109 research outputs found
Towards uncovering the charge carriers in tribocharging
No full textWenn sich zwei elektrisch neutrale Objekte berühren, kann dies zu einem Ladungsaustausch führen. Dieses Phänomen nennt sich triboelektrischer Effekt oder “tribocharging”. Obwohl dieser Prozess bereits seit über 2000 Jahren bekannt ist, sind viele Aspekte davon bis heute zu großen Teilen ungeklärt. Allen voran ist hierbei die Frage nach der Identität der Ladungsträger, welche für den Ladungsaustausch verantwortlich sind. Während oftmals Elektronen als wahrscheinlichste Ladungsträger gehandhabt werden, gibt es auch Thesen, in welchen Ionen für den Ladungstransport verantwortlich gemacht werden, da für beide Ansätze unterstützende experimentelle Ergebnisse vorliegen. Im Zuge dieser Arbeit wird deshalb ein Experiment entworfen, welches in weiterer Folge zum Ziel hat die Rolle von Ionen im triboelektrischen Effekt endgültig zu bestimmen. Dadurch, dass Ionen und Elektronen einen großen Massenunterschied aufweisen, wird ein Massenspektrometer verwendet. Die Idee des Experiments lautet wie folgt: Der triboelektrische Effekt wird verwendet, um zwei nichtleitende Proben aneinander elektrisch aufzuladen, danach wird eine der Proben nahe am Eingang eines Massenspektrometers erhitzt. Dieser Temperaturanstieg könnte zu Desorption von Ionen führen. Wenn die Anzahl der desorbierten Ionen mit der Gesamtladung der Probe korreliert, wäre die Existenz von ionischen Ladungsträgern im triboelektrischen Effekt unbestritten. Um aber dieses Experiment umsetzen zu können, müssen zuerst einige grundsätzliche Fragen geklärt werden, was schlussendlich den Inhalt dieser Diplomarbeit darstellt. Abgesehen vom generellen Aufbau des Experiments ist ein essenzieller Punkt die Notwendigkeit eines passenden Ladungsmessungsapparats, da Objekte vermessen werden müssen, ohne jemals mit ihnen in Kontakt zu kommen. Dafür wird ein Messsystem mit zwei individuellen Messpunkten entworfen, verbaut und auf dessen Kapazitäten getestet. Mit diesem System wird in weiterer Folge der triboelektrische Effekt bei verschiedenen Drücken charakterisiert, wobei besonderer Fokus auf das theoretische sowie experimentelle Entladungsverhalten gelegt wird. Schlussendlich wird thematisiert, ob thermische Desorption von Ionen prinzipiell möglich ist. Dabei werden experimentell erhobene Daten präsentiert, welche die Machbarkeit jener Desorption nahelegen.If two electrically neutral materials are brought into contact, an exchange of charge can occur. This effect, called tribocharging, has been known for over 2000 years, yet its mechanism is still poorly understood. Perhaps one of the most puzzling questions is the identity of the charge-carrier itself. While it is often assumed that the carriers are electrons, they could also be ions, and different experiments in different circumstances provide suggestive evidence for both cases. In order to address this fundamental issue, we develop an experiment with the end goal to undoubtedly determine the role of ionic charge transfer in insulator contact charging. Since ions are best differentiated from electrons by their huge mass difference, a mass spectrometer is utilized. The experiment is planned as follows: An insulating sample is charged up via contact with another sample before facing the entrance of a mass spectrometer. Afterwards the sample’s temperature is increased, which could lead to thermal ionic desorption. If the amount of thermally desorbing ions can be correlated to the total charge exchange, the existence of ionic charge carriers in contact charging would be undisputed. In order to arrive at this stage of the experiment, a number of unresolved issues have to be addressed first, representing the subject of this thesis. Apart from setting up the experiment in general, the first primary task is given by the need of a suitable contact-less charge measurement system. For this, a system is designed, built and tested for its capabilities. Two separate measurement points are in place in order to ensure the charge exchange is accurately tracked. Said system is then utilized to characterise the behaviour of contact charging at different pressure levels, putting special focus on the theoretical as well as the experimental discharging behaviour. Lastly, the feasibility of thermal ionic desorption in general is discussed, including preliminary experiments that support the idea of said desorption
After the goldrush : Joe Felber, Sasha Grbich, Lisa Harms
No full textCatalogue of an exhibition held at SASA Gallery, Adelaide, 5 May-5 June 2009.Artist: Lisa Harms.
