Le couplage de la réaction et de l’échange thermique au sein du même appareil est intéressant lors de la mise en oeuvre de synthèses exothermiques. L’appareil étudié est un échangeur/réacteur fonctionnant en continu dont la structure est basée sur celle des échangeurs de chaleur à plaques. Le passage du batch au continu n’est pas sans difficultés et une des manières d’intensifier les transferts tout en conservant un temps de séjour suffisant (régime laminaire) est de structurer, en 2D, le chemin réactionnel. Les caractérisations expérimentales et numériques de différentes géométries de canaux ondulés ont permis de comprendre les mécanismes qui influencent les performances thermohydrauliques et le comportement des écoulements. Des corrélations reliant les critères de performance au nombre de Dean ont été établies et la démarche d’optimisation d’une géométrie en fonction des contraintes d’utilisation a pu être définie. Les premiers pas vers l’extrapolation font l’objet de la dernière partie de ces travaux et présentent un enjeu important pour le développement industriel de ces technologies. Les résultats de cette étude ont souligné l’intérêt d’un paramètre adimensionnel caractéristique : le nombre de Dean interne, qui permet de conserver les performances thermo-hydrauliques et donc de prédire leur évolution lors du processus de changement de taille. / Coupling reaction and heat transfer in the same unit is an interesting way to perform exothermic reactions. The studied apparatus is a continuous heat exchanger/reactor. Its structure is based on plate heat exchangers’ one. The main difficulty when transposing batch reactions to continuous ones is to intensify the heat and mass transfers and maintain at the same time enough residence time (laminar regime). A way to remove this barrier is to structure in two dimensions the chemical path in order to obtain a wavy channel. The experimental and numerical characterizations of several wavy geometries allowed us to understand the mechanisms’ impact on the thermo-hydraulic performances and on the flow behaviour. The performances criteria have been correlated to the Dean number and the optimisation of the geometry has been made according to industrial specifications. Finally, the scale-up procedure has been studied. Our results showed that the conservation of a characteristic number: the internal Dean number allows the prediction of the performances and of the flow behaviour when the characteristic size of the wavy channel increases.

In the management of threatened and endangered species, informed population estimates are essential to gage whether or not recovery goals are being met. In the case of Pacific salmonids, this evaluation often involves sampling a small subset of the population and scaling up to estimate larger distinct populations segments. This is made complicated by the fact that fish populations are not evenly distributed along riverscapes but respond to physical and biological stream properties at varying spatial extents. We used rapid assessment survey methods and the River Styles classification to explore fish-habitat relationships at a continuous network scale. Semi-continuous surveys were conducted across nine streams in the upper Middle Fork John Day River watershed and increased the number of sites surveyed eight-fold over other monitoring methods within the watershed. Using this increased sample size and continuous habitat metrics we improved watershed-wide steelhead (Oncorhynchus mykiss) abundance models. We first validated the distinctions among River Styles through a classification analysis using physical metrics measured at the rapid assessment sites. Overall classification accuracy, using a combination of reach and landscape scale metrics, was 88.3% and suggested that River Style classification was identifying variations in physical morphology within the watershed that was quantifiable at the reach scale. Leveraging the continuous River Styles classification of physical habitat and a continuous model of primary production improved the prediction of steelhead abundance across the network. Using random forest regressions, a model that included only habitat metrics resulted in R2 = 0.34, while using the continuous variables improved the model accuracy greatly to R2 = 0.65. Random forest allowed for further investigation into the predictor variables through the analysis of the partial dependence plots and identified a gross primary production threshold, below which production might be limiting steelhead populations. This method also identified the rarest River Style surveyed within the watershed, Confined-Valley Step Cascade, as the morphology that had the largest marginal effect on steelhead. The inherent physical properties and boundary conditions unique to each River Style has the potential to inform fish-habitat relationships across riverscapes and improve abundance estimates on a continuous spatial scale.

