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A new method to evaluate the critical cooling rate, Rc of Fe-based metallic glass alloy was proposed and discussed. [(Fe0.5Co0.5)0.75B0.2Si0.05]96Nb4 alloy particles were prepared with narrow size distribution and high sphericity by Pulsated Orifice Ejection Method in Ar, He and 50%Ar+50%He mixed atmosphere, respectively. Phase transition of a particle from amorphous to amorphous-crystalline and fully crystalline occurred with the increase of particle diameter. Rc of the formation of fully amorphous phase was estimated to be in the range of 700-1100 K/s, lower than that measured by time-temperature transformation diagram of bulk metallic alloy. No change of Rc occurred in Ar, He or 50%Ar+50%He mixed atmosphere, which proved it an effective method to evaluate the critical cooling rate of Fe-based metallic glass alloy.

Multi-walled carbon nanotube (MWCNT)-reinforced copper (Cu) nanocomposite coatings were successfully deposited on aluminum (Al) substrate by a cold spraying process at a low pressure. The microstructure and the Raman spectrum of the low-pressure-cold-sprayed MWCNT–Cu nanocomposite coating showed that the MWCNTs maintained their tube structure in the Cu matrix, even though structural damage to the MWCNTs increased slightly. MWCNT–Cu nanocomposite-coated Al exhibits higher thermal diffusivity than pure-Cu-coated Al with a comparable hardness. The higher thermal diffusivity of the MWCNT–Cu coating could be explained by the dispersion of MWCNTs within the clean and closed CNT/Cu interfaces, which were achieved with the aid of compressive stress during the cold spraying.

A simulation method was used to study the effects of physical parameters, including the contact angle between molten metal and material of orifice, surface tension and viscosity on particle formation of POEM. Droplets can be stably obtained only when the contact angel is at least 90° or larger, as well as the surface tension is adequate. Within a wide range, viscosity has little effect on droplet formation; as the viscosity increases, necking time is postponed and vibration time is shortened.

The interface in multi-walled carbon nanotube (MWCNT)–metal matrix composites significantly effects the interfacial thermal diffusion characteristics vary due to the presence of an interphase. The thermal conductivities of MWCNT–copper (Cu) composites with and without amorphous impurity layers at the MWCNT–Cu interface as well as the Cu grain boundary have been studied. The measured thermal conductivities of composites containing chemically treated MWCNT with no amorphous impurity layers were much better than those containing pristine MWCNT. Interfacial and intergranular matrix amorphous layers, thought to originate from Cu oxide in Cu powders and amorphous carbon on the surface of the pristine MWCNT, were observed in the pristine MWCNT–Cu composite matrix. Interfacial amorphous layers a few nanometers thick generated at pristine MWCNT–Cu interfaces act as a thermal barrier and due to the relatively large thermal resistance of these layers the MWCNT are expected to act like elongated pores. Intergranular amorphous layers at the Cu grain boundaries also show thermal resistance, resulting in a decrease in the effective thermal conductivity of the Cu matrix. It is expected that amorphous carbon is partially removed by extended chemical treatment with sulfuric acid (H2SO4) and nitric acid (HNO3), inhibiting amorphous layer formation and resulting in an increase in thermal conductivity of the composites. Our results suggest that extended chemical treatment with H2SO4 and HNO3 is necessary not only for uniform dispersion of MWCNT in the ethanol solution, but also for preparation of clean surfaces free of amorphous carbon in the initial MWCNT for effective MWCNT–Cu composite fabrication.

A hybrid structure of graphene nanoleaves attached on a carbon nanotube and rectangular graphene nanosheets (GNSs) were fabricated by means of radial followed by longitudinal unzipping of crystalline multiwalled carbon nanotubes (MWCNTs) grown by catalytic chemical vapor deposition, using a chemical method containing sulfuric acid and nitric acid. Consecutive unzipping in the radial direction and then in the longitudinal direction of a nanotube has never been reported. Our simple chemical approach will open the path to fabrication for rectangular GNSs in the hundred nanometers by few hundred nanometers scale and a broad application of MWCNTs to the novel carbon nanostructure.

International audience; We have successfully fabricated highly densified aluminum (Al)-diamond composite materials by a simple hot press method. The thermal conductivity of the Al-diamond composite materials was measured. These materials had different types, sizes and fractions of diamond. These obtained values were discussed based on theoretically calculated values. The thermal conductivity of the composite materials, measured by Laser-Flash method, was found to have slightly increased compared to that of pure bulk Al. The obtained microstructures of the composite materials showed a lot of cleavage existing in the interface between the Al matrix and the diamond particles, which led to the low increment of the thermal conductivity. Moreover, Al-diamond bulk materials with different sintering temperatures in solid state, liquid phase, and transient region between solid and liquid of Al, have been synthesized.

