SANS partial structure factor analysis for determining protein–polymer interactions in semidilute solution

Contrast variation small angle neutron scattering experiments reveal the nature of interactions between proteins and polymers in semidilute aqueous solution.

Structure and Electrical Conductivity of Liquid Pb-Bi Alloys

The knowledge of the physical properties of liquid Pb-Bi alloys and those of eutectic composition especially, is of high scientific and practical importance. In present paper temperature dependent electrical conductivity as well as thermoelectric power of liquid Pb-Bi eutectic (Pb-55.9%Bi) is studied in the framework of Ziman formalism through an electron-ion potential. Partial structure factor is calculated from the Faber-Ziman approach. The dependency of conductivity is interpreted alongwith various screening functions. The results are compared with experimental findings and the effect of screening function on conductivity is discussed. This elucidates that the conductivity data of liquid Pb-Bi system are in qualitative agreement with the nearly-free electron picture.

Electrical Resistivity of Liquid Al-Mg Binary Alloys

The knowledge of the physical properties of liquid Al-Mg binary alloys is of high scientic and practical importance. The Ziman formalism is used to study the concentration dependent electrical resistivity of liquid Al-Mg alloys through an electron-ion potential. Partial structure factor is calculated by using Ashcroft-Langreth equation. The results are compared with experimental findings and the effect of screening function on electrical resistivity is discussed. This reveals that the resistivity data of liquid Al-Mg system are in qualitative agreement with the nearly-free electron picture.

On the determination of partial structure functions in small-angle scattering exemplified by Al89Ni6La5alloy

A comparison between the resonant scattering curve obtained by anomalous small-angle X-ray scattering at the X-ray absorption edge of Ni and the complementary small-angle neutron scattering curve from an Al89Ni6La5alloy sample is reported. The sample does not comply with the two-phase approximation. The two resulting scattering curves are approximately proportional to each other in this particular case. The anomalous small-angle X-ray scattering resonant curve at the Ni absorption edge equals the Ni–Ni partial structure factor and, owing to the favourable neutron scattering lengths of Ni, La and Al, the neutron scattering curve is also proportional to that partial structure factor.

Phasing of resonant anomalous X-ray reflectivity spectra and direct Fourier synthesis of element-specific partial structures at buried interfaces

A formalism for model-independent determination of element-specific partial structures at buried interfaces using the phase-dependent behavior of resonant anomalous X-ray reflectivity (RAXR) data is described. Each RAXR spectrum (i.e.reflectivityversusenergy at a fixed momentum transfer near the absorption edge of interest) is uniquely constrained by the amplitude and phase of the resonant partial structure factor with pre-determined non-resonant total structure factor and anomalous dispersion corrections of the resonant species. The element-specific partial density distribution is then imaged by discrete Fourier synthesis with the partial structure factor. The utility of this approach is demonstrated in the comparison of Rb+and Sr2+distributions at muscovite (001)–aqueous solution interfaces derived by model-independent and model-dependent approaches. This imaging method is useful for rapid determination of complex buried interfacial structures where element-specific atomic distributions are poorly constrained by conventional X-ray reflectivity analysis.