The basic concept of materials to save mankind sometimes faces to discrepancy with art and politics. "Mottainai" is important. Dreams on the research in computer simulation (molecular dynamics), positron annihilation, high temperature field ion microscopy and transmission positron microscopy are mentioned.

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  Magnesium is the eighth most abundant element in the earth's crust and also the third most commonly used structural metal following steel and Al. Several Al alloys used in automobile, aerospace, nuclear and sports industries are being replaced by Mg alloys due to their high specific strength and good damping capacity. The HCP crystal structure with a limited number of operative slip systems render Mg alloys inherently poorly workable. This drawback has restricted use of these alloys mostly in the as-cast condition. Present research endeavours the world-over are therefore mostly aimed at overcoming this drawback so that Mg wrought alloys find wider application. Just as Mg is a commonly used alloying addition to Al, so also Al in Mg alloys. We have used the processing map technique to study the hot deformation behaviour of Mg-Al alloys. The results show that the addition of Al improves workability at high speeds of deformation, which feature has direct implication to Mg-based component manufacture. It is also found that the tailoring of microstructure through thermo-mechanical processing (TMP) can be achieved as the addition of Al provides a variety of safe processing windows.

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Structure controlled inorganic/polymeric composite micorspheres could be prepared by in-situ formation of inorganic nanoparticle in microgel. Fine titania particle-containing composite microgels were prepared by referring to the methodology to prepare gold nanoparticle-containing microgels. First, amino group was introduced into poly(N-isopropylacrylamide). Then titania precursor anion was invited into the microgel. Precursor was converted in-situ to titania. Titania-containing microgels presented efficient and temperature-sensitive photocatalytic property.

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Micro/nanosizing effect of materials onto biological organism was investigated by both in vitro biochemical cell functional test and in vivo animal implantation test. Dependence of reaction of cells and tissue, and that of bone formation of apatite on particle size were studied. The increase of specific surface area causes the enhancement of chemical reactivity and therefore toxicity in many cases. This is the most usually and easily recognizable and strongest effect in most cases. However there is the other effect which becomes prominent especially for biocompatible materials such as Ti and TiO₂. Stimulus was increased with the decrease of particle size and pronounced below 3 μm by inducing phagocytosis to cells and inflammation to tissue. For the size below 50nm, particles invade into the internal body through the respiratory or digestive system and diffuse inside body. For bone, synthetic hydroxyapatite exhibits excellent osteoconductivity but it is not substituted with natural bone and remains permanently in the body. When the composite with collagen and nanoapatite synthesized in the biomimetic aspects is implanted, resorption of nanocomposite through phagocytosis by osteoclasts and new bone formation by osteoblasts occurred simultaneously after inflammation. Nanocomposite leads to the bone substitutional properties, which resembles the remodeling process in natural bone. Thus nanosizing induces the intrinsic functions of biological organism and results in the conversion of functions such as from biocompatibility to stimulus and from osteoconductivity but non-bone substitutional to bone substitutional properties through biological process.

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  Highly functional nano metal powders such as Ag, Au, Cu, CuNi and CuAg were developed using a specially designed RF plasma synthesis equipments operating at 20kW and 13.56MHz and their material properties were characterized. In the examination of their morphology by TEM and SEM, the nano metal powders had a perfect round shape with either ball type or hollow type, depending upon their cooling rates. In order to ascertain whether a single nano powder is ball type or hollow sphere, it was drilled out by fs-laser. Very large size hollow spheres were found. They showed the strongly affirmative behaviors to human body by the subsequent evaluation experiments. It was found that the nano metals were not oxidized under the atmospheric environment. These kinds of property changes were directly confirmed by their magnetic properties.

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It has been pointed out for some time that sooner or later resources will be exhausted irrespective of their renewability. When this happens, the present humanosphere could not sustain itself. Cyclic use of resources, while generating no environmental loads and inflicting no social injustice, may be a part of the solution. The utmost economies in using resources as well as stockpiling and right-sizing should be also observed. Once incorporated into the humanosphere, the resources must be utilized thoroughly. Based on these, three principles and six practices for prolonging resource use are given. A peaceful continuation of the humanosphere hinges upon our success in adopting the appropriate way of distributing resources. In order to achieve this, we first need to share core values according to which the order of priority among human needs is determined. Resources are considered as global commons and allotted based on the global limits and on the material and energy requirements/disposal for each need. From this point of view, contentment and moderation appear to be important, and four core values are proposed. Recognizing the difficulty of realizing stable sociogeochemical circulations, humans who succeed in attaining this feast have been compared to an emergence of a new human species, Homo sapiotempus.

