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Carfilzomib is a medicine that was recently approved for the treatment of cancer of bone marrow (multiple myeloma) that comes back or does not respond to previous treatment (relapsed or refractory). Data gathered from the hospitals, where the medicine is commonly used, was used to generate evidence. We looked at how well carfilzomib works in Japanese participants and if it is safe. Overall, 63.5% of participants treated with carfilzomib had side effects and 37.7% had serious side effects. Death occurred in 3.1% of participants during the study. Decrease in bone marrow and blood cells, infections, heart and kidney disorder, liver failure or dysfunction, and high blood pressure occurred in 5% or more participants. In 46.5% of participants the tumors had disappeared or shrank. In Japanese participants, carfilzomib was found to be safe and effective treatment for cancer of bone marrow that comes back or does not respond to previous treatment.

Converging–diverging nozzles are common in rocket engine systems to increase the exhaust velocity and improve thrust performance. In this study, we focused on the acceleration of subsonic burned gas without a structural throat via detonation to realize a simple and compact engine. We developed and tested a rotating detonation engine (RDE) without a throat and with a diverging channel (constant diverging angle α=5 deg). Gaseous C2H4 and O2 were used as the propellants, and the mass flow rate ranged from 62 to 134 g/s in the combustion tests under low back-pressure conditions. We measured pressure and thrust, as well as high-speed imaging of self-luminescence of the combustion and imaging of the exhaust plume. The pressure at the exit was less than one-fifth of the maximum pressure in the RDE, significantly below the value for a sonic flow. The results suggested that the exhaust flow was supersonic, with values up to Mach 1.7, without the need of a converging section within the engine. In addition to the estimated Mach number from the measured pressure, the exhaust plume images coherently indicated the existence of supersonic exhaust.

A rotating detonation engine (RDE) generates a continuous thrust with one or more rotating detonation waves. Because of the velocity on the order of kilometers/second, the reaction zone is relatively small. Therefore, the RDE realizes a short combustion chamber length. However, the detonation waves induce an azimuthal motion of propellant, resulting in torque around the thrust axis. Because the motion does not contribute to the thrust, the torque is important in terms of performance loss. Herein, we conducted combustion tests with a six-axis force sensor to simultaneously measure 0.149±0.009 Nm torque and 48.1±0.9 N thrust. A comparison of detonation waves captured by high-speed camera revealed that the torque followed the direction and was offset when the waves existed in both of two directions simultaneously, which indicates the possibility of controlling the torque. Under a mass flow rate at 87±9 g/s and an equivalence ratio at 1.43±0.28, when the azimuthal component of shear force was 8.8±0.6% of the thrust, 0.77±0.10% of the total kinetic energy of the exit flow was distributed to the azimuthal component of velocity and did not contribute to the thrust. We therefore concluded that the effect of the azimuthal motion on the RDE’s performance was small.

To analyze a rotating detonation cycle (RDC) with burned gas backflow, simultaneous self-luminous visualization, pressure, and thrust measurements with gaseous ethylene and oxygen were performed. Three different geometric blockage ratios (bottom-wall-surface area to cross-sectional area of combustor) were set at 89.2 , 70.2 , and 51.7 % . The fuel and oxidizer mass flow rates and equivalence ratio were constant at 20.6 g / s , 41.2 g / s , and 1.7, respectively. During the combustion test, the single detonation wave rotated at 1557, 1459, and 1353 m/s, and the propagation speed increased proportionally for the geometric blockage ratio. The estimated fuel–oxidizer–based specific impulse was in the range of 148 ± 8 s , and the impact of the geometric blockage ratio and propagation speeds on this specific impulse was not confirmed. The hydrodynamic blockage ratio of the oxidizer injector due to the detonation wave was estimated using the oxidizer plenum pressure. It was found that the hydrodynamic blockage ratio linearly decreased with an increase in the geometric blockage ratio. This important trend suggests that the RDC operation is limited in the region of the lower geometric blockage ratio. It is also predicted that a reduction in the hydrodynamic blockage ratio while maintaining the geometric blockage ratio is required for stable RDC operation and achievement of pressure gain combustion. Moreover, the whole RDC structure including the burned gas back flow successfully visualized at the frame rate of 0.5 and 1 µs. The validity of estimated hydrodynamic blockage ratio was demonstrated by comparison with the visualization experiment. It was concluded that the hydrodynamic blockage ratio was primarily determined mainly by the time scale of the burned gas backflow.

