DISTRIBUTION OF N- AND ISO- BUTYRALDEHYDES BETWEEN TRI-N-BUTYL PHOSPHATE/ N-DODECANE AND NITRIC ACID

ABSTRACT

The distribution of n- and iso-butyraldehydes between tri-n-butyl phosphate(TBP) n-dodecane(nDD) and HNO₃ were measured. The distribution ratio of n-butyraldehyde in the TBP/nDD and HNO₃ system was nearly the same as that of iso-butyraldehyde. The distribution ratios of n- and iso-butyraldehydes increased with TBP concentration in the organic phase. The equilibrium constant of the extraction reaction was about 2. In a uranium, neptunium and plutonium separation process, most of the n- and iso-butyra1dehydes fed into theNp separation stepor into thePu/U partition will be left with the TBP solvent. The two compounds will be partly back-extracted to the aqueous phase in the U purification and in the solvent washing steps of the PUREX process.     

Peel Test Using Nonstationary Peel Method

The cohesive peel spectra of pressure-sensitive adhesive (PSA) tapes have been measured using a non-stationary peel tester. The experimental evidence and a viscoelastic analysis based on a peel model indicate that there are no significant effects of acceleration in the normal rate region. The nonstationary peel tester can be regarded as a useful tool for testing and evaluating PSA tapes.     

Temperature and frequency dependence of dielectric loss of Ba(Mg1/3Ta2/3)O3 microwave ceramics

Ba(Mg_1/3Ta_2/3)O₃ ceramic possessing extremely high Q × f value of more than 300 THz at microwave frequency was developed in our previous study. It is of great interest to understand the mechanism of microwave absorption in such a practical material. In the present study we report on the temperature dependence of the dielectric loss in the Ba(Mg_1/3Ta_2/3)O₃. The mechanism of the microwave absorption is discussed using two phonons difference process. The samples were prepared by conventional solid state reaction and sintered at 1893 K in oxygen atmosphere. Dielectric properties in the microwave range were measured by Hakki & Colemann and resonant cavity methods in the temperature range of 20–300 K. Whispering gallery mode technique was used for the measurement of the dielectric properties at the millimeter wave frequency. Dielectric loss of the Ba(Mg_1/3Ta_2/3)O₃ at the microwave frequency increases with temperature between 200 and 300 K in general agreement with the theory of intrinsic dielectric loss derived from the two phonon difference process. However below 200 K, the dielectric loss has shown a distinctive behavior with a loss peak at 40 K. It was inferred that the loss peak of the Ba(Mg_1/3Ta_2/3)O₃ was caused by the local orientation polarization having dispersion at the microwave frequency.     

Phase structure in the blend of atactic poly(vinyl alcohol) with atactic poly(vinyl alcohol‐block‐vinyl acetate)

An almost fully saponified atactic poly(vinyl alcohol) and an atactic poly(vinyl alcohol‐block‐vinyl acetate) of which degree of saponification is 89 mol % were blended by a solution casting method. The phase structure of the blend film was analyzed by optical microscopy, ¹³C‐NMR, and differential scanning calorimetry. The most remarkable structure of the blend was composed of cylindrical domains penetrating the film. The swelling behavior of the blend films was also investigated in the dimethylsulfoxide and water mixed solvents to find differences in solubility and diffusion behavior between the matrix and the domain. The cylindrical domains could be selectively dissolved away in water and the film became porous. We tried to change the size of the cylindrical domain with various film preparation conditions. This aimed to turn the film into the useful filter membrane. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1807–1815, 2002     

Beneficial effect of carbon–PVA colloid additives for lead–acid batteries

Based on the previous success of adding ultra-fine carbon–PVA (polyvinyl alcohol) colloid solution to restore performance of weak batteries, a large scale test programme of practical batteries including those used in forklift, golf cart, taxi cab, truck and bus applications from 150 companies was carried out. More than 95% of the tested batteries exhibited excellent recovery in performance parameters including the specific gravity (S.G.), voltage and operation time (Ah capacity). The work reported here includes basic research studies to understand better the beneficial action of the carbon–PVA colloid additive.