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The mechanical, thermal and electronic properties of the nanoscale materials are studied using an ab initio molecular dynamics (TBMD) method and statistical moment method (SMM). We investigate the strength and fracture behaviors of nanoscale materials like carbon nanotubes (CNT), graphens and nanowires in comparison with those of corresponding bulk materials. The thermal expansion coefficients, linear elastic parameters, nonlinear elastic instabilities, yield strength and fracture behaviors are studied including the anharrnonicity of thermal vibrations. We will show that the thermodynamic and strength properties of the nanoscale materials are quite different from those of the corresponding bulk materials. The electronic density of states and electronic transports of the nanoscale materials, with and without the atomistic defects are also discussed.

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  Start functions of a real-space density functional (RDF) approach are proposed using the results of the linear combination of valence bonds (LCVB) method. As the first step basis data of the DF calculations, spatial electron densities in molecules are determined with the LCVB method. For increasing precision of these data, the atomic orbitals are corrected with modification functions by means of the improved Rosen's method, where the precision is fairly increased and the virial coefficient is satisfied.

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We have simulated grain growth process of a Cu ultra fine wire by the phase field method. As the model of the calculation, we used the poly crystal model of Kobayashi-Warren in which the phase field and the orientation field are considered. The section of the fine wire was divided into 2-dimensional meshes and the time developing equations of the phase field and the orientation field were solved numerically. The isothermal annealing was simulated on the condition of the annealing temperature 523-973 K and the annealing time 333 second, and the constant- rate annealing process was simulated on the condition of the first temperature at 373 K and the final temperature 673-773 K with heating rate 0.45-9.01 [K/s]. In order to clarify the effect of heating rate on the crystal structure, the post-isothermal annealing was performed in the simulation to make the thermal energy supplied to the sample equal among the various annealing processes. The change of the crystal grain radius was investigated by varying the heating rate. It was found that the crystal grain radius obtained by a certain range of the heating rate 1.29-9.01 [K/s] is larger than that obtained by the isothermal annealing.

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In the production of LSI, annealing process is necessary to coarsen the crystal grains in the wire. In this process, the wiring breakdown is frequently caused by the defect generation in the bottom of the buried wire. To overcome this difficulty, we investigated the conditions for the defect generation and the atomic behavior during the annealing process by the molecular dynamics simulation. Three rigid plates are placed as the two sidewalls and the bottom of the wire with a rectangular parallelepiped shape. A single crystalline copper is placed as the material of the wiring and the covered layer. After the relaxation at a low temperature for the structural stabilization, an annealing temperature is set for the sample. Calculation parameters are the annealing temperature, the thickness of the covered layer, the width, the height and the strain of the wire. It was shown that defect generations are suppressed when the annealing temperature is lower, the dimension of the wire is larger and the compressive strain is larger. These results coincide with the tendency of the real experiments.

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Atomistic configuration and motion of dislocation have been simulated by means of molecular dynamics method. The embedded atom method potential for copper is adopted in the simulation. Model crystal is a rectangular solid containing about 140,000 atoms. An edge dislocation is introduced along [112] direction near the centre of model crystal, and the system is relaxed. After the dislocation configuration is stabilized, a shear stress is applied and released. Wavy motion of dislocations is developed on the Peierls valleys when the free boundary condition is adopted. Propagation of phonon and dislocation-phonon interaction in the crystal are also simulated.

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Bordoni relaxation (BR) of internal friction peaks in fcc metals around liquid nitrogen temperatures, was investigated experimentally using a pure aluminum crystal by a resonant bar method of 51 kHz. Each time after slight deformations or subsequent anneals, we measured the BR at temperatures between 78 K and 250 K. Usually the Bordoni relaxation consists of two broad peaks, i.e., the Bordoni peak (B₂ peak) at higher temperature (～180 K) and Niblett-Wilks peak or shoulder (B₁ peak) at lower temperature (～120 K). It was not expected that after an anneal at 800 K in air, there appeared four sharp internal friction peaks for the temperature range of BR. The peak located at 120 K seems related with B1 peak. The remaining three peaks seem related with B₂ peak. These sharp peaks are found probably for the first time.

