Techniques for the observation of micrometeorite craters in metal substrates utilizing electron micrographic replica methods

Thin film replica technique for obtaining high quality electron micrographs of craters in metal substrates formed by microscopic hypervelocity particle impac

A practice-led approach to facial animation research

In facial expression research, it is well established that certain emotional expressions are universally recognized. Studies into the observer perception of dynamic expressions have built upon this research by highlighting the importance of particular facial regions, timings, and temporal configurations to perception and interpretation. In many studies, the stimuli for such studies have been generated through posing by non-experts or performances by trained actors. However, skilled character animators are capable of crafting recognizable, believable emotional facial expressions as a part of their professional practice. ‘Emotional Avatars’ was conceived as an interdisciplinary research project which would draw upon the knowledge of animation practice and emotional psychology. The aim of the project was to jointly investigate the artistic generation and observer perception of emotional expression animation to determine whether the nuances of emotional facial expression could be artistically choreographed to enhance audience interpretation

Spectroscopy of Hadrons with b Quarks from Lattice NRQCD

Preliminary results from an extensive lattice calculation of the B, B_c, and \Upsilon spectrum at quenched \beta = 6.0 are presented. The study includes radially and orbitally excited mesons, and baryons containing b quarks. The b quarks are formulated using NRQCD; for light and c quarks, a tadpole-improved clover action is used.Comment: talk given at LATTICE98(heavyqk), 3 pages LaTeX, 2 Postscript figure

Force and energy dissipation variations in non-contact atomic force spectroscopy on composite carbon nanotube systems

UHV dynamic force and energy dissipation spectroscopy in non-contact atomic force microscopy were used to probe specific interactions with composite systems formed by encapsulating inorganic compounds inside single-walled carbon nanotubes. It is found that forces due to nano-scale van der Waals interaction can be made to decrease by combining an Ag core and a carbon nanotube shell in the Ag@SWNT system. This specific behaviour was attributed to a significantly different effective dielectric function compared to the individual constituents, evaluated using a simple core-shell optical model. Energy dissipation measurements showed that by filling dissipation increases, explained here by softening of C-C bonds resulting in a more deformable nanotube cage. Thus, filled and unfilled nanotubes can be discriminated based on force and dissipation measurements. These findings have two different implications for potential applications: tuning the effective optical properties and tuning the interaction force for molecular absorption by appropriately choosing the filling with respect to the nanotube.Comment: 22 pages, 6 figure

Stringent Phenomenological Investigation into Heterotic String Optical Unification

For the weakly coupled heterotic string (WCHS) there is a well-known factor of twenty conflict between the minimum string coupling unification scale, Lambda_H ~5x10^(17) GeV, and the projected MSSM unification scale, Lambda_U ~ 2.5x10^(16) GeV, assuming an intermediate scale desert (ISD). Renormalization effects of intermediate scale MSSM-charged exotics (ISME) (endemic to quasi-realistic string models) can resolve this issue, pushing the MSSM scale up to the string scale. However, for a generic string model, this implies that the projected Lambda_U unification under ISD is accidental. If the true unification scale is 5.0x10^(17) GeV, is it possible that illusionary unification at 2.5x10^(17) GeV in the ISD scenario is not accidental? If it is not, then under what conditions would the assumption of ISME in a WCHS model imply apparent unification at Lambda_U when ISD is falsely assumed? Geidt's "optical unification" suggests that Lambda_U is not accidental, by offering a mechanism whereby a generic MSSM scale Lambda_U < Lambda_H is guaranteed. A WCHS model was constructed that offers the possibility of optical unification, depending on the availability of anomaly-cancelling flat directions meeting certain requirements. This paper reports on the systematic investigation of the optical unification properties of the set of stringent flat directions of this model. Stringent flat directions can be guaranteed to be F-flat to all finite order (or to at least a given finite order consistent with electroweak scale supersymmetry breaking) and can be viewed as the likely roots of more general flat directions. Analysis of the phenomenology of stringent flat directions gives an indication of the remaining optical unification phenomenology that must be garnered by flat directions developed from them.Comment: standard latex, 18 pages of tex

An Infrared Color-Magnitude Relationship

We have investigated a sample of dusty supergiants and Mira variables and have found a roughly linear relationship between the absolute magnitude at 12 mum and the [l2]-[25] color. Both samples follow the same infrared color-magnitude relationship, whic

A prospective study of mortality from cryptococcal meningitis following treatment induction with 1200 mg oral fluconazole in Blantyre, Malawi.

OBJECTIVE: We have previously reported high ten-week mortality from cryptococcal meningitis in Malawian adults following treatment-induction with 800 mg oral fluconazole (57% [33/58]). National guidelines in Malawi and other African countries now advocate an increased induction dose of 1200 mg. We assessed whether this has improved outcomes. DESIGN: This was a prospective observational study of HIV-infected adults with cryptococcal meningitis confirmed by diagnostic lumbar puncture. Treatment was with fluconazole 1200 mg/day for two weeks then 400mg/day for 8 weeks. Mortality within the first 10 weeks was the study end-point, and current results were compared with data from our prior patient cohort who started on fluconazole 800 mg/day. RESULTS: 47 participants received fluconazole monotherapy. Despite a treatment-induction dose of 1200 mg, ten-week mortality remained 55% (26/47). This was no better than our previous study (Hazard Ratio [HR] of death on 1200 mg vs. 800 mg fluconazole: 1.29 (95% CI: 0.77-2.16, p = 0.332)). There was some evidence for improved survival in patients who had repeat lumbar punctures during early therapy to lower intracranial pressure (HR: 0.27 [95% CI: 0.07-1.03, p = 0.055]). CONCLUSION: There remains an urgent need to identify more effective, affordable and deliverable regimens for cryptococcal meningitis

Nanotube field of C60 molecules in carbon nanotubes: atomistic versus continuous tube approach

We calculate the van der Waals energy of a C60 molecule when it is encapsulated in a single-walled carbon nanotube with discrete atomistic structure. orientational degrees of freedom and longitudinal displacements of the molecule are taken into account, and several achiral and chiral carbon nanotubes are considered. A comparison with earlier work where the tube was approximated by a continuous cylindrical distribution of carbon atoms is made. We find that such an approximation is valid for high and intermediate tube radii; for low tube radii, minor chirality effects come into play. Three molecular orientational regimes are found when varying the nanotube radius.Comment: 14 pages, 9 figures, accepted for publication in Phys. Rev.