An Interactive Empirical Approach to the Validation of Software Package Specifications

The objective of this research is the development of a practical system to manipulate and validate software package specifications. The validation process developed is based on consistency checks. Furthermore, by means of scenarios, the customer will be able to interactively experience the specified system prior to its implementation. Functions, data, and data types constitute the framework of our validation system. The specification of the Graphical Kernel System (GKS) is a typical example of the target software package specifications to be manipulated

Discovery of Selected Water Dispensers by Newborn Pigs

Newborn pigs in 86 litters were offered drinking water from four types of dispenser to determine how quickly each design would be discovered. On average piglets discovered water within about 24 h from an exposed water surface (bowl or cup), whereas discovery time was delayed to more than 72 h with nipple or push-lever dispensers. A prototype dispenser with a wide bowl and continuous bubbling action reduced (P \u3c 0.05) average discovery time to about 14 h

Modifying water nipples for newborn pigs

The use of bite nipples by piglets during the first six days after birth was monitored by time-lapse video recording. Simple bite nipples, mounted at a downward angle, were not discovered by most piglets within the six days, even after the nipple had been modified to drip water continuously. However, two modifications resulted in most piglets discovering the nipple within three days. These modifications were (1) mounting the nipple close to the floor with an upward angle and (2) adding a short length of chain to the valve leve

Weakly-bound rare isotopes with a coupled-channel approach that includes resonant levels

The question of how the scattering cross section changes when the spectra of the colliding nuclei have low-excitation particle-emitting resonances is explored using a multi-channel algebraic scattering (MCAS) method. As a test case, the light-mass nuclear target 8Be, being particle-unstable, has been considered. Nucleon-nucleus scattering cross sections, as well as the spectra of the compound nuclei formed, have been determined from calculations that do, and do not, consider particle emission widths of the target nuclear states. The resonant character of the unstable excited states introduces a problem because the low-energy tails of these resonances can intrude into the sub-threshold, bound-state region. This unphysical behaviour needs to be corrected by modifying, in an energy-dependent way, the shape of the target resonances from the usual Lorentzian one. The resonance function must smoothly reach zero at the elastic threshold. Ways of achieving this condition are explored in this paper.Comment: Contribution presented at INPC 2010, Vancouve

First-passage theory of exciton population loss in single-walled carbon nanotubes reveals micron-scale intrinsic diffusion lengths

One-dimensional crystals have long range translational invariance which manifests as long exciton diffusion lengths, but such intrinsic properties are often obscured by environmental perturbations. We use a first-passage approach to model single-walled carbon nanotube (SWCNT) exciton dynamics (including exciton-exciton annihilation and end effects) and compare it to results from both continuous-wave and multi-pulse ultrafast excitation experiments to extract intrinsic SWCNT properties. Excitons in suspended SWCNTs experience macroscopic diffusion lengths, on the order of the SWCNT length, (1.3-4.7 um) in sharp contrast to encapsulated samples. For these pristine samples, our model reveals intrinsic lifetimes (350-750 ps), diffusion constants (130-350 cm^2/s), and absorption cross-sections (2.1-3.6 X 10^-17 cm^2/atom) among the highest previously reported.and diffusion lengths for SWCNTs.Comment: 6 pages, 3 figure

Low energy nuclear scattering and sub-threshold spectra from a multi-channel algebraic scattering theory

A multi-channel algebraic scattering theory, to find solutions of coupled-channel scattering problems with interactions determined by collective models, has been structured to ensure that the Pauli principle is not violated. Positive (scattering) and negative (sub-threshold) solutions can be found to predict both the compound nucleus sub-threshold spectrum and all resonances due to coupled channel effects that occur on a smooth energy varying background.Comment: 5 pages, 4 figures, FINUSTAR conference, Kos, Greece, Sept. 200