Studies on the behaviour of microorganisms in sponge cake during anaerobic storage (studies on protection against microbiological deterioration of packaged food part xx iv)

The protective effect of an oxygen absorber (commercial names: Vitalon LH-250, Vitalon GSA-250, produced by Toa Kasei Industrial Co.) and an alcohol generating agent (commercial names: Antimold 102, Antimold E, produced by Froint Sangyo Co.) on the growth of microorganisms in sponge cake stored at 25 °C for 120 days was investigated. In the testing of the oxygen absorbers (oxygen-free) and the alcohol generating agents (alcohol), each sponge cake was inoculated with 3.1 × 10¹⁰ cells of the yeast Hansenula anomola IFO 1760 and was preserved in an air-tight bag (KET) with the oxygen absorbers and/or alcohol generating agent. The results obtained were as follows. In the case of sponge cake without oxygen absorber or alcohol generating agent, bacteria and yeast (including inoculated yeast) in the sponge cake rapidly increased at 25 °C for 30 days. However, in the oxygen-free and alcohol-generating cases, the changes of bacteria and yeast in the sponge cake were slight. The growth of bacteria and yeast was reduced considerably by the use of carbon dioxide generating oxygen absorbers or alcohol generating oxygen absorbers.     

Influence of AC-DC parallel interconnection on voltage stability of AC systems

The static and dynamic characteristics of power supply to each node in a hybrid ac-dc power system are analyzed by means of static and transient P-V curves. Three kinds of dc transmission control scheme are compared. DC transmission systems are more effective in delivering power to inverter nodes. The constant firing angle, constant current control techinque provides more power to inverter nodes than the conventional constant current, constant voltage and constant power, constant extinction angle techniques. Transient digital simulations indicate that dc interconnection improves voltage stability to both the opening of a dc interconnected line and one-line opening of ac double-circuit interconnected lines.     

Preparation of amphoteric latex by modification of styrene–acrylamide copolymer latex

Styrene–acrylamide copolymer latex prepared from the polymerization in an emulsifier-free aqueous medium was treated with hypochlorite and sodium hydroxide. The resulting latex indicated amphoteric property due to amino and carboxyl groups formed by the Hofmann reaction and competitive hydrolysis of amide groups, respectively. Amphoteric latices with the same particle size but different charge density (1.0–3.0 ionic groups/100 Ų) and different isoelectric points (6.4–9.2) have been prepared by changing the reaction conditions.     

Visible dichroism of the poly(ethylene terephthalate)–disperse dye system at high temperatures

The dichroic behavior of PET film dyed at 70°C with Disperse Red 17 or Disperse Yellow 7 was investigated in the temperature range 20–200°C with a view to studying the changes in amorphous region of PET at high temperatures. The dichroic orientation factor D versus temperature plot is expressed by a straight line with negative slope; two breaks appear at 80 (T_g) and 120°C. So long as the amorphous structure does not change irreversibly, the values of D change reversibly with the temperature. Hence, if a change in D after heating is observed at room temperature, it is evidence that an irreversible change occurred in the amorphous structure during the heating. The break at 120°C is a new amorphous transition point of PET existing along with T_g, although the T_g can hardly be observed after the cold crystallization; some phenomena reported in the literature are proposed as evidence.     

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.