Vortex generator jets (VGJs) have proven to be effective in minimizing the separation losses on low-pressure turbine blades at low Reynolds numbers. Experimental data collected using phase-locked particle image velocimetry and substantiated with a hot-film anemometer were used to answer fundamental questions about the influence of VGJs on a separated boundary layer. The data were collected on the suction surface of the Pack B blade profile, which has a non-reattaching separation bubble beginning at 68% axial chord. Two VGJ pulse histories were created with different frequencies, jet durations, and duty cycles. The mechanisms responsible for boundary layer separation control were shown to be a combination of boundary layer transition and streamwise vortical structures. Jet duration and relaxation time were important VGJ characteristics in determining the extent of control. The unsteady environment characterisitic of the low-pressure turbine section in a gas turbine engine effectively reduces the time-averaged separation zone by as much as 35%. Upstream blade rows create unsteady flow disturbances (wakes) that transition the flow. This transitioned flow propagates downstream, re-attaching the separation bubbles on the subsequent blade row. Phase-locked PIV and hot-film measurements were used to document the characteristics of this separation zone when subjected to synchronized unsteady wakes and VGJs. The phase difference between VGJ actuation and the wake passing, blowing ratio, and VGJ duration were optimized to achieve the greatest time-averaged control of the separation zone. The experimental data were used to identify the important characteristics of the wake/jet interaction. Phase-locked PIV measurements were taken to isolate the wake event (wake only), the VGJ event (jets only), and the synchronized combination of unsteady wakes and jets. The synchronized conditions achieved maximum separation bubble control. The presence of wake and jet induced calmed zones are also noted.

Creating a conducive environment for healthy eating can be achieved by empowering consumers with the necessary information to make informed nutritional choices. As a result, nutritional labeling has become increasingly imperative in assisting individuals in their daily purchasing decisions. Although research suggests that front-of-pack labeling is an effective means of informing consumers about healthier food options, no single labeling system has proven successful in this regard. The absence of a definitive labeling system ideal for all purposes makes it challenging to determine the most effective one. This uncertainty has led to a gap in the literature, which provided an opportunity for further research to examine the various labels and related concepts and factors. This dissertation aimed to fill the gap in the literature by studying two popular front-of-pack labeling systems: The Health Star Rating system and Nutri-Score. Four research chapters have been included to achieve this objective. The study commenced with a systematic review of the Health Star Rating label in the literature. The next chapters examined the impact of front-of-pack nutrition labels on consumers' food choices and preferences. The research investigated how the presence or absence of a label influences consumer decision-making and how individual differences play a role in interacting with these nutrition labels. Finally, the performance of the nutrition labels is examined in the context of existing beliefs and attitudes. This last study provided a fresh perspective on the effect of Nutri-Score on food choices by exploring its impact on consumers’ prior beliefs, intuitive thinking, analytical processing, and judgment of healthiness. In conclusion, the body of literature reviewed and the experimental data gathered in this thesis suggest that food labels are effective at influencing consumer choice; however, due to this, special caution must be exercised due to the risk that they could be used more as a marketing tool than as a genuine aid to informed choice.

<p>The introduction of metal supported cells may be a key innovation in the development of solid oxide fuel cell (SOFC) technology. The objective of this study was to develop a process of co-firing the ceramic layers of a solid oxide fuel cell attached to their porous metal support. This is a major departure from the traditional fuel cell architecture where the support layer is a ceramic composite made of YSZ and NiO.</p> <p>The problems to be eliminated during the fabrication process include the warping, cracking and delamination of the cell during the co-sintering process.</p> <p>In this study, the porous metal layer was produced by the freeze tape casting process. During co-sintering, it is necessary to match the relative shrinkage between the metal and ceramic layers. Different parameters which can influence the relative shrinkage were explored, including the heating rate, sintering temperature, sintering time, cell thickness, solid loading of the green tapes, applications of wet and dry hydrogen in the sintering atmosphere, as well as a change of the electrolyte material. Specifically, GDC was tested as an alternative electrolyte to YSZ.</p> <p>Since the porous metal substrate is exposed to air during fuel cell operation, it must be protected from oxidation. Therefore, the pack cementation method was used to apply a layer of aluminum onto the metal substrate. Variables such as temperature and exposure time of the coating materials were investigated in this thesis.</p> / Master of Applied Science (MASc)

