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Civil and Environmental Engineering - Master's degree

Mostrando recursos 1 - 20 de 2.699

  1. Incorporating direct demand modeling and improved modal choice into freight commodity movement models.

    Robillard, Paul
    Massachusetts Institute of Technology. Dept. of Civil Engineering. Thesis. 1974. M.S.

  2. Design and deploy : co-creative public transport planning using a web -based stakeholder engagement tool

    Zheng, Xin, S. M. Massachusetts Institute of Technology
    Using new technologies, such as web-based applications and online map visualizations, to help public engagement for public transit campaigns is an emerging trend in the urban planning field. Scenario simulations and map-based visualizations to show accessibility or travel time impacts can provide users insights into the possible results of new transportation projects. CoAXs (Collaborative Accessibility-based Stakeholder Engagement platform) is a web-based application that has been implemented in experimental public engagement exercises in three cities in the United States to test its potential for facilitating the public engagement process around public transit advocacy. In 2016 and 2017, two types of experiments...

  3. Learning Structures : fusing deconvolution-based seismic interferometry with Bayesian inference for structural health assessment

    Uzun, Murat
    Monitoring vibration responses of civil structures is crucial to the assessment of their health status and reliability against natural hazards. In this study, we present a two-step computational methodology for structural identification and damage detection via fusing the concepts of seismic interferometry and Bayesian inference. Firstly, a deconvolution-based seismic interferometry approach is employed to obtain the wave-forms that represent the impulse response functions (IRFs) with respect to a reference excitation source. Using the deconvolved waveforms, key structural characteristics that correspond to the current state of the structure (e.g., shear wave velocity) can be extracted. Changes in these features can be...

  4. Regional summer climate variability and change over North America in the 20th Century

    Nikiel, Catherine Anna
    The climate of North America reflects the natural variability of global atmospheric circulation, and is impacted by two primary anthropogenic forcings: increasing concentrations of greenhouse gases (GHG) and Land Use/Land Cover Change (LULC). The objective of this thesis is to quantify the relative impacts that these two anthropogenic forcings have had on summer climate over North America in the course of the 20th century. Simulations are conducted spanning the full 20th century over the United States to the east of the Rocky Mountains, and analysis of model simulations and observations is carried out with a focus on the Midwestern United...

  5. Value of information in dispatching shared autonomous mobility-on-demand systems : a simulation framework

    Wen, Jian, S. M. Massachusetts Institute of Technology
    The concept of shared mobility-on-demand (MoD) systems describes an innovative mode of transportation in which rides are tailored as per the immediate requests in a shared manner. Convenience of hailing, ease of transactions, and economic efficiency of crowd-sourcing the rides have made these services very attractive today. It is anticipated that autonomous vehicle (AV) technology may further improve the economics of such services by reducing the operational costs. The design and operation of such an shared autonomous mobility-on-demand (AMoD) system is therefore an important research direction that requires significant investigation. This thesis mainly addresses three issues revolving around the dispatching...

  6. Design and performance of Thomas Telford's Bonar Bridge and Mythe Bridge

    Lane, Ellen (Ellen Philippa)
    This paper assesses two cast-iron arch bridges of Thomas Telford (1757-1834) - Bonar Bridge (1810-12) and Mythe Bridge (1824-26) - to draw a broader conclusion about his career in bridge building. The bridges are introduced and Telford's design influences are investigated. While Telford was influenced by theory through the advice of his contemporaries, he was more heavily influenced by experience, especially design precedents, and most of all by his own judgment, which placed great emphasis on both practicality and aesthetics. The structural performance of the two bridges is assessed and compared. The cast-iron arch's ability to resist vertical loading is...

  7. Investigating the effect of variability in biomass burning emissions inventories on GEOS-Chem modeled trace gas and aerosol concentrations

    Su, Flora K. (Flora Kathleen)
    Over the past century, global wildfire activity has intensified due to increasing mean temperatures. However, emissions inventories used for modeling the impact of fires on air quality and climate exhibit several discrepancies in emissions estimates, largely due to the different types of satellite products used for identifying fires and measuring burned area, as well as differences in emission factors describing the vegetative fuels burned. Using the GEOS-Chem v1 1-01 chemical transport model, we studied how differences in emissions estimates between two commonly-used global biomass burning inventories, the Global Fire Emissions Database (GFED4) and the Fire INventory from NCAR (FINNy 1),...

  8. The phase separation inlet for droplets, ice residuals, and interstitial aerosols

    Koolik, Libby (Libby P.)
    A new inlet for studying the composition of mixed-phase clouds - the phaSe seParation Inlet for Droplets icE residuals and inteRstitial aerosols (SPIDER) - is described. SPIDER combines an omni-directional inlet, a Large-Pumped Counterflow Virtual Impactor (L-PCVI), a flow tube as evaporation chamber, and a Pumped Counterflow Virtual Impactor (PCVI) to separate droplets, ice crystals, and interstitial aerosols for simultaneous sampling. Verification tests of each individual component of SPIDER were positive, as was the result of investigating that the components work together as a whole setup without flow blockage or choking. SPIDER was installed at Mt. Washington Observatory (MWO), a...

  9. Adapting a hazards-risk model to water scarcity in rural India : Aurangabad case study

    Midstokke, Paige K
    The objective of this project is to improve the responsiveness of District Planning to rural water scarcity in India. Through engagements with the Groundwater Survey Development Agency, and Maharashtra State Government Water Supply and Sanitation Department, we selected Aurangabad District to conduct field visits and develop a model that can spatially represent risk of villages to water scarcity. Within Aurangabad District, Vaijapur block was selected as a case study due to its drought effects and high water tanker usage in the past five years. This thesis develops a disaster risk metric for water scarcity, using an analysis of potential hazards,...