The relationships between elastic properties and structures in three-dimensionally periodic porous materials, comprising a periodic array of truncated spheres of air with interconnection pathways embedded in a solid matrix, were investigated both numerically and experimentally. Finite elemental analysis was conducted for the face-centered-cubic (fcc) structure of the air-sphere model, as well as the solid-rod-connected model for comparison. The advantage of the air-sphere periodic structure, having greater rigidity than the solid-rod-connected structure for the same volume fraction, has been emphasized. The calculation results indicated that Young's modulus was consistently larger for the air-sphere model regardless of the size of the interconnection pathways of neighboring air spheres. Additionally, the interconnections were beneficial in lowering the internal stresses. However, it was necessary to focus on the interconnection size to avoid the excessive stress concentration compared with the stress in the solid-rod-connected structure. Polymer-inverted porous structures of fcc particle arrays with a solid volume fraction of 26.0% were fabricated by the combination of sintering self-assembled, monosized copper particles and replication. Their measured Young's moduli agreed well with the numerical results, confirming the advantage of greater rigidity.

Thermal cycle resistance of Ni-20Cr, Ni-50Cr and CoNiCrAlY coatings produced by air plasma spraying was investigated according to Japanese Industrial Standard Testing method for thermal cycle resistance of oxidation resistant metallic coatings (JIS H 8452: 2008). The specimens were exposed to a cyclic heating and cooling regimen comprised of up to 100 cycles of 10 hours heating to 1000 °C or 1093 °C in air followed by cooling. The thermal cycle resistance of oxidation-resistant metallic coatings was found to depend strongly on testing temperature and on the chemical composition of the coating materials. In thermal cycle testing at 1000 °C, no remarkable failure was observed in any specimen. However, in thermal cycle testing at 1093 °C, spalling was observed over the entire surface of the Ni-20Cr coating, although the Ni-50Cr and the CoNiCrAlY coatings exhibited excellent thermal cycle resistance even upon exposure to 100 thermal cycles. The CoNiCrAlY coating showed mass gain with increasing number of thermal cycles due to preferential oxidation between thermal spray particle splats. Furthermore, the failure behavior of specimens was investigated in detail by SEM, XRD, EPMA, etc.

The effect of microstructure upon thermal expansion and sintering shrinkage in plasma-sprayed zirconia coatings was investigated by an accurate dilatometry. Cut-out samples with different microstructures were prepared from 5.8-mm-thick atmospheric plasma-sprayed (APS) and water-stabilized plasma coatings (WSP). It was quantitatively determined that the samples cut out of different thickness positions had minor differences in microstructure, and these APS samples largely differed from the WSP samples. The thermal expansion behaviors of all the samples coincided after a short annealing time despite their initial structural differences. On the other hand, all the samples showed a significant difference in sintering shrinkages with annealing at 1400 °C. This result was consistent with the theoretical result calculated with Cipitria's sintering model in terms of the relationship between shrinkage and microstructure. It was therefore demonstrated that the initial microstructure, particularly the splat thickness and the inter-splat pore height, exerts a great influence on the sinterability of plasma-sprayed coatings.

Spark plasma sintering and hot extrusion processes have been employed for fabricating carbon nanofiber (CNF)-aluminum (Al) matrix bulk materials. The Al powder and the CNFs were mixed in a mixing medium of natural rubber. The CNFs were well dispersed onto the Al particles. After removal of the natural rubber, the Al-CNF mixture powders were highly densified. From the microstructural viewpoint, the composite materials were observed by optical, field-emission scanning electron, and high-resolution transmission electron microscopies. The CNFs were found to be located on every grain boundary and aligned with the extrusion direction of the Al-CNF bulk materials. Some Al carbides (Al4C3) were also observed at the surface of the CNFs. This carbide was created by a reaction between the Al and the disordered CNF. The CNFs and the formation of Al4C3 play an important role in the enhancement of the mechanical properties of the Al-CNF bulk material. The CNFs can also be used for engineering reinforcement of other matrix materials such as ceramics, polymers and more complex matrices.

In this study, we prepared monodisperse spherical particles of a desired diameter using [(Fe0.5Co0.5)0.75B0.2Si0.05]96Nb4 alloy; the particles were prepared by using an atomization process developed by us. The particles have perfect sphericity and narrow size distribution along with a homogeneous composition. The phase transitions of particles from the fully glassy phase to the crystalline phase via mixed phase structures occurred as the particle diameter was increased; the particles produced in the fully glassy phase in an argon atmosphere had a diameter of less than 300 μm. This allowed the estimation of the intrinsic critical cooling rate for the particles with a fully glassy phase, Rc:Rc varied in the range of 700–900 K/s and depended only on the initial temperature of the alloy melt.

