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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.
81

Mikroplaster från konstgräsplaner : Orsaker till spridning av mikroplaster samt en kvalitativ analys av spridningen till dränerings- och dagvattenbrunnar / Microplastics from artificial turf fields : Reasons for spreading of microplastics and a qualitative analysis of the spread to drainage and stormwater wells

Regnell, Fredrick January 2017 (has links)
Mikroplaster och dess miljöeffekter är ett forskningsområde under utveckling. Provtagning och analysmetoder försvåras av att mikroplaster kan komma från olika råvaror, vilket innebär att dess innehåll, partikelstorlek samt densitet kan variera. Det är däremot tydligt att mikroplaster är ett problem i marina miljöer då intag och ackumulering av mikro- och makroplaster har registrerats i ryggradslösa djur, fiskar, däggdjur och fåglar. Mikroplaster kan påverka bland annat matsmältningen och reproduktionen för vattenlevande djur. Mikroplaster har även registrerats i föda som är relevant för människor, men vilka effekter mikroplaster har på människor är ännu oklart. I en rapport från år 2017 uppskattade Svenska Miljöinstitutet (IVL) konstgräsplaner till att vara den näst största kvantifierade källan till spridning av mikroplaster till miljön med 1638 – 2456 ton per år, efter slitage från däck och vägar. Fotboll är en av Sveriges populäraste sporter och antalet konstgräsplaner i landet uppgick år 2016 till 1336 stycken. Till följd av att konstgräsplaner anses som en viktig källa till spridning av mikroplaster är det viktigt att utröna orsakerna till hur och varför mikroplaster sprids från konstgräsplaner och även vilka åtgärder som kan sättas in för att minska spridningen. Syftet med denna studie är att identifiera orsakerna till spridning av mikroplaster samt att presentera åtgärder som kan minska den totala spridningen av mikroplaster från konstgräsplaner. Metodiken utgick från tidigare studier av mikroplaster i vattenmiljö och vattenprover inhämtades från två konstgräsplaners dräneringsbrunnar och från en konstgräsplans lysimetrar, vilka har samlat upp vatten som har infiltrerat genom planen. Utöver detta har även fältstudier med observationer utförts vid två konstgräsplaner och samtal med driftsansvariga har bidragit med ytterligare relevant information om hur mikroplaster kan spridas. Resultaten visar att mikroplaster sprids från konstgräsplaner och att de identifierade orsakerna till spridningen, utan inbördes storleksordning, främst är: Aktivitet på planen Borstning av planen Snöröjning Regn (vilket innebär infiltration genom planen samt ytavrinning) Dessa orsaker, samt möjliga spridningsvägar för mikroplaster från en konstgräsplan till omgivningen, har visualiserats i en konceptuell modell, figur 11. Modellen har två systemgränser; det inre systemet utgörs av själva konstgräsplanen, medan det yttre systemet utgörs av närområdet runt omkring planen och kan likställas med idrottsanläggningen. Det är endast mikroplaster som sprids från det yttre systemet ut till omgivningen som bedöms kunna ha ekologiska konsekvenser. Okulära mikroskopstudier av vattenprover från dräneringsbrunnar visade på förekomst av mikroplaster. Kvantifiering av mängden fast material som kan nå dräneringsbrunnar, där mikroplaster utgör en okänd andel, uppgick till maximalt 340 – 370 kg per år och konstgräsplan med måtten 105m×65m. Mängden mikroplaster som maximalt kan infiltreras genom en konstgräsplan ner till dess dränering kvantifierades till 0,003 kg per år och konstgräsplan med måtten 105m×65m. Detta indikerar att det kan krävas mer öppna transportvägar, exempelvis öppna brunnar, för att mikroplaster ska kunna nå dräneringsbrunnar i en större viktmässig omfattning. Kvantifieringen av övriga orsaker till spridning av mikroplaster från konstgräsplaner till omgivningen är osäker, men försiktiga uppskattningar visar på att de är viktmässigt omfattande. För att mäta och säkerställa antalet partiklar som sprids från konstgräsplaner skulle mer omfattande provtagningar och analyser behöva genomföras. Konkreta åtgärder som kan tillämpas för att minska den totala spridningen av mikroplaster från konstgräsplaner är att borsta av kläder och skor innan planen eller anläggningen lämnas, informera personer som uppehåller sig vid planerna om problematiken, täcka för brunnar vid driftsaktiviteter, strategisk