Physical models for the visualization of animated images "from the physical model to the eye"

ISSN: 1017-4656International audienceThe creation of animated images consists of working on both movement and image itself. This paper falls within the framework of a reflection on the properties of image and its creation processes within the double context of animation and artistic creation. The first part of this paper is a general presentation of the problem and the different research questionings that it raises. The following part is a presentation of the first studies that we have carried out on these subjects. We will briefly examine the situation of image synthesis today in order to propose image creation modalities that be better suited to artistic creation than those that are usually used for realistic visualization. In the case of animated images, the properties inherent in motion and those inherent in each image reinforce or cancel each other depending on each individual case. Consequently, we must study the properties of images when it is meant to support motion

Modelling, Simulating, and Visualizing Granular Materials

International audienceThe shape and the motion of dunes are most impressive and beautiful scenes. Granular materials in general and sand in particular display a variety of behaviours, that are in many ways different from those of either liquids or solids. These behaviours are very partially understood. The objective of this work is, on the one hand, the understanding of the macroscopic behaviour of this type of material, and on the other hand, the achievement of animation sequences for artistic purposes. The grain models described here were implemented and simulated according to the Cordis-Anima formalism. This means that physical objects in general, and granular material in particular, are considered as a set of punctual masses linked together by linear or non-linear spring-damper interactions. These granular objects were visualized thanks to the engraved screez algorithm : this "screen" is a physically simulated carving plate acting as a visualization support. The models and simulations produced here account for complex phenomena such as the constitution of a pile from independant particles, as well as avalanch and internal collapse phenomena

Comparison of pure palm olein oil, hydrogenated oil-containing palm, and canola on serum lipids and lipid oxidation rate in rats fed with these oils

Due to increased consumption of canola oil and hydrogenated oil containing palm and palm olein, and their possible effects on serum lipoproteins, the present study was conducted to determine the effects of these oils on lipids and lipid oxidation level. Methods: In this experimental study, 88 Wistar rats were randomly assigned to four groups. Control group (A) was on a normal diet. Groups B, C, and D, in addition to normal diet, were fed with hydrogenated oil-contained palm oil, pure palm olein oil, and canola oil, respectively for 4 weeks. Serum Biochemical factors [total cholesterol (TC), triglyceride (TG), LDL, HDL, LDL/HDL ratio, oxLDL, paraoxanase-1 (PON1), and malondialdehyde (MDA)] were measured. Results: The lowest mean serum TC was seen in the control group and the highest in the group B. There were differences in TC, TG, HDL, MDA, and PON1 between the control group and other groups (P0.05). MDA was higher in groups C and D. Conclusion: Canola oil, hydrogenated oil-containing palm and palm olein may increase atherosclerosis risk through decreasing PON1 activity and elevating oxLDL. Palm olein oils in rats' diets cause a considerable decrease in LDL and help to increase HDL

Characterization of aerosols in an underground mine

“Diesel-powered engines are a common source of submicron carbon-rich particles. Characterizing morphological and physical attributes of diesel agglomerates is therefore of great importance to be able to identify the source and improve removal technology. Size-segregated sampling was conducted in two phases of underground experiments. Scanning transmission electron microscopy and fast mobility particle sizers were used to determine the size distribution of agglomerates based on particle mobility and projected area diameter. Controlled zone sampling test results were used to determine the morphological characteristics of agglomerates for specific types of diesel equipment both with and without removal strategies. Changes in fractal dimension, shape factor and primary particle diameter were observed for examined control strategies as well as light duty and heavy duty engines. Samples collected from uncontrolled zone showed higher fractal dimension of chain-like agglomerates. Volatile carbon particles were found on the surface of dust particles at the interaction point with diesel agglomerate. EDS measurements were used to identify chemical traces of dust related elements and identify the source of chain-like agglomerates. Controlled zone results showed the size distribution decreased for the agglomerates emitted from engines with newer technology. Three types of chain-like agglomerates were identified during image analysis: chain-like agglomerates with graphitic structure, amorphous carbon-rich agglomerates, and chain-like agglomerates with intrinsic catalyst. Size segregated sampling followed by microscopic and chemical analysis assisted to determine detailed characterization and source apportionment of aerosols in the underground atmosphere”--Abstract, page iii

Acute Myocardial Infarction following Naltrexone Consumption; a Case Report

Cardiovascular effects of opioid withdrawal have long been studied. It was reported that patients with underlying ischemic heart disease and atherosclerotic vessels may be complicated by a sudden physical and emotional stress due to withdrawal syndrome. But some other believes sudden increase in catecholamine level as a sympathetic overflow might effect on heart with and without underlying ischemia. In the current study, a patient on methadone maintenance therapy (MMT) who experienced myocardial infarction (MI) after taking naltrexone was described

A multi-scale physical model of granular materials

International audienceGranular materials display a certain number of properties that have long been observed but only partially understood. Some resemble the properties of solids, some resemble the properties of fluids and others are unique. The concept on "fourth state of matter" has been mentioned. This is perhaps precisely the reason why these materials are so fascinating and beautiful. Thus the aim of this work is both a better physical understanding of the causes of these phenomena in properties of individuals grains and the achievement of realistic and beautiful animation sequences by the physical simulation of these grains