LSPIV implementation for environmental flow in various laboratory and field cases

Large-Scale Particle Image Velocimetry (LSPIV) is an extension of a quantitative imaging technique to measure water surface velocities using simple and inexpensive equipment. This paper describes the implementation of imaged-based LSPIV in eight different environmental flow and hydraulic engineering applications for the investigation of complex configurations with and without sediment transport (bed and suspended loads). These applications include the investigation of sedimentation in shallow reservoirs, run-of-river hydropower plants, side weirs used to control bank overflow, flow fields in different spillway configurations with and without Piano Key Weir (PKW), oil spills with flexible and rigid barriers, groin fields, river confluence, and sediment flushing in reservoirs. The paper summarises some special problems encountered in such study cases. The selection and adjustments of the parameters to solve them properly were examined. The potential of LSPIV to measure surface flow velocities in the context of river and dam engineering projects is shown. Despite significant variations of natural and artificial illuminations and seeding tracers in the laboratory, field, wind, and water surface elevation, LSPIV was applied successfully to obtain velocity measurements. LSPIV has proven to be a reliable, flexible, and inexpensive flow diagnostic tool that can be employed successfully in many engineering applications.     

Antitermitic Activities of Abietane-type Diterpenes from <Emphasis Type="Italic">Taxodium distichum</Emphasis> Cones

Eight known abietane-type diterpenes were isolated from the weak acidic fraction of the n-hexane extract from cones of Taxodium distichum, one of the extant, living fossil conifers. They were identified as 6,7-dehydroroyleanone (1), taxodal (2), taxodione (3), salvinolone (4), 14-deoxycoleon U (5), 5,6-dehydrosugiol (6), sandaracopimaric acid (7), and xanthoperol (8). The structures of these compounds were determined by comparison of NMR spectral data with published data. The antitermitic (termicidal and antifeedant) activities of the compounds 1–8 against the subterranean termite, Reticulitermes speratus Kolbe, were evaluated. Compounds 1 and 3 showed potent termicidal activity, and 5 and 8 showed potent antifeedant activity. Compound 1 was found to be one of the representative bioactive compounds in the n-hexane extract of T. distichum cones. Compounds 1–8, with the exception of 7, were oxides of ferruginol (9). Therefore, the presence of various oxidation forms of the abietane-type structure reflects their various bioactivities.     

Fabrication and electrical characterization of 15% yttrium-doped barium zirconate—nitrate freeze drying method combined with vacuum heating

We applied a nitrate freeze-drying method to obtain a fine synthesized powder of 15% yttrium-doped barium zirconate. Fine 15% yttrium-doped barium zirconate powder of particle size about 30 nm was obtained by synthesizing at 500 °C in vacuum from a powder mixed by the nitrate freeze-drying method. However, we could not obtain such fine powder by synthesizing in air. Using the powder synthesized in vacuum, large and homogeneous grains of 15% yttrium-doped barium zirconate were easily obtained after sintering. Then, the bulk and grain boundary resistance were evaluated by AC 2-terminal measurement of sample in the form of bar and pellet and DC 4-terminal measurement of bar-shape sample. The grain boundary resistance was not inversely proportional to the grain size as theoretically expected. We concluded that specific grain boundary conductivity varies with samples. Some impurities, evaporation loss of barium oxide and/or other unexpected reasons might affect the grain boundary resistance in 15% yttrium-doped barium zirconate.     

Structural optimization of gas diffusion electrodes loaded with LaMnO3 electrocatalysts

In this study, gas diffusion electrodes (GDEs) with two catalyst layers were fabricated and tested for their electrode performance for oxygen reduction in an alkaline solution. The LaMnO₃/carbon black catalyst layers were fabricated using a reverse micelle method to finely disperse the LaMnO₃ particles onto the carbon matrices, for which commercial Ketjen Black (KB) (1270 m² g⁻¹) and Vulcan XC-72R (VX) (254 m² g⁻¹) were used. The three-layer-structured GDE with the two LaMnO₃/KB and LaMnO₃/VX catalyst layers exhibited a superior oxygen reduction activity when compared to that of a conventional GDE with only one LaMnO₃/KB catalyst layer. Pore size distribution and gas permeability measurements revealed that the LaMnO₃/VX layer was more porous and had higher gas permeability than the LaMnO₃/KB layer. These results suggest that the intermediate layer of LaMnO₃/VX can efficiently supply oxygen to reaction sites dispersed in the LaMnO₃/KB and LaMnO₃/VX catalyst layers, which consequently leads to an improvement in the electrode performance.     

Fundamental study on the development of a surgical device for polymer‐tissue adhesion using vibration damping of polymeric materials

To develop a surgical handheld device that can be used to promote polymer‐tissue or tissue‐tissue adhesion, we designed a polymeric clamp material (PCM) that self‐heats as a result of vibration. By using the PCM, heat can be applied to the target biomaterial and the tissue simultaneously. The optimal temperature is high enough to promote adhesion but low enough to retain the native tissue's integrity. Furthermore, the PCM should not adhere to the target polymer or the native tissue. We found that the temperatures of fluorinated polymers, such as poly(tetrafluoroethylene) (PTFE) and perfluoroalkoxy (PFA), increased within 60 s to 150°C and maintained a stable temperature thereafter. The heat that was transferred to the saucer attached to the potential PCM was slightly above 100°C, a temperature that promotes adhesion but does not damage the native tissue. No deformation or melting was observed during the experiment, indicating that PTFE or PFA possess desirable PCM characteristics for use as a surgical heating device. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2532–2537, 2013     

