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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

FIELD-PROGRAMMABLE MICROFLUIDIC TEST PLATFORM FOR POINT-OF-CARE DIAGNOSTICS

2013 November 1900 (has links)
Early work in electrowetting on dielectric (EWOD) devices has demonstrated their great potential in microfluidics; however, further work is needed to integrate EWOD technology into a system deployable for point-of-care (POC) diagnostics. This research is aimed at providing enabling technologies that foster a development path of EWOD devices using a process similar to the development of application-specific integrated circuits (ASICs). A field-programmable lab-on-a-chip (FPLOC), which allows designers to electrically program the prefabricated chip into EWOD applications, was fabricated and demonstrated based on novel microelectrode dot array (MEDA) architecture. The MEDA architecture proposes a standard EWOD component called “microelectrode cell”, which can be dynamically configured into microfluidic components to perform microfluidic operations of the biochip. The FPLOC is the first EWOD biochip fabricated by the standard low-voltage complementary metal-oxide-semiconductor (CMOS) technology, which allows smooth on-chip integration of microfluidics and microelectronics. A total of 900 droplet detection electrical circuits were integrated into the chip and a real-time droplet location map could show shapes and locations of all droplets on the chip. The daisy-chained control structure of the MEDA architecture allowed individual control of 900 microelectrodes by only using three control pads. This control structure was also leveraged to add the built-in self-test (BIST), which was proven to be very useful in diagnosing the chip, of the FPLOC. The FPLOC successfully demonstrated seamless hierarchical field-programmability. Compared to conventional bottom-up and full-custom design approaches, the FPLOC brings microfluidic technology closer to POC diagnostics by providing biochip designers with CAD support at a level similar to that of the semiconductor industry, without the time-consuming and costly process of hardware design, testing, and maintenance.
2

An Experimental Study to Test the Relationship Between Learner Control and Locus of Control on e-Learning in a Corporate Context

Eschenmann, Travis Wade 24 July 2012 (has links)
Research has identified a relationship between instructional design and learner control, principally in face to face educational settings, where the selection of control types will have an impact on the learner. However, as Miltiadou and Savenye (2003) note, more research is required that will "shed light on which motivational constructs can be identified as predictors of success in an online environment." (p. 21). In both the corporate and academic arenas, there is a growing interest in online courses; however, there is a lack of sufficient studies on the effects of design criterion that can potentially heighten learner motivation and reduce attrition rates in online courses. Abdul-Rahman (1994) identified a similar concern with respect to dropout rates and suggested that "identifying factors that interact to affect students' completion or non-completion of a distance education course" (p. 9) would go a long way to arming administrators and distance educators with information and tools that will help reduce learner attrition in distance education. This experimental study will test the relationship between learner control and locus of control as measured by scores on an assessment administered to selected employees of the Automobile Associate of America (AAA) Mid-Atlantic. The independent variables will be learner control and locus of control. Locus of control will be defined by each learner's score on the Adult Nowicki-Strickland Locus of Control Scale. Three dependent variables will be measured including assessment score, number of minutes spent in the learning program and amount of content viewed in an online, asynchronous course. / Ph. D.
3

Calorimètres miniaturisés sur puce : Impact de la miniaturisation des dispositifs sur leur performance