Graphene nanoribbons (GNR) have been fabricated by a microexplosion method without severe oxidation – filling multi-walled carbon nanotubes (MWCNT) with potassium and then reacting with water vigorously. Transmission electron microscopy and scanning transmission electron microscopy have verified the synthesis mechanism: when MWCNTs are effectively filled with potassium, the microexplosion generated by reaction between water and potassium can split the MWCNTs to form GNRs. Most of the obtained GNRs have smooth edges and the maximum wall thickness of MWCNTs that can be split by this method is around 10 nm.

It is well known that growth of Suaeda salsa (L.) Pall. is stimulated by NaCl application. However, the physiological role of sodium in the growth of Suaeda salsa has not been elucidated. We thus examined the physiological role of sodium in the growth of Suaeda salsa grown in nutrient solutions containing 5 mmol L ―1 Cl ― and graded concentrations of Na 2 SO 4 . Sodium concentrations in plant tissues increased as the growth medium salinity increased. The osmolality gradient between plant tissues and growth medium was maintained at constant levels despite the increase of osmolality in the growth medium. As a result, the amount of water absorbed by the plant tissues was not significantly affected by the salinity of the medium. The dry weight of the S. salsa plants did not increase significantly as sodium concentrations in plant tissues rose. As salinity of the medium increased, the contribution of water-soluble sodium to the osmolality in the leaves, stems, and roots also rose. There was a significant positive correlation between sodium concentration and osmolality in plant tissues. These results suggest that sodium is the major cation contributing to the maintenance of high osmolality in plant tissues of S. salsa grown under the high-salinity conditions. Therefore, under high-salinity conditions, the physiological role of sodium may be to maintain water absorption by maintaining osmolality in the plant tissues, which would help explain the normal growth of S. salsa under high NaCl conditions.

The thermal conductivities of carbon nanotube (CNT)–copper (Cu) composites are greatly increased for compositions containing up to 1 vol.% CNT and remain above the value for pure Cu up to 3 vol.% CNT. The obtained enhancement was in good agreement with estimates based on Eshelby’s equivalent inclusion method. This agreement suggests that very low thermal resistance might be realized at the interface between CNTs and the Cu matrix, which consists of faceted and closely attached interface without any compounds.

β-Tricalcium phosphate (β-TCP) scaffolds with an ordered pore structure were fabricated by ceramic slip casting using a particle-assembled template. An ordered pore structure is expected to enable uniform and accurate improvement in the topology of the porous structure of scaffolds. Monosized spherical polyethylene particles were self-assembled into an fcc lattice by close-packing with a pyramidal indentation and heat-treated for interparticle necking. β-TCP slurry was cast with this particle array, followed by heat treatments to burn out the particles and sinter the β-TCP frame. The sintered scaffold showed not only an ordered arrangement of uniform pores but also pore interconnection pathways, which faithfully replicated the particle-assembled structure. High porosity, high pore interconnectivity, and structural controllability, as well as high accessibility, were achieved by this process.

The synthesis and formation mechanism of barium hexaaluminate compound (Ba-β-Al 2 O 3 ) by solid-state reactions between powdered reactants of alumina (Al 2 O 3 ) and barium carbonate (BaCO 3 ) have been investigated. The processes for synthesizing Ba-β-Al 2 O 3 phase include mechanically activated milling of Al 2 O 3 –BaCO 3 powder mixtures and subsequent solid-state reactions at high temperatures. The mechanically activated milling results in a significant decrease in the decomposition temperature of BaCO 3 , hence promotes its reactions with Al 2 O 3 . Almost monophasic Ba-β-Al 2 O 3 can be synthesized by 9–12 h ball milling, followed by heat treatment at 1500 °C for 2 h. The formation of Ba-β-Al 2 O 3 phase includes three stages: (i) decomposition of BaCO 3 , (ii) formation and growth of spherical BaO·Al 2 O 3 particles, and (iii) reaction between Al 2 O 3 and BaO·Al 2 O 3 to form Ba-β-Al 2 O 3 with an elongated morphology.

