Boron-doped diamond hollow fiber wool (BDD-HFW) was fabricated as a porous monolithic conductive diamond material. BDD-HFW was obtained by deposition of BDD onto a quartz wool substrate followed by removal of the substrate by chemical etching. Scanning electron microscopy observations confirmed that BDD-HFW consisted of BDD hollow fibers with diameters of several micrometers. The double-layer capacitance of a BDD-HFW electrode was estimated to be ca. 13 Fg−1 from cyclic voltammetry measurements in an aqueous electrolyte.
The purpose of this work is to study the electric properties of graphite and the synthesis of a few layers graphite intercalation compounds (GIC). First, intercalation of Li between graphite layers was done by soaking the substrates into a 20 ml n-butyllithium solution. Second, intercalation of FeCl3 into the graphite was done by heating FeCl3 powder and graphite in the quartz tube. For Li intercalation, the appearance of an extra Bragg reflection at 23.7º indicates that Li atoms were intercalated between the graphene sheets in the specimen we grew. For FeCl3 intercalation, the (00l) Bragg reflection was caused by the FeCl3-GIC. Probably Iron Chloride was intercalated in graphite. In the Raman spectra of graphite and FeCl3-GIC, the G, D and 2D peaks were confirmed. Additional peaks only in the specimen of FeCl3-GIC were observed at 1605 cm-1 and 3415 cm-1. It is speculated that the peak is related to the intercalation of FeCl3 into the graphite.
The effects of the Ni thickness in the newly developed Ni/Fe/Al multi-layered catalyst films on the growth structure of the Multi-walled carbon nanotubes (MWNT) by catalytic thermal CVD were investigated. The density, length and diameter of the MWNT forests were successfully controlled by the Ni thickness in Ni/Fe/Al multi-layered catalyst films. The AFM surface morphology of the Ni/Fe/Al multi-layered catalyst films revealed that the additional Ni thin films on the Fe/Al multi-layered films prevented the agglomerations of Fe catalyst resulting in the growth of the high-density, long-length, and uniform MWNT forest.
Poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT/PSS) with various PSS composition ratios (α) was synthesized by oxidative polymerization and particle size distribution and zeta potential of the resulting colloidal gel particles were investigated by means of a dynamic light scattering technique. It was found that mean volume diameter of the PEDOT/PSS colloidal gel particles were 400-600 nm at α = 1～6, which drastically decreased to ～10 nm at α = 8～15. On the other hand, zeta potential was about -80 mV regardless of the composition ratio. The electrical conductivity of the PEDOT/PSS cast film measured by a four-point method attained as high as 263 S/cm at α = 3.
Dielectric measurement of food meat in various states was performed in the frequency of 100 Hz - 1 MHz, in order to clarify molecular mechanism of the dielectric relaxation process observed in human body. Nature of the relaxation process for the meat changes by changing state of meat. The relaxation process around 100 kHz in various meats is due to the internal facial polarization relating to the ion diffusion.
Time Domain Reflectometry (TDR), Nuclear Magnetic Resonance (NMR), and Molecular Dynamics (MD) simulation were employed to characterize water structures in protein-water mixtures. Dielectric relaxation of water observed by TDR showed broadening of the relaxation time distribution reflecting typical slow dynamics of the water structures in dispersed systems. Water structures of a variety of proteins also can be assessed by the fractal analysis. Corresponding to the slow dynamics, the translational diffusion coefficient of water molecules observed by NMR became smaller as protein concentration increased. We also found an optimal condition in MD simulations of water. Without the combination of these complementary techniques, comprehensive understanding of dynamic structures of water in protein-water mixtures cannot be obtained.
In this research, encapsulation of Shewanella oneidensis MR-1 in the phospholipid polymer hydrogel and electrochemical property of the hydrogel with immobilized shewanella was investigated. Cytocompatible and electron transfer mediated polymer based on the water-soluble phospholipid polymer, poly(2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate (BMA)-co-p-vinylphenylboronic acid (VPBA)-co-vinylferrocene (VFc)) (PMBVF) was synthesized by conventional radical polymerization method. Shewanella which have the ability to generate and transfer extracellular electron without any external mediator, have significant potential on the fabrication of microbial fuel cell. The water-soluble PMBVF was dissolved in the cell culture medium containing shewanella cells. Poly(vinyl alcohol) (PVA) solution was added to the PMBVF solution with gently mixing, in which case, a reversible PMBVF/PVA hydrogel with encapsulated shewanella was obtained. The viability of the encapsulated shewanella was calculated by the fluorescence microscopy. The electrochemical property of the PMBVF/PVA hydrogel containing shewanella was measured by cyclic voltammograms (CV) and amperometric i-t curve. PMBVF/PVA hydrogel can provide mild environment for the shewanella and maintain the cellular function for longtime. The generated current was higher than that cultured with normal medium.
