Title Promoter Affiliations Abstract "Spectral flowcytometry (Cytek Aurora)" "Susan Schlenner" "Department of Human Genetics, Digestive Oncology, Translational Research in GastroIntestinal Disorders, Laboratory for Tumor Microenvironment and Therapeutic Resistance (VIB-KU Leuven), Laboratory for Tumor Immunology and Immunotherapy, Adaptive Immunology, Laboratory of Cell Stress & Immunity" "Spectral flow cytometry is greatly outperforming conventional polychromatic flow cytometry and is expected to replace the previous generation technology in the mid-term. The manifold advantages include unprecedented data quality and deep resolution. Here, we wish to implement the Cytek Aurora spectral analyser into the KUL FACS core as the first instrument available in Belgium positioning the KU Leuven as a key reference for cell phenotyping among other applications in biomedical and clinical research. We wish to highlight the urgent need for a high-parameter flow cytometry instrument at the KU Leuven as the single previous generation instrument available represents a serious bottleneck in (a) available analysis bookings and (b) available parameters with the accompanying complications in antibody panel design and downstream analyses. The Cytek Aurora instrument addresses all current shortcomings and will greatly facilitate research in numerous domains at a fraction of the cost of a conventional instrument." "Bayesian and non-Bayesian methods for the elimination of high-dimensional nuisance parameters" "Geert Dhaene" "Econometrics Research Group, Leuven" "Empirical economics makes increasing use of panel data. To control for unobserved heterogeneity (e.g., heterogeneity in technology across firms, heterogeneity in preferences across consumers, heterogeneity across teachers and students in matched student-teacher data), a common practice is to introduce agent-specific parameters (e.g., additive fixed effects) into panel data models. Such parameters are high-dimensional nuisance parameters and, in many models, this leads to an incidental parameter problem: standard estimation methods such as least squares or maximum likelihood fail to consistently estimate the model parameters that are assumed common to all agents. This research proposal seeks to extend recently proposed exact or approximate solutions to incidental parameter problems in the following new and important directions: (i) Bayesian bias corrections of the likelihood function via the posterior predictive density or via refined implementation of bias-reducing priors; (ii) empirical-likelihood based adjustments for incidental parameter bias in the GMM framework; (iii) deriving theoretical bounds on the incidental parameter bias in regression models with censoring (where simulations suggest that the bias is small). To summarize, there are many model and data settings where applied researchers are naturally led to introduce agent-specific parameters. My goal is to provide researchers with reliable methods of inference in those situations." "Inverse characterization of the orthotropic and viscoelastic material properties of lightweight plates using full field guided wave propagation data" "Koen Van Den Abeele" "Physics, Kulak Kortrijk Campus, Soft Matter and Biophysics" "With the advent of the 21st century, climate change-related issues began to play a crucial role in consumer decisions as well as in company objectives. To reduce carbon dioxide emission rates and increase sustainability, companies started to invest more in the development and implementation of advanced materials. Nowadays, lightweight materials such as fiber reinforced polymer laminates and wooden panels offer an alternative for metallic structures in different industrial applications ranging from automotive to construction engineering. Apart from achieving a high structural performance, these materials offer design flexibility which help to achieve the company’s future goals. However, it is important to recap the fact that “everything comes with a price”. On the downside, inherent anisotropy and heterogeneity of multilayered materials lead to complex mechanical behavior, whereas the low mass of certain new engineering materials results in poor acoustical isolation. Moreover, the combination of fibers with epoxy, or wood with glue, leads to appreciable viscoelastic material behavior, which complicates the design and modelling of constructions having proper structural and acoustical characteristics.The doctoral research work presented here aspired to develop a novel nondestructive method that can be employed for anisotropic mechanical parameter inversion of viscoelastic multi-layer lightweight panels. To achieve this goal, the limitations and challenges involved in traditional characterization methods were first reviewed. With this knowledge in mind, an advanced and novel inversion method based on full-field Lamb waves was introduced. Whereas the use of Lamb waves to characterize viscoelastic material properties has been proposed and studied for almost three decades, past experimental hardware limitations held back the measurement of full-field wave propagation field, which is considered to be essential to identify the anisotropic behavior of materials. Thanks to recent technological progress leading to the introduction of 3D scanning laser Doppler vibrometers (SLDV), high resolution and high-quality information can now be acquired about both in-plane and out-of-plane velocity components of the measured