Induction of salt tolerance in Bacillus subtilis IFO 3025

Salt tolerance was induced in Bacillus subtilis IFO 3025 cells when a moderate osmotic stress was imposed by incubation in the presence of compatible solutes and 0.5 M NaCl or 0.8 M sorbitol. The optimum condition for inducing salt tolerance was observed when the cells were incubated in a solution containing 5 mM glutamate, 2.5 mM KCl, and 0.5 M NaCl or 0.8 M sorbitol. After 60 min incubation, the cells were able to form colonies on an agar plate with high salinity. It was confirmed that the cells acquired salt tolerance by accumulating glutamate and potassium ions in the cytoplasm as the main solute and ion, respectively.     

Design of novel biomimetic polymer gels with self-oscillating function

We report a novel biomimetic gel that undergoes autonomous swelling-deswelling oscillations without on-off switching of external stimuli, similar to heartbeat. The mechanical oscillation of gel was produced via oscillating chemical reaction, called the Belousov-Zhabotinsky (BZ) reaction. We have prepared an ionic gel consisting of the cross-linked poly(N-isopropylacrylamide) chain to which ruthenium tris(2,2′-bipyridine), a catalyst for the BZ reaction, was covalently bonded. The BZ reaction occurring within the gel matrix generates periodic redox changes of the catalyst moiety. This chemical oscillation is converted into the mechanical oscillation of the polymer network. As a result, the gel exhibits a periodical swelling-deswelling change. The self-oscillating behaviors of the gel were investigated in detail. When the gel size is smaller than the chemical wavelength, the redox change occurs homogeneously in the gel. In this case, the volume change is isotropic and the mechanical oscillation synchronizes with chemical oscillation without a phase difference. The period and amplitude can be controlled by changing the outer substrate concentrations. In the case of rectangular shape, chemical wave propagates along the length of the gel. The wavelength and velocity depend on the reaction rate of autocatalytic process as well as the diffusivity of the activator. The dynamic behavior that locally shrunken (or swollen) parts propagate was observed, similar to the peristaltic motion of worms. By using lithography technique, a ciliary motion actuator made of the gel has been demonstrated. These self-oscillating gels may be useful in a number of important applications to intelligent biomaterials such as pulse generator or chemical pacemaker, auto-mobile actuators or micropumps with peristaltic motion, device for signal transmission, etc.     

Deposition of titanium nitride films onto silicon by an ion beam assisted deposition method

Titanium nitride (TiN) films were deposited onto silicon wafers using an ion beam assisted deposition (IBAD) method with an electron cyclotron resonance (ECR) ion source for ionizing the nitrogen (N₂) gas under a condition of high nitrogen ion to titanium neutral ratio. The deposition rate of the TiN films was strongly dependent on the evaporation rate, d_Ti, of Ti metal and decreased with increasing nitrogen ion current. The deposition rate can be approximated as d=βd_Ti?_N2/{1/k+?_N2}−αI, where β, k and α are proportional constants, ?_N2 is the sum rate of neutral and ionized nitrogen impinging onto the substrate, and I is the nitrogen ion current.     

Multi‐primary‐color LCD: Its characteristics and extended applications

Abstract— The development of multi‐primary‐color (MPC) display systems is one of the big paradigm shifts in recent display technologies and induces new potentials of display devices. The development of MPC display systems for different goals is briefly reviewed. Especially, by employing MPC systems, it is possible to reproduce the real material colors faithfully and efficiently. For signal processing, MPC systems have a big advantage in the so‐called color‐reproduction redundancy. A number of applications can be derived from this characteristic, such as improving the viewing‐angle dependency issue and power savings. On the other hand, MPC systems have a typical trade‐off versus RGB‐standardized input signals, especially for reproducing bright green. New algorithms to moderate this trade‐off on MPC systems by employing color‐reproduction redundancy are proposed. The goal of our algorithms is to maintain the compatibility with RGB‐based input signals though the initial display design so that the characteristics of MPC systems are not changed or lost. These algorithms indicate that MPC display systems are applicable not only for a specifically limited objective but also for other applications, e.g., TV broadcasting.     

Liquid-Phase Oxidation of Benzene to Phenol by Molecular Oxygen over La Catalysts Supported on HZSM-5

The liquid-phase oxidation of benzene to phenol over lanthanum oxide catalysts (LaOx/HZSM-5) supported on HZSM-5 was studied in the presences of oxygen as an oxidant and ascorbic acid as a reducing regent. LaO_x/HZSM-5 effectively catalyzes the formation of phenol at 353 K under the pressurization of oxygen. The LaO_x/HZSM-5 catalysts take place no leaching of lanthanum species from the catalysts to acidic solvent. Therefore, it is demonstrated that the supported lanthanum catalysts are stable and reusable for the benzene oxidation even in the acidic reaction solution.     

