The yeast SWI/SNF complex is the prototype of a subfamily of ATP-dependent chromatin remodeling complexes. It consists of eleven stoichiometric subunits including Swi2p/Snf2p, Swi1p, Snf5p, Swi3p, Swp82p, Swp73p, Arp7p, Arp9p, Snf6p, Snf11p, and Swp29p, with a molecular weight of 1.14 mega Daltons. Swi2p/Snf2p, the catalytic subunit of SWI/SNF, is evolutionally conserved from yeast to human cells. Genetic evidence suggests that SWI/SNF is required for the transcriptional regulation of a subset of genes, especially inducible genes. SWI/SNF can be recruited to target promotors by gene specific activators, and in some cases, SWI/SNF facilitates activator binding. Biochemical studies have demonstrated that purified SWI/SNF complex can hydrolyze ATP, and it can use the energy from ATP hydrolysis to generate superhelical torsion, mobilize mononucleosomes, enhance the accessibility of endonucleases to nucleosomal DNA, displace H2A/H2B dimers, induce dinucleosome and altosome formation, or evict nucleosomes. A human homolog of Swi2p/Snf2p, BRG1, is the catalytic subunit of the human SWI/SNF complex. Interestingly, isolated BRG1 alone is able to remodel a mononucleosome substrate. Importantly, mutations in mammalian SWI/SNF core subunits are implicated in tumorigenesis. Therefore, it remains interesting to characterize the role(s) of each subunit for SWI/SNF function. In this thesis project, I dissected SWI/SNF chromatin remodeling function by investigating the role of the SANT domain of the Swi3p subunit. Swi3p is one of the core components of SWI/SNF complex, and it contains an uncharacterized SANT domain that has been found in many chromatin regulatory proteins. Earlier studies suggested that the SANT domain of Ada2p may serve as the histone tail recognition module. For Swi3p, a small deletion of eleven amino acids from the SANT domain caused a growth phenotype similar to that of other swi/snf mutants. In chapter I, I have reviewed recent findings in the function of chromatin remodeling complexes and discuss the molecular mechanism of their action. In chapter II, I characterized the role of the SANT domain of Swi3p. I found that deletion of the SANT domain caused a defect in a genome-wide transcriptional profile, SWI/SNF recruitment, and more interestingly impairment of the SANT domain caused the dissociation of SWI/SNF into several subcomplexes: 1) Swi2p/Arp7p/Arp9p, 2) Swi3p/Swp73p/Snf6p, 3) Snf5p, and 4) Swi1p. Artificial tethering of SWI/SNF onto a LacZ reporter promoter failed to activate the reporter gene in the absence of the SANT domain, although Swi2p can be recruited to the LacZ promoter. We thus demonstrated that the Swi3p SANT domain is critical for Swi3p function and serves as a protein scaffold to integrate these subcomplexes into an intact SWI/SNF complex. In Chapter III, I first characterized the enzymatic activity of the subcomplexes, especially the minimal complex of Swi2p/Arp7p/Arp9p. We found that this minimal subcomplex is fully functional for chromatin remodeling in assays including cruciform formation, restriction enzyme accessibility in mononucleosomal and nucleosomal array substrates, and mononucleosome mobility shift. However, it is defective in ATP-dependent removal of H2A/H2B dimers. Moreover, we found that Swi3p and the N-terminal acidic domain of Swi3p strongly interact with GST-H2A and H2B but not GST-H3 or H4 tails. We purified a SWI/SNF mutant (SWI/SNF-Δ2N) that lacks 200 amino acids within the N-terminal acidic domain of Swi3p. Intriguingly, SWI/SNF-Δ2N failed to catalyze ATP-dependent dimer loss, although this mutant SWI/SNF contains all the subunits and has intact ATP-dependent activity in enhancing restriction enzyme accessibility. These data help to further understand the molecular mechanism of SWI/SNF, and show that H2A/H2B dimer loss is not an obligatory consequence of ATP-dependent DNA translocation, but requires the histone chaperone function of the Swi3p subunit. Based on these findings, we proposed a new model of the structural and functional organization of the SWI/SNF chromatin remodeling machinery: SWI/SNF contains at least four distinct modules that function at distinct stages of the chromatin remodeling process. 