To consolidate [(Fe 0.5 C 0.5 ) 0.75 Si 0.05 B 0.2 ] 96 Nb 4 metallic glass powder to full density, a pressurized liquid phase sintering was employed, which was intended to promote densification by an enhanced wetting of a liquid phase with solid particles. Pd 42.5 Ni 7.5 P 20 Cu 30 metallic glass powder, which has been reported to have a high glass forming ability and the lowest critical cooling rate of glass formation of 0.067 K/s, was chosen as a liquid phase component. The melting point of the Pd 42.5 Ni 7.5 P 20 Cu 30 metallic glass alloy of 763 K is lower than the glass transition temperature of the [(Fe 0.5 Co 0.5 ) 0.75 Si 0.05 B 0.2 ] 96 Nb 4 metallic glass alloy of 808 K. However, the wettability of this alloy with the Pd 42.5 Ni 7.5 P 20 Cu 30 alloy was revealed to be poor. Therefore, sintering pressure was applied to the compacts to promote a viscous flow deformation of solid particles and also to enhance the intergranular permeation of the liquid phase. A specially designed micro-hot press was devised for the pressure-sintering experiment. A pseudo-wettability was observed during pressure-sintering, and the liquid phase was found to fill completely the intergranular space of the powder compact. The relative density of 64-95%, as well as the sintering structure, could be controlled by the punch displacement to squeeze out a part of the liquid phase from the compact. The compressive fracture strength of the obtained metallic glass composite was found to be as high as 2051 MPa, and the fracture was observed to be intragranular type, suggesting a good bonding in the particle-binding phase interface.

Young's modulus of thermal barrier coating (TBC) is one of the most essential mechanical properties on the designing of high performance TBC system. This paper describes one of the round-robin test results of New Energy and Industrial Technology Development Organization's (NEDO's) project titled “the survey-research of standardization on testing methods for thermo-mechanical performance of ceramic thermal barrier coatings”, for the fiscal years of 2006 and 2007. The bending method of the coating bonded to substrate is straightforward in preparing the specimen and loading to the specimen. Previous study has offered recommended testing methods and proper geometries of the specimens for the Young's modulus of thermal barrier coating and the bond coating. This paper confirmed that the recommended method and the geometry of the specimen provided the reasonable estimation as far as the other type of substrate material. It was also confirmed that the ratio of coating thickness to substrate thickness should be high and the threshold ratio was independent of the substrate material.

The combined processes of spark plasma sintering and hot extrusion were used to fabricate a multi-walled carbon nanotube (MWCNT) reinforced aluminum (Al) matrix composite. The structural defects of carbon nanotubes (CNT) at various sintering temperatures were investigated by Raman spectroscopy. A small amount of Al liquid phase was generated and it reacted with disordered CNTs, even during the solid-state spark plasma sintering process. The influence of Al carbides generated by the reaction between Al and disordered CNTs is discussed from a microstructural viewpoint and in relation to tensile strength. We conclude that structurally controlled CNTs could potentially be attractive for metal matrix applications, and could significantly improve the mechanical properties of AI-CNT composites.

To fabricate artificial crystals with any structure from monosized spherical particles, we have so far manufactured a three-dimensionally particle assembling system with a combination of pick-and-place robotic manipulation and inter-particle laser welding. In the present study, we aimed to assemble large-scale artificial crystals of polyethylene (PE) particles by mean of the new system. In this method, an optimization of the laser welding conditions was indispensable for the strong bonding with maintaining the shape of particles. Thus, the two-particle welding tests were preliminarily conducted. On the basis of this result, we successfully assembled the large-scale artificial crystals with diamond structure from the PE -ceramic or -carbon composite particles. In order to discuss applicability of the obtained crystals to terahertz (THz) wave photonic crystals, the transmittance spectrum of the crystals was evaluated by a THz wave time domain spectroscopy. The PE-ceramic particle crystal presented an ideal photonic band gap which perfectly agreed with the theoretical one.

Ceramics-based thermal barrier coatings are used as heat and wear shields of blades of gas turbine. There are strong needs to evaluate thermophysical properties of coatings, such as thermal conductivity, thermal diffusivity and heat capacity of them. Since coatings are attached on substrates, it is not easy to measure these properties separately. In order to evaluate the thermal diffusivity of coating attached on substrate, we have tried to apply the multi-layer model based on the response function method and established a procedure for the measurement by the laser flash method. We verified the procedure by the measurements from room temperature to about 1000 K for two-layer ceramics sample prepared by the doctor blade tape casting method. The thermally sprayed CoNiCrAlY coating on the SUS304 substrate was also used for verification. The thermal diffusivity of coating attached on substrate approximately agreed with that of the single-layer coating removed from substrate. In the case of the ceramics sample, the thermal diffusivity of the coating including the interfacial thermal resistance determined within about 20 % uncertainty. We compared the laser flash measurement signals of the samples prepared by the thermal spraying with variant thickness and found the difference among them. It was found that the procedure has enough resolution to detect the heat shield effect caused by the change with about 200 m in thickness. The result shows that the procedure and analysis were practically effective for the thermal diffusivity estimation of coating attached on the substrate without remove from substrate.