The internal flow structures of detonation wave were experimentally analyzed in an optically accessible hollow rotating detonation combustor with multiple chamber lengths. The cylindrical RDC has a glass chamber wall, 20 mm in diameter, which allowed us to capture the combustion self-luminescence. A chamber 70 mm in length was first tested using C2H4single bondO2 and H2–O2 as propellants. Images with a strong self-luminescence region near the bottom were obtained, confirming the small extent of the region where most of the heat release occurs as found in our previous research. Based on the visualization experiments, we tested RDCs with shorter chamber walls of 40 and 20 mm. The detonation wave was also observed in the shorter chambers, and its velocity was not affected by the difference in chamber length. Thrust performance was also maintained compared to the longer chamber, and the short cylindrical RDC had the same specific impulse tendency as the cylindrical (hollow) or annular 70-mm chamber RDC. Finally, we calculated the pressure distributions of various chamber lengths, and found they were also consistent with the measured pressure at the bottom and exit. We concluded that the short-chamber cylindrical RDC with equal length and diameter maintained thrust performance similar to the longer annular RDC, further expanding the potential of compact RDCs., Available online 17 August 2020

This study evaluated the propulsion performance of a nozzleless, cylindrical rotating detonation engine (RDE). Using a C2H4–O2 mixture, the RDE was tested in a low-back-pressure environment at propellant mass flow rates of 8–45 g/s. In high-speed imaging of the self-luminescence within the combustor, rotating luminous regions were observed at mass flow rates above 22 g/s. Measured pressure distributions suggest that burned gas reached sonic velocity at the combustion chamber outlet. This paper proposes the structure of internal flow in the RDE and confirms that calculated pressure distribution based on the structure was close to the experimental distribution. This study also estimated the RDE’s thrust by pressure and momentum exchange and confirmed it by experimental measurement. Moreover, the theoretical thrust calculated under the assumption that exhaust is a sonic flow agreed with the load cell thrusts, suggesting that RDE combustion is perfectly completed inside the chamber. Specific impulses are 80–90% of specific impulses for ideal correct expanded flow for all mass flow rates, and its value was close to that of an annular RDE. In addition, RDE performance will increase by about 20% if the RDE is equipped with a divergent nozzle and the gas is correctly expanded to back pressure.

Fluorescent molecules based on a fluorinated isoxazole scaffold were synthesized and investigated for their photochemical properties. The introduction of a fluorine substituent into 3,5-diarylisoxazoles led to an increase of fluorescence intensity and exhibited a redshift in the emission intensity. α-Fluorinated boron ketoiminates (F-BKIs) were also synthesized via a ring-opening reaction of 4-fluoroisoxazoles and exhibited highly fluorescent luminescence and aggregation-induced emission (AIE), showing promise as a new fluorophore.

The multiple-ion-probe measurement method is a method to measure a propagating flame using ion probes installed on the wall surface of a combustion chamber. The dynamic behavior of the propagating flame along the wall surface can be regenerated from the dataset of flame signals from individual ion probes. Although this method only captures flames near the wall surface, the flame propagation behavior can be indirectly visualized. Because this method can attain very high temporal resolution, it can provide precise measurements of high-speed phenomena such as knocking in spark-ignition engines and detonation in detonation combustors. This study aimed to investigate the ability of a developed 64-channel multiple-ion-probe measurement system to characterize a propagating flame. To this end, three flames with substantially different propagation velocities were measured using the proposed multiple-ion-probe measurement system. During the experiments, methane–oxygen stoichiometric mixtures diluted with different amounts of nitrogen were used. The flame propagation velocity varied within the range of several m/s for a turbulent flame to 2.4 km/s for detonation by varying the dilution ratio of nitrogen. In the case where a mixture with a nitrogen mole fraction of 0.71 was used, a phenomenon of repeating stagnation and reacceleration of the propagating flame was observed. Furthermore, the phenomenon considered to be flame quenching was also observed near the wall. In the case of no dilution (nitrogen mole fraction = 0.00), multiple-ion probes with an installation interval of 1.5 mm indicated that the velocity fluctuated within the range of −500 m/s to +2000 m/s with respect to the Chapman–Jouguet detonation velocity of 2390 m/s. Experiments involving soot foil recording conducted in parallel confirmed that this velocity fluctuation was derived from the detonation cell structure and that micro-explosions in the detonation front could be captured using the multiple-ion-probe method.

The thermal expansion behaviors of few-layered graphene (FLG)/Al composites fabricated via spark plasma sintering and hot extrusion were evaluated. We demonstrated the first example of efficiently reducing the coefficients of thermal expansion (CTEs) of Al composites by incorporating FLG. The CTE of the Al matrix decreased from 26.72 × 10−6 K−1 to 25.53 × 10−6 K−1 with incorporating of merely 0.4 vol% of FLG. Due to the detachment of FLG-Al interface at elevated temperatures, the CTEs of the composites were slightly higher than those estimated by theoretical prediction. This result was further confirmed by the presence of hysteresis phenomenon of the cyclic expansion behavior of the FLG/Al composite. Moreover, the FLG exhibited a high constraining efficiency of ∼13, being more effective at lowering the CTEs of Al composites as compared to other traditional fillers. This work could be significant for guiding the design of high-performance graphene/Al composites for thermal management applications.

