Characterization of dielectric charging in RF MEMS capacitive switches

RF MEMS capacitive switches show great promise for use in wireless communication devices such as mobile phones, but the successful application of these switches is hindered by reliability concerns: charge injection in the dielectric layer (SiN) can cause irreversible stiction of the moving part of the switch. We present a new way to characterize charge injection. By stressing the dielectric with electric fields on the order of 1 MV/cm, we inject charge in the dielectric, and use a new method to measure the effects it has on the C-V curve. Instead of measuring the change in the pull-in voltage, this method measures the change in the voltage at which the capacitance is minimal. This way, no extra charge is injected during the measurement of the amount of injected charge, which reduces the effect it has on the tested switches, so that the effect of the intentionally induced stress voltage is not obscured by the measurement method

Treatment modalities for chronic limb-threatening ischemia: strategies and outcomes

Chronic limb-threatening ischemia (CLTI) is a serious condition in which there is inadequate blood flow to the foot due to calcification of the vessels causing rest pain or unhealing wounds. Treatment by endovascular revascularization is preferred because of the minimally invasive technique. However, endovascular revascularization for the treatment of CLTI can be difficult due to the severity of the calcification and extensiveness of the disease in the below-the-knee arteries. This thesis exists of 3 parts: (1) outpatient care of CLTI patients, (2) balloon angioplasty techniques for the treatment of below-the-knee lesions and (3) the evaluation of the percutaneous deep venous arterialization (pDVA) technique in no-option CLTI patients. For the outpatient care, a multidisciplinary approach remains essential for the treatment of a diabetic foot ulcer. The benefits of antibiotic treatment for clinically uninfected foot ulcer should be further explored. Treatment of infrapopliteal lesions with drug coated balloons has not (yet) proven its benefits over treatment with plain old balloons. For the treatment of highly calcified and long lesions, high-pressure, noncompliant balloons have shown to be safe and feasible. An ex-vivo flow model was validated to study the effects of endovascular treatments on the arterial wall in a standardized, physiological environment, limiting the need for laboratory animal testing. Final, the pDVA technique, its outcomes and postprocedural follow-up care was evaluated in this thesis. Key elements are the acknowledgment that the DVA needs 6 weeks to develop, and the need for a multimodal approach including surveillance, wound care, and a staged amputation strategy

Levinas, Leviticus, & Language: A Case Study Exploring ACSI Maritime Teacher Challenges of Practice Due to Increasing ESL Enrollment

The purpose of this case study was to explain the perceived challenges of practice due to increasing enrollment of English Language Learners (ELLs) for ACSI teachers in the Canadian Maritimes. The theory guiding this study was ethics as first philosophy by Levinas (1981). Levinas’ theory aided in examining the ethical, relational, and linguistic challenges teachers experienced teaching ELLs. The central research question guiding this study was: what are the perceived challenges of practice K-12 ACSI Maritime school teachers face due to increasing ELL enrollment? Data was collected through pre-interview journals, semi-structured face-to-face interviews, and observations. Data analysis included transcriptions, documents, and field notes. Member checks were employed (Creswell, 2013), as was coding, which was analyzed using ATLAS.ti. Themes and outliers emerged and were examined (Yin, 2009). The research had implications for ACSI administrators and teachers who are challenged by increasing ELL enrollment

Towards a Learning-Based Theory of the Firm

This paper takes tentative steps towards a new learning-based theory of the firm. Itsobjective is to advance a separate and empirically relevant answer to the question: why do firms exist?Sometimes learning across the market will be preferred, while in other situations the firm will enjoy theadvantage. A predictive theory of the firm needs to unfold these differences between both modes oforganization. As in transaction cost economics, therefore, the strategy for deriving propositions iscomparative institutional analysis. Given a choice between the market and the firm, which is better? Thehypothesis is that learning economies will be achieved when the attributes of learning, informationexchange, and the alternative modes of organization are properly attuned to each other. On this basis,several propositions are advanced identifying factors responsible for market or firm advantage. Finally,the steps taken toward a learning-based theory of the firm are captured in three implications for economictheory and for a wider theory of performance differences between firms, which is a major concern in bothstrategic management and resource-based thinking. Some consequences of these implications arehighlighted, indicating the future research agenda