Application of the complex model to liquid metal-salt systems

The complex model developed by Hoch and Arpshofen is used to describe the phase diagram of several alkali halide-alkali metal systems. In the first approximation, Δ_m^ex = ΔH_m = n(x ? xⁿ)w where n is the size of the complex (number of atoms), W is the interaction parameter, and x is the atom fraction of the compoennt with the lower binding capcacity. In several systems the complete form of the above equation is applied, including deviation from ramdomness and vibrational entropy contributions.If the liquid is single-phase, the data are calculated from the liquidus line. If a miscibility gap exists in the liquid, it is used to calculate the parameters.The model requires only two constants (n and W), and thus can be used to calculate phase diagrams, where relatively little information is available. As an example, the calculation of the U-UO₂, Th-ThO₂ phase diagram is outlined.     

The ternary system aluminum-gold-silicon

We calculated the two pseudobinary systems Al₂Au---Si and AlAu₂---Si and the Si liquidus surface at 1373 K. The Al---Au and Al---Si binary systems reported by Massalski and Hultgren agree with each other, but differences are present in the Au---Si system. In the Al---Si system the Si liquidus extends over a temperature range of 800 K, and in the Au---Si system over 1000 K. This permits us to check the new equation for the difference in Gibbs energy G(l-s) and specific heat C_p(l-s) derived from the consideration of T_glass, the theoretical glass transition temperature. For the liquid solutions we used the Hoch-Arpshofen model.

The only available ternary experimental data are the Si liquidus compositions at 1373 K obtained by Lozovdkiy and Politova. The agreement between experimental and calculated data is very good. The calculated eutectic compositions and temperatures are as follows: for the system a eutectic temperature of 1.195 and an Si content x = 0.175; for the system a eutectic temperature of 0.760 and an Si content x = 0.113.     

Expression of inducible nitric oxide synthase in human burn wounds

A water-soluble synthetic peptide with only nine amino acid residues, comprising the 131-139 sequence region of the cytotoxic protein alpha-sarcin (secreted by the mold Aspergillus giganteus), interacts with large unilamellar vesicles composed of acid phospholipids. It promotes lipid mixing between bilayers and leakage of vesicle aqueous contents, and it also abolishes the phospholipid phase transition. Other larger peptides containing such an amino acid sequence also produce these effects. These peptides acquire alpha-helical conformation in the presence of trifluoroethanol, but display beta-strand conformation in the presence of sodium dodecyl sulfate. The interaction of these peptides with the lipid vesicles also results in beta-structure. The obtained data are discussed in terms of the involvement of the 131-139 stretch of alpha-sarcin in its interaction with lipid membranes.     

Equation of state of uranium oxide

The total and partial pressures over liquid UO₂ have been measured and calculated up to 5000K. A review of previous work is given. The equation of state of UO₂ as the main constituent of the fast breeder oxide fuel is required up to at least 5000K in order to estimate the energy release in a loss of flow (LOF) driven hypothetical core disruptive accident (HCDA) of the liquid metal fast breeder reactor (LMFBR).Two models, a macroscopic “mixture” model and a microscopic “defect” model have been developed to determine the oxygen potential of UO₂₀₀ up to 5000 K.A combination of mass spectrometric, Langmuir probe and high tension diode studies, applied for the first time to the laser vaporization process, revealed large quantities of ions emitted directly from the surface, and resolved previous discrepancies between measured and calculated vapour pressures by an enhanced rate of evaporation due to ion emission. As shown theoretically intrinsic ion emission can contribute to the net evaporation rate only if the resulting positive space charge can be neutralised. It is proposed that this can be accomplished by the presence of “hot” electrons in the plasma.The recommended equilibrium total pressure over liquid UO_2.00, valid between the melting point and 5000K, is $\text{log p (MPa) = ? 2.717 ? 20131/T + 1.925}\text{log T}$.     

Homeless in the United States

The way public authorities presently define the homeless in the United States carries forward a complex historical legacy. The causal and moral assessments of the homeless, grounded in the work ethic of our capitalist society, have left behind four interpretations of the homeless as vagrant, deviant, sick or victim. Analysis of recent studies of the homeless, while uncovering the presence of all four definitions, found that most of the ‘new’ homeless are victims of the economy or sick.     

A method for rapid filling of fine-tipped micropipettes with electrolyte solutions including those containing horseradish peroxidase

Cooling the tips of micropipettes pulled from filament-containing capillary glass dramatically increases the rate and completeness of filling with a variety of electrolyte solutions. In tests with solutions containing horseradish peroxidase this method increased the completeness of filling by more than two orders of magnitude.