Helical close packings of ideal ropes

Closely packed conformations of helices formed on the ideal rope are considered. The pitch versus radius relations which define a closely packed helix are determined. The relations stem from the turn-to-turn distance and curvature limiting conditions. Plots of the relations are shown to cross each other. The physical sense of the crossing point is discussed.Comment: 14 pages, 10 figure

The ideal trefoil knot

The most tight conformation of the trefoil knot found by the SONO algorithm is presented. Structure of the set of its self-contact points is analyzed.Comment: 11 pages, 8 figure

The effect of yarn hairiness on air drag in ring spinning

Air drag on yarn and package surfaces affects yarn tension, which in turn affects energy consumption and ends-down in ring spinning. This study investigated the effects of yarn hairiness on air drag in ring spinning. Theoretical models of skin friction coefficient on the surface of rotating yarn packages were developed. The predicted results were verified with experimental data obtained from cotton and wool yarns. The results show that hairiness increases the air drag by about one-quarter and one-third for the rotating cotton and wool yarn packages, respectively. In addition, yarn hairiness increases the air drag by about one-tenth on a ballooning cotton yarn.<br /

Eating Disorder Narratives: Personal Experiences of Anorexia and Bulimia

The following paper explores the ways in which we currently understand eating disorders, examining the current theory and literature as well as providing the stories of three women and one man with first-hand experience with eating disorders. Through the use of formal interviews, the paper focuses not only on the ways in which an eating disorder affects an individual’s life but also on the ways in which an individual’s life affects the manifestation of his or her eating disorder

Tight open knots

The most tight conformations of prime knots are found with the use of the SONO algorithm. Their curvature and torsion profiles are calculated. Symmetry of the knots is analysed. Connections with the physics of polymers are discussed.Comment: 11 pages, 8 figure

Clochard, Olivier Dir. MIGREUROP. Atlas des migrants en Europe : approches critiques des politiques migratoires

Depuis la médiatisation de la « crise migratoire » en Europe, les images et discours qui traitent des migrations prolifèrent. Dans la nébuleuse de ces multiples productions, les différentes éditions de l’Atlas des migrants en Europe incarnent désormais un repère incontournable pour qui souhaite décrypter les enjeux des migrations internationales. Loin des discours alarmants, des chiffres approximatifs et des catégories insaisissables, les contributeurs s’attèlent ici à remettre en perspective..