surfaces. In the present work, it is shown that this full wavefield propagation information obtained from SLDV measurements is fundamental to invert more accurate and robust values for the viscoelastic stiffness parameters.Following the introduction of the problem and the state-of-the-art of the considered research domain, several advanced numerical models and global optimization methods were introduced and reviewed in view of developing a more accurate and robust inversion method to overcome the limitations of the traditional methods. Next, a novel two-stage inversion algorithm, employing multi-angle information of the dispersive behavior, was proposed. The inversion method was subsequently verified using the input of various numerical studies as well as experiments. Experiments were conducted on different lightweight materials including aluminum, PMMA, carbon and glass fiber reinforced polymer, porcelain stoneware, as well as medium- and highdensity wooden fiberboard plates. The orthotropic stiffness tensor of these viscoelastic materials was obtained with high accuracy and validated with literature results.In order to extend the proposed characterization technique for quasi-real time application, machine learning algorithms were investigated in the last part of this thesis. The accuracy of the inverted stiffness parameters has been reviewed for different material symmetry groups, and the effect of noise on the machine learning algorithms was studied as well. The results confirms that the developed machine learning-based inversion method has the potential to characterize materials in quasi-real time, which is a persuasive benefit for industrial applications." "Analysis of time varying relationships in multi-country monetary time series." "Christophe Croux" "Operations Research and Statistics Research Group (ORSTAT) (main work address Leuven), Research Centre of International Economics, Leuven" "The main goal of empirical macroeconomics is to understand the relationships between macroeconomic variables, such as the gross domestic product (GDP), inflation and interest rates. This allows for better macroeconomic predictions and helps macroeconomic policy makers to set a sound fiscal and monetary policy. For example, understanding the effect of the short term interest rate on inflation is essential for a central bank, which is responsible for price stability. Also, good GDP predictions allow governments to anticipate the future evolution of the economic activity by taking stabilizing actions in advance.Empirical macroeconomic analysis usually starts from a time series dataset in which the variables of interest are observed for subsequent time periods, typically quarterly. Such datasets thus consist of historical data, where the observations are realizations of how the economy has behaved in the past, and which makes it difficult to derive causal relationships between the variables. In contrast, note that in experimental data, used in for instance pharmaceutical studies, cause and effect can be clearly distinguished by exogenously manipulating a variable, for example the intake of a certain drug, and then observing the consequences on another variable, for example the patient’s health. Still, also information on the linkages between macroeconomic variables can be obtained. First, instead of true causality, macroeconomists often study the incremental predictive power between variables instead, which is called ‘Granger causality’. A variable is said to Granger cause another variable if it improves the prediction of the other variable. Second, macroeconomists often make additional ‘identification assumptions’ on the causality between the variables, which allows them to extract exogenous shocks. One popular identification assumption is the ‘recursive ordering scheme’, in which the ordering of the variables determines how rapidly the different variables can react to exogenous shocks in the other variables. For example, it is typically assumed that inflation and GDP are relatively sluggish variables, such that they do not immediately react to an interest rate shock.In order to extract patterns from the macroeconomic dataset, statistical models are used. In this thesis, we mainly use the Vector Autoregression (VAR) model, which is the workhorse in empirical macroeconomics to study linear relationships between multiple time series. Unlike more structural economic models, VAR models are fully data-driven and require no ex-ante expert knowledge on the dependencies between the variables. In the VAR model, each variable depends on both the past values of the variables in the model and a shock. The vector autoregression coefficients thus represent the effects of past values of the variables on the current value of each variable. While the standard VAR model assumes that these coefficients stay the same over time, this thesis focuses on modeling changing macroeconomic relationships. First, Time Varying Parameter Vector Autoregression (TVP VAR) models allow the vector autoregression coefficients to evolve smoothly over time. For example, the effect of an interest rate shock on inflation is found to be different in the 1970s compared to the period afterwards. Second, frequency domain techniques describe the time series as a weighted sum of sinusoidal components with different frequencies, for instance slowly fluctuating and quickly fluctuation. Interestingly, the relationships between the variables can differ across these