It is shown for the Co-B series that changes in the temperature coefficient of resistivity, a , produced by a few percent of crystals within an amorphous matrix, are of the same order as changes of a with composition which have been reported in the literature, and interpreted in terms of physics of the amorphous state. Such low levels of crystalline fraction may escape notice by the standard me...

Thermal analysis of solution cast mixtures of poly(viny1idene fluoride) (PVF2) and poly(methy1 methacrylate) (PMMA) has been carried out with various programmed temperature profiles. Results from experiments conducted in a quasi-equilibrium state show that PVF:! crystallizes in the mixture upon cooling. Furthermore, depressions were observed in the melting and the crystallization temperatures. ...

Using an ultrafast scanning microcalorimetry apparatus capable of heating rates in excess of 10(5) Ks, we have conducted the first direct measurements of thermodynamic properties of pure and doped amorphous solid water (also referred to as low density amorphous ice) in the temperature range from 120 to 230 K. Ultrafast microcalorimetry experiments show that the heat capacity of pure amorphous s...

Photodesorption of O(2)(X (3)Σ(g) (-)) and O(2)(a (1)Δ(g)) from amorphous solid water at 90 K has been studied following photoexcitation within the first absorption band at 157 nm. Time-of-flight and rotational spectra of O(2) reveal the translational and internal energy distributions, from which production mechanisms are deduced. Exothermic and endothermic reactions of OH+O((3)P) are proposed ...

The Problem: How can biological cells grow to form complicated shapes? In our approach to this question, we model cells as simple immobile computing units with the ability to replicate and pass messages. Motivation: A primary goal of this project is to better understand how biological cells grow into complex structures. This work will also provide insight into a new computing paradigm, namely A...

Radiation and thermally induced changes in the oxidation state of uranium in metamict zircon have been systematically analysed, for the first time, using polarized near-infrared spectroscopy. The results showed that in damaged zircon U ions in crystalline domains exhibited relatively sharp, anisotropic signals from tetravalent and pentavalent U ions in crystalline domains (U4+ crystal and U5+ c...

Based on first-principles density-functional calculations, we present the structure and diffusion of boron in amorphous silica, as well as in crystalline silica for comparison purpose. We find that incorporation of a boron atom into the amorphous silica matrix results in various minimum-energy configurations with and without oxygen deficient centers, and also the B-related defects can undergo i...

Systems undergoing an equilibrium phase transition from a liquid state to an amorphous solid state exhibit certain universal characteristics. Chief among these are the fraction of particles that are randomly localized and the scaling functions that describe the order parameter and ~equivalently! the statistical distribution of localization lengths for these localized particles. The purpose of t...

Poly(L-lactic acid), PLLA, in amorphous and semi-crystalline forms were studied by DSC, in order to investigate both molecular dynamics and structural relaxation features, and to understand the influence of the crystalline confinement on the segmental mobility of the intraspherulitic amorphous phase. Experimental data were generated after submitting the materials to different thermal histories ...

Solutions of maltodextrins (MD) with the dextrose equivalent (D.E.) 9-12 and D.E. 23-27 were mixed with lactose solutions at different ratios. Freeze-dried amorphous solids of lactose and lactose-MD were prepared from solutions containing 20% total solids. The ratios of lactose and MD were 90:10, 80:20, and 70:30 (w/w). Crystallization rate of amorphous lactose was followed from changes in wate...