title: Buckling Restrained Braces for the Seismic Strengthening of a Five-Storey Reinforced Concrete Frame Structure

title: Diagonales ductiles confinées pour le renforcement parasismique d’un bâtiment de cinq étages à ossature en béton armé

subject:
Buckling Restrained Brace
Seismic
Fast Non-Linear Analysis
reinforced concrete structure
Seismic dampening system
Uniform Hazard Spectrum

abstract: In 2008, construction commenced on a project to renovate a five storey reinforced concrete structure on the grounds of the Royal Military College of Canada. One of the elements of this renovation was a seismic retrofit, which included the use of 28 unique Buckling Restrained Braces (BRBs) that were designed and installed as a seismic strengthening and dampening system. This research involved the testing of three full-scale 9 m long BRB specimens in an individual uniaxial subassemblage. During the qualification testing, it was apparent that the as-built BRBs were constructed of material which greatly exceeded the specified 248 MPa yield-strength, resulting in braces that exceeded the intended design capacity. Following the qualification testing, one module of the concrete-frame building was modelled using a commercial finite element analysis program and was subjected to both static and dynamic forces. The dynamic analysis applied a Fast Non-Linear Analysis (FNA) using a series of five synthetic time-history functions that are compliant with the 2010 National Building Code of Canada (NBCC). It was concluded that both the designed and as-built braces remain elastic and will only perform plastically in the event of a seismic ground motion between two and five times larger than the Uniform Hazard Spectrum of the NBCC with a probability of exceedance of 2% in 50 years. Although this Seismic Force Resisting System (SFRS) remains chiefly elastic, this seismic upgrade has nevertheless achieved a rigid and effective SFRS. While this over strengthened seismic upgrade will not perform as originally intended, the now robust bracing system will provide effective lateral support and adequate stiffness to the reinforced concrete frame. The as-built BRBs will also greatly reduce the inter-storey drifts during a seismic event.

abstract: Des travaux de construction ont été entrepris en 2008 dans le cadre d’un projet visant à moderniser un bâtiment de cinq étages en béton armé sur les terrains du Collège militaire royal du Canada. L’un des éléments de cette modernisation était une amélioration parasismique qui incluait l’emploi de 28 éléments de diagonales ductiles confinées (DDC). Ces éléments ont été conçus et installés pour servir de système de renforcement et d’amortissement parasismique. La recherche faisant l’objet du présent rapport incluait l’essai de trois spécimens en vraie grandeur de DDC de 9 m de longueur dans un sous-ensemble uniaxial individuel. Au cours des essais de qualification, il s’est avéré que les DDC étaient fabriquées d’un matériau qui dépassait de loin la limite d’élasticité de 248 MPa prescrite, ce qui leur conférait une résistance supérieure à la valeur prévue. Suite aux essais de qualification, un module du bâtiment à ossature de béton a été modélisé à l’aide d’un programme commercial d’analyse aux éléments finis et a été soumis à des forces statiques et dynamiques. L’analyse dynamique appliquée utilise une approche non-linéaire rapide (ANLR) à l’aide d’une série de cinq fonctions synthétiques de variation en fonction du temps qui sont conformes au Code national du bâtiment – Canada 2010 (CNB). Il fût conclu que les contreventements conçus et ceux construits demeureront élastiques et ne se comporteront de façon plastique qu’en présence d’un mouvement sismique du sol se situant entre deux et cinq fois la valeur de calcul ayant une probabilité de dépassement de 2 % en 50 ans selon le spectre de risque uniforme (SRU). Bien que ce système de résistance aux forces sismiques (SRFS) demeure principalement élastique, cette amélioration parasismique a permis de réaliser un SFRS rigide et efficace. Bien que cette ossature parasismique sur-résistante ne se comporte pas selon l’objectif initial, le système de contreventement robuste offrira un soutien latéral efficace et une rigidité adéquate à l’ossature de béton armé. Les DDC tels que construits réduiront aussi grandement les glissements entre étages lors d’un événement sismique.


title: EQUIVALENT FRESHWATER MODELS FOR COASTAL AQUIFERS

title: MODÈLES D'EAU DOUCE ÉQUIVALENTS DE AQUIFÈRES CÔTIERS

contributor: Royal Military College of Canada / Collège militaire royal du Canada

subject: Coastal aquifer

subject: Saltwater Hydraulic Conductivity

subject: SEAWAT

abstract:
The aim of this study was to investigate the impact of saltwater intrusion on the transient hydraulic behavior of coastal aquifers and to develop an Equivalent Freshwater Modeling (EFM) approach.  The EFM approach proposed here focuses on the use of an Equivalent Freshwater Hydraulic Conductivity.
A two dimensional finite difference saltwater/freshwater model was developed using SEAWAT. An equivalent two dimensional freshwater-only model was also developed using MODFLOW. Both saltwater/freshwater and freshwater-only models were run under different recharge and pumping conditions. A comparison between the two models’ behaviour was held to identify possible relationships between the hydraulic conductivity (Ks) of the saltwater/freshwater model and the hydraulic conductivity (Kf) of the freshwater-only model.  For each value of Ks a calibration exercise was performed to choose the equivalent Kf value that gives the minimum Root Mean Square Error between the two models. Plots of the relationship between Ks  and the optimal Kf values were generated for a range of Ks values and for a range of pumping conditions represented by the ratio of pumping rate over the freshwater lens thickness, (Q/Bf). The optimal Kf values were then tested with three dimensional models.
From the different simulation scenarios we found that the presence of saltwater intrusion does not significantly affect the behavior of fine sand aquifers (Ks < 5 m/d), under the full range of pumping and freshwater lens thicknesses considered in this study. In medium sand aquifers (10 < Ks < 25 m/day), the presence of the intrusion requires an Equivalent Freshwater Hydraulic Conductivity (Kf) that is 20 to 30% higher than the original value, but the required Kf is fairly independent of the pumping over the freshwater lens thickness ratio (Q/Bf) In coarse sand aquifers (Ks > 45 m/day), the saltwater presence does have a significant effect on the aquifer behavior and the ratio of Kf over Ks is significantly affected by the freshwater lens thickness and the pumping rate.
The 3-D model verifications, that were performed with Fine Sand and Medium Sand Hydraulic Conductivities only, confirmed the Kf /Ks relationships that were developed with the 2-D models.  The performance of the EFM approach was found to depend on the aquifer hydraulic conductivity, the freshwater lens thickness and the intensity of the pumping applied to the models.

abstract:
Le but de cette étude était d’investiguer l’impact des intrusions salines sur le comportement hydraulique transitoire des aquifères côtiers et de développer une approche de Modélisation Équivalente d’Eaux Douces (MEED).  L’approche MEED proposée ici, est axée sur l’utilisation d’une Conductivité Hydraulique d’Eau Douce Équivalente.
Un modèle bidimensionnel eaux salines / eaux fraiches en différence finies a été développé à l’aide de SEAWAT.  Un modèle bidimensionnel eaux fraiches équivalent a aussi été développé avec MODFLOW. Les deux modèles ont été exécutés sous différentes conditions de recharge et de pompage.  Une comparaison entre les deux modèles a été effectuée pour identifier les relations possibles entre la conductivité hydraulique (Ks) du modèle eaux salines / eaux douces et la conductivité hydraulique (Kf) du modèle eaux douces.  Pour chaque valeur de Ks un exercice de calibration a été réalisé pour trouver le Kf équivalent qui minimise l’erreur-type entre les deux modèles.  Des courbes de la relation entre Ks et les valeurs optimales de Kf ont été générées pour une gamme de valeurs de Ks et de conditions de pompages représentées par le rapport du taux de pompage sur l’épaisseur de la lentille d’eau fraiche (Q/Bf).  Les valeurs optimales de Kf ont été par la suite mises à l’essai avec des modèles tridimensionnels.
Des différents scénarios de simulation, on a noté que la présence d’une intrusion saline n’affecte pas de façon significative le comportement des aquifères de sable fin (Ks <5 m/d), pour la pleine gamme des taux de pompage et d’épaisseurs de lentille d’eau fraiche considérées dans cette étude.  Dans les aquifères de sable moyen (10 < K_(s ) < 25 m/d), la présence d’une intrusion requière une conductivité hydraulique équivalente d’eau fraiche.


title:
This is my second test thesis
My second test thesis in French

contributor:
Royal Military College of Canada
Toomey, Sarah
Choi, Isaac

subject: Education Librarianship Feminism Careers

abstract: In French, .... This is a description of the thesis about education, librarianship, feminism and careers. This is a description of the thesis about education, librarianship, feminism and careers.


title: SOLDIERING ON: The Long-Term Effects of the Dieppe Raid on the 2nd Canadian Division

title: PERSÉVÉRANCE: Les effets persistants du raid de Dieppe à la 2e division canadienne

subject:
Dieppe raid
morale
training
junior leadership

abstract:
On 19 August 1942, the 2
nd
Canadian Division was nearly destroyed in Operation “Jubilee,” the
f
ailed Dieppe raid. The division’s next operations occurred two years later in the Normandy campaign (16
June
-
21 August 1944). Like Dieppe, the Normandy campaign had its share of failures, and the Canadian
effort there has long been seen as one of the wor
st performances among the Allied armies in the war.
Until now, no historian has asked whethe
r the 2
nd
Canadian Division suffered lingering effects from
Operation “Jubilee” that affected its performance in the Normandy campaign. Using primary source
documen
ts to examin
e the morale and training of 2
nd
Canadian Division and compare the “combat
effec
tiveness” of the 2
nd
and 3
rd
Canadian Divisions in the Normandy campaign, this study shows that
morale remained steady during the rebuilding p
eriod after Dieppe. Ho
wever, 2
nd
Canadian Division
underperformed during the Normandy campaign and suffered proportio
nally higher casualties than 3
rd
Canadian Division. Moreover, the division experienced problems with leadership and training, and
suffered two notable breakdowns
in unit cohesion that can be traced to the high number of junior leaders
lost in the Dieppe raid.


