Phase Stability of the A2Cu3O4X2 (A = Alkaline-Earth; X = Halogen) System

Stability of A ₂ Cu ₃ O ₄ X ₂ (A = Sr, Ba; X =Cl, Br) of the 2342 phase with the Cu ₃ O ₄ plane, which is composed of the Cu(1)O ₂ and extra Cu(2) sublattices, has been studied in the temperature range between 600 °C and 950 °C. Polycrystalline samples of the composition Sr _2–x Ba _x Cu ₃ O ₄ Cl _2–y Br _y were prepared by the solid-state reaction method. From the powder x-ray diffraction analysis, we have made the phase diagram (x vs. y vs. heat-treatment-temperature). It has been found that the 2342 phase becomes stable with increasing x and y at high heat-treatment-temperatures instead of a mixture of CuO and the A ₂ CuO ₂ X ₂ (2122) phase with the CuO ₂ plane. These results can be explained in terms of the structural matching between the Cu ₃ O ₄ plane and the A ₂ X ₂ layer.     

Using promoter replacement and selection for loss of heterozygosity to generate an industrially applicable sake yeast strain that homozygously overproduces isoamyl acetate

By application of the high-efficiency loss of heterozygosity (HELOH) method for disrupting genes in diploid sake yeast (Kotaka et al., Appl. Microbiol. Biotechnol., 82, 387–395 (2009)), we constructed, from a heterozygous integrant, a homozygous diploid that overexpresses the alcohol acetyltransferase gene ATF2 from the SED1 promoter, without the need for sporulation and mating. Under the conditions of sake brewing, the homozygous integrant produced 1.4 times more isoamyl acetate than the parental, heterozygous strain. Furthermore, the homozygous integrant was more genetically stable than the heterozygous recombinant. Thus, the HELOH method can produce homozygous, recombinant sake yeast that is ready to be grown on an industrial scale using the well-established procedures of sake brewing. The HELOH method, therefore, facilitates genetic modification of this rarely sporulating diploid yeast strain while maintaining those characteristics required for industrial applications.     

Study on the chimney effect in natural air‐cooled electronic equipment casings under inclination: Proposal of a thermal design correlation that includes the porosity coefficient of an outlet opening

Natural air‐cooling technologies for electronic equipment have the important advantages of no fan and high reliability. However, natural air cooling has lower cooling capability than fan air cooling, so enhancement of its cooling capability is required. This paper presents the results for experimental casings designed to employ the chimney effect in natural air‐cooled electronic equipment. The system casing is inclined to enhance the effectiveness of natural air cooling. Experiments were carried out using a thin laptop PC. We investigated the effect on cooling capability produced by inclining the casing and by varying the outlet positions and numbers and the porosity coefficient of the outlet openings. The results show that the temperatures inside the casing and heater surfaces are slightly diminished by the effect of increased inclination and porosity coefficient of outlet openings. Moreover, the increase in natural circulation flux in the casing was quantitatively proven by experiments. In addition, the experimental data were reduced to a Nusselt number–Rayleigh number correlation, , by using a modified reference length. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(2): 122–136, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20103     

Development of a Cherenkov light imaging system for studying the dynamics of radiocesium in plants

High-resolution images of radiocesium (¹³⁷Cs) distribution are required to study cesium kinetics in plants. A Cherenkov light imaging system can visualize fine distributions of radionuclides emitting beta particles using an optical camera. To evaluate the linearity of the system, an imaging test was performed with point sources of ¹³⁷Cs, with a radioactivity of 10–2000 kBq. The results indicated that the system has a good linearity between the image intensity and the radioactivity of ¹³⁷Cs. We developed an imaging system for plants using this system to study radiocesium movement in intact plants. To demonstrate the ability to image radiocesium in a plant, an experiment was performed with an intact soybean plant for four days. The root of an 11-day-old soybean plant was dipped in 20 mL of a culture solution containing ¹³⁷Cs with a radioactivity of 10 MBq without potassium. After one day, the solution was replaced with one with potassium but no ¹³⁷Cs. The soybean plant was in healthy condition in the system, and the high-resolution serial images indicated that ¹³⁷Cs was transported to the shoot and accumulated in the node. Therefore, Cherenkov light imaging is promising for imaging radiocesium in intact plants.     

