Search results for "VOLUME"
showing 10 items of 1932 documents
A discrete-element model for viscoelastic deformation and fracture of glacial ice
2015
a b s t r a c t A discrete-element model was developed to study the behavior of viscoelastic materials that are allowed to fracture. Applicable to many materials, the main objective of this analysis was to develop a model specifically for ice dynamics. A realistic model of glacial ice must include elasticity, brittle fracture and slow viscous deformations. Here the model is described in detail and tested with several benchmark simulations. The model was used to simulate various ice-specific applications with resulting flow rates that were compatible with Glen's law, and produced under fragmentation fragment-size distributions that agreed with the known analytical and experimental results.
Apparent and Real Distribution in GPC (Experiments with PMMA Samples)
1971
Abstract Molecular weight distribution curves obtained by GPC are broadened if concentration and flow rate are fixed in the usual range. Therefore, the apparent nonuniformity U app of the samples is larger than the real non-uniformity U = (Mw/Mn) −1. For a number of fractionated and unfractionated samples of polymethyl methacrylate we determined M n and M w by osmotic, light-scattering, and viscosity measurements. Thus, the real value of U can be compared to U app obtained by GPC at different concentrations and flow rates, υ. The excess nonuniformity U exc is evaluated as function of concentration c, polydispersity, molecular weight, and flow rate. For c = 0 and υ = 0, U exc is not far from…
Physico-chemical properties of dense water/copper(II) bis(2-ethylhexyl) sulfosuccinate/CCl4 microemulsions
2007
Measurements of some physico-chemical properties (density, viscosity, conductance, infra-red spectra) of water/copper(II) bis(2-ethylhexyl) sulfosuccinate (Cu(DEHSS)2)/CCl4 microemulsions, as a function of the volume fraction O of the dispersed phase (0 < O < 0.6) and of the molar ratio R (R = [water]/[DEHSS−]), have been performed at 25 °C. At each value of R, the density of the micellar phase is practically independent of O whereas the viscosity of microemulsions diverges above threshold O values. A divergent behavior for the electrical conductivity has also been observed but only at certain R values. These results, together with those from infra-red spectra, suggest that in percolated mi…
Assessment of spatial perception for a multi-layer volumetric display: the effect of exocentric and egocentric distance on relative depth judgements
2020
Three-dimensional images on multiple depth layers of the volumetric display provide the physiological depth cues which ensure the high precision of depth judgements at close viewing distances and enhance the user experience. However, the contribution of physiological cues declines with an increase of viewing distance (egocentric distance), and the human spatial perception varies depending on the inter-stimuli distance (exocentric distance). We conducted a psychophysical experiment to test the perception of three-dimensional images rendered on the volumetric display depending on exocentric and egocentric stimuli distance. The constant angular size visual stimuli were displayed on different d…
Looking in Depth: Visual Distance Perception of Stimuli on Volumetric Multi-Planar Display
2018
Ability to distinguish relative location of visual stimuli on a multi-planar display was evaluated within psychophysical experiment in order to figure out the impact of physical distance between stimuli across depth of volumetric data.
Visual Search Performance Depending on Target-Distractor Difference on Volumetric Display and Flat Panel Display
2019
The search items were demonstrated on the volumetric display and flat panel display. In contrast to the correct response rate, the search time and number of interactions were considerably affected by the type of visualization.
Visual search in three-dimensional non-medical images: visual-motor performance of radiologists
2019
The visual search abilities of radiologists are systematically trained due to the specifics of their professional tasks. We investigated whether the visual-motor performance of radiologists, residents and students varied when searching non-medical targets on the volumetric display. As a result, no significant differences were found in the correct response rate among three groups. However, the total number of interactions was considerably higher for the resident radiologists and medical students comparing to the experienced radiologists. Our results suggest that the radiological experience does not interfere with the outcome in the developed visual search task, but may be reflected in motor …
Effects of a structured educational intervention in moderate-to-severe elderly asthmatic subjects.
2019
Background: Adherence to inhaled drugs is linked to patients’ satisfaction with their device, and an incorrect use can negatively affect the outcomes of asthma treatment. We speculated that this is particularly true in elderly asthmatic subjects. Aim: We performed a national pre-post interventional multicentre study, enrolling moderate-to-severe asthmatic subjects aged ≥65 years treated with fixed inhaled combination drugs by dry powder inhaler (DPI) or pressurized metered dose inhaler (pMDI). Adherence and critical errors were evaluated by means of validated questionnaires at first visit (V1) and after 3–6 months (V2). At V1, subjects underwent intensive training on the correct use of the…
The Flow-Volume-Measurement in Computer-Supported Lung Function Analysis
1982
For some years computers have been applied more and more in pulmonary function laboratories. On the one hand the medico-technical industry could connect older diagnostic systems with new calculators, on the other hand completely computerised lung function desks have been developed.
Age-dependent differences in the effect of phenprocoumon on the vitamin K1-epoxide cycle in rats
1980
Abstract The anticoagulant activity and the pharmacokinetics of phenprocoumon as well as the effect of phenprocoumon on the vitamin K1-epoxide cycle in younger (12 weeks) and older (36 weeks) male inbred Lewis rats has been examined in a study of the mechanism responsible for the increase in the responsiveness to oral anticoagulant drugs (OAD's) with increasing age. After a single i.v.-dose of phenprocoumon (0†355 mg kg−1 the anticoagulant effect obtained was greater in older than in younger rats. There were no differences between younger and older rats in the rate of elimination, volume of distribution and in the free fraction and free concentration values of phenprocoumon in plasma and li…