A peatland near Lake Charlotte, Nova Scotia that had been damaged by all-terrain vehicles (ATVs) was identified as a compensatory mitigation site. Restoration practices commonly used for harvested peatlands were applied to small sections of ATV damaged peatland. In the test plots, treatments of moss and shrub transplantation, fertilizer application, and straw mulch addition were applied in various combinations to determine the optimum restoration approach for specific areas within the Lake Charlotte peatland complex. The overall objective of this research was to recommend a procedure for the complete restoration of the damaged portions of the peatland. A number of different hydrological, physio-chemical and biological parameters were monitored throughout the 2009 growing season to evaluate the effectiveness of the different treatments. In conclusion, this study demonstrated that techniques developed to restore peatlands degraded by peat extraction activities are also effective for restoring peatlands impacted by ATV use.

Climate change can affect northern aquatic systems causing changes in the composition of resident species through either evolutionary or ecological processes. Rock pools near Churchill, Manitoba, Canada provide an ideal study system for studying the effect of environmental change in a metacommunity context, since salinity of the pools has increased significantly over the past quarter century, and dispersal between habitats is important in this landscape. I used a field experiment to study how zooplankton communities respond to increased salinity with two levels of dispersal limitation and three seasonal levels. I found that experimental zooplankton communities shifted from freshwater to more saline communities after a time lag of three weeks, and that highly connected pools became more similar to saline control communities faster than isolated pools. Moreover, freshwater communities manipulated later in the season changed faster to saline communities. This study highlights the metacommunity concept as a useful tool for studying environmental change. / This thesis has already been submitted to Graduate Program Services in hard copy and approved, however I was advised that I could upload it for electronic distribution as well.

Parkinson’s disease (PD) is a neurodegenerative movement disorder and a leading cause of neurological disability in the older adult population. Historically, the research and treatment of PD has focused on the associated motor symptoms. Now the non-motor symptoms such as sleep disturbance are becoming an increased focus for researchers. Deep brain stimulation (DBS) is a surgical intervention that has proven to be beneficial for PD motor symptom management. There are claims from the literature that DBS may assist with the phenomenon of sleep disturbance. A case study analysis was done to explore this concept in the DBS-PD patient population using the framework of the Symptom Management Theory. From the analysis of the subjective and objective data gathered it is clear that the phenomenon of sleep disturbance in this population is multifaceted and that DBS may play a role in managing the phenomenon of sleep disturbance for this population.

This study aimed to gain an understanding of changing active layer dynamics in the High Arctic, specifically in terms of understanding the spatial distribution of mudboils to identify climatic and landscape controls, and active layer processes driving their formation. Systematic mapping of mudboils and sediment and water sampling was undertaken at the Cape Bounty Arctic Watershed Observatory (CBAWO), Melville Island, Nunavut in 2012 and 2013. Based on borehole stratigraphic profiles taken at CBAWO, three primary soil units were determined: mudboils at surface; overburden (soil) material; and a grey, fine-grained layer at approximately 80cm depth. These soil classes were used for comparison to gain an understanding of the properties and origins of the mudboil materials. Results indicate that these features only occur late in the melt season during exceptionally warm years (2007, 2011, and 2012) and in some cases closely follow major rainfall events. High-resolution satellite imagery was analyzed to determine landscape controls over mudboil formation. Notably, mudboils were significantly associated with bare soil and polar semi-desert vegetation settings, corresponding to increased active layer depth and rate of thaw when compared to more vegetated areas. Further, localized occurrence of mudboils appears to be related to differential soil moisture retention and spatially heterogeneous soil water pressurization due to thaw into the ice-rich transient layer in warm years. We hypothesize that the locally drier locations develop soil ped structures that contribute to diapir development and mud ejection when seasonal melt and hydraulic conditions pressurize soil water. Geotechnical and geochemical analysis of soil samples indicates that mudboils at surface do not significantly differ in terms of composition and physical properties from the undisturbed overburden material. This is consistent with a fine-grained slurry likely being generated in situ from a parent bed and subsequently ejected to surface. This research provides insights into the processes and landscape controls over mudboil formation to aid in understanding localized soil water response to deep summer thaw, with implications for surface water quality and predictions and potential mitigation of permafrost-related degradation and disturbance. / Thesis (Master, Geography) -- Queen's University, 2014-05-22 13:56:49.078