Editor: Mary Knights.
Includes bibliographical references
Central nervous system and muscular bundles preserved in a 240 million year old giant bristletail (Archaeognatha: Machilidae)
No full textAmong the incomparably diverse group of insects no cases of central nervous system (CNS) preservation have been so far described in compression fossils. A third of the fossil insects collected from a 240-239 million year old (Ma) level at Monte San Giorgio UNESCO World Heritage (Switzerland-Italy) underwent phosphatization, resulting in the extraordinary preservation of soft tissues. Here we describe Gigamachilis triassicus gen. et sp. nov. (Archaeognatha: Machiloidea: Machilidae) that, with an estimated total length of ∼80 millimeters, represents the largest apterygote insect ever recorded. The holotype preserves: (i) components of the CNS represented by four abdominal ganglia, optic lobes with neuropils and compound retina; (ii) muscular bundles. Moreover, G. triassicus, possessing morphological features that prompt its assignment to the extant archaeognathan ingroup Machilidae, places the origin of modern lineages to Middle Triassic. Interestingly, at Monte San Giorgio, in the same stratigraphic unit the modern morphology of G. triassicus co-occurs with the ancient one represented by Dasyleptus triassicus (Archaeognatha: †Monura). Comparing these two types of body organization we provide a new reconstruction of the possible character evolution leading towards modern archaeognathan forms, suggesting the acquisition of novel features in a lineage of apterygote insects during the Permian or the Lower Triassic
Towards identifying the charge carriers in tribocharging (seminar talk)
No full textIf two electrically neutral materials are brought into contact, an exchange of charge can occur. This effect is called tribocharging and has been known for over 2500 years, yet it is still poorly understood. Perhaps the most important unresolved issue is the unknown identity of the charge-carrier itself. While it is often assumed that the carriers are electrons, they could also be ions, and different experiments in different circumstances provide suggestive evidence for both cases. In order to address this fundamental issue, an experiment whose aim is to clearly identify the carrier responsible for tribocharging is being built.
For this, tribocharging experiments with insulating samples in vacuum are being carried out. After contact and charge exchange, we heat one sample near the entrance to a single-charge sensitive quadrupole mass spectrometer (QMS), which can measure ionic charges leaving the sample in real time and with single ion sensitivity. Simultaneously, a charge measurement with a Faraday cup is used to cross check the QMS measurement. If the charge leaving the sample corresponds to the amount of ions detected by the QMS, the ions in question can be identified. In the case of no particle detection a charge exchange through electrons is strongly suggested
Transcultural communication as an ethical challenge in the health sector : current problems and innovative solutions
No full textMigrant/innen erhalten tendenziell eine schlechtere Gesundheitsversorgung als Menschen ohne Migrationshintergrund. Einer der Hauptgründe dafür liegt in der Sprachbarriere. Der Status Quo bei der Überwindung dieser Barriere stellt in Österreich vorwiegend die kurzfristige Beiziehung von Laiendolmetscher/innen, das Kommunizieren „mit Händen und Füßen“ und das Verwenden übersetzter Informationsmaterialien dar. Daraus entstehen Belastungen für Patient/innen und Mitarbeitende im Gesundheitswesen, die auf Basis der Forschungsliteratur gesammelt und diskutiert werden. Teilweise stehen Krankenhäusern Telefon- und Videodolmetschdienste zur Verfügung.Diese Masterarbeit geht der Frage nach, welche professionellen, transkulturellen Kommunikationsmaßnahmen im intramuralen Gesundheitswesen notwendig sind und durch welche rechtlichen Normen und ethische Argumente sich diese begründen lassen. Dafür werden österreichische und steirische Rechtsdokumente herangezogen. In weiterer Folge wird die ethische Dimension anhand der Menschenrechte, der bioethischen Prinzipien nach Beauchamp und Childress und des Genfer Gelöbnisses diskutiert. Sowohl aus den Erkenntnissen aus den rechtlichen Normen als auch aus den ethischen Argumenten werden Kriterien für eine gelingende transkulturelle Kommunikation abgeleitet. Diese Kriterien bilden die Basis für eine Beurteilung des