Self-healing in epoxy thermoset polymer films triggered by UV light

Self-healing of damaged structures can occur in three processes: capsule-based healing, vascular healing and intrinsic healing of polymers. The latest concept has a tremendous potential to repair damaged polymers and composite structures. Until now self-healing of composite materials has been addressed using capsule based resin with an initiator that polymerises in the damaged region. In this study, self-healing behaviour of cured epoxy thermoset resins modified with an epoxy-functionalised photoresponsive azobenzene molecule has been addressed by UV light without the use of any resin capsules or other component that is not chemically joined with the composites. The study was executed by nanoindentation and atomic force microscopy (AFM). Artificially damaged thermoset films exhibited good self-healing behaviour under UV irradiation only. This effect is attributed to the intrinsic healing mechanism triggered by UV-induced trans→cis isomerization of the azobenzene chromophore which enables the damaged polymeric matrix to recover.Funded by Defence Science and Technology Laboratory (DSTL

Sample path large deviations for Laplacian models in (1+1)(1+1)-dimensions

For Laplacian models in dimension $(1+1)$ we derive sample path large deviations for the profile height function, that is, we study scaling limits of Gaussian integrated random walks and Gaussian integrated random walk bridges perturbed by an attractive force towards the zero-level, called pinning. We study in particular the regime when the rate functions of the corresponding large deviation principles admit more than one minimiser, in our models either two, three, or five minimiser depending on the pinning strength and the boundary conditions. This study complements corresponding large deviation results for gradient systems with pinning for Gaussian random walk bridges in $(1+1)$-dimension (\cite{FS04}) and in $(1+d)$-dimension (\cite{BFO}), and recently in higher dimensions in \cite{BCF}. In particular it turns out that the Laplacian cases, i.e., integrated random walks, show richer and more complex structures of the minimiser of the rate functions which are linked to different phases.Comment: 37, 5 figure

Human-display interactions: Context-specific biases

Recent developments in computer engineering have greatly enhanced the capabilities of display technology. As displays are no longer limited to simple alphanumeric output, they can present a wide variety of graphic information, using either static or dynamic presentation modes. At the same time that interface designers exploit the increased capabilities of these displays, they must be aware of the inherent limitation of these displays. Generally, these limitations can be divided into those that reflect limitations of the medium (e.g., reducing three-dimensional representations onto a two-dimensional projection) and those reflecting the perceptual and conceptual biases of the operator. The advantages and limitations of static and dynamic graphic displays are considered. Rather than enter into the discussion of whether dynamic or static displays are superior, general advantages and limitations are explored which are contextually specific to each type of display

Exploring Higher Order Thinking Strategies in Georgia\u27s Top Performing Middle Schools

Developmental psychologists defined adolescent cognitive development as a period of time when individuals learn to mentally separate from adults and establish a self‑sufficient identity capable of the autonomous thought necessary to apply higher-order thinking. In contrast, college professors of the millennial generation stated that students demonstrate increased immaturity levels inconsistent with those of prior generations. Hence, the focus of this study was to examine the higher-order thinking strategies that teachers of adolescents have implemented within the five top performing middle schools in the state of Georgia. The findings offered a potential coexistence of higher-order thinking abilities and autonomous behavior and suggested that a better fluency in higher-order thinking could supply students with the critical thinking and autonomous problem-solving skills required to succeed in future endeavors

Interactive Visualization Lenses:: Natural Magic Lens Interaction for Graph Visualization

