Statics and dynamics of electrothermal micromirrors

Adaptive and smart systems are growing in popularity as we shift toward personalization as a culture. With progressive demands on energy efficiency, it is increasingly important to focus on the utilization of energy in a novel way. This thesis investigates a microelectromechanical system (MEMS) mirror with the express intent to provide flexibility in solid state lighting (SSL). By coupling the micromirror to an optical source, the reflected light may be reshaped and directed so as to optimize the overall illumination profile. In addition, the light may be redirected in order to provide improved signal strength in visible light communications (VLC) with negligible impact on energy demands. With flexibility and full analog control in mind, the design of a fully integrated tip-tilt-piston micromirror with an additional variable focus degree of freedom is outlined. Electrothermal actuators are used to both steer the light and tune the focal length. A detailed discussion of the underlying physics behind composite beams and thermal actuators is addressed. This leads directly into an overview of the two main mirror components, namely the segmented mirror and the deflection actuators. An in-depth characterization of the dynamics of the mirror is discussed including the linearity of the thermal response. Frequency domain analysis of such a system provides insight into tunable mechanical properties such as the resonant frequency and quality factor. The degenerate resonant modes can be separated significantly. It is shown that the frequency response may be tuned by straining specific actuators and that it follows a predictable pattern. As a result, the system can be scanned at increasingly large angles. In other words, coupled mechanical modes allow variable damping and amplification. A means to determine the level of coupling is examined and the mode shape variations are tracked as a function of the tuning parameters. Finally, the applications of such a device are explored and tested. Such applications include reliable signal-to-noise ratio (SNR) enhancements in VLC of 30 dB and color tunable steerable lights using laser diodes. A brief discussion of the implications of dynamic illumination and tunable systems is juxtaposed with an explanation behind the integration of an electrothermal micromirror and an all digital driver

Reducing preventable hospitalizations: A study of two models of transitional care

Purpose: Transitional care is an emerging model of health care designed to decrease preventable adverse events and associated utilization of healthcare through temporary follow-up after hospital discharge. This study describes the approach and outcomes of two transitional care programs: one is provided by masters-prepared clinical nurse specialists (CNS) with a chronic disease self-management focus, another by physicians specializing in palliative care (PPC). Existing research has shown that transitional care programs with intensive follow up reduce hospitalizations, emergency room visits, and costs. Few studies, however, have included side-by-side comparisons of the efficacy of transitional care programs varying by health care providers or program focus. Design: This is a retrospective cohort study comparing the number of Emergency Department (ED) visits and hospitalizations in the 120 days before and after the intervention for patients enrolled in each transitional care program. Each program included post-hospitalization home visits, but included difference in program focus (chronic disease vs. palliative), assessment and interventions, and population (rural vs. urban). Data from participants in the CNS program 9/2014 \u27 12/2014 were analyzed (n=98). The average age of participants was 69 and they were 65% female. Data was collected from patients from the PC program from 9/2014 to 4/2015 (n=71). Thirty participants died within 120 days after the intervention and were excluded, the remaining 41 were included in the analysis. Participants had an average age of 81 and were 63% female. Methods: For the CNS program, a secondary analysis of existing data was performed. For the PC program, a review of patient charts was done to collect encounters data. A Wilcoxon Matched-Pair Signed-Rank test was performed to test for significance. Findings: Patients in the CNS intervention had significantly fewer ED visits (p Conclusions: Both transitional programs have value in decreasing health care utilization. The CNS intervention had a more significant effect on ED visits for their target population than the PC program. Further study with randomized control trails is needed to allow for a better understanding of the healthcare workforce best fitted to enhance transitional care outcomes. Future study to examine the cost savings of each of the interventions is also needed

Metabolic and Molecular Approaches to the Study of Bacterial Communities in Wetlands of the Alberta Athabasca Oil Sands Region

