Electrically Conductive CNT-Dispersed Silicon Nitride Ceramics

Carbon nanotube (CNT)-dispersed Si₃N₄ ceramics with electrical conductivity were developed based on the lower temperature densification technique, in which the key point is the addition of both TiO₂ and AlN as well as Y₂O₃ and Al₂O₃ as sintering aids. This new ceramic with a small amount of CNTs exhibits very high electrical conductivity in addition to high strength and toughness. Since Si₃N₄ ceramics with Y₂O₃–Al₂O₃–TiO₂–AlN were originally used as a wear material, electrically conductive Si₃N₄ ceramics are expected to be applied for high-performance static-electricity-free bearings for aerospace and other high-performance components.     

Oxygen pressure measurements of silica saturated Fe-O-SiO2 melts by the emf method using zirconia solid electrolyte

The thermodynamic properties of silica-saturated iron silicate slags have been studied from oxygen partial pressure measurements using a solid electrolyte galvanic cell. The oxygen activity in molten silver bath equilibrated with iron silicate slags was determined by the following cell type, Pt, Ni-NiO/O=/slag-Ag(O), LaCrO₃, Pt at temperatures between 1473 and 1573 K for the slags ranging in compositions from iron saturation to magnetite saturation. The oxygen partial pressures obtained in this investigation were in good agreement with those given by the previous study using the CO-CO₂ gas equilibrium method. The data showed that the Fe⁺⁺⁺/Fe⁺⁺ ratio is proportional toP _{o 2} ^¼     

Titanium powder production by TiCl4 gas injection into magnesium through molten salts

A process to produce titanium powder continuously is proposed and its applicability is examined experimentally. The method is based on the chemical reaction in the conventional Kroll reduction process; however, TiCl₄ gas is injected into molten salt on which a molten magnesium layer is floated as the reductant. Bubbles of gaseous TiCl₄ can be reacted at the lower surface of the liquid Mg layer, while TiCl₄ gas reacts on the upper surface in the Kroll process. The fine Ti particles produced in this study were well separated from magnesium and could be recovered from the bottom of the molten salts. The particles were small and fine enough for use in powder metallurgy, while congregated lumps of about 20 μm in size are obtained by the Kroll process. The composition of molten salts and an operation temperature above 1073 K did not affect the morphology of the Ti particles, if suitable material for the reaction vessel was chosen.     

Reappraisal of Size Effect of Bearing Capacity from Plastic Solution

A simplified method for estimating the ultimate bearing capacity of surface footings on sand is described with special attention to the dependency of the angle of internal friction of sand on confining stress. An extended slip line method is developed, in which the dependency of the angle of internal friction on the confining stress is formulated from results of conventional triaxial compression tests for various sands. Based on results from a comprehensive series of calculations employing the extended slip line method, the writers reappraise size effects on bearing capacity and investigate the relationship between strength parameters of sand and size effects on bearing capacity. A modified formula and several diagrams that provide a simple estimation method are proposed to consider size effects on bearing capacity. A comparison between estimations using the formula and ultimate bearing capacities measured from several series of centrifuge tests demonstrates the practicability of the proposed method for both strip and circular footings.     

Proposal of Asynchronous Time Division Multiple Access Radio Highway Using Chirp Multiplexing Transform

Asynchronous TDMA bus-link systems using chirp multiplexing transform(CMT) are proposed for radio highway networks to provide the flexibleconstruction of fiber-optic radio access networks and thepossibility of the universal use of these networks among future diverseradio services. The CMT equipped at the radio base station performs twofunctions. One is the conversion of FDM multiple radio services intosignals with a TDMA format and the other is the time compression ofthe generated signal in order to allow asynchronous access. As aresult, the proposed systems can realize the unified transmission ofmultiple radio services and the switching of them in the optical stage(photonic routing) in the networks according to the type of radioservice. The realization of such photonic routing of the radio servicewould greatly benefit the goal of a seamless and universalnetwork available to different types of radio service. Therelationship between the pulse-loss probability performance and thecall-blocking probability performance is theoretically analyzed. Theeffect on the performance of traffic partiality in the coveredarea and the way the performance can be improved are theoreticallyinvestigated. Finally, one of the ways to determine the network sizecovered by a bus link and the number of connected radio base stationsis introduced.     

