<p>Vertical farming (VF) as a newer sector of controlled-environment agriculture (CEA) is proliferating as demand for year-round, local, fresh produce is rising. However, there are concerns regarding the high capital expenses and significant operational expenses that contribute to fragile profitability of the VF industry. Enhancing resource-use efficiency is a strategy to improve profitability of the VF industry, and different approaches are proposed in the three chapters of this dissertation. LEDs are used for sole-source lighting in VF, and although they recently have significantly improved electrical efficiency and photon efficacy, the Lambertian design of the illumination pattern leads to significant loss of obliquely emitted photons beyond cropping areas. In chapter 1, close-canopy lighting (CCL) is proposed as one effective energy-saving strategy, through which unique physical properties of LEDs were leveraged, and two CCL strategies (energy efficiency and yield enhancement) were characterized at four different separation distances between light-emitting and light-absorbing surfaces. Dimming to the same light intensity at all separation distances resulted in the same biomass production while significant energy savings occurred at closer distances. Significantly higher light intensity and yield were achieved under closer separation distances in the yield-enhancement strategy for the same energy input. The energy-utilization efficiency (g fresh/dry biomass per kWh of energy) was doubled in both scenarios when the separation distance between LED emitting surface and crop surface was reduced maximally. At reduced separation distances, the chance of photon escape from growth areas is less, and canopy photon capture efficiency is improved.</p><p>Optimizing environmental conditions for indoor plant production also helps improve resource-use efficiency for the nascent vertical-farming industry. Although significant technical advancements of LEDs have been made, use of efficient far-red (FR) LEDs has yet to be exploited. As a recent proposed extension to traditional photosynthetically active radiation (PAR, 400-700 nm), FR radiation (700-750 nm) contributes to photosynthesis as well as photomorphogenesis when added to shorter wavelengths of traditional PAR. However, the interaction of FR with other environmental parameters such as CO2 is less studied. In chapter 2, the interaction effect of four FR fluxes (as substitution for red) in combination with three different CO2 concentrations were investigated at three distinctive stages of young-lettuce production. The highest biomass achieved at all stages occurred at 800 mmol mol-1 CO2 compared to 400 and 1600 mmol mol-1. A photomorphogenic effect of FR to promote leaf length was pronounced at the earliest stages of development, at which FR did not contribute to higher biomass accumulation. At more developed stages, 20 mmol m-2 s-1 of FR substituting for red contributed to biomass accumulation similar to shorter wavelengths of traditional PAR, whereas higher fluxes of FR in the light recipe resulted in undesirable quality attributes such as longer leaves.</p><p>Optimizing environmental conditions for indoor production with emphasis on light intensity and CO2 concentration at four distinctive stages of lettuce production was investigated in chapter 3. Utilizing the Minitron III gas-exchange system, light and CO2 dose-response profiles were characterized at four distinctive crop-development stages through instantaneous gas-exchange measurements at crop level. At all developmental stages, as CO2 concentration increased, photosynthesis increased up to 500 mmol mol-1, above which the incremental rate of photosynthesis was reduced. Light-dose response profiles were characterized at 400 or 800 mmol mol-1 CO2, and as light intensity increased, photosynthesis increased up to 650 mmol m-2 s-1. However, when instantaneous power (Watts) consumed for lighting was taken into consideration, power-use efficiency as the ratio of output photosynthesis increment to input power increment (to increase light intensity), decreased at higher light intensities. Vertical farming as a nascent and growing industry is facing limitations including marginal and even elusive profitability. Optimizing environmental conditions for indoor plant production such as these will help improve resource-use efficiency and profitability of the vertical farming industry.</p>