hantering av snöröjning, återföra granulat från anläggningen till själva planen, installera filter i brunnar samt att tömma brunnar på vatten och material. För att sätta problemet med mikroplaster från konstgräsplaner i sitt sammanhang så är det viktigt att förstå problemet i sin helhet. Vidare studier föreslås fokusera på att kvantifiera ovan nämnda orsaker till spridning av mikroplaster från konstgräsplaner, samt att kartlägga och kvantifiera spridningen utifrån de olika spridningsvägarna. / Microplastics and its environmental impacts is a research area under development. Sampling and analysis methods are complicated by the fact that microplastics may come from different raw materials, which means that its content, particle size and density may vary. It is clear that microplastics is a problem in marine environments as intake and accumulation of micro- and macroplastics have been recorded in invertebrates, fish, mammals and birds. The microplastics may affect, among other things, the digestion and reproduction of aquatic animals. The microplastics have also been recorded in foods that are relevant to humans, but what effects microplastics have on humans is still unclear. In a report from 2017, the Swedish Environmental Research Institute (IVL) estimated artificial turf fields to be the second largest quantified source for spreading the microplastics to the environment with 1638 - 2456 tons per year, after wear of tire and roads. Football is one of Sweden's most popular sports and the number of artificial turf fields in the country in 2016 reached 1336. Due to the fact that artificial turf fields is considered an important reason for the spreading of microplastics, it becomes important to investigate the reasons why and how microplastics are spread from artificial turf fields and also what measures can be taken to reduce the spread. The purpose of this study is to identify the reasons why microplastics are spread, as well as to present measures that can reduce the overall spread of microplastics from artificial turf fields. The methodology is based on previous studies of microplastics in aquatic environments and water samples were collected from drainage wells that belonged to two artificial turf fields and from a “water-infiltration-sampler” from a third field. In addition, field studies with observations have been carried out at two other artificial turf fields, and conversations with maintenance personal have provided additional relevant information on how microplastics can be spread. The results show that microplastics are spread from artificial turf fields and the identified reasons for this spreading, without specific order of magnitude, are mainly: Activity on the field Brushing of the fields Snow plowing of the fields Rain (which means infiltration through the field as well as surface runoff) These causes, as well as possible pathways for the spreading of microplastics from an artificial turf field to the surroundings, have been visualized in a conceptual model, Figure 11. The model has two system boundaries; the inner system consists of the field itself, while the outer system is the direct area around the field and can be equated with the sports facility. It is only microplastics that are spread from the outer system to the environment which is considered to cause ecological consequences. Ocular microscopy studies of water samples from drainage wells showed presence of microplastics. Quantification of the amount of solids that can reach the drainage wells, where microplastics constitute an unknown proportion, amounted to a maximum of 340 – 370 kg per year and artificial turf field measuring 105m×65m. The maximum amount of microplastics that can infiltrate through an artificial turf field down to its drainage system was quantified to 0,003 kg per year and artificial turf of 105m×65m. This indicates that more open transport routes, such as open wells, could be needed to allow microplastics to reach drainage wells to a greater extent. The quantification of other causes for the spreading of microplastics from artificial turf fields to the environment area is uncertain, but careful estimations show that they are weighty comprehensive. To measure and secure the number of particles that are spread from artificial turf fields, more extensive sampling and analysis would have to be carried out.
82