1) Swi1p and Snf5p modules directly interact with gene specific activators and function as the recruiter; 2) Swi2p/Arp7p/Arp9p generates energy from ATP hydrolysis and disrupts histone/DNA interactions; and 3) Swi3p/Swp73p/Snf6p may play dual roles by integrating each module into a large remodeling complex, as well as functioning as a histone H2A/H2B chaperone to remove dimers from remodeled nucleosomes. Chapter IV is a perspective from current work in this project. I first discuss the interest in further characterizing the essential role of Snf6p, based on its activation of LacZ reporter on its own. Using in vitro translated protein and co-IP studies, I tried to pinpoint the requirement of the SANT domain for SWI/SNF assembly. I found that Swi3p directly interacts with Swp73p, but not with other subunits. When Swi3p is first incubated with Swp73p, Swi3p also interacts with Snf6p, indicating that Swi3p indirectly interacts with Snf6p, therefore forming a subcomplex of Swi3p/Swp73p/Snf6p. This subcomplex can also be reconstituted using in vitro co-translation. Consistent with the TAP preparation of this subcomplex, partial deletion of the SANT domain of Swi3p does not affect the assembly of Swi3p/Swp73p/Snf6p in vitro. However, the assembly of SWI/SNF complex was not detected in the presence of eight essential in vitro translated subunits or from co-translation of all the subunits. I have discussed the interest in further characterizing the histone chaperone role of the Swi3p N-terminal acidic domain and the role of other core subunits of SWI/SNF such as Snf6p for transcriptional regulation.

De nos jours, l'intégration des opérations de désassemblage lors de la conception des produits est un enjeu crucial. On estime que dans la phase initiale de la conception d'un produit, le coût des opérations de désassemblage représente environ 30% de son coût total. Ainsi, la simulation des opérations de désassemblage de produits industriels trouve un fort intérêt pour des simulations interactives grâce à des programmes d'immersion et en temps réel. Dans ce contexte, dans un premier temps, cette thèse présente une méthode de génération des séquences de désassemblage possibles pour le désassemblage sélectif. La méthode est basée sur les niveaux les plus bas du graphe de désassemblage des produits. Au lieu de considérer les contraintes géométriques pour chaque paire de composants, la méthode proposée tient compte des contacts (relations géométriques entre les composants) et des collisions afin de générer le Graphe Géométrique de Contacts et de Désassemblage (DGCG). Celui-ci est ensuite utilisé pour la génération des séquences de désassemblage permettant ainsi de réduite le nombre de séquences possibles en ignorant les composants non liés avec la cible. Une application de simulation a été développée, intégrée dans un environnement de réalité virtuelle (RV) permettant ainsi la génération du nombre minimum de séquences possibles de désassemblage.Dans un second temps, une méthode d'évaluation des opérations de désassemblage par analyse géométrique 3D de l'amovibilité dans un environnement RV est proposée. Elle est basée sur sept nouveaux critères qui sont: la visibilité d'une pièce, les angles de désassemblage, le nombre des changements d'outils, le changement d'orientation des trajectoires, la stabilité des sous-ensembles, les angles de rotation du cou et flexion du corps. Tous ces critères sont présentés par des coefficients sans dimension calculés automatiquement par l'application développée, permettant ainsi d'évaluer la complexité des séquences de désassemblage. A cet effet, un environnement mixte de réalité virtuelle pour le désassemblage (VRDE) est développé, basé sur le langage de programmation Python, en utilisant deux bibliothèques : VTK (Visualisation Toolkit) et ODE (Open Dynamics Engine), les formats d'échange étant fichiers: STEP, WRL et STL. L'analyse des résultats obtenus démontrent la fiabilité de l'approche proposée fournissant ainsi une aide non négligeable pour l'évaluation des séquences de désassemblage lors de processus de développement de produits (PDP). Les autres conséquences de ce travail consistent à classer les critères en fonction de leur importance. A cet effet, des coefficients de modération peuvent être attribués à chacun d'eux permettant ainsi une méthode d'évaluation plus complète. / Integration of disassembly operations during product design is an important issue today. It is estimated that at the earliest stages of product design, the cost of disassembly operations almost represents 30 % of its total cost. Nowadays, disassembly operation simulation of industrial products finds a strong interest in interactive simulations through immersive and real-time schemes. In this context, in the first place, this thesis presents a method for generating the feasible disassembly sequences for selective disassembly. The method is based on the lowest levels of a disassembly product graph. Instead of considering the geometric constraints for each pair of components, the proposed method considers the geometric contact and collision relationships among the components in order to generate the so-called Disassembly Geometry Contacting