Bourque-Viens, Alexandre January 2014 (has links)
Les technologies de type laboratoire sur puce (« lab on chip » LOC) mettent à profit la miniaturisation pour réaliser production, traitement, et analyse physico-chimiques sur un même substrat de petite taille avec comme résultat des dispositifs portables, plus rapides, demandant de plus petites quantités de réactifs, produits et opérés à plus faible coût. Les produits et les applications développés pour tirer profit de ces avantages ont le potentiel de transformer plusieurs secteurs comme ceux de la médecine et de la surveillance environnementale. Les mesures de calorimétrie revêtent un intérêt particulier pour l’intégration aux plateformes de type LOC notamment parce que la production de chaleur est un phénomène ubiquitaire. Or, cette intégration repose avant tout sur la capacité de produire des dispositifs miniaturisés suffisamment performants et compatibles avec la construction des plateformes LOC. La calorimétrie miniaturisée est un champ relativement peu développé même si, comme à l’échelle conventionnelle, elle permet d’obtenir des informations utiles pour la compréhension des phénomènes de transformations de la matière. Or, la calorimétrie miniaturisée fait face à un défi de taille. La taille réduite des échantillons résulte inévitablement en une diminution de la quantité de chaleur à mesurer. Possiblement pour faire face à cette limite, la grande majorité des calorimètres miniaturisés adopte une configuration planaire, car le positionnement du système cellule calorimétrique-échantillon sur membrane a pour effet de maximiser leur sensibilité. La configuration membranaire réduit la conduction thermique à travers le substrat ce qui, à puissance égale, résulte en davantage de signal. Cette configuration demande toutefois certains compromis. Elle pousse par exemple à construire les thermopiles à partir de films de plus en plus minces afin d’éviter d’annuler les gains. Or, des effets de « film mince », sont observés qui dégradent significativement les propriétés attendues des matériaux. Les gains apportés par la configuration membranaire peuvent aussi être annulés par la conduction thermique hors substrat qui est très sensible à la géométrie de la source de chaleur ainsi qu’aux conditions ambiantes. Ces deux phénomènes affectent significativement la sensibilité des calorimètres miniaturisés et peuvent résulter en une diminution de la précision des mesures. Dans le premier cas, on estime à 20-30% l’erreur évitée; dans le second cas, on estime à près de 30% l’erreur évitée. Les contributions présentées dans cette thèse proposent des moyens d’améliorer la précision des calorimètres miniaturisés, en renforçant la compréhension des compromis fondamentaux à négocier dans la conception de tels dispositifs et d’établir un « modèle » pour prédire avec une plus grande fidélité la performance de calorimètres miniaturisés à partir des paramètres de l’architecture. On peut donc plus précisément évaluer le potentiel de différents designs de calorimètres miniaturisés et explorer la manière de faire des calorimètres miniaturisés de bons candidats à l’intégration sur les plateformes LOC, que ce soit sur structure membranaire ou d’autres substrats.
4

FLIGHT TEST INSTRUMENTATION OF THE PUSH-PULL EFFECT ON A CF-18 AIRCRAFT

Caballero, Rubén 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / During high performance fighter aircraft manoeuvres, a fighter pilot may be exposed to a physiological phenomenon known as the “Push-Pull Effect” (reference (ref) [1]). This effect will alter the pilot’s homeostasis whereas blood flow to the brain will be increased during low negative normal acceleration (-Gz) and suddenly decreased during positive normal acceleration (+Gz). It has been hypothesized that this effect can lessen the Gtolerance of the human body thereby making the subject more susceptible to G induced Loss of Consciousness (G-LOC) (refs [2], [3] and [4]). G-LOC is not a desirable state for a pilot in a high performance aircraft such as a CF-18. To better understand and study the Push-Pull Effect on a fighter pilot, the Aerospace Engineering Test Establishment (AETE) and the Defence and Civil Institute of Environmental Medicine (DCIEM) produced an In-Flight Research (IFR) Program sponsored by the Canadian Forces (CF). The aim of this program was to measure the physiological response of relaxed test subjects, unprotected by a G-suit, when exposed to the Push-Pull manoeuvre in flight. This IFR would validate the centrifuge data and confirm that the Push-Pull Effect can occur in flight. This paper will present the instrumentation, design, telemetry system and installation methodology utilized to perform experimental physiological research on a high performance, ejection seat equipped fighter aircraft (CF-18). Also, preliminary results on the Push-Pull Effect, obtained through this IFR Program will be presented.
5

Experimental Investigations of Core-Loc Armour Units

Simpalean, Adrian Raul 25 January 2019 (has links)
In the present study, the influence of geometric scale, unit orientation (alternatively, flow direction), and the dimensionless Reynolds and Keulegan-Carpenter quantities on the hydrodynamic loading of Core-Loc armour units is explored through a series of physical modelling tests under unsteady and oscillatory flow conditions.
6

DESIGN AND CHARACTERIZATION OF PLANAR LOW REYNOLDS NUMBER MICROFLUIDIC MIXERS FOR LAB-ON-A-CHIP APPLICATIONS

BHAGAT, ALI ASGAR SALEEM 02 October 2006 (has links)
No description available.
7

Zur Rolle der Familie bei Essanfällen im Kindes- und Jugendalter / The role of the family in childhood and adolescent binge eating : a systematic review