title: Canadians and 'Peacekeeping': An Analysis of Canadian Understanding of Peacekeeping and Canada's Involvement in Peace Support Operations Since 1991

title: Les Canadiens et « le maintien de la paix » : une analyse de la compréhension des Canadiens des opèrations de maintien de la paix et la participation Canadienne aux opèrations de soutien de la paix depuis 1991

subject:
Peacekeeping
Public Opinion
Political Sociology
Political Science
War Studies
Peace Support Operations
Peace Operations
United Nations

abstract:
Peacekeeping is frequently associated with Canadian identity and often referred to as a proud aspect of Canada’s history, but how much do Canadians really know about peacekeeping and peace support operations (PSOs), Canada’s involvement in them, and Canada’s and the CAF’s role in such operations? This research included an original survey and analysis of previous polls and studies to explore the extent to which Canadians were aware of the types of PSOs as defined by the UN and whether they see these operations as separate entities from merely peacekeeping, which speaks to Canadian understanding of the changing nature of conflict and PSOs. Furthermore, it explored the awareness of participants concerning the number of peacekeeping missions Canada has been involved in since the end of the Cold War and how Canadians see Canada’s and the CAF’s role in PSOs.
Pre-existing polls and surveys related to peacekeeping were examined and an original survey was conducted with over two hundred and fifty participants to explore their ability to answer PSO-related questions correctly and to gauge their perceptions of peacekeeping. It was found that statistically significant differences in responses between groups of participants existed, contingent on military service, as illustrated by using Chi-Square tests. The results also indicated that there is a delta between understanding of PSOs and Canada’s role compared to support for such missions. This work partially fills the gap in literature that exists concerning the perceived lack of awareness that Canadians have regarding the nature of PSOs today and the differences between those with and without military service vis-à-vis support levels and perceptions of PSOs, which to this point has been largely anecdotal.

abstract:
Les missions de maintien de la paix sont fréquemment associées à l’identité canadienne. Cet aspect de l’histoire militaire canadienne est souvent mentionné comme suscitant la fierté des citoyens. Or, qu’est-ce que les Canadiens savent vraiment des opérations de maintien et de soutien de la paix, de l’engagement du Canada à leur égard, et du rôle du Canada et des Forces armées canadiennes en leur sein? La présente recherche utilise une enquête originale et des sondages préexistants afin de faire la lumière sur le niveau de connaissance des Canadiens sur les différents types d’opérations de soutien de la paix, tel qu’entendu par l’Organisation des Nations Unies, sur la distinction entre ces missions et les opérations de maintien de la paix, et sur la nature changeante de ces opérations en situation de conflit. De plus, elle a cherché à déterminer la connaissance des Canadiens sur le nombre de missions de maintien de la paix auxquelles le Canada a participé depuis la fin de la Guerre froide, et de jauger l’interprétation qu’ont les Canadiens du rôle du Canada et des Forces armées canadiennes dans les opérations de soutien de la paix.
Le niveau de connaissance des Canadiens au sujet des opérations de soutien de la paix et leurs perceptions du maintien de la paix ont été explorées à l’aide de sondages préexistants et d’une enquête originale auprès de plus de deux cent cinquante participants. Des différences statistiquement significatives entre différents groupes de participants, selon qu’ils aient une expérience de service militaire ou non, illustrées par le test du Chi-carré. Les résultats ont aussi déterminé qu’il existait une différence delta entre la compréhension qu’ont les Canadiens de ces missions et le soutien qu’ils leur accordent. Cette recherche comble en partie une lacune dans la littérature existante concernant, d’une part, le manque perçu de connaissance des Canadiens sur la nature des opérations de soutien de la paix, et d’autre part, sur la différence de soutien et de perception des opérations de soutien de la paix entre les Canadiens ayant fait leur service militaire et ceux qui n’ont pas servi dans l’armée – un écart qui n’a été soulevé, jusqu’à maintenant, que de façon anecdotique.


title: THE USE OF BURNABLE NEUTRON ABSORBERS TO MITIGATE THE EFFECTS OF COOLANT VOIDING ON CANDU 37-ELEMENT FUEL

title: UTILISATION D’ABSORBEURS CONSOMMABLES DE NEUTRONS DANS LA GRAPPE DE COMBUSTIBLE CANDU À 37 CRAYONS POUR ATTÉNUER LES EFFETS DE LA FORMATION DE VIDE DANS LE CALOPORTEUR

subject: CANDU, burnable neutron absorbers, BNAF, 37-element fuel, LOCA, loss-of-coolant accident, CVR, coolant void reactivity, WIMS-AECL, RFSP-IST

subject: CANDU, absorbeurs consommables de neutrons, CANC (combustible avec absorbeurs consommables de neutrons), grappe de combustible à 37 crayons, APC, accident par perte de caloporteur, RFVC, réactivité associée à la fraction de vide du caloporteur, WINS-AECL, RFSP-IST

abstract: A study of the mitigating effects that burnable neutron absorbers have on coolant voiding in CANDU 37-element fuel was conducted. The purpose of this study was to determine if safety margins can be improved from the addition of small amounts of burnable neutron absorbers in the fuel through the simulation and analysis of a large loss of coolant accident. Burnable neutron absorbers Gd2O3, Eu2O3, and B2O3 have been shown to dampen the refuelling and plutonium transients with negligible impact on the fuel burnup. The lattice code WIMS-AECL was used to compute macroscopic cross sections which were passed to the diffusion code RFSP-IST to model a CANDU reactor undergoing a primary heat transport system reactor inlet header break. Combinations of burnable neutron absorbers Gd2O3, Eu2O3, and B2O3 were added to the CANLUB layer of specific fuel pins and core power distributions were computed for comparison against a natural uranium fuel case. Results show a reduction in the core enthalpy change when burnable neutron absorbers are added, along with a reduction in the side-to-side power oscillation during the transient. The reduction in the enthalpy change implies that the positive void reactivity experienced in CANDU reactors during the early phase of the loss of coolant accidents could be mitigated through the addition of burnable neutron absorbers in the fuel.

abstract: On a mené une étude sur les effets qu’ont les absorbeurs consommables de neutrons dans les grappes de combustible CANDU à 37 crayons sur l’atténuation de la formation de vide dans le caloporteur.  Le but de ce travail était de déterminer si l’on peut améliorer les marges de sûreté par l’ajout de petites quantités d’absorbeurs consommables de neutrons dans le combustible au moyen de la simulation et de l’analyse d’un accident par perte importante de caloporteur.  On a montré que les absorbeurs consommables de neutrons Gd2O3, Eu2O3 et B2O3 peuvent atténuer les phénomènes transitoires résultants du rechargement de combustible et du pic du plutonium tout en ayant un impact négligeable sur le burn-up du combustible.  Le code de réseau WIMS-AECL a été utilisé pour calculer les sections efficaces macroscopiques dont les valeurs étaient transmises au code de diffusion RFSP-IST afin de modéliser un réacteur CANDU subissant une rupture importante à l’entrée du système primaire de caloporteur.  Des combinaisons des absorbeurs consommables de neutrons Gd2O3, Eu2O3 et B2O3 ont été ajoutées à la couche de CANLUB pour des crayons de combustible spécifiques et les distributions de densités de puissance dans le cœur du réacteur ont été calculées et comparées à celle pour un réacteur n’utilisant que du combustible à uranium naturel.  Les résultats montrent une réduction de la variation de l’enthalpie du cœur lorsque l’on ajoute des absorbeurs consommables de neutrons. On constate aussi une réduction de l’oscillation latérale de la puissance durant la période transitoire.  La réduction observée de la variation de l’enthalpie implique que la réactivité positive due à la fraction de vide qui se produit dans les réacteurs CANDU durant la phase initiale des accidents de perte de caloporteur peut être atténuée par l’ajout dans le combustible d’absorbeurs consommables de neutrons.


title: Reducing Harmful Vibration of Rotary-Wing Aircrew Seats Using Magnetorheological Dampers.

title: Atténuation des vibrations de siège d’hélicoptère avec les amortisseurs magnetorheologiques.

subject: Magnetorheological MR Skyhook Semi-Active

abstract: The aim of this study was to investigate the use of magnetorheological (MR) dampers to protect rotary-wing aircrew from harmful vibration that exists in cockpits.  Four semi-active control policies were developed to vary the force provided by these dampers for a given excitation state. To simulate the proposed control schemes in conjunction with the dampers, the dampers were characterized through experimental excitation and fitted to a Bouc Wen model through parameterization. A CH-124 aircrew seat is examined and a suggestion for MR damper placements is postulated. The entire system is reduced to a sprung mass-damper system for use in simulations. A base excitation similar to that found in rotary-wing cockpits and an impact disturbance were used in the simulations and the resulting accelerations of the seat were compared to determine how well each controller attenuated the external force transferred to the aircrew seat. It was found that the controllers either marginally under-performed or equally-performed compared to a damper kept at a constant minimum input current during constant harmonic vibration tests, but outperformed the passive scenario when subjected to a sudden impact disturbance.

abstract: Le but de cette étude était d'étudier l'utilisation des amortisseurs a base magnéto-rhéologique (MR) afin de protéger l’équipage des hélicoptères contre les vibrations qui se produisent dans les cockpits. Quatre méthodes de contrôle semi-actif ont été développées. Afin de vérifier l’efficacité des méthodes de contrôle proposés, une étude expérimentale pour déterminer les paramètres d’un amortisseur a base magnéto-rhéologique  a été effectuée et un modèle mathématique basé sur le modèle de Bouc Wen a été développé. Le modèle de l’amortisseur a base magnéto-rhéologique et par suite utilisé avec un modèle de siège d'équipage d’un hélicoptère de type CH-124. Une excitation ayant des fréquences similaire à celles retrouvées dans les cockpits des hélicoptères ainsi que des perturbations externes ont été utilisées dans les simulations. Les accélérations du siège ont été comparé afin d’évaluer la performance de chaque méthode de contrôle et sa capacité de réduire les vibrations transmise à l’équipage.


title: FUELLING STUDY OF A CANDU REACTOR USING FUEL CONTAINING BURNABLE NEUTRON ABSORBERS

title: ÉTUDE DE L'ALIMENTATION D'UN RÉACTEUR CANDU AVEC DU COMBUSTIBLE CONTENANT D'ABSORBANTS DE NEUTRONS

subject:
CANDU
BURNABLE NEUTRON ABSORBER
REFUELLING POWER RIPPLE
FUELLING TRANSIENT
PLUTONIUM PEAK
CHANNEL POWER OPERATING MARGIN

abstract:
A fuelling study for a CANDU reactor was conducted using 37-element natural uranium (NU) fuel, augmented with burnable neutron absorbers to mitigate the effects of fuelling transients and improve power compliance margin during refuelling. The burnable absorbers of interest include Gd2O3 and Eu2O3. Various quantities of the two neutron absorbers are considered, and they are added homogeneously to the CANLUB coating of fuel bundles. The study was conducted to demonstrate the gain in operating margins of CANDU reactors incurred by implementing the neutron absorber containing fuel design.
The computer code Reactor Fuelling Simulation Program (RFSP) developed by the Canadian Nuclear Laboratories (CNL), previously Atomic Energy Canada Limited (AECL), was utilized to simulate the fuelling of the 480 channels, with each channel containing 13 fuel bundles. This is one of the CANDU reactor designs used in Ontario. Simulations were conducted for the 37-element NU fuel bundle design, with and without the neutron absorber modification to demonstrate the relative gain in margin incurred by the addition of burnable absorbers.
Fuel safety and performance are always important topics of consideration for nuclear utilities and regulatory bodies. The results of this study present improvements in the operating margin and the economy of neutrons for the considered CANDU reactor at the expense of a reasonably simple change to the fuel design.