For FGM thermal barrier coatings thermal-mechanical fatigue due to temperature cycling is one of the critical parameters which determine the lifetime of the TBC. In Tohoku University, a method known as “hot burner test” has been developed and was implemented into the standard JIS H 7851. For further optimization of the testing conditions and selection of the parameters for comparison of different test results knowledge of temperature and heat flux inside the test jig is necessary. FEM analysis of the heat flux and temperature inside the 14 mm diameter test stainless steel jig has been performed. Homogenous YSZ top coat with NiCrAlY bondcoat as well as FGM TBC with different gradation profiles were compared. Distributions of the temperature and heat flux are critical at the edges of the test piece and thermocouples locations, which must be taken into account when comparing test data for coatings with rather different composition and structure. The largest stress gradients develop at the ceramic-metal interface (duplex) and near the edges of the TBC.

We are investigating the feasibility of measuring thermal expansion coefficient (CTE) of free-standing thermal barrier coatings with a practical thickness of several hundred micrometers by mean of a widespread thermomechanical analysis toward its industrial standardization. First of all, this study conducted the preliminary investigation for the accurate measurement of thin samples with dense yettria-stabilized zirconia (YSZ) ceramics. With a sample supporting jig and proper conditions, even the usual thermomechanical analysis could give the accurate CTE values of thin samples down to 0.3mm thick. Also it showed good reproducibility with small measurement error less than 5%. In actual, this modified method could provide the reasonable CTE values of plasma-sprayed YSZ samples with thickness of >0.3mm. Further investigation with this method found a slight monotonic decrease in the CTE with annealing. This decrease was estimated to arise from the continuous change of microstructure which still went on even after saturation of sintering shrinkage. All the results demonstrated the present method to be available for the industrial standard.

Capability of multiwalled carbon nanotubes (CNTs) to create in-depth gradients in properties and functionalities of conventional materials has been investigated for the first time. Functionally graded material (FGM) concept has also been employed for the first time to bridge conventional materials to their advanced nanocomposites containing a high concentration of CNTs, which is promising for unexplored yet novel structural, electronic and biomaterial applications. In this study, α-alumina ceramics considered as the most challenging case has been used as the matrix. Bulk, layered, nanostructure-controlled, CNT-based, functionally graded α-alumina ceramics have been fabricated employing a recently established powder processing technology. In-depth gradients in microstructure, grain size and hardness have been successfully achieved in alumina ceramic without cracking, delamination or warping, after homogeneous and gradual incorporation of the CNTs within the alumina ceramic matrix. The FGM approach showed promise to successfully bridge conventional ceramics to their nanocomposites containing a high concentration of CNTs.

Physiological properties involved in divergent cadmium (Cd) accumulation among rice genotypes were characterized using the indica cultivar ‘Habataki’ (high Cd in grains) and the japonica cultivar ‘Sasanishiki’ (low Cd in grains). Time-dependence and concentration-dependence of symplastic Cd absorption in roots were revealed not to be responsible for the different Cd accumulation between the two cultivars because root Cd uptake was not greater in the Cd-accumulating cultivar ‘Habataki’ compared with ‘Sasanishiki’. On the other hand, rapid and greater root-to-shoot Cd translocation was observed in ‘Habataki’, which could be mediated by higher abilities in xylem loading of Cd and transpiration rate as a driving force. To verify whether different abilities in xylem-mediated shoot-to-root translocation generally account for the genotypic variation in shoot Cd accumulation in rice, the world rice core collection, consisting of 69 accessions which covers the genetic diversity of almost 32 000 accessions of cultivated rice, was used. The results showed strong correlation between Cd levels in xylem sap and shoots and grains among the 69 rice accessions. Overall, the results presented in this study revealed that the root-to-shoot Cd translocation via the xylem is the major and common physiological process determining the Cd accumulation level in shoots and grains of rice plants.

Radioisotope techniques are well known as methods for evaluating symplastic ion absorption in roots. In the present study, a new method for evaluating symplastic cadmium (Cd) absorption in plant roots was developed using the enriched isotopes 113Cd and 114Cd. Seedlings of Solanum melongena were exposed to an enriched isotope solution of 113Cd at 25°C for 30 min. The roots were excised from each seedling and were then immersed in a cold buffer solution without Cd at 2°C for 120 min to suppress the metabolic activity of the roots. Finally, the roots were treated with a cold buffer solution containing enriched stable isotope 114Cd at 2°C for 120 min, whereby the apoplastically bound 113Cd was desorbed. We tested the validity of our method for evaluating symplastic Cd in roots compared with the conventional method based on differences in the amount of Cd absorbed at 2°C and 25°C using unlabeled Cd. There was no difference in the symplastic Cd content of the roots between the two methods. These result...

