The paper focuses on bio®lms subject to turbulent ̄ow and high liquid velocity (of the order of 1 m s) which can be found in heat exchangers, water distribution systems and in some wastewater reactors. An overall model describing bio®lm development is presented, which includes the effects of biomass detachment due to the hydrodynamic forces. A methodology for estimating substrate consumption fr...

Using an airway management training model, we have assessed anaesthesia personnel in their use of correct cricoid force and ability to retain this skill after a short training programme. A perspex device, working on a hydraulic principle, was used to measure cricoid pressure when applied to the model. After initial assessment at two levels of cricoid force (20 and 40 N), participants undertook ...

A new emitter-detector-cuvette assembly for the standard PAM fluorometer is described which leads to substantial improvement of signal/noise ratio and increased flexibility with respect to the choice of excitation and emission wavelengths. These features are particularly useful for work with very dilute suspensions of unicellular algae and isolated chloroplasts. Instead of fiber optics perspex ...

Background: In treating patients with radiation, the degree of accuracy for the delivery of tumor dose is recommended to be within ± 5% by ICRU in report 24. The experimental studies have shown that the presence of low-density inhomogeneity in areas such as the lung can lead to a greater than 30% change in the water dose data. Therefore, inhomogeneity corrections should be used in treatment pla...

Detailed neuroanatomical information is an essential prerequisite for functional analysis of specific neurones in the central nervous system. In this investigation we have combined the dissection of single axons with cobalt-backfilling to reveal the structural organisation of a class of interganglionic giant interneurones in the central nervous system of the cockroach, Periplaneta americana (L)...

The possibility that the autonomic nervous system may influence the function of intestinal mucosa was investigated by assessing the effect of acetyl choline on ion transport in human intestine. Isolated pieces of stripped ileal mucosa were mounted in Perspex flux-chambers and bathed in isotonic glucose Ringer's solution. Acetyl choline caused a rise in mean potential difference (8.8-12.3 mV, P ...

The enhancement of heat transfer from fuel rods to coolant of a Liquid Metal Fast Reactor (LMFR) decreases the fuel temperature and, thus, improves the safety margin of the reactor. One of the mechanisms that increases heat transfer consists of large coherent structures that can occur across the gap between adjacent rods. This work investigates the flow between two curved surfaces, representing...

PURPOSE To compare the image quality and dosimetry on the Varian cone beam computed tomography (CBCT) system between software Version 1.4.13 and Version 1.4.11 (referred to as "new" and "old" protocols, respectively, in the following text). This study investigated organ absorbed dose, total effective dose, and image quality of the CBCT system for the head-and-neck and pelvic regions. METHODS ...

BACKGROUND During eye rotations the vitreous humour moves with respect to the eye globe. This relative motion has been suggested to possibly have an important role in inducing degradation of the gel structure, which might lead to vitreous liquefaction and/or posterior vitreous detachment. Aim of the present work is to study the characteristics of vitreous motion induced by eye rotations. METH...

Contrast sensitivities were measured in human observers of different ages in response to sinusoidal grating patterns generated by laser interferometer and cathode ray tube (c.r.t.). The former method bypasses the effects of the optical media to assess directly the contrast sensitivity of the retina/visual system, while the over-all assessment including optical media is made to the c.r.t. displa...