Daylight harvesting is an essential strategy that is often used to enhance both the design and performance of an architectural project. Windows, as crucial architectural elements, not only admit natural light into spaces but also provide the occupants with visual connections. However, the excessive usage of windows brings an uncontrolled amount of solar energy to the spaces and negatively affect the building's energy performance. When utilizing passive design strategies such as daylight harvesting, several parameters, including the electrical lighting system, can impact the outcome. The current study investigates the role of lighting systems on daylight harvesting's effectiveness and their impact on window dimension and total energy consumption. In this study, the optimum window-to-wall ratio of an open office in the presence of two different light sources (LED and fluorescent) is explored through a computer simulation method. A combination of tools including AGi32, ElumTools, OpenStudio, EnergyPlus, Radiance, and MATLAB helps to conduct the simulation and deliver optimal results. In the results and conclusion chapter, the study provides guidelines to specify optimal window percentages considering two lighting systems in each cardinal direction. Importantly, the guideline focuses only on energy performance and not on the spatial quality of the design. / Master of Architecture / Harnessing daylight with the use of windows helps to offset parts of the electric lighting needs, and decrease the total building energy consumption. This is accomplished by using glazed materials to admit daylight and lighting control systems, which can respond to the dynamic light level. However, improper implementation of a passive daylighting strategy may cause increased energy consumption. Sunlight is accompanied by solar heat radiation which can increase the HVAC load of a space and compromise the energy savings achieved by daylighting. Therefore, a balance between solar heat and light gain is required to fully take advantage of solar energy without reverse impacts. Concerning the mentioned balance, recent advancements in lighting technology question the effectiveness of natural light in reducing whole-building energy consumption. Due to the high energy efficiency of LED luminaires, lighting power consumption is rather low, even when the lighting system operates at full capacity. Therefore, it is unclear whether the solar energy coming through glazed materials works to the advantage or disadvantage of total building energy consumption. This study hypothesized that the total energy consumption of an open office with LED luminaires would be less in absence of solar energy compared to a scenario which utilizes the solar energy. A simulation-based methodology, using a combination of photometric computation and building energy simulation tools, was utilized to examine the hypothesis and explore the impacts of lighting systems on the optimum window-to-wall ratio. The results provide a helpful guideline which highlights the impact of lighting systems on window dimensions and their mutual effect on whole-building energy consumption. Although the optimum window-to-wall ratios suggested by this study only concern energy consumption, integration of them with occupants' preferences can propose an acceptable window-to-wall ratio that satisfies both design quality and performance of a building.

Ce travail de thèse porte la synthèse et la caractérisation d’un luminophore rouge inorganique sans terres rares de formulation Na2SiF6 : Mn4+. Un protocole de synthèse originale des matrices fluorures A2MF6 : Mn4+ (A = Na, K ; M = Si, Ti) par un procédé sol-gel a ainsi été mis au point. Cette synthèse brevetée et industrialisable permet d’obtenir des composés avec un rendement quantique absolu supérieur à 50% sous excitation LED bleue. Plusieurs analyses structurales, microstructurales, et à sondes locales ont permis de caractériser précisément les composés synthétisés. Le deuxième volet important de ce travail a été la construction d’une enceinte de vieillissement permettant de suivre l’évolution des propriétés de luminescence des luminophores en fonction du temps sous l’effet combiné d’un stress hydrique, thermique et photonique. Les mesures, entièrement automatisées, nous ont permis d’établir des lois cinétiques de dégradation du flux lumineux à partir desquels des facteurs de maintenance (L90, L70, L50, etc…) ont pu être déterminés. De plus, un mécanisme de dégradation de cette famille de luminophores a été proposé. Finalement, un prototype d’éclairage à base de LEDs bleues intégrant une couche de conversion constituée des luminophores Na2SiF6 : Mn4+ et YAG : Ce3+, Gd3+ a conduit à des caractéristiques très prometteuses. / This PhD work deals with the synthesis and characterization of a rare earth-free inorganic red phosphor of Na2SiF6: Mn4+ formulation. An original synthesis protocol of fluoride matrices A2MF6: Mn4+ (A = Na, K, M = Si, Ti) by a sol-gel process has been developed. This patented and industrializable synthesis allows to obtain compounds with an absolute quantum yield greater than 50% under blue LED excitation. Several structural, microstructural and local probe analyzes have made it possible to precisely characterize the synthesized compounds. The second important part of this work was the design of an aging chamber to follow the evolution of phosphor luminescence properties as a function of time under the combined effect of hydrous, thermal and photonic stress. Measurements, fully automated, allowed us to establish kinetic laws of luminous flux degradation from which maintenance factors (L90, L70, L50, etc. ...) could be determined. Moreover, a degradation mechanism of this family of phosphors has been proposed. Finally, a blue LED lighting prototype incorporating a conversion layer consisting of Na2SiF6: Mn4+ and YAG: Ce3+, Gd3+ phosphors led to very promising characteristics.