A high operating frequency of a pulse detonation engine is required to increase the thrust-to-engine weight ratio or thrust density. The semi-valveless pulse detonation cycle (PDC) proposed by Matsuoka et al. (2017) can achieve a high operating frequency exceeding several kilohertz. For achieving a higher operating frequency close to the upper limit of gas dynamics, it is necessary to minimize the process in which the buffer layer is applied to avoid self-ignition of the detonable mixture. Experiments were conducted, and a one-dimensional numerical model was developed to investigate the minimum thickness of the buffer layer and the required duration for the stable PDC operation. Ethylene was used as a fuel and pure oxygen as an oxidizer. The total length of two combustors with an inner diameter of 10 mm was 40 and 80 mm. Therefore, the thickness of the buffer layer of approximately 20 mm was suggested for the stable PDC operation. This result indicated that 10% of the duration of one PDC was required to prevent self-ignition (SI). In the failed PDC, the early and late SI were confirmed. Interestingly, high-frequency PDC operation with a short combustor can suppress late SI and results in a higher success rate with the same thickness of the buffer layer. Furthermore, a stable PDC operation of a 1916 Hz with a combustor with a total length of 40 mm was demonstrated.

Fabricating high-strength Al matrix composites without sacrificing their electrical conductivity is a critical issue in the design of Al-based conductors. Here, we demonstrate for the first time, an example of improving the interfacial load transfer and strength of few-layer graphene (FLG)/Al composites by an appropriate interfacial reaction. Monocrystalline Al4C3 nanorods that tightly conjoined the FLG platelets with the Al matrix were produced by manipulating the sintering temperature. As revealed by transmission electron microscopy and by a shear lag model that provides a quantitative estimate of the strengthening, the Al4C3 nanorods ensured an efficient load transfer at the FLG-Al interface, thereby giving rise to a considerable enhancement of strength in the composite. Moreover, the electrical conductivity is almost as high as that of pure Al, which could be a significant step toward the preparation of high-performance Al-based conductors.

For stoichiometric C2H4–O2 and C2H2–O2 mixtures with or without argon dilution, the processes of detonation diffraction have been investigated in a two-dimensional setup through high-speed schlieren imaging, with the characteristic length and the stability of detonation varied by regulating the initial pressure and argon mole fraction of the mixture. In particular, a length relevant to the process of supercritical diffraction (i.e., distance from the channel end corner to reflection point of the transverse detonation on the channel end face, reflection point distance in short) was deduced from obtained sequential schlieren images and analyzed. The reflection point distance can be idealized for the infinitely wide donor channel, and thus, it can be a parameter in which properties intrinsic to each detonable mixture are manifested. Experimental results showed that the reflection point distance was roughly inversely proportional to the initial pressure for identical mixtures and independent of the width of the donor channel at high initial pressures. For a certain combination of the fuel and oxidizer, correlations between the reflection point distance and the initial partial pressure of fuel were very similar regardless of the argon mole fraction. Critical conditions of the diffraction problem could be given for the ratio of the reflection point distance to the channel width, and it was suggested that the critical value lies in a range of 3–5 and does not significantly depend on the stability of the mixture., ファイル公開：2021/01/01

The MoSiBTiC alloy is one promising candidate for ultrahigh–temperature materials. However, it faces severe challenges in the machining of complex shapes because of its significant brittleness, high melting point, and stiffness. To overcome this challenge, we have successfully fabricated MoSiBTiC alloy parts via laser powder bed fusion (L-PBF). A combination of arc-melting and controllable high-energy ball milling (HEBM) was employed to prepare suitable MoSiBTiC powders for L-PBF. The evolution of powder morphology, constituent phases, and laser absorptivity, as well as particle size and distribution during HEBM, was investigated. Moreover, the effects of L-PBF parameters on the densification, microstructure, and mechanical performance of MoSiBTiC alloy builds were studied. A dense MoSiBTiC alloy, mainly consisting of a Mo solid-solution, Mo5SiB2, Mo2C, and TiC phases, was obtained at an energy density of 156 J mm−3 using the laser power of 70 W. Compared to the as-cast alloy, the L-PBF-processed MoSiBTiC alloy possessed more uniform and finer grain structures, while exhibiting a lower Vickers hardness due to the existence of internal microcracks. It was also proved that the small quantity of ZrO2 particles from HEBM processing was uniformly imbedded in L-PBF builds. This work may offer significant guidance for designing and producing complexly shaped refractory intermetallics with unique microstructures in ultrahigh–temperature applications.