Tetzlaff, Anne, Hilbert, Anja 28 June 2016 (has links) (PDF)
Fragestellung: Während der Einfluss der Familie bei Anorexia Nervosa und Bulimia Nervosa im Kindes- und Jugendalter gut belegt ist und bereits mehrmals in Übersichtsarbeiten zusammengefasst wurde, liegen derzeit wenige Befunde zum Zusammenhang zu Essanfällen ohne kompensatorische Verhaltensweisen vor. Ziel dieser systematischen Übersichtsarbeit ist es daher, familiäre Einflussfaktoren auf die Entstehung und Aufrechterhaltung von Essanfällen zu beschreiben. Methodik: Eine systematische Datenbanksuche für Studien zum Zusammenhang von familiären Faktoren und Essanfällen wurde durchgeführt. Ergebnisse: Die eingeschlossenen Studien zeigten einheitlich, dass eine unsichere Bindung des Kindes, eine geringere Familienfunktionalität und geringere emotionale Unterstützung mit Essanfällen assoziiert sind, elterliche Arbeitslosigkeit sowie elterliche Depressionen retrospektive Korrelate darstellen und weniger Familienmahlzeiten und häufige kritische Kommentare über Figur und Gewicht innerhalb der Familie variable Risikofaktoren für Essanfälle sind. Inkonsistente Befunde fanden sich hingegen bezüglich der Familienstrukturen, dem Vorliegen elterlicher Essstörungen und Diäthalten sowie dem Erkennen von Essanfällen beim eigenen Kind. Geschlechterunterschiede im Zusammenhang zu familiären Beziehungen und gewichtsbezogener Stigmatisierung wurden identifiziert. Schlussfolgerungen: Ebenso wie bei anderen Essstörungen scheinen familiäre Einflussfaktoren auch bei Essanfällen eine wichtige Rolle einzunehmen. Daher könnten eine Diagnostik familiärer Einflüsse und familientherapeutische Interventionen in der Behandlung von Essanfällen im Kindes- und Jugendalter hilfreich sein. Mithilfe von prospektiven Studiendesigns könnten die divergierenden Ergebnisse aufgeklärt werden. / Objective: While family factors in childhood and adolescent anorexia nervosa and bulimia nervosa are well-documented and were often reviewed before, less is known about these influences on binge eating without compensatory behavior. Therefore, the aim of this systematic review is to describe family factors in the development and maintenance of binge eating. Method: A systematic literature search was conducted for studies on associations between binge eating, loss of control eating and family outcomes. Results: Consistent evidence was found for associations between binge eating and insecure attachment of the child, lower family functioning and lower parental involvement, for parental unemployment and parental depression as retrospective correlates and for variable risk factors in fewer family meals and more critical comments about weight or shape by parents. In contrast, rather inconsistent findings referred to the influence of family structures, parental eating disorders, dieting and their knowledge about child’s eating behaviour. Gender differences in associations with family relationships and weight stigmatization were identified. Conclusions: The results underline the importance of familial factors in binge eating as compared to other eating disorders. Consequently, family assessment and family-based interventions might be helpful in the treatment of childhood and adolescent binge eating. More research should clarify inconsistent findings using prospective designs.
8

Kvalitativ undersökning av diagnostisk och interaktiv kontroll i styrningen av högskolor : En beskrivande studie av styrdialogen / Qualitative research on diagnostic and interactive control of the management control in universities : A descriptive study of the management control

