Master of Science

thesisThis thesis discusses the design, modeling, and experimental validation of an inductively coupled wireless power transfer (WPT) system to power a micro aerial vehicle (MAV) without an onboard power source. MAVs are limited in utility by flight times ranging from 5 to 30 minutes. Using WPT for MAVs, in general, extends flight time and can eliminate the need for batteries. In this paper, a resonant inductive power transfer system (RIPT), consisting of a transmit (Tx) coil on a fixed surface and a receive (Rx) coil attached to the MAV, is presented, and a circuit is described. The RIPT system design is modeled to determine a suitable geometry for the coils, and the model validated experimentally. It is found that for the MAV used in this work, a suitable geometry of coils is a 19cm diameter planar spiral Tx coil made with 14 AWG copper wire, seven turns, and 5cm pitch paired with an Rx coil made of 16-20AWG wire, 13cm-20cm diameter, 1mm pitch, and one to two turns. A demonstration of an MAV being powered 11cm above the Tx coil with the WPT system in a laboratory setting is presented. The MAV consumes approximately 12 Watts. The overall power efficiency of the RIPT system from RF power source output to MAV motors is approximately 32%

Visualizing Rhetorical Awareness: Building Critical Digital Literacies Practices With Visual Rhetoric in First-Year College Composition

Visual rhetoric assignments allow students a space to practice rhetorical design with a specific audience in mind. When used in concordance with traditional writing assignments, these visual multimedia projects (such as flyers and infographics) can be a useful way for college writing teachers to build rhetorical awareness, which is one of the objectives of first-year college composition courses. This project examines the use of visual rhetoric assignments within a concurrent enrollment college writing course. Students in the course created a community-based proposal, including flyers, infographics, and a final essay. By examining these assignments for evidence of critical digital literacies (decoding, meaning making, using, analyzing, and persona), the researchers investigated how the visual projects promoted student thinking about their audience in their designs and how composition teachers could use visual assignments, in combination with traditional writing assignments in college composition courses

The effect of alfalfa (Medicago sativa) silage chop length and inclusion rate within a total mixed ration on the ability of lactating dairy cows to cope with a feed withholding and refeeding challenge

Cows fed diets containing a lower concentration of alfalfa silage (replacing corn silage) experienced greater reductions in rumen pH following a six hour feed witholding/refeeding challenge than those fed higher alfalfa concentration diets and also suffered greater short-term milk loss on the day of the challenge. Lower rumen pH in animals fed a long chop length compared to a shorter chop length raised questions over the effect of long forage particles in the diet during and following short-term feed deprivation. This research highlights the importance of maintaining feeding routines and ensuring adequate feed access throughout the day in dairy systems

Developing a sense of place in rural Alberta: experiences of newcomers

This narrative inquiry uses the talking circle, a discourse process indigenous to the North American prairies, to explore the experiences of recent international migrants to rural Alberta. The immediate intention is to address questions of rural revitalization and the creation of welcoming communities. At a deeper level, it explores the role of history, cultural negotiation, and power relations in community development. It examines place as a critical element of human experience, which has been severed under modern economic regimes. Recommendations for how we might best respond to rural migration challenges include processes for listening and responding to needs, for building trustworthy relationships, and a call to recognize Aboriginal history. Findings also point to the importance of facilitating options for migrants with temporary status in a transient global context. The study advises that learning through attentive intercultural discourse could be integral to recreating democratic communities and establishing sense of place

Post-marketing assessment of content and efficacy of preservatives in artemisinin-derived antimalarial dry suspensions for paediatric use

BACKGROUND: Artemisinin-derivative formulations are now widely used to treat falciparum malaria. However, the dry powder suspensions developed for children are few and/or are of poor quality. In addition to the active compound, the presence of a suitable preservative in these medicines is essential. In this study, an evaluation of the preservative content and efficacy in some dry suspensions available on the Kenyan market was performed. METHOD: UV spectrophotometry was used to identify the preservatives in each sample while HPLC-UV was used for quantification. After reconstitution of the powders in water, the dissolution of the preservatives was followed for 7 days. Antimicrobial efficacy of the preservatives was assessed by conducting a preservative efficacy test (PET) following the European pharmacopoeia standards. RESULTS: Four different preservatives were identified namely methylparahydroxybenzoate (MP), propylparahydroxybenzoate (PP), benzoic acid and sorbic acid. MP and PP were identified in Artesiane(® )(artemether 300 mg/100 ml), Alaxin(® )(dihydroartemisinin 160 mg/80 ml) andGvither (® )(artemether 300 mg/100 ml) respectively. Sorbic acid was presentin Artenam(® )(artemether 180 mg/60 ml) while benzoic acid was identified in Santecxin(® )(dihydroartemisinin 160 mg/80 ml) andArtexin(® )(dihydroartemisinin 160 mg/80 ml) respectively. Cotecxin(® )(dihydroartemisinin 160 mg/80 ml) did not contain any of the above preservatives. After reconstitution in water, preservativesin 50%(3/6) of the products did not completely dissolve and the PET results revealed that only Artenam(® )and Gvither(® )met the requirements for antimicrobial efficacy. The other products did not conform. CONCLUSION: These results show that paediatric antimalarial dry powder formulations on the market may contain ineffective or incorrect amounts of preservatives. This is a potential risk to the patient. Studies conducted on the dry powder suspensions should include the analysis of both the active ingredient and the preservative, including the efficacy of the latter