In Aomori Prefecture, several problems have become major issues. Namely, those of individuals’ insufficient environmental awareness (open burning in agricultural work including apple cultivation, etc.), the lowest life expectancy in Japan (Aomori is the prefecture with the lowest average life expectancy for both men and women nationwide), and the seriousness of the economic situation (individual incomes in Aomori are the lowest in the country). Separate solutions have been adopted for each of these problems, but the effectiveness of such solutions is doubtful. Each problem is conceivable in itself as both a cause and an effect. So we need to solve them all simultaneously. Each previous solutions had common goals of expanding social education. Therefore, our research aims to create a mechanism to solve the above problems at the same time by creating necessity to participate in social education, researching apple cultivation which is representative agriculture in Aomori prefecture. The mechanism comprises three systems. The “LCA / Business Support System”, the “Traceability System” and the “Education Point Payment System”. For the present study, we created a tool for inputting work data and running life cycle assessments (LCAs) to act as the LCA / Business Support System, and then carried out a data entry and LCA test-run. As a result, we confirmed that this tool can be constructed inexpensively and that the user can easily ascertain the situation of environmental burden and work which needs improvement. This also confirms the possibility of using this mechanism to create motivation for change by necessity.
Graphite particles were irradiated by platinum (Pt) ions using a coaxial arc plasma gun (CAPG), and the atomic structure of the irradiated graphite particles was analyzed by high-resolution transmission electron microscopy (HRTEM) and scanning transmission electron microscopy (STEM) coupled with electron energy loss spectroscopy (EELS). The matrix of graphite particles was found to be disordered by the Pt ion irradiation, which was also confirmed by the STEM-EELS analysis. The crystal structure of graphite particles became more heavily disordered with increasing the particle size of Pt. It is suggested that the input energy of CAPG and dose of Pt ions must be optimized to deposit crystalline Pt nanoparticles without destroying the atomic structure of graphite particles.
Tensile strength at each accumulative probability of strength (Pf) was obtained for 28mass% carbon fibers (CF) reinforced thermoplastic polypropylene (PP) with and without sizing epoxy film on the fibers prior to making composites (CFRTP) of three cross CF cloth sheets and four PP matts, layer by layer. The sizing film covered on CF apparently improved the tensile strength. Namely, an effect of the sizing epoxy film covered on carbon fiber apparently strengthened the CFRTP. It could be explained by the increasing resistance to pull-out fibers with large friction force because the adhesive sizing film probably increased the interface contact atom pairs of CF and PP. The PP was distorted and twisted polymers more than that of straight polymers of polyethylene, and was probably generated the spontaneous nano-scale rough interface against CF.
In order to use diopside as a phosphorous absorption material which does not require a decarboxylation step, its phosphorus removal ability was evaluated by dipping it in an aqueous solution containing 40.0 to 200 mg/L of carbonic acid and 2.50 mg/L of phosphorus. When diopside was immersed in phosphate solutions containing a low concentration of carbonic acid, phosphorus concentration was under 0.46 mg /L. However, in a solution containing over 150 mg/L of carbonic acid, even after mixing, phosphorus concentration was over 0.50 mg/L. On the other hand, when 40.0 mg/L of calcium was added to the solution containing 200 mg/L of carbonic acid, phosphorus concentration was 0.24 mg/L and well adsorbed. Calcite and magnesian calcite were newly precipitated in the residue of the aqueous solution after the treatment. In addition, by energy dispersive X-ray spectroscopy surface analysis it was possible to confirm the presence of phosphorus on the diopside surface. Elution of magnesium from diopside may accelerate the formation of soluble magnesian calcite and may prevent the precipitation of insoluble calcite, the cause of phosphorus suppression. Thus, diopside could be used as a phosphorus absorption material capable of adsorbing phosphorus even in an aqueous solution containing carbonic acid.
Nanoparticles have gained immense attention as drug carriers in biodegradable drug delivery systems. Particle size is one of the most important characteristics of nanoparticles. It determines the in vivo distribution and targeting ability of nanoparticle drug delivery systems. In this study, we developed a surfactant-free method for the preparation of poly(lactic acid)/hydroxyapatite (PLA/HAp) particles for drug delivery applications. PLA/HAp particles decompose safely in the body. In this study, we investigated the effect of PLA content and ionic concentrations on the particle size of PLA/HAp particles. The particle size of PLA/HAp particles with different PLA contents and ionic concentrations was determined by SEM. The results showed that the PLA content played a crucial role in increasing the particle size of the PLA/HAp particles.
An aqueous solution with doubled ion concentration of simulated body fluid (2.0SBF) was prepared. In order to impart hydroxyapatite formation ability to polylactic acid (PLA) matrixes, the PLA fabric cloth and foam were immersed in 2.0SBF and the pH value was increased. By this treatment, apatite nuclei were precipitated on the PLA matrixes. By immersing in physiological SBF, hydroxyapatite layer was formed on the surface of the PLA matrixes and hydroxyapatite formation ability was successfully performed.
