The measurement of hydrogen activities in molten copper using an oxide protonic conductor

We have developed a hydrogen sensor for in situ measurements of hydrogen activities in molten copper. The sensor consists of a concentration cell utilizing a proton conductor, CaZr_0.9In_0.1O_3-δ, as the solid electrolyte. The electromotive force (emf) of the cell was generated by both hydrogen and oxygen activity gradients across the cell in a high-temperature region simulating the fire refining processes of copper. However, accurate hydrogen activity in molten copper could be evaluated from the emf if oxygen activity in molten copper was determined simultaneously by another concentration cell and if the hydrogen and the oxygen activities at the reference electrode were known. The performance of the sensor was studied under various conditions. The observed good response and reliability of the sensor show that it should be a powerful tool for improvement of the fire refining process of the molten copper. Theoretical treatment of the calculation of the emf of the concentration cells using a mixed ionic conductor, i.e., protonic and oxide ionic conductor, as solid electrolytes is also discussed briefly.     

Formation of high-purity organic thin films by gas flow deposition and the effect of impurities on device characteristics

A gas flow deposition (GFD) system was developed to manufacture large-scale organic light-emitting diodes (OLEDs). A N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine (α-NPD) thin film with a high purity of 99.97% was obtained using the GFD system. The film properties such as morphology, and electrical and optical characteristics were almost the same as those of films made by conventional vacuum thermal evaporation.     

Preparation of novel porous solids from alumina-pillared fluorine micas by acid-treatment

New porous solids from alumina-pillared fluorine micas (APMs), which were obtained from synthetic Na-tetrasilicic fluorine mica [NaMg_2.5Si₄O₁₀F₂], were prepared by sulfuric acid-treatment under mild conditions at 25 °C. The products were investigated by XRD, ICP, SEM, TEM and N₂ adsorption–desorption isotherm at 77 K. XRD measurements indicated that the interlayer pillared structure having a large basal spacing collapsed during the early stages of the acid-treatment. ICP analyses indicated that Al³⁺ and Mg²⁺ ions were leached out from the pillared micas during the acid-treatment. The pore properties of the leached products were found to differ from those of the mother pillared micas: the acid leaching of the pillared micas leads to the formation of mesopores around 3.2 nm in diameter. The correlation between the change in pore properties and cation elution behavior suggests that the mesopore formation results from the leaching of Mg²⁺ ions from the octahedral sheet of the pillared micas. The leached products thus obtained retained the flaky morphology of the mother pillared micas. These results show that the mild acid-treatment using APMs provides a novel route for obtaining unique mesopore solids having the large particle sizes of the mother micas.     

Correlation of temperature rise and velocity along an inclined fire plume axis in crosswinds

Experiments with a single fire source were carried out in crosswinds in order to elucidate the correlation between temperature rise and velocity along an inclined fire plume axis. A circular propane burner with a diameter of 0.2 m was used as a model fire source. The temperature and velocity were measured along the inclined fire plume axis, and these were compared with fire plume data obtained in a calm condition. An empirical formula to represent the correlation of the temperature rise and velocity was developed. The values of empirical coefficients and exponents were derived from the experimental results of the circular burner. In order to verify the availability of the proposed empirical formula, the comparison was carried out with the data obtained from square and/or rectangular burners.     

Uptake and utilization of ectoine by halotolerant Brevibacterium sp. JCM 6894 subjected to osmotic downshock

The concentration changes of the cyclic amino acid ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyridine carboxylic acid) in Brevibacterium sp. JCM 6894 cells subjected to an osmotic downshock were investigated. When the cells grown in the presence of 2 M NaCl were suspended in deionized water, they immediately released about 60% of the ectoine synthesized intracellularly. During the subsequent incubation, we observed that both the extra- and intracellular concentrations of ectoine were reduced almost linearly with the incubation time. When ectoine was provided externally to the downshocked cells, a similar reduction in both intra- and extracellular ectoine concentrations was recognized. In addition, we observed an increase in ectoine accumulation at about 10 h of incubation, which indicates that ectoine was taken up by such downshocked cells in the absence of external Na+. Furthermore, the downshocked cells showed higher levels of survival, respiration, and growth in the presence of ectoine than in its absence. The ability to take ectoine up was induced in the cells grown in the presence of >0.25 M NaCl for >12 h. Thus, we conclude that even under the lower osmotic condition ectoine might be taken up and subsequently utilized by strain JCM 6894 subjected to the osmotic downshock, indicating that the uptake of ectoine by such cells occurred for the survival and growth of the cell itself rather than for cellular osmoregulation.     

