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Elanvändningen till ventilation har ökat med 40 % sedan 1990 i Sverige. Ventilationen är en miljöbov enligt undersökningar som visar att elanvändningen till ventilationssystemens fläktar kan reduceras. Minskning av elförbrukningen kan t.ex. uppnås genom utbyte av fläktmotor till en EC-motor eller till en fläkt med bakåtböjda skovlar och direktdrift. Effektivieringsåtgärder kan ge en lägre elförbrukning på upptill 50 % i vissa applikationer. Ventilationsfläktarna i Sverige förbrukar 12,3 TWh per år. Idag har 175 000 ventilationsaggregat en för hög elanvändning och saknar värmeåtervinning. Enligt Energimyndigheten har området ventilation en stor besparingspotential eftersom energianvändningen till ventilation kan minska med 30 % (3,5 TWh), vilket ungefär motsvarar vindkraftsproduktionen i Sverige under ett år. Det analysverktyg som utvecklats i detta examensarbete är användarvänligt utformat och är tänkt som ett hjälpmedel vid utvärdering av funktion och effektivitet i luftbehandlingssystem. Verktyget analyserar mätdata från luftbehandlingssystemet och producerar nyckeltal som sedan jämförs mot givna nyckeltal och riktvärden, samt myndigheters gällande krav. Analysverktyget har provats på ett referensobjekt och fungerade som tänkt men får, i nuvarande utformning, anses vara en prototyp som kan vidareutvecklas. Viss utbildning krävs innan användning av analysverktyget sker, med hänsyn till elsäkerhet och mätnoggrannhet. Detta examensarbete avser vidare att kartlägga hur stor besparingspotential det finns för energieffektivisering av byggnaders ventilation samt att utveckla ett beräkningsverktyg för att kunna möta efterfrågan som troligtvis kommer att uppstå från fastighetsägare som vill spara energi. / Electricity consumption for ventilation has increased by 40% since 1990 in Sweden. Ventilation is an environmental villain since inquiries indicates that the electricity consumption for ventilation system fans can be much reduced. Reduction of electricity consumption for ventilation purposes can be achieved through e.g. the exchange of fan motors to EC motors or to fans with backward curved blades and direct drive. Such measures can provide reduced power consumption by up to 50 % in some applications. The ventilation fans in Sweden consume 12.3 TWh each year. Today Sweden has 175 000 ventilation systems with too high consumption of electricity and no heat recycling. According to the Swedish Energy Agency the ventilation sector has a large potential for savings and the energy consumption for ventilation could be lowered by 30 % (3,5 TWh), which roughly corresponds to the total annual wind power production in Sweden. The Analytical tool developed in this thesis work is designed to be user friendly and is thought to be an aid when evaluating functionality and efficiency in air treatment system. The tool analyzes data from measurements and produces key ratios which are then compared with given key ratios and standard guidelines. The Analysis tool was tested on one reference object and functioned as intended, but may at this stage be considered as a prototype that can be further developed. Specific training will be required before using the analysis tool with consideration to electrical safety and accuracy of measurement. This thesis work aims at evaluating the potential savings within air treatment systems in energy efficient buildings, and to develop a calculation tool to meet the demand that is likely to arise from property owners who want to save energy.