Protein Adsorption on Hydroxyapatite Nanosensors with Different Crystal Sizes Studied In Situ by a Quartz Crystal Microbalance with the Dissipation Method

Hydroxyapatite (HAp) nanocrystals with different crystal sizes were deposited by the electrophoretic deposition method on the gold surface of a quartz crystal microbalance with a dissipation probe. The nanosensors formed this way were used to elucidate the adsorption mechanism of proteins with a similar pI value. The crystal sizes and the area of the a -plane affected only the adsorption amount of human serum albumin, but not that of bovine plasma fibrinogen. The viscoelastic property, Δ D/ Δ f , of each absorbed layer on the nanosensors was almost constant. The protein adsorption mechanism can be explained as follows: the dissociated carboxyl groups (negative charge) of albumin were interacted with calcium ions and the hydrated amine groups (positive charge) at the αC domain of fibrinogen were with phosphate ions on the HAp surface.     

A REACTION-EXTRACTION-REGENERATION SYSTEM FOR HIGHLY SELECTIVE OXIDATION OF BENZENE TO PHENOL

The reaction-extraction-regeneration system for the liquid-phase oxidation of benzene to phenol in the benzene-water-oxygen system was investigated. Phenol was extracted in the extractor to reduce the concentration of phenol in the benzene phase. As vanadium catalyst was oxidized to inactive species after the oxidation reaction, the regenerator was installed in the system to reduce the oxidation state of vanadium catalyst from V⁴⁺ or VO²⁺ to the active V³⁺ under H₂ flow. The effects of various operating parameters including concentration of VCl₃ catalyst, O₂ and H₂ flow rates, benzene bubble size, pH, surface area of Pt regeneration catalyst, the metal species, and amount of ascorbic acid were investigated. Ascorbic acid was employed as a reducing agent for helping reduce the V⁴⁺ form to the active form and therefore improving the activity of vanadium catalyst. VCl₃ catalyst concentration of 10 mol/m³ with pH of 3–4 in the reactor and Pt surface area of 0.05 m² in the regenerator showed optimal conditions for the system.     

Burning of MOX fuels in LWRs; fuel history effects on thermal properties of hull and end piece wastes and the repository performance

The thermal impacts of hull and end piece wastes from the reprocessing of MOX spent fuels burned in LWRs on repository performance were investigated. The heat generation rates in MOX spent fuels and the resulting heat generation rates in hull and end piece wastes change depending on the history of MOX fuels. This history includes the burn-up of UO₂ spent fuels from which the Pu is obtained, the cooling period before reprocessing, the storage period of fresh MOX fuels before being loaded into an LWR, as well as the burn-up of the MOX fuels. The heat generation rates in hull and end piece wastes from the reprocessing of MOX spent fuels with any of those histories are significantly larger than those from UO₂ spent fuels with burn-ups of 45 GWd/THM. If a temperature below 80°C is specified for cement-based materials used in waste packages after disposal, the allowable number of canisters containing compacted hull and end pieces in a package for 45 and 70 GWd-MOX needs to be limited to a value of 0.4–1.6, which is significantly lower than 4.0 for 45 GWd-UO₂.     

Thermoelastic analyses of cladding on beam transient of lead–bismuth cooled accelerator-driven system

The thermoelastic analyses of cladding for lead–bismuth cooled accelerator-driven system (ADS) are conducted for the beam transients. The beam transients are considered to be caused by the abnormal behavior of the accelerator and are peculiar to ADS. The program of the thermoelastic analyses is developed for the evaluation of the stresses of the cladding. This program is intended to analyze a fuel pin of a cylindrical model, and solves the thermoelastic problem by the use of the finite-element-method. The beam transients are analyzed by employing the ADS dynamic calculation code and the program of the thermoelastic analyses for the ADS designed by Japan Atomic Energy Agency. As a result, the transformation of the beam shape does not cause the cladding failure. However, the ductile failure is caused by the beam incident position change in several seconds. These results are also compared with those of the creep analyses conducted in the previous study, and both the creep and the ductile failure are revealed to be caused by the beam incident position change. Consequently, the beam incident position change is concluded to have a high risk of cladding failure.