Status Quo der Dolmetschlösungen in Österreich und der aktuellen technischen Innovationen, beispielsweise Dolmetschsoftware. Basierend auf den Ergebnissen der vorliegenden Masterarbeit fordert die Autorin diskriminierungsfreie Kommunikationsmöglichkeiten für alle Patient/innen, konkreter die selbstverständliche Beiziehung professioneller Dolmetscher/innen und/oder die Entwicklung von technischen Dolmetschmöglichkeiten speziell für das Gesundheitswesen unter Einhaltung strenger Datenschutzvorgaben.Migrants often receive poorer health care than people without a migration background. One of the main reasons is the language barrier. At the moment in Austria this barrier is often overcome by using amateur interpreters, by communicating through gestures and by using translated information. These practices put a strain on patients as well as healthcare workers, which is being discussed based on research literature. Some hospitals already have the opportunity to use telephone interpreting or video remote interpreting. This master thesis provides answers to the question of necessity for transcultural communication measures in the health care sector and if so, on which legal and ethical norms it is based on. Austrian and Styrian law offer one basis for this necessity, the other one being ethical dimensions such as human rights, The Principles of Biomedical Ethics (developed by Beauchamp and Childress) and The Declaration of Geneva and their respective arguments. These laws and theories are being compared and discussed using relevant literature. The author derives her own criteria for successful transcultural communication from the previously outlined legal and ethical dimensions. The status quo of interpreting in Austria as well as technological innovations for example interpreting software are judged by applying these criteria. As a conclusion to her findings the author demands communication measures for all patients in intramural healthcare, without any discrimination. Specifically, there is a need for professional interpreters and/or the development of technological interpreting measures that are especially fit for the healthcare sector and fulfill high data protection standards.Anna Felber, BAZusammenfassungen in Deutsch und EnglischAbweichender Titel laut Übersetzung des Verfassers/der VerfasserinMasterarbeit Karl-Franzens-Universität Graz 2020 D1146
Forms and functions of multilingualism in the work of Carmine Abate
No full textElisa Maria Felber: FORMEN UND FUNKTIONEN DER MEHRSPRACHIGKEIT IM WERK CARMINE ABATESCarmine Abate, der als Angehöriger einer albanischen Minderheit in Kalabrien aufwuchs, später nach Deutschland emigrierte und heute im Trentino lebt, positioniert sich als Grenzgänger zwischen verschiedenen Sprachen und Kulturen. Die vorliegende Masterarbeit untersucht, auf welche Art und Weise die lebensweltliche Mehrsprachigkeit des Autors in seine literarischen Prosa- und Lyrikwerke einfließt, in denen er sowohl textübergreifend als auch textimmanent zwischen den Idiomen Italienisch, Arbëresh (einer archaischen Varietät des Albanischen), Deutsch und dem kalabresischen Dialekt wechselt. Anhand der ausgewählten Romane "Il mosaico del tempo grande" (2006), "La festa del ritorno" (2004), "La moto di Scanderbeg" (1999), "Il ballo tondo" (1991), der Erzählsammlung "Il muro dei muri" (1993) und dem Gedichtband "Terre di andata" (1996) werden die darin enthaltenen multilingualen Elemente hinsichtlich ihres formalen Charakters und insbesondere ihrer Funktionalität, das heißt Zweck und Wirkung ihrer literarischen Verwendung, untersucht. Unter Behandlung bestehender Funktionstypologien (insbesondere jener von András Horn, Tatiana Bisanti und Elke Sturm-Trigonakis) wird dabei ein Modell entworfen, das speziell auf das Werk Carmine Abates anwendbar ist und das die folgenden Schwerpunkte erkennen lässt: Während die Mehrsprachigkeit in der Prosa in erster Linie einer realistischen, authentischen Darstellungsweise dient, erfüllt sie in der Lyrik vorwiegend ludisch-experimentelle Funktion. Dabei modelliert die Sprachmischung allgemein jene Themen, die für die Gattung der Migrations- bzw. Minderheitenliteratur (der die Texte Abates zugerechnet werden) typisch sind: Sie erfüllt den Zweck, das Fremde und das Eigene zu markieren, die Koexistenz bzw. den Konflikt zwischen den Sprachen und Kulturen anzuzeigen und die multiple Identität der Figuren sowie des Autors darzustellen.Elisa Maria FelberFORMS AND FUNCTIONS OF MULTILINGUALISMIN