The electric vehicle market has rapidly expanded due to technological advancements for the last decade and a key enabler is the development of high-performance batteries with greater energy density, faster charging, and longer lifespan. The construction equipment sector faces unique challenges in electrification, including high power demands, extended operating hours, and the need for minimal downtime. To address these challenges Volvo Construction Equipment is investigating a battery swap system solution that allows for quick battery swaps, reducing downtime and a decoupled lifetime from the machines. The aim for this study is to design a battery pack used for the battery swap system while answering the following research questions: RQ1: What configuration of battery modules, rack and auxiliary systems achieve the highest energy density when designing a battery pack for construction equipment? RQ2: What factors should be considered when designing the battery modules, rack, and auxiliary systems to achieve the highest energy density of a battery pack for construction equipment? This project followed a limited version of Ulrich et al.'s (2019) product development process, focusing on concept development and system-level design for a battery swapping system. An inductive research approach was taken, gathering qualitative and quantitative data from interviews, literature, documents, and meetings to create a holistic understanding of the project challenges. A structured literature review was conducted using relevant keywords across multiple databases, employing techniques like forward and backward snowballing. Data analysis methods, including conversation analysis, were employed to structure and analyze collected data, ensuring validity and reliability through triangulation, and cross-referencing with experts at Volvo. Empirical studies were conducted through benchmarking and a case study, providing quantitative data on specifications and qualitative insights from internal documentation and communication with product developers. The findings formed an iterative concept generation process, emphasizing the importance of exploring diverse possibilities in the early stages. The design process involved evaluating previous battery pack solutions, working within predefined constraints like using a specific shell, internally developed battery modules, auxiliary components while satisfying a set of stakeholder needs. Some auxiliary components and a rack that supports the battery modules were also developed as there is a new internal layout of the battery pack. This resulted in a conceptual battery pack that theoretically have a 30% higher energy density than the previous battery pack solutions. The proposed solution enables Volvo Construction Equipment to offer machines with longer runtimes and increased productivity by maximizing the energy storage capacity within the given constraints.

Aluminium smelting is a high temperature electrometallurgical process, which suffers considerable inefficiencies in power utilization and equipment maintenance. Aluminium smelting cell works in the extreme environments that contain extraordinarily aggressive gases, such as HF, CO and SO2. Mild steel used as a structural material in the aluminium industry, can be catastrophically corroded or oxidized in these conditions. This project was mainly concerned with extending the lifetime of metal structures installed immediately above the aluminium smelting cells. An aluminium-rich coating was developed on low carbon steel A06 using pack cementation technique. Yttria (Y2O3) was also used to improve the corrosion resistance of coating. Kinetics of the coating formation were studied. XRD, FESEM and FIB were employed to investigate the phase constitution and the surface morphology. Together with other potentially competitive materials, aluminium-rich coating was evaluated in simulated plant environments. Results from the long time (up to 2500h) isothermal oxidation of materials at high temperature (800??C) in air showed that the oxidation resistance of coated A06 is close to that of stainless steel 304 and even better than SS304 in cyclic oxidation tests. Coated A06 was also found to have the best sulfidation resistance among the materials tested in the gas mixture contains SO2 at 800??C. Related kinetics and mechanisms were also studied. The superior corrosion resistance of the coated A06 is attributed to the slow growing alpha-Al2O3 formed. Low temperature corrosion tests were undertaken in the gas mixtures containing air, H2O, HCl and SO2 at 400??C. Together with SS304 and 253MA, coated A06 showed excellent corrosion resistance in all the conditions. The ranking of the top three materials for corrosion resistance is: 253MA, coated A06 and SS304. It is believed that aluminised A06 is an ideal and economical replacement material in the severe corrosive aluminium smelting cell environment.

