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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
271

Occupants' quality of life experience with sustainable work environments : using a mixed-methods approach to develop a humane and sustainable framework for assessing the indoor environmental quality in office buildings

Wifi, Mariam 11 1900 (has links)
Cette recherche étudie la perception de la qualité de vie (QV) et de la qualité de l'environnement intérieur (QEI) du point de vue des occupants d’espaces de travail certifiés « durables » selon le système d'énergie et de conception environnementale (LEED) et des occupants des immeubles de bureaux conventionnels. Dans cette étude, la QV est définie en termes de santé perçue, confort, et productivité. La qualité des environnements intérieurs est importante, car les gens passent la majorité de leur vie à l'intérieur des immeubles et, dans notre société contemporaine, plus de ce temps est passé dans des espaces de travail, tels que les espaces de bureaux. Les préoccupations grandissantes pour la durabilité des espaces de vie et la prise de conscience des effets négatifs que des bâtiments peuvent avoir sur les occupants font émerger les constructions dites ‘vertes’ comme étant des alternatives plus durables. LEED est le système d’accréditation le plus populaire de nos jours en Amérique du Nord qui évalue les bâtiments verts en terme de leur performance environnementale. Toutefois, la revue de littérature indique que des occupants des édifices de bureaux certifiés LEED ne sont pas toujours satisfaits avec la QEI. Les bâtiments certifiés LEED sont en effet uniquement évalués selon des critères techniques de performance. Pourtant, il y peut avoir des écarts entre les performances mesurées et celles perçues par les occupants. Cela soulève la question suivante: à quel point les bâtiments construits selon les critères LEED prennent-ils en compte la qualité de vie (QoL) et les facteurs humains dans l’évaluation des espaces de travail ? Cette recherche a donc pour but de proposer un nouveau cadre qui prend en considération non seulement des facteurs durables, mais aussi humains pour évaluer les environnements de travail. Cette recherche utilise une approche mixte – quantitative et qualitative – en trois phases afin d’étudier de manière approfondie la perception de la qualité de vie des occupants de deux bâtiments certifiés LEED et d’un immeuble de bureaux conventionnel. La phase I est dédiée à l’observation des environnements de travail et la documentation des traces d’interaction entre l’utilisateur et l’espace. La phase II est dédiée aux entrevues permettant aux participants de décrire leur expérience de la QV et les facteurs de la QEI qui façonnent leur expérience. Ils nous aident aussi à identifier les éléments constitutifs d'un environnement humain de travail. Parallèlement, des questionnaires aident à comprendre la relation entre la qualité de vie perçue par les occupants et les facteurs de QEI dérivés de la littérature. À l’aide de groupes de discussion, menés lors de la phase III, nous cherchons à valider les résultats préliminaires. Les données sont ensuite analysées séparément en utilisant la ‘triangulation’ afin d’interpréter et corroborer les résultats. Cette étude compare les expériences des espaces de travail « verts » et « conventionnels » et révèle 32 facteurs (30 facteurs QEI et deux autres) qui peuvent affecter de manière significative l'expérience des édifices de bureaux. De plus, des éléments constitutifs d'un environnement de travail humain du point de vue des occupants ont été identifiés. Ceux-ci nous permettent donc de mettre au point un nouveau cadre global, intégrant des critères humains pour évaluer la QEI dans des environnements de travail durables. Ce cadre met en relation la QEI des environnements de travail et la QV des occupants en tant que système environnement-comportement. / This research studies perceived Quality of Life (QoL) and Indoor Environmental Quality (IEQ) of occupants’ in the work environments of sustainable office buildings certified under the Leadership in Energy and Environmental Design (LEED) system (green buildings) and in conventional office buildings. QoL is defined in this research in terms of perceived health, comfort, and productivity. The quality of indoor environments is important because people spend most of their time inside buildings, and in contemporary society, much of the time spent in work environments is in office buildings. In this era of growing concerns about sustainability and the increased awareness of buildings’ negative impacts on occupants, green buildings have been promoted as sustainable solutions to these issues. LEED is the most popular rating system for measuring the performance of green buildings in North America. However, the literature review indicates that there are user complaints about the IEQ of LEED-certified office buildings. LEED-certified buildings are assessed based on technical measures of building performance. This assessment way may create a gap between measured and perceived performance from the user perspective. This raises the question of whether buildings certified with the LEED criteria are humane from the QoL experience of occupants in office buildings. Hence, this research is therefore to propose a new framework that takes into account not only sustainable but also humane factors for evaluating work environments. The study uses a mixed-methods approach – using both quantitative and qualitative methods and proceeds in three phases to comprehensively study occupants’ perceived QoL experience in two LEED and one conventional office building. Phase I uses observations to document the physical work environment and users’ behavioral interactions with the environment. Phase II uses interviews to describe the occupants’ QoL experience, explore the possible IEQ factors shaping their QoL, and to define the constructs of a humane work environment. Questionnaires were distributed concurrently to measure the relationship between occupants’ perceived QoL and IEQ factors that are derived from the literature. Phase III uses focus groups to converge and focus the results of the study. The results are analyzed separately and triangulated using an integrative mixed-methods analysis to interpret, corroborate, conclude, and increase the validation of the findings. The study compared occupants’ perceived QoL in «green» and «conventional» office buildings and revealed 32 quality factors (30 IEQ factors and two others) that influence the QoL experience in office work environments. Also the constructs of what composes a humane work environment based on occupants’ viewpoints have been identified. A new comprehensive, sustainable, and humane framework for assessing IEQ in work environments is developed. This framework guides the relationship between IEQ in work environments and occupants’ QoL as an environment-behavior system.
272