The European battery market is in rapid growth and the industry actors are ramping up production as well as exploring international expansion opportunities. However, due to the relative novelty of the industry in Europe, there is a lack of benchmark companies and established frameworks for successful expansion. Existing studies in this field primarily focus on strategic solutions such as sourcing strategies and supplier relationship management, neglecting the utilization of supporting operative functions. Although some studies acknowledge the significance of these supporting functions, there is a lack of research providing models for their utilization. This research gap motivates the aim of this study to address this issue and contribute to the existing literature. The purpose of this study is to develop a comprehensive and adaptable expansion strategy that European battery manufacturers can employ when expanding their production facilities, while ensuring a high-quality procurement function. This was met by collecting qualitative data through interviews. The interviews were primarily with respondents from the case company, supplemented by inputs from relevant external participants. By conducting a case study focusedon the procurement department, valuable insights were gained, and the identified expansion strategy can serve as a valuable resource for industry practitioners. The main finding of this research is the battery manufacturers need for a structured expansion step model that outlines both the execution steps and their sequential order. The steps of the framework are: (1) Assure Management Support, (2) Create a Dedicated Expansion Team, (3) Adjust & Consolidate Systems, (4) Define Roles & Responsibilities, (5) Train & Incentives Employees, (6) Control Access Management, (7) Create & Maintain Master Data, and lastly, (8) Initial Supplier Contact. / Batterimarknaden i Europa växer snabbt. Företagen ökar sin produktion samtidigt som de undersöker möjligheter till att expandera internationellt. Vidare är marknaden i Europa relativt ny. Det innebär att det saknas större etablerade företag, riktlinjer och system att jämföra sig med om hur man expanderar på bästa sätt. Tidigare studier inom området har främst fokuserat på strategiska lösningar, såsom inköpsstrategier och hantering av leverantörer, men har förbisett utforskandet av hur man ska använda stödjande operativa funktioner. Även om vissa studier betonar vikten av dessa stödfunktioner är forskning som tillhandahåller modeller för användning av stödfunktioner bristfällig. Detta forskningsgap motiverar syftet med studien, vilken är att fokusera på modeller och bidra till den befintliga litteraturen. Målet med denna studie är att utveckla en omfattande och anpassningsbar expansionsstrategi som europeiska batteritillverkare kan använda vid expansion av sina produktionsanläggningar samtidigt som de säkerställer en högkvalitativ inköpsfunktion. För att uppnå detta har kvalitativa data samlats in genom intervjuer. Intervjuerna har främst genomförts med respondenter från det studerade företaget och har kompletterats med bidrag från relevanta externa deltagare. Genom att genomföra en fallstudie inom inköpsområdet har många värdefulla insikter erhållits, framför allt den identifierade expansionsstrategin som kan ses som en värdefull resurs för batteritillverkare. Det huvudsakliga resultatet av denna forskning är att batteritillverkarna har behov av en strukturerad stegmodell för expansion som tydligt anger både utförandestegen och deras sekventiella ordning. Stegen i ramverket är: (1) Säkra ledningens stöd, (2) Skapa en dedikerad expansionsgrupp, (3) Anpassa & konsolidera system, (4) Definiera roller & ansvar, (5) Utbilda & ge incitament till anställda, (6) Kontrollera åtkomst (7) Skapa & underhålla master data, och slutligen, (8) Initiera leverantörskontakt.