Bacterial communities in wetlands from the Athabasca region (Alberta, Canada) were surveyed and their utility as bio-indicators for wetland reclamation was assessed. Sediment samples were collected from wetlands categorized as: (1) natural (off mining leases), (2) reference (on mining sites but not directly impacted by oil sands processed material (OSPM)), and (3) OSPM (directly affected by OSPM). Wetlands of the latter two groups ranged in age from 11 to 24 years. Analysis involved community level physiological profiling (CLPP) with BIOLOG™ EcoPlates, and denaturing gradient gel electrophoresis (DGGE). Multivariate analysis applied to data from both techniques revealed differences in the bacterial communities based on site type; although overlap between groups occurred. Principal component analysis (PCA) and cluster analysis applied to CLPP data revealed a trend in which communities in OSPM sites were most similar to each other, followed by those in natural sites, and communities in reference wetlands were variable. The vegetated areas of a wetland displayed increased functional richness and diversity (as measured by CLPP) compared to non-vegetated areas. DGGE analysis applied to the total bacterial community revealed the highest number of operational taxonomic units (OTUs) in OSPM samples; the 2008 and 2009 OSPM samples contained an average of 22±4.5 and 22.4±5.1 OTUs, respectively, while reference sites contained 17.7±4.9 (2008) and 16.4±1.8 (2009) and natural sites contained 17.1±4.4 (2008) and 20.5±0.7 (2009). When DGGE was applied to the bacterial subgroups, y-Proteobacteria and Actinomycetes, clustering effects based on site-type were more evident through PCA than when a total bacterial approach was taken. Within OSPM wetlands, y-Proteobacteria populations were varied while Actinomycetes were similar across sites. Overall, there are clear functional (CLPP) and genetic (DGGE) differences between bacterial communities in OSPM and less impacted sites, although communities are not distinct, potentially reflecting the age of the wetlands studied and adaptation of the communities to oil sands materials. Given that CLPP and DGGE could distinguish between communities based on site type, both may be useful for monitoring microbial communities in Athabasca wetlands throughout reclamation. In particular, CLPP and group-specific DGGE are recommended as tools for community monitoring

Biochemical, physiological and structural characterization of AzoC, a novel azoreductase from Clostridium perfringens

Azo dyes are used throughout the paper, textile, food, beverage, pharmaceutical and cosmetic industries as artificial colorants and are characterized by the presence of an azo (double nitrogen) bond. Azoreductases are bacterially-produced enzymes which are capable of breaking these azo bonds and, in some cases, can result in the production of carcinogenic metabolites. Clostridium perfringens, a common inhabitant of both the human gut and the environment, is a bacteria that produces a significant amount of azoreductase activity. The gene that encodes for this azoreductase was characterized and given the name AzoC. AzoC is very novel, as compared to similarly functioning enzymes. AzoC has been shown to preferentially reduce large molecular weight sulfonated azo dyes, such as Direct Blue 15 (992.8 g/mol), with use of NADH and FAD as cofactors. The azoreduction is much increased under anaerobic conditions as compared to aerobic conditions (4-fold greater activity under anaerobic conditions). Interestingly, with certain azo dye and cofactor conditions, the presence of the cofactors alone can cause azo dye reduction. However, with the use of an azoreductase-free control in place, this can non-enzymatic activity can be accounted for. In addition, the structure of AzoC was found to be trimeric in nature, with the AzoC monomers being held together by disulfide bonding. The secondary structure of AzoC is consistent with that of other azoreductases, despite having low sequence identity. When the azoC gene was disrupted (knocked out) by intron insertion, results suggested the presence of additional enzymes capable of azoreduction. In addition, azo dye metabolites produced following azo dye reduction were found to slow C. perfringens generation time. AzoC was found to be released following C. perfringens exposure to sulfonated azo dyes and negatively charged sulfonated compounds. This enzyme was also found to localize to the Gram-positive periplasmic region of the C. perfringens cells. The results of this study serve to fill an important gap in the literature, providing the first information on a strictly anaerobic azoreductase, as well as a link between environmental azo dye exposure and the physiological state of Clostridium perfringens cells

Libraries Sharing Technology for Sharing

Recent resource sharing technology developments in the western Canadian consortia, BC Electronic Library Network and COPPUL are discussed. Highlights include the shelf status project of BC ELN, combining the functionality of a union catalogue with live lookup of circulation status via Z39.50, a tagging feature for the locally developed A to Z list CJDB (CUFTS Journal Database), a locally developed federated search tool, dbwiz, the Open Journal Systems software of the Public Knowledge Project, and the COPPUL Animated Tutorials Sharing Project

Pre- and Post-Occupancy Evaluation of Resident Motivations for and Experiences of Establishing a Home in a Low-Carbon Development

