Rheo-attenuated total reflectance infrared spectroscopy: a new tool to study biopolymers

Whilst rheology is the reference technique to study the mechanical properties of unspun silk, we know little of the structure and the dynamics that generate them. By coupling infrared spectroscopy and shearing forces to study silk fibroin conversion, we are introducing a novel tool to address this gap in our knowledge. Here the silk conversion process has been studied dynamically using polarized attenuated total reflectance Fourier transform infrared spectroscopy whilst applying shear, thus revealing silk protein conformation and molecular orientation in situ. Our results show that the silk conversion process starts with a pre-alignment of the proteins followed by a rapid growth of the β-sheet formation and then a subsequent deceleration of the growth. We propose that this tool will provide further insight into not only silk but any biopolymer solution, opening a new window into biological materials.     

Baer ordered *-fields of the first kind

We construct examples of Baer ordered *-fields of the first kind of every dimension 4 ⁿ ,n=1,2,….     

Ohkuma Structures

The construction and characterization by T. Ohkuma of a chain whose automorphism group acts uniquely transitively is extended in this article to analogues for circularly ordered sets and betweenness chains.     

Polysiloxane Interpenetrating Network Materials as Electronic Device Encapsulants: Synthesis and Properties

Thermally curable interpenetrating networks employing short and long chain components were successfully prepared via the sol-gel route. Their mechanical properties were assessed and correlated to their composition and structure. The role of the organic cross-links was found to be a larger determinant of the mechanical properties than the inorganic network. Their low frequency dielectric properties were investigated and found to be comparable to those of conventional encapsulation materials. Observed mass losses at 523 K ranged between 3–5% after 1000 minutes, the suspected mechanism being the development of organic cross-links.     

Some relations between additive functions,II

Aequationes mathematicae -     

On the system of functional equationsf(x + y) = f(x) + f(y) andf(xy) = p (x)f(y) + q(y)f(x)

Aequationes mathematicae -     

Predicting transport properties without adjustable parameters: A test application of the Hulburt-Hirschfelder potential to argon

Accurate estimates of the transport properties of gaseous systems under conditions where experimental transport data are sparse of unavailable are important in a number of applications. The Hulburt-Hirschfelder (HH) potential for monatomic gas interactions, which is determined entirely by spectroscopic constants of diatomic molecules, provides a basis for calculating transport properties without adjustable parameters. In this paper we report test calculations of the viscosity, thermal conductivity and self-diffusion coefficients for argon. Comparison with the comprehensive correlation of thermophysical properties for argon by Kestin and co-workers shows very reasonable agreement for the transport properties at moderate and high temperatures. Deviations at lower temperatures may be attributed to inaccuracies in the long-range part of the HH potential, whereas the core and well of the potential appear to be adequately represented. These results strongly support the use of the HH potential for estimating the transport properties of monatomic gases at high t