Electronic Coupling Effects and Charge Transfer between Organic Molecules and Metal Surfaces / Elektronische Kopplungseffekte und Ladungstransfer zwischen organischen Molekülen und Metalloberflächen

Forker, Roman 28 January 2010 (has links) (PDF)
We employ a variant of optical absorption spectroscopy, namely in situ differential reflectance spectroscopy (DRS), for an analysis of the structure-properties relations of thin epitaxial organic films. Clear correlations between the spectra and the differently intense coupling to the respective substrates are found. While rather broad and almost structureless spectra are obtained for a quaterrylene (QT) monolayer on Au(111), the spectral shape resembles that of isolated molecules when QT is grown on graphite. We even achieve an efficient electronic decoupling from the subjacent Au(111) by inserting an atomically thin organic spacer layer consisting of hexa-peri-hexabenzocoronene (HBC) with a noticeably dissimilar electronic behavior. These observations are further consolidated by a systematic variation of the metal substrate (Au, Ag, and Al), ranging from inert to rather reactive. For this purpose, 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) is chosen to ensure comparability of the molecular film structures on the different metals, and also because its electronic alignment on various metal surfaces has previously been studied with great intensity. We present evidence for ionized PTCDA at several interfaces and propose the charge transfer to be related to the electronic level alignment governed by interface dipole formation on the respective metals. / Zur Analyse der Struktur-Eigenschafts-Beziehungen dünner, epitaktischer Molekülfilme wird in situ differentielle Reflexionsspektroskopie (DRS) als Variante der optischen Absorptionsspektroskopie verwendet. Klare Zusammenhänge zwischen den Spektren und der unterschiedlich starken Kopplung zum jeweiligen Substrat werden gefunden. Während man breite und beinahe unstrukturierte Spektren für eine Quaterrylen (QT) Monolage auf Au(111) erhält, ist die spektrale Form von auf Graphit abgeschiedenem QT ähnlich der isolierter Moleküle. Durch Einfügen einer atomar dünnen organischen Zwischenschicht bestehend aus Hexa-peri-hexabenzocoronen (HBC) mit einem deutlich unterschiedlichen elektronischen Verhalten gelingt sogar eine effiziente elektronische Entkopplung vom darunter liegenden Au(111). Diese Ergebnisse werden durch systematische Variation der Metallsubstrate (Au, Ag und Al), welche von inert bis sehr reaktiv reichen, untermauert. Zu diesem Zweck wird 3,4,9,10-Perylentetracarbonsäuredianhydrid (PTCDA) gewählt, um Vergleichbarkeit der molekularen Filmstrukturen zu gewährleisten, und weil dessen elektronische Anordnung auf verschiedenen Metalloberflächen bereits eingehend untersucht worden ist. Wir weisen ionisiertes PTCDA an einigen dieser Grenzflächen nach und schlagen vor, dass der Ladungsübergang mit der elektronischen Niveauanpassung zusammenhängt, welche mit der Ausbildung von Grenzflächendipolen auf den entsprechenden Metallen einhergeht.
273