Information visualization is an important research field concerned with making sense and inferring knowledge from data collections. Graph visualizations are specific techniques for data representation relevant in diverse application domains among them biology, software-engineering, and business finance. These data visualizations benefit from the display space provided by novel interactive large display environments. However, these environments also cause new challenges and result in new requirements regarding the need for interaction beyond the desktop and according redesign of analysis tools. This thesis focuses on interactive magic lenses, specialized locally applied tools that temporarily manipulate the visualization. These may include magnification of focus regions but also more graph-specific functions such as pulling in neighboring nodes or locally reducing edge clutter. Up to now, these lenses have mostly been used as single-user, single-purpose tools operated by mouse and keyboard. This dissertation presents the extension of magic lenses both in terms of function as well as interaction for large vertical displays. In particular, this thesis contributes several natural interaction designs with magic lenses for the exploration of graph data in node-link visualizations using diverse interaction modalities. This development incorporates flexible switches between lens functions, adjustment of individual lens properties and function parameters, as well as the combination of lenses. It proposes interaction techniques for fluent multi-touch manipulation of lenses, controlling lenses using mobile devices in front of large displays, and a novel concept of body-controlled magic lenses. Functional extensions in addition to these interaction techniques convert the lenses to user-configurable, personal territories with use of alternative interaction styles. To create the foundation for this extension, the dissertation incorporates a comprehensive design space of magic lenses, their function, parameters, and interactions. Additionally, it provides a discussion on increased embodiment in tool and controller design, contributing insights into user position and movement in front of large vertical displays as a result of empirical investigations and evaluations.Informationsvisualisierung ist ein wichtiges Forschungsfeld, das das Analysieren von Daten unterstützt. Graph-Visualisierungen sind dabei eine spezielle Variante der Datenrepräsentation, deren Nutzen in vielerlei Anwendungsfällen zum Einsatz kommt, u.a. in der Biologie, Softwareentwicklung und Finanzwirtschaft. Diese Datendarstellungen profitieren besonders von großen Displays in neuen Displayumgebungen. Jedoch bringen diese Umgebungen auch neue Herausforderungen mit sich und stellen Anforderungen an Nutzerschnittstellen jenseits der traditionellen Ansätze, die dadurch auch Anpassungen von Analysewerkzeugen erfordern. Diese Dissertation befasst sich mit interaktiven „Magischen Linsen“, spezielle lokal-angewandte Werkzeuge, die temporär die Visualisierung zur Analyse manipulieren. Dabei existieren zum Beispiel Vergrößerungslinsen, aber auch Graph-spezifische Manipulationen, wie das Anziehen von Nachbarknoten oder das Reduzieren von Kantenüberlappungen im lokalen Bereich. Bisher wurden diese Linsen vor allem als Werkzeug für einzelne Nutzer mit sehr spezialisiertem Effekt eingesetzt und per Maus und Tastatur bedient. Die vorliegende Doktorarbeit präsentiert die Erweiterung dieser magischen Linsen, sowohl in Bezug auf die Funktionalität als auch für die Interaktion an großen, vertikalen Displays. Insbesondere trägt diese Dissertation dazu bei, die Exploration von Graphen mit magischen Linsen durch natürliche Interaktion mit unterschiedlichen Modalitäten zu unterstützen. Dabei werden flexible Änderungen der Linsenfunktion, Anpassungen von individuellen Linseneigenschaften und Funktionsparametern, sowie die Kombination unterschiedlicher Linsen ermöglicht. Es werden Interaktionstechniken für die natürliche Manipulation der Linsen durch Multitouch-Interaktion, sowie das Kontrollieren von Linsen durch Mobilgeräte vor einer Displaywand vorgestellt. Außerdem wurde ein neuartiges Konzept körpergesteuerter magischer Linsen entwickelt. Funktionale Erweiterungen in Kombination mit diesen Interaktionskonzepten machen die Linse zu einem vom Nutzer einstellbaren, persönlichen Arbeitsbereich, der zudem alternative Interaktionsstile erlaubt. Als Grundlage für diese Erweiterungen stellt die Dissertation eine umfangreiche analytische Kategorisierung bisheriger Forschungsarbeiten zu magischen Linsen vor, in der Funktionen, Parameter und Interaktion mit Linsen eingeordnet werden. Zusätzlich macht die Arbeit Vor- und Nachteile körpernaher Interaktion für Werkzeuge bzw. ihre Steuerung zum Thema und diskutiert dabei Nutzerposition und -bewegung an großen Displaywänden belegt durch empirische Nutzerstudien

The stability and assembly of sterically stabilized non-polar nanoparticles

Sterically stabilized, non-polar nanoparticles find already first applications beyond research. Predictions how such particles behave in different medias are difficult. To get a better understanding of the physical and chemical connections between core, ligand, and solvent, two fields were investigated in this dissertation: The stability of non-polar nanoparticles at different temperatures and the controlled assembly during confinement. It was shown, that the stability of sterically stabilized nanoparticles depends on core-diameter, ligand, and solvent. The temperature induced assembly of the nanoparticles showed two different areas: Ligand-dominated and core-dominated. The non-linear transition is thereby a function of the core-diameter and the ligand length. With the help of emulsion, it was possible to produced binary supraparticles from binary nanoparticle dispersions. By varying the pressure during the production process binary supraparticles with three different structures were produced: Crystalline, Janus, and core-shell. The pressure was either applied by the surfactant (Laplace-pressure) or externally. In-situ measurements with small angle X-ray scattering shown, that the pressure influences the dispersity of the nanoparticles.Sterisch stabilisierte, unpolare Nanopartikel finden bereits erste Anwendungen außerhalb der Forschung. Vorhersagen, wie sich solche Partikel in verschiedenen Medien verhalten, fällt dabei schwer. Um die physikalischen und chemischen Zusammenhänge zwischen den Kernen, Liganden und Lösemittel besser zu verstehen, wurden in dieser Dissertation zwei Gebiete untersucht: Die Stabilität von unpolaren Nanopartikeln bei verschiedenen Temperaturen und die kontrollierte Anordnung bei räumlicher Restriktion. Es konnte gezeigt werden, dass die Stabilität von sterisch stabilisierten Nanopartikeln abhängig vom Kerndurchmesser, Ligand und Lösemittel ist. Die temperaturinduzierte Anordnung von den Nanopartikeln hat zwei Bereiche aufgezeigt: Liganden-dominiert und Kern-dominiert. Der nichtlineare Übergang hängt dabei vom Durchmesser des Kerns und von der Länge des Liganden ab. Mit der Hilfe von Emulsionen konnten binäre Suprapartikel aus binären Nanopartikel Dispersionen herstellt werden. Durch die Variation vom Druck während des Herstellungsprozesses konnten binäre Suprapartikel mit drei verschiedenen Strukturen hergestellt werden: Kristallin, Janus und Kern-Hülle. Der Druck konnte dabei entweder durch das Tensid (Laplace-Druck) oder extern angewendet werden. In-situ Messungen mittels Kleinwinkel-Röntgenstreuung haben gezeigt, dass der Druck die Dispersität der Nanopartikel beeinflusst