Roughened surface was formed on the surface of Co-Cr-Mo-W alloy substrate by applying doubled sandblasting method using silicon carbide grinding particles with 14 μm and subsequently 8 μm in average diameter. In order to impart hydroxyapatite formation ability to the Co-Cr-Mo-W alloy, the substrate was immersed in simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma adjusted at higher pH in comparison with those of physiological SBF and heated. By this treatment, apatite nuclei were formed on the Co-Cr-Mo-W alloy. By immersion in physiological SBF, hydroxyapatite covered whole surface of the substrate within 3 days and high hydroxyapatite formation ability was performed. The formed hydroxyapatite layer was adhered by mechanical interlocking effect between the substrate with roughened surface and the hydroxyapatite layer.
In this study, we aimed to combine good mechanical properties of bearing grade PEEK with bioactivity for more attractive implant material. We succeeded in providing bioactivity for bearing grade PEEK by the following three steps. First, we formed micropores on bearing grade PEEK by the immersion in sulfuric acid. Second, the bearing grade PEEK plate with micropores was exposed to O2 plasma by glow discharge for providing hidrophilicity. Finally, Apatite Nuclei (AN), precursors of hydroxyapatite (HAp), was deposited on the substrate. This bioactive bearing grade PEEK was covered with HAp within 1 d immersion in SBF. It was suggested that AN were essential for providing bioactivity to bearing grade PEEK in the present method. The adhesive strength between induced HAp layer and bearing grade PEEK was obtained due to mechanical interlocking effect of micropores formed by sulfuric acid treatment. In addition, it was suggested that the combination of sulfuric acid treatment and subsequent glow discharge treatment was effective for good adhesive strength between induced HAp layer and bearing grade PEEK plate.
We fabricated hydroxyapatite microcapsules encapsulating γ-Fe2O3 particles by biomimetic method using Apatite Nucleus and SBF. In general, hydroxyapatite adsorbs many types of biomolecules like enzyme on its surface. In the present study, to examine enzyme immobilization property of the microcapsules, we immobilized seven types of enzymes with different isoelectric point in phosphate buffered saline (pH 7.40). From results of material analyses, we successfully fabricated hydroxyapatite microcapsules encapsulating γ-Fe2O3 with lower crystallinity than that of stoichiometric hydroxyapatite. In comparison with monoclinic hydroxyapatite, the microcapsules adsorbed more enzymes due to the larger specific surface area. As enzyme in the buffer was moderately charged, immobilization efficiency showed the highest value. It is suggested that immobilization efficiency was affected by pI of enzyme and that enzyme immobilization occurred by not only electrical double layer interaction but also ion interaction and other interactions.
We studied sol-gel processing of thick and crack-free TiO2 films to synthesize structural color materials. The viscosity of the alkoxide-based precursor sols was stabilized by the addition of acetyl acetone, which improved control of the spin coating thickness. We used a TiO2/SiO2/TiO2 triple-layer structure and second-order reflection conditions to produce structural coloration. This design yielded a sharp spectral peak and bright coloration; however, a TiO2 layer with a thickness greater than 200 nm was required, which is much thicker than that required for the first-order of reflection. Crack formation in the thick films was suppressed by the addition of ethyl cellulose to the precursor sols. As a consequence, color-tuned TiO2/SiO2/TiO2 films were successfully prepared and exhibited various bright colors in the visible light wavelength range, including two primary colors of light, namely blue and green. Green coloration from flake-shaped particles was also demonstrated.
The close-packed structures of spherical microdomains in polybutadiene-poly(ε-caprolactone) diblock copolymer (PB-PCL) / polybutadiene (PB) were investigated using small angle X-ray scattering with synchrotron radiation. Two kinds of homopolymers,PB1k (Mn = 900 g/mol) and PB2k (Mn = 1700 g/mol), were used. In the PB-PCL/PB1k blend sample with a weight fraction of added homopolymer (φPB1k) of 40 wt%, the hexagonal close-packed lattice (HCP) was formed, while face-centered cubic lattice (FCC) was observed in the sample with φPB1k ≥ 56. In PB-PCL/PB2k with φPB2k = 50 wt%, spheres arranged in non-equilibrium liquid-like packing. The HCP lattice structure appeared in the blend with φPB2k = 56 wt%, whereas the FCC lattice structure was observed for φPB2k = 67 wt%. It was found that the lattice changed from HCP to FCC with increasing amount of homopolymers. The concentration dependence of radius of spherical micelles (Rc) was also investigated. The size of R in PB-PCL/PB2k was larger than that in PB-PCL/PB1k irrespective of weight fraction of homopolymer. In addition, concentration dependence of Rc was almost constant in PB-PCL/PB2k, but R of PB-PCL/PB1k was decreased with increasing φPB1k.