Design thinking and the precautionary principle : development of a theoretical model complementing preventive judgment for design for sustainability enriched through a study of architectural competitions adopting LEED

Cucuzzella, Carmela 03 1900 (has links)
Cette thèse contribue à une théorie générale de la conception du projet. S’inscrivant dans une demande marquée par les enjeux du développement durable, l’objectif principal de cette recherche est la contribution d’un modèle théorique de la conception permettant de mieux situer l’utilisation des outils et des normes d’évaluation de la durabilité d’un projet. Les principes fondamentaux de ces instruments normatifs sont analysés selon quatre dimensions : ontologique, méthodologique, épistémologique et téléologique. Les indicateurs de certains effets contre-productifs reliés, en particulier, à la mise en compte de ces normes confirment la nécessité d’une théorie du jugement qualitatif. Notre hypothèse principale prend appui sur le cadre conceptuel offert par la notion de « principe de précaution » dont les premières formulations remontent du début des années 1970, et qui avaient précisément pour objectif de remédier aux défaillances des outils et méthodes d’évaluation scientifique traditionnelles. La thèse est divisée en cinq parties. Commençant par une revue historique des modèles classiques des théories de la conception (design thinking) elle se concentre sur l’évolution des modalités de prise en compte de la durabilité. Dans cette perspective, on constate que les théories de la « conception verte » (green design) datant du début des années 1960 ou encore, les théories de la « conception écologique » (ecological design) datant des années 1970 et 1980, ont finalement convergé avec les récentes théories de la «conception durable» (sustainable design) à partir du début des années 1990. Les différentes approches du « principe de précaution » sont ensuite examinées sous l’angle de la question de la durabilité du projet. Les standards d’évaluation des risques sont comparés aux approches utilisant le principe de précaution, révélant certaines limites lors de la conception d’un projet. Un premier modèle théorique de la conception intégrant les principales dimensions du principe de précaution est ainsi esquissé. Ce modèle propose une vision globale permettant de juger un projet intégrant des principes de développement durable et se présente comme une alternative aux approches traditionnelles d’évaluation des risques, à la fois déterministes et instrumentales. L’hypothèse du principe de précaution est dès lors proposée et examinée dans le contexte spécifique du projet architectural. Cette exploration débute par une présentation de la notion classique de «prudence» telle qu’elle fut historiquement utilisée pour guider le jugement architectural. Qu’en est-il par conséquent des défis présentés par le jugement des projets d’architecture dans la montée en puissance des méthodes d’évaluation standardisées (ex. Leadership Energy and Environmental Design; LEED) ? La thèse propose une réinterprétation de la théorie de la conception telle que proposée par Donald A. Schön comme une façon de prendre en compte les outils d’évaluation tels que LEED. Cet exercice révèle cependant un obstacle épistémologique qui devra être pris en compte dans une reformulation du modèle. En accord avec l’épistémologie constructiviste, un nouveau modèle théorique est alors confronté à l’étude et l’illustration de trois concours d'architecture canadienne contemporains ayant adopté la méthode d'évaluation de la durabilité normalisée par LEED. Une série préliminaire de «tensions» est identifiée dans le processus de la conception et du jugement des projets. Ces tensions sont ensuite catégorisées dans leurs homologues conceptuels, construits à l’intersection du principe de précaution et des théories de la conception. Ces tensions se divisent en quatre catégories : (1) conceptualisation - analogique/logique; (2) incertitude - épistémologique/méthodologique; (3) comparabilité - interprétation/analytique, et (4) proposition - universalité/ pertinence contextuelle. Ces tensions conceptuelles sont considérées comme autant de vecteurs entrant en corrélation avec le modèle théorique qu’elles contribuent à enrichir sans pour autant constituer des validations au sens positiviste du terme. Ces confrontations au réel permettent de mieux définir l’obstacle épistémologique identifié précédemment. Cette thèse met donc en évidence les impacts généralement sous-estimés, des normalisations environnementales sur le processus de conception