Development of a MAGLEV superconducting magnet for the Yamanashitest line in Japan: vibration characteristics and analysis for design

A high-performance and high-reliability magnetically levitated (MAGLEV) superconducting magnet (SCM) was developed. Its heat generation per unit time by the electromagnetic forces due to the spatially fifth ripple magnetic fields from levitation coils is under 2 W at the frequency range in which vehicles are levitated. The vibration mode of inner vessels that makes the largest contribution to heat generation in SCMs is clarified, the torsion mode. A modeling method to analyze SCM vibration, which considers the effect of the bogie frames of a vehicle, is examined, and heat generation in SCMs is calculated from the vibration of the inner vessel. Using the numerical analysis method, new SCMs combined with new bogie frames for the Yamanashi Test Line are designed. Good performance in vibration and heat generation of these SCMs is predicted by numerical analysis     

Experimental study on a quasi-optical mode converter for transforming the whispering-gallery mode into a circularly polarized hollow radiation beam

An experiment was carried out for transforming the 120 GHz-TE_12.2 whispering-gallery mode (WGM) into a circularly polarized hollow radiation beam. A hollow beam was formed by reflecting the WGM, which was radiated from a 16 mm radius circular waveguide cut, with an annular mirror having suitable local normal vectors. The experimentally observed field intensity profiles of the reflected wave were in good agreement with calculated results.     

Smart Ferrofluid with Quick Gel Transformation in Tumors for MRI‐Guided Local Magnetic Thermochemotherapy

Improved techniques for local administration of anticancer drugs are needed to reduce the side effects of chemotherapy owing to leakage of anticancer drugs from tumors and to enhance therapeutic efficacy. This study presents the development of smart ferrofluid that transforms immediately into a gel in tumors and generates heat in response to an alternating magnetic field (AMF), simultaneously releasing the anticancer drug. The smart ferrofluid, which is synthesized using less toxic magnetic materials (Fe₃O₄ nanoparticles), natural polysaccharides (alginate), and amino acids (cysteine), can also act as a contrast agent for magnetic resonance imaging (MRI). The ferrofluid also incorporates an anticancer drug (i.e., doxorubicin, DOX) via hydrogen bonds. AMF causes heating of gels prepared from the DOX‐containing ferrofluid, resulting in gel shrinkage and DOX release. In vivo experiments demonstrated that the ferrofluid transforms into a gel in the tumor, with the gel remaining in the tumor. Furthermore, magnetic thermochemotherapy using this ferrofluid inhibited tumor growth, while magnetic hyperthermia alone had only a marginal effect. Thus, the combination of magnetic hyperthermia and chemotherapy may be important for suppressing tumor growth. In summary, the ferrofluid presented here has the potential to facilitate MRI‐guided magnetic thermochemotherapy through a combination of endoscopic technologies in the future.     

Ceramic Dental Molds for the Precision Casting of Titanium and Titanium Alloys: I, Relationship between Particle-Size Distribution of Aggregates and Mold Expansion

A new ceramic dental mold can cast excellent Ti restoratives by controlling expansion due to the oxidation of additive metal particles. The packing structure of the metal and aggregate particles in the mold can be considered a function of the size distribution of the aggregate grains. An investigation of the expansion mechanism reveals three different relationships of void fraction versus linear thermal expansion for the molds at the high temperature under which oxidation of the metal particles occurs. Room-temperature casting, favorable for making high-quality Ti restoratives, can also be achieved by precisely controlling both the amount of additive metal powder and the compositional distribution of aggregate grain sizes in the mold.     