Geometric throats are commonly applied to rocket combustors to increase pressure and specific impulse. This paper presents the results from thrust measurements of an ethylene/gas-oxygen rotating detonation engine with various throat geometries in a vacuum chamber to simulate varied backpressure conditions in a range of 1.1–104 kPa. For the throatless case, the detonation channel area was regarded to be equivalent the throat area, and three throat-contraction ratios were tested: 1, 2.5, and 8. Results revealed that combustor pressure was approximately proportional to equivalent throat mass flux for all test cases. Specific impulse was measured for a wide range of pressure ratios, defined as the ratio of the combustor pressure to the backpressure in the vacuum chamber. The rotating detonation engine could achieve almost the same level of optimum specific impulse for each backpressure, whether or not flow was squeezed by a geometric throat. In addition, heat-flux measurements using heat-resistant material are summarized. Temporally and spatially averaged heat flux in the engine were roughly proportional to channel mass flux. Heat-resistant material wall compatibility with two injector shapes of doublet and triplet injection is also discussed., Published online: 12 November 2018

We describe the critical condition necessary for the inner cylinder radius of a rotating detonation engine (RDE) used for in-space rocket propulsion to sustain adequate thruster performance. Using gaseous C2H4 and O2 as the propellant, we measured thrust and impulse of the RDE experimentally, varying in the inner cylinder radius ri from 31 mm (typical annular configuration) to 0 (no-inner-cylinder configuration), while keeping the outer cylinder radius (ro = 39 mm) and propellant injector position (rinj = 35 mm) constant. In the experiments, we also performed high-speed imaging of self-luminescence in the combustion chamber and engine plume. In the case of relatively large inner cylinder radii (ri = 23 and 31 mm), rotating detonation waves in the combustion chamber attached to the inner cylinder surface, whereas for relatively small inner cylinder radii (ri = 0, 9, and 15 mm), rotating detonation waves were observed to detach from the inner cylinder surface. In these small inner radii cases, strong chemical luminescence was observed in the plume, probably due to the existence of soot. On the other hand, for cases where ri = 15, 23, and 31 mm, the specific impulses were greater than 80% of the ideal value at correct expansion. Meanwhile, for cases ri = 0 and 9 mm, the specific impulses were below 80% of the ideal expansion value. This was considered to be due to the imperfect detonation combustion (deflagration combustion) observed in small inner cylinder radius cases. Our results suggest that in our experimental conditions, ri = 15 mm was close to the critical condition for sustaining rotating detonation in a suitable state for efficient thrust generation. This condition in the inner cylinder radius corresponds to a condition in the reduced unburned layer height of 4.5–6.5., Available online: 11 August 2018. ファイル公開：2020-08-11

As a novel detonation combustor that differs from a pulse and a rotating detonation engine, a reflective shuttling detonation combustor (RSDC), in which detonation waves shuttle repeatedly, was proposed. In a fan-shaped two-dimensional combustor, detonation waves propagate, repeating attenuation and re-ignition by a shock reflection at the side wall. In the demonstration experiment, chemiluminescence visualization and pressure measurement with ethylene–oxygen mixture were conducted at the same time. As the result, a single shuttling wave coupled with pressure rise was observed in the combustor. The tangential velocity of the wave was 1526 ± 12 m/s and approximately 60% of the estimated Chapman–Jouguet velocity of 2513 m/s. The ratio of pressure in front of the wave to one behind the primary wave or the reflected wave was in good agreement with one-dimensional shock theory, and it was suggested that the rapid reaction behind the reflected shock wave sustained the continuous propagation of the shock wave., ファイル公開：2021-01-01

Despite the ultrahigh intrinsic strength of multiwalled carbon nanotube (MWCNT), the strengthening effect on ceramic matrix composite remains far from expectation mainly due to the weak load transfer between the reinforcement and ceramic matrix. With the assistance of the in situ pullout test, it is revealed that the liquid‐phase sintering (LPS) can serve as a novel strategy to achieve effective load transfer in MWCNT reinforced ceramic matrix composites. The YAlO3 formed liquid phase during spark plasma sintering of SiC composite greatly facilitates radical elastic deformation of MWCNT, leading to highly increased interfacial shear strength (IFSS) as well as interlayer shear resistance (ISR) of nested walls. The liquid phase with superior wettability can even penetrate into the defects of MWCNT, which further increases the ISR of MWCNT. Moreover, the first‐principles calculation indicates that the oxygen terminated YAlO3 phase displays much stronger bonding compared with SiC matrix, which is also responsible for the large IFSS in the composite. As a result, as high as 30% improvement of bending strength is achieved in the composite with only 3 wt% MWCNT in comparison to the monolithic ceramic, manifesting the unprecedented strengthening effect of MWCNT assisted by LPS., The liquid‐phase sintering can significantly improve the load transfer between multiwalled carbon nanotube and SiC ceramic matrix by increasing the interfacial shear strength and interlayer shear resistance, giving rise to unprecedented strengthening effect of 30% with filler fraction of only 3 wt%. The finding provides a strategy for designing highly strong ceramics reinforced by low‐dimensional reinforcements.