Parkinson’s disease (PD) is a neurodegenerative movement disorder and a leading cause of neurological disability in the older adult population. Historically, the research and treatment of PD has focused on the associated motor symptoms. Now the non-motor symptoms such as sleep disturbance are becoming an increased focus for researchers. Deep brain stimulation (DBS) is a surgical intervention that has proven to be beneficial for PD motor symptom management. There are claims from the literature that DBS may assist with the phenomenon of sleep disturbance. A case study analysis was done to explore this concept in the DBS-PD patient population using the framework of the Symptom Management Theory. From the analysis of the subjective and objective data gathered it is clear that the phenomenon of sleep disturbance in this population is multifaceted and that DBS may play a role in managing the phenomenon of sleep disturbance for this population.

Bakgrund: Patienter på en intensivvårdsavdelning är ofta i behov av avancerad medicinsk behandling på grund av sitt livshotande sjukdomstillstånd. Återkommande störningar av sömnen är ett av de vanligaste återkommande klagomålen från patienter vilket bidrar till att perioden upplevs som särskilt svår. Syfte: Att belysa vad vuxna patienter upplever stör sömnen på en intensivvårdsavdelning. Metod: Allmän litteraturstudie där 12 vetenskapliga artiklar ligger till grund för resultatet. Resultat: I analysen av artiklarna framträdde fyra kategorier som alla tillsammans påverkade patientens sömn negativt. Kategorierna var rädsla/oro över att inte bli frisk, smärta från till exempel operationssår, inskränkning av integriteten samt störningar från vårdrelaterade interventioner såsom kontroll av vitalparametrar, munvård och förbandsbyte. Diskussion: Tidigare forskning har påvisat ljus och ljud från apparater som störande för patientens sömn, resultatet från denna studie visar dock att samtal mellan personalen är mer störande. Personalen kan behöva uppmärksamma detta och anpassa samtalsnivån därefter. Genom att informera patienten om vad som händer på intensivvårdsavdelningen kan man öka deras känsla av trygghet. Rutinmässiga vårdrelaterade interventioner skulle kunna samordnas nattetid för att ge patienterna sammanhängande sömn. Slutsats: Personal inom intensivvården skulle behöva uppmärksamma vad patienten upplever stör sömnen under vårdtiden. Ytterligare forskning med kvalitativ ansats behövs där patientens upplevelser sätts i fokus. / Background: Patients in an intensive care unit (ICU) often require sophisticated treatment due to life-threatening conditions, but disturbed sleep has been found to be one of the most reoccurring complaints from patients in intensive care. Purpose: To highlight what adults perceive disturb their sleep in an intensive care unit. Method: General literature review where twelve scientific articles form the basis of the results. Result: When analysed, four categories emerged, which when combined adversely affected patients sleep. The categories were fear/worry about not recovering, pain from e.g. surgical wounds, limitations of integrity caused by being attached to wires and tubes, and disturbance from care related interventions by staff checking vital observations, oral hygiene, wound dressings. Discussion: Previous research has found light and machinery noise disruptive, however, our findings show staff communication levels to be more disturbing. Straff need to be aware of speech noise levels, reminding colleagues when required. Informing patients of ICU activity helps increase patients’ sense of security which when combined with coordinated, care related interventions at night helps with continous periods of sleep. Conclusion: ICU staff need to identify patients concerns regarding perceived sleep disruption. Further research is required where patients perception of sleepdisturbances is in focus.