Aluminum (Al)/carbon nanotube (CNT) composites with nanoscale dispersion and regular orientation of the CNTs were fabricated by a combination of some advanced powder processes. The CNTs were well dispersed onto the Al particles by a nanoscale dispersion method. Moreover, the highly densified CNT composites were prepared by spark plasma sintering and subsequent hot extrusion. Microstructural observations by optical, field-emission scanning electron, and high-resolution transmission electron microscopies confirmed that the sintered Al/CNT compact and extruded bulk material had a good dispersion of oriented CNTs. Raman spectroscopy showed that the processing did little damage to the CNTs. As a result, the composites exhibited tensile strengths that were thrice larger than pure aluminum because of the CNT reinforcement.

Mono-sized [(Fe0.5Co0.5)0.75B0.2Si0.05]96Nb4 alloy particles with desired particle size and high sphericity have been prepared by Pulsated Orifice Ejection Method (POEM). Each particle has uniform compositional distribution along with the same composition during processing. Phase transition of a particle from fully amorphous to amorphous/crystalline and then fully crystalline shows that the diameter of a single fully amorphous particle is less than 300 μm in Ar atmosphere and 700 μm in He atmosphere. The critical diameter of a fully amorphous phase particle shifts toward larger diameter with an increase in the initial melt temperature. The critical cooling rate to realize fully amorphous phase is estimated to be in the range of (700-900 K×s-1), which only depends on the initial melt temperature, irrespective of the atmospheres gases.

Metallic glasses have been reported to exhibit excellent properties, such as high strength, high corrosion resistance, high wear resistance, which result from their amorphous structure. Because of a drastic reduction in their viscosities in supercooled liquid region, metallic glasses have an excellent workability through viscous deformation for the production of various industrial parts. Recently, much attention has been paid to Fe-based metallic glasses because of their rich resources in addition to their excellent mechanical and magnetic properties. However, due to their poor glass-forming ability, the size of the Fe-based bulk metallic glass by conventional casting techniques is limited. In the present investigation, nearly fully densified disk-shaped compacts of [(Fe0:5Co0:5)0:75Si0:05B0:2]96Nb4 metallic glass were produced from a gas-atomized amorphous powder by spark plasma sintering (SPS). The processing temperature and the time that assure the supercooled liquid state of the compacts were determined from the Time-Temperature-Transformation (TTT) diagram that was constructed by isothermal differential scanning calorimetry. The mechanical properties of the consolidated samples were evaluated by compression test. Comparatively low values of the fracture stress, Young’s modulus and yielding stress of SPSed sample compared to the casted samples were observed, which is discussed on the basis of the integrity of the interparticle bonding. [doi:10.2320/matertrans.M2009093]

Japan's military budget has held steady at below one percent of its GDP. Japan spends heavily on personnel for its Self-Defense Forces, support of U.S. bases in Japan, and development of its ballistic missile defense and space development. Yet in recent times, the Japanese business community has also demanded an amendment to Article 9 of the constitution for the promotion of military-civil integrated space development and an end to the ban on arms exports. With the future of Japan's security policy still uncertain after the election of the new Hatoyama administration, innovative disarmament cooperation would better serve the stability of the region than Japan's development of high-tech, offensive military capabilities. Key words: East Asian security, Japan, military spending Introduction In September 2009, a historic political change occurred in Japan, leading to the formation of a coalition government led by the Democratic Party of Japan (DPJ) with Hatoyama Yukio as prime minister. In the previous month's general election, the Liberal Democratic Party (LDP), which had ruled Japan consistently since 1955, went down to an overwhelming defeat and was ousted from government. This was the first time in post- World War II Japanese history that a vote by the people brought about a change in government.1 Resistant to change and with a strong desire to avoid confrontation, the LDP and the governmental bureaucracy had gradually become fused in their management of the nation. While many citizens may have had complaints or been dissatisfied with the status quo, this unified ruling structure also seems to have provided a sense of security. So why did the Japanese public reject the LDP in 2009? The serious economic crisis, the resulting social unease, and the failure of the bureaucratic institutions to deal with these crises all played a part in the political upheaval. From 2001 on, the Koizumi Junichiro administration spent nearly six years pushing neoliberal reform in response to globalization under the name of "structural reform." While earlier administrations made certain moves in this direction, the Koizumi reforms clearly signalled the end of the "Japanese model" whereby the state and corporations jointly provided lifetime security for citizens. With the collapse of this system, one in three workers-or, in the case of young or female workers, more than half-became irregular employees. At the same time, the media repeatedly reported on cases of bureaucrats wasting money or spending state funds for private purposes. The DPJ's success in winning the hearts and minds of the Japanese public stemmed at least in part from its declaration of a "de-bureaucratized rule." To verify and reduce unnecessary spending within the administration, the new government established the Government Revitalization Unit under the cabinet. In drafting the 2010 budget, which totalled more than 95 trillion yen ($950 billion), the DPJ government has aimed to cut as much as 3 trillion yen ($30 billion) as part of its public reconsideration of each and every government program. It has specifically targeted inefficient public works projects and governmental corporations in collusive relationships with the bureaucracy. As they suffer through the economic crisis, people are watching with great interest the television programs featuring sensationalist denouncements of wasteful bureaucratic expenditure. But so far, despite all of these efforts to cut spending, the government continues to treat one sector as "untouchable." Japan's military expenditures remain beyond criticism and serious revision. Japan's Military Budget In 2009, Japan's military budget was 4.774 trillion yen.2 This represents 0.94 percent of Japan's GDP and 9.2 percent of the central government budget. According to the Stockholm International Peace Research Institute (SIPRI), Japan's military spending in 2008 was $46.3 billion, making it the seventh-largest military spender after the United States, China, France, the United Kingdom, Russia, and Germany. …