The overall purpose of this study was to define the water balance of feedlot pens in a Saskatchewan cattle feeding operation for a one year period. Although the initial intention of the study was focused upon an active feedlot, cattle were removed from the pens in July 2003. Therefore, the year of analysis was conducted on the manured surface of an inactive feedlot. The water balance was also performed on a scraped soil surface, since manure is removed from the pens and spread on agricultural land, leaving the pen surfaces bare for a short period of time each year. <p>During the monitoring period (Sept. 2003 to Aug. 2004), 313 mm of precipitation was received at the feedlot, but only 84 mm of that total was received before June 2004. Winter precipitation was very low (33 mm) and there was no observed runoff from it. Runoff collection weirs in operation for only part of the summer recorded no runoff. The Green-Ampt and USDA SCS runoff models, as well as a snowmelt runoff equation, were used to predict runoff from both the manure pack, as well as the scraped soil surface. Using manure and soil hydraulic parameters determined in the laboratory (from falling head permeameter measurements) and the field (from rainfall simulations), as well as incorporating the greatest 24 hour rainfall amounts and 30 minute intensities experienced at the feedlot, the USDA model found that 29 mm of runoff would occur from the scraped soil surface. Additionally, snowmelt runoff was estimated to be 19 mm for the winter precipitation received. Drainage beneath the 0.6 m soil depth was negligible and the top 0.6 m of soil experienced an increase in moisture of 54 mm. Finally, 211 mm was lost as evaporation. For the manure pack, no runoff was predicted using the Green-Ampt and USDA SCS models and snowmelt runoff equation, which corresponded well to the lack of runoff measured both from the weir and rainfall simulations. Drainage beneath 0.6 m soil depth was negligible. Of the 313 mm of precipitation that fell during the study year, 42 mm was stored within the manure pack and the rest was lost as evaporation (271 mm).

The overall purpose of this study was to define the water balance of feedlot pens in a Saskatchewan cattle feeding operation for a one year period. Although the initial intention of the study was focused upon an active feedlot, cattle were removed from the pens in July 2003. Therefore, the year of analysis was conducted on the manured surface of an inactive feedlot. The water balance was also performed on a scraped soil surface, since manure is removed from the pens and spread on agricultural land, leaving the pen surfaces bare for a short period of time each year. <p>During the monitoring period (Sept. 2003 to Aug. 2004), 313 mm of precipitation was received at the feedlot, but only 84 mm of that total was received before June 2004. Winter precipitation was very low (33 mm) and there was no observed runoff from it. Runoff collection weirs in operation for only part of the summer recorded no runoff. The Green-Ampt and USDA SCS runoff models, as well as a snowmelt runoff equation, were used to predict runoff from both the manure pack, as well as the scraped soil surface. Using manure and soil hydraulic parameters determined in the laboratory (from falling head permeameter measurements) and the field (from rainfall simulations), as well as incorporating the greatest 24 hour rainfall amounts and 30 minute intensities experienced at the feedlot, the USDA model found that 29 mm of runoff would occur from the scraped soil surface. Additionally, snowmelt runoff was estimated to be 19 mm for the winter precipitation received. Drainage beneath the 0.6 m soil depth was negligible and the top 0.6 m of soil experienced an increase in moisture of 54 mm. Finally, 211 mm was lost as evaporation. For the manure pack, no runoff was predicted using the Green-Ampt and USDA SCS models and snowmelt runoff equation, which corresponded well to the lack of runoff measured both from the weir and rainfall simulations. Drainage beneath 0.6 m soil depth was negligible. Of the 313 mm of precipitation that fell during the study year, 42 mm was stored within the manure pack and the rest was lost as evaporation (271 mm).

Au cours de ce travail, des revêtements intermétalliques TiAlx (x=1,2,3) ont été élaborés sur des substrats à base titane : le titane pur et l'alliage commercial, TA6V. L'objectif était de réaliser des revêtements d'aluminiure en surface et d'étudier le comportement des matériaux revêtus vis-à-vis de l'oxydation à haute température sous air, sous air enrichi en vapeur d'eau et en présence de soufre. Les matériaux revêtus ont été testés à trois températures : 700°C, 800°C et 900°C. Les revêtements ont été réalisés à 1000°C par la méthode de cémentation en caisse. Les revêtements réalisés par ce procédé sont toujours adhérents au substrat. Pendant la réaction d'oxydation, l'existence d'un processus de rétrodiffusion de l'aluminium modifie la nature des phases et l'organisation du revêtement. Les phases TiAl et TiAl2 ne sont pas suffisamment riches en aluminium pour promouvoir la formation d'une couche d'alumine protectrice quelle que soit la température d'oxydation. Lorsque ce sont ces phases qui sont à la surface du revêtement, on assiste toujours à la formation d'une couche superficielle de rutile TiO2. Quand elle constitue la sous-couche externe du revêtement, la phase TiAl3 est assez riche en aluminium pour former une couche d'alumine -Al2O3 couvrante, compacte et protectrice.

