From geometrical modelling to simulation of touch of textile products - open modelling issues

The touch of textile products is a complex process, depending on the interaction between the human finger and the textile product. The evaluation of the touch, or so named handle properties is complex process, requiring samples, testing humans or special testing devices. The numerical evaluation of the surface is until now not reported, because of the complexity of the textile products. This work presents the current state of the 3D modelling of textile products at yarn and fiber level and the required additional steps in order these models to get applicable for numerical simulation of the fabric touch. This work cover only the aspects related to the textile representation and do not include the modelling of the human finger as mechanical and receptor system during the interaction.Die Berührung und der Griffevaluation von Textilprodukten sind komplexe Prozesse, die von der Interaktion zwischen dem menschlichen Finger und dem Textilprodukt abhängig sind. Die Bewertung der 'Touch'- oder so genannten Griffeigenschaften ist ein komplexer Prozess, der Proben, Testpersonen oder spezielle Testgeräte erfordert. Die numerische Simulation der Oberflächenbeschaffenheiten ist aufgrund der Komplexität der textilen Produkte bisher nicht bekannt. Diese Arbeit stellt den aktuellen Stand der 3D-Modellierung von Textilprodukten auf Garn- und Faserebene und die erforderlichen zusätzlichen Schritte vor, damit diese Modelle für die numerische Simulation der Haptik von Textilien eingesetzt werden können. Es werden nur die Aspekte abgedeckt, die sich auf die Darstellung der Textilien beziehen und beinhaltet nicht die Modellierung des menschlichen Fingers als mechanisches und rezeptives System während der Interaktion

Botulinum Toxin - historical overview

Cases of food poisoning with botulinum toxin have been reported as far back as Roman times. Emperor Leo VI of Byzantium prohibited the manufacturing of blood sausages with a law due to cases attributed to poisoning with Atropa belladonna. It was later proven that atropine does not have the effects described in the cases during his reign. It was not until the 19th century that scientists began detailed studies of the rising number of cases in which the patients reported nausea, vomiting, relaxation of muscles and inability to breathe properly. Such “outbreaks” of cases were reported in southern Germany and Belgium in short succession, which led medical scientists to believe they were connected. The toxin was first identified by Justinus Kerner - a German medical officer in Wuertemberg, as “fatty acids” or “fat toxin”. He failed to point the source of the toxin, however, he recognized the potential for medical use. Later in the 19th century Emile Pierre van Ermengem, a Belgian scientist, successfully identified the source of the “fatty acids”. It was later called Botulinum toxin after the Latin word for sausages “botulus”. Since then this substance, produced by C. botulinum, has been studied in detail by scientists around the world and many uses have been found. It is utilized in the treatment of neurological conditions, posttraumatic conditions, muscle spasms, irregular sweating, chronic pain, skin wrinkles, etc. The military have found use for it as well - the potency of the toxin can be effectively used in closed environments

Numerical Simulation of Joining Ropes by Sewing Stitches

Braided structures are widely used in numerous contexts including everyday practice. In most cases, rope ends are knotted to form various types of loops or tie them to rigid body parts; however, knots take up space that may not be available in some application scenarios, thus making them unsuitable for certain purposes. Hence, this paper introduces first development steps of a method for the numerical simulation of rope ends connected by sewing stitches

Simulation of injection and capture of beam electrons in small-size betatrons by the method of macroparticles

The simulation problem of self-consistent dynamics of electron beam in small-size betatrons has been considered. The description of numerical model developed on the basis of macroparticle method is presented. The results of process modelling of electron injection and capture on the acceleration mode in betatrons with axially-symmetrical and asymmetrical magnetic field are shown. Optimal input injection parameters by beam current and energy (20...40 keV and 0,1...1,0 А) providing the maximum number of the capture electrons are defined. The techniques of increasing capture efficiency due to using variations of external magnetic field and additional energy selection of circuital decelerating EMF of the captured electrons are numerically studied. It allows an increase in capture coefficient from 4 to 7,4 % and capture at the acceleration up to 7,4·1010 electrons

Möglichkeiten der TexMind Software für die Generierung von textilen Strukturen für FEM Simulationen und CAD Anwendungen