Stability of the molten globule state of a domain-exchanged chimeric protein between human and bovine {alpha}-lactalbumins

A domain-exchanged chimeric     

Production of peritrichate bacterionanofibers and their proteinaceous components by Acinetobacter sp. Tol 5 cells affected by growth substrates

The toluene-degrading bacterium Acinetobacter sp. Tol 5 is highly adhesive through cell-surface nanofibers. Previously, we identified two morphologically distinct nanofibers on Tol 5 cells, namely, nonperitrichate anchor-like and peritrichate pilus-like nanofibers. In the present study, the application of improved electron microscopy techniques enabled discrimination of three distinct types of peritrichate nanofibers on Tol 5 cells. Interestingly, production of these nanofibers was affected by the available growth substrate. Thick, long, straight nanofibers a, which were present on cells grown on toluene, lactate, and ethanol, were not observed on cells grown on triacylglycerol (TAG). In contrast, cells grown on TAG were covered with long, curved nanofibers c, which only existed sparsely on cells grown on toluene, lactate, and ethanol. Thin, short, straight nanofibers b were found densely covering the margin of cells grown on all four growth substrates. SDS-PAGE of Tol 5 cell-surface proteins detected a protein of 17.5 kDa that was expressed at a high level on ethanol, but was undetectable on TAG. Conversely, a 26 kDa protein was identified that was exclusively expressed on TAG, but was only faintly expressed by cells grown on the other substrates. Based on N-terminal amino acid sequences, the 17.5 and 26 kDa proteins were identified as the major subunits of type 1 and Fil pili, respectively, which are typical bacterionanofibers. From these results, we deduced that nanofibers a and c are type 1 and Fil pili, respectively. The adhesiveness of Tol 5 cells was low only when they were grown on TAG.     

Adsorptive removal of fluoride from aqueous solution using orange waste loaded with multi-valent metal ions

Adsorption gels for fluoride ion were prepared from orange waste by saponification followed by metal loading. The pectin compounds contained in orange waste creates ligand exchange sites once it is loaded with multi-valent metal ions such as Al³⁺, La³⁺, Ce³⁺, Ti⁴⁺, Sn⁴⁺, and V⁴⁺ to be used for fluoride removal from aqueous solution. The optimum pH for fluoride removal depends on the type of loaded metal ions. The isotherm experiments showed the Langmuir type monolayer adsorption. Among all kinds of metal loaded gels tested, Al loaded gel appeared to exhibit the most favorable adsorption behavior. The adsorption kinetics of fluoride on loaded gel demonstrated fast adsorption process. The presence of NO₃⁻, Cl⁻ and Na⁺ ions has negligible effect on fluoride removal whereas SO₄²⁻ and HCO₃⁻ retarded the fluoride removal capacity in some extent. Fluoride removal at different adsorbent doses showed that fluoride concentration can be successfully lowered down to the acceptable level of environmental standard. The fluoride adsorption mechanism was interpreted in terms of ligand exchange mechanism. The complete elution of adsorbed fluoride from the gel was successfully achieved using NaOH solution.     

Antihypertensive mechanism of a peptide-enriched soy sauce-like seasoning: the active constituents and its suppressive effect on renin-angiotensin-aldosterone system

We previously reported that a peptide-enriched soy sauce-like seasoning called fermented soybean seasoning (FSS) demonstrated antihypertensive effects both in spontaneously hypertensive rats (SHR) and Dahl salt-sensitive rats. Angiotensin I-converting enzyme (ACE) inhibitory substances (9 kinds of dipeptides and a nicotianamine) were identified from FSS. In the present study, we clarified the mechanisms underlying the antihypertensive effects of FSS in SHR. FSS was divided into the nicotianamine fraction and the peptide fraction. The peptide fraction was found to exert a more prevalent antihypertensive effect than the nicotianamine fraction in SHR. Among the peptides, we identified Gly-Tyr and Ser-Tyr as the 2 primary substances in FSS that contributed to the antihypertensive effect in SHR. These peptides were neither degraded by acid nor gastrointestinal proteases, and were absorbed into the circulating blood. FSS (2000 mg/kg) exerted ACE inhibitory activity in the lung of rats and provided a decrease (P= 0.0067) in the level of serum aldosterone after a single oral administration in SHR, resulting in the antihypertensive effect. The antihypertensive mechanism was found to be similar to therapeutic ACE inhibitors and other food-derived ACE inhibitory peptides, which are in wide use and are recognized as safe.     

Infrared multiple photon dissociation spectroscopy and computational studies of O-glycosylated peptides

The infrared multiple photon dissociation (IRMPD) spectra of O-glycosylated peptides in the gas phase were studied in the IR scanning range of 5.7-9.5 μm. Fragmentation of protonated and sodiated O-glycopeptides was investigated using electrospray ionization (ESI) Fourier-transform ion cyclotron resonance (FTICR) mass spectrometry (MS) with a free electron laser (FEL). FEL is used in the IRMPD technique as a tunable IR light source. In the IRMPD spectroscopic analysis of the protonated O-glycopeptide, fragment ions of the b/y and B/Y types were observed in the range of 5.7-9.5 μm, corresponding to the cleavage of the backbone in the parent amino acid sequence and glycosyl bonds, whereas the spectra of the sodiated glycopeptide showed major peaks of photoproducts of the B/Y type in the range of 8.4-9.5 μm. The IRMPD spectra of the O-glycopeptides were compared with simulated IR spectra for the structures obtained from the molecular dynamics.