Microbial pathogens commonly transmitted through the aerosol route to surfaces, equipment, and hands in the clinical setting leads to costly and life threatening hospital-acquired infections (HAIs). Even with improved hand hygiene and surface disinfection, HAIs continue to persist in healthcare environments, warranting consideration of novel interventions to reduce the transmission risk of HAIs. This study quantitated the efficacy of ion generating passive air treatment (PAT) against viruses (MS2), bacteria (Escherichia coli), and bacterial spores (Bacillus thuringiensis) in a controlled environmental setting. Microorganisms were seeded into a 2.72 m3 chamber using a positive pressure nebulizing device to generate aerosolized droplets. The PAT unit was then turned on and seeded organisms were collected at various time points using impingers to concentrate the organisms into sterile aqueous solution. The microorganisms were enumerated using approved standard protocols developed in the Environment, Exposure Science, and Risk Assessment Center's laboratory at The University of Arizona. Three experiments were conducted to challenge the PAT unit. Experiment one evaluated the efficacy of the PAT unit over a single 10-minute period on microbial inactivation from the airborne environment following a single seeding; additionally, experiment one aimed to determine the efficacy of the PAT unit against viruses, bacteria, and bacterial spores on environmental surfaces; experiment two evaluated the efficacy of the PAT unit running continuously over a period of 6 hours following a single seeding; and experiment three evaluated the efficacy of the PAT unit running two continuously over a period of 5.25 hours following two seeding events. Bacterial spores from pre- and post-treatment with the PAT unit were collected and analyzed by scanning electron microscopy to assess structural differences. After a single seeding and 10 minutes of continuous treatment of the PAT unit, normalized average microbial log10 reductions of post-treatment compared to pre-treatment air concentrations were 1.67, 0.59, and 1.04 for MS2, B. thuringiensis spores, and E. coli, respectively. Differences in average log10 reductions between the control unit and the PAT unit were statistically significant for MS2 (p=0.009) and B. thuringiensis (p=0.0455), but not for E. coli (p=0.0565). The geometric mean log10 surface concentrations of MS2, B. thuringiensis, and E. coli after a single seeding and 10 minutes of continuous treatment of the PAT unit were 7.30 PFU/100 cm2, 5.90 CFU/100 cm2, and 2.74 CFU/100 cm2, respectively, compared to exposure of the control unit, 8.59 PFU/100 cm2, 6.03 CFU/100 cm2, and 4.96 CFU/100 cm2, respectively. There was a statistically significant difference between the mean log10 surface concentrations following 10 minutes of treatment with the control unit compared to the PAT unit for E. coli (p=0.002), but not for MS2 (p=0.3358) or B. thuringiensis (p=0.0866). After a single seeding and 6-hours of continuous treatment of the PAT unit, normalized average microbial log10 reductions of MS2 and B. thuringiensis were 1.43 and 1.32, respectively. The difference in average log10 reduction of all post-treatment samples between the control unit and the PAT unit was statistically significant for B. thuringiensis (p=0.0008) but not for MS2 (p=0.2568). After two seedings and 5.25 hours of continuous treatment of the PAT unit, normalized average microbial log10 reductions of MS2 and B. thuringiensis were 1.59 and 1.26, respectively. There was a statistically significant difference in the average log10 reductions between the control unit and the PAT unit for MS2 (p=0.002) and B. thuringiensis (p=0.0003). Scanning electron microscopy analysis identified visual modification to B. thuringiensis spores following treatment with the PAT unit. In this study, the tested ion generating PAT unit was effectively able to reduce airborne microbial concentrations between 1-2 log10 in a controlled chamber environment within 10 minutes and up to 6 hours of treatment. The implications of this study suggest that ion producing PAT systems may represent a beneficial supplement to cleaning and disinfection practices in the reduction of pathogen contamination from the airborne and fomite-airborne routes.

