Orientation factor of polypropylene film by infrared dischroism

The orientation factor by infrared dichroism of polypropylene film was compared with the other orientation factors. After the correction of imperfect polarization and the suitable choice of the base line, it was found that infrared dichroism is a reliable indicator of the orientation factor. Orientation factors obtained from the 998 and 842 cm.^?1 bands agreed with the x-ray orientation factor, and that from the 975 cm.^?1 band agreed with the optical orientation factor.     

Immobilization of α-amylase on polymeric carriers having different structures

α-Amylase was immobilized onto several polymeric carriers having carboxyl groups by the Woodward's reagent K better than by other methods. The amount of immobilized α-amylase mainly depended on the surface area of carriers, while the enzymic activity depended on the texture of carrier surface. Flat surface was favorable for making the enzyme exhibit high activity and for keeping it active in wide pH range. The durability of immobilized enzyme was excellent at 20°C and pH 5.5.     

Detection of Immunomodulating Activities in an Extract of Japanese Edible Seaweed,Laminaria japonica (Makonbu)

A significant immunomodulating activity was found in the hot-water-soluble extract of the most popular edible seaweed in Japan, Laminaria japonica (Makonbu in Japanese) which showed an enhancing activity for DNA synthesis of spleen cells from endotoxin-nonresponder, C3H/HeJ mice. This activity was divided into polysaccharide and non-polysaccharide fractions and the former fraction exhibited much higher activity than that of the latter fraction. The polysaccharide fraction caused stimulatory effects on the ingestive activity of mouse phagocytic cells against Staphylococcus aureus and the release of cytokines, interleukin-1α and tumour necrosis factor α from the same cells. Furthermore, the polysaccharide fraction exhibited enhancing effects on polyclonal antibody (IgM and IgG) production in spleen cells. These immunomodulating activities were associated with polysaccharides themselves, but not contaminating endotoxins in the fraction judged by comparative experiments. The significance of this finding is discussed from the viewpoint of the immunopotentiation by edible seaweeds in host animals.     

Analytical methods for determining a system configuration acceptable from viewpoints of both short circuit current and voltage stability

Generally, improving voltage stability to power demand increase tends to increase short circuit capacity. In this paper, two methods are proposed in order to obtain appropriate system separation points that minimize short circuit capacity increase and voltage stability decrease. Considering the Q-ϵ network that expresses the relation of voltage and reactive power, voltage sensitivity is equivalent to an element of the system impedance matrix. A fast calculation procedure for the change of the impedance matrix element due to bus connection changes has been proposed. It can be applied to the calculation of both the voltage sensitivities and the short circuit capacity. The results give information on the most appropriate separation points among the designated candidates, taking account of short circuit capacity problems and voltage stability considerations. The second method proposed uses a linear programming technique with variable line impedances and the objective function minimizing the short circuit capacity subject to bus voltage dip constraints. This gives information on the preferable separation points in large and complicated systems. Some practical procedures are also given. © 1998 Scripta Technica, Electr Eng Jpn, 124(3): 30–39, 1998     

Radiolysis of Diisodecyl Phosphoric Acid and its Effect on the Extraction of Neptunium

Radiolysis of diisodecyl phosphoric acid (DIDPA) in n-dodecane containing tributyl phosphate (TBP) was examined by analyzing concentrations of acidic extractants and H₃PO₄, and its effect on the extraction of neptunium was studied from the aspect of the extraction rate. For the solvent containing 0.5 M DIDPA and 0.1 M TBP irradiated in the absence of HNO₃, G-values for degradation of DIDPA and for production of dibutyl phosphoric acid (DBP) were found to be 0.47 and 0.14, respectively. For the solvent irradiated in stationary contact with 0.5 M HNO₃, G-value for DIDPA degradation was found to be 0.73, which was 1.7 times larger than the value for the solvent irradiated in the absence of HNO₃.

In the experiment on the extraction of neptunium initially in the pentavalent state from the solution containing 0.5 M HNO₃ and 0.5 M H₂O₂, it was found that the extraction rete tas determined by the concentration of MIDPA forted by radiolysis when the solvent was irradiated with lower dose than 1 MGy in the absence of HNO₃. When the solvent absorbed higher dose or was irradiated in the presence of HNO₃, the extraction rate was influenced by the other radiolysis products. Even in this case, when the solvent contained TBP, the rate varied little until absorbed dose increased over 0.5 MGy.     

Creating a Saccharomyces cerevisiae haploid strain having 21 chromosomes

Chromosome engineering techniques that can manipulate a large segment of chromosomal DNA are useful not only for studying the organization of eukaryotic genomes but also for the improvement of industrially important strains. Toward the development of techniques that can efficiently manipulate a large segment of chromosome, we have previously reported a one-step chromosome splitting technique in a haploid Saccharomyces cerevisiae cell, with which we could successfully split yeast chromosome 11, XIII, or XI into two halves to create a haploid strain having 17 chromosomes. We have now constructed chromosome splitting vectors bearing ADE2, HIS3, LEU2, or TRP1 marker, and by using these vectors, we could successively split yeast chromosomes to create a novel yeast haploid strain having up to 21 chromosomes. The specific growth rates of yeast strains carrying more than 16 chromosomes up to 21 did not differ significantly, suggesting that yeast cells can harbor more chromosomes than they do in their natural state, that is, 16 chromosomes, without serious effects on their growth.     

Precise determination of precipitation yield of uranyl nitrate with N-alkylated 2-pyrrolidone derivatives

Yields of precipitated UO₂(NO₃)₂(NRP)₂ (NRP = N-alkylated 2-pyrrolidone) were precisely determined by considering reduction of the solution volume through the precipitation, which can be estimated from difference in acid concentrations of the liquid phases before and after the precipitation. The studied NRPs were N-n-butyl (NBP) and N-n-propyl (NProP) derivatives. In both systems, the precipitation yields precisely determined were always higher than those simply calculated from the ratio of uranium concentrations before and after the precipitation. However, the differences between them are in the range of 0.6%–2.6%. If such a difference is practically negligible, the volume reduction through the precipitation does not have to be taken into account for simplicity of the analytical manipulation.     

Supposed existence of Np4+ in a genuine dissolver solution from the results of extraction simulation by PARC-L code

With a genuine spent fuel solution (a dissolver solution), a laboratory-scale reprocessing experiment of an extraction–separation process was performed using mixer-settlers as extractors. In the experiment, n-butyraldehyde was utilized as a reducing reagent of Np^(VI)O₂²⁺ to Np^(V)O₂⁺ for the purpose to distinguish Np^(VI)O₂²⁺ from Np⁴⁺. From the Np concentration in the aqueous phase, Np would be extracted from the dissolver solution together with U and Pu. The scrutiny of Np behavior was performed utilizing 66 cases of calculation results by a Japan Atomic Energy Agency open extraction simulation code, the Program for Advanced Extraction with Radiation Effect Calculation–Lightened version. From the scrutiny, the authors found that the calculation result with 60% of Np⁴⁺ in the dissolver solution represented the best experimental extraction–separation behavior of Np. Therefore, it was supposed that the dissolver solution contained sufficient proportion of Np⁴⁺ to affect the extraction–separation behavior of Np.