Graph (DGCG). The latter is then used for disassembly sequence generation thus allowing the number of possible sequences to be reduced by ignoring any components which are unrelated to the target. A simulation framework was developed integrated in a Virtual reality environment thus allowing generating the minimum number of possible disassembly sequences. Secondly, a method for disassembly operation evaluation by 3D geometric removability analysis in a Virtual environment is proposed. It is based on seven new criteria which are: visibility of a part, disassembly angles, number of tools' changes, path orientation changing, sub-assembly stability, neck score and bending score. All criteria are presented by dimensionless coefficients automatically calculated, thus allowing evaluating disassembly sequences complexity. For this purpose, a mixed virtual reality disassembly environment (VRDE) is developed based on Python programming language, utilizing VTK (Visualization Toolkit) and ODE (Open Dynamics Engine) libraries. The framework is based on STEP, WRL and STL exchange formats. The analysis results and findings demonstrate the feasibility of the proposed approach thus providing significant assistance for the evaluation of disassembly sequences during Product Development Process (PDP). Further consequences of the present work consist in ranking the criteria according to their importance. For this purpose, moderation coefficients may be allocated to each of them thus allowing a more comprehensive evaluating method.

abstract: Today, we use resources faster than they can be replaced. Construction consumes more resources than any other industry and has one of the largest waste streams. Resource consumption and waste generation are expected to grow as the global population increases. The circular economy (CE) is based on the concept of a closed-loop cycle (CLC) and proposes a solution that, in theory, can eliminate the environmental impacts caused by construction and demolition (C&D) waste and increase the efficiency of resources’ use. In a CLC, building materials are reused, remanufactured, recycled, and reintegrated into other buildings (or into other sectors) without creating any waste. Designing out waste is the core principle of the CE. Design for disassembly or design for deconstruction (DfD) is the practice of planning the future deconstruction of a building and the reuse of its materials. Concepts like DfD, CE, and product-service systems (PSS) can work together to promote CLC in the built environment. PSS are business models based on stewardship instead of ownership. CE combines DfD, PSS, materials’ durability, and materials’ reuse in multiple life cycles to promote a low-carbon, regenerative economy. CE prioritizes reuse over recycling. Dealing with resource scarcity demands us to think beyond the incremental changes from recycling waste; it demands an urgent, systemic, and radical change in the way we design, build, and procure construction materials. This dissertation aims to answer three research questions: 1) How can researchers estimate the environmental benefits of reusing building components, 2) What variables are susceptible to affect the environmental impact assessment of reuse, and 3) What are the barriers and opportunities for DfD and materials’ reuse in the current design practice in the United States. The first part of this study investigated how different life cycle assessment (LCA) methods (i.e., hybrid LCA and process-based LCA), assumptions (e.g., reuse rates, transportation distances, number of reuses), and LCA timelines can affect the results of a closed-loop LCA. The second part of this study built on interviews with architects in the United States to understand why DfD is not part of the current design practice in the country. / Dissertation/Thesis / Doctoral Dissertation Civil, Environmental and Sustainable Engineering 2018

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A ubiquitous household appliance, the washing machine currently sees a fall in its usage life to a mere 7 years, with valuable and finite resources getting lost to the landfill faster than ever. The reason?  Mechanical obsolescence and barriers in repair that make helpless users as far removed from the process as possible. The goal of my degree project is to create long lasting product and service experiences through easier channels of repair and to design deeper partnerships between humans and the appliances that surround them. I want to be part of a rising sustainability movement that aims for a seismic shift in thinking by creating resilient product experiences.  Can the key to a sustainable future be appliances that last for generations?