Background and Objectives: HIV in a major public health problem in many countries of the world. Recent advances in care for people living with HIV such as the use of antiretroviral medication have reduced the mortality and morbidity associated with HIV infection. However, many people receiving antiretroviral therapy do not take it as prescribed and still experience sub-optimal health outcomes. Mobile phone text messaging is emerging as an important tool in health care, and HIV in particular. Our objectives were to explore the determining factors for adherence to antiretroviral therapy, test text messaging as an adherence enhancement tool, develop a framework for community ownership of a text messaging program and describe strategies for transfer of evidence in HIV to other conditions. Methods: This research is primarily based in Yaoundé, Cameroon, and employs a variety of methodologies, including a systematic review, two cross- sectional surveys, a randomized controlled trial, an individual patient data meta-analysis, a mixed methods study and a systematic review of systematic reviews. Results and Conclusions: Two-way weekly text messaging is an effective strategy in improving adherence to antiretroviral therapy and enhancing provider-client communication. People living with HIV in Yaoundé, Cameroon like receiving text messages, and are willing to own and run a text messaging program. Text messaging interventions may be transferred to other conditions by integrating services or by copying what works in HIV. Further research on potential harms, cost effectiveness and text messaging for other chronic conditions is warranted. / Thesis / Doctor of Philosophy (PhD)

BACKGROUND: Evidence supports the importance of Early Childhood Development (ECD) interventions to improve children's health, lifelong productivity, and human capital. However, ECD programs are not scaled sufficiently to reach many of the 250 million young children globally who are not meeting their developmental potential. Practical guidance is limited on how to scale ECD programs effectively. This mixed-method study explored the contextual and implementation determinants of scaling up ECD programs in Zambia, using one large-scale, community-based parenting group program (Scaling Up Early Childhood Development in Zambia (SUpErCDZ) program) as a case study. The goal was to generate recommendations for policymakers and implementers in Zambia and other LMICs. METHODS: This study was guided by the WHO/ExpandNet scale-up framework and the Intervention Scalability Assessment Tool (ISAT). A total of 30 key informant interviews were conducted with program staff, government officials, academic partners, implementing partners of other ECD programs, and donors. Qualitative transcripts were analyzed using thematic analysis according to the framework method. A budget impact analysis (BIA) was conducted using prospectively collected program cost and implementation data supplemented by online sources and interviews with program staff. The total cost of scale-up over five years using three scenarios (low, medium, and high intensity) was modeled. RESULTS: According to government officials, donors, and partners, the most common contextual factors influencing scale-up ECD programs are political commitment, availability of an overarching or multisectoral ECD policy, availability of resources, and integration of ECD programs into existing government structures. In addition, multisectoral collaboration, stakeholders’ engagement, and sociocultural factors emerged as themes essential to scale-up. From the perspective of the program staff, the key facilitators of ECD implementation were stakeholders’ engagement, sociocultural factors (cultural norms and beliefs), adaptation of the intervention to the context, integration into existing government structures, and intervention characteristics. In addition, providing incentives to Community-Based Volunteers (CBVs) emerged as critical to sustainability. The main barriers to implementation identified by the program staff were the use of culturally inappropriate activities within the ECD curriculum, lack of incentives (financial or in-kind) to caregivers and CBVs, and unforeseen contextual circumstances (COVID-19 pandemic and insecurity). The budget impact analysis showed that the total cost and budget for scaling up SUpErCDZ or a similar ECD program depends on the magnitude of the scale-up in terms of geographic breadth and depth (coverage within specific geographic areas). Based on our scale-up scenarios, the estimated cost of scaling up this program over five years ranged between US$1.74M to US$4.3M depending on the breadth (how many provinces) and depth (how many health facilities, CBVs, and caregivers) of implementation. CONCLUSION: Multiple complex and interrelated contextual and implementation factors influence the scaling up of ECD programs in Zambia. To ensure equitable access to ECD programs for children under five in Zambia, policymakers and implementers will need to consider these when planning to scale up ECD interventions in Zambia. / 2025-08-04T00:00:00Z