Field instrument for simultaneous large dynamic range measurement of atmospheric hydrogen sulfide, methanethiol, and sulfur dioxide

We describe a membrane-based collection/analysis system that differentially monitors H2S and CH3SH, and to which a conductometric SO2 analyzer using the same collector was coupled. A diffusion scrubber (DS) comprised of a Nafion tube collects H2S selectively while a porous polytetrafluoroethylene (pPTFE) DS collects both H2S and CH3SH. Both gases are measured via their ability to react with fluorescein mercuric acetate (FMA) which results in decreased fluorescence. The limited dynamic range of a negative signal procedure was overcome by using dual DS units comprised of short and long scrubbers, placed serially in the liquid flow line. Different DS designs and membrane materials were investigated. H2S, CH3SH, and SO2 from a biogenic point source were continuously measured, and the H2S/CH3SH data compared well with a standard procedure involving Tedlar bag collection, preconcentration and thermal desorption from a Tenax trap, and measurement by gas chromatography/flame photometric detection. Walkaround portability of the instrument and very large dynamic range measurement of H2S and SO2 were demonstrated around the Mt. Aso volcano.     

Hydrothermal Synthesis of Oriented Anatase Films Consisting of Columnar Aggregates and Their Wetting Properties

We hydrothermally synthesized anatase films on Ti substrates from transparent aqueous solutions of layered titanate colloids. The morphology and wetting properties of the films were examined. The films consisted of columnar aggregates grown on the Ti substrates, which resulted in high orientation. Randomly oriented films were obtained when alumina was used as a substrate, whereas the sol–gel precoating of a titanium oxide (TiO₂) layer on alumina substrates resulted in similar orientation as that of the films on Ti substrates. Thus, the presence of TiO₂ on the substrate surface plays an important role in the orientation of columnar aggregates. The columnar aggregates were similar in microstructure to the arms of a type of six-pointed star-like anatase aggregate synthesized hydrothermally from the same reaction solutions. They were composed of twins of tapered anatase nanocrystals, which provided a rough film surface. The film surface was highly hydrophilic and oleophilic due to the nanoscale roughness even when the film was not irradiated with UV light.     

Classification of particles by centrifugal separator and analysis of the fluid behavior

This study gives fundamental knowledge on the particle classification performance by centrifugal separator.It is found that the cut size of a centrifugal separator decreases as the rotational speed increases and the liquid flow rate decreases. Fitting our experimental results with the theory, they agree with each other at high flow rate. However, the difference between them generates at low flow rate. This is because dead spaces are generated in the centrifugal separator at the low flow rate. Also, the computer simulation of the fluid behavior in the centrifugal separator can find the decrease of the velocity near the wall under the low flow rate, which suggests the possibility of the formation of dead spaces in the separator.     

Competitive adsorption of fibronectin and albumin on hydroxyapatite nanocrystals

Competitive adsorption of two-component solutions containing fibronectin (Fn) and albumin (Ab) on hydroxyapatite (HAp) nanocrystals was analyzed in situ using the quartz crystal microbalance with dissipation (QCM-D) technique. Adsorption of the one-component protein (Fn or Ab) and the two-component proteins adjusted to different molar ratios of Fn to Ab at a fixed Fn concentration was investigated. The frequency shift (Δf; Hz) and the dissipation energy shift (ΔD) were measured with the QCM-D technique, and the viscoelastic changes of adlayers were evaluated by the saturated ΔD/Δf value and the Voigt-based viscoelastic model. For the adsorption of the one-component protein, the Fn adlayer showed a larger mass and higher viscoelasticity than the Ab adlayer, indicating the higher affinity of Fn on HAp. For the adsorption of the two-component proteins, the viscoelastic properties of the adlayers became elastic with increase in Ab concentration, whereas the adsorption mass was similar to that of Fn in the one-component solution regardless of the Ab concentration. The specific binding mass of the Ab antibody to the adlayers increased with increase in Ab concentration, whereas that of the Fn antibody decreased. Therefore, Fn preferentially adsorbs on HAp and Ab subsequently interacts with the adlayers, indicating that the interfacial viscoelasticity of the adlayers was dominated by the interaction between Fn and Ab.     

Isolation, inoculation to insect host, and molecular phylogeny of an entomogenous fungus Paecilomyces tenuipes

BACKGROUND: To improve the poor prognosis of patients with advanced incurable gastric cancer, intensive chemotherapy combined with radical surgery was used. PATIENTS AND METHODS: Thirty patients with incurable gastric cancer were treated with a combination of 5-fluorouracil (370 mg/m2) and leucovorin (30 mg/person), given intravenously for five consecutive days, followed by cisplatinum (70 mg/m2) and etoposide (70 mg/m2) on days 6 and 20, delivered through a catheter placed either in the aorta with its tip at the level of the ninth thoracic vertebra or in the celiac artery. This treatment (FLEP therapy) was repeated twice every 5 weeks. Radical or palliative surgery followed chemotherapy. RESULTS: The overall response rate to the chemotherapy was 50.0% (15 of 30 patients, 95% confidence limit 0.305-0.671). Nineteen patients (15 with a partial response, three showing no change, and one with progressive disease) underwent surgery. Of these, nine underwent curative surgery and 10 palliative surgery. The median survival time was 6.5 months overall, 12.7 months for responders, and 4.7 months for nonresponders. Long-term survivors were exclusively found among patients with distant lymph node metastasis treated by curative surgery (55.6% at 5 years). CONCLUSIONS: Favorable results of this small phase II study justify a phase III trial.