Preparation, structure, and electrical conductivity of vanadium fluoridegraphite intercalation compound

Graphite intercalation compounds (GIC) of vanadium fluoride have been prepared in a fluorine atmosphere. The GICs prepared from highly oriented pyrolytic graphite (HOPG) were stage 1–8 compounds with composition, C_8.4–79.5VF_5.8–6.0. The apparent size of intercalated VF₆⁻(d_i) decreased from 5.33 Å to 4.15 Å along the c axis with increasing x in C_xVF₆. Various intercalated structures of VF₆⁻ between the carbon layers have been proposed for this change in d_i values. The compounds with small d_i around 4.2 Å show high stability in the air, which is due to the nestling of the VF₆⁻ anion between the carbon layers. Electron diffraction measurements have indicated that a well-nestled stage 2 GIC has high regularity in orientation of intercalated VF₆⁻ anions, which make two large unit cells of the hexagonal system ( ) with the different vectors by ±14° from that of graphite lattice. The ¹⁹F-NMR spectra and X-ray diffraction data in the low temperature region suggest a reversible phase transition. The highest electrical conductivity was 1.97 × 10⁵Scm⁻¹, which is 12 times that of pristine HOPG.     

N-terminal amino acid sequences of troponin T fragments, including 30 kDa one, produced during postmortem aging of bovine longissimus muscle

We have determined the amino (N)-terminal amino acid (AA) sequences of five troponin T (TnT) fragments produced during postmortem aging of bovine longissimus muscle. Western blot analysis showed that 32.1, 28.8, 27, and 25.8 kDa anti-fast-type TnT (fTnT)-positive fragments and a 31 kDa anti-slow-type TnT (sTnT)-positive fragment were present at 14 d postmortem. The N-terminal AA sequences of the 32.1, 28.8 (conventional 30 kDa), 27, and 25.8 kDa fragments were APPPPAEV, EVHEPEEK, EKPRPRLT, and APKIPEGE, respectively, and they were mapped to the N-terminal region of bovine fTnT isoforms. The N-terminal sequences of the 31 kDa fragment, EAPEEPEP, were mapped to the sTnT isoforms. These findings indicate that the two isoform types of fTnT predominantly expressed in the longissimus muscle are cleaved specifically at Glu(21)-Ala(22) and Glu(15)-Ala(16), His(37)-Glu(38) and His(31)-Glu(32), Glu(43)-Glu(44) and Glu(37)-Glu(38), and/or Thr(51)-Ala(52) and Thr(45)-Ala(46), respectively, and that a sTnT isoform is cleaved specifically at Glu(23)-Glu(24).     

Influence of poling conditions on the piezoelectric properties of PZT ceramics

The influence of the poling temperature, the poling electric field, the poling time and the distance between electrodes on the dielectric constant _r and the electro-mechanical coupling factor k_r of PZT were investigated using a statistical analysis method. Interactions between various factors affecting _r and k_r parameters were found particularly, with regard to the poling temperature. The k_r value of PZT is influenced more by the absolute voltage than by the applied electric field strength.     

Membrane process for emulsified waste containing mineral oils and nonionic surfactants (alkylphenolethoxylate)

Using membrane processes we studied the improvement of the treatment of waste emulsified by mineral oils and alkylphenolethoxylate (APE) and investigated diatomaceous earth processing for comparison. A quantitative analysis of the mineral oils and APE using column chromatography was applied to assess these processes. Despite substantial rejection of the turbidity values of emulsified model waste, the percentages of mineral oil and APE rejections using microfiltration (MF) processes were 39-61% and 16-19%, respectively. In contrast, the ultrafiltration (UF) process could reject 97% for the mineral oils and 90% for APE. The diatomaceous earth adsorption processes reduced the mineral oils 40-49% and the APE, 8-14%, and therefore were inferior to the UF process for waste treatment. The average fluxes of both the MF and UF membranes until the volume reduction factor (VRF) reached a value of 5 were almost the same in the range of 8 x 10(-6)-14 x 10(-6) m3 m-2 s-1. For commercial application, decrease in the permeate flux by fouling needs to be resolved.