Jämförelse av konstgrässystem med avseende på luftburna partiklar / Comparison of release of airborne particles from different artificial turf systems

Nyberg, Roland, Johansson, Oskar January 2018 (has links)
Konstgräs används i stor utsträckning och dess miljöpåverkan är omdebatterad. Oro finns över spridning av mikroplaster och dess miljöpåverkan. Flera studier på spridning av större mikroplast finns, medan spridning av luftburna partiklar är mindre väl utforskat. Studier på detta är till sin natur svåra då tester i fält försvåras av förekomsten av mätbrus i form av partiklar från trafik etc. Detta arbete syftar till att i kontrollerad miljö, genom att använda en Brittisk pendelrigg, undersöka bildandet av luftburna partiklar vid yttre påverkan på konstgräs. Skillnaden mellan olika konstgrässystem studeras, i detta fall olika typer av granulat, s.k. infill. Tester körs med de tre vanligaste granulattyperna, SBR, TPE samt EPDM. I dessa tester kan skillnad påvisas mellan EPDM gentemot de andra två typerna, där EPDM ger upphov till fler luftburna partiklar. / Artificial turf is today widely used, and its environmental impact is much-debated. There are some concerns regarding the spread of microplastics and their environmental impact. Some studies regarding the spread of larger particles exist, while the impact in the form of airborne particles is less well explored. Studies on airborne particulates are quite complicated, as measuring these is made complicated by the already existing particles from traffic and such. In this study a British pendulum is utilized to, in a controlled environment, try to ascertain if a difference may exist between different types of turf. In this study the three most commonly used types of rubber granules, infill, are tested. These are SBR, TPE and EPDM. These tests show a difference in release of airborne particle between EPDM and the other two types, where EPDM generate more airborne particles.
83

Utfackningsväggar och trafikbuller - En förtätning av Albyberget / Infill walls and traffic noise - A densification of Albyberget

Granqvist, Andreas, Hall, Jonas January 2017 (has links)
AUCTORITAS Projektstyrning AB arbetar med att få fram förfrågningsunderlag för två nya flerbostadshus i en miljö som är bullerutsatt. Ett problem som uppstått är att hitta en utfackningsvägg som klarar kraven för buller samt U-värde som samtidigt är ekonomisk försvarbar. Författarna har på uppdrag av AUCTORITAS Projektstyrning AB undersökt 10 olika utfackningsväggar med hänsyn till ljudreduktion, U-värde samt pris. Syftet med arbetet var att utreda de tekniska egenskaperna för utfackningsväggarna. Frågeställningen som behandlades var följande: Hur påverkar olika materialval ljuddämpningen? Vilka utfackningsväggar klarar bullerkraven vid en nybyggnation på Albyberget? Kan problematiken lösas enbart med väggarna eller krävs det ytterligare åtgärder? Är det ekonomiskt försvarbart att välja en tjockare vägg med hänsyn till u-värde istället för att maximera BOA? För att besvara dessa frågor har författarna genomfört laborationer, litteraturstudier samt tagit del av ett referensobjekt, akustikrapporter, energiberäkningsrapporter och kalkylböcker/offerter. Intervju med en person som besitter kunskap inom området buller/akustik har utförts och använts som kompletterande underlag. Resultatet ledde till att en standard träregelvägg på 395 mm som uppfyllde samtliga projektkrav som samtidigt var ekonomisk försvarbar med en kostnad på 1 391 kr/m2 rekommenderades till flerbostadshusen på Albyberget / AUCTORITAS Projektstyrning AB is working on obtaining contract documents for two new apartment buildings in an environment that is exposed to noise. One problem that has arisen is to find an infill wall that meets the requirements for noise and U-value, which at the same time is economically justifiable. The authors, on behalf of AUCTORITAS Projektstyrning AB, have examined 10 different infill walls with regard to noise reduction, U-value and price. The purpose of the work was to investigate the technical properties of the infill walls. The question that was addressed was the following: How does different materials affect the sound attenuation? Which infill walls can handle the noise requirements of a new construction on Albyberget? Can the problem be solved solely with the walls or does it require further action? Is it economically justifiable to choose a thicker wall with regard to u value instead of maximizing the living space? In order to answer these questions, the authors have carried out laboratory work, literature studies and also taken part in a reference object, acoustics reports, energy calculation reports and costing books/offers. An interview with a person with knowledge in the area of noise/acoustics have been completed and used as a complementary basis. The results led to a recommendation of a standard timber frame wall with a thickness of 395 mm, that met all of the project requirements and with a cost of 1 391 kr/m2 to be used in the buildings at Albyberget.
84