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In the present study the grain boundary sliding behavior was investigated on zinc bi-crystal specimens containing some coincidence boundaries. Zinc bi-crystals whose orientations were controlled with seed crystals were grown from the melt by a modified Bridgman method. The (1211), (1216) and (1012) coincidence boundaries in zinc were selected as typical cases. Bi-crystal test pieces where the grain boundary plane is inclined by 45 degrees to the tensile axis had dimensions of about 5mm × 4mm × 50mm. A tensile load was applied to the specimen at elevated temperatures. For the selected coincidence boundaries, the grain boundary dislocation modeling predicts a characteristic behavior of grain boundary sliding, based on the geometric framework of CSLs and DSC lattices. It is predicted that the grain boundary sliding should accompany grain boundary migration whose amount and direction is uniquely correlated to the grain boundary sliding. This theoretical prediction was proved to be true on the (1211), (1216) and (1012) coincidence boundaries where the amount of the grain boundary migration was about 2, 8, and 7 times larger than that of grain boundary sliding, respectively. The experimental results gave a clear-cut evidence supporting the DSC dislocation mode ling of grain boundary sliding in coincidence boundaries.

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We have presented one of mechanisms of anomalous transport properties of stable Al-based quasicrystals, taking into account experimental date for stable Al-based quasicrystals and those approximant crystals by positron annihilation methods.

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A positron lifetime study was performed on nickel to investigate the detection of hydrogen in nanovoids. The introduction of hydrogen into well-annealed nickel by electrochemical hydrogen charging increased the positron lifetime by inducing the formation of vacancy-type defects. Hydrogen was released from 323 K to 423 K and the defects introduced disappeared at 573 K. The Vickers hardness recovered at 323 K with the escape of interstitial hydrogen atoms. The size and number of hydrogen atoms in voids were estimated through calculations. The positron lifetimes in quenched and neutron-irradiated Ni were shortened after electrochemical hydrogen charging due to the trapping of hydrogen in vacancy clusters. The hydrogen in nanovoids escaped during annealing at 373 K.

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Positron spectroscopy based on an electron linac brings a new aspect of methodology for positron research. The intensity of positron beam from linac will be little tenth magnitude compared with that of the standard radioisotope based positron source. Generation of Slow positron based on a dedicated linac is described. The application to nano-structures is also presented.

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We have introduced effective Lagrangian with spontaneously broken density (the hedgehog-like fluctuation) and the massive internal gauge fields. It is suggested that the temperature dependence of the positron diffusion length in the liquid In and Bi metals is described with the restoration of the spontaneously broken density around the positrons due to increasing of temperature.

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We have performed the measurement of reemitted slow-positron spectroscopy for the clean Ni(111) surface and hydrogen adsorbed Ni(111) surface. It is suggested strongly that the disordered hydrogen-adsorbed structure of the β1state contains many vacancy-like defects. It is reported that increase of the reemitted slow positron yield in the (2×2)-2H superstructure on Ni(111), in comparison with that from clean Ni(111) surface, is much related to increase of the electron work function due to the hydrogen adsorption.

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The structural analysis of crown ether was carried out with positron annihilation lifetime spectroscopy. The lifetime of o-Ps was increased with the number of ether group from 0.91 ns to 1.51 ns. The radius of nanoscale open space of crown ether calculated by using Tao-Eldrup equation showed good agreement with the cavity size of crown ether measured with other analytical method such as XRD etc, and this suggested that the annihilation site of o-Ps was in the cavity of crown ether. In comparison between B18C6 and DB18C6, it was found that the lifetime of o-Ps was changed from ca. 1.1 ns to ca. 1.3 ns with the number of benzene ring and the relative intensity of pick-off annihilation of o-Ps was influenced by the number of benzene ring. The change of the lifetime of o-Ps would be due to the influence of chemical modification on the shape of the crown ether ring, and the difference of the relative intensity between them seems to be caused by the inhibition of positronium generation by benzene in molecule.

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  High proton conductivity is one of the desirable features for electrolyte membrane of fuel cell. In general, this depends not only on spatial structure but also electronic state relating to functional group. Positron annihilation technique seems is a powerful method to analyze such properties, since the size of open space can be measured by lifetime of positron/positronium and the electronic states can be estimated by Doppler broadening of annihilation gamma-rays which is characterized by line shape parameter, S. We have measured the electrolyte membranes composed of hydrocarbon in backbone with sulfonic group in side chain by positron annihilation technique and found that the lifetime and S were influenced by the density of sulfonic group.