L’objectif principal de ce travail a été d’étudier le potentiel de mousses alvéolaires tridimensionnelles en carbure de silicium de forme béta (β-SiC) comme support de photocatalyseur, dans le but de mettre au point des réacteurs photocatalytiques structurés pour le traitement de l’air. Ces mousses alvéolaires de β-SiC de surface spécifique moyenne et de porosité très ouverte sont obtenues par la synthèse dite à mémoire de forme (Shape Memory Synthesis), consistant en la carburation contrôlée d’une mousse alvéolaire de polyuréthane préformée. Une étude de la dégradation de trois polluants sur des films minces en mode de lit léchant (la méthyléthylcétone, l’ammoniac et le sulfure d’hydrogène) a tout d’abord permis de sélectionner trois photocatalyseurs d’intérêt parmi six références commerciales avant d’être immobilisés sur les mousses de β-SiC. Après une étape d’optimisation en termes de taille d’alvéoles, de nature et quantité de photocatalyseur, le média photocatalytique TiO2/mousses de β-SiC a été caractérisé et ses performances comparées en mode mono-passage ainsi qu’en mode de recirculation du flux dans une enceinte de 2 m3, à celles d’un film mince de TiO2 et d’un média photocatalytique commercial de référence. Le média photocatalytique TiO2/mousses de β-SiC présente des performances nettement améliorées par rapport à celles du média référent. Les mousses jouent un rôle de mélangeur statique et permettent une meilleure utilisation du volume du réacteur, en augmentation la densité de photocatalyseur par unité de volume tout en maintenant une illumination du cœur du réacteur acceptable ainsi que des pertes de charge très limitées. / The main objective of this work was to study the potential of three-dimension beta silicon carbide (β-SiC) alveolar foams for use as photocatalyst support, targeting the implementation of structured photocatalytic reactors for air treatment. Medium surface area β-SiC alveolar foams were synthesized according to the Shape Memory Synthesis concept, consisting in the controlled carburization of a preshaped polyurethane foam. First, the degradation of three model pollutants (methylethylketone, ammonia and hydrogen sulfide) was performed over TiO2 thin layers in a flow-through reactor for selecting three photocatalysts of interest – Hombikat UV100, PC500 and P25 TiO2 – among six commercial standards. The powderly photocatalysts were further immobilized onto β-SiC foams. After an optimization step in terms of mean cell size, light transmission, photocatalyst nature and weight content as well as of the immobilization method, the TiO2/β-SiC foam photocatalytic media was characterized and its photocatalytic behaviour was compared in a single-pass mode as well as in a recirulation mode inside a 2 m3 chamber, to those obtained on a TiO2 thin layer and with a well-known commercial photocatalytic felt media made from quartz fibers supporting sol-gel TiO2. The photocatalytic media elaborated with β-SiC alveolar foams exhibited superior performances compared to that of the commercial felt standard. The foams acted as static mixing within the reactor and allowed a more efficient use of the reactor volume, by increasing the photocatalyst density per reactor volume unit, while maintaining however a suitable illumination within the reactor core as well as very low pressure drops.

The development of ideas on deinstitutionalization of mental patients has a much longer history in the United States than is commonly acknowledged. Evidence of intense discussion on the rights of the mentally disturbed, curative as opposed to control measures in their treatment, and the drawbacks of congregating the afflicted in large institutions can be found as early as the middle of the 19th century. This discussion was provoked by dissemination of knowledge about the oldest community care program of all: the colony of mental patients in Gheel, Belgium. Based on document analysis of publications in the American Journal of Insanity from 1844 to 1921, this study attempts to trace how this discussion resulted in the first wave of deinstitutionalization in the American mental health care system, and the successful implementation of the alternative of hospital treatment. My study further documents how the development of this program was inhibited by the need of psychiatry to attain professional legitimation. In its struggle to acquire public respect and occupational authority, the profession focused on somatic explanations of disease that could justify categorization of psychiatry as a branch of medical science. While this claim was not decisively supported by laboratory findings, or the ability to cure patients, psychiatry put forward genetic explanations of mental disorder. This took the profession to the extreme of the eugenics movement, and eventually positioned it as an institution of social control instead of medical authority. Having thus failed to achieve the ultimate professional legitimation in the medical field, psychiatry was exposed to a new wave of criticism in the 1960s, which led to the second wave of deinstitutionalization. History repeated itself with the same outcome. In the absence of overall support within psychiatric circles, and a lack of appreciation of family care as a viable alternative to hospital treatment among social scientists, deinstitutionalization could not but fail again. The contribution of the study lies in the areas of deinstitutionalization, professionalization of expert labor, and the social construction of mental illness and deviance.