Delebeck, Maria, Ivarsson, Johan January 2021 (has links)
Problem description: The universities resources is allocated yearly through a regulation letter by the government which might make it more difficult to plan the organisation due to unforeseen events. The adaption and design of the management is a critical event that can cause negative consequences for the operation if made with deficient knowledge understanding about the cause and effect. We argue that this demands the management to clearly communicate the operations unique context, visions, goals and desired approach to create consensus within the organisation.  Research question: How does the balance between interactive and diagnostic control affect the management and the actions between top and local management in universities?  Purpose: The purpose with this research is to describe and understand how the balance between interactive and diagnostic controll in both the management and budget process affects actions in universities.  Methodology: This is a descriptive qualitative research which is mainly deductive. The empirical data is based on six different interviews from six different respondents that has been interviewed according to two different interview guides depending on which management level they were. The interview guide is based on semi structured questions that are well anchored in the theory through a operationalization scheme to fulfil the purpose of gathering the desired data to ensure a high validity.  Conclusions: Actions like budget games occurs despite reached balance between interactive and diagnostic control as a result of the universities context of being a part of the government since local savings is prohibited. / Problemdiskussion: Resursfördelningen i högskolan tilldelas varje år genom att regeringen skickar ut regleringsbrev vilket medför att förmågan att planera långsiktigt till följd av oförutsedda händelser kan försvåras. Anpassning och utformning av styrdialogen är en kritisk händelse som vid bristande förståelse kring orsak och verkan, kan resultera i negativa konsekvenser för verksamheten. Detta ställer krav på en styrdialog som förmår att tydligt förmedla verksamhetens unika kontext, vision, mål och önskat tillvägagångssätt för att skapa samsyn inom organisationen. Forskningsfråga: Hur påverkar balansen mellan interaktiv och diagnostisk kontroll styrdialog och ageranden mellan central och lokal ledning i högskolor? Syfte: Vår undersökning syftar till att beskriva och förstå hur balansen mellan interaktiv och diagnostisk kontroll i såväl styrdialog som budgetprocess påverkar ageranden i högskolor. Metod: Detta är en beskrivande kvalitativ studie med en huvudsaklig deduktiv ansats. Empirin grundar sig på intervjuer från sex olika respondenter som har intervjuats efter två olika intervjuguider beroende av ledningsnivå. Intervjuguiden är baserad på semistrukturerade frågor som är väl förankrade i teorin genom ett operationaliseringsschema i syfte att samla önskad information för att säkerställa en hög validitet. Slutsats: Ageranden såsom budgetspel uppstår trots uppnådd balans mellan interaktiv och diagnostisk kontroll till följd av högskolans kontext av att vara en statlig myndighet då lokalt sparande inte tillåts.
9

Zur Rolle der Familie bei Essanfällen im Kindes- und Jugendalter: eine systematische Übersicht

Tetzlaff, Anne, Hilbert, Anja January 2014 (has links)
Fragestellung: Während der Einfluss der Familie bei Anorexia Nervosa und Bulimia Nervosa im Kindes- und Jugendalter gut belegt ist und bereits mehrmals in Übersichtsarbeiten zusammengefasst wurde, liegen derzeit wenige Befunde zum Zusammenhang zu Essanfällen ohne kompensatorische Verhaltensweisen vor. Ziel dieser systematischen Übersichtsarbeit ist es daher, familiäre Einflussfaktoren auf die Entstehung und Aufrechterhaltung von Essanfällen zu beschreiben. Methodik: Eine systematische Datenbanksuche für Studien zum Zusammenhang von familiären Faktoren und Essanfällen wurde durchgeführt. Ergebnisse: Die eingeschlossenen Studien zeigten einheitlich, dass eine unsichere Bindung des Kindes, eine geringere Familienfunktionalität und geringere emotionale Unterstützung mit Essanfällen assoziiert sind, elterliche Arbeitslosigkeit sowie elterliche Depressionen retrospektive Korrelate darstellen und weniger Familienmahlzeiten und häufige kritische Kommentare über Figur und Gewicht innerhalb der Familie variable Risikofaktoren für Essanfälle sind. Inkonsistente Befunde fanden sich hingegen bezüglich der Familienstrukturen, dem Vorliegen elterlicher Essstörungen und Diäthalten sowie dem Erkennen von Essanfällen beim eigenen Kind. Geschlechterunterschiede im Zusammenhang zu familiären Beziehungen und gewichtsbezogener Stigmatisierung wurden identifiziert. Schlussfolgerungen: Ebenso wie bei anderen Essstörungen scheinen familiäre Einflussfaktoren auch bei Essanfällen eine wichtige Rolle einzunehmen. Daher könnten eine Diagnostik familiärer Einflüsse und familientherapeutische Interventionen in der Behandlung von Essanfällen im Kindes- und Jugendalter hilfreich sein. Mithilfe von prospektiven Studiendesigns könnten die divergierenden Ergebnisse aufgeklärt werden. / Objective: While family factors in childhood and adolescent anorexia nervosa and bulimia nervosa are well-documented and were often reviewed before, less is known about these influences on binge eating without compensatory behavior. Therefore, the aim of this systematic review is to describe family factors in the development and maintenance of binge eating. Method: A systematic literature search was conducted for studies on associations between binge eating, loss of control eating and family outcomes. Results: Consistent evidence was found for associations between binge eating and insecure attachment of the child, lower family functioning and lower parental involvement, for parental unemployment and parental depression as retrospective correlates and for variable risk factors in fewer family meals and more critical comments about weight or shape by parents. In contrast, rather inconsistent findings referred to the influence of family structures, parental eating disorders, dieting and their knowledge about child’s eating behaviour. Gender differences in associations with family relationships and weight stigmatization were identified. Conclusions: The results underline the importance of familial factors in binge eating as compared to other eating disorders. Consequently, family assessment and family-based interventions might be helpful in the treatment of childhood and adolescent binge eating. More research should clarify inconsistent findings using prospective designs.
10

