Broadband Dielectric Spectroscopy with a Microwave Ablation Antenna

Microwave ablation is a technique used to treat tumorous tissue. Its clinical use has been greatly expanding in the last few years. Because the design of the ablation antenna and the success of the treatment greatly depend on the accurate knowledge of the dielectric properties of the tissue being treated, it is highly valuable to have a microwave ablation antenna that is also able to perform in-situ dielectric spectroscopy. In this work, an open-ended coaxial slot ablation antenna design operating at 5.8 GHz is adopted from previous work, and its sensing abilities and limitations are investigated in respect of the dimensions of the material under test. Numerical simulations were performed to investigate the functionality of the floating sleeve of the antenna and to find the optimal de-embedding model and calibration option for obtaining accurate dielectric properties of the area of interest. Results show that, as in the case of the open-ended coaxial probe, the accuracy of the measurement greatly depends on the likeness between the calibration standards' dielectric properties and the material under test. Finally, the results of this paper clarify to which extent the antenna can be used to measure dielectric properties and paves the way to future improvements and the introduction of this functionality into microwave thermal ablation treatments

Automation of Operation and Testing for European Space Agency's OPS-SAT Mission

This thesis presents a solution for mission operation automation in European Space Agency's (ESA) OPS-SAT mission. To achieve this, the ESA internal mission automation system (MATIS) in combination with the mission control software (SCOS) are used. They control the satellite and all ground peripherals and programmes to enable fully automated and unsupervised satellite passes. The goal of this work is the transition from the existing manual operation, with a human operator watching over and controlling all systems, to an automated system. This system supports the operation engineer and replaces the operator himself. A large section of this thesis consists of the setup, configuration, integration of all programmes and virtual machines and testing of the MATIS software, as well as the Service Management Framework (SMF) which connects MATIS to non-MATIS applications like SCOS. During testing, a lot of problems could be identified, not only OPS-SAT specific ones, but also general problems applying to all missions that consider using MATIS for future operation automation. These findings and bugs discovered during testing are reported to the responsible authorities and presented in this work. Further features of this thesis are the elaborations of the mission operation automation concept and the satellite pass concept, providing an in-depth view of the automation and passes of OPS-SAT as well as the general concepts and thoughts, which can be used by other missions to accelerate integration. An additional key feature of this thesis is the newly developed standard for operation notation in Excel, which has been achieved in close cooperation with the operation engineer. Furthermore, to accelerate the process of switching from manual to automated procedures, several converters have been developed iteratively with the new standard. These converters allow fast transformation from Excel to the procedure programming language called PLUTO used by MATIS. Not only do the results and converters of this work accelerate the procedure integration by 80%, they also deliver a more stable mission automation system that can be used by other missions as well. Operation automation reduces the operational costs for satellites and space missions significantly, as well as reducing the human error to a minimum. Therefore, this thesis is the first step towards a future with complete automation in the area of satellite operations. Without this automation, future satellite cluster configurations, like Starlink from SpaceX, will not be possible to put into practice, due to their high complexity, exceeding the comprehensibility and reaction time of humans

A geometrical model for Mixed cyanide crystals

A model of diluted random field sustained by quenched volume deformations is shown to reproduce puzzling physical features found in X(CN)_{x}Y_{1-x} mixed cyanide crystals. X is an alkali metal (K, Na or Rb) and Y is a spherical halogen ion (Br, Cl or I). Critical thresholds x_c at which associated first order ferroelastic transitions disappear are calculated exactly. The diluted random field is shown to compete with compressibility in making the transition first order. Transitions are then found to remain first order down to x_c except in the case of bromine dilution where they become continuous. All the results are in excellent agreement with available experimental data.Comment: 10 pages, late

Governance-Depression in Japan. Some Reflections on the Structural Crisis of the Japanese Economy

Die japanische Ökonomie gilt als eine in Beziehungsnetze "eingebettete" Wirtschaft. Das ehemalige japanische "Erfolgsmodell" hat jedoch seit Anfang der 90er Jahre viel von seinem Glanz verloren, Anzeichen einer tiefgehenden "Governance Depression" sind unverkennbar. Typisch für das japanische Entwicklungsmodell ist eine spezifische Form der Gruppenbildung, die mit den gesellschaftlichen Legitimationsmustern von Herrschaft in enger Beziehung steht. Im vorliegenden Aufsatz wird davon ausgegangen, dass es sich hierbei um ein durchgehendes morphologisches Beziehungsmuster handelt, welches sich sowohl auf der gesellschaftlichen Mikro- als auch auf der Makroebene wiederfinden lässt. Der Aufsatz diskutiert die derzeitige Krise des japanischen Entwicklungsmodells vor dem Hintergrund seiner Erfolgsgeschichte. Die grundlegende gesellschaftstheoretische These ist: Es sind nicht die Beziehungsnetze als solche, die für die derzeitige Krise verantwortlich sind, sondern ihr Funktionswandel in einem veränderten sozialpolitischen und weltwirtschaftlichen Kontext. Nutzen und Nachteile der gesellschaftlichen Einbettung wirtschaftlichen Handelns lassen sich deswegen - nicht nur im Falle Japans - erst dann bestimmen, wenn man die wirtschaftliche Strukturentwicklung in einer dynamischen Perspektive untersucht.The Japanese economy is often regarded as an "embedded economy" structured by social networks. However, the one-time Japanese "model of success" has lost much of its appeal since the beginning of the 90ies. Signs of a deep rooted "goverance-depression" cannot be overlooked. The Japanese model of development is characterized by a special mode of group-building that is related to the patterns of legitimation of social governance. This article is based on the assumption that these group-structures form an ongoing morphological pattern that can be identified at each level of the societal structure. The article views the present structural crises as the reverse side of the earlier success story of the Japanese economy. The argument is: Not the social networks as such but their concrete mode of functioning in changing political and economic contexts are the structural causes of crisis. For that reason the usefulness and the disadvantages of "embedding" economic action can only be taken into full consideration if the structural development of any given economy - including the Japanese one - is studied from a point of view that takes full account of the dynamics of economic action