<p> </p> <p>ndoor air quality (IAQ) due to the presence of airborne microorganisms or bioaerosols (0.01-10 μm) in indoor spaces has been a concern for many years; however, it gained significant attention during the COVID-19 pandemic. Photocatalytic oxidation (PCO) has shown promising potential to kill microorganisms (removal/disinfection) and has already been in use within HVAC systems to treat volatile organic compounds (VOCs) (treatment). The main motivation of this work is to understand whether PCO devices can be used for bioaerosol removal in indoor spaces by integrating them with HVAC systems. Among the various factors that influence the adoption of PCO for large-scale bioaerosol removal, this work specifically tries to investigate two factors 1) whether the commercially available PCO reactors for treatment can be used for removal/disinfection or not, and 2) how to setup a standardized experimental setup for evaluating the removal efficiency of these systems. Generally, most of the commercial PCO devices use UV- based photocatalysis, so the removal efficiency is a combination of inactivation by UV and the reactive oxygen species produced by photocatalytic reactions (pure photocatalytic effect).</p> <p>In this work, the bioaerosol transport and the photon transport in a reactor is hypothesized as central to using the photocatalytic effect to inactivate microorganisms. This study uses analytical models to estimate the collection efficiency of the bioaerosols inside the honeycomb channels as a function of non-dimensional aspect ratios and velocity typical of HVAC systems. Subsequently, the collection efficiency results are overlaid with the prior literature results on photon transport inside such channels to present a limiting case for the removal efficiency of these systems. Another crucial factor for the performance of PCO systems is to investigate about the bioaerosol remediation on a photocatalyst substrate. Since there are many challenges associated with the numerical modeling of this phenomenon, this work developed a standardized experimental setup at the Herrick Laboratories, Purdue to investigate these interactions and further validate the previous hypothesis .The setup is constructed to systematically characterize the bioaerosol flowing through the airstream and measure data crucial to the PCO reactor performance, such as fluence rate field, number concentration (#/cm3), and viable concentration (CFU or PFU/m3) of the microorganisms upstream and downstream of the treatment sections. </p> <p>The collection efficiency (CE) of bioaerosols in honeycomb channels with velocities typical to HVAC systems were estimated using analytical models, and the results were presented in dimensionless aspect ratios (AR= Lch/ Dch). Based on the CE modeling results, the highest CE for aspect ratio 25 was less than 20% for the entire bioaerosol size range. From the prior literature results on photon transport, it was found that the intensity of the light reduced significantly for aspect ratios less than or equal to 6. Based on these results, it was found that the existing honeycomb geometries weren’t effective for PCO disinfection in operating conditions typical of HVAC systems. Since there aren’t any existing well-established methods to experimentally investigate these kinds of systems, this work will present the details about the development of the proposed methods inspired from prior literature for general air cleaning devices and small-scale PCO experiments. Furthermore, a detailed discussion about the important subsystems such as aerosol generation subsystem, sampling subsystem, and reactor subsystem which is crucial to investigating the hypotheses is presented in this thesis. Finally, some preliminary results on each of these characterization experiments to test the hypotheses has been presented in this thesis.</p>

Ce projet de thèse s'inscrit dans la recherche et le développement de dispositifs de lutte contre les émissions de composés organiques volatils (Programme principal n°7). En effet, l'objet de ce projet est d'étudier et de développer une nouvelle génération de microréacteurs catalytiques structurés pour la dépollution d'effluents gazeux contenant des composés organiques volatils (COV) issus de sources dispersées et/ou confinées. La difficulté principale du traitement des effluents gazeux est souvent liée à la multiplicité des sources de pollution et donc à la nécessité de collecter tous les effluents pollués vers une unité de traitement de grande échelle. Tout procédé qui pourrait facilement s'adapter et répondre à des pollutions diverses et localisées quels que soient les polluants, le débit et l'application, constituerait une grande avancée technologique dans le traitement de la pollution