title: BEHAVIOUR OF CANDU® FUEL AFTER A LOSS OF COOLANT ACCIDENT IN AN IRRADIATED FUEL BAY

title: COMPORTEMENT DU COMBUSTIBLE CANDU® À LA SUITE D’UNE PERTE DE CALOPORTEUR DANS LA PISCINE DE STOCKAGE DU COMBUSTIBLE ÉPUISÉ

subject:
Heat Transfer
Irradiated Fuel Bay
Nuclear Engineering
Spent Fuel Pool
COMSOL Multiphysics
Severe Accident

abstract:
After CANDU fuel is discharged from the reactor, it is submersed in large pools of water in Irradiated Fuel Bays (IFBs) to remove their decay heat.  It has been postulated that a large-scale drainage scenario i.e. Loss of Coolant Accident (LOCA) in an IFB could lead to a release of radioactivity if the fuel reaches temperatures sufficient for a runaway oxidation of the Zircaloy-4 sheathing.  The near miss at the Fukushima Diachii Spent Fuel Pools (SFPs) has prompted international efforts to better define the safety margins after irradiated fuel has been exposed to air.  The purpose of this work is to support the development of an IFB severe accident code, specifically for CANDU type nuclear generating stations.
A literature review and stress analysis of a fuel element were performed to determine the risk of overstraining and ballooning due to heat-up in a depressurized environment.  It was concluded that overstrains were possible for elements with extremely high fission gas release, but only after embrittlement of the sheath due to oxidation.  In the development of a severe accident code, defects arising from overstrain may be correlated to temperature to simplify the analysis.  If a mass failure of fuel sheaths is predicted, the effect of ballooning is expected to become significant.
In the concomitant analysis, the heat transfer behaviour of a 2-D bundle cross-section was simulated using COMSOL Multiphysics®.  Several sensitivity studies were completed at steady-state to explore the effects of ballooning, fuel-sheath gap size and fill gas composition on the maximum temperatures in the fuel.  It was shown the inclusion of conduction in the element’s interior enhanced heat transfer and resulted in slightly lower maximum temperatures.  Transient analyses were also completed to determine when oxidation (1) becomes a significant effect, and (2) is estimated to transition to linear reaction kinetics after which it may become self-sustaining.  The transition was predicted to occur within 2.6 hours for a 4 kW bundle, which could be considered as an upper bound for the heat generation produced by an exposed IFB bundle.  Therefore, due to the time required for heat up and the delay in the initiation of breakaway, it was indicated that sufficient margin exists for operators to intervene before a passively cooled, isolated bundle undergoes a breakaway reaction.
The cumulative effect of neighbouring bundles has the potential to adversely impact the heat dissipation process.  Scaling up to a full-scale CANDU IFB or even IFB rack is difficult due to the complex bundle geometry and open rack design. In the last part of this work, a process to predict the steady-state temperature and mass fluxes of air as it passes through a rack of spent fuel using analytical models and computational fluid dynamics (CFDs) techniques is presented. The scenario acts as a lower bound estimate for the temperatures expected during a complete loss of coolant in a fuel bay by examining the 3-D heat-up of a stand-alone quarter rack without flow resistance of the bundles. The correct incorporation of flow resistance, in a detailed convection model that can be validated by experiment, is a necessary step before conclusions could be made about the safety of IFBs.  However, the analysis as summarized in Section 8, using a CFD model for a 0.35 MW fuel rack, indicates that the maximum temperature of the air within the rack was about 575 K and located at the centre of the outlet.  This result is encouraging to support the safety of IFBs, as the temperature is well below that required for a breakaway reaction.


title: Creation of a 22Na and 7Be global data set for use as an atmospheric tracer and radiochronometer

title: Création d'un ensemble de données globales du 22Na et du 7Be pour utilisation en tant que traceur atmosphérique et radiochronomètre

subject:
radionuclides
cosmogenic
atmospheric circulation
aerosol

abstract:
Cosmogenic radionuclides often serve as environmental tracers, tracking both the timing and pathway of pollutants and other materials in the environment. Radionuclides with significantly different half-lives (𝑡1/2), such as 7Be (𝑡1/2 = 53.22 d) and 10Be (𝑡1/2 = 1.51 × 10^6 year), are commonly used as tracers, given their ability to function as a radiochronometer. Changes in the relative concentrations of these two radionuclides provide timing information on environmental processes, such as atmospheric circulation processes. However, the relatively high cost and specialized nature of equipment needed to measure 10Be, due to its long half-life, are significant barriers to its widespread use.
This thesis investigates the use of 22Na (𝑡1/2 = 2.6027 year) as an alternative to a 10Be based radiochronometer. Given its low production rate, 22Na, is seldom measured with ground-level aerosol samplers, except under special atmospheric conditions. Spectral summation, the process of summing spectra from consecutive aerosol samples, was developed through this work as a new technique to quantify 22Na and allow for its use as a tracer. Furthermore, quantification was improved over several previous studies of 22Na by incorporating True Coincidence Summing (TCS) correction factors in the calculations of activity concentration.
The new spectral summation technique was evaluated using 7 d and 30 d intervals.  The 30 d interval performed better and was used to generate the first TCS-corrected multi-year global data set of 22Na and 7Be activity concentrations. Validation of the 22Na data set was performed by statistical comparisons between data derived from the summation technique and that from previous non-summation analyses for 7Be.  The data were examined in the context of a semi-empirical model that incorporated both production and atmospheric transport components, leading to the conclusion that atmospheric transport was the dominant factor in ground-level 22Na concentrations. It is anticipated that this spectral summation technique will be useful in other studies involving low-activity radionuclides and that the 22Na data set will be valuable for future studies involving atmospheric circulation, both within and beyond the domains of meteorology and climatology.

abstract:
Les radionucléides cosmogéniques servent souvent de traceurs environnementaux, traçant le moment ainsi que la trajectoire de matières polluantes et d’autres matériaux dans l’environnement. Les radionucléides dont les demi-vies diffèrent de façon significative, tels que le 7Be (𝑡1/2 = 53.22 d) et le 10Be (𝑡1/2 = 1.51 × 106 année), sont communément utilisés comme traceurs à cause de leur capacité de fonctionner comme radiochronomètres. Les changements des concentrations relatives de ces deux radionucléides procurent de l’information temporelle sur les processus environnementaux tels que les processus de circulation dans l’atmosphère. Cependant, le coût relativement élevé et la nature spécialisée de l’équipement nécessaire pour la mesure du 10Be, à cause de sa longue demi-vie, représentent des obstacles importants pour son application répandue.
Cette thèse étudie l’emploi du 22Na comme alternative pour un radiochronomètre basé sur le 10Be. Le 22Na, à cause de son faible taux de production, est rarement mesuré par des échantillonneurs d’aérosols au niveau du sol, sauf dans des conditions atmosphériques spéciales. Une méthode de sommation spectrale qui est un procédé d’addition de spectres obtenus d’échantillons d’aérosols consécutifs, mise au point pour ce travail est une nouvelle technique pour quantifier le 22Na et permettre son utilisation comme traceur. De plus, la quantification a été améliorée par rapport à plusieurs études précédentes du 22Na par l’incorporation de facteurs de corrections dits de Sommation de Vraies Coïncidences (SVC) dans les calculs des concentrations d’activité.
La nouvelle technique de sommation spectrale est évaluée pour des intervalles de 7 d et de 30 d. La technique basée sur des intervalles de 30 d a donné de meilleurs résultats et a été utilisée pour générer la première base de données globale multi-années avec la correction SVC pour les concentrations d’activité de 22Na et de 7Be. La validation de la base de données du 22Na a été effectuée par des comparaisons statistiques entre les données obtenues par la technique de sommation et celles obtenues d’analyses précédentes du 7Be non-basées sur la sommation. Les données ont été examinées dans le contexte d’un modèle semi-empirique qui incorpore les composantes de la production et du transport atmosphérique, menant à la conclusion que le transport atmosphérique était le facteur dominant des concentrations de 22Na au niveau du sol. À ce que cette technique de sommation spectrale va devenir utile pour d’autres études impliquant des radionucléides de faibles activités et la base de données du 22Na pourra servir à des études futures sur la circulation atmosphérique, domaines de la météorologie et de la climatologie, et au-delà.


title: Elucidating a Biosynthetic Pathway for Arsenobetaine in Higher Terrestrial Fungi

title: À la quête d’une voie biosynthétique de l’arsénobétaïne dans les champignons supérieurs terrestres

subject:
arsenic
arsenobetaine
fungus
biotrasformation
mycelium
fruiting body
microbial community
biosynthetic pathway

