Wear Behavior of MoS2 Lubricant Layers during Sheet Metal Forming

The increased use of high and ultra-high strength steel and materials with a high adhesion tendency leads to higher demands regarding the wear resistance of forming tools. A promising approach addressing both challenges is to apply MoS2 dry film lubricant coating systems to the tool surface. These coatings reduce friction and the use of drawing oils and can also be used as an abherent. Once these coatings are exhausted, they can be chemically removed and reapplied. However, the tool life of the coatings cannot be predicted properly, due to their inhomogeneous wear behavior which depends on the forming parameters and differs locally. Moreover, there are carryover effects of MoS2-particles to already ablated areas. Given the unpredictability of the wear of dry film lubricant coatings, it is not possible to plan the recoating cycles appropriately and thus, the potential of these coatings for commercial applications is limited. In this research, the wear behavior of MoS2-layers in deep drawing processes was investigated on a test stand with DP800+Z coil material which ensures realistic load conditions at the draw ring radius. Firstly, the wear pattern was determined and locally different contact pressures were recorded and assigned to respective wear areas. Due to bending effects of the sheet material, there are two major areas of wear on the draw ring radius. During wear tests, the wear-dependent coating thickness during wear initiation was determined by using 3D laser scanning microscopy and the friction force was evaluated. © 2017 The Authors.European Research Association for Sheet Metal Working (EFB)German Federation of Industrial Research Associations (AiF)Federal Ministry of Economic Affairs and Energy (BMWi

Was Guðmundr á Glasisvǫllum Irish?

This article tackles the question of a possible Irish origin for the Old Norse literary figure Guðmundr á Glasisvǫllum. The images of Guðmundr, his realm Glasisvellir, and the sometimes associated territory of Ódáinsakr fluctuate in various ways in the different saga narratives in which they occur. The variability of the Guðmundr á Glasisvǫllum narrative has caused scholars to debate its possible origin for over a century. The more widely supported notion is that a mythological compound around Guðmundr must have originated in Irish mythology and folklore rather than being an indigenous, Nordic construct. The present article aims to follow up on this discussion, comparing the original Old Norse source material and that found in Gesta Danorum to Irish accounts that might have influenced them. By highlighting the differences between the Guðmundr á Glasisvǫllum complex and the suggested Irish sources, the degree to which it seems likely the motif could actually have originated in Irish thought will be assessed. Norwegian folk tales about the magical island Utrøst will then be considered to highlight the possibility of a more local background for Guðmundr and his realm

Einstein's fluctuation formula. A historical overview

A historical overview is given on the basic results which appeared by the year 1926 concerning Einstein's fluctuation formula of black-body radiation, in the context of light-quanta and wave-particle duality. On the basis of the original publications (from Planck's derivation of the black-body spectrum and Einstein's introduction of the photons up to the results of Born, Heisenberg and Jordan on the quantization of a continuum) a comparative study is presented on the first line of thoughts that led to the concept of quanta. The nature of the particle-like fluctuations and the wave-like fluctuations are analysed by using several approaches. With the help of the classical probability theory, it is shown that the infinite divisibility of the Bose distribution leads to the new concept of classical poissonian photo-multiplets or to the binary photo-multiplets of fermionic character. As an application, Einstein's fluctuation formula is derived as a sum of fermion type fluctuations of the binary photo-multiplets.Comment: 34 page

Irreducible decomposition of Gaussian distributions and the spectrum of black-body radiation

It is shown that the energy of a mode of a classical chaotic field, following the continuous exponential distribution as a classical random variable, can be uniquely decomposed into a sum of its fractional part and of its integer part. The integer part is a discrete random variable (we call it Planck variable) whose distribution is just the Bose distribution yielding the Planck law of black-body radiation. The fractional part is the dark part (we call is dark variable) with a continuous distribution, which is, of course, not observed in the experiments. It is proved that the Bose distribution is infinitely divisible, and the irreducible decomposition of it is given. The Planck variable can be decomposed into an infinite sum of independent binary random variables representing the binary photons (more accurately photo-molecules or photo-multiplets) of energies 2^s*h*nu with s=0,1,2... . These binary photons follow the Fermi statistics. Consequently, the black-body radiation can be viewed as a mixture of statistically and thermodynamically independent fermion gases consisting of binary photons. The binary photons give a natural tool for the dyadic expansion of arbitrary (but not coherent) ordinary photon excitations. It is shown that the binary photons have wave-particle fluctuations of fermions. These fluctuations combine to give the wave-particle fluctuations of the original bosonic photons expressed by the Einstein fluctuation formula.Comment: 29 page