There is some understanding of how an individual’s daily practices consume resources in the home, but the home as a space itself and peoples’ relationships to it remain an interesting research area. In this paper, residents of an Australian low-carbon development (LCD) are studied in order to discover the expectations and motivations driving them to move to their new home, the emotional landscape of the home, and their subsequent experiences living in an LCD. This exploration through mixed methods and a post-occupancy evaluation enables a longitudinal empirical study of the motivations, perceptions, expectations and experiences of an LCD residence. This study aims to further conceptualize the social understanding of a home and what people consider when moving into an LCD, along with the post-occupancy experiences that are important for establishing LCDs in the future. The results show that a home is associated with being a place of community, sustainability, safety and comfort, as well as a place that incorporates aesthetically pleasing features. The motivation for residents moving into an LCD is to have housing stability, live the life they want (including performing sustainable practices) and enjoy the attractive design of the LCD. The user experiences of living in an LCD include unexpected design influences on daily practices and an appreciation of the community atmosphere created. The strong sense of community and the self-reported thermally comfortable homes met residents’ expectations post-occupancy. This research is of interest to academics in the low-carbon and social science sectors, real-estate agents and property developers, as it provides insight into motivations and expectations of low-carbon dwelling residents

Effects of solute concentrations on kinetic pathways in Ni-Al-Cr alloys

The kinetic pathways resulting from the formation of coherent L12-ordered y'-precipitates in the g-matrix (f.c.c.) of Ni-7.5 Al-8.5 Cr at.% and Ni-5.2 Al-14.2 Cr at.% alloys, aged at 873 K, are investigated by atom-probe tomography (APT) over a range of aging times from 1/6 to 1024 hours; these alloys have approximately the same volume fraction of the y'-precipitate phase. Quantification of the phase decomposition within the framework of classical nucleation theory reveals that the y-matrix solid-solution solute supersaturations of both alloys provide the chemical driving force, which acts as the primary determinant of the nucleation behavior. In the coarsening regime, the temporal evolution of the y'-precipitate average radii and the y-matrix supersaturations follow the predictions of classical coarsening models, while the temporal evolution of the y'-precipitate number densities of both alloys do not. APT results are compared to equilibrium calculations of the pertinent solvus lines determined by employing both Thermo-Calc and Grand-Canonical Monte Carlo simulation.Comment: Submitted to Acta Materialia, June, 200

Let\u27s Cure Cancer!

From ancient Egypt to modern times, scientists have been learning new ways to prevent, diagnose, and treat cancer. In this book, you’ll learn about cancer and how veterinarians, veterinary technicians, physicians, and other scientists are working together to find a cure for cancer in people and their pets.https://docs.lib.purdue.edu/vetbooks/1003/thumbnail.jp

Chewing Speed Does Not Follow Typical Patterns of Motor Slowing with Age

Aging adults experience gradual structural changes in nerve and muscle tissues that impair their ability to exploit speed as an effective movement strategy. The aim of the study was to examine whether chewing rates demonstrate a level of age-related neuromotor decline similar to other motor tasks. Fifteen young (20-40 years) and fifteen healthy older adults (60+ years) completed a battery of motor tasks including: walking, finger tapping, simple reaction time, postural sway, and chewing. Gait metrics were collected using a 20-foot pressure-sensitive walkway. All walking was performed at a preferred speed. Participants tapped an accelerometer affixed to a table at a preferred rate. Upper extremity reaction time was recorded by depressing a mouse button with an associated timing mechanism, whereas a similar foot pedal interface was used to measure lower extremity reaction time. Postural sway data was collected using a force plate. Surface electromyography of the masseter was used to record fast(2Hz), slow(1Hz), and preferred chewing rates. Fast and slow chewing rates were set using an auditory metronome which was switched off during recording. Age comparisons for each task were performed using general linear modeling, with additional considerations for chewing speed effects and interactions for the chewing task. The results reveal that older adults demonstrate a general slowing of movement with the exception of chewing speed which appears to be preserved with aging. Regardless of age, preferred chewing rates were nearly identical. Preservation of chewing rates compared to other motor tasks may be due to the difference in anatomical innervation between muscles of mastication and the limbs. Masticatory muscles receive bilateral innervation including ipsilateral and contralateral inputs from the motor cortices, whereas limb muscles receive mainly unilateral innervation from the contralateral cortex. The neural redundancy may preserve chewing rates despite age-related degradation of the system.https://digitalcommons.odu.edu/health_sciences/1009/thumbnail.jp