Isotope dilution techniques were examined in order to determine the E-value (isotopically exchangeable pool or labile pool) of cadmium (Cd) in uncontaminated soil. In order to avoid spectral interference, coprecipitation separation was applied before taking inductively coupled plasma mass spectrometry (ICP-MS) measurements. An enriched 113Cd solution was added to a soil suspension (15 g of soil and 150 mL of water) and then a 2 mL aliquot of it was sampled and filtered immediately at different exchange times. By addition of a sodium hydroxide solution to the filtered solution, Cd coprecipitated with major constituents in the filtered solution, such as iron and magnesium. After the supernatant was discarded, the precipitate was dissolved by adding 1.5 mL of 0.2 mol/L nitric acid. After this treatment, the 113Cd/114Cd ratio in the soil solution could be measured with high precision, within RSD 5%. The correction of mass bias was not required. The proportion of E-values to total Cd concentration in the soil ...

Surfactantless, hydrophilic, slightly disordered, crystalline, multiwalled carbon nanotubes (CNTs) were successfully prepared and then homogeneously and individually incorporated in an α-alumina ceramic by a recently established powder technology to investigate their load-carrying and reinforcing capabilities. As predicted, considerable structural reinforcement was obtained after spark plasma sintering, and microstructural characterizations can experimentally prove the effectiveness of the ability of these CNTs to reinforce the alumina ceramic matrix. Reinforcement mechanisms are thoroughly discussed in terms of microstructural characterizations.

Pulsed spallation neutron sources for the materials structure science are severely influenced by beam impact and radiation damage. We have developed the materials strong to these influence since 2004. In this paper, recent topics are described concerning the development of intergranular corrosion (IGC)-resistant austenitic stainless steel for target vessel and window, radiation-resistant ultra-fine grained tungsten materials (W–TiC) for a solid target, CrN film on a tungsten target by means of a molten-salt method, surface treatment of stainless steel for pitting damage in mercury target. Bubble behavior at the interface of mercury and window glass was also observed to clarify the phenomenon of the pitting damage.

In order to clarify containerless solidification mechanism of falling semiconductor microdroplets, the monosized droplets of germanium in the size range from 200 to 500 μm were ejected by pulsated orifice ejection apparatus method. The density of grains in the resultant particles was dramatically reduced by decreasing the ejection temperature, i.e. initial temperature. A surface observation and orientation imaging microscopy analysis proposed that such microstructural transition was derived from the dependency of preferred growth direction on the undercooling level: the initial temperature determined the solidification undercooling. Numerical calculation with the classical nucleation theory was performed to discuss this phenomenon, but could not sufficiently elucidate the effect of initial temperature obtained experimentally.

Heteroaggregation is employed in a controlled way to the mass-production of individually alumina-decorated multi-walled carbon nanotubes (CNTs) with optimized and controlled compositions, with the aim of obtaining reinforced homogeneously dispersed CNT–alumina matrix nanocomposite after spark plasma sintering. The homogeneous composites can only be obtained for CNT concentrations in the range 2.4–16 vol.%. Irreversibility of decoration is examined, and homogeneity of the composite is further investigated, based on supernatant transparency proposed in our approach.

In the present paper, six V-active brazes were designed. The wetting behavior of Ni–V, Co–V and Ni–Cr–V alloys on Si3N4 was studied by the sessile drop method. The results show that, under the heating condition of 1553 K/120 min, the Ni–V alloys with the V content of no higher than 25 wt.% did not wet Si3N4, whereas, the Ni–V alloys with the V content of no lower than 34.5 wt.% exhibit good wettability. Though the spreading of the Ni–V, Co–V and Ni–Cr–V brazing alloys on the Si3N4 was slow, intensive interfacial reactions occurred, and according to the results of XRD analysis, compounds of V3Ni2Si, V6Si5 and VN were formed at the interface of Si3N4/Ni–V alloy. The corresponding interfacial reactions were also discussed.