Bell (Gigli, et al. 2007:ix) believes that “design that is good should be embedded within all that surrounds us in the unnatural world. Good design and good architecture improve all our lives - they are not just about decoration.” An understanding of what good design entails and a comprehension of the interior designer’s role within the built environment and public realm could anchor this belief. The International Federation of Interior Architects/Designers (IFI) established Design Frontiers: The Interiors Entity (DFIE) to define the interiors discipline for IFI stakeholders and the general public alike. The planned Interiors Biennale in 2013, the final phase of the DFIE, is intended to visualise this knowledge, actualising the global consensus as reflected in the IFI Interiors Declaration. The objective of the dissertation is to design a travelling exhibition for the IFI Interiors Biennale 2013. The study investigates exhibition design as a method of communicating the seven basic pillars of the interiors profession as described by the Declaration. A normative position derived from the event title, ‘designing from the inside out’, establishes the premise for the design approach. The project explores the temporary imprint that results from the relationship between the general (host structure) and the specific (installation). While acknowledging that the design cannot be completely site specific, the proposal identifies characteristics of ‘the universal exhibition host’ to obtain a set of constraints that inform the design of a travelling installation. A proto-site is identified within Johannesburg, embodying the universal specification. The site typology has the least impact on the design development with the event typology (travelling exhibition), and the design brief (IFI Interiors Declaration) driving the process. The investigation points to an adaptive solution: design for disassembly. This design philosophy influences the chosen construction and fabrication method as well as the selected material type. The design objective is not to curate the event, but rather to provide a flexible and innovative ‘kit of parts’ to facilitate the projected communication needs of the client (IFI). / Dissertation (MInt(Prof))--University of Pretoria, 2011. / Architecture / unrestricted

I takt med att fler stora byggnader uppförs i trä ökar medvetenheten om resurshantering. Förbanden i dagens träbyggnader sågas isär och bränns vid rivning på grund av att förbandet inte går att demontera. Demonterbara förband skulle möjliggöra flyttandet av byggnader eller materialåteranvändning av bärande element. För att svara på forskningsfrågan ”Hur kan förband i limträkonstruktioner utformas, med dagens gängse beräkningsmetoder, för att möjliggöra demontering?” studeras en hallbyggnad som projekterats av Sweco. Två förbandstyper, pelar-balk och balk-balk, väljs för utformning av demonterbara förbandslösningar. Flexibel aktionsforskningsmetod har använts i problemlösande syfte. Insamlade data består av kvalitativa dialoger med sakkunniga och kvantitativa beräkningar.  Resultatet av studien är utformningen av två förband med genomgående skruvar. Pelar-balk-förbandet utformas med 8 genomgående skruvar, trälaskar och en invändig ståldymling. Balk-balk-förbandet utformas med en dold balksko med sidoplåtar och totalt 17 genomgående skruvar. Utformningarna med genomgående skruvar anses enkelt demonterbara och dessutom bra ur arbetsmiljösynpunkt. Pelar-balk-förbandets ursprungliga utformning har 72 träskruvar, vars skruvskallar döljs helt av trä och därför inte kan dras ut. Balk-balk-förbandets ursprungliga utformning består av 322 ankarspikar och 26 träskruvar som på grund av förbindarnas antal gör demonteringen så tidskrävande att den inte skulle utföras alls.  Examensarbetet landar i slutsatsen att det går att utforma förband för demonterbarhet genom att välja bort spik och träskruv till förmån för genomgående skruv. Förbanden som tagits fram under studien rekommenderas i byggnader där demonterbarhet eftersträvas. / As more large buildings are built in wood, awareness of resource management increases. The joints in today's wooden buildings are sawn apart and incinerated during demolition due to the fact that the joint cannot be disassembled. Demountable joints would enable the relocation of buildings or the reuse of load-bearing elements. To answer the research question "How can joints in glulam constructions be designed, with today's common calculation methods, to enable disassembly?" an industrial building designed by Sweco is being studied. Two joint types, column-beam and beam-beam, are selected for the design of demountable joint solutions. Flexible action research method has been applied in order to solve a problem. Collected data consists of qualitative dialogues with experts and quantitative calculations.  The result of the study is the design of two bolted joints. The column-beam joint is designed with 8 bolts, external wooden straps and an internal steel dowel. The beam-beam joint is designed with a hidden beam shoe with side plates and a total of 17 bolts. The designs with bolts are considered to be easily dismantled and also good from a work environment point of view. The original design of the column-beam joint has 72 wood screws. The screw´s heads are completely enclosed by wood and therefore cannot be pulled out. The original design of the beam-beam joint consists of 322 anchor nails and 26 wood screws which, due to the number of connectors, make disassembly so time-consuming that it will not not be performed at all.  This report conclude it is possible to design joints for disassembly by opting out of nails and wood screws in favor of bolts. The joints developed during the study are recommended in buildings where disassembly is wanted. / <p>Betyg 2021-06-04</p>

No description available.

