Purification and properties of an extracellular inulinase from Rhizopus sp. strain TN-96

A filamentous fungus, Rhizopus sp. strain TN-96, was isolated from rhizosphere soil samples. An extracellular inulinase was purified from the culture filtrate of strain TN-96 grown on inulin by DEAE-Cellulofine A-500 and Sephacryl S-200 HP chromatographies. The enzyme was homogeneous as judged by SDS-polyacrylamide gel electrophoresis, with an apparent M(r) of 83 kDa. The purified enzyme had specific activities of 17 U/mg toward inulin (I) and 0.32 U/mg toward sucrose (S) (I/S ratio, 53). Inulinase activity was optimal at pH 5.5 and 40 degrees C. The inulinase exhibited an apparent K(m) value of 9.0 mM for inulin. The enzyme also hydrolyzed raffinose, but not bacterial levan.     

An absorption-based surface plasmon resonance sensor applied to sodium ion sensing based on an ion-selective optode membrane

A surface plasmon resonance (SPR) sodium ion sensor using an ion optode membrane film was experimentally and theoretically described based on an absorption-based SPR principle proposed in our previous article (Kurihara, K; Suzuki, K. AnaL Chem. 2002, 74, 696-701). The sodium ion concentrations from 10(-6) to 10(-1) have been successfully determined not only by the resonance angle diagnosis of the SPR curve but also by the minimum reflectance one. The ion optode film was plasticized poly(vinyl chloride) including a neutral sodium ionophore, a pH-sensitive cationic dye, and an anionic additive. Its optical absorption intensity changed with the sodium ion concentrations. The SPR ion sensor physically measured the complex refractive index caused by the absorption in the ion optode film. We have exhaustively investigated the experimental response behavior of the SPR curve relative to the sodium ion concentrations by comparison with numerically simulated SPR curves using a three-layer Fresnel equation including experimental values for the sodium ion optode membrane film. As predicted by the absorption-based SPR principle, the SPR curve behavior of the SPR ion sensors depended on two factors: one was the relation between the excitation frequency of the light source and the absorption maximum frequency in the ion optode film while the other was the gold metallic thickness in the Kretchmann configuration. The concept and practical theory of an absorption-based SPR sensor not only have been proved by the experimental results of the SPR sodium ion sensor but also have successfully allowed flexible ion sensing in an SPR sensor, which would be very difficult without the absorption mechanism in the ion optode film.     

Estimation of Zn and Cu unit output loads from animal husbandry facilities

Zinc (Zn) and copper (Cu) are toxic to aquatic organisms at very low concentrations that do not affect humans. We measured the daily output of Zn and Cu in wastewater from livestock farms to aquatic environments because waste from animal husbandry operations contains high levels of Zn and Cu. At most pig farms in Japan, a mixture of urine, some faeces, and service water is treated in onsite wastewater treatment facilities and discharged into a water body. Some dairy farms also have wastewater treatment facilities. We surveyed 21 pig farms and six dairy farms. The unit (i.e., per head) output load from piggery wastewater treatment facilities ranged from 0.13 to 17.8 mg/head/d for Zn and from 0.15 to 9.4 mg/head/d for Cu. Over 70% of pig farms had unit output loads of Zn and Cu below 6 and 2 mg/head/d, respectively. For dairy farms, the unit output load from wastewater treatment facilities was estimated at 1.8-3.6 mg/head/d for Zn and 0.6 mg/head/d for Cu. The unit output load for Zn from piggery wastewater treatment facilities was similar to that from treatment facilities for human waste. However, pig farms generally raise several thousand to tens of thousands of pigs; pig farms are therefore presumed to be a significant point source of Zn in rural areas.     

