A polycrystalline sample of Al63Cu25Fe12 has been studied as a function of thermal treatment by positron annihilation and X-ray diffraction techniques. Results suggest the presence of an icosahedral-to-rhombohedral microcrystalline phase transition near 300-degrees-C. Below this transition, a large ...

Structural studies of conventionally solidified Al80-2xPd20CrxFex alloys have shown that the formation of a well ordered icosahedral phase occurs for a composition where the free-electron Fermi sphere is coincident with the first pseudo-Brillouin zone boundary. This condition indicates the importanc...

We examined the influence of habitat characteristics at the microhabitat, macrohabitat, and landscape spatial scales on small mammals occurring in 12 forest patches within four agricultural landscapes of Prince Edward Island (Canada). Landscape features were important determinants of small mammal va...

The anisotropic intermolecular forces responsible for the orientational ordering in liquid crystals are probed by comparing Monte Carlo (MC) simulations with experimental nuclear magnetic resonance (NMR) results for solutes in nematic liquid crystals. In a special liquid crystal mixture where all lo...

Monte Carlo simulations were used to study orientational ordering of solutes in a nematic phase. Nematogens were modelled as hard prolate ellipsoids with an axis ratio of 5:1. Solutes were also modelled as hard prolate ellipsoids, with a variety of sizes and shape anisotropies. Solute order paramete...

Multiple-quantum H-1 NMR spectroscopy was used to simplify the analysis of the complicated one-quantum spectrum of the 10-spin molecule biphenyl dissolved in a nematic solvent. An eight-quantum spectrum was analyzed to obtain estimates of all dipolar coupling constants and chemical shifts, which wer...

Solid-state H-2 NMR powder spectra and T-1 longitudinal relaxation data have been collected for carceplexes containing benzene and acetonitrile guest molecules. Analysis of the data suggests that benzene rotates rapidly about its C-6 axis with an activation energy of 25.8 +/- 0.4 kJ mol(-1). In addi...

In this study we use multiple-quantum H-1-NMR spectroscopy to study butane, the simplest flexible alkane, dissolved in a nematic solvent. An analysis of the highly accurate H-1 dipolar coupling constants gives important information about conformational and orientational behavior, including the hans-...

Deuterium NMR measurements are reported for two types of onium salts: (CH3)3E+I-, where E = O (counterion is BF4-), S, Se, or Te, and C6H5M(CH3)3+I-, where M = N, P, or As. Within each class of compounds the activation energy for rotation of the trimethyl groups about the C3' axis increases wit...

Deuterium NMR spectra for solid [H-2(9)]tris(trimethylsilyl)amine were recorded at 77 K and in the region 114-353 K. At 77 K there is only fast rotation of the methyl groups. Between 122 and 171 K rotation of the trimethylsilyl groups and of the entire molecule (about its C3 axis) affect the deuteri...

Deuterium nuclear magnetic resonance (NMR) spectra and spin-lattice relaxation times are used to investigate the guest and host molecular dynamics of solid 1,4-di-tert-butylbenzene-d4 (DTBB-d4), 1,4-di-tert-butylbenzene-d18 (DTBB-d18), the thiourea/ 1,4-di-tert-butylbenzene-d4 inclusion compound (TU...

Deuterium nuclear magnetic resonance (NMR) spectra and spin-lattice relaxation times were determined in order to study the dynamics of t-butyl groups in butylated hydroxytoluene. The results are consistent with a model first proposed by Beckmann et al. [J. Magn. Reson. 36, 199 (1979)], where there i...

In this work, we examine some of the properties of a model Langmuir monolayer, which consists of surfactant molecules (amphiphillic organic molecules) deposited onto a water subphase. The surfactants are modeled as rigid rods composed of a head and tail segment. The tails consist of 'nt' ≈ 4-...

A coarse-grained model for surfactant molecules adsorbed at a water surface is studied at zero temperature to elucidate ground-state tilt ordering. The surfactants are modeled as rigid rods composed of head and tail segments, where the tails consist of effective monomers representing methylene CH2 g...