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We have developed a positron microbeam using magnetic lenses based on the commercial scanning electron microscope (SEM). A slow positron beam was generated using a handmade ²²Na source and a solid neon moderator. The minimum beam diameter was 3.9 μm on target. Two-dimensional image of S parameter was successfully obtained. By introducing a beam pulsing section, positron lifetime measurement is also available.

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We present results based on first-principles calculations of a computational search for half-metallic (HM) ferromagnetic (FM) and antiferromagnetic (AFM) materials within the class of zinc-blende-structure pnictides and chalcogenides that incorporate 3d-transition-metal ions. Six HM-FM results are found for pnictides (VAs, VSb, CrAs, CrSb, MnAs, and MnSb) and four results for chalcogenides (VSe, VTe, CrSe, and CrTe). Theoretically predicted HM-AFM's with no net magnetization, or fully compensated ferrimagnetic materials, represent a fundamentally different state of matter. A promising possibility is in ternary systems such as chalcopyrites and [001]-oriented monolayer superlattices containing either transition-metal pair: CrFe or VCo. This study provides viable candidates for these unusual magnetic materials that would be realized using atomic-layer-by-layer growth techniques for future spintronic applications.

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Recent studies on spin accumulation and tunnel magnetoresistance (TMR) in nonmagnetic metal nanoparticles are reviewed, and a potential device application for magnetoresistive random access memories (MRAMs) is proposed, based on the unique magnetotransport properties in nonmagnetic nanoparticles.

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  We prepared diluted-magnetic semiconductors (DMSs) Gd doped GaAs on GaAs (001) substrates by means of molecular beam epitaxy (MBE) method and their magnetic and structural properties were investigated. Samples with different Gd concentration were obtained from different growth conditions of vapor flux rates of Gd and Ga. Reflection high-energy electron diffraction (RHEED), cross-sectional transmission electron microscopy (TEM) show that GaAs:Gd DMSs were grown epitaxially on GaAs buffer layer. X-ray diffraction (XRD) profiles indicate that there are two phases, GdAs compounds and GaAs matrix with slightly doped Gd. The lattice constant around a Gd atom seems to be larger than GaAs one. From the result of magnetization measurement, GaAs:Gd DMS shows a ferromagnetic-like behavior at room temperature.

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  High-T_c superconductivity may be possible upon metallic-element doping into boron icosahedral cluster solids. We attempted magnesium (Mg) doping into α-rhombohedral boron (α-B₁₂) and β-rhombohedral boron (β-B₁₀₅), and discussed the possibility of metal transition and superconductivity. Although the preparation of Mg-doped α-B₁₂ cannot be achieved, we achieved Mg doping into β-B₁₀₅ at a high Mg concentration of up to MgB_11.5 (8.6 Mg/cell), which. is the highest metal concentration of β-B₁₀₅ up to now. However, neither metal transition nor superconductivity was observed. We estimated the density of states (DOS) near E_F and discussed the electronic states of β-B₁₀₅. From the result, it is suggested that a localized state exists above the intrinsic acceptor level probably originating from the B₂₈ cluster with structural defects.

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α-gallium is the most stable phase of gallium under the normal condition. The electron density distribution of α-gallium was obtained from X-ray diffraction data. Weak covalent bonds are observed in the (100) layer and interlayer bonds are weaker than intralayer bonds. Interlayer bonds are thought to be metallic bonds. This coexistence of two types of bonds is considered to cause the pseudo gap structure of density of states.

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  We attempted to synthesize solidified AgPb₁₈SbTe₂₀ doped with PbI₂, which is an n-type dopant for PbTe, and evaluated its electrical and thermal conduction properties in order to investigate the possibility of improving its performance. Large amounts of dispersed and interconnected precipitates with a size of approximately 100 μm were observed, and small cobweb-like precipitates were observed in these precipitates. The consistency of Ag, Sb, Te, and I in these areas was found to be higher than that in other areas. It is suggested that the precipitates are AgSbTe₂. The consistency of Ag in the small cobweb-like precipitates was found to be higher than that in other areas. It was evident that the carrier density at room temperature was approximately three times higher than that of undoped AgPb₁₈SbTe₂₀. It was found that the figure-of-merit at room temperature was 2.4 times higher than that of undoped AgPb₁₈SbTe₂₀. The temperature dependence of 1/(resistivity ρ × thermal conductivity κ), which is a factor of the performance of thermoelectric materials, was evaluated. It was found that 1/(ρκ) is larger than that of undoped AgPb₁₈SbTe₂₀ at temperatures below 170°C. It was suggested that doping of PbI₂ contributed to the improved thermoelectric performance.