In this diplomat theses are considered the effects of light on human beings, especially on physical performance. The goal of this work was to design a suitable method for evaluation of the effects of light on physical performance. Furthermore, to verify designed methods in laboratory environment and the assessment of collected data. After creating this method several people were tested under different light conditions and collected date evaluated. The results are suggesting that high intensity lighting with low wave lengths leads to an increase of physiological activity in organism and therefore to a potential decreasing physical performance.

This work deals with the design and implementation of Wi-Fi LED lighting. It consists of various modules - switches, buttons, single or multicolored light sources - and a central unit that provides mutual communication and automation. The result of the work is the design of a prototype and several modules, which are built on the basis of the microcontroller ESP32. Their utility is implemented in C++. The user interacts through the website. The main result of this thesis is a demonstration of the possibility of using Wi-Fi to control light sources and creating complex lighting using a combination of simple modules and rules.

The aim of this diploma thesis is assessment of options to reduce energy consumption in industrial areal belonging to Fritzmeier company. This thesis is divided into three parts. In the first part there is analysis of electrical energy and natural gas consumption in considered industrial area based on data from energy audit. The second part consists of short theoretical elaboration of cogeneration and cogeneration technologies, design of five variants of use of cogeneration units with combustion engine running on natural gas and evaluation of proposed variants. Third part of this thesis is about modernization of lighting system in small section of assembly hall. In this part parameters of new LED lighting system for selection are set, based on theoretical elaboration of LED problematics and five variants offered by specialized companies are evaluated.

Mehr als 90% eines Tages verbringen Europäer im Durchschnitt innerhalb von Gebäuden. In der Vergangenheit orientierten sich die Empfehlungen für Innenbeleuchtung überwiegend an den visuellen Anforderungen. Wenn man aber von einer evolutionären Anpassung des Menschen an natürliche Lichtbedingungen ausgeht, müsste sich die Nachbildung von natürlichen Lichtbedingungen, die über die visuellen Anforderungen hinausgehen, in der künstlichen Raumbeleuchtung positiv auf Befinden und Leistung auswirken. Diese Arbeit geht der Frage „Welche Eigenschaften des natürlichen Lichts sind wichtig und sollten bei der Innenbeleuchtung nachgebildet werden?“ auf den Grund und leistet mit neuen Erkenntnissen zur Lichtwirkung einen Beitrag zur Wissenschaft. Das zentrale Ziel dieser Arbeit ist die Beantwortung der Frage, ob sich eine technisch realisierte Lichtexposition, welche nach Qualität und Dynamik dem natürlichen Tageslicht ähnlicher ist als die heutige Standardbeleuchtung, positiv auf subjektive Befindlichkeiten und die Leistungsfähigkeit auswirkt. Ob und welche Dynamiken des natürlichen Lichts bei der Innenbeleuchtung nachgebildet werden sollten, um optimale Arbeitsbedingungen bei der Wissensarbeit zu schaffen, wird aus grundlegenden Untersuchungen zu dynamischem Licht abgeleitet. Schwerpunkt der Untersuchungen sind ultradiane Lichtwechsel.