湖沼などの閉鎖性水域では富栄養化に伴う水質汚濁や悪臭などが問題となっており，その対策として，排水中の窒素・リンの規制や下水道の整備が推進されているが，あわせて水域内の浄化対策がさらに必要である．本文では，ジオテキスタイルと天然ゼオライトを用いた人工なぎさを提案する．人工なぎさは，天然ゼオライトとそこで生成される生物膜の浄化効果を期待して，天然ゼオライトもしくは玉砂利を充填したジオテキスタイル製大型土嚢と透水シートにより湖岸に囲繞堤を築造し，堤内に天然ゼオライトを敷設するものである．諏訪湖湖岸において実施した実証実験について論じ，現地調査および水質調査の結果に基づいて，提案法の有効性を示した．

Carbon nanotubes (CNT) have many interesting properties such as high thermal conductivity. Therefore, Cu/CNT composites are expected to be applied as heat sink material with good thermal properties.In this study, Cu/CNT precursor in which CNT distributed homogeneously was fabricated by colloidal process, and homogeneous distribution of CNT in Cu matrix was also observed in Cu/CNT composites sintered by spark plasma sintering (SPS). According to the analysis of gas generated from high-temperature precursor, structural defect of CNT, and oxygen content, SPS proved useful to reduce CNT's structural defects compare to conventional sintering methods. Using SPS in vacuum atmosphere, composites can be successfully formed with low temperature in short time. Existence of amorphous layer at Cu/CNT and Cu/Cu interface was observed by FETEM.

The equations for the densification control by viscous flow in the hot pressing of metallic glass powders are derived and a criterion for the full densification thereof and an approach for the porosity control are proposed. The kinetic equations are derived on the basis of Arzt's hot pressing theory; in which the densification is modeled by the contraction of the Bolonoi cell of the random dense packing of spherical particles. The constitutive equation for the viscous flow is obtained from the hitherto proposed creep rate equation setting the rate exponent to be unity. The hypothetical constraint for the deformation due to the three grain edges formed in the later stage of densification is taken into account as a modification of the pressure term in the kinetic equations. The relative density is expressed as functions of hot pressing time and the ratio of the viscosity and the pressure. It is shown that the time required for full densification of metallic glass powders depends only on the viscosity/pressure ratio. The criterion for the full densification is expressed as a straight line on the time-viscosity/pressure ratio plane, which divides the area into full-dense and porous areas. The porosity control of the metallic glass powder compacts is also demonstrated as another practical application of the present theory. The results are discussed on the basis of the reported data.

The formability and sintering behavior of Ni60Nb15Ti20Zr5 metallic glass powder prepared by gas atomizing was investigated using precise hot press equipment. The structure of atomized metallic glass powder depended on its particle size, and only glassy phase was observed when the particle size was under 53μm. The glass transition temperature (Tg), crystallization temperature (Tx), and supercooled liquid region (ΔTx=Tx-Tg) of the Ni-based metallic glass powder was 838 K, 888 K and 50 K, respectively.The hot press sintering under the precise control of temperature and pressure was conducted. The densification behavior depended on only working temperature, and the Ni-based metallic glass powders were consolidated to nearly full density by hot press sintering with working temperature range 863-883 K. On the other hand, the crystallization behavior depended on working time as well as working temperature. In the experimental study this time, the hot press condition achieving both full densification and no crystallization was temperature of 868 K and pressure of 200 MPa. The sintered body of full densification and no crystallization exhibited high corrosion resistance nearly equal to Alloy C-276.

Metallic glasses are potentially applied for accurate micro parts because of their good formability and transferability as well as high mechanical properties and excellent magnetic properties. So the raw materials that the volume is precisely controlled are needed for a highly accurate processing. In this study, mono-sized spherical particles of Fe-Co-based metallic glass were prepared by Pulsated Orifice Ejection Method (POEM) and the capabilities of their micro-forming process in the glass transition temperature were investigated. Mono-sized spherical particles of Fe-Co-based metallic glass particles with 200-500 μm of diameter have been obtained by Pulsated Orifice Ejection Method (POEM). The XRD pattern of the particles shows only broad peaks without any crystalline peak. A bright field TEM image of the particles and the selected area diffraction patterns shows only halo patterns that indicate fully amorphous phase. DSC curve shows that supercooled liquid region was ΔT=48 K and a TTT curve can be constructed by isothermal DSC.