In this study, poly(2-hydroxyethyl methacrylate) (PHEMA) copolymers containing cell-binding peptides (Arg-Gly-Asp-Ser (RGDS), Pro-His-Ser-Arg-Asn (PHSRN) or PHSRNG6RGDS) as graft chains were newly designed and prepared by radical copolymerization of HEMA with various peptide-macromonomers, which were prepared by solid phase synthesis using Fmoc-chemistry. Thin films of these copolymers were prepared on PSt-dishes by spin-coat method and their interaction with NIH/3T3 cells were investigated. Cell adhesive properties onto these copolymer films were found to depend strongly on the type of peptides and copolymer composition. More interestingly, PHSRNG6RGDS segment, at which PHSRN and RGDS epitopes were connected through Gly spacer, showed most effective cell adhesion and spreading properties in the series of PHEMA copolymers. These results should provide useful information to construct novel peptide-based nano-surfaces for the design of artificial extra cellular matrix.
We demonstrated that wettability of metal-dome and polymer-pillar hybrid structured surfaces regulated by difference of dome density. The metal-dome and polymer-pillar hybrid surface was prepared by simple all-wet electroless plating of self-organized honeycomb-patterned porous films, and was composed of three independent components; micro-scaled metal-domes, nano-scaled polymer-pillars, and air pockets. The metal-dome density was changed from 0 to 100% only by temperatures of the catalytic solution before electroless plating. Water contact angles of the hybrid surfaces having different dome density were well conformed to the Cassie-Baxter equation. It was obvious from the results that the Cassie-Baxter equation could be adapted to structural surfaces composed of three components.
There is increasing interest in the synthesis of well-organized silica nanostructures using designed peptides as templates. We have demonstrated an approach to synthesize silica nanofibers by sol-gel condensation of tetramethoxysilane as a silica source on the surface of self-assembled peptide nanofibers. Nonapeptide can undergo self-assembly to form peptide nanofibers and was used as templates for silicification under ambient conditions. Peptide nanofibers were stably entrapped within the silica precipitates through templating. The silica morphology and dimensions remained largely intact even after removal of the template by calcination. These findings clearly indicate that the peptide nanoarchitecture allows us to increase diversity in peptide-templated inorganic material synthesis and mimics the natural biomineralization process by means of facile, chemically synthesizable, and controllable self-assembling peptides. This would be an effective approach to produce bulk amounts of inorganic nanostructures for various applications.
At present, logging residues are scarcely used in Japan. However, studies are being conducted on the use of this resource for wood biomass power generation at various places. In this study, we developed a cost-effectiveness analysis method for wood biomass power generation projects. Applying this analysis method will help in deciding the validity and feasibility of power generation plans using the logging residues as the raw material. The purchase price of electricity by electric company and that of wood chip have a serious influence on the success or failure of the power generation projects using the logging residues.
In the manufacturing process Woodceramics, after impregnating of phenolic resin woody materials swell by phenolic resin. The degree to swell the surface of the material will be so high and the shape of the material after resin impregnation becomes non-uniform. This array state is influenced by the processing conditions and its processing method. In order to produce Woodceramics with high quality, when processing material before burning, it is necessary to process under appropriate processing condition.
In this study, coffee grounds were carbonized through activation with carbon dioxide (hereinafter referred to as CO2) or potassium hydroxide (hereinafter referred to as KOH), and the effects of the respective activation conditions on the pore structures of the carbon obtained were investigated. The specific surface area of the sample carbonized in a CO2 stream at 850˚C was 752 m2/g and that of the sample impregnated with KOH and carbonized was 2549 m2/g when the concentration of KOH was 4.5 M. In the sample carbonized in a CO2 stream, the pores formed were 0.8, 1, and 3.1 nm in size, which were enlarged with the increase in treatment temperature and started to include numerous mesopores. In the sample impregnated with KOH and carbonized, the pores formed were 0.7 nm and 1 to 1.1 nm in size, which were slightly enlarged with the increase in concentration of KOH. It was confirmed that for coffee grounds, activation with KOH had an effect of increasing specific surface area and that CO2 activation had an effect of increasing pore size.