et de jugement des projets. Elle prend pour exemple, de façon non restrictive, l’examen de concours d'architecture canadiens pour bâtiments publics. La conclusion souligne la nécessité d'une nouvelle forme de « prudence réflexive » ainsi qu’une utilisation plus critique des outils actuels d’évaluation de la durabilité. Elle appelle une instrumentalisation fondée sur l'intégration globale, plutôt que sur l'opposition des approches environnementales. / This thesis is a contribution to the general theory of design thinking. In the prevalent demand for a sustainable development, the main objective of this research is the construction of a theoretical model of design thinking that contextualizes standard sustainability evaluation tools. The basis of these normative tools is analyzed in four dimensions: ontological, methodological, epistemological and teleological. Indications of potential counter-productive effects of these norms for design thinking confirm the need for a theory of qualitative judgment. Our central hypothesis revolves around the benefits of the underlying conceptual framework of the ‘precautionary principle’ for design thinking, the first formulations of which goes back to the early seventies in Germany, and was in fact created as a way to address the failures of traditional scientific evaluation tools or methods. The thesis comprises five parts. Beginning with a historical perspective, a review of classical models of design thinking, specifically focuses on the evolving approaches for addressing sustainable development. Theories of “green design” coming from the early sixties, theories of ecological design of the seventies and eighties are finally converging on the developing theories of “sustainable design” formulated in the early nineties. The underlying theories of the precautionary principle are then reviewed and explored for the specific context of design within the perspective of sustainability. Current methods of standard risk assessment methods are compared to a precautionary approach, revealing their conceptual limits for design thinking. A preliminary theoretical model for design thinking is then constructed adopting the theories underlying the precautionary principle. This model represents a global vision for judging the design project in a context of sustainability, rather than on traditional approaches for risk assessment, which are purposive and instrumental. The precautionary principle is further explored for the specific context of architectural design. This exploration begins with a historical perspective of the classical notion of ‘prudence’ for guiding architectural judgment. In light of the contemporary issues related to sustainability, we then examine the challenges of judging architectural projects given the increasing international prominence of such standard evaluation methods (i.e. Leadership in Energy and Environmental Design, LEED). The thesis proposes a reinterpretation of design thinking as proposed by Donald A. Schön is introduced such that the use of tools, like LEED can be contextualized. This exercise reveals an epistemological barrier, which shall be taken into consideration when reformulating the theoretical model. In accordance with a constructivist epistemology, a new theoretical model is therefore confronted to the study and illustration of three contemporary Canadian architectural competitions adopting the standard evaluation method LEED. A preliminary set of ‘tensions’ identified in the judgment process and design thinking is further categorized into their conceptual counterparts. These are: (1) analogical/logical conceptualization; (2) epistemological/methodological uncertainty; (3) interpretive/analytic comparability; and (4) universal/contextual relevance of the proposal. These conceptual tensions are considered as vectors that come into correlation with the theoretical model, enriching it, yet without validating it, in the positivist sense of the word. These confrontations with the real, help better define the epistemological barrier identified above. This thesis therefore highlights the often underestimated impact of environmental standards on the judgment process and design thinking, with particular, albeit non restrictive, reference to contemporary Canadian architectural competitions for public buildings. It concludes by stressing the need for a new form of “reflective prudence” in design thinking along with a more critical use of current evaluation tools for sustainability founded on a global integration rather than on the opposition of environmental approaches.
274