different frequency components. Third, for a panel dataset in which the variables are observed both for subsequent time periods and different countries, also the cross-country variation in the coefficients can be analyzed.This thesis contains essays on the empirical relationship between macroeconomic time series, often in a multi-country setting. While the standard VAR model is used in Chapter 2, the time variation in the coefficients is studied in Chapters 3 and 5, the frequency domain analysis is performed in Chapter 1 and the cross-country variation is analyzed in Chapter 4.The first chapter studies the predictive power of domestic stock prices for the future domestic economic activity in the frequency domain. We develop a multi-country test for Granger causality for each of the frequency components. Using 1991Q1-2010Q2 quarterly data for the G-7 countries, we report that the slowly fluctuating components of stock prices have large incremental predictive power for the future GDP, while this is not the case for the quickly fluctuating components.The second chapter analyzes impulse response functions of vector autoregression models for variables that are linearly transformed. The impulse response function of a vector autoregression model is an often used tool in empirical macroeconomics to analyze the response of the variables in the model to different types of shocks. For many empirical applications, it is of interest to know how the impulse response functions would change if one or more variables in the VAR model are replaced by a linear transformation of the original variables. One example of such a transformation is the replacement of a nominal growth rate variable in a VAR model that also includes inflation by its corresponding real growth rate variable, which is the difference between the nominal growth rate variable and inflation. We show that the new impulse response is equal to the linear transformation of the original impulse response if and only if the new shock is equal to the linear transformation of the original shock. Sufficient conditions for this relationship between impulse responses are derived for the setting where the same type of shock is studied in the linearly transformed and original model. In particular, we consider shocks in one error term only, orthogonalized shocks and generalized shocks.The third chapter compares Bayesian estimators with different prior choices for the amount of time variation in the coefficients of time varying parameter vector autoregression models using Monte Carlo simulations. In Bayesian statistics, the posterior estimate of the parameters in the model is a combination of, on the one hand, the prior assumption on the distribution of these parameters and, on the other hand, the information contained in the data. When the sample size is very large, the prior specification is not that important as it is swamped by the large amount of information in the data. However, for typical macroeconomic time series, the prior is very important. Since the commonly used prior only allows for a tiny amount of time variation, less restrictive priors are proposed. Additional empirical evidence on the time varying response of inflation to an interest rate shock is then provided for USA: while a major and statistically significant ‘price puzzle’ is detected for the period 1972-1979, the estimated response of inflation to an interest rate shock is negative for most other time periods.The fourth chapter investigates empirically how the impact of a residential house price shock on household credit and GDP is influenced by the degree of the mortgage market flexibility. Countries with a flexible mortgage market, such as United States and United Kingdom, are characterized by a high loan to value ratio, low transaction costs of mortgage refinancing and easy access to second mortgages and home equity loans. Countries with an inflexible mortgage market, such as France and Italy, are characterized by the opposite. We hypothesize a stronger effect of house price shocks for the former countries because the financial accelerator mechanism for existing home owners is expected to be stronger and because the effect of higher house prices on the required amount of savings of future first time house buyers is expected to be smaller. A panel vector autoregression model is estimated separately for a group of eight countries with a flexible mortgage market and for a group of eight countries with an inflexible mortgage market. While both household credit and GDP increase after a positive house price shock for both groups of countries, we do not find empirical evidence that these responses are stronger for countries with a flexible mortgage market.The fifth chapter investigates the determinants of sovereign credit ratings, which are ordinal measures of the creditworthiness of a sovereign government assigned by a rating agency. We quantify for the three major credit rating agencies how the importance of the different sovereign credit rating determinants changed after the start of the European debt crisis in 2009. For this end, we estimate a multi-year ordered probit model, using a sample of 90 countries for the years 2002-2015. Our model allows for time variation in the importance of the different determinants and it takes into account the ordinal nature of the credit rating. We provide empirical evidence that the credit rating agencies changed their sovereign credit rating assessment after the