This thesis proposes and evaluates the application of a low-frequency disturbance injection, as an active islanding detection method, in a microgrid with multiple electronically-interfaced Distributed Generation (DG) units. Each DG unit is interfaced to the microgrid through a two-level Voltage-Sourced Converter (VSC). The low-frequency disturbance signal for islanding detection is injected through the q-axis control of each VSC unit. The low-frequency signal is at 1 Hz with an amplitude of up to 2.5 % of the rated VA of the VSC unit and augments the reference signal of the q-axis control. The effectiveness of the low-frequency injection for islanding detection is examined under two distinct VSC control scenarios. In the first scenario, each VSC only injects pre-determined real- and reactive-power components in the system and does not participate in frequency/voltage control. In the second scenario, the VSC controls are also equipped with frequency/real-power and voltage/reactive-power droop characteristics and thus share power and participate in frequency and voltage control of the microgrid, specifically in the islanded mode. The investigations reported in this thesis show that the proposed islanding detection method can effectively detect an islanding event under both VSC control strategies, subject to the conditions that UL and/or IEEE anti-islanding standards impose. The studies show that an islanding event can be detected within 536 ms subsequent to the instant of islanding. As part of this thesis, an eigen analysis software tool has been developed that can systematically investigate the impact of low-frequency disturbance injection on the small-signal stability and dynamic performance of the microgrid, prior and subsequent to an islanding event. This thesis concludes that the low-frequency disturbance injection-based method can be successfully applied to a multi-DG system, since (i) islanding detection is achieved within applicable standards requirements by all DG units in the system, and (ii) the low-frequency disturbance injection signal has no noticeable impact on the dynamics nor the small-signal stability of the system if its magnitude is kept below a pre specified limit.

This thesis proposes and evaluates the application of a low-frequency disturbance injection, as an active islanding detection method, in a microgrid with multiple electronically-interfaced Distributed Generation (DG) units. Each DG unit is interfaced to the microgrid through a two-level Voltage-Sourced Converter (VSC). The low-frequency disturbance signal for islanding detection is injected through the q-axis control of each VSC unit. The low-frequency signal is at 1 Hz with an amplitude of up to 2.5 % of the rated VA of the VSC unit and augments the reference signal of the q-axis control. The effectiveness of the low-frequency injection for islanding detection is examined under two distinct VSC control scenarios. In the first scenario, each VSC only injects pre-determined real- and reactive-power components in the system and does not participate in frequency/voltage control. In the second scenario, the VSC controls are also equipped with frequency/real-power and voltage/reactive-power droop characteristics and thus share power and participate in frequency and voltage control of the microgrid, specifically in the islanded mode. The investigations reported in this thesis show that the proposed islanding detection method can effectively detect an islanding event under both VSC control strategies, subject to the conditions that UL and/or IEEE anti-islanding standards impose. The studies show that an islanding event can be detected within 536 ms subsequent to the instant of islanding. As part of this thesis, an eigen analysis software tool has been developed that can systematically investigate the impact of low-frequency disturbance injection on the small-signal stability and dynamic performance of the microgrid, prior and subsequent to an islanding event. This thesis concludes that the low-frequency disturbance injection-based method can be successfully applied to a multi-DG system, since (i) islanding detection is achieved within applicable standards requirements by all DG units in the system, and (ii) the low-frequency disturbance injection signal has no noticeable impact on the dynamics nor the small-signal stability of the system if its magnitude is kept below a pre specified limit.

In this work, two different problems are addressed. In the first part, the problem of synthesizing a set of stabilizing controllers for unknown multivariable systems using direct data is analyzed. This is a model free approach to control design and uses only the frequency domain data of the system. It is a perfect complement to modern and post modern methods that begin the control design with a system model. A three step method, involving sequential design, search for stability boundaries and stability check is proposed. It is shown through examples that a complete set of stabilizing controllers of the chosen form can be obtained for the class of linear stable multivariable systems. The complexity of the proposed method is invariant with respect to the order of the system and increases with the increase in the number of input channels of the given multivariable system. The second part of the work deals with the problem of identification of model uncertainties and the effect of unwanted exogenous inputs acting on a discrete time multivariable system using its output information. A disturbance model is introduced which accounts for the system model uncertainties and the effect of unwanted exogenous inputs acting on the system. The frequency content of the exogenous signals is assumed to be known. A linear dynamical model of the disturbance is assumed with an input that has the same frequency content as that of the exogenous input signal. The extended model of the system is then subjected to Kalman filtering and the disturbance states estimates are used to obtain a least squares estimate of the disturbance model parameters. The proposed approach is applied to a linear multivariable system perturbed by an exogenous signal of known frequency content and the results obtained depict the efficacy of the proposed approach.

Thesis (M.S.)--State University of New York at Binghamton, Department of Psychology, 2007. / Includes bibliographical references.