Various food by-products as well as before and after fermentation of fermented feed for dairy cattle in Aomori Prefecture were evaluated. The fermented feeds evaluated were: Aomori-Semi-TMR (AST), Aomori-TMR (AOT), Michinoku-WET (MTW), Aomori-WET (AOW). Food by-products produced in Aomori that are used as ingredients for fermented feeds, i.e. Tofu by-product (TFB), Apple juice pulp (AJP), Soy sauce cake (SSC), Mushroom bed (MRB) and other feed ingredients and food by-products used as ingredient coming from outside Aomori, i.e. Brewers wet grains (BWG), Wheat straw (WHS), Beet pulp (BEP) were also evaluated. In situ studies were conducted on two rumen fistulated Holstein cows using nylon bags containing 5g (as fed basis) of each time point in the ventral rumen of each cow for 3, 6, 9,12 and 24 hours, respectively. Comparison on the in situ rate of disappearance of before and after fermentation of the fermented feeds indicated that DM and NDF were not significantly different while CP was significantly different in AOW (P＜0.05). Comparison on the rumen parameters of before and after fermentation of fermented feeds indicated that DM was significantly different from potential degradable fraction, rapid potential degradable fraction and degradation rate constant (P＜0.05) while CP was significantly different on degradation rate constant (P＜0.05). Before and after fermentation of fermented feeds using food by-products varied in their ruminal DM, CP and NDF degradation.
Many infectious animal diseases that could not be controlled well by vaccination, including foot-and-mouth disease (FMD) and highly pathogenic avian influenza (HPAI), have occurred in many countries, especially across Asia. Materials that can enhance biosecurity in farms are important. In Japan, slaked lime has been used as disinfectant in farms, but it has a toxic effect on animals, as well as humans, and is easy to lose antiviral activity by oxidation. The desirable materials should be safe, cost effective, and long life. Aomori prefecture in Japan is very famous for culture of scallops. The scallop-shells after calcination process become powder and the main content of the powder is calcium oxide (CaO) that has bactericidal effects. Here we demonstrated antiviral activity of scallop-shell powder and its long life of antiviral activity against avian influenza virus (AIV) and goose parvovirus (GPV). Scallop-shell powder could reduce viral titers of AIV and GPV more than 10,000 times to undetectable level within 3 minutes. When the powder was spread on containers or on a chicken farm, its antiviral activity lasted more than 8 months. Scallop-shell powder seems to be a good candidate of materials for enhancement of biosecurity in farms.
The Se-doped SrTiO3 (SrTi1-xScxO3-δ) thin films have prepared on Nb-doped SrTiO3 (100) substrates by RF magnetron sputtering. The thin film deposited at the substrate temperature of 500°C exhibits highly α-axis orientation. The as-deposited thin film consists of grain with a diameter of ～60 nm and smooth surface. The electrical conductivity exhibits hole conduction at low temperature region below 400°C and oxygen ion conduction at high temperature region above 550°C. The activation energy at the low temperature region, which is estimated from the Arrhenius plot of the electrical conductivity, is in a good agreement with the energy separation between the top of the valence band and the Fermi level.
The electronic structures in the surface and bulk states of Y3+-doped BaZrO3 (BaZr1-xYxO3-δ) have been studied by X-ray absorption spectroscopy and soft-X-ray emission spectroscopy. The valence band is mainly composed of the O 2p state hybridized with the Zr 4d state. The conduction band consists of Zr 4d state. The band gap increases with increasing Y3+ concentration, indicating the existence of hole at the top of valence band. Although the Fermi level (EF) of bulk locates at the valence band side, EF of surface locates at intermediate of band gap. These findings may indicate that the band bending effect exists at the surface of BaZr1-xYxO3-δ.
We performed X-ray emission spectroscopy (XES) by using a double crystal spectrometer. Ta-Lα1 and Lα2 emission lines of Ta-related materials of Ta-metal, Ta2O5, LiTaO3, and KTaO3 were measured. XES is one of the most important spectroscopies to make a remarkable progress utilizing third generation synchrotron radiation sources. Here, we discuss some aspects of XES in Ta compounds of recent experimental data. We also discuss an azimuth dependence of partial fluorescence yield spectra (PFY) of a single-crystal KTaO3. The precise measurement by the double crystal spectrometer has revealed a change of the PFY spectrum by changing the crystal orientation, especially in the white line region.