start of the European debt crisis in 2009. The financial balance, the economic development and the external debt became substantially more important after 2009 and the effect of Eurozone membership switched from positive to negative. In addition, GDP growth gained a lot of importance for highly indebted sovereigns and government debt became much more important for countries with a low GDP growth rate.In the epilogue chapter, I give my personal view on the way statistical inference should be used in business and economic applications. In particular, I call for more focus on the evaluation of ‘economic importance’, i.e. the estimated magnitude of an effect together with its estimation error, and for less focus on the often less relevant and frequently misunderstood concept of ‘statistical significance’, which only informs on the existence of the effect." "On the Multi-scale Vibroacoustic Behavior of Multi-layer Core Topology Systems" "Mohamed Ichchou, Wim Desmet" "Mecha(tro)nic System Dynamics (LMSD)" "In this last decades, honeycomb sandwich panels have been the subject of intensive researches. Indeed, their high mechanical performances combined to a low stiffness to weight ratio result in a reduced acoustic efficiency.  Therefore, many designs are usually proposed to overcome this issue. Besides, different methods are developed to model more complex structures using the periodic structure theory to study the wave propagation allowing to investigate the vibroacoustic parameters.The main purpose of this thesis is to investigate the vibroacoustic multi-scale behavior of multi-layer core topology systems which consist on stacking layers of honeycomb cores leading to an impedance mismatch between layers. In addition, such structures allow to increase the design space up to now limited to standard sandwich panels made of a single honeycomb core. Therefore, it is possible to obtain many configurations keeping the mass constant with simple shifting process between layers. A parametric model is proposed allowing to extract the unit cell through the thickness of the panel and to apply the periodic structure theory.Modelling multi-layer core topology systems has been performed using the wave finite element method, and an extended method has been proposed to solve the acoustic transmission problem. The study is focused on transition frequencies, the sound transmission loss as well as veering effects and internal resonances, to finally optimize the geometrical parameters and to analyze their influence on the acoustical and mechanical performances of the structure.Although the out-of-plane compression properties of multi-layer core topology systems are reduced, it is possible to strongly improve the in-plane compression properties. These later are studied by comparing a multi-layer hexagonal core and a standard single hexagonal core.Finally, using multi-layer core topology systems and a perforated upper skin, it is possible to increase the energy dissipation occurring inside the core and thus, improve the sound absorption coefficient. Therefore, the thermo-viscous effect is considered. The acoustic behavior is similar to porous media and the Johnson-Champoux-Allard parameters are retrieved to characterize the acoustic fluid flow.An improvement of the sound transmission loss and the sound absorption coefficient is obtained in a broadband frequency and the obtained resonance frequencies can be modified. However, this leads to lower mechanical properties especially the compression modulus and the dynamic rigidity.Keywords: multi-layer core systems, vibroacoustic, transmission loss and sound absorption coefficient, transition frequency, veering, optimization." "Highly efficient perovskite-based multijunction solar cells and modules" "Jef Poortmans" "ESAT - ELECTA, Electrical Energy and Computer Architectures, Electrical Energy Systems and Applications (ELECTA)" "With solar panels costs and prices falling rapidly, the major capital cost is nowadays related to the balance-of-system (BOS), which includes inverters, cables, mechanical supports and other area-related costs. Therefore, the photovoltaics (PV) industry has shifted focus from the panel’s costs themselves to the need for higher power conversion efficiencies in order to reduce the cost per watt peak (Wp) installed. Moreover, there is an increasing number of applications with limited surfaces, such as building integrated photovoltaics, solar cars, drones... where the efficiency of the panels becomes the most important parameter. However, the mainstream silicon technology has almost reached its theoretical limits and the most promising solution to overcome this limit is to stack different solar cells technologies (tandem cells) one on top of the other to use the solar spectrum in a more efficient way. In this regard, perovskites have shown to be interesting low-cost candidates for tandem solar cells due to their tunable absorption characteristics and high-power conversion efficiency. As the research on the topic has just started, the objectives of this research are to gain fundamental understanding of the limits that hinder the commercialization for the promising perovskite-based tandem solar cell technology and to overcome them." "Synthesis and processing routes of porous materials from Fe-rich slags" "Yiannis Pontikes" "Sustainable Metals Processing and Recycling" "The doctoral dissertation will be a part of the SBO project “Geopolymers and Hybrid Cements for Roads