Alors que la découverte de matériaux conducteurs de faible dimension fait progresser la mi- niaturisation des composants électroniques, les transistors à effet de champ (FET) peuvent désormais incorporer des éléments à molécule unique comme canal ou grille. Ces petites architectures permettent, entre autres, l’étude de molécules uniques, notamment par l’ob- servation de leur dynamique de repliement-dépliement ou de liaison. Ces études ont été principalement réalisées avec des transistors à effet de champ à base de matériaux unidimen- sionnels (1D) tels que les nanotubes de carbone (CNT) ou les nanofils de silicium. Du fait de leur dimensionnalité réduite, ces matériaux offrent un bon contrôle de leur interaction avec les molécules 0D, et donc de leur intégration au circuit. Cependant, ces matériaux 1D présentent des problèmes de reproductibilité et de mise à l’échelle, du fait qu’ils sont difficiles à croître et/ou à assembler dans les dispositifs FET. Cette thèse s’intéresse à l’utilisation d’un matériau carboné à deux dimensions, le gra- phène, comme alternative pour la fabrication de dispositifs pour l’étude de dynamiques de molécules uniques. En effet, le graphène est un matériau à deux dimensions composé d’un ré- seau hexagonal d’atomes de carbone, avec une excellente conductivité électrique ainsi qu’une chimie à base de carbone permettant l’ancrage de molécules biologiques à sa surface, ce qui en fait un candidat de choix pour la détection électrique de molécules individuelles. Sa di- mensionnalité est aussi compatible avec des procédés de microfabrication à grande échelle, ce qui offre la possibilité d’études statistiques sur de grands nombres de dispositifs. Ainsi, la détection de molécules biologiques utilisant des transistors à effet de champs à base de graphène (GFET) a connu un développement et un engouement important au cours de la dernière décennie, mais plusieurs aspects restent à résoudre, notamment la mise à l’échelle de la fabrication, le contrôle de la chimie de fonctionnalisation, et la miniaturisation du canal à l’échelle de la molécule unique. Dans cette thèse, des contributions sur ces trois aspects sont présentées. Premièrement, je décris une méthode de mise à l’échelle du transfert de graphène dans une optique d’indus- trialisation, par la conception et l’implémentation d’un montage de transfert de graphène permettant l’automatisation et l’augmentation du rendement de la fabrication de GFET. Je m’intéresse ensuite à la fonctionnalisation des dispositifs de graphène avec une molécule d’ancrage communément utilisée dans le cas des biodétecteurs basés sur des GFET, afin de révéler les cinétiques associées à l’adsorption et à l’accumulation de la molécule à la surface du graphène. Enfin le dernier chapitre décrit la conception d’une architecture de GFET pour l’accueil d’une molécule unique d’ADN, basée sur des nanoconstrictions mises en place dans le canal de graphène. Ces constrictions ont été obtenues à l’aide de la lithographie par faisceau d’électrons (EBL) et gravure ionique réactive profonde (DRIE), qui nous permet de modeler des structures à haute résolution de quelques dizaines de nanomètres dans le canal de graphène. Des nanopuits perpendiculaires à la constriction sont par la suite ouverts dans de la résine, favorisant le confinement de la chimie d’immobilisation de la molécule unique en un seul point. J’explore ensuite la liaison d’un brin unique d’ADN sur la nanoconstriction, et l’étude dynamique de son repliement. Cette thèse présente donc des résultats innovants en termes d’architectures et de procédés de mise à l’échelle de GFET à des fins de biodétection. / With the discovery of low-dimensional conductive materials advancing the miniaturization of electronic components, field-effect transistors (FET) can now incorporate single-molecule elements as a channel or gate. Among their applications, these small architectures allow single-molecule studies, for instance by observing their folding-unfolding or binding dy- namics. These studies were mainly carried out with field-effect transistors based on one- dimensional (1D) materials such as carbon nanotubes (CNT) or silicon nanowires (SiNW). Due to their reduced dimensionality, these materials offer good control on their interaction with 0D molecules, and therefore of their integration into the circuit. However, these 1D materials present reproducibility and scaling issues, due to the fact that they are difficult to grow and/or assemble in FET devices. This thesis focuses on the use of a two-dimensional carbon-based material, graphene, as an alternative for the fabrication of devices for studying the dynamics of single molecules. Graphene is a hexagonal network of carbon atoms that offers an excellent electrical conduc- tivity as well as a carbon-based chemistry for anchoring biological molecules on its surface, this makes it a prime candidate for the electrical detection of individual molecules. Above all, its dimensionality is compatible with large-scale microfabrication processes, which offer the possibility of statistical studies on a large number of devices. Thus, the detection of biological molecules using graphene-based field-effect transistors (GFET) has experienced significant development over the past decade, but several aspects remain to be resolved, including scale- up of the manufacturing, control of the functionalization chemistry, and miniaturization of the channel at the single molecule scale. In this thesis, I present contributions on these three aspects. First, I describe a method for scaling up graphene transfer in an industrialization perspective, by designing and implementing a graphene transfer setup allowing automation for increasing the yield of GFET fabrication. I then focus on the functionalization dynamics of graphene devices with an anchor molecule named PBASE (1-Pyrenebutyric acid N-hydroxysuccinimide ester) commonly used in the case of GFET-based biosensors, which reveals the adsorption and accumulation kinetics of the molecule on the graphene surface. Finally, I describe the design of a GFET architecture based on nanoconstrictions implemented in the graphene channel, designed to host a single molecule. These constrictions were obtained using electron beam lithography (EBL) and deep reactive ion etching (DRIE), which allows the modeling of high-resolution features of a few nanometers in the graphene channel. Nanowells were opened in the resin perpendicular to the constriction, promoting single-point, single-molecule chemistry. I then explore the immobilization of a single strand of DNA on nanoconstriction, and the dynamic study of its folding. This thesis therefore presents innovative results in terms of architectures and scaled implementation processes of GFET for biodetection purposes.