Optical pump-and-probe test system for thermal characterization of thin metal and phase-change films

A single-shot optical pump-and-probe test system is reported. The system is designed for thermal characterization of thin-film samples that can change their phase state under the influence of a short and intense laser pulse on a subnanosecond time scale. In combination with numerical analysis, the system can be used to estimate thermal constants of thin films, such as specific heat and thermal conductivity. In-plane and out-of plane thermal conductivity can be estimated independently. The system is intended for use in research on optical data storage and material processing with pulsed laser light. The system design issues are discussed. As application examples, we report on using the system to study thermal dynamics in two different thin-film samples: a gold film on a glass substrate (a single-phase system) and the quadrilayer phase-change stack typical in optical data-storage applications.     

Oligonucleotide bearing ethylenediamine-N,N,N'-Triacetates for gap-selective DNA hydrolysis by Ce4+/EDTA

With the use of two oligonucleotides bearing ethylenediamine-N,N,N'-triacetate groups as additives, gap sites were formed at predetermined sites in substrate DNA. Upon treating these systems with a Ce(4+)/EDTA complex at pH 7.0 and 37 degrees C, the phosphodiester linkages at the gap site were selectively hydrolyzed. The DNA scission was greatly promoted by the introduction of ethylenediaminetriacetate groups, and the scission efficiency increased as the number of these groups increased. Even a one-base gap was successfully hydrolyzed when three ethylenediaminetriacetate groups were placed consecutively at both edges of the gap, although the scission was minimal in the absence of these groups. The site-selective scission could be also achieved at higher temperatures without any significant loss of site-selectivity.     

Chemical and Olfactory Characterization of Odorous Compounds and Their Precursors in the Parotoid Gland Secretion of the Green Tree Frog, Litoria caerulea

When stressed or challenged by a predator, the Australian green tree frog, Litoria caerulea, emits a characteristic nutty odor from its parotoid glands. This study identifies the source of the odor as the cyclic amide 2-pyrrolidone (2-PyrO). In addition, we demonstrate the presence of 2-PyrO's straight chain form, -aminobutyric acid or GABA, in the frog's glandular secretion and propose an odorant–precursor relationship. What role both compounds play in the frog's defensive strategy remains unknown. Prolonged exposure to the odor is shown to result in adverse effects that may be attributed to a GABAergic mechanism. It is our hypothesis, however, that the odor acts as an aposematic signal, indicating the toxicity of the frog's nonvolatile secretion.     

Identification of fish species in dried fish products by immunostaining using anti-myosin light chain antiserum

In order to immunologically detect fish species used in boiled and dried fish products (dried fish sticks), the availability of antiserum against myosin light chains was examined. After dissolving the samples in the presence of 8 M urea and 1% sodium dodecyl sulfate (SDS), the solubilized matters were applied to SDS–polyacrylamide gel electrophoresis and electroblotted onto PVDF membranes. Subsequently, protein bands concerned were stained using anti-myosin light chain (alkali light chain 1) rabbit antiserum and horseradish peroxidase-conjugated anti-rabbit immunoglobulin. Most of the fish species could be identified by fingerprinting of immunostained patterns even after drastic processing, even though the protein staining patterns were not clear enough for species identification.     

Recovery of acid from wastewater by electrodialysis

The optimum operating conditions for electrodialysis using a newly developed membrane were studied for recovery of acid from acidic wastewater released from the iron and steel industry. The limiting current densities I_lim/S and the current efficiencies η_I could be expressed by the following equations, respectively.

Furthermore, the concentration of iron(III) ion should be controlled lower than one twentythird of C, since the electric resistance of the cation-exchange membrane was increased considerably by fouling with iron(III) ion.