and Tunnels” (GHRANTE). The main goal of the project is “to develop innovative, recyclable inorganic polymers-based materials from residues of the non-ferrous metallurgy”. The goals of within those WPs are: WP1: To develop inorganic polymers containing Ca and/or Fe that incorporates the target residues. WP4: To develop a sound absorptive highway panel with satisfactory durability and resistance using inorganic polymers or hybrid cements. The research will start by the analysis of a suitable precursor for inorganic polymers (IP). This involves the characterization and reactivity assessment, reaction kinetics and study of the binder properties (WP1). The outcome of this WP will be used as a starting point for the core research of the doctoral dissertation, which is the development of a highly durable and resistant sound absorbing highway panel (WP4). This material is conceived as a highly porous matrix, which will allow the absorption of the sound waves. The production of such material will be explored by several techniques and parameters. Chemical foaming and the introduction of lightweight aggregates correspond to some of the tasks within the work. After optimization of the properties in terms of acoustic absorption, the design a layered acoustic panel is aimed, using a dense layer of IP with at least 2 layers of porous IP." "Increasing the range for chickens in use by mobile houses, combined with the production of short rotation coppice" "Frank Tuyttens" "Department of Veterinary and Biosciences, Dean's Office of the Faculty of Veterinary Medicine" "Chickens with free-range access often make limited use of their free-range area; a small part of the flock is usually observed outside at any given time, and those that are outside prefer to stay close to their houses. As a consequence, the claimed welfare benefits of free-range use may not be achieved, and nutrient loads in the soil are very high close to the chicken houses. The low range use may have several reasons, such as fear of a novel environment, adverse weather conditions, or low motivation to explore. This thesis aimed to assess the effects of combining slow-growing free-range broiler chickens with short rotation coppice willows (SRCW). These are fast-growing trees that are used for biomass production. They could provide a good ranging environment to the chickens, and be an extra source of income for the poultry farmer. It was assessed how SRCW and artificial shelter influenced free-range use, leg health, fearfulness and meat quality. In addition, two rearing strategies were tested aimed at improving free-range use. Furthermore, a new system was developed to automatically monitor free-range chickensU+2019 position. Finally, the interactions between chickens, SRCW and soil parameters were assessed. Factors affecting and being affected by free-range use In Chapters 2, 3 and 4 the relationships between free-range use and shelter types were studied. In Chapter 2, slow-growing broiler chickens (Sasso XL451) were given outdoor access either to an area with grassland and artificial shelters (wooden A-frames; AS) or to an area with SRCW. In all studies in this thesis, birds were given outdoor access approximately between four and ten weeks of age. The groups with access to SRCW had higher mean percentages of birds outside (42.8% vs. 35.1%), and more birds that ranged farther than 5 m from the house (10.6% vs. 4.1% of all birds outside). In Chapters 3 and 4 the birds were given access to both AS and SRCW. This revealed that birds had a strong preference for SRCW, with more birds ranging in this shelter type and with birds going farther from their house. In Chapter 4, an additional shelter type was provided, i.e. overhangs adjacent to the pop holes. It was hypothesised that these would result in a more gradual transition between the indoor and outdoor environment, and therefore in more free-range use. However, no such effect was found, neither were overhangs related to a difference in the behaviours that the birds displayed. The effects of weather conditions on free-range use were studied in Chapters 2 and 3. If birds had access to either AS or SRCW (Chapter 2), rainfall, increasing solar radiation and increasing wind speed were negatively related with the number of birds outside, and these effects were more pronounced in SRCW. This could indicate that SRCW provides less protection against these weather conditions than the A-frames, but possibly this result was due to more birds being outside in SRCW, so more birds could go inside during adverse weather. If birds had access to both AS and SRCW (Chapter 3), rainfall and decreasing solar radiation were related to finding more birds outside in AS, whereas the opposite was true in SRCW. This suggests that SRCW provides better protection against solar radiation than AS, and that birds chose to seek shelter in the vegetation instead of in their house if they have the opportunity. In this case, increasing wind speed was related to less birds outside in both shelter types. In both chapters, an increasing temperature was related to more birds being outside. The relationships between free-range access and fearfulness and leg health were studied in Chapter 2. In addition to the birds with access to either AS or SRCW, there were also groups that were kept indoors (IN) for the entire production period. In week 3 (i.e. before outdoor access was provided), birds were subjected to a tonic immobility (TI) test (gives an