Victims in Restorative Justice at Post-sentencing level. A Manual

The content of this manual evolved from the research project ‘Restorative Justice at post-sentencing level; supporting and protecting victims’ carried out by an international European team from Belgium, Croatia, Germany, Portugal, Spain and the United Kingdom. This manual is one of several project publications. The target group of this manual consists of those who are, in the widest sense, related to the work with victims of crime but also those, who are interested in Restorative Justice. This manual describes how victims of crime and therewith offenders and the community can be supported in various different ways. Therefore, the awareness of their needs is central at the outset. Furthermore, it aims to provide understanding of the individual process of coping and may therefore also lead to more self-awareness. If the victim is interested and prepared, it is possible to carry out Restorative Justice procedures in all types of crime and at all levels of seriousness, as long as it fits the person’s needs. The different steps to gain understanding of the situation of a victim and to provide support, as well as to empower in order to deal with what has occurred, are described in this manual. The different phases, before, during and after a restorative process, will be outlined as well as various RJ-procedures, from indirect victim-offendermediation to conferencing and possible techniques to apply during these procedures. That an atmosphere of trust is essential during the whole process appears evident as it is a basic principle of all Restorative Justice procedures. In order to provide better orientation, each sub-section is initiated with a number of key issues, which are then elaborated in a short text and concluded with a precise recommendation for practitioners to apply in the work with victims. More experienced practitioners can use this manual as a book of reference and concentrate on the recommendation whereas those, who have had less contact with victims in their work, can use it as an additional guide. In the final section, some case studies from the project partners England, Schleswig-Holstein, Portugal and Croatia give an exemplary insight into the restorative work carried out, from the victim perspective only

„Postoperative Schwellung nach Knieendoprothetik– Einfluss einer Unterdruckanwendung (LymphaTouch®) im Vergleich zur manuellen Lymphdrainage – Eine randomisierte kontrollierte Studie“

Sekundäre Lymphödeme in der unteren Extremität nach der Implantation einer Knieendoprothese stellen in der postoperativen Rehabilitation eine Herausforderung beim Erreichen eines möglich schnellen Outcomes dar. Zur Reduzierung der Schwellung hat sich in der unmittelbar postoperativen Frühphase die manuelle Lymphdrainage, die Hochlagerung, das Kühlen und die Kompression bewährt. Ein neues apparatives Verfahren mittels Unterdrucktherapie, genannt LymphaTouch®, steht ebenfalls zur Behandlung von Lymphödemen zur Verfügung. Ziel der vorliegenden Studie ist über die Wirksamkeit von LymphaTouch® in der Behandlung des postoperativen Lymphödems nach Knieendoprothesenimplantation Aussagen treffen zu können. Dazu wurden in einer randomisierten nicht-verblindeten Studie 50 Patienten/Patientinnen in zwei Gruppen aufgeteilt. Die Kontrollgruppe erhielt täglich eine Behandlung mittels manueller Lymphdrainage, während in der Interventionsgruppe eine Therapie mittels apparativen Unterdrucks durchgeführt wurde. Das Ziel war festzustellen, ob die Anwendung von LymphaTouch® vergleichbare Ergebnisse zur manuellen Lymphdrainage in Bezug auf die Reduktion des Umfangs, der Mobilität des Kniegelenks sowie zu einer Verringerung der Krankenhausaufenthaltsdauer und der postoperativen Schmerzen liefert. In der LymphaTouch®-Gruppe konnte ein signifikant besseres Ergebnis in der Schmerzreduktion bereits ab dem zweiten Tag nach der Operation beobachtet werden (p = 0,008). Auch in der Wiederherstellung der Funktion des Kniegelenks zeigte sich die LymphaTouch® -Gruppe überlegen. Während nach der Behandlung mit LymphaTouch® das präoperative Streckdefizit von 3,8° (SD 2,99) am 4. Tag postoperativ auf 2,2° (SD 3,25) sank, änderte sich der Wert durch die manuelle Lymphdrainage nur gering (präoperative Streckung MW = 3,88° SD 4,58, 4. postoperativer Tag MW = 4,4°, SD 3,63). Eine Zunahme der Schwellung war postoperativ zu verzeichnen und reduzierte sich in beiden Gruppen bis zum Entlassungstag vergleichbar. Es gab keine statistisch signifikanten Unterschiede. Die analgesierende Wirkung von LymphaTouch®, zu der es noch keine gesicherten Studien gibt, kann auf mehrere Mechanismen basieren. Durch die Reduzierung des Ödems erfolgt in den Gelenken eine Druckentlastung, was zu einer Linderung der Beschwerden führt [1]. Die Normalisierung des Säure-Basen-Haushaltes im Interstitium könnte sich genauso wie die Stimulierung der Mechanorezeptoren, die die Schmerzleitung hemmen, positiv auf die Linderung von Schmerzen auswirken [2]. Auch ein Einfluss auf das muskulär-faszialen System sollte weiter untersucht werden. Weitere Studien zur genauen Wirkung durch die LymphaTouch® Anwendung sind notwendig. Die abschwellende Wirkung der manuellen Lymphdrainage nach Knie-TEP-Implantation wurde in der Literatur kontrovers diskutiert. Die Vielfalt der Resultate ergibt sich aus der Tatsache, dass keine klaren Maßstäbe für die erforderliche Intensität bei der Durchführung der Behandlung existieren. Die subjektive Griffintensität und Druckstärke der einzelnen Physiotherapeuten kann variieren und führt zu wenig objektiven Druckverhältnissen auf das Gewebe. Ein zu kräftiger Druck zerstört Ankerfilamente und verursacht Muskelkrämpfe in den Lymphgefäßwänden, insbesondere in den aktiv pumpenden Kollektoren. Ein zu geringer Druck führt dagegen nicht zur Entstauung der Extremität. Durch geeignete Einstellungen kann das Druckverhältnis von LymphaTouch® unabhängig vom Therapeuten immer den jeweiligen Arealen angepasst und konstant gehalten werden. Die postoperative Behandlung kann so von einem standardisierten Behandlungsverlauf profitieren und die Qualität der entstauenden Maßnahmen in der postoperativen Rehabilitation verbessern. Aufgrund seiner kompakten Bauweise kann sich der Einsatzbereich von LymphaTouch® auch auf die anschließende Rehabilitation oder im häuslichen Umfeld erstrecken. Zukünftige Studien haben die Aufgabe, die Behandlungsabläufe mit LymphaTouch® je nach Indikation zu standardisieren. Dadurch wird die Anwendung von LymphaTouch® optimiert, um das volle Potenzial auszuschöpfen und gleichzeitig die Grenzen nicht zu überschreiten, um bestmögliche Ergebnisse zu erzielen