International audience; Aluminum (Al) matrix composite materials reinforced with graphite flakes (GF) and pitch-based carbon fibers (CF) were fabricated by solid–liquid phase sintering with a small amount of Aluminum–Silicon eutectic alloy (Al-12 wt%Si). The amount of Al–Si is optimized for a carbon content of 50 vol% in order to achieve, in the plane of GF reinforcement, a higher thermal conductivity (TC) and a lower coefficient of thermal expansion (CTE) compared to identical composite material fabricated by conventional powder metallurgy route. Al/(GF + CF) composite materials were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray microscopy and X-ray tomography in order to highlight the distribution of the Al–Si liquid phase and the formation of a carbon network in the aluminum matrix. A small amount of CF allows to control the through-plane CTE without affecting significantly the in-plane TC of the Al-C composites. The (GF + CF) mixture and the solid–liquid phase sintering allow to achieve a TC of 410 W/m K (in-plane direction) and a CTE of 2.4 × 10−6/K (trough-plane direction), which is, for example, applicable for lightweight heat sink material.

A reflective shuttling detention combustor (RSDC) is a two-dimensional combustor with two reflection walls. Unlike a rotating detonation combustor (RDC), an RSDC can visualize the entire area of the combustor via an optical technique. In addition, the RSDC can reproduce the counter-rotating detonation mode in RDC. In present study, CH* luminescence and schlieren image were observed to investigate the dynamics of the RSDC. The reflective wall distance was set to 45 mm (Type L) and 25 mm (Type S). As the results, the wave speed of 1226 ± 64 m / s in the single wave mode in Type S was 76% of that in Type L. It was found that the detonation propagation speed decreased with a reduction in the reflection wall distance. Superimposing the luminescence images on the schlieren images revealed that the mixture was mainly burned by deflagration behind shock wave. In addition, the experimental mixture fill height was in good agreement with model in which the mixture filling process was temporarily stopped by detonation and refilled at a constant speed. Using the maximum fill height obtained by the model, it was found that the detonation mode was in the region of 3 ± 0.6 of the dimensionless quantity (the reflection wall distance divided by the wave number and maximum value of the mixture fill height).

3D-networks of few-layer graphene (FLG) platelets at grain boundaries, sandwiched between thin amorphous Al2O3 layers, were fabricated by spark plasma sintering (SPS) of graphene oxide (GO)/Al mixed powders. The GO was prepared by a modified Hummers’ method, and was thermally reduced to FLG simultaneously during SPS densification. Subsequent plastic flow of the Al matrix during the hot extrusion process caused the destruction of this structure, rearranged the FLG platelets individually into the uniaxial direction, and made them incorporate in the Al matrix. Observations by high-resolution transmission electron microscopy proved the existence of a direct-contact interface between the FLG and the Al matrix without any interfacial compounds, and revealed that the Al matrix featured a fairly low dislocation density. Consequently, the mechanical strength of Al matrix was noticeably enhanced by FLG incorporation, agreeing with the potential strengthening effect predicted by the load transfer mechanism.

A strategy utilizing carbon nanotubes (CNTs) was put forward to synthesize in situ TiC/Mo-based composites via laser powder bed fusion (laser PBF). The functionalized CNTs were dispersed with MoTiAl powders under electrostatic attraction by heteroagglomeration. During laser PBF, individual CNTs reacted with Ti elements and were completely transformed into monocrystalline TiC. Those TiC reinforcements were homogeneously dispersed and intimately contacted the matrix, giving rise to the morphological evolution of a MoTiAl matrix from the nearly columnar to fine equiaxed grains as well as improved mechanical performance. Our finding offers significant guidance for designing and producing advanced Mo-based composites in the application of heat-resistant materials. Keywords: Laser powder bed fusion (laser PBF), Metal matrix composites (MMCs), Carbon nanotubes, Molybdenum, Microstructure

Periodic lines with intervals ranging from ∼220 μm down to ∼27 μm were fabricated on the surface of Zr55Cu30Al10Ni5 metallic glass ribbon and disk samples by laser irradiation. The X-ray diffraction results indicated that both oxides (monoclinic ZrO2, tetragonal ZrO2) and crystallites (Cu10Zr7, NiZr2) existed together with the amorphous phase on the surface of the laser-patterned metallic glass samples. The energy-dispersive X-ray spectroscopy of a cross section of a disk sample clearly showed that high amounts of aluminum (292% of the nominal composition) and oxygen were present in the laser-irradiated area, suggesting that Al2O3 formed on the surface of the laser-irradiated region. Reflective diffraction spots were observed from the fine grids with a grating period of ∼27 μm, indicating the excellent periodicity and accuracy of the pattern in two dimensions on the surface of the metallic glass substrates. Calculation of the grating period using Bragg's law confirmed that the spots originated from the periodic patterns of the laser-irradiated lines. Along the lines, pairs of ridges and hollows with a height/depth of ∼0.5 μm were observed; such specific morphology generated the diffraction spots as a reflective grating. We observed structural color gradation from the periodic fine grids under a fluorescent light. The present study showed that it is possible to prepare optical gratings on the surface of metallic glasses by laser irradiation more cheaply and easily than by conventional imprinting.