indication of the level of fearfulness), and this test was repeated in week 10. A longer TI duration in week 3 was associated with more birds farther than 5 m from the house, but not with the mean number of birds outside. TI duration in week 10 was not associated with either of these, but the number of inductions needed was higher in SRCW than in IN groups. These findings suggest that there is a negative relationship between fearfulness and free-range use, but more studies, e.g. on individual birdsU+2019 data, are needed to confirm this. Gait problems tended to occur more in IN than in AS birds, and hock dermatitis occurred more in IN than in AS, and tended to occur more in IN than in SRCW. The behaviours of the birds in relationship to the shelter types were studied in Chapters 3 and 4. This revealed that relatively more birds were foraging in AS, but because the total number of birds was always higher in SRCW, the absolute number of birds foraging was also higher in SRCW. Foraging occurred more at >5 m from the house than closer by, possibly due to depletion of vegetation in proximity of the houses. Sitting occurred more close to the houses, and in SRCW, which may be attributed e.g. to a more favourable microclimate or a greater sense of safety due to more cover. In Chapters 3 and 4, two rearing strategies were tested: providing environmental enrichment and providing access to dark brooders early in the chickensU+2019 lives. Both were provided from day 0 until the birds were moved to mobile houses in week 4. The enrichment consisted of hay bales, scattered grain, strings and live mealworms. Dark brooders are warm, dark, secluded areas in the home pen under which the chicks can rest. There are indications that both 198 environmental enrichment and dark brooders have the potential to decrease fearfulness and increase exploration motivations, which could subsequently lead to better free-range use later in life. In the present study, the enrichment and dark brooders had no relevant effect on TI duration or free-range use. The dark brooders only tended to affect the number of birds that jumped in an open field test (higher in non-brooded birds). No effects of the dark brooders on behaviour of the birds at later age could be demonstrated, and only minimal effects of the enrichment on behaviours were found. In Chapter 5, the effect of free-range use on production and meat quality was assessed. The treatment groups used were the same as in Chapter 2 (IN, AS, SRCW). At slaughter age (d72), IN birds were heavier than AS and SRCW birds, but no differences in feed intake or feed conversion were found, possibly due to unregistered feed intake (vegetation, insects, small vertebrates) by the AS and SRCW birds in the free-range areas. Breast meat of chickens with free-range access was darker and yellower than that of IN chickens. Ultimate pH was lower and drip loss higher in IN versus AS chickens. The percentage of polyunsaturated fatty acids was higher in AS than in IN meat. A blinded taste panel judged breast meat of SRCW chickens to be more tender and less fibrous compared to that of AS and IN chickens, and juicier compared to the IN chickens. Automated positioning system Chapter 6 describes the performance of a newly developed automated positioning system to monitor free-range chickensU+2019 position. This Ultra-Wideband (UWB) system consists of active tags (attached to the chickens) that send signals to anchors positioned at fixed locations in the field; the tagsU+2019 position can be calculated using the time of arrival of its signal, if this is registered by at least three anchors. Its accuracy and registration success, as well as which factors may affect its performance, were assessed. The effects of vegetation type, precipitation, tags being mounted on a chicken, tag height, angle and orientation, coverage by A-frames or mobile chicken houses, and proximity of other tags on accuracy of the registered positions (distance between the registered and the true position of the tag) and on registration success (percentage of registrations where a position could be calculated) were assessed. Overall, the median error was 0.29 m, and the mean percentage of successfully registered positions was 68%. None of the variables had a clear effect on the accuracy of the positions. Errors were generally larger in certain areas of the experimental field, which may be due to the asymmetrical setup of the anchors. The percentage of successful registrations was negatively affected by shelter type, with lower percentages in dense vegetation (short rotation coppice willows) than on grassland, possibly due to malfunctioning of two anchors close to the SRCW plots. Rain and placing the tags underneath a wooden A-frame, but not placing them in a mobile house, resulted in a lower percentage of successful registrations. The tag being mounted on a chicken, height and angle of the tag and proximity of other tags had no negative effect on the percentage of successful registrations. Placing more (functioning) anchors may contribute to better accuracy and registration success. Alternatively, the bias resulting from the variables that had a negative effect on registration success should be corrected for when using the system in its current setup. Overall, this system shows great promise to be used for monitoring chickensU+2019 free-range use. Interactions between chickens, SRCW and soil parameters In Chapter 7, the interactions between slow-growing