A review of Monte Carlo simulations of polymers with PERM

In this review, we describe applications of the pruned-enriched Rosenbluth method (PERM), a sequential Monte Carlo algorithm with resampling, to various problems in polymer physics. PERM produces samples according to any given prescribed weight distribution, by growing configurations step by step with controlled bias, and correcting "bad" configurations by "population control". The latter is implemented, in contrast to other population based algorithms like e.g. genetic algorithms, by depth-first recursion which avoids storing all members of the population at the same time in computer memory. The problems we discuss all concern single polymers (with one exception), but under various conditions: Homopolymers in good solvents and at the $\Theta$ point, semi-stiff polymers, polymers in confining geometries, stretched polymers undergoing a forced globule-linear transition, star polymers, bottle brushes, lattice animals as a model for randomly branched polymers, DNA melting, and finally -- as the only system at low temperatures, lattice heteropolymers as simple models for protein folding. PERM is for some of these problems the method of choice, but it can also fail. We discuss how to recognize when a result is reliable, and we discuss also some types of bias that can be crucial in guiding the growth into the right directions.Comment: 29 pages, 26 figures, to be published in J. Stat. Phys. (2011

Lost in Translation: Adapting Supernatural Concepts from Old French Chivalric Literature into the Old Norse riddarasǫgur

