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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.
111

Design rýpadla / Design of excavator

Brza, Lukáš January 2009 (has links)
The design of the excavator follows requirements of machines for demolition work. The excavator is equipped with an innovative type of under carriage, which not only increases mobility over the demolition sites but also the visibility from the driver’s cabin. The components of the excavator, that improve the demolition work, are special types of tracks, suspensions and articulated steering. Tracks can change their shape to increase the stability and also to adapt to the diff erent types of ground. The suspensions with tracks are able to adapt to the terrain thereby they lighten the asperity. Suspension can also tilt or even raise the excavator and thereby increase the angle of visibility from the cabin. This function is necessary mainly when taking down higher constructions. Articulated steering is a new function that has never been used for excavators. This steering was chosen due to fl exible movement over demolition sites. The main aim of the project is to create a new design of the excavator, but more importantly to distinguish the excavator from the excavators already on the market, with regards to its esthetics and under carriage innovation.
112

Rekonstrukce železniční stanice Vsetín / Upgrading of Vsetín Railway Station

Maixner, Pavel January 2016 (has links)
The aim of the diploma thesis is design of the Vsetín railway station reconstruction according to the current operation and the requirements for persons with reduced mobility. The two new double face island platforms with the height of 550 mm above the top of rail is designed. Further, the speed in passing running lines and also the curves in front of Polanka throat of the station is increased.
113

Slab track systems for high-speed railways.

Michas, Georgios January 2012 (has links)
In the last 40 years an increase in train speed and axle load around the world and other challenges in the conventional ballasted track system gave birth to ballastless railway track system. This study examines in depth the various slab track systems that are being used today. Their design characteristics as well as the various requirements for efficient use are thoroughly explained. At least 34 different ballastless systems have been recorded in many railway networks throughout the world. The most significant slab track systems are analysed in detail and compared. Slab track designs have significant advantages comparing to ballasted tracks. The most significant are the high stability of the track, the almost non-existent need for maintenance, the long life cycle (60 years) and the reduced weight and height of the track. Their disadvantages against the ballasted tracks are mainly summarized in their higher construction costs. The Finite Element package ABAQUS/CAE is used to model a 3-D slab track design under static traffic loading. The results suggest that slab tracks have profoundly better stability and durability comparing to ballasted tracks mainly due to their higher stiffness and strength. The author underlines the need for further studies to undoubtedly prove the claimed advantages of slab track systems as well as to improve the costs associated with construction.
114

Stopy v současném umění / Tracks in contemporary art

Houšková, Aneta January 2020 (has links)
The diploma thesis as a whole deals with the topic of tracks in contemporary art. It is divided into three parts. Theoretical, didactic and practical part. In the theoretical part, I first define what a track means to me and I apply this definition when searching for tracks in the works of contemporary artists. The theoretical part of the work includes an interview with Patrik Proška, an artist creating some of his works in public space. In the didactic art project, created for high school students, the topic of tracks is viewed somewhat more freely. The main goal of the thematic unit is to lead students to think about tracks through their own artistic activity. Based on the experience gained, they should be able to think about the transience of the tracks, the meaning of our legacy and the consequences of our existence. I especially focus on the art area related to land arts and street art or graffiti. The practical part is the result of my reasoning about the tracks left in public space. I established my reasoning on the knowledge gained in the theoretical part. The result is a set of author's books that document my thoughts on the tracks found or created. I focused my attention mainly on the human desire to leave their tracks in the public space. KEY WORDS track, public space, art, land art,...
115