Cette thèse visait à concevoir et à synthétiser des matériaux hybrides organiques-inorganiques à luminescence contrôlée et à les étudier en tant que luminophores pour l'éclairage à LED. L'objectif final était d'obtenir une source de lumière blanche. En effet, les LED blanches commerciales sont constituées d'un dispositif émetteur bleu recouvert d'un luminophore jaune. La combinaison de ces deux couleurs produit une lumière blanche. Cependant, cette lumière n'est pas de bonne qualité car il lui manque une composante rouge. Cela entraîne un mauvais rendu des couleurs des objets éclairés par ces sources de lumière. Dans notre travail, des polymères conjugués de différentes couleurs d'émission ont été obtenus avec succès. En particulier, plusieurs émetteurs de blanc ont pu être isolés.Dans cette thèse, non seulement les procédures de synthèse et les caractérisations chimiques sont présentées en détail, mais également les études des propriétés photophysiques des polymères, en solution et à l'état solide. Des études à l'état solide ont été effectuées sur les polymères et sur les polymères dispersés dans une matrice polymère. Ces études ont permis d'identifier les facteurs limitants quant aux utilisations pratiques de ces matériaux. Des solutions ont été proposées pour améliorer les performances d’émission et de stabilité des matériaux. De plus, ces travaux ont permis d'introduire la 2,2’-bipyrimidine comme nouvelle unité constitutrice pour le développement de polymères conjugués. / This thesis aimed at designing and synthesizing organic-inorganic hybrid materials with controlled luminescence and at investigating them as phosphors for LED lighting. The final goal was to obtain a white source of light. Indeed, commercial white LEDs are made up of a blue emitting device covered with a yellow phosphor. Combining these two colors yields white light. However, this light is not of good quality as it lacks some red component. This results in a bad rendering of the colors of objects illuminated by these sources of light. In our work, conjugated polymers with different emission colors have successfully been obtained. In particular, several single white emitters have been isolated.In this PhD thesis, not only the synthetic procedures and chemical characterizations are presented in detail, but also the studies of the photophysical properties of the polymers, either in solution or in the solid state. Solid state studies were performed on the bulk polymers and on the polymers dispersed into a polymeric matrix. These studies have lead to identify the limiting factors that could hamper the use of the materials. Solutions have been proposed to improve the materials performance and stability. Furthermore, 2,2’-bipyrimidine has been introduced as a new synthon for designing and developing conjugated polymers.

The circular economy is promoted by the EU, governments, and businesses all over the world as a concept to reach a sustainable future. The concept is embedded into the UN Sustainable Development Goals for 2030 and aims to decouple economic growth and environmental pressure. Many studies have been conducted on the circular economy in recent years but the research on the actual environmental performance of the concept is limited. To move forward with the concept of the circular economy and reach a sustainable future, the environmental performance must be investigated. In this thesis, the environmental impact of circularity in products is investigated by comparing the environmental impact from one circular and one linear product case. To achieve this, the environmental impact and the degree of circularity is calculated with two different methods. The circularity is calculated with a circularity indicator called the Linear Flow Ratio and the environmental impact is assessed with the environmental evaluation technique Life Cycle Assessment (LCA). In the LCAs, the cases are compared for different environmental impact categories (e.g. global warming). The product that is investigated is an LED lighting fixture from the company 2P1. The circular case is based on a leasing business model and includes remanufacturing, reuse and recycling. The linear case includes production, sales, use, and disposal. The LCA results show that the environmental impact from the circular case is lower for all environmental impact categories. The environmental impact is almost exclusively from the manufacturing phase (including extraction and production of raw materials) and the use phase. The circularity results from the Linear Flow Ratio show contradicting results, presenting that the degree of circularity is higher for the linear case. By comparing the results to calculations from another circularity indicator (Material Circularity Indicator), it is concluded that a unified framework for circularity measurements is required. / Cirkulär ekonomi är introducerat av EU, länder och företag över hela världen som ett koncept för att nå en hållbar framtid. Den cirkulära ekonomin är en del av arbetet mot agenda 2030 för hållbar utveckling och strävar efter att frånkoppla ekonomisk tillväxt från miljöpåverkan. Det har forskats mycket på cirkulär ekonomi under de senaste åren men studier som undersöker det miljömässiga utförandet av konceptet saknas. För att fortsätta att utveckla konceptet och för att nå en hållbar framtid så måste den miljömässiga påverkan från cirkularitet undersökas. I denna studie undersöks miljöpåverkan från cirkularitet hos produkter genom att jämföra miljöpåverkan från ett cirkulärt och ett linjärt fall. Miljöpåverkan och cirkularitetsgraden beräknas med två olika metoder. Cirkulariteten beräknas med cirkularitetsindikatorn Linear Flow Ratio och miljöpåverkan analyseras men livscykelanalys. I livscykelanalyserna värderas miljöpåverkan för de två fallen för olika påverkanskategorier (t.ex. global uppvärmning). Produkten som undersökt är en LED-armatur från företaget 2P1. Det cirkulära fallet basers på uthyrning av armaturerna och innehåller renovering, återanvändning och återvinning. Det linjära fallet innehåller produktion, försäljning, användning och bortskaffande av produkten. Resultaten från livscykelanalyserna visar att det cirkulära fallet medför mindre miljöpåverkan för alla kategorier. Miljöpåverkan kommer nästan enbart från produktion (inklusive material) samt användning. Cirkularitetsresultaten från Linear Flow Ratio visar motsägelsefulla resultat då det linjära fallet har en högre cirkularitetsgrad än det cirkulära fallet. Genom att jämföra resultaten med beräkningar från en annan cirkularitetsindikator (Material Circularity Indicator) kan det fastställas att ett enhetligt ramverk för beräkning av cirkularitet är nödvändigt framöver.