Accepted: 2017-10-12, 資料番号: SA1180307000

Laser powder bed fusion (PBF) offers many technological opportunities for producing high-performance composite parts with tailored structures. However, fabrication of suitable composite powders possessing homogenous dispersion, good flowability, suitable particle size and distribution is a prerequisite and main challenge currently faced. In this study, a novel strategy was developed to prepare nanoceramic/metal powders by using acid-treated carbon nanotubes (ATCNTs) as an agent. In detail, a 3 wt% ATCNT/Al2O3 colloid, in which the negatively-charged ATCNTs were partially covered with positively-charged Al2O3 nanoparticles under electrostatic attraction, was obtained by heteroagglomeration; subsequently, the uncovered surface areas of ATCNTs were intimately bonded to the positively-charged MoTiAl powders during their mixing. This ATCNT bridging made individual Al2O3 uniformly wrap on the surface of MoTiAl without aggregation. The Al2O3-coated MoTiAl powders remained similar in shape, particle size, and distribution to uncoated ones, simultaneously showing higher laser absorptivity due to an increased surface roughness. The PBF-processed Al2O3-ATCNT/MoTiAl composite was dense, in which Al2O3 nanoparticles were homogenously dispersed and intimately contacted with MoTiAl, giving rise to an increase in the hardness of the matrix. Keywords: Laser powder bed fusion, Metal matrix composites (MMCs), Carbon nanotubes, Dispersion, Laser absorptivity

形態: カラー図版あり, Physical characteristics: Original contains color illustrations, 資料番号: PA1810035000

Amorphous Fe76Si9B10P5 particles were fabricated by a container-free solidification process and subsequent annealing, and their structural and magnetic properties were investigated by X-ray diffraction analysis, transmission electronic microscopy, and vibrating sample magnetometry. The annealing induced the nanocrystallisation of α-Fe and Fe-B compounds. The proportions of the different crystalline phases formed were dependent on the annealing temperature. The saturation magnetisation of the single particles was higher than that of the samples prepared by a conventional quenching process; this was attributable to the higher homogeneity of the nanocrystalline grains of the former as well as their higher α-Fe to Fe-B compound ratio.

Periodic lines, approximately 15-μm-wide and separated by several hundred micrometers, were prepared on the surface of Zr 55 Cu 30 Al 10 Ni 5 metallic glass by scanning a focused laser beam across the samples in air. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) suggested that the lines produced by the focused laser beam consisted of localized metal oxides (tetragonal ZrO 2 , monoclinic ZrO 2 ) and crystallites (Cu 10 Zr 7 ), which was in contrast to the amorphous substrate. The electron backscatter diffraction (EBSD) also confirmed the successful patterning of the lines which was mainly composed of the fine ZrO 2 grains. The energy dispersive X-ray spectroscopy (EDS) mapping clearly exhibits that high amounts of zirconium (161% of the nominal composition) as well as oxygen (58.9%) and a certain amount of aluminum (80% of the nominal composition) were presented in the beam-scanned area. The Auger electron spectroscopy (AES) was also conducted to see the atomic percentage from the top surface to the depth direction and showed that the created oxides were thermally stable and therefore oxidization cannot proceed with increasing the number of laser scan. We confirmed that the laser irradiation method has a large degree of freedom for designing patterns, such as interdigital, dots, and letters because of the precise control over the scanning stage.

In order to explore the possibility of using carbon nanotube (CNT) to introduce and control the temperature coefficient of resistance (TCR) of metal matrix composite, relatively thick and short multi-walled CNTs (MWCNTs) were introduced in the metal matrix with in-situ formation of chromium carbide (Cr7C3) at the CNT/copper (Cu) interface. We demonstrate that incompatible properties such as electrical conductivity and TCR can be achieved simultaneously by introducing MWCNTs in the Cu matrix, with control of the interfacial resistivity using the MWCNT/Cr7C3–Cu system. High electrical conductivity of 94.66 IACS and low TCR of 1,451 10–6 °C−1 are achieved in the 5 vol.% MWCNT–CuCr composite. In-situ formation of Cr7C3 nanostructures at the MWCNT/Cu interface by reaction of diffused Cr atoms and amorphous carbon of MWCNTs would assist in improving the electrical properties of the MWCNT–CuCr composites.