A window into selective catalytic reduction : a RAIRS study of NO and NH3 on Cu{311}

Sitathani, Krit January 2017 (has links)
This thesis studies the interaction between the bare Cu{311} surface with NO and NH3,individually and co-adsorbed using reflection-absorption infrared spectroscopy (RAIRS). In addition to the bare Cu{311} surface, the interaction of NO and NH3 with the various oxygen phases of the Cu{311} surface phases was also studied. Several other techniques were used in tandem to support the study, such as low energy electron diffraction (LEED) and temperature programmed desorption (TPD) experiments using mass spectrometry. The study was carried out in pursuit an understanding of the underlying mechanism of the selective catalytic reduction (SCR) of NO using NH3 in current diesel engines. The dosing of NO onto the Cu{311} surface at 100 K leads to the initial adsorption of intact NO. After an exposure threshold is reached, individual NO molecules react with another NO molecule to form (NO)2 dimers. These dimer species subsequently form N2O, leaving O(a) on the surface. Oxygen was found to be an inhibitor for the reaction, either due to the reaction in a self-poisoning process or from oxygen pre-dosing onto the Cu{311} surface. Temperature plays a minor role with regards to NO/Cu{311}, as it only affects the amount of NO on the surface along with adsorbate surface mobility. Similarly, NH3 was found to adsorb intact onto the Cu{311} surface and not to react or dissociate at 100 K. Oxygen acts as a site blocker for the adsorption, but can also stabilise NH3 to remain on the surface at higher temperatures due to electronic effects. At 300 K, it was found that both the bare and oxygen pre-covered Cu{311} surface was able to dissociate NH3 into NH2. The co-adsorption of NO and that of NH3 onto the Cu{311} surface were found to be largely independent of each other and the interaction is dominated by the displacement of NO by NH3. However, as NO adsorption on the Cu{311} surface forms O(a), it indirectly affects the adsorption of NH3 by creating an oxygen covered Cu{311} surface, which changes how NH3 adsorbs onto the surface.
275

Development of a Spin-Polarized Low Energy Electron Diffraction System and Investigation on Spin-Orbit and Exchange Interactions on Ir(100) and Ultrathin Fe(100) Grown on Ir(100)