Lignocellulosic biomass is a promising alternative to non-renewable fossil fuel resources for the sustainable production of fuels and chemicals. Levulinic acid (LA) is considered to be a versatile platform chemical which can be derived from biomass and further upgraded to high-value products like levulinate esters. In this work, the direct chemical conversion of lignocellulosic biomass to ethyl levulinate (EL) through LA was studied in collaboration with Gascon Biomass Research Inc. in an effort to valorize their surplus of lignocellulosic feedstock obtained from biomass recycling activities. A novel one-pot, biphasic, acid-catalyzed hydrolysis-esterification process developed by Prof. Tom Baker's lab (uOttawa Chemistry) was used. Kinetic analyses of the overall reaction pathway and major reaction steps were performed to investigate the effect of reaction conditions such as time, temperature, alcohol concentration, and catalyst concentration and evaluate the kinetic and thermodynamic parameters. Reactions were well modeled by power law rate equations with applicability of the Arrhenius expression and exhibited nearly first-order dependence with respect to each of the corresponding reactants and catalyst, as expected. Kinetic studies of LA esterification to various levulinate esters showed that the reaction is endothermic, endergonic, non-spontaneous, and non-rate-limiting. Increased alcohol alkyl chain length and branching reduced the thermodynamic favourability of LA esterification, likely due to steric effects. Process considerations such as reactor pressure, LA and EL partitioning, solvent:feedstock ratio, solvent recycling, and alternative feedstocks were investigated through various lab-scale studies and simulation case studies with UniSim® Design. The results of experimental studies informed the development of a preliminary potential process flow diagram consisting of eleven batch slurry reactors under agitation in parallel. The product streams feed into a continuous separation process composed of flash vessels and distillation columns to separate and purify the various products, intermediates, unconsumed reactants, and recoverable catalyst and solvent. This work ultimately informs decisions regarding future pilot-scale experiments, process design, and optimization for the envisioned large-scale biorefinery to produce EL.

Yes / Numerical simulation of wet granulation in a continuous granulator is carried out using Discrete Element Method (DEM) to discover the possibility of formation of seeded granules in a continuous process with the aim of reducing number of experimental trials and means of process control. Simple and scooped drum granulators are utilized to attain homogenous seeded granules in which the effects of drum rotational speed, particles surface energy, and particles size ratio are investigated. To reduce the simulation time a scale-up scheme is designed in which a dimensionless number (Cohesion number) is defined based on the work of cohesion and gravitational potential energy of the particles. Also a mathematical/numerical method along with a MATLAB code is developed by which the percentage of surface coverage of each granule is predicted precisely. The results show that use of continuous granulator is promising provided that a high level of shear is considered in the granulator design, e.g. it is observed that using baffles inside the drum granulators is essential for producing seeded granules. It is observed, moreover, that the optimum surface energy for scooped granulator with rotational speed of 50 rpm is 3 J/m2 which is close to the number predicted by Cohesion number. It is also shown that increasing the seed/fine size ratio enhances the seeded granulation both quantitatively (60% increase in seeds surface coverage) and qualitatively (more homogeneous granules).