The In-between: Armature for Inhabitation

Rahman, Afrida Afroz 11 July 2023 (has links)
Flyovers, or grade separated bridges or roads, are a type of urban infrastructure that has been used to facilitate high-speed vehicular movement. This once-popular strategy of the west, despite being considered as a failure for sustainable urban growth, has been adopted in Bangladesh to combat traffic congestion in Dhaka that has a crippling effect on daily life of the citizens. As was anticipated by many urban planners and architects, these expensive structures did little to reduce traffic congestion, but created additional problems of noise and air pollution as well as reduced pedestrian mobility. More importantly, these flyovers created wasted void spaces underneath that are uncomfortable, devoid of human scale and act as physical and visual barriers that cause tears on the urban fabric. The objective of this thesis is to explore how architecture can unlock the potential of the unused spaces under the flyovers in Dhaka, by turning these linear leftover spaces into dignified public places that improves the daily lived experiences of the urban dwellers, by minimizing the disruptions caused by the flyover and by realizing the potential inherent in the robust structure of the flyover. This thesis examines a democratized way of building, where the role of architecture is to facilitate organic and heterogeneous growth, addition and modification to the flyover in order to bring the human scale back to the massive flyover structure through a reconciliation of top-down and bottom-up approaches. The architectural interventions respond to the site conditions, potentials and demands. The architectural outcome is based on the concepts of creating a threshold, architecture as armature and parasitic structures. / Master of Architecture / Flyovers, or grade separated bridges or roads, are a type of urban infrastructure that has been used to facilitate high-speed vehicular movement. This once-popular strategy of the west, despite being considered as a failure for sustainable urban growth, has been adopted in Bangladesh to combat traffic congestion in Dhaka that has a crippling effect on daily life of the citizens. As was anticipated by many urban planners and architects, these expensive structures did little to reduce traffic congestion, but created additional problems of noise and air pollution as well as reduced pedestrian mobility. More importantly, these flyovers created wasted empty spaces underneath that are uncomfortable and act as physical and visual barriers that cause tears on the urban fabric. The objective of this thesis is to explore how architecture can unlock the potential of the unused spaces under the flyovers in Dhaka, by turning these linear leftover spaces into dignified public places that improves the daily lived experiences of the urban dwellers, by minimizing the disruptions caused by the flyover and by realizing the potential inherent in the robust structure of the flyover. This thesis examines a democratized way of building, where the role of architecture is to facilitate organic and de-centralized growth, addition and modification to the flyover in order to bring the human scale back to the massive flyover structure through a reconciliation of top-down and bottom-up approaches. The architectural interventions respond to the site conditions, potentials and demands. The architectural outcome is based on the concepts of creating a threshold, architecture as armature and parasitic structures.
85