  10. Accelerating bus electrification : enabling a sustainable transition to low carbon transportation systems

    Blynn, Kelly (Kelly Mavis)
    With growing agreement that credible pathways to zero carbon electricity exist, many support the notion that widespread electrification of the transportation sector will be an essential strategy for meeting scientifically-based midcentury climate goals. While transit buses have a relatively small impact on greenhouse gas emissions, they have a larger impact on urban air quality, have commercially available in-service electric models, and have historically commercialized clean technologies that enabled deployment in the rest of the heavy duty vehicle sector. This thesis seeks to understand what factors hinder or enable transit agencies to go beyond initial pilots to largely or wholly electrify...

  11. The analysis of a building frame by mechanical methods

    Mittet, Holger Peter
    by Holger Peter Mittet.

  12. Photochemical transformation of particulate organic carbon and its impact on mercury cycling in aqueous systems

    Gelfond, Claudia E. (Claudia Elisabeth)
    Mercury (Hg) is a global pollutant with high toxicity that accumulates in biota and biomagnifies, posing a risk to organisms throughout the food chain. Mercury is known to strongly associate with natural organic matter (NOM), which, in turn, affects its speciation, solubility, mobility and toxicity. Numerous studies have examined Hg coordination with dissolved organic carbon (DOC), an important aqueous constituent that alters the reactivity and fate of Hg primarily through complexation with carboxyl and reduced sulfur (e.g. sulfhydryl) groups. However, less is understood of Hg reactions with particulate organic matter (POM), an important reservoir of NOM found within soils, sediments,...

  13. Determinants of residential location demand : implications for transportation policy

    Weisbrod, Glen E. (Glen Elliot)
    by Glen E. Weisbrod.

  14. Stochastic response of tall buildings with auxiliary dampers

    Tazir, Zahra-El-Hayat
    by Zahra-El-Hayat Tazir.

  15. National co-ordination of housing

    Hull, Cordell William
    by Cordell William Hull.

  16. Automobile regulations in China examined from a behavioral perspective

    Wang, Shenhao
    Automobile growth has created severe problems such as traffic congestion, air pollution, and carbon emission worldwide. To address these problems, Chinese local governments implemented a series of automobile regulations to slow down auto growth. They set up a yearly quota of license plates and require potential car buyers to obtain a license plate before buying an automobile. Local governments end up with three modes of allocating the scarce license plates: only lotteries, only auctions, and a mix of lotteries and auctions. The main debate is the tradeoff between the efficiency represented by auctions and the equity represented by lotteries. By...

  17. Automobile regulations in China examined from a behavioral perspective

    Wang, Shenhao
    Automobile growth has created severe problems such as traffic congestion, air pollution, and carbon emission worldwide. To address these problems, Chinese local governments implemented a series of automobile regulations to slow down auto growth. They set up a yearly quota of license plates and require potential car buyers to obtain a license plate before buying an automobile. Local governments end up with three modes of allocating the scarce license plates: only lotteries, only auctions, and a mix of lotteries and auctions. The main debate is the tradeoff between the efficiency represented by auctions and the equity represented by lotteries. By...

  18. Demonstrating the feasibility of polyethylene passive samplers for quantitative assessment of volatile organic compounds in soil

    Saparbaiuly, Galym
    A quantitative assessment of the nature and extent of volatile organic compounds (VOCs) in soil vapors is a valuable tool, as these chemicals are pervasive and a health concern at many contaminated sites. Motivated by the successful use of polyethylene (PE) passive samplers in sediments, this research focused on demonstrating the feasibility of PE samplers to accurately assess volatile organic compounds in soil vapors. Experimental values of PE-water partitioning coefficients (Kpew) for benzene, toluene, ethyl benzene, and ortho-xylene (BTEX) were determined. A benchtop experiment in a controlled environment was performed, which consisted of a jar of sand with known amounts...

  19. Demonstrating the feasibility of polyethylene passive samplers for quantitative assessment of volatile organic compounds in soil

    Saparbaiuly, Galym
    A quantitative assessment of the nature and extent of volatile organic compounds (VOCs) in soil vapors is a valuable tool, as these chemicals are pervasive and a health concern at many contaminated sites. Motivated by the successful use of polyethylene (PE) passive samplers in sediments, this research focused on demonstrating the feasibility of PE samplers to accurately assess volatile organic compounds in soil vapors. Experimental values of PE-water partitioning coefficients (Kpew) for benzene, toluene, ethyl benzene, and ortho-xylene (BTEX) were determined. A benchtop experiment in a controlled environment was performed, which consisted of a jar of sand with known amounts...

  20. Multi-objective optimization of vertically mixed lateral systems

    Haseeb, Nablul
    This thesis explores the advantages of using vertically mixed lateral systems in rectangular buildings consisting of uniform bay dimensions. Three forms of lateral systems i.e. moment frames, steel cross bracings and concrete shear walls are utilized at varying elevations of the building to determine an optimal set of results. Besides analyzing structural optimality, the MATLAB algorithm developed as a part of this research paper also evaluates each system for its overall structural weight, material cost and embodied carbon. By taking a multi-objective optimization approach at the design of lateral load-resisting systems in buildings, this research devises a practical tool that...

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