Ein neuer Geist des Kapitalismus? Paradoxien, Ambivalenzen, nicht intendierte Folgen

"Die steigende Bedeutung von Beziehungsnetzen in der organisatorischen Umwelt, von personalisierten Teamstrukturen in der organisatorischen Binnenwelt sowie die Verknüpfung beider Strukturelemente in interorganisatorischen Kontexten verweist auf eine Paradoxie der Netzwerkökonomie, die sich im Anschluss an Mayntz folgendermaßen beschreiben lässt: Weil die relevante Umwelt von Organisationen zunehmendvon anderen Organisationen gebildet wird, bedürfen sie zur Erzeugung von Vertrauen und Kooperation verstärkt solcher Beobachtungen, die von Personen ausgehen und auf der Ebene der Interaktionsbeziehungen platziert sind. Daraus resultiert ein weiteres Paradox: Auf Seiten der Individuen invisibilisiert diese Beobachtungsform zunehmend Organisation. An die Stelle eines klar geschnittenen Mustersvon Rechten und Pflichten im organisatorischen Rahmen treten weitgehend unbestimmte, stark individualisierte und marktorientierte Formen von Arbeit und Anerkennung. Dieses Paradox lässt sich in Anschluss an Türk vielleicht so erklären: In der tayloristischen Phase stand die Dimension von Organisation als Gebilde im Vordergrund. Der 'affluent worker' definierte sich über den Lohn, d.h. den Organisationsertrag und nicht über den Sinn seiner Arbeit. Der Prozess der Normalisierung und Disziplinierung der Arbeit wurde hingegen invisibilisiert und auf technische Sachzwänge zurückgeführt. In der heutigen Phase des Netzwerkkapitalismus stehen hingegen die dysfunktionalen Folgen der Taylorisierung im Zentrum der Aufmerksamkeit. Um diese Dysfunktionen in den Griff zu bekommen, setzen Unternehmen verstärkt auf Kooperation und informelle Beziehungen. Auf diese Weise wird Organisation als Gebilde zunehmend invisibilisiert. Es entstehen neue Formen 'konnexionistischer' Ausbeutung, die die Zurechenbarkeit von Leistungen und die Zugehörigkeit der Akteure verschleiern. Diese Nutzung personaler Kompetenzen, Beobachtungsfähigkeiten und Motivationen ist nur möglich, weil die Individuen in der 'Organisationsgesellschaft' auch in den außerorganisatorischen Lebenswelten in großem Ausmaß zu 'organization men' bzw. organization women geworden sind. Identitäten, kulturelle Überlieferungen und Vergemeinschaftungen sind mittlerweile in vielen Hinsichten vom Kunden- und Selbstvermarktungsdenken durchtränkt. Selbst widerständigen Formen sozialer Selbstbehauptunglassen sich immer mehr als 'sekundäre Anpassung' (Goffman) an die Prozesse des Organisierens begreifen." (Autorenreferat

Cement Embolization into the Vena Cava and Pulmonal Arteries After Vertebroplasty: Interdisciplinary Management

AbstractPurposeTo report interdisciplinary management in a case of cement embolization into the inferior vena cava and peripheral pulmonary arteries after percutaneous vertebroplasty.Case reportA 50-year-old female patient with an osteoporotic compression fracture of the second lumbar vertebra underwent percutaneous vertebroplasty with polymethylmetaacrylate. Thereafter, CT scanning revealed small asymptomatic cement emboli in peripheral pulmonary arteries, along with a hook-shaped cement fragment in the inferior vena cava. Due to the risk that the large cement fragment could migrate to the pulmonary arteries and cause serious complications, they were retrieved from the inferior vena cava by an endovascular technique and extracted through a surgical groin incision. The patient received anticoagulant treatment for 3 months and is free of complaints after 1 year.ConclusionThis case shows that this rare complication following vertebroplasty can be successfully managed with an interdisciplinary approach

The Buen Vivir as a counter-hegemonic movement under Robert Cox’s hegemonic theory