broilers, SRCW and soil parameters were studied. The experimental field was split up into four quadrants: two were sown with a grass/clover mixture, two were planted with SRCW (three clones, i.e. Tora, Tordis and Klara) and clover as undergrowth. SRCW was harvested 1 and 4 years after establishment. Chickens were present on the field during parts of each year (see Chapters 2, 3 and 4), and parts of the field were kept chicken-free as a control. Free-range use, SRCW growth and soil parameters were monitored on a regular basis over a 4-year period. No effects of chicken presence on SRCW growth were observed. Total mineral N (Nmin) was affected by vegetation type x location x depth; it was generally higher in SRCW than in grassland, in areas close to the chicken houses, and in more superficial soil layers. This could be due to return of N through leaf fall, as opposed to grass which is mown and removed. SRCW was also harvested eventually, but the amount of N removed through this process was lower than that removed by mowing the grassland. In addition, higher Nmin levels could be due to the higher chicken density in SRCW (more N deposition through faeces), to NH3 being captured from the air by the trees, to the strong clover development under SRCW (which can fix atmospheric N), and to the lower N requirement of SRCW compared to grassland. Nmin did not appear to accumulate in the soil over the years, but close to the chicken houses there were indications for nitrate leaching to deeper soil layers and possibly to groundwater. K and PCaCl2 were higher close to the chicken houses, probably due to high concentrations of these nutrients in chicken faeces. No increase in soil organic C was observed over the four-year experimental period, and no differences were found between SRCW and grassland. This could be due to the short time period that SRCW was present. In conclusion, SRCW was preferred by the chickens, but the possible leaching of nitrate to ground water close to the houses and possible remediating strategies for these need to be studied further. Conclusions From this thesis it can be concluded that SRCW and broiler chickens can be combined in order to promote free-range use: birds preferred SRCW over AS, and ranged further from their house in the former, without having an effect on SRCW production. Overhangs adjacent to the pop holes were not successful in promoting free-range use. The provision of environmental enrichment or dark brooders early in the birdsU+2019 life did not affect free-range use later in life. Free-range access may be associated with better gait and less hock dermatitis, as well as with changes in meat quality such as a more pronounced yellow colour and more tender and less fibrous meat. Individual free-range use monitoring would possibly elucidate these relationships further. The automated positioning system that was developed showed promise for use in future research. There could be some bias between different vegetation types, with tags in SRCW being detected less often than those in grassland, although this was probably at least partially due to problems with anchors next to the SRCW plots. Combining broiler chickens with SRCW resulted in high levels of N and P in the soil, especially close to the chicken houses. This can result in leaching of these nutrients to groundwater, and calls for further research." "Development of Inorganic Polymers for Near-zero Energy Dwellings" "Carlo Pellegrino, Yiannis Pontikes" "Sustainable Metals Processing and Recycling" "Alkali activation has been emerging as a sustainable technology to produce innovative construction materials. Alkali-activated materials have been extensively investigated, but different levels of scientific understanding and industrial implementation can be found among several subgroups of such materials.The most widely examined alkali-activated materials are commonly known as geopolymers. The scientific knowledge of their reaction mechanisms and structures is mature, and their market implementation fairly consolidated. Conversely, inorganic polymers (IP) is a different subgroup of alkali-activated materials since their chemistry does not exactly correspond to the definition of geopolymers. These systems are challenging but unlikely geopolymers can admit a wide range of precursors offering an opportunity to valorize low-value raw materials that include several wastes and industrial by-products. The diversity of precursors that can be used in IP production hinders the definition of production guideposts, and dedicated research is needed to define ad hoc mix designs according to the precursors’ characteristics and envisioned applications.This doctoral research was focused on the multiscale development of inorganic polymers and the conceptual design of sustainable and multifunctional materials for near-zero energy-consuming buildings. Vitrified residues produced during the thermochemical conversion of refused derived fuel were taken as a representative case study of a broad group of currently underutilized industrial by-products, namely calcium-iron-rich slags.The aim of this work was to understand the fundamental processing parameters affecting the reaction mechanism involved in the formation of calcium-iron-rich IPs and their correlation with the chemical and physico-mechanical properties of the developed materials. The major technological constraints related to the use of such slags as IP precursors were examined, and the most suitable