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In-situ powder-in-tube processed MgB₂ tapes have been prepared through a hot pressing and conventional heat treatment. Magnesium hydride MgH₂ and amorphous B powder mixed with SiC powder addition was encased in a carbon steel tube to form a core/sheath composite. The composite was fabricated into a square rod by grooved-rolling, then into a monocore tape 4mm in width and 0.5mm in thickness by flat rolling. The hot pressing was performed under 100 MPa in the temperature range of 630-800°C for 1-10 h in Ar gas atmosphere. The combination of hot pressing during the heat treatment and the addition of SiC nano-sized powder appreciably enhanced the core Jc for the MgB₂ tapes. The core Jc at 4.2 K for the 5 mass% SiC addition tape hot pressed at 630°C for 10 h was 125 A/mm² at 10 T, 500 A/mm² at 7 T and close to 1,000 A/mm² at 5 T, respectively. Hot pressing prevented voids due to the volume reduction in MgB₂ synthesis reaction, and strengthened the linkage among MgB₂ grains. The addition of SiC nano-sized powder enhanced the core Jc, especially the Jc. at high magnetic field due to the improvement of Hc₂ and refinement of the MgB₂ grains.

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The effects of several surfactants (Pb, Bi, and Ag) on the homoepitaxial growth of Fe(100) have been studied and compared. Our measurements clearly revealed that Pb and Bi were effective surfactants for enhancing layer-by-layer (LBL) growth in the Fe(100) homoepitaxy. Ag had the same effect, but it was less efficient due to the weak surface segregation of Ag. Using a surfactant Bi, we investigated the surfactant effect on the heteroepitaxial growth of Cr on Fe(100). It was found that a suitable amount of Bi enhanced the LBL growth of Cr on the Fe(100) surface. The surfactant effect of Bi on the heteroepitaxial growth of Fe/Cr(100) multilayers on the Fe(100) surface was also investigated. Predeposition of a small amount of Bi (0.08 ML) enhanced the LBL growth of the Fe/Cr(100) multilayer. The interface structures of the Fe/Cr multilayer with Bi were sharper as compared to the multilayer without Bi.

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  The counterion immobilization has been investigated about a brush configuration of a strong polyelectrolyte, sodium polystyrene sulfonate (NaPSS). Zeta potential of the planar NaPSS brushes was measured under a variety of salt, sodium chloride (NaCl), concentration conditions. Analysis based on Poisson-Boltzmann equation provided the amount of counterion that was unimmobilized and hydrodynamically mobile outside the brush layer. Its salt concentration dependence revealed the counterion immobilization to be weakened by the salt addition with following a power law between the unimmobilized counterion rate and the added salt concentration.

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Synthesis of cubic boron nitride in equilibrium condition requires very high severe condition. In this paper, we report the experiment to make cubic boron nitride by nitrogen ion implantation to boron film. The velocity of ion beam accelerated by electrical potential is one hundred times higher than that of explosive power of chemical reaction, such as dynamite, which means the temperature of the implanted ion is as high as 500 million degrees. On the experiment, boron film was prepared on a single-crystal silicon substrate by RF sputtering. It was implanted by N₂⁺ ion with ion accelerating voltage 30kV, at doses of 1.0x10¹⁷ ions/cm², etc. The microstructure identification was carried out by transmission electron microscopy. The t-BN, c-BN and w-BN were confirmed to be synthesized in the film.

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Damage accumulation in bovine cortical bone under cyclic loading was characterized by AE monitoring and ultrasonic wave velocity measurement. Static and fatigue compression tests were performed and microfracture process was investigated by AE technique. In static test, remarkable AE increase was observed only at final fracture, while continuous AE activity was observed during fatigue test. Longitudinal wave velocity along radial axis of the bone decreased gradually during fatigue loading. Furthermore, the AE signals corresponding crack opening and closure were discriminated. Comparing the AE behaviors during static and fatigue tests, and decrease in wave velocity during fatigue test, it was understood that the crack opening AE emitted from crack propagation and crack closure AE has dominant role for degradation of strength of bone under cyclic loading.