Due to the increasing demand for processing low-grade ores, larger volumes of material are being processed. Therefore, the size of flotation equipment has significantly increased for the past decades. The studies related to scale-up are and will remain to be crucial in terms of designing larger flotation equipment. One of the most important factors for flotation scaling-up is the “flotation rate constant”. Hence, the main aim of this investigation was to understand the scale-up criteria when the size of different laboratory-scale cells increases, using the Outotec GTK LabCell®. This was done by assessing the influence of impeller speed, as a hydrodynamic variable, on the flotation performance. Recovery was found to increase with an increase in the cell area to rotor diameter ratio. Flotation rate and recovery increased with an increase in the impeller speed until a certain point that it eventually decreased for the 2 l and 7.5 l cells. For the 4 l cell, the flotation rate and recovery decreased with increasing the impeller speed. The impeller speed of 1200 rpm allowed a successful scale-up based on the flotation rate constants and recovery when increasing the size of the cells. Maintaining the impeller speeds constant at 1300 rpm increased the flotation rate constants and recovery when increasing the cell size from both the 2 and 4 l cells to the 7.5 l cell. A further increase in the impeller speed to 1400 rpm also produced the flotation rate constants and recovery to increase as the cell size increased from both the 2 and 4 l cells to the 7.5 l cell. However, when increasing the cell size from 2 l to 4 l, good results were also observed for all impeller speeds. The products concentrate seem to become finer when decreasing the cell size, with only a few exceptions. The recovery of particles larger than 38 μm was found to differ considerably less among the different scales.

This thesis aims at a deeper understanding of Supercritical Fluid Chromatography (SFC). Although preparative SFC has started to replace Liquid Chromatography (LC) in the pharmaceutical industry - because of its advantages in speed and its less environmental impact - fundamental understanding is still lacking. Therefore there is no rigid framework to characterize adsorption or to understand the impact of changes in operational conditions.   In Paper I we demonstrated, after careful system verification, that most methods applied to determine adsorption isotherms in LC could not be applied directly in SFC. This was mainly due to operational differences and to the fact that the fluid is compressible which means that everything considered constant in LC varies in SFC.   In Paper II we showed that the most accurate methods for adsorption isotherm determination in LC, the so called plateau methods, do not work properly for SFC. Instead, methods based on overloaded profiles should be preferred.   In Paper III a Design of Experiments approach was successfully used to quantitatively describe the retention behavior of several solutes and the productivity of a two component separation system. This approach can be used to optimize SFC separations or to provide information about the separation system.   In Paper IV severe peak distortion effects, suspected to arise from injection solvent and mobile phase fluid mismatches, were carefully investigated using experiments and simulations. By this approach it was possible to examine the underlying reasons for the distortions, which is vital for method development.   Finally, in Paper V, the acquired knowledge from Paper I-IV was used to perform reliable scale-up in an industrial setting for the first time. This was done by carefully matching the conditions inside the analytical and preparative column with each other. The results could therefore provide the industry with key knowledge for further implementation of SFC. / This thesis aims at a deeper understanding of Supercritical Fluid Chromatography (SFC). Although preparative SFC has started to replace Liquid Chromatography (LC) in the pharmaceutical industry - because of its advantages in speed and its less environmental impact - fundamental understanding is still lacking. Therefore there is no rigid framework to characterize adsorption or to understand the impact of changes in operational conditions.   In Paper I-II it was demonstrated why most methods applied to determine adsorption isotherms in LC could not be applied directly for SFC. Methods based on extracting data from overloaded profiles should be preferred.   In Paper III a Design of Experiments approach was successfully used to quantitatively describe the behavior of several solutes in a separation system. This approach can be used to optimize SFC separations or to provide information about the separation system.   In Paper IV severe peak distortion effects often observed in SFC were carefully investigated and explained using experiments and simulations.   Finally, in Paper V, the prerequisites for performing reliable and predictable scale-up of SFC were investigated by small and large scale experiments. / <p>Paper 4 ("Evaluation of scale-up from analytical to preparative...") ingick som manuskript med samma titel i avhandlingen. Nu publicerad. </p>