We have investigated the electronic and lattice properties of 48H-BN, 20H-SiC, and 30H-AlN polytypes which are sp3-bonded compounds. Their electronic and lattice properties were calculated using the total energy pseudopotential method based on the local density approximation (LDA). As for AlN polytypes (2H, 3C, 4H, 6H, 10H), we investigated using the total energy pseudopotential method based on the generalized gradient approximation (GGA) for comparison with the LDA results. 48H-BN has huge number of possible polytype structures and we chose one polytype structure as “24.24” (Zhdanov notation). “24.24” is not “2424”, which means twenty-four “+” and twenty-four “-” symbols in the Hägg notation. We treat three polytype structures of 20H-SiC as “33322322”, “33332222”, and “32322323” (Zhdanov notations). Their total energies are slightly higher by 0.22 meV/Si2C2 than that of 4H-SiC. Although all the AlN polytypes calculated by LDA have indirect band gaps with the exception of 2H-AlN, 10H-AlN(212212) calculated by GGA has a direct band gap. Its hexagonality is 60 % and “212212” is the Zhdanov notation.
Mechanisms for fabrication of carbon nanomaterials by arc discharge in low-temperature liquid such as liquid helium has been investigated. In particular, bubble behavior at the arc discharge using open and close discharge. When electrodes were closed, small light emission appeared with bubbles. Then, the emission intensity increased rapidly while bubble formation increased slightly. After that light emission disappeared and bubbles decreased. We also captured photographs to characterize the degree of discharge voltage and liquid temperature. The results suggest that all of them were almost same in the liquid helium, liquid nitrogen at the discharge voltage of larger than 20V. When discharge voltage is 10V in superfluid liquid helium, the bubble repeated contraction on low frequency and then it disappeared several seconds afterward. This phenomenon was observed only in superfluid liquid helium, and they dependent on discharge voltage.
Electrospun non-woven fiber mats of cyclodextrin (CD)-immobilized poly(vinyl alcohol) (PVA) could effectively block gene expression mediated by bacterial cell-to-cell communication, quorum sensing (QS). In Serratia marcescens AS-1 as one of the model opportunistic pathogens, N-acyl-L-homoserine lactone (AHL) activates production of antibiotic prodigiosin as a QS signal when the AHL concentration reaches a threshold associated with cell growth. By immersing CD-immobilized fiber mats in the culture broth of S. marcescens AS-1 at beginning of shaking culture, prodigiosin production was successfully intercepted to approximately 30% in the presence of only 0.13 wt% immobilized α-CD or 2-hydroxypropyl-β-CD. It suggested that AHL was almost maintained under the threshold concentration because of forming the inclusion complex with the immobilized CD. By immobilizing CDs on PVA, the inhibitory effects could be enhanced probably by increasing apparent stability constant for CD-AHL complex due to forming hydrogen bonds with hydroxyl groups of the PVA chains. Electrospinning of CD-immobilized PVA provides effective materials for QS inhibition due to trapping AHL signals associated with virulence factor expression in opportunistic pathogens.
The antibacterial activities of some plant powders with magnesium oxide (MgO) were investigated. The antibacterial activities were evaluated using a measuring system with 1% polypepton solutions and plant powder in a desiccator of about 6 liter. Tow antibacterial effects were evaluated by the measurements of CO2 (aerobic bacteria) and mercaptan (anaerobic bacteria) production using a gas-detecting tube. A synergy effect of aerobic bacteria and anaerobic bacteria on the antibacterial activities was observed for phellodendron amurense and rosmarinus officinalis L. with MgO, and green tea as a comparison material. The antibacterial activity of the case of rosmarinus officinalis L. was high and almost the same as that of green tea. The difference between these plant materials was considered to be attributed to the antibacterial activities of the dietary compounds and the contents in rosmarinus officinalis L., phellodendron amurense and green tea. The plant powders with MgO evaluated in this study were useful as the antibacterial material for the organic farming.
8-Hydroxyquinoline ligands 1 and 2 as fluorescent chemosensors for zinc or cadmium ions were synthesized. It is generally difficult to selectively respond to Zn2+ over Cd2+ or Cd2+ over Zn2+. However, ligand 1 selectively responded to Zn2+ over Cd2+, and ligand 2 selectively responded to Cd2+ over Zn2+.