Characteristics of Multi-Phase Alternating Current Arc for Glass In-Flight Melting

An innovative in-flight melting technology with multi-phase AC arc was developed for glass industry. The enthalpy probe and high speed video camera were used to characterize the temperature, velocity, and discharge behavior of multi-phase AC arc. The effects of input power and sheath gas flow rate on arc and melting behavior were investigated. Results show that the temperature and velocity on arc center are increased with input power or sheath gas flow increase. The fluctuation of luminance area ratio and coefficient of variation reflects the change of arc discharge behavior. High temperature of plasma enhances the melting of granulated raw particles during in-flight heating treatment. The shrinkage of particle and the volatilization degree of Na₂O increase under a larger flow rate of sheath gas. The characterized arc behavior agrees with the melting behavior of glass raw materials, which can provide valuable guidelines for the process control of glass melting.     

Random dispersion approximation for the Hubbard model

We use the Random Dispersion Approximation (RDA) to study the Mott-Hubbard transition in the Hubbard model at half band filling. The RDA becomes exact for the Hubbard model in infinite dimensions. We implement the RDA on finite chains and employ the Lanczos exact diagonalization method in real space to calculate the ground-state energy, the average double occupancy, the charge gap, the momentum distribution, and the quasi-particle weight. We find a satisfactory agreement with perturbative results in the weak- and strong-coupling limits. A straightforward extrapolation of the RDA data for L ≤ 14 lattice results in a continuous Mott-Hubbard transition at U_c≈W. We discuss the significance of a possible signature of a coexistence region between insulating and metallic ground states in the RDA that would correspond to the scenario of a discontinuous Mott-Hubbard transition as found in numerical investigations of the Dynamical Mean-Field Theory for the Hubbard model.     

Antitumor agents. V. Synthesis and antileukemic activity of E-ring-modified (RS)-camptothecin analogues.

Several E-ring-modified analogues of (RS)-camptothecin were synthesized by total synthesis via Friedl?nder condensation and evaluated for cytotoxicity and antitumor activity against P388 mouse leukemia cells. Among them, (RS)-20-deoxyamino-7-ethyl-10-methoxycamptothecin (25c) was found to be more active than (RS)-camptothecin (1) in the in vivo assay.     

AN ACTION SPECTRUM OF PHOTOREACTIVATING ENZYME FROM SEA URCHIN EGGS

An action spectrum for photoreactivating enzyme activity from unfertilized eggs of the sea urchin Hemicentrotus pulcherrimus was determined. The range of the spectrum is 313 to 500 nm, with a maximum at 365 nm. Comparison of this spectrum with that for photorecovery of developmental damage in the sea urchin embryo indicates the general similarity of the two processes.     

The ground states of the classical heisenberg and planar models on the triangular and plane hexagonal lattices

The energies and the spin configurations of the ground states of the classical Heisenberg and classical planar (XY) models with first- and second-neighbor interactions on the triangular and plane hexagonal lattices are obtained. The phase diagrams in theJ ₁–J ₂ plane are determined, whereJ ₁ andJ ₂ are the coefficients of the first- and second-neighbor interactions, respectively. It is noted for the system on the plane hexagonal lattice, that an infinite degeneracy of the ground states occurs in some region of theJ ₁–J ₂ plane and then the study is made under an introduction of an infinitesimal third-neighbor interaction, removing the degeneracy.     

Coisotactic shift contributions in 13C NMR spectra of propylene/butene-1 copolymers

Coisotactic shift contributions caused by sterically crowded isotactic side-chain alkyl groups are proposed for peak assignments of isotactic propylene/butene-1 copolymers. Previously disputed analyses of methine triads and PB tetrads of backbone methylene carbons (α,α′-CH₂) have been verified using first-order Markovian distribution theory. Coisotactic shift contributions also account for the reverse order of the propylene-centered triads from that predicted by the Grant-Paul equation.     

Arginine improves protein elution in hydrophobic interaction chromatography. The cases of human interleukin-6 and activin-A

The effects of arginine on protein binding and elution in hydrophobic interaction chromatography (HIC) were examined using recombinant human interleukin-6 (IL-6) and activin-A. Binding of IL-6 in the presence of ammonium sulfate (AS) was tested using low- and high-substituted phenyl-sepharose. While inclusion of arginine during loading of IL-6 resulted in incomplete binding to the low-substituted phenyl-sepharose, binding was complete to the high-substituted phenyl-sepharose. Arginine facilitated elution of IL-6 from both columns. These results demonstrate that arginine weakens hydrophobic interactions between IL-6 and the phenyl-sepharose. More drastic results were obtained using activin-A, which showed undetectable recovery from phenyl-sepharose. Although no apparent elution of activin-A was observed from butyl-sepharose in aqueous buffer alone, the addition of arginine to the buffer resulted in partial elution recovery and, together with ethanol, resulted in greatly improved recovery of the protein. Two arginine derivatives, acetylarginine and agmatine, were also effective. These results show that arginine improves protein elution in HIC.     

Synthesis and Photocatalytic Properties of TiO2 Intercalated H4Nb6O17

Abstract

TiO₂ intercalated H₄Nb₆O₁₇ has been synthesized by the reactions of H₄Nb₆O₁₇ with a titanyl acylate complex followed by UV irradiation. The gallery height, specific surface area and Ti content of the sample synthesized by using titanyl acylate complex were larger than that using TiO₂ sol solution. Furthermore, the photocatalytic activity of the TiO₂ pillared H₄Nb₆O₁₇ prepared using a titanyl acylate precursor was twice larger than that fabricated using a TiO₂ sol solution.