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Niobium disilicide (NbSi₂) layers were applied on γ-TiAl specimens to enhance their oxidation resistance at 1050 °C. The NbSi₂ layers were prepared by joining thin Nb foils to γ-TiAl surfaces, and siliconizing the Nb/γ-TiAl using molten salts. The coatings and their oxidation behavior were characterized using X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy techniques. Isothermal oxidation tests showed that oxidation resistance of the uncoated γ-TiAl at 1050 °C in air was inadequate for prolonged exposure and scale spallation occurred, causing severe oxidation of γ-TiAl at high temperature. NbSi₂ coatings were formed and adhered firmly to the underlying γ-TiAl. Oxidation of the NbSi₂-coated γ-TiAI (NbSi₂/Nb/γ-TiAl) at 1050 °C in air showed improved oxidation resistance at exposure time of 10 h. The NbSi₂ coatings provided good intrinsic oxidation resistance at 1050 °C in air for prolonged oxidation exposure, and showed potential use in protecting γ-TiAl at high-temperature applications.

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It was found that nitrogen-doped TiO₂ revealed significant improvement in high photocatalytic reactivity under visible-light [Asahi et al, Science 293, 269-271 (2001)]. To investigate the optimal local concentration of doped nitrogen for visible-light response, N⁺-implanted TiO₂ samples were examined by means of X-ray absorption near edge structure (XANES) and electron energy loss spectroscopy (EELS). Depth-resolved nitrogen K-edge EELS revealed two types of chemical state of nitrogen, depending on the concentration, consistent with the XANES results. We found that the local nitrogen concentration effective for visible-light response was approximately less than 1 at%. Further, we visualized the spatial distributions of the different chemical states of nitrogen by energy-filtering TEM (FETEM). It was also found that the photocatalytic activity was offset by the coexisting inactive state.

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All solid-state ion-selective electrodes (ISEs) based on silver sulphide pressed pellets were fabricated. The electrode was found to be sensitive and selective to Ag⁺ and S^-ions, and followed the Nernstian behavior in the concentration of 1 x 10^-1 to 1 x 10^-5M with slope of 31.5 mV and 57.5 mV per decade change in S^-and Ag⁺ ion concentrations, respectively. The electrode was used to determine the solubility products of Ag₂CrO₄, AgBrO₃, and AgSO₄ and the amount of H₂S in the cigarette smoke. The average amount of H₂S per stick of a cigarette was found in the range of 0.0332 to 0.0766 mg. The iodide, bromide, and chloride selective electrodes were also fabricated by incorporating appropriate amount of Agl, AgBr, and AgCl in silver sulphide. The potentiometric selectivity coefficients of the iodide for bromide (K^pot_ГBr¯) and chloride ions (K^pot_ГCl¯) were found to be 1x10^-2 and 5x10^-3, respectively. The LaF3 single crystal electrode was used to determine the fluoride ion in fluorinated toothpaste and tea samples. The sensitivity and reliability of these home made ISEs were comparable to the commercial electrodes. Therefore, we believe that the thus prepared electrodes will play a pivoted role in teaching of analysis with ion-selective electrode.

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  Erosion behavior of Supercritical Nano-Plating (SNP) material was studied, especially focused on the dependence of the tilting angle between plate surface and blasting direction. Tilting assembly was installed in the commercially available blasting machine which is used for drawing graphical pattern on glass tableware by powder blasting. Damaged surface and cross-section were observed with optical microscope and scanning electron microscope. Normal and tangential force measurement unit was introduced for the measurement during erosion tests. Superiority of SNP was confirmed as thinner controllable plating of higher hardness with excellent integrity against powder-blasting erosion, compared with conventional method. Tangential force during erosion test was not measured successfully but measured normal force showed good agreement with theoretical expectation. It would be suggested that better understanding of the damage process during powder-mixed blasting needs the detailed research on powder impact behavior itself.

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Plasma generated in supercritical fluid (SCF) is anticipated to yield a unique reactive field due to a combination of the high reactivity of plasma and the superior transport properties and density fluctuation of SCF. To effectively use the unique characteristics of SCF, it is important to prevent an increase in gas temperature, which degrades the unique characteristics of SCF. The space and time restrictions of the plasma have been the typical methods for keeping the gas temperature of the plasma generated in a high-pressure environment low. In our previous study, it was found that a reduction in plasma size contributes markedly to the appearance of the novel phenomenon of discharge generated in SCF. In this work, using pulsed DC voltage, we generated time-restricted discharge plasmas in supercritical CO₂ and discuss the effect of the time restriction of the plasma generation by pulse technology on the SCF plasma and SCF plasma processing. Moreover, using nanosecond-order pulsed DC voltage, we successfully fabricated carbon nanomaterials, such as carbon nanotubes (CNTs), from CO₂, without the electrode being seriously damaged by the discharge plasma in a supercritical CO₂ environment.