Objekte der Simulation sind textile Strukturen - Geflechte, Maschenwaren und Gewebe. Diese können als Seile, tragende und deckende Strukturen in der Architektur, Bekleidung, im Medizinbereich usw. verwendet werden. TexMind Software beinhaltet mehrere Tools für die Generierung der Geometrie von textilen Strukturen und die Durchführung von einzelnen Berechnungen und Simulationen. Beispiele aus den Bereichen Flechten und Maschenware werden gezeigt. Neben den Vorteilen und der Möglichkeiten wird auch eine kritische Übersicht der offenen Punkte dargestellt. Möglichkeiten für Export zu FEM, CFD und CAD Software und solcher für Computer-Animationen werden demonstriert

Essays on Factor Investing

Factor Investing is becoming increasingly important for both practitioners and academics. This dissertation focuses on the implications of factor investing for the efficiency of financial markets, the underlying drivers of factor premiums, the way factor investing strategies are implemented, and the added value for the end investors. In the first chapter, we show that assets invested in factor strategies have grown exponentially over the recent years, but factor investing is still far from the mature state of passive investing. In the second chapter, we document abnormal price reaction around factor index rebalancing driven by the demand of index funds. In chapter three, we find that the return predictive power of the quality factor originates from its ability to predict future earnings growth. Finally, we show evidence that factor investing requires a long-term focus to efficiently harvest its premiums

PATTERN RELATED ISSUES IN THE MODELLING OF DEFORMED OVER SURFACE WARP KNITTED STRUCTURES WITH LONGER UNDERLAPS

The yarn level modelling of warp knitted structures is a complex process. For structures placed on the plane, it is well investigated and there are a few software solutions and papers reported. This paper considers the simulation of warp knitted structure, deformed in the 3D space. Especially the modelling of the areas of high curvature are detailed observed. Underlaps with longer lengths makes an unreal visualization for simulation results. Different pattern with different length of the underlaps are modelled with original algorithm developed by the authors. Modelling and visualization problems in the areas with long underlaps are discussed and possible solutions are proposed

Curvature change of moving bodies and its application for development of protective elements for protective clothing

When the human body moves, the body curvatures always change on the corresponding parts of the body. For ideal protective clothing, body curvatures during different movements have to be taken into account, as they influence the protection and the wearing comfort. For this reason, this study will focus on demonstrating methods to visually display such curvature changes. The changes are visually shown in different poses. The aim is to use this method to optimize protective elements on body parts with increased curvature changes. This would make protective clothing safer and more comfortable to wear

Apocynum venetum L. and Apocynum pictum Schrenk (Apocynaceae) as multi-functional and multi-service plant species in Central Asia: a review on biology, ecology, and utilization

During the second half of the 20th century cotton was strongly promoted along the rivers of Central Asia. The irrigation agriculture resulted in wide spread soil salinization and severe water shortages within the river systems. Most prominent example is the desiccation of the Aral Sea. The natural vegetation along the rivers of Central Asia is adapted to periods of water shortage, is very productive, and contains plant species with valuable utilization opportunities. We reviewed the literature about Apocynum venetumL. and A. pictum Schrenk, two plant species of those riparian ecosystems, which are used as fibre and medicinal plants. A. venetum and A. pictum yield fibres, which can be used as textiles, though the fibres best are blended with cotton and/or chemical fibres. Though, the fibre extraction process needs more research attention. Furthermore, the literature shows that Apocynum leafs are used to produce antihypertonic tea and medicine. Both species grow under the arid climate of Central Asia without irrigation, because they exploit groundwater. Furthermore, both species can withstand higher soil salinization levels than cotton. Both species can be used and provide an income to local people under conditions, which are unfavourable to grow crops under irrigation. Such conditions are unreliable water supply for irrigation systems and/or saline soils

Possibilities for qualitative evaluation of the protection area of protective clothing

Protective clothing, worn for example by police, ambulance and private security services, has the task of protecting against weapon attacks and is becoming increasingly important. International standards specify test methods to ensure the protective effects and classes, but the protective surfaces or the wearing comfort are not defined more detailed in the standards. In the study, a new measurement method is developed and presented for determining the percentage of protected body parts by a stab protective vest. After considering various approaches, the combination of scanned 3D/4D body data and appropriate processing turned out to be the most suitable. With the developed method, the projection of protective surfaces onto scanned bodies or avatars is possible. This study helps defining a key indicator of the protected areas and therefore makes different vest variants more comparable