Development of Cell Lysis Techniques in Lab on a chip

Shahini, Mehdi January 2013 (has links)
The recent breakthroughs in genomics and molecular diagnostics will not be reflected in health-care systems unless the biogenetic or other nucleic acid-based tests are transferred from the laboratory to clinical market. Developments in microfabrication techniques brought lab-on-a-chip (LOC) into being the best candidate for conducting sample preparation for such clinical devices, or point-of-care testing set-ups. Sample preparation procedure consists of several stages including cell transportation, separation, cell lysis and nucleic acid purification and detection. LOC, as a subset of Microelectromechanical systems (MEMS), refers to a tiny, compact, portable, automated and easy-to-use microchip capable of performing the sample-preparation stages together. Complexity in micro-fabrications and inconsistency of the stages oppose integration of them into one chip. Among the variety of mechanisms utilized in LOC for cell lysis, electrical methods have the highest potential to be integrated with other microchip-based mechanisms. There are, however, major limitations in electrical cell lysis methods: the difficulty and high-cost fabrication of microfluidic chips and the high voltage requirements for cell lysis. Addressing these limitations, the focus of this thesis is on realization of cell lysis microchips suitable for LOC applications. We have developed a new methodology of fabricating microfluidic chips with electrical functionality. Traditional lithography of microchannel with electrode, needed for making electro-microfluidic chips, is considerably complicated. We have combined several easy-to-implement techniques to realize electro-microchannel with laser-ablated polyimide. The current techniques for etching polyimide are by excimer lasers in bulky set-ups and with involvement of toxic gas. We present a method of ablating microfluidic channels in polyimide using a 30W CO2 laser. Although this technique has poorer resolution, this approach is more cost effective, safer and easier to handle. We have verified the performance of the fabricated electro-microfluidic chips on electroporation of mammalian cells. Electrical cell lysis mechanisms need an operational voltage that is relatively high compared to other cell manipulation techniques, especially for lysing bacteria. Microelectro-devices have dealt with this limitation mostly by reducing the inter-distance of electrodes. The technique has been realized in tiny flow-through microchips with built-in electrodes in a distance of a few micrometers which is in the scale of cell size. In addition to the low throughput of such devices, high probability of blocking cells in such tiny channels is a serious challenge. We have developed a cell lysis device featured with aligned carbon nanotube (CNT) to reduce the high voltage requirement and to improve the throughput. The vertically aligned CNT on an electrode inside a MEMS device provides highly strengthened electric field near the tip. The concept of strengthened electric field by means of CNT has been applied in field electron emission but not in cell lysis. The results show that the incorporation of CNT in lysing bacteria reduces the required operational voltage and improves throughput. This achievement is a significant progress toward integration of cell lysis in a low-voltage, high-throughput LOC. We further developed the proposed fabrication methodology of micro-electro-fluidic chips, described earlier, to perform electroporation of single mammalian cell. We have advanced the method of embedding CNT in microchannel so that on-chip fluorescent microscopy is also feasible. The results verify the enhancement of electroporation by incorporating CNT into electrical cell lysis. In addition, a novel methodology of making CNT-embedded microfluidic devices has been presented. The embedding methodology is an opening toward fabrication of a CNT-featured LOC for other applications.

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