Le travail de cette thèse a été consacré au développement d’une nouvelle méthode de détection pour un système anticollision par la mesure de trajectographie, ce qui pourrait contribuer aux systèmes d’aide à la conduite. Pour obtenir une haute probabilité de détection, nous avons choisi la solution de vidéo stéréoscopique coopérative : la coopération entre véhicules rend la détection plus facile et fiable. Il y a deux participants dans le système : les véhicules « porteurs du système » aussi bien que les « suiveurs », sont équipés de caméras stéréoscopiques, c’est à dire de deux capteurs d’image, appartenant à des familles technologique à haute cadence; les véhicules « cibles » sont équipés des feux à Leds modulés, dont la fréquence de modulation est déjà connue par les véhicules « suiveurs ». Après filtrage dans l’espace temporel, le système ne détecte que des signaux issus des feux modulés, ce qui réduit fortement l’information à traiter par rapport aux calculs de trajectographie traditionnels. La détection de feux modulés est donc réalisée par le filtrage par traitement numérique des images, qui est adapté à la fréquence de modulation recherchée. Pour cela, nous avons proposé 3 types de filtres adaptés à la fréquence de modulation et conçus de façon à rejeter au mieux les signaux de fond.Pour évaluer les performances tant en détection qu’en réjection des fausses alarmes, nous avons d’abord effectué des simulations numériques en prenant en compte des signaux artificiels, puis des calculs sur vrais signaux obtenus dans les expérimentations avec véhicule d’essai statique, puis roulant. Les roulages étaient de différentes vitesses, de 30km/h jusqu’à 100km/h, ce qui nous a permis d’analyser le signal issu du feu ainsi que le comportement de nos filtres à des vitesses angulaires de feu nulles, faibles ou élevées. Le résultat de ces expérimentations montre que le filtrage permet de détecter les feux à Leds de type DRL jusqu’à 140m sans aucune fausse détection sur le fond. Ces expérimentations sont une étape essentielle pour définir de façon plus précise un tel système, en particulier dans le choix du seuil. Nous avons aussi évalué des technologies qui peuvent améliorer la performance du système, mais qui ne sont pas encore prêtes à industrialiser. Par exemple, les « rétines » artificielles nous permettent d’utiliser les filtres analogiques intégrés, et ainsi de réduire leurs bandes passantes. / This thesis was devoted to the development of a new detection method for vehicular collision avoidance system based on trajectory measurement, which could contribute to driver assistance systems.In order to obtain high detection probability, we have chosen the cooperative stereoscopic video solution: the cooperation between vehicles makes it easier and more reliable when they aim to detect each other. There are two participants in the system: the “system carriers" vehicles, or the " followers" are equipped with stereoscopic cameras (two image sensors), who belong to high speed technology families; the "targets" vehicles are equipped with modulated LED lights, with the modulation frequency being already known by the "followers". After space-time filtering, the system detects the signals emitted bymodulated lights sources, which greatly reduces the amount of information to be processed comparing to traditional trajectory calculations methods. The detection of modulated light is achieved by filtering based on digital image processing, which is adapted to the desired modulation frequency. We have proposed three types of filters suitable for detecting the modulation at this frequency and at the same time for rejecting the background as well as possible.In order to be able to evaluate the performances of both detecting signals and rejecting false alarms, we first performed numerical simulations based on the model signals, then calculations on real signals acquired in static and driving experiments. The tested speeds were from 30km/h up to 100km/h, which allowed us to analyze the signals emitted from vehicle lights as well as the behavior of our filters under different angular velocities of the lights (zero, low and high). The result of these experiments showed that our method of filtering could detect LED-type DRL lights up to 140m without any false alarm. This is essential to define more precisely the values of thresholds of such systems. We have also evaluated technologies that are possible to improve system performance in the future, which are not yet ready to be used in industry productions. For example, artificial "retinas" could allow us to integrate analog filters in the chips, and thus to reduce bandwidth of the filters.