Pradeep, A V January 2016 (has links) (PDF)
Spin-polarized electron beam has not yet been produced from an unpolarized electron beam using Stern-Gerlach type spin filter, because of the Lorentz force and Heisenberg uncertainty principle. At present, electron spin detectors and filters work on the basis of spin-dependent scattering of an electron beam from crystal surfaces. Single channel efficiencies of all the spin detectors for electrons are orders of magnitudes lower than the ideal one. Specular reflection type spin-polarized low energy electron diffraction (SPLEED)-spin detectors are having higher single channel efficiencies compared to the conventional Mott detectors. Moreover, multichannel detection can be realized from specular reflection type SPLEED-spin detectors. They have higher effective efficiency than the ideal spin detector. In order to develop specular reflection type spin filter, it is important to develop a spin-polarized low energy electron diffraction system. In addition, SPLEED system allows us to study the spin-orbit and exchange scattering at crystal surfaces. The general direction of the thesis has been the development of spin-polarized low energy electron diffraction (SPLEED) system. This system has been used to investigate the spin-orbit interactions on Ir(100) surface and exchange interactions of Fe grown on Ir(100). The thesis is organized into chapters as follows. Chapter 1 introduce the reader to some of the basic concepts of polarized electrons and the evolution of spin-polarized electron sources and detectors. Sources of polarized electrons are discussed with emphasis on photocathodes such as GaAs and strained GaAs. Widely used spin detector is the Mott detector which works in the higher energy range. The working principle of the Mott detector is discussed. Commonly used spin detector in the lower energy range is the LEED detector. The concept of the LEED detector is also discussed. Working principle and recent developments of specular reflection type SPLEED spin filters are introduced. Evolution of electron spin detector is discussed towards the end of the chapter. Chapter 2 discusses about the two instruments designed and developed during the course of the thesis. The first one is a spin-polarized low energy electron diffraction system working in the reflected electron pulse counting mode in UHV. This system is capable of measuring spin asymmetries due to spin-orbit interaction and exchange interaction. This instrument is useful in understanding structure and magnetism at surfaces as well as helps to develop new spin polarimeter based on SPLEED by evaluating spin asymmetries from different surfaces. All instruments connected to SPLEED system, measurement protocol and controlling software are discussed with some details. Along with this, standard characterization tools such as X-ray diffraction and magneto-optic Kerr effect measurements are discussed. The second instrument is a novel quadratic magneto-optic Kerr effect measurement system using permanent magnets, which is simple, compact and cost-effective. We have used rotating field method to extract QMOKE component in saturation. So there is no need for precise real-time measurement of magnitude and direction of the magnetic field as in the case of vector magnet. This instrument can easily quantify QMOKE coefficients for ferrimagnetic and ferromagnetic thin films and single crystals. Chapter 3 discusses SPLEED experiments carried out on Ir(100)-(1×5)-Hex and Ir(100)-(1×2+2×1)-O surfaces. The surface structure and surface preparation techniques are discussed. The stability of the Ir(100)-(1×5)-Hex surface is evaluated by monitoring the spin asymmetry as the function of time. Within 25 hours after the surface preparation, the profile of the spin asymmetry and the reflected electron count for Ir(100)-(1×5)-Hex surface resembles that of hydrogen adsorbed Ir(100)-(1×5)-H surface. The electron energy-angle of incidence landscape of reflectivity, spin asymmetry and figure of merit are recorded for Ir(100)-(1×2+2×1)-O surface. Many wide regions with a large figure of merit are identified in the E- landscape. Chapter 4 reports SPLEED experiments carried out on Ir(100)-(1×5)-H surface. The comparison between asymmetries evaluated for the Ir(100)-(1×5)-Hex surface after 25 hours and Ir(100)-(1×5)-H surface suggests that Ir(100)-(1×5)-Hex surface is transforming to Ir(100)-(1×5)-H surface, in 25 hours. This can be due to the adsorption of more than four Langmuir of residual hydrogen during this time. The energy-angle landscape of reflectivity, asymmetry and figure of merit are recorded for Ir(100)-(1×5)-H surface in an energy range 20 eV to 100 eV and angle range 10 to 60 . Many regions are identified as the working point for specular reflection type spin filter based on SPLEED. The surface structure and surface preparation techniques are discussed. The stability of the surface is also evaluated. Chapter 5 investigates the growth and magnetic properties of Fe(100) film on Ir(100)-(1×1), Ir(100)-(1×5)-Hex and Ir(100)-(1×2+2×1)-O surfaces. LEED, MEED, LMOKE and QMOKE studies were presented. The growth is found to be layer-by-layer at least up to 20 monolayers (ML) at room temperature. At higher deposition temperature, the MEED oscillations disappear around 3-5 ML. Magnetic anisotropy of the Fe(100) film grown on Ir(100)-(1×2+2×1)-O surfaces is evaluated using LMOKE measurement using Kerr microscope. Simultaneous in-situ LMOKE and MEED measurements were carried out during the deposition. Ferromagnetic ordering with an in-plane easy axis starts above 4.5 ML at room temperature. The Kerr rotation normalized by thickness is evaluated in the pseudomorphic regime and strain relaxed regime. The probing depth of the MOKE is found to be around 14 nm in Fe(100)/Ir(100). An antisymmetric component is observed in the re-magnetization loop measured using MOKE. This antisymmetric loop arises due to the quadratic magneto-optic coupling which is separated by symmetrization and antisymmetrization procedure. The observed quadratic magneto-optic coupling suggests that the analysis based on the assumption that the magneto-optic coupling is linear in magnetization has to be modified. In order to quantify the quadratic magneto-optic coupling parameters, a QMOKE measurement system is developed and measurements were carried out. Chapter 6 discusses SPLEED experiments carried out on various thicknesses of Fe(100) film. Fe(100) films grown on Ir(100) substrate with the thickness less than or equal to 4 ML is not ferromagnetic with in-plane easy axis at room temperature. The non-zero exchange asymmetry observed for 5 ML and above indicates the presence of ferromagnetic ordering. A difference in the profile of exchange asymmetry is observed between pseudomorphic and strain relaxed regime. Large spin-orbit asymmetry is observed for 1 ML and 2 ML Fe(100) which is unexpected from a low atomic number (Z) material. The reason for large spin-orbit asymmetry is still unknown. The energy-angle landscape of reflectivity, exchange asymmetry, spin-orbit asymmetry and figure of merit were evaluated for 21 ML of Fe(100). Many working points were identified for different types multichannel spin filter based on exchange interaction Finally, the various results are summarized and a broad outlook is given.
276