Toughening of Silicon Nitride Matrix Composites by the Addition of Both Silicon Carbide Whiskers and Silicon Carbide Particles

Si₃N₄ matrix composites reinforced by SiC whiskers, SiC particles, or both were fabricated using the hot-pressing technique. The mechanical properties of the composites containing various amounts of these SiC reinforcing materials and different sizes of SiC particles were investigated. Fracture toughness of the composites was significantly improved by introducing SiC whiskers and particles together, compared with that obtained by adding SiC whiskers or SiC particles alone. On increasing the size of the added SiC particles, the fracture toughness of the composites reinforced by both whiskers and particles was increased. Their fracture toughness also showed a strong dependence on the amount of SiC particles (average size 40 μm) and was a maximum at the particle content of 10 vol%. The maximum fracture toughness of these composites was 10.5 MPa·m^1/2 and the flexural strength was 550 MPa after addition of 20 vol% of SiC whiskers and 10 vol% of SiC particles having an average particle size of 40 μm. These mechanical properties were almost constant from room temperature to temperatures around 1000°C. Fracture surface observations revealed that the reinforcing mechanisms acting in these composites were crack deflection and crack branching by SiC particles and pullout of SiC whiskers.     

Supercritical fluid extraction of fungal oil using CO2, N2O,CHF3 and SF6

The extraction of oil from fungi (Mortierella ramanniana var.angulispora) was studied using carbon dioxide (CO₂), nitrous oxide (N₂O), trifluoromethane (CHF₃) and sulfur hexafluoride (SF₆) under supercritical conditions. The oil solubility was highest in SC-N₂O followed by SC-CO₂, while both SC-CHF₃ and SC-SF₆ showed poorer solvent power. The recorded oil solubilities at 333 K and 24.5 MPa were 2.3 wt% in N₂O, 0.48 wt% in CO₂, 0.0099 wt% in CHF₃ and 0.0012 wt% in SF₆. The oil solubilities in SC-N₂O and SC-CO₂ were measured over the pressure range 15.7–29.4 MPa and at temperatures ranging from 313–353 K. N₂O always showed greater solvent power than did CO₂ at the same temperature and pressure. The solvent power of a supercritical fluid increases with density at a given temperature, and increases with temperature at constant density. The change in neutral lipid composition of the extracted oil with the extraction ratio was measured. Free fatty acids or diglycerides were extracted more easily than triglycerides or sterol esters. The change in fatty acid composition was also measured. The proportion of γ-linolenic acid in the extract remained constant throughout the extraction.     

Capacitance-voltage characteristics of Semiconductor-Insulator-Semiconductor (SIS) structure

The ideal low- and high-frequency capacitance-voltage curves of a semiconductor(2)-insulator-semiconductor(1) (SIS) structure were first calculated with the insulator thickness, conductivity types and doping concentrations in semiconductor(1) and semiconductor(2) as parameters. The effects of fixed oxide charge and interface trap charge on the low and high frequency capacitance-voltage curves were also calculated. It was found that the fixed oxide sheet charge density with its centroid and the order estimation of the interface trap charge density with its effective type in addition to the insulator thickness, conductivity types and doping concentrations in semiconductor(1) and semiconductor(2) could be estimated from measured low and high frequency capacitance-voltage curves of an SIS structure.     

A family of infantile genetic agranulocytosis

A survey was performed of the mold flora in the air and on the surfaces inside twelve homes throughout four seasons. There were significant variations of the mold flora in homes associated with the outdoor spore count, various rooms, carpeting, central air-conditioning and pets. We conclude that homes may be a source of perennial mold exposure.     

Suppression of inducible nitric oxide synthase expression and amelioration of lipopolysaccharide-induced liver injury by polyphenolic compounds in Eucalyptus globulus leaf extract

Eucalyptus leaf extract (ELE) is rich in hydrolyzable tannins. We examined the effects of ELE and its constituents on lipopolysaccharide (LPS)-induced liver injury in mice. Mice fed a diet supplemented with 1% ELE were intraperitoneally administered LPS. Six hours later, the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were significantly lower in the ELE-supplemented mice than in the controls; LPS-induced hepatic inducible nitric oxide synthase (iNOS) expression was also suppressed. ELE lowered LPS-stimulated iNOS expression in cultured RAW 264.7 macrophages. Furthermore, the aglycones of hydrolyzable tannins, gallic acid (GA) and ellagic acid (EA), inhibited iNOS induction to a greater extent than did ELE (15-fold higher). When mice were fed a 1% GA or EA diet, the increase in the serum ALT and AST activities and hepatic iNOS expression in response to the LPS challenge were significantly attenuated. Thus, hydrolyzable tannins in ELE ameliorate LPS-induced liver injury.