While the post-millennial research of Old Norse literature saw an increased interest in the study of translated riddarasǫgur, the scholarly focus in these studies rests, for the main part, on the effects of translation, the role and representation of women and the studies of emotion portrayed in the narratives. However, the effect of translation on supernatural concepts – especially of Old Norse concepts – has, so far, been left unaddressed. The present thesis, thus, aims to bridge this gap in scholarship by investigating how the Old Norse translations and adaptations of Old French chivalric works had an altering and long-lasting effect on the Old Norse mythological landscape. Indeed, the present research project hopes to establish the translated riddarasǫgur as a valued source for the study of the development of Old Norse supernatural concepts. By highlighting the influx of foreign Old French ideas and their impact on the Old Norse literature and mythology, this study aspires to present new approaches regarding the understanding of the development of Old Norse supernatural concepts as well as their subsequent changes. Bearing the human element in translation as well as medieval translation practices in mind, the present thesis investigates twelfth- and thirteenth century Old French courtly romances and associated material as well as the thirteenth- and fourteenth-century Old Norse translations, redactions and reworkings thereof. The supernatural motifs (specifically the álfar, dvergar, jǫtnar and different forms of magic and magic wielders) described in these narratives will be examined in detail. The thesis includes an article concerning each concept which studies the differences and similarities in the concept’s presentation and measures the potential long-term effects initiated by the said translations by investigating later fornaldarsǫgur, indigenous riddarasǫgur and Icelandic folk legends. The first paper contained in the present thesis concerns the use of the Old Norse supernatural concept of the álfar (sg. álfr) as a translation for the Old French term fées (sg. fée), while the second article investigates the usage of the word dvergar (sg. dvergr) as a translation for the Old French nains (sg. nain) in the investigated literary corpora. The penultimate article examines the utilisation of the concept of the Old Norse jǫtnar (sg. jǫtunn) as a translation for the Old French idea of the jaiants (sg. jaiant), and the fourth and final article investigates the different notions and manifestations of magic and magic wielders displayed in the investigated Old French sources as well as their respective Old Norse renditions. This research project hopes to open this particular field of research to the broader scientific community by laying down what may be seen as the first stepping-stone for a series of related studies.Rannsóknir fræðimanna á þýðingum riddarasagna hafa eflst til muna eftir aldamótin en hið sama gildir ekki um rannsóknir á sjálfum efniviðni sagnanna, svo sem hvernig birtingarmynd kvenna er sýnd gegnum tilfinningar þeirra í sögunum. Hingað til hefur lítið verið kannað hvort og þá hver áhrif þýðingar efnis um yfirnáttúrulega hluti og atburði sem snúa að norrænni trú hafa verið. Markmið þessarar ritgerðar er að sýna fram á áhrif fornra franskra riddarasagna á hugmyndaheim norrænna manna um umhverfi sitt og landlýsingu, auk þess að sýna fram á áreiðanleika riddarasagna að því er varðar hugmyndir norrænna manna um hið yfirnáttúrlega. Ritgerðin greinir slíkar hugmyndir í hinum forn-frönsku bókmenntum og skoðar áhrif þeirra og innblástur í norrænum bókmenntum og goðafræði og sýnir þannig hvernig skilningur manna á yfirnáttúrulegum atburðum hefur þróast í aldanna rás. Í ritgerðinni er athyglinni einkum beint að hinum norrænu þýðingum tólftu og þrettándu aldar ástarsagna fornfranskra bókmennta og skoðað sérstaklega hvaða hlutverki hinn mannlegi þáttur og þeirra tíma þýðingarhefðir gegna. Yfirnáttúrulegar verur, svo sem álfar, dvergar og jötnar, auk ýmissa galdrahugtaka, sem fram koma í þessum frásögnum eru teknar til ítarlegrar skoðunar, og fjallað er um hverja áðurnefnda tegund í sérstökum kafla. Með samanburði við seinni tíma fornaldarsögur, upprunalegar riddarasögur og íslenskar þjóðsögur eru þessar þýðingar skoðaðar í þeim tilgangi að greina áhrif á hin yfirnáttúrulegu fyrirbæri í þeim. Í fyrsta hluta þessarar ritgerðar er fjallað um álfa í norrænum heimildum og goðsögulega tengingu þeirra við forn-franska hugtakið fées (eint. fée), annar hlutinn fjallar um dverga og hliðstæða tengingu þeirra við fornfranska hugtakið nains (eint. nain) með bókmenntafræðilegri nálgun. Meginkafli ritgerðarinar fjallar á sama hátt um jötna og hlistæða tengingu þeirra við fornfranska hugtakið jaiants (eint. jaiant). Í síðasta kaflanum er svo fjallað um norrænar galdrahefðir og galdratrú með hliðsjón af birtingarmynd þeirra í fornfrönskum bókmenntum. Með ritgerð þessari vonast höfundur til að opna gátt inn á lítt kannað fræðasvið sem getur eflt og víkkað rannsóknarhugmyndir og -aðferðir fræðimanna í fornnorrænum rannsóknum. (Ingunn Ásdísardóttir þýddi.)Rannsóknarsjóður Háskóla Íslands/ The Doctoral Grant of the University of Iceland Research Fun

Competition and Increasing Returns to Scale: A Model of Bank Size

This study examines the causal effects of bank size on banks' survival, asset quality and leverage. Two forces drive these effects: increasing returns to scale derived from banks' expertise and competition. The first enables bigger banks to survive competition better, have higher asset quality and be more leveraged. It drives banks into a race for expansion. This race toughens competition between banks, which edges out small banks and may worsen all banks' asset quality. Consequently, the banking industry will be dominated by a small number of highly leveraged banks. In this study, financial intermediation arises endogenously and co‐exists with direct finance