Vzduchotechnika pro budovy s téměř nulovou spotřebou energie / Ventilation of nearly Zero Energy Building

Frčka, Lukáš January 2020 (has links)
This diploma thesis is focused on nearly zero energy buildings, which are a mandatory part of construction of the buildings in Czech republic after 2020. It also deals with HVAC and its design as part of these buildings. The theoretical part deals with legal and technical regulations and possible savings in HVAC systems. The computational part is focused on two solution of HVAC systems in given object. The project part is about the given object, which is otevřená zahrada Brno. This building was founded by Nadace Partnerství s.r.o.. This third part of diploma thesis deals with the quality of indoor microclimate and evaluation of the heat recovery system effiency, which is applied in local HVAC unit.
277

Praseodymia on non-passivated and passivated Si(111) surfaces

Gevers, Sebastian 04 July 2011 (has links)
In the presented thesis thin praseodymia films on non-passivated and passivated Si(111) substrates were investigated. The first part deals with PDA of praseodymia films with fluorite structure under UHV conditions in the temperature region from RT to 600°C. Here, a sophisticated model of the annealing process of praseodymia films is established. This is done by detailed analysis of XRD measurements using the kinematic diffraction theory in combination with the analysis of GIXRD, XRR and SPA-LEED measurements. It is shown that the untreated films, which are oxidized in 1 atm oxygen to obtain fluorite structure, do not exhibit pure PrO2 stoichiometry as it was assumed before. Instead, they decompose into two laterally coexisting species exhibiting a PrO2 and a Pr6O11. oxide phase, respectively. These species are laterally pinned to the lattice parameter of bulk Pr6O11. Homogeneous oxide films with Pr6O11 phase can be observed after annealing at 100°C and 150°C. Here, lateral strain caused by the pinning of the species is minimized and an increase of the crystallite sizes is determined. If higher annealing temperatures are applied, the film decomposes again into two coexisting species. Finally, after annealing at 300°C, a mixed crystalline film with both Pr2O3 and Pr2O3+Delta oxide phases is formed, where Delta denotes a considerable excess of oxygen within the sesquioxide phase. Again the lateral strain increases due to the tendency of praseodymia phases to increase their lattice parameters during oxygen loss combined with the lateral pinning. This is accompanied by a decrease of crystallite sizes, which are afterwards comparable to those of the untreated films. Further annealing at temperatures above 300°C does not significantly change the structure of the oxide film. However, the increase of the amorphous Pr-silicate interface between Si substrate and oxide at the expense of the crystalline oxide can be observed after annealing at higher temperatures. Furthermore, an increased mosaic spread of the crystallites occurs, which reduces the lateral strain caused by the oxygen loss. Nevertheless, the crystalline structure is stable against further annealing up to temperatures of 600°C. Transportation of the sample under ambient conditions after annealing at 200°C and 300°C leads to the formation of an additional crystalline structure at the surface which cannot be allocated to any praseodymia phase and may be explained by the contamination of the topmost crystalline layers with Pr-hydroxides. The results obtained from praseodymia films annealed in 1 atm nitrogen show that these films are good candidates to form homogeneous oxide films with pure cub-Pr2O3 structure by subsequent annealing in UHV. Here, a single oxide species is already observed after annealing at 300°C by SPA-LEED measurements which is in contrast to praseodymia films with fluorite structure where higher annealing temperatures (600°C) are necessary. In this case, negative effects like interface growth or increased defect density (mosaics, grain boundaries) can be minimized. Investigations on oxygen plasma-treated praseodymia films to obtain pure PrO2 stoichiometry are presented in the second part. Oxygen plasma-treated samples are compared with samples oxidized in 1 atm oxygen regarding the structure of the crystalline film. For this purpose, XRR and XRD measurements are performed to get structural information of the oxide film, which can be used to identify the corresponding oxide phases. Here, significantly smaller lattice constants of the crystalline oxide species can be observed after plasma treatment, which points to the incorporation of additional oxygen atoms. This verifies former studies, where a higher oxidation state of the oxide film was found by XPS measurements and it shows that plasma-treated films exhibit a higher oxidation state than films oxidized in 1 atm oxygen due to the availability of reactive atomic oxygen in the plasma. Furthermore, the Pr-silicate interface between crystalline film and Si substrate is not increased during plasma treatment. In the last part of the presented thesis, first results from the epitaxy of praseodymia films on Cl-passivated Si substrates are shown. The aim is to suppress the Pr-silicate formation during the growth process. Thus, praseodymia films are grown on passivated and non-passivated substrates to compare the crystallinity of both samples using XSW and LEED measurements. The structure of the oxide films on Cl-passivated Si is determined afterwards by XRR. It is shown that crystalline films with cub-Pr2O3 structure and several nanometer thickness can be successfully grown on Cl-passivated substrates. Here, the Pr-silicate interface layer are restricted to a single mono-layer. In contrast, the films grown on non-passivated substrates are completely amorphous containing Pr-silicates and Pr-silicides.
278