Use of ensemble simulations to evaluate the urban effect on a localized heavy rainfall event in Tokyo,Japan

Recently, localized heavy rainfall over highly urbanized areas has caused severe damage in Japan. Although studies have indicated that the presence of urban areas can intensify rainfall, the chaotic noise caused by differences in initial conditions can change the urban effect. Therefore, the usability of ensemble simulation methods for urban effects on a single localized heavy rainfall event must be clarified to synthesize state-of-the-art observations and numerical model studies. This study examined the difference in a localized heavy rainfall event under different initial conditions. We demonstrated the advantage of ensemble experiments using a cloud-resolving model to evaluate the urban effect. In this study, we focused on a localized heavy rainfall event that occurred over Tokyo on 5 August 2008 and killed five people working in a drainpipe. Two ensemble experiments were performed according to the lagged average forecasting (LAF) method. Each experiment had six members, with initial conditions spanning 6 h from 02 to 07 Local Standard Time (LST) on 5 August 2008. The model was integrated continuously through 18 LST for each run. The model had a horizontal grid resolution of 2 km. The first experiment (CTRL) used the actual land cover, anthropogenic heat, and geometric structures. The second experiment (PDDY) used an imaginary land cover in which the urban area was changed to paddy fields. Comparison of the ensemble means showed that the peak value of the maximum hourly rainfall decreased and the peak time was delayed in PDDY compared with CTRL. The smaller peak value and delayed peak time of rainfall in PDDY seemed to be caused by the weaker updraft associated with near-surface convergence, which was caused by weaker surface heating. Regardless of the difference caused by the initial conditions, the decrease in the peak value and the delay in the peak time were significant according to the t-test. Although the area was limited compared with near-surface temperature and horizontal wind convergence, a significant reduction in rainfall was also seen over the heavily urbanized area of Tokyo in the horizontal distribution of the difference in accumulated rainfall. These results indicate that although differences in the initial condition can change the modeled urban effect on rainfall, ensemble simulation methods can be used to examine the significance of the urban effect on a single localized heavy rainfall event.     

Synthesis and properties of lithium ion conductors Li3−2x(Sc1−xZrx)2(PO4)3

Lithium ion conductors, Li_3−2x(Sc_1−xZr_x)₂(PO₄)₃ (0 x 0.3), were prepared by a solid-state reaction. TG–DTA analysis indicated no phase transition in the samples with x superior to 0.05. X-ray powder diffraction analysis of these samples clearly showed the stabilization of a superionic conduction phase at room temperature with an orthorhombic system Pbcn. The highest conductivity was observed for the sample with x=0.05, and ascribed to the stabilization of the superionic conduction phase and the introduction of vacancies on the Li⁺ sites by substituting Zr⁴⁺ for Sc³.     

UV curable pressure‐sensitive adhesives for fabricating semiconductors. I. Development of easily peelable dicing tapes

In order to develop easily peelable dicing tapes from diced wafers, UV curing of various pressure‐sensitive adhesives (PSAs) was studied. After UV irradiation, the adhesive strength of a PSA composition including a diacrylourethane oligomer (UDA) decreased drastically compared with other compositions. Because of network formation via UV irradiation, this composition had a greater volume contraction that might yield microvoids at the interface between the adhesive and the wafer, resulting in the loose adhesion. Its storage modulus increased up to about 1000 times that before UV curing, which was due to the crosslinking of the UDA component. It was suggested that the increased crosslinking density and the high internal coagulant energy of the UDA backbone structure caused a remarkable decrease of the adhesive strength. Furthermore, it was ascertained that the UV‐irradiated UDA adhesives left few residual deposits on the wafer released from the tape. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 436–441, 2003     

Photo-control of the electronic states of Iron coordinated to photo-responsive polyaniline

Fe³⁺ doped polyaniline (PANI) films containing azobenzene derivatives in the side chain have been prepared. Photoisomerization of the azobenzene derivative in the PANI films was observed at room temperature. Furthermore, ⁵⁷Fe Mössbauer measurements showed that the ligand-metal bond distance and the symmetry around the Fe³⁺ were influenced by the photoisomerization.     

Microstructure and Magnetic Properties of (Co-Fe)-Al-O Thin Films

(Co-Fe)-Al-O soft magnetic thin films were fabricated by cosputtering Co-Fe alloy and Al₂O₃ ceramic targets using an inductively coupled RF (radio frequency) sputtering system. The microstructure and magnetic properties of various (Co-Fe)/(Al-O) thin-film compositions were systematically characterized. A specimen with the composition (Co₇₂Fe₁₇Al₁₁)-O exhibited excellent high-frequency magnetic properties, with a value >300 for the real part of the permeability and >2 GHz for the self-resonant frequency. High-resolution transmission electron images revealed nanometer-order Al₂O₃ amorphous phases separating the Co-Fe alloy nanograins. The excellent high-frequency magnetic properties were derived from the particular microstructure of these thin films.