Aluminium smelting is a high temperature electrometallurgical process, which suffers considerable inefficiencies in power utilization and equipment maintenance. Aluminium smelting cell works in the extreme environments that contain extraordinarily aggressive gases, such as HF, CO and SO2. Mild steel used as a structural material in the aluminium industry, can be catastrophically corroded or oxidized in these conditions. This project was mainly concerned with extending the lifetime of metal structures installed immediately above the aluminium smelting cells. An aluminium-rich coating was developed on low carbon steel A06 using pack cementation technique. Yttria (Y2O3) was also used to improve the corrosion resistance of coating. Kinetics of the coating formation were studied. XRD, FESEM and FIB were employed to investigate the phase constitution and the surface morphology. Together with other potentially competitive materials, aluminium-rich coating was evaluated in simulated plant environments. Results from the long time (up to 2500h) isothermal oxidation of materials at high temperature (800??C) in air showed that the oxidation resistance of coated A06 is close to that of stainless steel 304 and even better than SS304 in cyclic oxidation tests. Coated A06 was also found to have the best sulfidation resistance among the materials tested in the gas mixture contains SO2 at 800??C. Related kinetics and mechanisms were also studied. The superior corrosion resistance of the coated A06 is attributed to the slow growing alpha-Al2O3 formed. Low temperature corrosion tests were undertaken in the gas mixtures containing air, H2O, HCl and SO2 at 400??C. Together with SS304 and 253MA, coated A06 showed excellent corrosion resistance in all the conditions. The ranking of the top three materials for corrosion resistance is: 253MA, coated A06 and SS304. It is believed that aluminised A06 is an ideal and economical replacement material in the severe corrosive aluminium smelting cell environment.

In connection to the increasing awareness of vehicles and its impact on the environment, the interest in the electric vehicle market has shown a significant growth in the recent years. According to forecasts, it is also projected to increase further in the future. These electric vehicles are driven by lithium-ion batteries with an expected service life of 5-15 years depending on different technology generations and design concepts. After the given service life, the battery has lost approximately 20 percent of its capacity and is no longer permitted to be used in its original application area again, out of safety reasons. Although the retired battery pack is not suitable for vehicles, its remaining capacity can still be utilized in other applications. Hence, the term second life has become a common subject in the automotive industry, where companies are trying to find new application areas for the retired electric vehicle battery packs. Common methods regarding second life of electric vehicle batteries are processes such as remanufacturing, repurposing and re-use. These presented second life methods are from a reverse logistics perspective. Second life alternatives enable a better sustainability and reduces the environmental impact by re-using and recycling existing materials.   In this thesis, the authors examined different second life concepts with the same prerequisite, an electric vehicle lithium-ion battery pack with an energy capacity of 20 kWh. The project has been conducted in a company that is one of the leading manufacturers in the heavy-duty industrial vehicle industry, which currently is developing their electric vehicle machines. Several different concepts have been generated and analysed to find the most applicable business model concepts from a second life perspective. The purpose has been to investigate and calculate which of these business model concepts are most feasible from an economic and a reverse logistics perspective. In order to fulfil the purpose, the following research questions have been formulated:   RQ1: Which secondary use business model concepts are feasible for battery packs of electrified machines? RQ2: Out of the above identified concepts, which business model concept is economically feasible and how can its reverse logistic be composed?   In order to answer the research questions, the authors have analysed different cost aspects and forecasts based on existing research and case company data. This is performed to develop the most profitable concepts based on the collected data, where the generated ideas concluded in three final concepts. For these concepts, individual business model canvases were created to illustrate all important parts of the concepts. The thesis resulted in an economic analysis of the three concepts, visualizing function diagrams and comparing them to each other, to identify the most applicable concept for the case company. The remanufacturing concept proved to be the most applicable one, where its associated reverse logistics and recycling process were investigated and determined. In conclusion the thesis can firstly contribute to future research by the created process map that companies can use and apply in their second life process, correlated to the managerial implications. Secondly, the remanufacturing concept can be a potential future investment for the case company, considering all valuable factors that have been analysed throughout the thesis.     Keywords: Battery pack, Battery secondary use, Business model, Reverse logistic, ESS, Remanufacturing, Battery repurposing, re-use, Battery second life economic analysis.