production conditions to obtain IP products with enhanced properties identified. A broad range of IP materials with engineered properties was developed and optimized. The efforts made in developing predictive models, in optimizing mixture proportions and in minimizing the shrinkage of IP binders and mortars are described. Optimized products characterized by a high dosage of residues in their composition, increased volumetric stability, excellent mechanical properties, and good residual properties after exposure to high temperatures were developed. The functionalization of IP mortars was addressed, and the effects of incorporating phase change materials in the mix design investigated. Lightweight IPs were developed using different processing routes, and their mechanical and thermal properties examined.Different IP products were used to develop multi-layer sandwich panels that were both thermal insulating and reactive to temperature fluctuations. The problematics related to their upscaling were analyzed, and the production processes optimized. Semi-industrial sandwich panels were produced to demonstrate the feasibility of the solutions proposed.The topic analyzed in this doctoral research and the insights provided are a significant contribution to the implementation of alkali-activation technology as a viable upcycling solution for industrial by-products, and particularly interesting to the construction sector in which current efforts to achieve lower environmental impacts are considerable. The use of calcium-iron-rich slags, like the ones produced in thermochemical conversion processes, in such production schemes is a plausible large-scale upcycling route that can absorb significant volumes of those residues and, by doing so, contribute to increasing the sustainability of industrial sectors in which such residues are produced." "Design of automotive sound packages in the mid-frequency range" "Wim Desmet" "Production Engineering, Machine Design and Automation (PMA) Section, Mecha(tro)nic System Dynamics (LMSD)" "The pursuit for green, affordable and comfortable cars has pushed the automobile manufacturers to balance the mass, the cost and the performance of every component. This is notably valid for sound packages, which are key components to the interior noise and vibration performance. Their design for the low- and high-frequency range is well established. However, the design for the mid-frequency range (100-1000 Hz) is more difficult, because of the mixed contributions of airborne and structureborne noises, the lack of representative performance metrics and the high computational cost of the simulations. Because of those difficulties, the design process of sound packages in the mid-frequency range is not streamlined. Eventually, the performance for the mid-frequency range mostly relies on the evaluation on an actual vehicle, which is available at a late stage, when the freedom to modify the design is low.To develop the sound packages for the mid-frequency range, a framework has been implemented. It consists in a V-shape process to breakdown the interior noise and vibration performance targets to the inputs and body, and finally to the sound package design. This dissertation focuses on the development of tools and guidelines to support the design of the sound packages.Performance metrics for sound packages in the mid-frequency range are investigated. Two transmission metrics are selected: the first one quantifies the losses in terms of velocity transmission through the panel and the second through the silencer. Additionally, a structureborne back-coupling metric is developed to quantify how the sound package accepts a certain structureborne input.A framework to compute performance maps of sound packages is proposed. This framework embeds a model order reduction method to speed up the simulations and a surrogate modelling method to reduce the number of designs. The surrogate model is used based on a Kriging method, which is iteratively enriched with new designs to increase the accuracy of the fitted model. Each new design consists of a finite element simulation of a sound package in the mid-frequency range, with porous layers based on the Biot formulation. To gain computation time, it is run using a reduced order model based on a Krylov projection matrix-free algorithm: from a limited set of frequency lines, each metric is approximated by a reduced model using rational functions. Through an iterative enrichment, new frequency lines are added until sufficient accuracy is achieved on all the metrics.An experimental validation of this framework is carried out. 47 specifications of sound packages are tested on a structureborne set-up and their numerical counterpart is simulated by the finite element method. These explicit simulations are correlated to the measurements in local transfer function in values and in main effects of two design parameters.A structureborne application of this framework on a typical sound package is presented. Both material and geometrical parameters are considered to build a parametric response surface of the performance in the mid-frequency range. From a limited number of designs, the framework could build surrogate models representing the three metrics. Two types of guidelines are extracted: (1) guidelines to get the best performance under mass and height constraints; (2) guidelines in terms of ranges and slopes for each parameter. The robustness of these guidelines is assessed."