Chemical Expansion and Change in Lattice Constant of Y‐Doped BaZrO3 by Hydration/Dehydration Reaction and Final Heat‐Treating Temperature

Knowledge of thermal behavior of electrolyte is important for fuel cell fabrication. In this study, using high‐temperature X‐ray diffraction analysis (HT‐XRD) and thermo‐mechanical analysis (TMA), a systematic investigation of lattice constants was performed on Y‐doped BaZrO₃, which is a promising candidate for electrolyte in protonic ceramic fuel cells. The results revealed that a chemical expansion was observed between 300°C and 450°C during the heating process in HT‐XRD, and was attributed to the dehydration of BZY. Furthermore, it was found that the lattice constants of the samples doped with Y, Sm, Eu, and Dy were larger for the ones finally heat‐treated at 1600°C for sintering than those heat‐treated at 1300°C for synthesizing. The similar behavior was not observed in Sc‐doped samples.     

Ultrastructural characterization of surface‐induced platelet activation on artificial materials by transmission electron microscopy

Platelet adhesion is one of the most pivotal events of blood clotting for artificial surfaces. However, the mechanisms of surface‐induced platelet activation have not been fully been elucidated or visualized so far. In this study, we attempted to observe the internal structures and adhesion interfaces of human platelets attached to artificial surfaces by transmission electron microscopy (TEM) during the platelet activation process. We prepared observation samples by a conventional embedding method using EPON 812 resin. The sectioning was sliced perpendicular to the a‐platelet/material interface. Observation by TEM indicates that internal granules coalesce in the center of the platelet accompanied by pseudopodial growth in the early stage of platelet activation. Pseudopodia from a platelet attach to the material interface not along a plane but at a point. In addition, along with the process of platelet activation, the gap between the platelet membrane and the material surface at the interface disappeared and a‐platelet/material adhesion became much tighter. In the fully activated platelet stage, the platelet becomes thinner and tightly adheres to the substrate. As a result of comparative observation of an adherent platelet on polycarbonate (PC) and on amorphous carbon (a‐C:H), it was found that internal granules release was inhibited more remarkably on a‐C:H coating rather than on PC. Despite numerous technical difficulties in preparing sectional samples, such a study might prove the essential mechanism of biomaterial‐related thrombosis, and it might become possible to modify the surfaces of materials to minimize material‐related thrombosis. Microsc. Res. Tech. 76:342–349, 2013. © 2013 Wiley Periodicals, Inc.     

Isolation of Multipotent Nestin-Expressing Stem Cells Derived from the Epidermis of Elderly Humans and TAT-VHL Peptide-Mediated Neuronal Differentiation of These Cells

A specialized population of cells residing in the hair follicle is quiescent but shows pluripotency for differentiating into epithelial-mesenchymal lineage cells. Therefore, such cells are hoped to be useful as implantable donor cells for regenerative therapy. Recently, it was reported that intracellular delivery of TAT-VHL peptide induces neuronal differentiation of skin-derived precursors. In the present study, we successfully isolated multipotent stem cells derived from the epidermis of elderly humans, characterized these cells as being capable of sphere formation and strong expression of nestin, fibronectin, and CD34 but not of keratin 15, and identified the niche of these cells as being the outer root sheath of the hair follicles. In addition, we showed that TAT-VHL peptide induced their neuronal differentiation in vitro, and confirmed by fluorescence immunohistochemistry the neuronal differentiation of such peptide-treated cells implanted into rodent brains. These multipotent nestin-expressing stem cells derived from human epidermis are easily accessible and should be useful as donor cells for neuronal regenerative cell therapy.     

A fuzzy‐based control method for smoothing power fluctuations in substations along high‐speed railways

The use of superconducting magnetic energy storage (SMES) for smoothing power fluctuations in a railway substation has been discussed. This paper proposes a smoothing control method based on fuzzy reasoning for reducing the SMES capacity at substations along high‐speed railways. The proposed smoothing control method comprises three countermeasures for the reduction of the SMES capacity. The first countermeasure involves modification of rule 1 for smoothing out the average electric power to its average values. The other countermeasures involve the modification of the central value of the stored energy control in the SMES and revision of the membership function in rule 2 for the reduction of the SMES capacity. The SMES capacity in the proposed smoothing control method is reduced by 49.5% compared to that in the nonrevised control method. Computer simulations confirm that the proposed control method is suitable for smoothing out power fluctuations in substations along high‐speed railways and for reducing the SMES capacity. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 179(2): 35–43, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21175     

Influence of Grounding Resistance Connecting to Surge Arrester on Effectiveness of Lightning Protection Caused by Direct Hit for Power Distribution Lines

In Japan, the grounding resistance of surge arresters (Arrs) for the lightning protection of power distribution lines is generally maintained below 30 Ω. Therefore, electric power companies have been spending large amounts of money on the construction and maintenance of low grounding resistances. In this paper, the influence of grounding resistance on lightning protection measures for power distribution lines with both a ground wire (GW) and Arrs is investigated by EMTP analysis and experiments. These results showed that even if the grounding resistance of Arrs becomes high, the effectiveness of lightning protection is hardly decreased. The results also indicated that it is more important for constructing a rational lightning protection system to install a large number of lightning protection devices on power distribution lines than to lower the grounding resistance of Arrs. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 179(3): 10–22, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21280