abstract:
The toxicity of arsenic is greatly dependent on its chemical form and only one arsenic compound is considered to be non-toxic, arsenobetaine (AB). The formation pathway for AB is still unknown despite being found in high concentrations and proportions in many marine organisms. AB is found in fewer organisms and at lower concentrations and proportions in the terrestrial environment with the exception of the fruiting bodies (FBs), or mushrooms, of terrestrial fungi. The present study interrogated AB formation pathways in the complete fungal organism (fungus and associated microbes) through a combination of fruiting body and substrate analysis, and culture experiments. The analytical methods used were reviewed and selected to include complementary high performance liquid chromatography – inductively coupled plasma mass spectrometry (HPLC-ICP- MS) and X-ray absorption spectroscopy (XAS), specifically x-ray absorption near edge structure (XANES) and XAS 2-dimensional imaging.
A comprehensive survey of arsenic compounds in the mushrooms of 46 different fungus species over a diverse range of phylogenetic groups were collected from Canadian grocery stores and background (sites with lower arsenic concentrations) and arsenic-contaminated areas. The major arsenic compounds in mushrooms were found to be similar among phylogenetic groups, and AB was generally absent in log-growing mushrooms, suggesting the microbial community may influence arsenic speciation in mushrooms. The high proportion of AB in mushrooms with puffball or gilled morphologies may suggest that AB acts as an osmolyte in certain mushrooms to help maintain fruiting body structure. The mycelia of three different fungi species (targeting those containing AB, including Agaricus bisporus) were cultured axenically and exposed to AB, arsenate (As(V)) and dimethylarsinoyl acetic acid (DMAA, a potential AB precursor) for 60 days. The mycelia of all fungi species accumulated all arsenic compounds with two species (those whose fruiting bodies contain mostly AB) accumulating significantly more AB than other compounds, but few biotransformations were observed. Thus AB biosynthesis by fungus mycelium is unlikely. To investigate the involvement of reproductive life stage of Agaricus species (an AB-containing fungus) in AB formation growth substrate and fungi were collected and analyzed during the commercial growth of A. bisporus.  AB was found to be the major arsenic compound in the fungus at the earliest growth stage of fruiting (the primordium). AB was revealed by two-dimensional imaging to be present only in fungal tissue and not in embedded substrate of an A. bisporus primordium grown on As(V) treated substrate, and in a mature A. campestris fruiting body stalk from arsenic contaminated mine tailings. These findings indicate AB formation is likely associated with the reproductive life stage of the fungus. To interrogate the contribution to AB formation of the microbial communities associated with mushrooms, 16s pyrosequencing techniques were used to reveal that phyla diversity in the growth material for the commercial cultivation of A. bisporus increased at the time of FB initiation, coinciding with the appearance of AB. Microbial communities from similar locations were found to have similar microbial structures, but were different between log materials and soil substrates. Ten bacteria species associated with FB initiation and AB containing FBs did not transform As(V), dimethylarsinic acid (DMA) and DMAA under axenic culture. Similarly a consortia of microbes isolated from FB-associated soil did not produce AB. Overall, AB formation appears to be associated with the reproductive life stage of the fungus and likely involves a combination of organisms, perhaps those symbiotically associated with each other.

abstract:
Le niveau de toxicité de l’arsenic dépend largement de sa forme chimique, et un seul composé d’arsenic, l’arsénobétaïne (AB), est considéré non-toxique. Bien que l’AB existe en concentrations et proportions élevées dans plusieurs organismes marins, son mécanisme de synthèse demeure inconnu. En milieu terrestre, l’AB se trouve en plus faibles concentrations et proportions, à l’exception des fructifications, ou champignons, d’organismes fongiques terrestres. Le présent ouvrage a examiné les voies de synthèse de l’AB dans l’organisme fongique complet (qui inclut à la fois le champignon et les microbes qui y sont associés) par le biais d’analyses des fructifications (les fruits du champignon) et des substrats, ainsi que par des expériences de cultures champignonnières. Diverses méthodes d’analyse ont été évaluées et les méthodes complémentaires suivantes ont été retenues : chromatographie liquide à haute performance – spectrométrie de masse avec plasma à couplage inductif (CLHP-SM-PCI), et spectroscopie par absorption de rayons-X (SAX), plus particulièrement la spectroscopie de structure près du front d’absorption de rayons-X (SSPAX), et l’imagerie en deux dimensions de la SAX.
Un relevé exhaustif des composés d’arsenic se trouvant dans les champignons de 46 espèces d’organismes fongiques différents couvrant un vaste éventail des groupes phylogénétiques a été complété à partir de spécimens provenant de supermarchés canadiens, de sites de référence (où les concentrations d’arsenic sont faibles), et de régions contaminées à l’arsenic. Les principaux composés d’arsenic dans les champignons sont similaires parmi les groupes phylogénétiques, et l’AB est généralement absent chez les champignons qui poussent sur des troncs d’arbres, ce qui suggère une influence de la communauté microbienne dans la spéciation de l’arsenic par le champignon.  Les grandes proportions d’AB dans les champignons de morphologies charnue ou lamellée peuvent suggérer que l’AB joue un rôle osmotique dans le maintien structurel de la fructification. Les mycéliums de trois différentes espèces d’organismes fongiques (choisies parmi celles qui contiennent de l’AB, dont l’Agaricus bisporus) ont été cultivés en milieu axénique et exposé à l’AB, à l’arséniate (As(V)) et à l’acide acétique de diméthylarsinoyle (AADM, un précurseur potentiel de l’AB) durant une période de 60 jours. Ces composés d’arsenic ont été accumulés dans le mycélium de chaque espèce de champignon, et deux de ces espèces (celles dont les fructifications contenaient principalement de l’AB) ont accumulé une plus grande quantité d’AB que les autres composés (de façon significative), mais comportant peu de biotransformations. Il est donc peu probable que le mycélium fongique procède à la biosynthèse de l’AB. Pour enquêter sur la synthèse de l’AB durant le cycle de reproduction des espèces Agaricus (champignons contenant de l’AB), des échantillons de substrat et de champignons ont été prélevés et analysés au cours de la croissance de A. bisporus en production commerciale. Le composé d’arsenic principal s’est avéré être l’AB dans le champignon au tout début de son cycle de fructification (étape primordiale). Une analyse par imagerie en deux dimensions a révélé que l’AB ne se trouve que dans la matière fruitière et non dans les composantes du substrat d’un thalle primordial de A. bisporus dont le substrat a été imprégné d’As(V), ainsi que dans la tige d’un champignon A. campestris ayant complété sa croissance dans des résidus miniers contaminés à l’arsenic. Ces résultats indiquent que la formation de l’AB est probablement associée au cycle de reproduction des champignons. Des techniques de pyroséquençage 16s ont été employées fin d’élucider la contribution de l’AB à la formation des communautés microbiennes associées aux champignons. Celles-ci ont révélé que, dans le substrat de croissance utilisé en culture commerciale du A. bisporus, la diversité phylétique est plus importante à l’amorce de la fructification, ce qui coïncide avec l’apparition de l’AB. Les communautés microbiennes de milieux similaires se ressemblent, et sont différentes des communautés associées aux troncs d’arbres et aux substrats de terre. Des dix espèces bactériennes associées à l’initiation de la fructification et à des organismes fongiques contenant de l’AB, aucune n’a transformé l’As(V), l’acide diméthylarsinique (ADMA), ou l’AADM en culture axénique. De même manière, un consortium microbien isolé des sols associés à la fructification n’a pas produit d’AB. En fin de compte, il semble que la synthèse d’AB soit liée au cycle de reproduction champignons et implique probablement une combinaison d’organismes, dont certains fonctionnent en association symbiotique.


title: Analyzing the Three-Dimensional Deformation Behaviour of an Empty CANDU Fuel Bundle Using the Finite Element Method

title: Analyse du Comportement de la Déformation Tridimensionnelle d’une Grappe de Combustible CANDU Vide à l'aide de la Méthode des Éléments Finis

subject:
Finite Element Analysis
Finite Element modelling
CANDU
fuel bundle
off-normal conditions
bowing
fuel bundle sag

abstract:
During off-normal or accident conditions, a CANDU fuel bundle may be subjected to thermal and mechanical loads when it is heated above its normal operating temperature. In these conditions, the fuel elements may deform due to two mechanisms: bowing of the fuel elements due to changes in mechanical properties caused by thermal gradients and sagging of the fuel elements under their self-weight. The resulting deformation may impede heat transfer from the fuel elements to the coolant and exacerbates the cooling of the bundle. Therefore, it is important to understand and quantify the conditions under which the fuel bundle will sufficiently deform such that the coolant flow distribution and the ability of the coolant to cool the fuel is not adversely impacted.
A model capable of predicting the fuel performance and the 3-D deformation of a full bundle has not been developed yet. This thesis presents a detailed 3-D deformation model of an empty fuel bundle in order to set the stage for the development of such a model. The bundle deformation model presented in this work is capable of simulating the sag of the elements and the end-plates, differential thermal expansion of the bundle, fuel element bowing, and creep deformation of the bundle. The deformation results were validated against experimental data, which were made available for the first time for simulation purposes by Canadian Nuclear Labs (CNL). The results show good agreement with the experimental results, indicating that the model was able to capture the overall trends observed in the experiment. The feasibility of a bundle deformation model which includes contact between adjacent elements, non-uniform temperature gradients, and creep deformation at off-normal condition was  demonstrated.

abstract:
En cas de conditions accidentelles, une grappe de combustible CANDU peut être soumise à des charges thermiques et mécaniques lorsqu'elle est chauffée au-delà de sa température normale de fonctionnement. Dans ces conditions, les éléments de combustible pourraient se déformer selon deux mécanismes: la flexion des éléments de combustible à cause des changements de propriétés mécaniques provoqués par des gradients thermiques, et l'affaissement des éléments de combustible sous leur propre poids.  La déformation résultante peut restreindre le transfert de la chaleur des éléments de combustible vers le caloporteur et nuire au refroidissement de la grappe. Il est donc nécessaire de comprendre et de quantifier les conditions dans lesquelles la grappe de combustible se déforme suffisamment afin que la distribution du flux de caloporteur et sa capacité à refroidir le combustible nucléaire ne soient pas affectées négativement.
Un modèle capable de prédire la performance du combustible et la déformation 3-D d'une grappe entière n'a pas encore été développé. Cette thèse présente un modèle de déformation 3-D détaillé d'une grappe de combustible vide afin de préparer la voie pour le développement d'un tel modèle. Le modèle de déformation présenté dans ce travail est capable de simuler l'affaissement des crayons de combustible et des plaques d'extrémité, la dilatation thermique différentielle de la grappe, l'inclinaison des éléments de combustible et la déformation par fluage de la grappe. Les résultats de la déformation ont été validés en comparant avec des données expérimentales qui ont été mises à disposition pour la première fois pour les besoins de la simulation par les Laboratoires Nucléaires Canadiens. Les résultats montrent un bon accord avec les résultats expérimentaux. Ceci indique que le modèle a correctement prédit les tendances globales observées dans l'expérience. On a démontré la faisabilité d'un modèle de déformation d’une grappe qui inclut le contact entre des éléments adjacents, des gradients de température non uniformes et une déformation par fluage dans des conditions accidentelles.