International audience; Iron-ferrite composites fabricated by powder metallurgy processes were studied for electromagnetic and large band microwave absorption applications. The sintering behavior of such composites is not well-understood, and these materials have been found to lose their magnetic properties or mechanical properties. Different systems of Fe/NiZn ferrite composites were investigated in order to better understand the chemical reactions that occur between oxide spinel and iron particles during the fabrication process. Three different systems, two models and one reference material were studied to analyze the chemical reactions in the aforementioned fabrication process. The first model consisted of iron films deposited by Physical Vapor Deposition (PVD) onto an NiZn-ferrite substrate. The reference material was made of a mixture of hot pressed iron and ferrite powders. In the second model, a SiO2 layer was deposited by PVD onto the NiZn-ferrite substrate, followed by iron deposition by PVD to study the role of SiO2 as a diffusion barrier. The materials were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), dilatometry, electron probe microscopy analysis (EPMA) and X-ray diffraction (XRD). For the Fe/NiZn ferrite systems, the experimental results showed (i) an oxido-reduction reaction above 600 °C that produced FeO and FexNi1-x phases and (ii) a diffusion process of Ni and Zn. The combination of diffusion and oxido-reduction reaction induced the total consumption of the initial phase and a considerable decrease in magnetic properties. By adding a silica layer between the iron and ferrite layers, the redox interfacial reaction and iron diffusion were prevented at temperatures up to 800 °C.

The thermal expansion response of multi-walled carbon nanotube (MWCNT) reinforced Al matrix composites was employed to discuss the improvement of the load transfer at the interface between the MWCNTs and the Al matrix. An aluminum carbide (Al4C3) nanostructure at the end of the MWCNTs, incorporated in the Al matrix, was produced by appropriate heat-treatment. The stress contrast around the Al4C3 observed in the high-resolution transmission electron microscopy (HRTEM) image revealed the evidence of a trace of friction, which would lead to the enhancement of the anchor effect from the Al matrix. This anchor effect of Al4C3 may hinder the local interfacial slippage and constrain the deformation of the Al matrix. As a result, the thermal expansion behavior became linear and reversible under cyclic thermal load. It is concluded that the formation of Al4C3 could effectively enhance the load transfer in MWCNT/Al composites. The yield strength of MWCNT/Al composites was substantially increased under the appropriate quantity of Al4C3 produced at the MWCNT-Al interface by precisely controlled heat-treatment.

International audience; Aluminum matrix composites reinforced with carbon fibers or diamond particles have been fabricated by a powder metallurgy process and characterized for thermal management applications. Al/C composite is a nonreactive system (absence of chemical reaction between the metallic matrix and the ceramic reinforcement) due to the presence of an alumina layer on the surface of the aluminum powder particles. In order to achieve fully dense materials and to enhance the thermo-mechanical properties of the Al/C composite materials, a semi-liquid method has been carried out with the addition of a small amount of Al-Si alloys in the Al matrix. Thermal conductivity and coefficient of thermal expansion were enhanced as compared with Al/C composites without Al-Si alloys and the experimental values were close to the ones predicted by analytical models

The artifact volume generated in magnetic resonance (MR) images was quantitatively evaluated to investigate how artifact behavior correlates to the magnetic susceptibility and volume of an implanted metal device. For this, a new low-magnetic-susceptibility Zr-14Nb alloy was compared with two conventional dental alloys, Ti-6Al-7Nb alloy and Co-Cr-Mo alloy, using spherical specimens of each alloy prepared with four different diameters. Then, MR images were recorded under fast spin echo and gradient echo conditions, from which the artifact volume was measured. The artifact volume decreased with the magnetic susceptibility, volume, and mass of the specimens, and significant linear correlations were observed. The artifact volume can be estimated by the equations presented here; nevertheless, further studies are necessary to interpret the influence of some important factors (e.g., imaging conditions, shape, and orientation) to predict the artifact volume more precisely.