de l'air. Ainsi, des microsystèmes catalytiques pourraient être mis en oeuvre pour le traitement de composés organiques volatils dans des environnements industriels divers comme des ateliers d'imprimerie, de séchage, de peinture, de vernissage et des ateliers de nettoyage à sec. Toutes ces applications présentent un intérêt majeur d'un point de vue environnemental et de santé publique et constituent des cas idéaux pour mettre en oeuvre ces nouveaux microsystèmes et démontrer leur efficacité. Les microréacteurs présentent un avantage certain en terme de conception de procédés. La possibilité d'associer des éléments microstructurés ou des petites unités permet d'adapter et d'intégrer le procédé catalytique de façon appropriée, indépendamment de l'échelle et l'effluent. De plus, le concept modulaire est évidemment plus sûr. Ainsi, les microréacteurs construits à partir de plaques microstructurées permettent une distribution du flux gazeux dans l'ensemble des microcanaux. En outre, en raison des dimensions caractéristiques des microcanaux, les dispositifs microstructurés permettent une grande diminution de la distance entre la zone catalytique et le fluide conduisant à de meilleures propriétés de transferts que les réacteurs à lit fixe. Enfin et surtout, les microréacteurs catalytiques permettent une manipulation plus sûre des produits dangereux, inflammables et même explosifs que dans les réacteurs conventionnels. En partenariat avec le Laboratoire d'Analyse et d'Architecture des Systèmes (LAAS-Toulouse), ce projet vise donc à concevoir et à développer des réacteurs catalytiques microstructurés suivant les objectifs définis précédemment. Ces microréacteurs sont constitués d'un empilement de plaques de silicium recouvertes d'une couche fine de platine utilisant des technologies de la microélectronique. Les technologies utilisées par le LAAS constituent une alternative aux dépôts catalytiques sur des microstructures existantes. De plus, un des avantages majeurs de l'utilisation des microtechnologies est la possibilité d'intégrer les sources chauffantes sur une plaque de silicium (résistances thermiques métalliques). Ainsi, l'intégration de sources chauffantes au coeur du microréacteur est une solution intéressante à la question des besoins énergétiques. Les travaux associés à ce projet de thèse visent à optimiser les performances et les conditions de fonctionnement de microréacteurs catalytiques et à mieux comprendre et appréhender les phénomènes impliqués. Les performances des microréacteurs conçus sont évaluées vis-à-vis de diverses molécules représentatives des émissions industrielles aux mélanges de COV avec pour objectif final une étude sur des effluents réels. / This thesis project is part of the research and development of devices to fight against the emission of volatile organics compounds.

La photocatalyse hétérogène est une technique d’oxydation utilisée pour l’élimination des Composés Organiques Volatils (COV). L’objectif est d’étudier la dégradation des COV initiaux et la production d’intermédiaires réactionnels lors de la mise en oeuvre de ce procédé dans des conditions proches de l’air intérieur (concentration des COV en mélange). TroisCOV modèles (toluène, décane, trichloréthylène) sont étudiés séparément puis en mélange dans un réacteurstatique puis dans un réacteur dynamique multi-pass. Les résultats obtenus montrent que (i) l’efficacité dedégradation dépend de la nature et du nombre de COV à traiter, des caractéristiques du média photocatalytiqueet des conditions opératoires, (ii) les intermédiaires majoritaires et les plus persistants sont les aldéhydeslégers, (iii) l’élimination des aldéhydes est inhibée lorsque les COV initiaux sont en mélange, (iv) l’augmentation du temps de résidence sur le matériau photocatalytique permet une élimination plus rapide des COV initiaux et des sous-produits. / Heterogeneous photocatalysis is a technique of oxidation used for the removal of Volatile Organic Compounds (VOCs). Aim is to study the degradation of initial VOCs and the production of reaction intermediates during this process in conditions close to the indoor air (VOC concentration in mixture). Three model VOCs (toluene, decane, trichloroethylene) are studied separately and then in mixture in a static reactor and in a dynamic multi-pass reactor. The obtained results show that (i) the degradation efficiency depends on the nature and the number of VOCs, on the photocatalyst characteristics and on process conditions, (ii) the major and the most persistent intermediates are light aldehydes, (iii) the elimination of aldehydes is inhibited when the initial VOCs are in mixture, (iv) increasing the residence time on the photocatalyst provides a higher removal rate of initial VOCs and of byproducts.