We prepared luminescent Si nanoparticles via the Mg reduction of SiO2 particles extracted from rice husks, and investigated their optical properties. The formation of Si powder after Mg reduction and post HCl treatment was confirmed by the absorption of surface Si–H bonds. Weak red, near-infrared photoluminescence (PL) was observed for the Si particles. The luminescence intensity increased by approximately 400 times after HF/HNO3 etching. The PL lifetime of the Si particles after HF/HNO3 etching decreased with decreasing wavelength, indicating that the PL was caused by the recombination of hole–electron pairs in the nanometer-sized Si particles.
(1-x)(Na0.50K0.45Li0.05)NbO3－xCa(Zr0.50Ti0.50)O3 (NKLN－CZT, x = 0－0.08) powders were synthesized by a malic acid complex solution method, and NKLN－CZT solid solutions were then fabricated using a conventional solid-state reaction technique. The piezoelectric properties of the resulting materials were measured, and the sample with x = 0.02 was found to exhibit a maximum longitudinal piezoelectric coefficient and radial electromechanical coupling factor of 238 pC/N and 35%, respectively. Based on both its piezoelectric properties and the results of a local structural analysis using high-energy X-ray diffraction, this sample has potential for use as a high-temperature, high-performance, lead-free piezoelectric material.
The structural and electrical properties of Nd0.6Sr0.4FeO3-δ (NSFO) have been investigated in the bulk ceramic and thin film forms. Although NSFO bulk ceramic exhibits p-type conduction, the NSFO thin film changes to n-type conduction. The NSFO thin film has larger lattice distortion than the bulk ceramic due to the lattice mismatch between NSFO and Al2O3 substrate. The low crystal symmetry of the thin film is reflected in the electronic structure measured by soft-X-ray spectroscopy. The electrical conductivity of the NSFO thin film with 112 nm thickness is higher than that of the bulk ceramic at above 850 K. This originates from the change of electron number for eg-subband in the Fe 3d valence band with the lattice distortion.
The surface electronic structure of as-deposited and post-annealed La0.67Sr0.33MnO3 (LSMO) thin films on SrTiO3 (100) substrates has been studied by soft-X-ray spectroscopy. The crystal lattice reduces by post-annealing in air at 1100 ℃. The electrical resistivity also decreases by the post-annealing. These thin films has the mixed valence states of Mn3+ and Mn4+. The valence band near the Fermi level (EF) consists of the eg↑ and t2g↑ states of Mn 3d. The density of state at EF is higher in the post-annealed LSMO thin film. These results directly indicate that the change of the Mn valence state is closely related to the electrical resistivity and Mn 3d electron number of LSMO thin film at the surface state.
We have investigated synthesis conditions and magnetic properties of Sr2Fe2+2Fe3+12O22 (Sr2Fe2Y). The main Y-type phase was observed for the sample synthesized with the initial composition of Sr:Fe2+:Fe3+=1.5:2:8 sintered at TS=1200℃ and PO2=10 Pa. The Curie temperature of Sr2Fe2Y was 643 K. The magnetization was 45.0 Am2/kg at T= 5 K and μ0H=7 T. The difference in magnetization from the ideal collinear spin arrangement of Sr2Fe2Y is due to the existence of a minor Fe3O4-like spinel phase. The yield of Sr2Fe2Y phase was estimated to be 83 wt.%, suggesting successful synthesis of the Sr2Fe2Y hexaferrite.
Corona discharge is an electrical discharge in air. An electrostatic precipitator is one of the applications using the corona discharge. In the corona discharge area of the electrostatic precipitator, an ionic wind is occurs with moving ions, additionally, charged particles drift by a Coulomb force from the high voltage wire electrode to the grounded plate electrode. When the grounded electrode is made of woodceramics instead of a stainless steel electrode, it is considered that the adsorption of gases is improved, then the fine charged particles trapped on the grounded electrode surface increase due to the porous structure and high resistivity of the woodceramics. The high resistivity electrode prevents the collected particles on the electrode releasing the charge. As a result, when the grounded electrode is made of woodceramics instead of the stainless steel electrode, the discharge current of the woodceramics and that of the stainless steel electrode have the same characteristics. The particle collection efficiency of the woodceramics electrode was higher than that of the stainless steel electrode in the particle size range from 0.3 to 5.0 μm. Additionally, it was observed that these particle collection efficacies were influenced by the initial particle concentration.