THE WORK OF CARMINE ABATECarmine Abate, who grew up in an Italo-Albanian community in Calabria and emigrated to Germany at a young age, living in Trentino today, represents the restless wanderer between different languages and cultures. The thesis at hand investigates the relationship between the author?s multilingual life-experience and his literary work, where he switches between the different idioms: Italian, Arbëresh (an archaic variety of Albanian), German and the Calabrian dialect. On the basis of the selected novels, "Il mosaico del tempo grande" (2006), "La festa del ritorno" (2004), "La moto di Scanderbeg" (1999), "Il ballo tondo" (1991), the short story collection "Il muro dei muri" (1993) and the poetry collection "Terre di andata" (1996), it is the principal aim of this paper to examine the multilingual elements in terms of their formal character and in particular their functionality, i.e. the specific purpose and effect of their literary use. The thesis takes into account different typologies (especially those of András Horn, Tatiana Bisanti and Elke Sturm-Trigonakis) and develops a function model which can be in particular applied to the work of Abate. Basically, it shows that the use of multilingual interferences contributes to a mimetic mode of representation in the narrative genres, whereas in lyricism, it primarily fulfills a ludic experimental function. Generally, the mixture of different languages represents the typical issues of migration or minority literature (the genre Abates works are assigned to): its aim is to mark ?the Self and the Other?, to indicate the coexistence or the conflict between different languages and cultures and to symbolize the multiple identity of the characters as well as of the author.vorgelegt von Elisa Maria FelberAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersGraz, Univ., Masterarb., 2010Text dt., teilw. ital. - Zsfassung dt. und ital
Quaternary refugia of the sweet chestnut (Castanea sativa Mill.): an extended palynological approach
No full textKnowledge about the glacial refugia of the thermophilous European Castanea sativa Mill. (sweet chestnut) is still inadequate. Its original range of distribution has been masked by strong human impact. Moreover, under natural conditions the species was probably admixed with other taxa (such as Quercus, Fraxinus, Fagus, Tilia) and thus possibly represented by low percentages in pollen records. In this paper we try to overcome the difficulties related to the scarcity and irregularity of chestnut pollen records by considering 1471 sites and extending the palynological approach to develop a Castanea refugium probability index (IRP), aimed at detecting possible chestnut refugia where chestnuts survived during the last glaciation. The results are in close agreement with the current literature on the refugia of other thermophilous European trees. The few divergences are most probably due to the large amount of new data integrated in this study, rather than to fundamental disagreements about data and data interpretation. The main chestnut refugia are located in the Transcaucasian region, north-western Anatolia, the hinterland of the Tyrrhenian coast from Liguria to Lazio along the Apennine range, the region around Lago di Monticchio (Monte Vulture) in southern Italy, and the Cantabrian coast on the Iberian peninsula. Despite the high likelihood of Castanea refugia in the Balkan Peninsula and north-eastern Italy (Colli Euganei, Monti Berici, Emilia-Romagna) as suggested by the IRP, additional palaeobotanical investigations are needed to assess whether these regions effectively sheltered chestnut during the last glaciation. Other regions, such as the Isère Département in France, the region across north-west Portugal and Galicia, and the hilly region along the Mediterranean coast of Syria and Lebanon were classified as areas of medium refugium probability. Our results reveal an unexpected spatial richness of potential Castanea refugia. It is likely that other European trees had similar distribution ranges during the last glaciation. It is thus conceivable that shelter zones with favourable microclimates were probably more numerous and more widely dispersed across Europe than so far assumed. In the future, more attention should be paid to pollen traces of sporadic taxa thought to have disappeared from a given area during the last glacial and post-glacial period
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