title: Methane + Propane Mixed Gas Hydrate Studies Using the 3-in-1 Technique

title: Études d'Hydrates de Gaz d'un Mélange de Méthane + Propane en Utilisant la Technique 3-en-1

subject:
Gas Hydrates
binary mixtures
methane
propane
Hydrate Morphology
Growth Kinetics
Phase Equilibria

abstract:
The 3-in-1 technique was applied to hydrates of binary mixtures of methane + propane (90:10 and 98:2 mole ratios). Hydrate morphology showed a strong dependence on subcooling. Three groups of crystal habits were identified: below 1.5 K subcooling, the dominant habit was elongated polyhedral crystals; between
subcoolings of 2.0 to 3.0 K, a granular habit dominated the morphology, with more rounded polyhedral crystals embedded in the crystal  lm. Towards 3.5 K and higher subcoolings, the hydrate  lm was smoother, and individual granules became indistinguishable. Single polyhedral crystals within the  lm were smaller, and indistinguishable at subcoolings higher than 5.0 K. These differences in morphology suggest growth mechanisms strongly dependent on driving force. The habit of single crystals closely resembled that of the  lm, but their morphologies diverged with increasing subcooling. Individual crystals sometimes detached from the main  lm and grew independently and with different morphologies than that of the  lm. Conversely, single crystals that had grown independently from the main  lm attached to and assumed the  film morphology. These observations suggest at least two growth mechanisms could present at once during hydrate growth. Regardless of driving force, growing crystals were observed to partially dissociate and reform as the clathrate  lm grew. This phenomenon could be due to instability of some crystals that transform into their most stable form. Another explanation could be local gradients of guest concentration in the liquid phase that could cause the dissociation. Hydrate-liquid-vapor equilibrium temperatures were measured with minimum uncertainties and agreed with those reported in literature for the studied systems. Growth rates showed a strong dependence on
subcooling and could be measured under several degrees of subcooling with a single gradient experiment. Growth rates of single crystals and the hydrate  film were similar at lower driving forces and diverged when subcooling was higher than 2.5 K. These differences in growth rates provide evidence of the onset of different mechanisms and could explain the observed changes in crystal habit with driving force. The 3-in-1 technique was shown to be a precise, multifaceted tool to evaluate hydrates from binary gas mixtures, that provides visual evidence of complex crystal growth mechanisms occurring during their crystallization.

abstract: La technique 3-en-1 a été appliqée aux hydrates de mélanges binaires de méthane + propane (rapports molaires 90:10 et 98:2). La morphologie des hydrates présente une forte dépendance au sous-refroidissement. Trois groupes d'habitus cristallin ont été identifiés: en dessous de 1.5 K, l'habitus était dominée par des cristaux polyédriques allongés; Entre les sous-refroidissements de 2.0 à 3.0 K, un habitus granulaire dominait la morphologie, avec des cristaux polyédriques plus arrondis noyés dans le film cristallin. Vers 3.5 K et plus de sous-refroidissement, le film d'hydrate était plus lisse et les granules individuels devenaient indiscernables. Les cristaux simples polyhèdraux dans le film étaient plus petits et impossibles à distinguer aux sous-refroidissements supérieurs à 5.0 K. Ces différences de morphologie suggèrent des mécanismes de croissance fortement dépendants de la force motrice. L'habitus des mono-cristaux ressemblait beaucoup à celle du film, mais leurs morphologies divergeaient avec l'augmentation du sous-refroidissement. On a observé que les cristaux se détachent du film et se développent en différentes morphologies. Inversement, certains mono-cristaux sont fixés au film d'hydrate et se développent dans la morphologie du film. Ces observations suggèrent qu'au moins deux mécanismes de croissance pourraient se présenter simultanément lors de la croissance des hydrates. Indépendamment de la force motrice, on a observé que les cristaux en croissance se dissociaient et se reformaient constamment à mesure que le film de clathrate se développait. Ce phénomène pourrait être dû à l'instabilité de certains cristaux qui se transforment en leur forme la plus stable. Une autre explication pourrait être les gradients locaux de concentration dans la phase liquide qui pourraient provoquer la dissociation. Les températures d'équilibre hydrate-liquide-vapeur ont été mesurées avec un minimum d'incertitudes et conformes à celles rapportées dans la littérature pour les systèmes étudiés. Les taux de croissance montraient une forte dépendance vis-à-vis du sous-refroidissement et pouvaient être mesurés sous plusieurs degrés de sous-refroidissement avec des expériences à un seul gradient. Les taux de croissance des monocristaux et du film d'hydrate sont similaires lorsque les forces motrices sont faibles et divergent lorsque le sous-refroidissement est supérieur à 2.5 K. Ces différences dans les taux de croissance témoignent de l'apparition de mécanismes différents et pourraient expliquer les changements observés dans le comportement cristallin avec la force motrice. La technique 3-en-1 s'est révélée être un outil précis et multiforme permettant d'évaluer les hydrates issus de mélanges de gaz binaires et de fournir une preuve visuelle des mécanismes complexes de croissance des cristaux se produisant pendant leur cristallisation.


title:
Test Thesis 20210726 1 edited
Test Thesis 20210726 1

contributor:
RMC
superlast, superfirst
cosuperlast, cosuperfirst

format: application/pdf application/pdf

subject: Keywords

abstract: test


title: Geotechnical Centrifuge Modelling of Contaminant Transport through Frozen Soil

title: Modélisation par Centrifugeuse Géotechnique de Transport de Contaminants dans des Sols Gelés

subject:
Cold Regions
Contaminant Transport
Geotechnical Centrifuge Modelling
Petroleum Hydrocarbons
Frozen Soil
Physical Modelling

abstract:
Permafrost degradation due to climate change is a threat to the Canadian Arctic. A long-standing practice in cold regions is to use permafrost to contain contaminated soil because it was thought to be impermeable. Although not fully impermeable, frozen soil has been a reasonable containment option. However, the degradation of permafrost could lead to the release of previously contained contaminants, threatening the local ecosystems and communities. It is important to understand how contaminant transport will occur in a northern environment compared to temperate regions. The long-term study of contaminant transport is often a complex and expensive endeavour due to the isolation of most contaminated sites, the resources required and the short field season in the Arctic.
	Geotechnical centrifuge modelling is one solution to the cost and complexities involved in performing in-situ field studies. With the scaling principles by which it is governed, centrifuge modelling has proven to be an effective tool to conduct research by simulating the behaviour of large-scale phenomena using benchtop sized models. The scaling effect of time also allows for the conduct of multiple experiments in a relatively short amount of time that simulates the behaviour of a prototype site over a long period of time.
	The use of geotechnical centrifuge modelling for contaminant transport research was validated by conducting a modelling of models. Three centrifuge contaminant transport experiments were conducted at different acceleration ratios and another experiment was conducted in an acrylic column. Pumpkin seed oil was used as the contaminant for all experiments. The experiments proved that the scaling principle for the wetting front velocity of the oil was being followed, thereby validating the use of the centrifuge for contaminant transport research.
	Centrifuge experiments were also conducted to observe and quantify the effects of moisture content on the advective and diffusive transport of the oil. The presence of moisture within the soil slowed the migration of the oil. Experiments with frozen soil were conducted to observe and quantify the effects of temperature on the migration of the oil. Decreased temperatures reduced the wetting front velocity of the oil due to the increased surface tension of the oil at lower temperatures. A centrifuge experiment was conducted with soil from an abandoned barrel cache on Ellesmere Island, NU. The wetting front velocity of the oil into the Arctic soil was calculated.
The results of this research demonstrate that the transport of contaminants through soil at contaminated sites can be calculated using centrifuge experiments. This would help to identify the contaminant source zone and plume based on the moisture conditions, soil, contaminant and recent climate of the site, thus increasing the effectiveness of remediation efforts.

abstract:
La dégradation du pergélisol causé par les changements climatiques est un risque pour l’arctique Canadien. Une technique courante pour encapsuler du sol contaminé est l’utilisation du pergélisol puisqu’il est quasiment imperméable. La dégradation du pergélisol pourrait mener à la mobilisation de contaminants qui étaient immobilisés par le pergélisol. La recherche à long-terme de sites contaminés est très complexe et coûteuse en raison de l’isolation des sites, des ressources requises et de la courte période annuelle favorable pour la recherche dans le Nord.
	La modélisation par centrifugeuse géotechnique est une solution aux coûts et aux complexités de la recherche à long-terme sur un site contaminé. Les principes d’échelle de la modélisation par centrifugeuse permettent l’étude du comportement de prototypes à grandes échelle avec des modèles de petite taille. Les principes d’échelle permettent la conduite de plusieurs essais dans un court délai qui simulent le comportement à long-terme d’un site prototype.
	La validation de l’utilisation d’une centrifugeuse pour la recherche sur le transport de contaminants a été faite avec une modélisation de modèles. Trois essais ont été effectués dans la centrifugeuse à des accélérations différentes et un autre dans une colonne. De l’huile de graines de citrouille a été utilisée comme contaminant pour tous les essais. Les essais de validation ont prouvé que le principe d’échelle pour la vitesse d’infiltration est respecté. L’utilisation d’une centrifugeuse pour la recherche de transport de contaminant a été validée.
	Plusieurs essais avec la centrifugeuse ont été effectués afin d’observer et de quantifier l’effet de la teneur en eau sur l’infiltration de l’huile dans le sol. Il a été observé qu’une augmentation de teneur en eau réduit le taux d’infiltration. Des essais avec du sol gelé ont aussi été effectués afin d’observer et quantifier l’effet de la température sur le taux d’infiltration. Les températures sous le point de congélation ont réduit le taux d’infiltration de l’huile. Ceci est causé par l’augmentation de la tension superficielle entre l’huile et les grains de sols à basse température.
	Un essai a été effectué avec des échantillons de sol d’une cache de barils situé dans l’Arctique canadien sur Île d'Ellesmere, NU. Le taux d’infiltration de l’huile dans le sol arctique a été calculé. Les résultats de cette recherche ont prouvé que le taux d’infiltration des contaminants dans le sol du site contaminé peut être déterminé avec ces essais de centrifugeuse. Ceci aiderait à identifier la zone contaminé sous la surface du sol dépendant de la teneur en eau, du sol, des contaminants et le climat du site. Connaissant l’étendue de la zone contaminé aide à optimiser les efforts d’assainissement des sites contaminés dans l’Arctique canadien.