Video-based assessment of cyclist-tram track interactions in wet road conditions

Gildea, Kevin, Mercadal-Baudart, Clara, Caulfield, Brian, Simms, Ciaran 02 January 2023 (has links)
Cyclist underreporting of lower severity and single cyclist collisions to police results in the underestimation of the societal costs of lower severity and single cyclist collisions [1], [2]. Prevention strategies for these types of collisions are becoming a popular area of research, and video-based approaches have obvious potential for these cases, allowing for detailed analyses of underreported lower severity and single cyclist falls. Video-based studies have been used to investigate site-specific cyclist safety issues such as railway crossings [3 ]. They have also been used for near-collision or near-miss incidents and Surrogate Measures of Safety (SMoS), e.g., [4]. A recent Irish study has identified the most common collision configurations and factors with the inclusion of unreported cases [5]. Findings indicate that falls involving interactions with light rail tram tracks are common in Dublin; they were the most common infrastructural collision partner in this study and a contributing factor in 23% of single cyclist collisions (ibid.), supplementing international findings [6], [7]. Furthermore, along with increasing popularity of cycling, many new light rail systems are being implemented across Europe as part of a broader move towards sustainable transport [8]. Accordingly, further investigation is required to avoid potential conflicts. Therefore, this study aims to use video-based assessment to correlate fall risk with trajectories and crossing angles. [From: Introductiojn]
116

Conductive Tracks in Carbon Implanted Titania Nanotubes: Atomic-Scale Insights from Experimentally Based Ab Initio Molecular Dynamics Modeling

Holm, Alexander, Kupferer, Astrid, Mändl, Stephan, Lotnyk, Andriy, Mayr, Stefan G. 09 November 2023 (has links)
Ion implantation of titania nanotubes is a highly versatile approach for tailoring structural and electrical properties. While recently self-organized nanoscale compositional patterning has been reported, the atomistic foundations and impact on electronic structure are not established at this point. To study these aspects, ab initio molecular dynamic simulations based on atomic compositions in C implanted titania nanotubes according to elastic recoil detection analysis are employed. Consistent with experimental data, carbon accumulates in chainlike precipitates, which are favorable for enhancing conductivity, as revealed by density-functional theory electronic ground states calculations are demonstrated.
117

Dynamic Tuning of Hydraulic Engine Mount Using Multiple Inertia Tracks

Barszcz, Benjamin Daniel 24 August 2010 (has links)
No description available.
118

Hållbara spårvägar / Sustainable Tramway Tracks

Dahlström, Johanna, Hansen, Licette, Hartel, Ellen, Larsson, Francesca, Pettersson, Hanna January 2019 (has links)
The Swedish city of Uppsala is growing and will be expanded. To manage the increase in traffic, a tramway is being planned. It is vital to make the construction and the tramway tracks sustainable. This is explored to study carbon dioxide emissions related to tramway track materials as well as their wear and service life. This project investigates sustainability, the tramway track constituents, rail steel, the rails' wear, rail surface treatments that could minimize wear and increase service life, materials surrounding the rails, and the production of the most used materials in tramway tracks. A literature study is conducted to compare different options for materials and treatments. The municipality of Uppsala's climate goals, technical standards and regulations, articles and studies about the mentioned topics, amongst other sources, are considered and compared. The results include a rough estimation of the material consumption and carbon dioxide emissions. Asphalt tracks have the lowest emissions of the different surrounding material options. The steel consumption and carbon dioxide emissions for the vignole rails are less than for grooved rails and the concrete consumption for grass tracks is slightly less compared to edilon tracks. It is also possible to switch from regular perlitic rail steel to bainitic rail steel when needed. Laser hardening, UNSM, and thermal plasma hardening decrease the rails' wear (rates) considering increased surface hardness. / Uppsala är en växande stad och därför ska Södra staden byggas ut. Spårvagnstrafik planeras för att hantera den kommande trafikbelastning. Det är viktigt att göra konstruktionen av spårvägen till spårvagnen så hållbar och miljövänlig som möjligt. Detta utreds i denna rapport för att undersöka koldioxidutsläpp från spårvägens material samt dess slitage och livslängd. Rapporten undersöker hållbarhet, hur spårvägarna ser ut och dess olika delar, rälstål, rälernas slitage, ytbehandlingar till rälarna som kan minimera slitage och öka livslängden, samt tillverkningen av de mest förekommande materialen i spårvagnars spårvägar. En litteraturstudie genomförs för att jämföra olika materialvals- och behandlingsalternativ. Uppsala kommuns klimatmål, tekniska standarder och regelverk, artiklar och studier om de nämnda ämnena, bland andra resurser, används och jämförs. Studiens resultat inkluderar en grov uppskattning av materialåtgången och koldioxidutsläpp. Det blir minst koldioxidutsläpp från asfaltsspår när det gäller de omgivande materialen. Stålåtgången och koldioxidutsläppen för vignolräler är mindre än för gaturäler och betongåtgången blir lite mindre för grässpår jämfört med edilonspår. Det är även möjligt att byta från vanligt perlitiskt rälstål till bainitiskt rälstål vid behov. Laserhärdning, UNSM och termisk plasma härdning minskar rälernas slitage med avseende på framförallt ökningar av ythårdhet.
119