Příprava realizace Vysokoškolských kolejí VUT v Brně / Preparation of realization of University dormitory BUT

Götz, Libor Unknown Date (has links)
The aim of this diploma thesis is to prepare the realization of college dormitories for the Brno University of Technology. A technical docummentation for the construction-technological project, transport routes design, time and financial schedule, budget according to technical – economic indicators, main technological stages implementation study, construction project, main construction machines proposal, time plan, and an item budget of the main construction object is prepared. An integral part of this thesis are the technological regulations, including control and test plans. And at the end the LEED certification and the health and safety plan were prepared.
279

Mateřská škola Kuřim - stavebně technologický projekt / Kindergarten Kuřim - construction technology project

Kurka, Jan Unknown Date (has links)
The subject of the thesis is the solution of selected parts of the construction technology project of the construction of a kindergarten in Kuřim on Hybešova Street. It is a single-story brick building with a flat roof with a green roof. In my work I solve the study of the main technological stages, technological regulations for the monolithic ceiling structure and the green roof of the Smart Roof Solutions system together with inspection and test plans, design of the main construction machines, time and a financial plan for the main building of the kindergarten, the building time and financial plan for the entire construction plan, the balance of workers and the deployment of construction machinery and the construction site equipment project. Then I add a noise study, assessment of selected LEED 2009 Core & Shell credits, design of the TOPSAFE restraint system, health and safety plan, documentation of the green roof of the Smart Roof Solutions system and a search on the topic of green roofs.
280

Příprava realizace Rezidence Bučovických teras / Preparation for the implementation of the Bučovice Terrace Residence

Loukota, Michal Unknown Date (has links)
The subject of the diploma thesis is the implementation of apartment buildings in Bučovice, specifically focusing on the apartment building "X". It deals with a construction technology project. Its content is a technical report on the construction technology project, traffic relations for the transport of materials and machines to the construction site, technical report on the construction site equipment, construction technology study, machine design, elaboration of technological regulation for monolithic ceiling construction and infiltration tank. The chapters on safety and health protection at work on the construction site, the LEED certification system and a noise study for earthworks are also elaborated. Several diagrams of the procedure of execution of individual constructions, time and financial plan, selected details are elaborated. The thesis contains 30 appendices.

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