Naldemedine is a peripherally acting μ‐opioid‐receptor antagonist for the treatment of opioid‐induced constipation. Two phase 1 single‐dose studies investigated the pharmacokinetics and safety of a 0.2‐mg oral dose of naldemedine in subjects with renal impairment (mild, n = 9; moderate, n = 9; severe, n = 6; and end‐stage renal disease, n = 8) or hepatic impairment (mild or moderate, n = 8 each) and demographically matched healthy subjects with normal renal and hepatic function (n = 8, both studies). Pharmacokinetic assessments indicate that dose adjustments for naldemedine are not necessary for subjects with any degree of renal impairment or for subjects with mild or moderate hepatic impairment. In subjects with renal impairment compared with healthy subjects with normal renal function, the geometric mean ratios of naldemedine area under the concentration‐time curve (AUC0‐inf) ranged from 82.8% (90%CI 69.5% to 98.6%) to 137.8% (90%CI 114.0% to 166.5%). Renal clearance decreased with reduced renal function (normal function 1.3 L/h; mild impairment 1.1 L/h; moderate impairment 1.0 L/h; severe impairment 0.5 L/h), and only 2.7% of naldemedine was removed by hemodialysis. In subjects with hepatic impairment compared with healthy subjects with normal hepatic function, the geometric mean ratio of AUC0‐inf ranged from 82.8% (90%CI 65.7% to 104.5%) to 105.2% (90%CI 83.4% to 132.6%). Naldemedine was well tolerated in both healthy subjects and subjects with renal or hepatic impairment, and reported adverse events were generally consistent with the known safety profile.

Hikikomori has been recognized as a significant social issue in Japan. It is a Japanese term that refers to young people (aged 18-39 years) who have been in an asocial state of social withdrawal and social isolation for over six months. The Cabinet Office of Japan suggests that the number of hikikomori youth has reached approximately 700,000 and is still growing. In addition, recent surveys suggest that hikikomori has a prolonged influence, such that more than 610,000 middle-aged people (aged 40-65 years) have remained in a hikikomori state which began at a younger age. The major challenge of this issue facing experts is that Hikikomori individuals usually repulse external support or interventions, either consciously or unconsciously. Hence, psychological therapies reliant on external interventions have inevitable limitations in curing hikikomori. Our methodology of C-BED (Community-Based Enterprise Development), on the other hand, has proven effective in overcoming this challenge, based on the results of our pilot study supported by Japanese NGO and TOYOTA Foundation. C-BED is a peer-to-peer learning process in which hikikomori share their thoughts with peers in similar situations through online dialogues. In developing the original program, we adopted the Dialectic Behavior Therapy (DBT) to the C-BED and produced 10 online modules for participants to interact by using online SNS group chat. The results of the online workshops (online C-BED) for five Hikikomori youth suggested that their psychological anxiety has been decreased and their willingness to participate socially has been strengthened after attending a 3-course module. In addition, C-BED has incomparable advantages in approaching hikikomori in remote areas at a meager cost, and in bringing positive changes to those who are struggling with psychological problems, no matter their cultural or economic backgrounds. &nbsp

In this study, we evaluated the thermal stability and fragility of Fe 76 Si 9 B 10 P 5 supercooled liquid by using micrometer-scale particles prepared via a container-less solidification process. After construction of time-temperature-transformation (TTT) diagram of crystallization by means of isothermal DSC under various temperatures, we could successfully measure the viscosity of the particles in the supercooled liquid region by employing the single particle compressive test (SPCT). It is revealed that the temperature dependency of viscosity cannot be well fitted by the Vogel–Fulcher–Tammann (VFT) formula but can be fitted by an Arrhenius plot. The Angell plot indicates that the apparent fragility is higher than that of SiO 2 and the fabricated particles have hetero-amorphous structures composed of high-density nanoscale clusters dispersed uniformly in a glassy matrix phase.

The Codex Alimentarius Commission has recently adopted maximum levels for inorganic arsenic (As; in 2014) and total cadmium (Cd; in 2006) in polished rice grains to maintain food safety and to decrease the risk to human health. As rice is a staple crop in Japan and monsoon Asian countries, reducing concentrations of As and Cd in rice is an urgent matter. In flooded conditions, Cd concentration in soil solution decreases whereas As concentration increases. Therefore, we aimed to evaluate the efficiency of iron-bearing materials to decrease As concentration in soil solution and rice (Oryza sativa L.) grain under submerged cultivation, while also considering Cd concentration. In experiments conducted in paddy fields in six regions, As concentrations in the soil solution during the cultivation period decreased in the following order: control (REF) > steel converter furnace slag (SCS) > non-crystalline iron hydroxide (FH) > zero-valent iron (ZVI). The concentrations of As in brown rice were in the same...

A novel Mo-based composite with simultaneously improved mechanical and oxidation properties was fabricated by laser powder bed fusion (L-PBF), using uniform Al2O3-nanoparticle-decorated MoTiAl powders bridged by functionalized carbon nanotubes. A tight ceramic coating ∼2.57 μm in thickness consisting of an α-Al2O3 matrix with dispersed TiC particles was formed on the surface of the Al2O3-CNT/MoTiAl composite, which has been proved to effectively increase resistance to oxidation at 1173 K. Meanwhile, the nanoparticles were homogenously dispersed and tightly contacted with the matrix, giving rise to an enhanced Vickers hardness. This work shed light on designing and producing high-performance Mo-based composites for application to ultrahigh-temperature materials.