How Disassociating the Past Reassociates the Present: Distilling the Magic out of Magic Realism in Susan Power’s The Grass Dancer

Lewis, Abby N. 01 May 2017 (has links)
American Indian author Susan Power’s novel The Grass Dancer is often categorized as magical realism, yet Power has stated the novel is a representation of her reality and that it is not a magical realist text. The term magical realism was first applied to the work of Latin American authors such as Gabriel García Márquez whose writing depicts magical events in a matter-of-fact narrative tone. It has since expanded to include other cultures. The question is whether it is a term that can readily be applied to the literary work of all cultures. The closest Wendy B. Faris, one of the most prominent experts on magical realism, comes to discussing the term in relation to the work of American Indian authors is by simply acknowledging Ojibwe writer Louise Erdrich’s label as a magical realist author. In order to aid Power in her rejection of the association, I delve into both her Dakota heritage and her life through the lens of biographical criticism in order to obtain a working image of her reality. By locating and examining the seeds of truth in her fiction, I explain the magical qualities of her novel in a rational and logical manner.
120

Using ship tracks to characterize the effects of haze on cloud properties

Segrin, Matthew S. 14 June 2006 (has links)
1-km MODIS observations of ship tracks off the west coast of the U.S. are used to characterize changes in cloud visible optical depths, cloud droplet radii, cloud cover fraction, and column cloud liquid water amount as low-level marine clouds respond to particle pollution from underlying ships. This study re-examines the finding of earlier studies based on Advanced Very High Resolution Radiometer (AVHRR) observations showing that when restricted to pixels overcast by low-level, single-layered cloud systems, the polluted clouds in the ship tracks had on average ~20% less liquid water than the nearby uncontaminated clouds. This study uses Moderate Imaging Spectroradiometer (MODIS) observations from the Terra and Aqua satellites and takes advantage of the 1.6 and 2.1-µm channels in addition to the 3.7-µm channel available on AVHRR to derive droplet effective radii. The additional channels allow for different and presumably more comprehensive analyses of the cloud properties. In addition, this study uses a retrieval scheme that accounts for the effects of partial cloudiness within the 1-km pixels on the retrieved cloud properties. An improved automated track finding scheme that allows for the selection of unpolluted clouds to be closer to the clouds identified as being polluted is also employed in this study. When restricted to overcast pixels, as was done in earlier studies, results from the Terra and Aqua MODIS observations indicate that cloud droplet effective radii are significantly smaller and cloud optical depths significantly larger for polluted pixels than for unpolluted pixels. Cloud top height does not change when clouds become polluted but cloud liquid water path decreases slightly but significantly. The decrease in cloud liquid water obtained with the MODIS observations was at most ~10%, much less than the 20% obtained with the AVHRR observations. This decrease, however, depended on the wavelength used to derive the droplet effective radii. Also, the clouds that were most sensitive to pollution were those with small optical depths and large droplet effective radii. / Graduation date: 2007

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