The development of society calls for a new approach to traditional building systems, which no longer meet the demands of today's society. This is mainly manifested in the following points: 1. Traditional buildings, when decayed, generate a large amount of construction waste, which occupies more land and resources in the form of landfills. New buildings should aim to minimize or eliminate construction waste generation, thus reducing environmental damage. The transformation of buildings from "Cradle to Grave" to "Cradle to Cradle." 2. Different ages, social roles, and professions require varying building functionalities and sizes. Buildings should be adaptable to meet these diverse needs. 3. Buildings should not be permanently fixed to a single location but should be in a continuous process of change, even to the extent of being movable. 4. Buildings should have a growth and transformation process, where components can be recycled and reused, similar to how chemical elements can cycle naturally in the environment. 5. Buildings should be designed for rapid transport, assembly, and disassembly. They should not require specialized construction workers for installation. This is in contrast to traditional buildings with long construction periods, poor construction quality, and high levels of complexity. 6. Building design should be simplified and modular, allowing for quick achievement of aesthetic, functional, safety, and livability requirements. Owners should be able to participate in the design process, enabling them to meet their own usage and living needs. This approach differs from traditional building design, which requires extensive involvement from trained architects and engineers, resulting in higher construction costs and resource consumption. 7. New recycling houses should be adaptable for various functions and building types, such as houses, apartments, townhouses, offices, affordable housing, single-story or multi-story buildings, and even high-rise structures. 8. In summary, the concept of recycling houses aligns with the need for sustainable and adaptable buildings that minimize waste, accommodate diverse needs, promote ease of construction, and allow for resource conservation. / Master of Architecture / The development of society calls for a new approach to traditional building systems, which no longer meet the demands of today's society. This is mainly manifested in the following points: 1. Traditional buildings, when decayed, generate a large amount of construction waste, which occupies more land and resources in the form of landfills. New buildings should aim to minimize or eliminate construction waste generation, thus reducing environmental damage. The transformation of buildings from "Cradle to Grave" to "Cradle to Cradle." 2. Different ages, social roles, and professions require varying building functionalities and sizes. Buildings should be adaptable to meet these diverse needs. 3. Buildings should not be permanently fixed to a single location but should be in a continuous process of change, even to the extent of being movable. 4. Buildings should have a growth and transformation process, where components can be recycled and reused, similar to how chemical elements can cycle naturally in the environment. 5. Buildings should be designed for rapid transport, assembly, and disassembly. They should not require specialized construction workers for installation. This is in contrast to traditional buildings with long construction periods, poor construction quality, and high levels of complexity. 6. Building design should be simplified and modular, allowing for quick achievement of aesthetic, functional, safety, and livability requirements. Owners should be able to participate in the design process, enabling them to meet their own usage and living needs. This approach differs from traditional building design, which requires extensive involvement from trained architects and engineers, resulting in higher construction costs and resource consumption. 7. New recycling houses should be adaptable for various functions and building types, such as houses, apartments, townhouses, offices, affordable housing, single-story or multi-story buildings, and even high-rise structures. 8. In summary, the concept of recycling houses aligns with the need for sustainable and adaptable buildings that minimize waste, accommodate diverse needs, promote ease of construction, and allow for resource conservation.

No description available.