title: PROBABILITY OF DETECTION FOR PULSED EDDY CURRENT INSPECTION OF SECOND LAYER CRACKS IN AIRCRAFT LAP-JOINT STRUCTURES

title: PROBABILITE DE DETECTION PAR UNE METHODE DE COURANTS DE FOUCAULT PULSES DE LA SECONDE COUCHE STRUCTURALE D’UN JOINT A RECOUVREMENT DANS UN ENGIN AERIEN

subject:
Probability of Detection
Pulsed Eddy Current
Non-destructive Testing

abstract:
A thesis completed by Uemura, Cole Omega, in partial fulfilment of the requirements for a Master of Science in Physics from the Royal Military College of Canada on this 24th day of January, 2018, on Probability of Detection for Pulsed Eddy Current Inspection of Second Layer Cracks in Aircraft Lap-Joint Structures, under the direction of Dr. Thomas Krause.
Conventional eddy current testing is a non-destructive technique used extensively within the aerospace industry to detect surface and near surface defects in structures of aluminum aircraft components. Aging aircraft such as the CP-140 Aurora and CC-130 Hercules are susceptible to cyclic fatigue cracks at bolt hole locations in multi-layer aluminum lap-joint structures. Conventional bolt hole eddy current (BHEC) inspection techniques, however, require fastener removal to detect second layer cracks. A pulsed eddy current (PEC) technique has demonstrated the ability to detect second layer cracks without fastener removal. The probe design for this technique consists of a ferrite core surrounded by four pairs of differentially connected pick-up coils, which utilizes the ferrous fastener as a flux conduit, inducing eddy currents at greater depths within the material. The transient signal response is analyzed using modified principal components analysis (MPCA) to produce scores, which are then processed using cluster analysis. Since a large number of representative blank fastener signals are required to accurately assess the reliability of this inspection technique in the absence of in-service samples, a series of simulations was conducted using cluster analysis and the smallest half volume (SHV) analysis methodology. A probability of detection (POD) analysis of the PEC inspection technique is then performed, including the metric required, in the form of an 𝑎90/95 value, to assess its reliability for the detection of second layer cracks at ferrous fasteners in aircraft lap-joint structures. Based on both the measured and simulation results obtained in this thesis work, it is determined that an 𝑎90/95 value of 2.0 mm (0.08 inch) is associated with this PEC inspection technique. The average detection and false call rates obtained for the simulations are 93% and 11%, respectively, confirming a blind outlier detection capability. This research confirms an 𝑎90/95 value for PEC that approaches that for BHEC (0.05 inch), but with only up to 15% of the fasteners being removed, as opposed to removal of 100% of the fasteners for BHEC. The numerous advantages to the PEC inspection method are that 1) it does not require fastener removal, hence minimizing collateral damage on the surface structure, 2) reduces the cost associated with labour and human resources, and 3) shortens aircraft maintenance downtime. These results provide assurance that the PEC technique is capable of detecting second layer cracks in aircraft lap-joint structures with high confidence, reliability, and detectability.

abstract:
Thèse complétée par Uemura, Cole Omega, pour l’obtention d’une maitrise en science en physique au collège militaire royal du Canada ce 24 janvier 2018 sur la probabilité de détection par une méthode de courants de Foucault pulsés de la seconde couche structurale d’un joint à recouvrement dans un engin aérien, sous la direction de Dr Thomas Krause.
La méthode par évaluation non-destructive par courants de Foucault est largement répandue dans le domaine de l’industrie aérospatiale afin de déceler des défauts de la couche superficielle dans les composantes en aluminium d’un engin aérien. Les engins ayant plus d’années d’usure tels l’Aurora CP-140 et Hercules sont vulnérables aux fatigues cycliques près des trous de boulons dans le laminage en aluminium des joints à recouvrement. La méthode usuelle par courants de Foucault (MUCF) utilisées pour évaluer les trous des boulons nécessite le retrait des points d’attache. On a démontré que la méthode par courant de Foucault pulsée(CFP) pouvait déceler des fissures à la seconde couche sans avoir à enlever les points d’attache. La sonde de détection est un matériau de ferrite ayant quatre paires de bobines détectrices proche voisines qui sont branchées en mode différentiel. Ces bobines sont sensibles aux flux magnétiques induit dans les attaches fabriquées d’un matériau magnétique permanent au travers duquel un courant est induit. La réponse en régime transitoire est analysée par le truchement de l’analyse en composante principale modifiée(ACPM) qui nous donne un pointage et qui nous fournit ensuite une analyse de groupe. Puisque qu’un grand nombre de signaux sont nécessaires afin d’obtenir une évaluation fiable afin de mieux comparer avec des échantillons en service, une série de simulations fut dirigée pour estimer l’analyse de groupe ainsi qu’une analyse du plus petit demi-volume(PPDV). L’analyse de la
vi
probabilité de détection(POD) de la méthode par CFP fut ensuite menée en se basant sur un critère spécifié sous la forme de a90/95, qui permet d’évaluer la fiabilité d’une détection de fissure à la seconde couche d’une attache en ferrite dans un joint à recouvrement d’un engin. En se basant sur les résultats et simulations obtenues dans notre étude, il est recommandé qu’une valeur de a90/95 égale à 2.0 mm (0.08 pouce) soit associée à cette méthode par CFP. Les taux moyens de détection et d’erreur lors de nos simulations étaient de 93% et 11% respectivement, ce qui confirme une capacité nette de bien détecter. Dans ce mémoire, nous montrons que la valeur de a90/95 pour les CFP est proche de celle obtenue pour les MUCF (0.08 pouce). Ceci voudrait dire que seulement 15% des attaches devraient être enlevées au lieu de 100% pour l’évaluation par MUCF. L’avantage est que l’évaluation par CFP n’implique pas le retrait de tous les points d’attache et ainsi minimise les dommages à la surface d’une structure, réduit les coûts de main d’oeuvre et diminue le temps de l’entretien. Les résultats obtenus sont concluants et nous permettent d’affirmer que la méthode par CFP est très performante lors de l’évaluation de la seconde couche de défauts dans les joints à recouvrement en ce qui a trait à la confiance élevée de détection ainsi qu’à la fiabilité.


title: Axe-lerator: Designing an entrepreneurial living learning program for Acadia University

type: Text Dissertation/Thesis

contributor:
Sproule, Samantha H. (author)
(MacNeil, Ryan) (Thesis advisor)
Acadia University (Degree grantor)

rights: The author grants permission to the University Librarian at Acadia University to reproduce, loan or distribute copies of my thesis in microform, paper or electronic formats on a non-profit basis. The author retains the copyright of the thesis.

subject: LE3 .A278 2017

abstract: The major objective of this study is to provide the information to create an entrepreneurial residence on the Acadia University campus, Wolfville, Nova Scotia. This study uses the direct, practical, and applied methods of design science research in a storytelling format to communicate the findings. Information presented includes an evaluation of the application domain (the entrepreneurial ecosystem at Acadia University) where interviews and focus groups were conducted to obtain information; a review of the existing living learning program and entrepreneurship incubator and accelerator literature; and a content analysis of the existing entrepreneurship and innovation residence websites. In conclusion, this report provides a recommendation of features to include in an entrepreneurial residence, with emphasis on the necessity to continue evaluating and building the product to fit the needs of the student entrepreneurial customer base.


title: Evaluation of biomarkers of arsenic exposure from well water in two rural Nova Scotian communities

contributor:
Cull, Kathryn (author)
(Murimboh, John) (Thesis advisor)
(Stanley, Cliff) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2011

abstract: Well water is one of the most common sources of chronic exposure to inorganic arsenic, a recognized human carcinogen. Rural well waters in Nova Scotia have amongst the highest arsenic concentrations in Canada, in part due to the natural enrichment from the local bedrock and soils. In order to assess whether arsenic concentrations in well water are a principle exposure hazard, the arsenic concentrations of well waters were compared with human urine, hair, fingernail, and toenail biomarkers using a minimum hypergeometric probability (MHP) statistical method. Samples were collected from wells (108) and participants (179) in Waverley and Hubbards, Nova Scotia. Speciation of arsenic by high performance liquid chromatography – inductively coupled plasma – mass spectrometry indicated that As(V) was the dominant species in most well water samples. Arsenobetaine and DMA(V) were the most common species in urine, indicating that the metabolism of arsenic may be more complicated than previously reported. The MHP for each biomarker was identified using a range of well water arsenic concentration thresholds. Elevated concentrations of arsenic in toenails (1.25 μg g-1) and hair (0.437 μg g-1) exhibited the best correspondence with well water samples containing > 60 μg L-1 of arsenic. The prediction errors (false-positives and false-negatives) were 7.0 % and 6.6 % for toenails and hair, respectively. These MHP results reflected the most non-random outcome at each well water arsenic concentration threshold, and thus identified the greatest cause-and-effect relationship amongst these variables whilst minimizing classification errors.

abstract: Chemistry


title: Growth rates versus immunocompetence in nestling Leach's storm-petrels (Oceanodroma leucorhoa)

contributor:
Mills, Emily S. (author)
(Shutler, Dave) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2011

abstract: Life-history theory predicts trade-offs among life-history components. One potential  trade-off that I tested for is between growth rate versus immunity in nestling Leach’s  storm-petrels, Oceanodroma leucorhoa. The study was done on Bon Portage Island,  Nova Scotia. To test immune system strength (immunocompetence), two tests were  done: the phytohaemagglutinin skin-test (PHA test), and a bacteria-killing assay. The  PHA test assesses adaptive immune responses that involve antibodies tagging invaders  for destruction; adaptive immunity can maintain memory of invaders in future infections.  The bacteria-killing assay assesses innate immunity that can attack invaders in the blood,  primarily through phagocytosis. Growth rates of nestlings were measured by taking four  different morphological measurements on a regular basis. There was no significant  correlation found between growth rate of tarsus, bill, wing, or mass versus PHA swelling.  Likewise there was no significant correlation found between growth rate of tarsus, bill,  wing, or mass versus bacteria-killing ability. None of these results was statistically  significant (lowest P = 0.11). Thus my results suggest that there is no trade-off between  immunocompetence and growth rates in nestling Leach’s storm-petrels. I did find a  significant correlation between PHA swelling and mass on day of test, but this  relationship was not found for the bacteria-killing assay. Because my study was  observational, future work could manipulate nestling nutrition to affect growth rates, and  again test for trade-offs with immunocompetence.

