intensities of the second derivative absorption spectra, but scarcely affected the positions of the peaks and troughs. The spectra indicated that half of tyrosine residues buried in native glycinin was exposed by heating, but tryptophan residues were hardly done. Tryptophanyl fluorescence spectra gave the same information as that obtained by the ultra-violet absorption spectra. Gel filtration of thermal products gave buffer-soluble aggregates as a major component and dissociates. Electrophoresis indicated that the former and the latter consisted of polymerized subunits through disulfide bond, and a monomer and oligomer of acidic subunit, respectively. Difference-derivative absorption spectra indicated that internal hydrophobicity of aggregates was larger than native glycinin, while that of dissociates was conversely smaller. These results suggest that the aggregates were formed with retention of the internal hydrophobic region of glycinin, while the released dissociates were unfolded. Soluble aggregates formed by heating at 0.01 ionic strength would be the soluble macroaggregates before formation of gel network.

View full abstract

Water soluble polysaccharide fractions in rice bran and endosperm showed a potent anticomplementary activity which is responsible for > 99% of the immunological defense system. As compared with water soluble polysaccharide isolated from Glycyrrhiza uralensis, which is a well known medicinal herb, this activity showed higher or similar potency. Water soluble high molecular weight fraction (HMF) in sake had lower activity than intact polysaccharide fractions in rice, suggesting that water soluble polysaccharides were digested on the brewing process.

View full abstract

Macrocyclic glycocluster host molecules (Glu-Host and Lac-Host) which have a strong polar sugar-cluster part interact with many dyes via hydrogen-bonding in a polar solvent. The interactions are detected by UV-VIS spectroscopic change due to host-guest complexation based on hydrogen-bonding. Especially, UV-VIS spectra of all triphenylmethane type dyes such as Brilliant Blue G are changed. Bingding constants of some dyes are able to calculate and these host-guest interactions with Lac-Host are very strong because the binding site in the host is larger than Glu-Host.

View full abstract

The synergistic extraction of rare earth elements (III) has been investigated by a mixture of 2-thenoyltrifluoroacetone (HA) and 3,5-di (2-pyridyl) pyrazole (dpp) as a neutral ligand (S). Large synergistic enhancement was produced owing to the formation of the adduct complexes such as MA_ЗS. Extraction constants of rare earth elements with Htta in the absence and the presence of the neutral ligand were evaluated. The adduct formation constants have a similar value for La to Er and slightly decrease for heavier lanthanoids.

View full abstract

Ab initio density functional theory and quantum mechanics / molecular mechanics (QM/MM) simulation were performed to elucidate catalytic role of water on glyceraldehyde conversion in supercritical water (SCW). The reactant and solvent in a first solvation shell were treated as B3LYP / AUG-cc-pVDZ, and for the solvent molecules we used the flexible SPC-3P water model. A direct participation of water molecule on transition structure reduced activation energy barrier for the reaction. Threshold energy of retro-aldol reaction is the lowest among three pathways. We calculated solvation free energies by means of free energy perturbation method based on solvent-solvent and solute-solvent interactions to explain the effect of solution structure around solute. At high water density condition dehydration pathway is preferred reaction mechanism. However, the retro-aldol reaction mechanism was the preferred reaction pathway at low water densities in SCW. Solvation structure can be catalyzed dehydration reaction, but it can not be catalyzed retro-aldol reaction.

View full abstract

Human hair remaining in sewage sludge compost leads to a deterioration in the quality of the compost. We isolated and characterized the thermophilic microorganisms that decomposed human hair to improve the quality of sewage sludge compost products. The strains were isolated on agar plates after the enrichment culture in hair liquid medium at 50℃ for more than 30 days. The concentrations of amino acids released from keratin or hair were measured to determine the ability to decompose keratin or hair and the extent of hair damage was observed microscopically. We obtained twelve strains which had more efficient hair-decomposing activities at 50℃ than the reported ones. Strain K35 had the highest rate of amino acid production from hair of 77.4mg/L/day. In addition, the effects of strain mixtures and hair disruption on bacterial decomposition are discussed.

View full abstract

Unsaturated triaxial tests were performed to study strength property of undisturbed Hachinohe Loam, volcanic sandy soil under undrained condition. In this study confining pressures were set 0,50, 90 kN/m^2, and initial matric suctions were set 0, 50, 90kPa. As sucton increase, shear stress, at faifure, increased linearly under suction 90 kPa. And the shear strengths at failure which were calculated by the expression proposed by Fredlund, were agreed well with experimental result. We could confirm the history of water retention curve based on soil structure and initial water content under triaxial shear tests.

View full abstract