Interval Methods in Robot Navigation

Interval methods helped a robot designed by the University of Texas at El Paso (UTEP) team win a prestigious third place world-wide in the robot competition held during the American Association of Artificial Intelligence conference in Portland, Oregon, August 6-7, 1996.D. M. is currently with Nortel (Northern Telecom)     

Vietnam: appropriate management of a pediatric hospital in the context of limited resources

The presence of any pulsatile mass suggests an underlying aneurysm. When such masses occur in the buttock, the differential diagnosis includes aneurysms arising from branches of gluteal vessels or aneurysms developing in a persistent sciatic artery (PSA). The investigation and management of two patients with pulsatile masses are described. Review of the embryologic aspects of these masses and the important literature on the subject led to the conclusions that when a pulsatile buttock mass is encountered, an anomalous PSA should be suspected. A gluteal artery aneurysm can be treated by ligation or occlusion, but for a sciatic artery aneurysm surgical ablation is necessary and distal perfusion must be achieved postoperatively.     

Rayleigh scattering in ZrF4-based glasses

Light scattering in a 51.53 ZrF4 - 20.47 BaF2 - 5.27 LaF3 - 3.24 AlF3 - 19.49 LiF glass was investigated for the first time both as a function of wavelength and of angular distribution. The measured total scatter loss exhibits a characteristic Ray-leigh ?-4 dependence. The total scattering attenuation coefficient has been reduced to that of the best synthetic silica, and nearly reaches the theoretically predicted minimum.     

Optimum design of wideband selective absorbers with provision for specified included layers

A method is described for optimising the design of a selective solar absorbing multilayer on a reflective substrate whose effective surface impedance can be specified. Provision is made for up to two layers to be specified to suit possible special physical requirements and for absorption grading with depth through the multilayer.The concept of maximum power transfer expressed in terms of “reflection loss” from selectivity theory in multisection transmission lines is used instead of the reflection coefficients. This enables formulation as a non-linear constrained optimisation problem. Computational results show that good performance may require non standard materials and also show the importance of controlling the substrate surface impedance perhaps by surface roughness. The latter effect has been shown in recent separate experimental results.     

Finite element approximation for the wave-particle interaction in weakly turbulent plasmas

A finite element method is presented for the numerical treatment of two-dimensional quasilinear equations. The method is applied to the electron-beam-plasma interaction. Strong influence of the initial fluctuation level on the evolution of the turbulence has been found.     

Burn‐through resistance of fibre/felt materials for aircraft fuselage insulation blankets

Light‐weight fire barrier materials for aircraft thermal/acoustical insulation blankets were investigated. The burn‐through test on blankets inserted with these fire‐blocking materials was performed using a small‐scale kerosene burner apparatus. The burner system generated a turbulent flame at 1000°–1100°C and a front heat‐flux at 160–180 kW/m². The rear or back‐side heat flux of blankets and their corresponding burn‐through time were monitored by a computerized data acquisition system. The blankets with ceramic or polymeric fire barrier materials provided a significantly additional burn‐through time compared with the regular blankets. Blanket samples inserted with an alumino‐silicate‐based ceramic layer were not burned‐through after 6 min. For fire resistant polymeric‐based materials, the burn‐through time varied from 2 to 6 min. The burn‐through resistance was correlated with the stable structure of SiO₂ at high temperature for the ceramic sheets and with the formation of a char layer for polymeric layers.Copyright © 2002 John Wiley & Sons, Ltd.     

Lymphatic drainage of hypertonic solution from peritoneal cavity of anesthetized and conscious sheep

Lymphatic drainage of the peritoneal cavity may reduce ultrafiltration in continuous ambulatory peritoneal dialysis. We assessed lymphatic drainage of the peritoneal cavity in sheep under dialysis conditions by cannulation of the relevant lymphatic vessels and compared lymphatic drainage in anesthetized and conscious animals. Lymph was collected from the caudal mediastinal lymph node and the thoracic duct, both of which are involved in the lymphatic drainage of the ovine peritoneal cavity. Volumes of a hypertonic dialysis solution (50 ml/kg 4.25% Dianeal) containing 25 microCi 125I-human serum albumin were instilled into the peritoneal cavity, and lymph flows and the appearance of labeled protein in the lymphatic and vascular compartments were monitored for 6 h. Intraperitoneal pressures increased 4-5 cmH2O above resting levels after infusion of dialysate. On the basis of the appearance of tracer in the lymph, drainage of peritoneal fluid into the caudal lymphatic was calculated to be 3.09 +/- 0.69 and 14.14 +/- 2.86 ml/h in anesthetized and conscious sheep, respectively. Drainage of peritoneal fluid into the thoracic duct preparations was calculated to be 1.32 +/- 0.33 and 14.69 +/- 5.73 ml/h in anesthetized and conscious sheep, respectively. Significant radioactivity was found in the bloodstream, and at least a portion of this was likely contributed by the right lymph duct, which was not cannulated in our experiments.(ABSTRACT TRUNCATED AT 250 WORDS)     

Transmission properties of 2.55 ?m fluoride glass fibre

Data transmission and bandwidth measurements have been performed on a fluoride glass fibre at the 2.55 ?m minimum loss wavelength of the fibre, using a colour centre laser and an external waveguide modulator. Fibre modal dispersion limited the fibre bandwidth to 360 MHz.