abstract: Biology


title: Sedimentology and authigenesis of the lower Devonian Torbrook Formation ironstone, Torbrook, Nova Scotia, Canada

contributor:
Marshall, Luke A. (author)
(Pufahl, Peir K.) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2011

abstract: Ironstone in the lower Devonian Torbrook Formation of Nova Scotia accumulated in an array of storm-dominated, middle and distal shelf environments. Lithofacies stacking patterns indicate deposition occurred through the development of seven parasequences. Paraseqeunces range in thickness from 40 to 250 m thick and become progressively thicker through the Torbrook Formation. Individual parasequences coarsen from parallel laminated mudstones and ripple cross-laminated sandstones to iron cemented hummocky cross-stratified sandstones that are capped by marine flooding surfaces. Ironstone firmgrounds that mark flooding surfaces contain in situ and transported brachiopods and crinoids, suggesting mesotrophic nutrient levels predominated across the shelf.  Ironstone development is interpreted to have been restricted to flooding surfaces because low or net negative rates of sedimentation stabilized the iron redox interface within the sediment, which allowed pore waters to become saturated with iron. Saturation and precipitation of iron minerals across this redox interface is interpreted to have occurred through iron redox pumping. Iron redox pumping is a cyclic mechanism that concentrates iron in pore water through the dissolution of iron (oxyhydr)oxide below the iron redox interface. Precipitation occurs when ferrous iron diffuses upward through the sediment to combine with oxygen in suboxic pore water. This process links the cycling of iron to phosphorus and is likely responsible for the high levels of bioavailable phosphorus necessary to sustain firmground populations of brachiopods and crinoids. Important authigenic phases in these ironstone firmgrounds include hematite, chamosite, brethierine, and francolite

abstract: Earth & Environmental Sciences


title: Perceived teaching practices of physical education teachers and the exercise related thoughts and behaviours of their students

contributor:
Renshaw, Jessica (author)
(Shields, Chris) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2011

abstract: It has been reported that only 21% of Canadian youth are active enough for optimal health benefits and over 64% of females aged 12-19 years old are insufficiently physically active. It has been shown that the quality of instruction offered in Canadian physical education class may be a determining factor in the nature of the experience students receive and as a result this impacts their learning, skill acquisition and overall experience. Recent evidence highlights the importance of transformational leadership behaviours by both in the fields of business and physical education. However, little is understood as to how these behaviours may impact the thoughts and behaviours of those being taught or led. Based on Social Cognitive Theory, proxy-efficacy, RISE beliefs and self-efficacy may all be impacted by transformational teaching practices. As there is no published literature examining these constructs in concert within a physical education context, the present study aims to answer the question - Is there a relationship between the perceived teaching practices of physical education teachers and the self- and relational efficacy perceptions and exercise behaviours of their students?

abstract: Kinesiology


title: The design and development of the iAcadia iOS application

contributor:
Wooden, Ryan Glenn (author)
(Benoit, Darcy) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2011

abstract: The goal of the iAcadia project was to produce a high-quality mobile application  that could then be distributed to the public. The application brings together infor-  mation about Acadia and presents it in a format more suited to mobile devices. The  project was developed for Apple iOS devices and is written as a native application  rather than as a webpage. The project was inspired by similar applications available  for other institutions but is one of a very small group of similar applications designed  from scratch by students.  The client provides a clean, consistent interface to the user and uses elements that  are familiar to users of iOS devices, such as the main launcher view, which mimics the  Home screen of the device. The client brings together information from many di erent  online sources and creates an interconnected interface that allows users to access  information about many di erent parts of the university. It has news, videos, sports  scores and upcoming games, course listings, sta  information, Safety and Security  information, and an interactive campus map.  The client application receives the information from a server. That server brings  together the data from all the di erent sources and provides a simple, uni ed interface  to all the data. The server is responsible for getting new content from many di erent  sources and creating links between the di erent sections.  The application has been well received by users and has been downloaded from  the App Store over 2000 times in over 50 countries. Usage of the application is tracked  on the server, which shows that it is actively used by many people every day.

abstract: Computer Science


title: Corruption on an island paradise: An autoethnographic account of the Balinese police force

contributor:
Trask, Michael W. (author)
(Thomson, Tony) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2011

abstract: The nature of official corruption in Indonesia is viewed by many as being systemic. It is also a topic that remains in the minds of the country‟s population since the fall of the Soeharto regime. The rallying cry demanding the end to „Corruption, Collusion and Nepotism‟ was echoed throughout the country at the advent of the Asian Financial Crisis of 1997. The population had had enough of the immoral and incessant acts committed by those in power. Witnessing the action of corruption first hand, I use the method of autoethnography to explore my own experience and feelings at the time of the incident, gaining insight into the deviant nature of corruption.  By using a historical and theoretical framework and the method of autoethnography to explore the history of corruption, I argue that the actions of those in power that seem corrupt through our frame of reference are actually actions that are customs and can be seen as normal in their cultural context. While our own legal rational method of authority is at odds with the traditional method of patrimonial authority, the implementation of our rule of law is being inserted into Indonesian society. This move towards a more democratic rule of law conflicts with the power structure that has procured large profits, making it difficult to make way for change.

abstract: Sociology


title: In their own image: The evidence for the integration of freedwomen into Roman society, during the first century BCE and first century CE

contributor:
Shambrook, Brianna (author)
(Hewitt, Sonia) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2011

abstract: As former slaves, freedwomen were severely undervalued in Rome’s  freeborn society. The literary sources derived from Rome’s elite class have  created a negative stereotype that undermines the values and efforts of freedmen  and freedwomen. This thesis shows how freedwomen were able to create a  positive identity in Rome’s class-conscious society, despite elitist attitudes.  Through the analysis of recent scholarship on the lower classes and ancient  sources, such as epitaphs and funerary art, this study demonstrates how  freedwomen successfully established themselves after servility. The results of  this study show that by supplying the freedwomen perspective, missing  throughout these sources, we are able to reconsider the social history of Rome’s  lower class.

abstract: History & Classics


title: Petrography and geochemistry of drill core from the Taylors Brook property in the Stirling belt, southeastern Cape Breton Island, Nova Scotia

contributor:
Reid, Michael G. (author)
(Barr, Sandra) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2014

abstract: The Stirling belt in southeastern Cape Breton Island, Nova Scotia, is one of several belts of Precambrian rocks in the Avalonian Mira terrane of the northern Appalachian orogen. It consists of ca. 680 Ma volcaniclastic rocks, flows, porphyries, breccias, and clastic sedimentary rocks (Stirling Group), intruded by ca. 620 Ma dioritic to granitic plutons and overlain by Cambrian sedimentary rocks. It is in faulted contact at the L’Archeveque Fault with younger rocks of the Fourchu Group of the Coastal belt and the Devonian Lower St. Esprit Pluton. Based on the previously mined deposit at Stirling as well as numerous other sulphide occurrences, the Stirling belt has high potential for economic sulphide mineralization but outcrop is limited and hence the geology and tectonic setting are not well understood. This study of the petrography and geochemistry of drill core from the Taylors Brook area contributes to a better understanding of the rock units, geochemistry, mineralization, and tectonic setting of the Stirling belt. The rocks of the Taylors Brook area include basalt, quartz-feldspar porphyry, rhyolite, varied mafic and felsic tuff, cherty ash tuff, pyritic siltstone, mafic and porphyritic mafic dykes, younger quartz arenite, and the Lower St. Esprit Granite. The L’Archeveque Fault occurs at the contact between the rocks of the Stirling Group and the Lower St. Esprit Granite and separates the Stirling and Coastal belts. The volcanic rocks in the Taylors Brook area are calc-alkalic and formed in a volcanic-arc tectonic setting and the sedimentary rocks were deposited in an intra-arc basin. The mineralization that occurs in the Taylors Brook area is predominantly pyrite with minor chalcopyrite and sphalerite and forms semi-massive sulphide lenses at the contacts of quartz-feldspar porphyry units, as well as disseminated sulphides in siltstone.

abstract: Earth & Environmental Sciences


title: Digital in-line holography and the numerical reconstruction of holograms

contributor:
Bowman, Wesley A. (author)
(Robertson, Michael) (Thesis advisor)
(Williams, Peter) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2014

abstract: A hologram is the recorded interference pattern between a reference wave and a  scattered wave from an object. Although, the recording medium only captures the  intensity of the light from these waves, the information about both the amplitude and  the phase is still present in this recording, due to the interference fringes produced by  the superposition of these two waves. This information can be reconstructed numeri-cally  using the Fresnel-Kirchoff integral, which can be transformed into a numerically  efficient calculation using the convolution theorem.  The setup used in this thesis was in-line holography. In Digital In-line Holographic  Microscopy (DIHM), all of the components are aligned in a linear setup, and both the  reference and scattered waves are recorded on the same detector. The setup used in  this thesis contained a laser, two objective lenses, the object holder, a neutral density  (ND) filter, and a charged coupled device (CCD). The CCD allowed for direct digital  recording of the holograms.  Once the holograms were obtained from the DIHM, an open-source Python library,  HoloPy, was used to reconstruct the holographic images. Images from both Harvard  and Acadia Universities were recorded and reconstructed, which demonstrated the  successful acquisition of holograms and the reconstruction method. The DIHM that  was constructed at Acadia achieved a resolution of approximately 2.7 μm.

abstract: Physics


title: Crisis averted: neoliberalism's continued hegemony post-2008 and its implications for poverty and inequality discourse in Canada

contributor:
Costain, Emma (author)
(Stewart, Ian) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2014

abstract: With the upsurge in use of terms such as ‘income inequality’ and ‘the one percent’  following the 2008 financial crisis and protests including the Occupy Movement, many  theorists are – unconvincingly – confident that economic disparity in Canada and  elsewhere will soon be addressed through significant policy reform. The events of 2008  may have been termed ‘financial crisis’ but they are far from the crisis of legitimacy  required for an overthrow of neoliberal hegemony. Rather than having inspired radical  change, the aftermath of the financial crisis suggests a solidification of neoliberal  dominance. While the optimist views every crisis as an opportunity, the moment for  revolution may already be lost. Indeed, the case study of state and non-state discourse  presented in this thesis demonstrates that while discussion of poverty and income  inequality has increased in certain segments of Canadian society, the state remains  relatively unaffected by these halfhearted calls for egalitarianism. Furthermore, civil  society’s discourse of change is flawed, rooted in a populist, apolitical rhetoric of the  ‘middle class’ and ‘the 99 percent’ that fails to provide a sophisticated analysis of poverty  or class differences. This pacifying terminology inhibits the development of class-consciousness,  a necessary precondition of neoliberalism’s demise.  In this thesis, state discourse regarding poverty and inequality is investigated  through an examination of the Canadian federal budgets between 2008 and 2013. Non-state  discourse is studied through parliamentary debates, news articles from five  prominent sources – The Toronto Star, The Globe and Mail, The National Post, CBC  News, and CTV News – and the Canadian Centre for Policy Alternatives’ (CCPA’s)  annual Alternative Federal Budgets (AFBs). This study is guided by three primary  research questions: 1) What themes or trends emerged in state and non-state discourse  regarding income inequality and poverty reduction in Canada after the 2008 financial  crisis? 2) Is there a disconnection between state and non-state discourse regarding such  issues in Canada? 3) If differences are found between state and non-state discourse, what  accounts for these differences?  The findings of this case study suggest that the federal budgets display few, if any,  signs of change in discourse following the 2008 financial crisis. However, the  parliamentary debates reveal a different story – the financial crisis and subsequent  protests do appear to have had an impact on this non-state discourse. Perhaps most  prominent is an apparent increase in use of the term ‘income inequality.’ Surprisingly,  however, the analysis of the media’s reactions revealed minimal references to these social  movements. Finally, as expected, the AFBs featured numerous discussions of poverty and  income inequality in Canada, with a particular focus on the Occupy and Idle No More  Movements. The 2008 financial crisis may have altered the discourse surrounding poverty  and inequality within Canadian civil society, the media, and left-wing think tanks, but  until it reaches the state and policy reform is implemented, we have little to show for our  actions. Enacting meaningful political change necessitates a transformation of our  identities and requires sustained forms of collective action. Until then, the likelihood that  the status quo will continue to be upheld reflects the same misguided ratios made  (in)famous by the Occupy Movement: 99 to 1.