Title from PDF of title page. / Document formatted into pages; contains 60 pages. / Thesis (M.A.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The development of ideas on deinstitutionalization of mental patients has a much longer history in the United States than is commonly acknowledged. Evidence of intense discussion on the rights of the mentally disturbed, curative as opposed to control measures in their treatment, and the drawbacks of congregating the afflicted in large institutions can be found as early as the middle of the 19th century. This discussion was provoked by dissemination of knowledge about the oldest community care program of all: the colony of mental patients in Gheel, Belgium. Based on document analysis of publications in the American Journal of Insanity from 1844 to 1921, this study attempts to trace how this discussion resulted in the first wave of deinstitutionalization in the American mental health care system, and the successful implementation of the alternative of hospital treatment. / ABSTRACT: My study further documents how the development of this program was inhibited by the need of psychiatry to attain professional legitimation. In its struggle to acquire public respect and occupational authority, the profession focused on somatic explanations of disease that could justify categorization of psychiatry as a branch of medical science. While this claim was not decisively supported by laboratory findings, or the ability to cure patients, psychiatry put forward genetic explanations of mental disorder. This took the profession to the extreme of the eugenics movement, and eventually positioned it as an institution of social control instead of medical authority. Having thus failed to achieve the ultimate professional legitimation in the medical field, psychiatry was exposed to a new wave of criticism in the 1960s, which led to the second wave of deinstitutionalization. History repeated itself with the same outcome. / ABSTRACT: In the absence of overall support within psychiatric circles, and a lack of appreciation of family care as a viable alternative to hospital treatment among social scientists, deinstitutionalization could not but fail again. The contribution of the study lies in the areas of deinstitutionalization, professionalization of expert labor, and the social construction of mental illness and deviance. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

This thesis discusses the development of an improved microbial inactivation model for analyzing continuous flow UV-LED air treatment systems and use of the model to evaluate the impact of several treatment system design parameters on inactivation. Model development includes three submodels: a radiation submodel, a fluid flow submodel, and an inactivation kinetics submodel. Radiation modeling defines the UV irradiance throughout the system. Fluid flow modeling provides the residence times that microbes spend exposed to the UV irradiation while passing through the system. Inactivation modeling combines irradiance and residence times with inactivation kinetics to calculate species-specific inactivation in a treatment system. The most significant development focuses on the radiation submodel as it is key to linking the UV intensity emissions to treatment system properties and inactivation rates. Various radiation transfer models previously developed by other researchers are evaluated for computational efficiency and effectiveness in modeling non-uniform LED emission and diffuse and specular wall reflections. The Discrete Ordinates Method (DOM) with Legendre-Chebyshev quadrature sets is selected for use in this research due to its ability to represent both non-uniform LED emission profiles and combined specular and diffuse surface reflection. The DOM and associated quadrature schemes are reviewed in detail and limitations in representing LED emissions discussed. Sensitivity to spatial and directional discretization is evaluated. The radiation submodel is combined with a well-accepted inactivation kinetics correlation and two simple fluid flow models: a uniform flow model and a fully-developed flow model. The use and validity of these submodels is explained and their limitations discussed. Predicted microbial inactivation from the overall model is shown to compare well with limited data from a test system. Model flexibility in evaluating several system operating and design parameters is illustrated. These analyses show that for a similar number of LEDs, highly reflective surfaces (diffuse or specular) produce higher inactivation. Other parameters are shown to impact inactivation but to a lesser degree. Square ducts result in higher inactivation than non-square ducts, a fully-developed flow profile slightly increases inactivation over a uniform flow profile, positioning LEDs on all four duct walls slightly increases inactivation when surfaces are non-reflective or diffuse, and positioning LEDs closer together results in slightly higher inactivation.