Models of polymers can generally be divided into two classes: (a) flexible, wherein bond lengths and valence angles are constrained to nearly constant values by strong, harmonic potentials, and (b) rigid, wherein the constrainb are geometric, Le., fixed bond lengths and angles. In general, the statistical mechanics of such systems differ. By introduction of a compensating potential based on the...

* Corresponding author – [email protected] Tel: 414-229-4126 Fax:414-229-6958 ABSTRACT Understanding the tribological aspects of machining processes is essential for increasing the dimensional accuracy and surface integrity of products. In the present investigation, orthogonal metal cutting simulations were performed using an explicit finite-element code, LS-DYNA. In the simulations, a rigid stee...

To improve the characterization of blood flows, we propose a method which makes it possible to use the spectral analysis of the Doppler signals. Our calculation induces a reasonable approximation, the error made on estimated speed reflects the fact that speed depends on the flow conditions as well as on measurement parameters like the bore and the volume flow rate. The estimate of the Doppler s...

Abrasive flow polishing plays an important part in modern ultra-precision machining. Ultrafine particles suspended in the medium of abrasive flow removes the material in nanoscale. In this paper, three-dimensional molecular dynamics (MD) simulations are performed to investigate the effect of impacting direction on abrasive cutting process during abrasive flow polishing. The molecular dynamics s...

complains of an audible, and often palpable, grating and snapping sound on shoulder girdle movements. Scapular movements are uncomfortable, and the noise can often be localised by the examiner to a specific part of the scapulo-thoracic “joint”. The condition was first described by Boinet in 1867 when he presented a young man of nineteen with discomfort on scapular movements and “une cr#{233}pit...

We present an interactive technique on virtual contact handling for avatars in virtual environments using XXX. If a contact has occurred between an articulated avatar and a virtual environment, the global penetration depth and contact points are estimated based on a fast local penetration depth computation for decomposed convex pieces. The penetration depth and contact information are used for ...

We present an interactive technique on virtual contact handling for avatars in virtual environments using geometry-driven physics. If a contact has occurred between an articulated avatar and a virtual environment, the global penetration depth and contact points are estimated based on a fast local penetration depth computation for decomposed convex pieces. The penetration depth and contact infor...

BACKGROUND Although much has been written on the implications of friction generated between orthodontic archwires and labial brackets, information on lingual brackets is still limited. Hence, we set out to investigate the frictional resistance exerted by different lingual and labial brackets, including both conventional and self-ligating designs. The effect of various factors, namely bracket/ba...

Snakes are one of the world’s most versatile locomotors, at ease slithering through rubble or ratcheting up vertical tree trunks. Their adaptations for movement across complex dry terrain thus serve naturally as inspirations for search-and-rescue robotics. In this combined experimental and theoretical study, we perform experiments on inclined surfaces to show that a snake’s scales are critical ...

Root caps provide a protective layer in front of the meristem that protects the meristem from abrasion by soil particles. The continuous production and sloughing of the root cap cells may be an adaptation to decrease the friction at the soil-root interface by acting as a low-friction lining to the channel formed by the root. Experiments were performed which provide the first direct evidence tha...