abstract: Politics


title: Paleoenvironments of the Devonian-Carboniferous Blue Beach Member of the Horton Bluff Formation, Nova Scotia, Canada

contributor:
Plante, Melanie (author)
(Pufahl, Peir K.) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2014

abstract: The Blue Beach Member of the Horton Bluff formation is one of the few fossil  sites in the world that contains tetrapod tracks of Tournaisian age. Body fossils and  trackways are preserved in a variety of shallow-water lithofacies that provide insight into  Romer’s Gap; a discontinuity between the late Devonian fishes and more evolved early  Carboniferous amphibians. Detailed sedimentologic description and sampling of a  recently acquired drill core of the Blue Beach Member yielded important information  regarding the environments these tetrapods colonized. The presence of flaser bedding as  well as authigenic glauconite and framboidal pyrite in wavy-laminated mudstone  indicates shallow coastal sediments accumulated in brackish or marine environments.  The preponderance of tetrapod trackways in supratidal deposits indicate that large  amphibians only existed in swampy backshore areas that were saturated with freshwater.  The recognition of marine facies in the Blue Beach Member reconciles the longstanding  question of whether tetrapods colonized a lacustrine, brackish or coastal marine setting.  These findings further illuminate the paleoenvironments of early tetrapods and support  the notion that these amphibians were not solely limited to freshwater lacustrine systems.

abstract: Earth & Environmental Sciences


title: The relationship between dietary and supplement practices and measured performance improvements among university level athletes

contributor:
Ferguson, Jared N. (author)
(Fowles, Jonathon) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2014

abstract: The maintenance and development of skeletal muscle mass plays an essential role in the management of many chronic medical conditions and improvement of athletic performance. Resistance training combined with nutritional strategies has been studied extensively in regards to the impact they have on muscle growth and repair. Specifically, the combination of resistance training (i.e. weight training) and the ingestion of workout supplements (i.e. essential amino acids and carbohydrates immediately following exercise) has been proven to significantly improve this muscle protein growth response. The Dietary Reference Intake for protein is listed at 0.8g/kg; however, protein recommendations of 0.8g/kg mainly apply to sedentary populations. Athletes looking to gain lean muscle mass are encouraged to consume between 1.2-1.7g/kg of protein daily. In relation to these recommendations, dietary practices around daily protein consumption are important to understand in athletic populations. In addition to protein supplementation with essential amino acids, other performance enhancing (ergogenic) nutritional aids such as creatine, glutamine, nitric oxide, and other supplements, have been linked to improved athletic performance in varying degrees. Many supplements have only recently been introduced to the market (over the last 20 years), and more continue to be released on a monthly basis. Research pertaining to the effectiveness of ergogenic aids is therefore not conclusive. Additionally, little research has been on comparing the extent of supplement use among male and female athletes. This study investigated the nutritional practices and supplement use in male and female varsity athletes at Acadia University. Results showed that male and female varsity athletes likely meet recommended intakes of protein, and most athletes follow post-workout nutrition guidelines; however, a low percentage of varsity athletes met healthy intakes of fruit and vegetables or water intake. There may be some relationship between dietary practices and changes in fat-free mass or changes in performance.

abstract: Kinesiology


title: A review and analysis of SpriteGen and its applications

contributor:
Reid, Kyle D. (author)
(Benoit, Darcy) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2013

abstract: The main objective of this project is to create a practical, accessible program which performs the efficient creation and maintenance of web sprites. Sub-objectives include completing this task with the highest possible efficiency, building an intuitive and usable interface for the program, and guiding users through the sprite generation process. Our goal is to provide a better option for the way sprites are built and maintained, so that it is easier to use them than to not.  The implementation uses C# and the Microsoft .NET 4.0 Framework to build an image-handling core and applications by which to access it. These include a command line program, a desktop interface and, eventually, a web portal. These programs will allow users to access our sprite generation core with whichever method they prefer, and will give them the flexibility required to build and automate program executions without hassle.  We conclude with a successful, working program which accomplishes many of the objectives we began with. This program uses many different algorithms and several advanced tools to complete this job, and remains as flexible and efficient as was outlined in the project specification.

abstract: Computer Science


title: The political and ecological origins of piracy along the Somali coast

contributor:
Bunten-Walberg, Amanda (author)
(Biro, Andrew) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2013

abstract: This thesis explores the political and ecological origins of Somali piracy.  Incidents of piracy along the coast of Somalia have increased rapidly in recent years, with  record highs in 2009 as 406 incidents of Somali piracy, more than half of the total  worldwide incidents of piracy that year, were reported. Nations around the world are  struggling to quell piracy in Somalia, however, the problem of piracy along the Somali  coast remains. In order to develop a deeper understanding of the phenomenon of Somali  piracy, this thesis will explore its root causes through primary and secondary source  research, focusing on the nuanced ways in which nature and humanity remake each other,  shaping piracy. This thesis will argue that Somali piracy is the product of a plurality of  multi-scale human-environment interactions that have continuously redesigned each  other, with the collapse of the Somali state, the perpetration of environmental injustices,  and the occurrence of natural disasters being key factors that shaped the development and  evolution of piracy in Somalia. This thesis enhances an understanding of the root causes  of Somali piracy, and lays the groundwork for a solution to piracy’s underlying  conditions to be crafted and implemented.

abstract: Environmental & Sustainability Studies


title: Numerical evaluation of the taxonomy of Geum radiatum and preliminary studies of the pollination biology of its Nova Scotian population

contributor:
Zinck, Marian C. (author)
(Vander Kloet, Sam) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 1996

abstract: Geum peckii Pursh and G. radiatum Michx. are two closely related  perennial herbs of the section Acomastylis (Roscaceae: Geum). Both are endemic  species, limited to the Appalachian Mountains, and for the former taxon, an  outlying population on Brier Island, Nova Scotia. Historically G. peckii had been  considered a variety of G. radiatum (sensu Gray, 1856, 1899), while Pursh  described it as a species in 1814. Using the current treatment of the taxa, there are only two known localities for Geum peckii: Mount Washington, New Hampshire  and Brier Island, Nova Scotia. Geum radiatum has been reported only from the  Roan Mountains, North Carolina.  There is wide current interest in plant population studies and their  relevance to conservation efforts. In acquiring information on the life history of  the species, assessments can be made as to how present management of a plant's  habitat may influence the survival of its populations. The study of a plant  population's reproductive biology indicates its sustainability, which could have  further implications in habitat management, particularly those species with few  populations.  By using numerical taxonomy (clustering techniques), this study found no  differences in floral nor vegetative characters to group 31 G. peckii and G.  radiatum specimens into two species. Therefore the older name Geum radiatum  Michx. is retained.  The pollination study of Brier Island plants showed that the plants are  pollinated by small flies. Nectar is produced sporadically. The flowers are  protogynous and herkogamous, which serve as barriers to self-pollination,  promoting cross-pollination. Experimental outcrossing produced a greater number  of achenes (51-62; p=.04) than selfing (19-52; p=.04). That selfed plants  produced some achenes indicated that the floral mechanisms provide only partial  barriers to self-pollination.

abstract: Biology


title: Examining impulsivity among individuals with sexual crimes against children

contributor:
Mooney, Kayla M. (author)
(Price, E. Lisa) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2014

abstract: Individuals who commit sexual crimes against children are a part of a widely  heterogeneous population. At present, little is known about how impulsivity manifests  itself within different populations who commit sexual crimes against children. The  purpose of the present study was to examine impulsivity across three groups with sexual  crimes against children: child pornography offenders, contact offenders with diagnoses of  pedophilic disorder, and contact offenders without diagnoses of pedophilic disorder.  Facet 3 scores from the Psychopathy Checklist-revised were used to measure impulsivity  in a sample of 616 adult male Nova Scotia residents drawn from the Nova Scotia  Forensic Sexual Behaviour Program database. Initial analyses confirmed prior findings  that child pornography offenders contained a greater proportion of individuals with  diagnoses of pedophilic disorder. Results also indicated that the population of contact  offenders was more impulsive than the group of child pornography offenders. More  specifically, contact offenders with pedophilic disorder were more impulsive than child  pornography offenders, but less impulsive than contact offenders without pedophilic  disorder, who demonstrated the highest impulsivity scores. The results mostly supported  the hypotheses. While impulsivity is a complex, multi-faceted construct, results of the  present study suggest that higher levels of behavioural impulsivity might be implicated in  certain forms of sexual offending against children. Results have significant implications  for assessment and treatment, specifically for the purpose of reducing recidivism.

abstract: Psychology


title: Biopolitical theory and the problem of ontology

contributor:
Kaulback, Nathan (author)
(Whitehall, Geoffrey) (Thesis advisor)
Acadia University (Degree grantor)

subject: LE3 .A278 2014

abstract: With the explosion of biopolitical analysis in political theory, this paper revisits the core  theoretical texts that are widely cited as the origin of the academic movement. The thesis  begins with the concept of the problem of ontology that has been developed in recent decades  and argues that while the key influences of this academic movement (Michel Foucault and  Giorgio Agamben) may appear to have similar positions on the topic, they are rather radically  divergent. While both authors focus on the impossibility of ontological concepts, Foucault  denies a logic, mechanism, or metaontology between this position and the necessity of  ontological conceptions, while Agamben explicitly articulates such a logic. Both authors share  another similarity however, insofar as each is concerned with the question of methodology  which goes beyond the simple identification of a problematic contemporary phenomenon such  as biopolitics. The implication of these findings is that a return to these texts is useful for  drawing our attention to our own methodological and ontological conceptions in regards to the  (undoubtedly different) situation we find ourselves in today.

abstract: Politics