Development has long been considered as a lineal path to be followed in order to attain progress; the foundations from which it emanates are well embedded in western standards. For the last decade the conception of development has entered a phase of deconstruction after several criticisms, thus allowing new emergent discourses to gain space in different ways to attain welfare and growth. The “buen vivir” appears as an alternative in Ecuador, which it denies development as an irrevocable action that states pursue and portrays the importance of social and ecological imperatives, but the question is can it really replace mainstream development theories. This work will contextualize the "buen vivir" as a counter-hegemonic movement under Robert Cox's hegemonic theory and use the Ecuadorian case to analyze its possibilities to work locally and further on have a place in the international arena.En las últimas décadas la concepción de desarrollo ha entrado una fase de de-construcción tras recibir un sin número de críticas, así permitiendo nuevos discursos ganar espacio y proponer alternativas. El "Buen Vivir" aparece como una alternativa en Ecuador, negando al desarrollo como visión inequívoca para los países a seguir y propone la importancia de imperativos sociales y ecológicos. La pregunta permanece en sí este nuevo discurso puede ser viable como alternativa al desarrollo. Este trabajo contextualiza al "Buen Vivir" como un movimiento contra-hegemónico bajo la teoría de Robert Cox y utiliza el caso Ecuatoriano como plataforma de análisis para el ámbito local y a priori como posibilidad de alternativa al desarrollo en el plano internacional

The Current State of High School Female and Minority Self-efficacy and Interest in STEM in Chatham County, Georgia

With the growing demand for science, technology, engineering, and mathematics (STEM) jobs in the U.S., the attainment of college degrees in these areas is of paramount importance. Both federal and state governments have established initiatives to grow the number of STEM degrees earned by women and racial minorities, as these groups graduate in STEM disciplines and work in STEM fields at a lower rate than that of their majority counterparts. The factors that can deter women and underrepresented minorities from pursuing STEM careers have been identified with one of the most prominent being low self-efficacy, or a reduced belief in one’s capability of accomplishing a goal or task. This study aimed to assess the current level of self-efficacy of Chatham County, Georgia high school students in the STEM disciplines and their interest in pursuing a STEM career. No difference in the levels of self-efficacy in mathematics and science was reported by females and males; however, males reported significantly higher self-efficacy in engineering and technology compared to females. When asked about the future, females and males reported no difference in interest in a variety of STEM vocations; however, males had a significantly stronger preference for jobs in the areas of physics, computer science, medicine, energy, and engineering compared to females. Race did not influence self-efficacy in the three STEM areas, but interest in careers in the physical sciences was low among underrepresented minority students. Continued implementation of strategies to create and maintain female self-efficacy and interest in STEM, especially in engineering and technology, remains a necessity. While underrepresented minority students appeared to possess self-efficacy in the STEM disciplines during high school, strategies are needed to ensure their successful progression through STEM degree programs and later obtainment of a STEM job

Broadband Dielectric Spectroscopy with a Microwave Ablation Antenna

Microwave ablation is a technique used to treat tumorous tissue. Its clinical use has been greatly expanding in the last few years. Because the design of the ablation antenna and the success of the treatment greatly depend on the accurate knowledge of the dielectric properties of the tissue being treated, it is highly valuable to have a microwave ablation antenna that is also able to perform in-situ dielectric spectroscopy. In this work, an open-ended coaxial slot ablation antenna design operating at 5.8 GHz is adopted from previous work, and its sensing abilities and limitations are investigated in respect of the dimensions of the material under test. Numerical simulations were performed to investigate the functionality of the floating sleeve of the antenna and to find the optimal de-embedding model and calibration option for obtaining accurate dielectric properties of the area of interest. Results show that, as in the case of the open-ended coaxial probe, the accuracy of the measurement greatly depends on the likeness between the calibration standards’ dielectric properties and the material under test. Finally, the results of this paper clarify to which extent the antenna can be used to measure dielectric properties and paves the way to future improvements and the introduction of this functionality into microwave thermal ablation treatments

A Model to Describe Transport Properties in Bi2Sr2(CazPr1−z)Cu2O8+yBi_2Sr_2(Ca_zPr_{1-z})Cu_2O_{8+y}

A pseudo-spin model is proposed, as a means to describe some transport properties (resistivity and Hall mobility) in $Bi_2Sr_2(Ca_zPr_{1-z})Cu_2O_{8+y}$. Our model is based in a double-well potential where tunneling in a given site and interaction between different lattice sites are allowed only through the excited states. Doping of the pure system by the addition of $Pr$ increases the ratio between the activation energy and the tunneling constant. The model Hamiltonian displays some features which are present in the hydrogen-bonded ferroelectrics. Its dynamics is treated in the random phase approximation and the characteristic frequency (time) is used in a Drude formula in order to obtain some transport properties of the system, namely the electric resistivity and the Hall mobility. The quantities calculated in this work are compared with the experimental data of B. Beschoten, S. Sadewasser, G. G\"{u}ntherodt and C. Quitmann [Phys. Rev. Lett.77, 1837(1996)].Comment: 14 pages, 4 figure