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  Microgels composed of poly(N-isopropylacrylamide-co-acrylic acid) with different acrylic acid contents were prepared. The dispersion of microgels with higher AAc content exhibited affinity with human immunoglobulin G (IgG). The maximum adsorption was observed around pH 5.0, while both low pH and basic conditions induced the rather low adsorption caused by electrostatic repulsion. Two-dimensional (2D) arrayed microgel was prepared and IgG adsorption on the an-ay was compared with above mentioned adsorption in dispersion of microgels. Adsorptions of IgG on 2D particle array and in the dispersion exhibited similar dependence on both pH and temperature. Surface plasmon resonance (SPR) was used to investigate the kinetic parameters of protein binding onto 2D-arrayed microgels. The association and dissociation rate constants and the corresponding affinity at various pHs were obtained.

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We present the synthesis of organic/inorganic hybrid microgels. To obtain well-structured hybrid microgels, pre-formed polymer microgels were used as “templates” for synthesis and growth of several inorganic nanoparticles in situ. In addition, we present the assemble of colloidal crystals composed of various core/shell structured microgels and their hybrid microgel counterparts which contain localized Au nanoparticles.

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A possibility of full-scale applications of the some hydro gels as environmental purifying materials has been examined by measuring the capturing amount of the heavy metals. The experimental results indicate that the hydrogels can be fully useful for such applications with an advantage in the quantity of the captured ion per the absorbent weight over other adsorbents.

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The accidental explosion of natural gas is almost deflagration from beginning to end. Material failure mechanism with deflagration was studied with the steel vessel of a fragile material on the end. The breakage pressure depends on pressure increasing rate. Rapid pressure increasing causes higher pressure breaking. The tensile tests of different tensile speed showed that the constant strain breakage ruled the material breakage. The rheology model of material breakage with the increasing stress could explain the constant strain breakage mechanism. Voigt model (or Kelvin model) consisted of a spring and a dashpot was suitable for the rheology model. The tensile tests determined the coefficients of the spring and the dashpot of the model. These 2 parameters and the breakage strain (= constant) predict the breakage pressure and time. A case study of tracing paper as the fragile material showed good result of this approach. Further studies of actual constructional material as steel bar, float glass, duralumin plate are needful for next engineering step.

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Diamond was synthesized by microwave plasma CVD and hot filament CVD. (111) textured diamond films were synthesized from CH4-H2 reaction gas system and (100) textured films were synthesized from CO-H2 reaction gas system using microwave plasma CVD, respectively. Boron doped and non-doped CVD diamond films were synthesized using hot filament CVD from CH4-H2 reaction gas system with B4C as a dopant. An electrochemical property was estimated by a cyclic voltammetry. From the SEM observation, polycrystalline diamond films were observed. For samples prepared by microwave plasma CVD method, (111) texture films and (100) textured films were obtained from different reaction gas systems. Also polycrystalline CVD diamond films were observed both boron doped and non-doped samples using hot filament CVD. From the estimation of Raman spectroscopy, peaks of diamond were obtained at 1333 cm-1 in their Raman spectra. As a result of cyclic voltammetry, the potential windows were broad. The areas of the potential window of CVD diamond films were different respectively and they were depended on growth conditions and CVD methods.

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Two types of x-ray diffraction methods for measuring stress state in a single crystal are proposed. The first one is tuned to the laboratory x-ray diffraction system. The diffraction data for several equivalent diffraction indices are obtained by using our original apparatus and the multiple regression analysis method is applied for the solution algorism of the plane stress components. The second one is suitable for investigating the residual stress state in an inner part of a single crystal by using high energy synchrotron radiation facility. The stress components can be directly analyzed by solving the stress-strain equation for a single crystal with the diffraction data in three orthogonal directions. The experimental demonstrations are also shown for the residual stress analysis of laser-irradiated Fe single crystal.