In this research, we examined a method that separates and recovers metals from pulverized powder of printed circuit boards (PCBs) contained in discarded personal computers (PCs). It has been reported that more than 80% of valuable metals could be recovered after the following processes of crushing, pH adjustment, and melting. However, as this technique requires an extremely high temperature, it is too costly for practical use at the actual machine level. In particular, a lower cost separation technology is needed for common materials such as Cu, Fe, Ni, Sn and Pb. Instead of the melting process, we apply ferritization process to the PCBs for recovery of common metals by magnetic separation. The PCB slag recovered valuable metals was mixed with several iron oxides powder, and ferritized at a temperature of 1073–1273 K for 10–60 min under atmosphere. Ferritization of FeO–PCB powder was completed in 10 min at 1073 K. The powder collected on the magnetic side had a saturation magnetization of 7.54 emu/g. The largest amount of ferritized PCBs powder was collected by magnetic separation. And, 95mass% of the common metals were recovered.
The adsorption of alizarin (AZ) and alizarin red (AZR) on anodic aluminum oxide (AAO) plates was studied by spectroscopic methods. AAO plates were prepared by anodization of aluminum plates in a 1.8 M sulfuric acid solution. Adsorption studies were carried out by immersing the AAO plates in ethanol solutions of AZ and AZR at different pH values, whereby the color of the solutions changed according to the pH due to protonation/deprotonation. The absorption spectra of AZ in solution and that adsorbed on AAO were different, indicating the formation of AZ-Al3+ complexes with 1:1 stoichiometry by coordination of AZ to the surface of AAO. Similar spectra were obtained for AZR adsorbed on AAO, confirming that AZR is also adsorbed on the surface by coordination and not via electrostatic interactions between the sulfonate group of AZR and the AAO surface. Based on the spectral features of the AZ-adsorbed AAO plates, the possibility of their application in pH sensing is proposed.
Dielectric measurements for 10wt % W/O emulsion samples prepared with various surfactant concentrations between 0 and 10wt % were carried out in the frequency range of 40Hz up to 20GHz at room temperature during 2 hours at 15-minute intervals. Three distinct relaxation processes such as an electrode polarization in the kHz region, an interfacial polarization originated from ion dynamics on the interface of water and oil in MHz region, and an orientation polarization of oil molecules in the 100MHz region were observed. The relaxation time and relaxation strength of the interfacial polarization increased with time. These time dependences of the relaxation time and strength become more moderate with increasing surfactant concentration. In addition, these time dependences also suggest increasing water-droplet size and reflect stability of the dispersion system. In this study, all measurements were carried out with a cell type electrode, in which the water content was considered to be larger at the bottom of electrode, and the ε∞ value can be an indicator of the water content. The 1% surfactant W/O emulsion samples did not show an increase in the water content, but the relaxation time for the interfacial polarization increased much. This is an evidence of increasing water-droplet size, because the relaxation time of interfacial polarization is considered to reflect spatial scale of interface of water droplets. These results indicate a change in the W/O emulsion structure with time by dielectric spectroscopy.
A porous carbon material made from rice bran (rice bran carbon: RBC) has been developed for the effective utilization of defatted rice bran. RBC has some unique mechanical properties, such as a low Young’s modulus, low coefficient of friction, and high abrasion resistance. Therefore, RBC is used as a sliding element. For example, it can be applied to bearings such as wave-power generation or wind-power generation under the condition of such as beach exposure or seawater immersion. However, RBC contains some deliquescent components and thus has large hygroscopic expansion and a large reduction in mechanical strength under wet and aquatic conditions. Also, a white precipitate forms on the surface of RBC when it is immersed in seawater. In this study, the white precipitates that form on the surface of RBC during seawater immersion was analyzed. The immersion test was carried out with reference to JIS-R-1647. The immersion time was set at under the maximum of 1000 h, and precipitates generated on the surface of the test piece over time were obtained. MgK(PO4)•H2O precipitates were formed on the surface of RBC from three reactants, namely, phosphorus and potassium ions contained in RBC and magnesium ions in seawater.
2-Hydroxy-1-((2-(pyridin-2-yl)hydrazono)methyl)tryptanthrin (T2OH1CH=N-NH-Pyri) was synthesized and applied as a fluorescent chemosensor for metal ions. We investigated the metal-ion recognition of T2OH1CH=N-NH-Pyri in separate Li+, Na+, K+, Mg2+, Ca2+, Ba2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Ag+, Zn2+, Cd2+, Al3+, and Pb2+ acetonitrile solutions. Li+, Na+, K+, Ca2+, Ba2+, and Ag+ had no effect on the shape and intensity of the fluorescence spectrum of the chemosensor. T2OH1CH=N-NH-Pyri formed a 1:1 complex with Mg2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Al3+, and Pb2+. The fluorescence intensity of the sensor increased for Mg2+, Zn2+, Cd2+, Al3+, and Pb2+, and decreased for Fe2+, Fe3+, Co2+, Ni2+, and Cu2+.