Efektywność szpitala publicznego – rozważania o istocie i problemach badawczych

Stakeholders of public hospitals are primarily interested in the outcome of treatments, but the manager of the organization, the hospital management body, contractors, financial institutions, employees and controlling institutions expect information collection consisting of fiancial and non-fiancial data. The processed data become useful information for, among other uses, analysing the level of patient satisfaction, basic economic indicators and the effects of treatment and remaining activities. The data are also useful in assessing the performance of tasks by a public hospital. All information enables a comprehensive assessment of the entity’s activities, and therefore an assessment of its effectiveness, which means that the organization can apply a holistic approach to measuring the results of medical and other activities. The aim of the article was to present the essence, types and research problems of the efficiency of a public hospital. One of the research methods used in the paper was the critical literature review. The article describes the concept of effectiveness and indicates its types. The results of the research provide answers to research questions concerning: the scope of measurement of hospital performance, the types of efficiency and efficiency research.</>Interesariusze szpitali publicznych są zainteresowani przede wszystkim wynikami leczenia, ale kierownik organizacji, organ zarządzający szpitalem, kontrahenci, instytucje fiansowe, pracownicy i instytucje kontrolne oczekują zbiorów informacji obejmujących dane fiansowe i niefiansowe. Przetworzone dane stają się użytecznymi informacjami, wykorzystywanymi m.in. do analizy poziomu zadowolenia pacjentów, podstawowych wskaźników ekonomicznych oraz efektów leczenia i pozostałych działań. Dane są przydatne również w ocenie wykonywania zadań przez szpital publiczny. Wszystkie informacje umożliwiają kompleksową ocenę działalności jednostki, a tym samym ocenę jej skuteczności, co oznacza, że organizacja może zastosować holistyczne podejście do pomiaru wyników działań medycznych i innych. Celem artykułu było przedstawienie istoty, rodzajów i problemów badawczych efektywności publicznego szpitala. Do jego osiągnięcia wykorzystano krytyczny przegląd literatury. W opracowaniu opisano także koncepcję efektywności i wskazano jej typy. Wyniki badań dostarczyły odpowiedzi na pytania badawcze dotyczące: zakresu pomiaru efektywności szpitala, rodzajów efektywności oraz badań nad efektywnością

Mapping Tasks to Interactions for Graph Exploration and Graph Editing on Interactive Surfaces

Graph exploration and editing are still mostly considered independently and systems to work with are not designed for todays interactive surfaces like smartphones, tablets or tabletops. When developing a system for those modern devices that supports both graph exploration and graph editing, it is necessary to 1) identify what basic tasks need to be supported, 2) what interactions can be used, and 3) how to map these tasks and interactions. This technical report provides a list of basic interaction tasks for graph exploration and editing as a result of an extensive system review. Moreover, different interaction modalities of interactive surfaces are reviewed according to their interaction vocabulary and further degrees of freedom that can be used to make interactions distinguishable are discussed. Beyond the scope of graph exploration and editing, we provide an approach for finding and evaluating a mapping from tasks to interactions, that is generally applicable. Thus, this work acts as a guideline for developing a system for graph exploration and editing that is specifically designed for interactive surfaces.Comment: 21 pages, minor corrections (typos etc.

The Most Severe Test for Hydrophobicity Scales: Two Proteins with 88% Sequence Identity but Different Structure and Function

Protein-protein interactions (protein functionalities) are mediated by water, which compacts individual proteins and promotes close and temporarily stable large-area protein-protein interfaces. In their classic paper Kyte and Doolittle (KD) concluded that the "simplicity and graphic nature of hydrophobicity scales make them very useful tools for the evaluation of protein structures". In practice, however, attempts to develop hydrophobicity scales (for example, compatible with classical force fields (CFF) in calculating the energetics of protein folding) have encountered many difficulties. Here we suggest an entirely different approach, based on the idea that proteins are self-organized networks, subject to finite-scale criticality (like some network glasses). We test this proposal against two small proteins that are delicately balanced between alpha and alpha/beta structures, with different functions encoded with only 12% of their amino acids. This example explains why protein structure prediction is so challenging, and it provides a severe test for the accuracy and content of hydrophobicity scales. The new method confirms KD's evaluation, and at the same time suggests that protein structure, dynamics and function can be best discussed without using CFF