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  α-FeSi₂ alloys were solidified from undercooled melts on electromagnetic levita tor. The in-situ observation of the solidification behavior was conducted using a high-speed video recorder. At ΔT >100 K, the sword-like dendrite with hexagonal symmetry was shown, despite the tetragonal structure of α-FeSi₂. In this study, the formation of six-fold dendrite from undercooled melts was examined from the point of view of the competitive nucleation based on the analysis of crystallographic orientation using an electron backscattering pattern apparatus. We propose that the six-fold symmetry resulted from the three different crystals growing into the <110> direction of the (111) plane of the metastable cubic phase of γ-FeSi₂.

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  Poly(fumarate)s possess rigid main-chain moieties originating from the steric hindrance of densely packed side-chains. Besides such rigid characteristics, one of the most important features of poly(fumarate)s is the capability to vary the number and nature of side-chain functionality especially when mesogenic groups are anchored. Fumarate monomers carrying two mesogenic groups (abb. Bis-F) can be polymerized to afford the polymethylenes with the doubled mesogen density as compared to the ordinary α-olefin polymers, leading to a facile appearance of liquid crystal phase. Polymerization of fumarate monomers carrying an isopropyl and a mesogenic group (abb. Mono-F) similarly provides the corresponding rigid polymethylenes with the same mesogen density as α-olefin polymers. Copolymerization of Bis-F and Mono-F yields the polymethylenes with the intermediate mesogen density. In this paper, the phase transition behaviors of a series of novel poly(fumarate)s with different cyanobiphenyl mesogen density were studied. Although poly(Bis-F) exhibited the smectic phase, copoly(Bis/Mono-F) showed the nematic phase and poly(Mono-F) did not display any liquid crystalline phases. Moreover, the liquid crystalline temperature range was very wide for poly(Bis-F). These results clearly suggest that higher mesogen density is more advantageous for realization of well-ordered liquid crystalline phases, such as smectic phase, in side-chain liquid crystalline polymers.

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We have demonstrated sensing for Bovine Serum Albumin (BSA) by interference color system. Uniform layer of anti-BSA formed on SiO₂/silicone thin-layers, which showed the interference peak in visible light region, was successfully utilized for BSA sensing by reflective spectrum. BSA was detected over 1.0×10^-8 M by interference color system. Development of the antigen sensing system without special reagent for second antibody having fluorescent moiety would lead to construct a novel immunoassay construction.

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Novel nickel(II) dithiocarbamate complexes having amino acid ester moieties, such as valine methyl Ni[S₂CNH{CH(CH₃)CO₂CH₃}]₂ (1), leucine methyl Ni[S₂CNHCH{CH₂CH(CH₃)₂}CO₂CH₃]₂ (2), methionine methyl Ni[S₂CNHCH(CH₂SCH₃)CO₂CH₃]₂ (3) and Ni[S₂CNHC(C₅H₁₀)CO₂CH₃]₂ (4) were synthesized Complex 1 could form a self-organized assembly of micropore structure through intermolecular hydrogen bonding. While complexes 3 and 4 could not form such assembly but they offer chlathrate type assemblies bridged with benzene-1,4-diamine or pyridine-4-ol, respectively.

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The electrochemically-active ligand has synthesized, in which the tetrathiafulvalene module is introduced at the 6-position of 1,4-di(2,2':6',2"-terpyridin-4'-yl)benzene (TTF-bTP). The synthesis was confirmed by MALDI-TOF MS and ¹H NMR. The organic-metal hybrid polymer consisting of TTF-bTP and Fe(II) was prepared. The formation of the hybrid polymer was monitored by UV-Vis spectrum titration and confirmed the polymeric objects by atomic force microscopy (AFM).

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  An ionic liquid crystalline polymer (ILCP) with photoactive azobenzene pendant groups was deposited as a multilayered Langmuir-Blodgett (LB) film. The layer structure and the orientation of the azobenzene pendant groups in the LB film were drastically changed upon irradiation with UV and visible lights. The layer order in the LB film was completely disturbed by UV light irradiation, and rebuild by visible light irradiation. Homeotropic molecular alignment with the consequent double layered structure is consistent with that of a smectic A liquid crystalline phase of ILCP.

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  Langmuir monolayers and multilayered Langmuir-Blodgett (LB) films of main chain liquid crystal polymers (MCLCPs) having 1,4-bisstyrylbenzene (BSB) groups and polyoxyethylene (POE) chains were prepared. The properties of monolayers at an air-water interface can be related to the characteristics of these polymers in the bulk LC phase. The multilayered structure of the LB film is consistent with that of the smectic LC phase. In the layer, the BSB groups form the H-aggregated structure and the POE chains form the hair-pin loops.

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