Surface micro-discharge (SMD)

There is an urgent need for an efficient technology of disinfection and sterilization in view of the alarming dimensions health care-associated infections (HAIs) have reached. Cold atmospheric pressure plasma (CAP) can be utilized for hygienic and medical purposes, in particular in surface decontamination applications, and provides a promising alternative to the conventionally used sterilization techniques. Surface Micro-Discharge (SMD) offers a technology for generating CAP that can be applied to wide areas. In the present work, I investigate the plasma chemistry involved in the inactivation of microorganisms by application of the SMD in order to optimize the antimicrobial effect. For this purpose, different strains of vegetative bacteria and bacterial endospores are exposed to the SMD with experimental parameters such as the gas composition, power input, treatment duration and humidity varied. At the same time, the concentration of ozone produced by the SMD is monitored, and its correlation with the antimicrobial efficacy is investigated. I demonstrate that the bactericidal effect of the SMD on both the Gram-negative Escherichia coli and Gram-positive Enterococcus mundtii is similar and strongly correlates with the ozone concentration. The sporicidal effect on Geobacillus stearothermophilus is crucially affected by the humidity, whereas the ozone concentration appears to have no influence. In addition, I investigate the dynamic behavior of ozone produced by the SMD by varying the geometry and the time interval for the plasma generation and by igniting the plasma in two subsequent phases with different frequencies. Possible explanations for the obtained results are provided. This work fortifies the role of SMD as an efficient sterilization method and discloses diverse possibilities for optimizing the antimicrobial effect.Die Häufigkeit der Krankenhausinfektionen und ihre Auswirkung haben alarmierende Ausmaße angenommen. Angesichts dessen besteht ein akuter Bedarf an einer effizienten Technologie für Desinfektion und Sterilisation. Die Anwendung von kaltem atmosphärischen Plasma (englisch: cold atmospheric plasma, CAP) für die Hygiene und Medizin, insbesondere für die Oberflächendekon-tamination, stellt einen Versuch dar, eine schnelle und effektive Sterilisationstechnik zu schaffen. Die Oberflächenentladung (englisch: Surface Micro-Discharge, SMD) bietet eine Technologie für die Erzeugung und Anwendung von CAP. In der vorliegenden Arbeit analysiere ich die antimikrobiellen Eigenschaften der SMD, um die Inaktivierungsmechnismen besser zu verstehen und den antimikrobiellen Effekt zu optimieren. Hierzu werden unterschiedliche Stämme von vegetativen Bakterien und bakteriellen Endosporen unter unterschiedlichen Bedingungen, inklusive der Gaszusammensetzung, der Eingangsleistung, der Behandlungsdauer und der Luftfeuchtigkeit, dem SMD-Plasma ausgesetzt. Gleichzeitig wird die Konzentration des im SMD-Plasma erzeugten Ozons gemessen, um den Zusammenhang mit dem antimikrobiellen Effekt zu untersuchen. Ich zeige in der vorliegenden Arbeit, dass eine SMD-Behandlung auf die gramnegative Escherichia coli und den grampositiven Enterococcus mundtii eine ähnliche Wirkung erzielt. Zudem hängt die bakterizide Wirkung der SMD stark von der Ozonkonzentration ab. Die Luftfeuchtigkeit spielt eine erhebliche Rolle bei der sporiziden Wirkung der SMD auf Geobacillus stearothermophilus, wobei hier die Ozonkonzentration keine Rolle zu spielen scheint. Darüber hinaus untersuche ich die Dynamik der Konzentration des im SMD-Plasma erzeugten Ozons, indem die Geometrie und das Zeitintervall für die Erzeugung der Entladung variiert werden, und indem die Entladung in zwei aufeinander folgenden Phasen mit verschiedenen Frequenzen gezündet wird. Mögliche Erklärungen für die beobachteten Ergebnisse werden vorgeschlagen. Die vorliegende Arbeit untermauert die Rolle der SMD als eine effiziente Sterilisationstechnik und offenbart unterschiedliche Möglichkeiten für die Optimierung des antimikrobiellen Effekts der SMD. Jedoch konnte im Rahmen dieser Arbeit nicht für alle Beobachtungen eine zufriedenstellende Erklärung geliefert werden. Weiterführende Forschungsarbeiten werden daher nahegelegt

Television, race and national identity : a study of South Africa's lifestyle programme Top billing