Estimating the Impact of Infill Housing on Reduction in Vehicle Miles Traveled

Ratto, Peyton Marie 01 June 2023 (has links) (PDF)
Vehicle miles traveled (VMT) and its relationship with the built environment has been extensively studied. Most notably, five D variables of the built environment including density, diversity, design, destination accessibility, and distance to transit are the key variables included in this research to explain VMT generation from housing developments. This thesis uses prior research that developed robust statistical models and findings to create a framework to estimate VMT reduction affected by infill housing developed using incentives provided by the state compared to a regional comparator. The regional comparator is typically a suburban single-family housing development in the region. The models recommended for future application of the framework are based on ease of finding the data on variables included in the model and statistical robustness. The application of the framework in the Central Coast and San Francisco Bay Area regions of California shows that infill prototypes developed can generate an 11-27% reduction in VMT per capita. The findings are specific to a synthetic household defined for this study. The research provides ways to apply this framework to other regions of the state along with ideas to consider for future work. These ideas include exploring the VMT reduction potential based on households with different income levels appropriate for the regions, future modeling efforts, and selection of existing models. The findings of this thesis support that the combination of the five D variables can help attribute to a larger VMT reduction than the VMT reduction caused by the change of a single variable. When destinations are clustered, and jobs are available at a reasonable distance to the residence, a significant reduction in VMT is more achievable. The results inform public agencies on which locations are ripe for devoting further resources for incentivizing housing development to reach climate and housing goals.
86

Potential Residential Buildings for Adaptive Reuse – Cincinnati’s CBD

Zushi, Keiichiro 14 July 2005 (has links)
No description available.
87

Mixed-Use Developments as Urban Infill and Development Strategy: An Optimization Problem?

Wuerzer, Thomas 30 October 2012 (has links)
No description available.
88

Impact of Infill Design on Mechanical Strength and Production Cost in Material Extrusion Based Additive Manufacturing

Baich, Liseli Jeanette January 2016 (has links)
No description available.
89

Response of Two-Way Reinforced Masonry Infill Walls under Blast Loading

Smith, Nicholas L. 04 1900 (has links)
<p>The increased public safety concerns to the consequences of deliberate and accidental explosions have led to the development of the Canadian (CSA S850- 12) and American (ASCE 59-11) blast standards. There is an urgent need to investigate and quantify the response of structural components under such extreme loading conditions. This is especially important for masonry components, where research has been limited due to the misconception that masonry (both reinforced and unreinforced) is an inadequate material for blast hardening applications. The standards allow the use of experimental testing or dynamic analysis in order to determine peak responses and evaluate them in terms of the code prescribed performance limits and accompanying levels of damage. The current study investigates the response of non-integral and non-participating infill walls designed to undergo two-way out-of-plane response and detailed to fail in flexure under static loading conditions. Through experimental blast testing and dynamic model validation of reduced-scale walls under a range of design-basis threat (DBT) levels, this study shows that reinforced masonry is a viable alternative for blast protection. However, the current flexural-based code requirements, thought to be conservative, may be inadequate at loads of higher impulse where shear damage is prevalent. This study also shows the influence that changing the boundary configuration and level of reinforcement has on the peak response, where the performance limits of the current codes makes no provisions for these parameters.</p> / Master of Applied Science (MASc)
90

The Millionaire Programme

Åström, Axel January 2023 (has links)
Can the single family suburb survive into a post fossil future? This project explores the financial and ecological conditions of suburbia and how this will shape its future. The conclusion is that in its current form there is little chance for it to survive, in fact it is already being deconstructed.With the aim to reduce sprawl and protect the commons, while trying to maintain some of the calmer and softer properties that makes the suburbs so attractive for many people.The proposal is therefore to place rowhouses as infill between the current housing stock, creating a more dense city which has a higher capability to sustain itself. This is to be supplemented by an urban strategy that provides community centres and retail spaces where needed (along with public transport and paths for walking/biking).The hope here is to create neighbourhoods that can sustain under the 15-minute city model, while also giving people the possibility to live way more ecologically than previously possible, without having to bulldoze or drastically reshape it.But most of all its meant to spark a discussion about how suburban neighbourhoods can transition into a fossil free future, can we get them there by their own volition and on its own terms or are the suburban life doomed to be left behind?

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