Rolling resistance modelling in the Celtic stone dynamics

The rolling stone.

Figure 1a. Contrast enhanced CT demonstrating a small calcified gallstone (arrow) within the gallbladder. 1b+c. Contrast enhanced CT two weeks later. b. A dilated gallbladder with thickened wall, absence of stone, and intrahepatic bile duct dilatation (arrow). 1c. The migrated gallstone (arrow) is seen in the distal CBD. 1d. ERCP demonstrating a filling defect in the distal CBD. 1e. The extract...

Letters to the editor: like a rolling stone?

the study of bright and surface discrete cavity solitons dynamics in saturable nonlinear media

امروزه سالیتون ها بعنوان امواج جایگزیده ای که تحت شرایط خاص بدون تغییر شکل در محیط منتشر می-شوند، زمینه مطالعات گسترده ای در حوزه اپتیک غیرخطی هستند. در این راستا توجه به پدیده پراش گسسته، که بعنوان عامل پهن شدگی باریکه نوری در آرایه ای از موجبرهای جفت شده، ظاهر می گردد، ضروری است، زیرا سالیتون های گسسته از خنثی شدن پراش گسسته در این سیستم ها بوسیله عوامل غیرخطی بوجود می آیند. گسستگی سیستم عامل...

Dynamics of Rolling Disk

In the paper we present the qualitative analysis of rolling motion without slipping of a homogeneous round disk on a horisontal plane. The problem was studied by S. A. Chaplygin, P. Appel and D. Korteweg who showed its integrability. The behavior of the point of contact on a plane is investigated and conditions under which its trajectory is finit are obtained. The bifurcation diagrams are const...

Like a 'rolling stone': quantitative analysis of the body movement and skeletal dynamics of the sponge Tethya wilhelma.

Although sponges (Porifera) are basal Metazoa without muscles and a central nervous system, they are able to locomote, which is generally correlated to drastic morphological changes. This behaviour has been known for more almost 150 years, but it is only partly understood. The sponge T. wilhelma displays extraordinary movement and rhythmic body contractions, and is thus a valuable model for the...