Includes bibliographical references (leaves 81-93).This thesis is an in-depth investigation into the weekly lifestyle/magazine programme Top Billing, aired on SABC3 (South African Broadcasting Corporation) – primarily in South Africa and in other surrounding African nations – to a total of over 6 million viewers. In its eighteenth year on South African television, Top Billing has entered the domestic lives of its viewers weekly, and has markedly become one of the country’s longest-running lifestyle and entertainment programmes. This study investigates the various meanings and pleasures that loyal viewers of Top Billing make of the programme, and how these "meanings" relate to their identities as middle class South Africans. Categorised as the "lifestyle" programme, it arguably has significant effects on the lifestyle and lives of its viewers. Studies on the "lifestyle" programme genre, especially in context to contemporary television studies, has not been widely written about. Further, as there is growing interest and a need for ethnographic and audience studies on the impact of television, particularly in Africa, this study thoroughly examines Top Billing in situ - in a media-saturated, post-modern, post-apartheid society in South Africa, while simultaneously locating the study in a larger, cross-disciplinary landscape. Since "meanings" are a cultural and social formation, the study examines the concept of "ideology" as a site of struggle; a place for the negotiation of race, gender, and other identities. The study brings to the fore the hegemonic ideology projected and "re-presented" by Top Billing, by taking an in-depth look at the makeup of the programme – both externally and internally, its relationship with its broadcaster and other social markers of society, and its audience. Through the use of content analysis, in-depth interviews and ethnography, this thesis examines issues of imbalanced representation of race and class, and the effects of commercialisation which take toll on the media landscape today. By further investigating the signifying role of the media and the ways in which Top Billing is constructed, the study determines ways in which identity is informed by Top Billing

Motion compensated images using Rgb data

A motion compensation algorithm correcting not only for translation but also for rotation, scaling, and shearing, is investigated in this thesis. Our work also includes noise detection and noise compensation due to the variation of the light. The probability distribution of the noise is investigated. The variation of the light could occur due to the voltage variation or due to the sunlight variation in the presence of clouds, or other reasons. Practical results have also been obtained by applying our theory to moving pictures

P-13 “But a Woman Who Fears the Lord is to Be Praised”: A Practical Vision in Proverbs 31

Proverbs begins with an exposition on what the “fear of the Lord” entails and ends with the description of the woman of noble character who fears the Lord (Proverbs 31:30). As few scholars have considered the woman of Proverbs 31 in connection to the “fear of the Lord,” this project overviews aspects of the “fear of the Lord” in the Old Testament, including all specific verses containing the phrase, and examines the significance of their connections with Proverbs 31. The contributions of this study include theological and practical implications of what it means to live a life fearing the Lord

The Chronology of the Events in Zechariah 12-14

In current scholarship, there is a lack of consensus on the timing of the specific events in Zechariah 12-14, with a focus on eschatological or sequential chronologies. Preliminary exegetical research has revealed many connections between the three chapters. For instance, the phrase “in that day” ( ביום־ההוא ) occurs 17 times (versus four times in the rest of Zechariah). This concentrated usage closely interconnects the three chapters and suggests that the timeliness of all of the events is in close succession. Through findings in literary structures, key words, and intertextualities with other passages of the Old Testament, the conclusion is that the events in Zechariah 12 and 13 occur in one day. Even more, there exist literary structures and patterns that seem to support the idea that the various “in that day” events in Zechariah 14 occur in a single time, which is later than the day in Zechariah 12-13

Voltage Driven Translocation of Polyelectrolytes through Nanopores

Recently, translocations of polyelectrolyte molecules through membrane channel protein pores or solid-state nanopores have been actively studied. Although the polymer translocation researches emerged mainly due to technological demands in terms of genome sequencing, the detailed physics of the single molecule transport through a narrow channel remains fully understood. To obtain further understanding of common features of the translocation process, this thesis focuses on the effects of salt concentration, pore-polymer electrostatic interactions, and externally applied electric field on the voltage-driven polymer translocations. The study is carried out by performing a series of systematically designed experiments using alpha-hemolysin (αHL) protein pore to investigate the salt concentration effects on the frequency of polymer capture by the pore and those on the subsequent polymer translocation process under various externally applied electric fields and pH. First, we demonstrate that the polymer-pore electrostatic interactions are important in dictating the rate of polymer capture by the αHL pore, controlled by the salt concentration in the donor (cis) compartment through charge screening effects. Upon the presence of a salt concentration asymmetry between the donor and the recipient (trans) compartments, the polymer capture rate is observed to be governed by coupling between the polymer-pore electrostatic interactions and additional enhancement in the electric field arising from the salt concentration asymmetry. Next, we study salt concentration effects on dynamics of polymer threading process, by measuring durations of successful translocations in various salt concentrations in cis and trans under different pH. We find that salt concentrations in cis and trans influence the polymer threading process differently, depending on pH. A theoretical model is employed to demonstrate that the charge density of the polymer chain inside the pore is a critical factor in controlling the translocation process upon varying the salt concentrations. Lastly, a new methodology to evaluate molecular weight distributions of polyelectrolyte solutions is proposed using the polymer translocation technique is proposed. The experimental results demonstrate that the translocation technique can be a competitive method for estimating the broad molecular weight distributions of polyelectrolytes in comparison with conventional mass spectroscopy techniques