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Simbaqueba MS Thesis Defense

THE UNIVERSITY OF CONNECTICUT

Civil & Environmental Engineering 

 

JORGE LUIS SIMBAQUEBA RUIZ, P.E., LEED GREEN ASSOC.

Masters Thesis Defense

Department of Civil & Environmental Engineering

University of Connecticut

 

2:00 P.M. – WEDNESDAY, DECEMBER 19, 2018

CAST 306

Advisory Committee:

Dr. Norman Garrick (Major Advisor)

Dr. Atkinson-Palombo (Major Advisor)

Dr. John Ivan (Associate Advisor)

WHAT DOES WALK SCORE® REALLY MEASURE?

 

In recent years there has been an increase in the research of the concepts of accessibility, land use, travel behavior and walkability. These topics have become critical to planners, engineers and policymakers as they work to make correct decisions in the development and redevelopment of urban places and their related transportation infrastructure. More importantly, research has shown that street network design and street design characteristics have been found to be significantly associated with outcomes such as travel behavior, road safety, physical activity, and public health.

In 2007, the technology incubator Front Seat began development of the Walk Score® (WS), a metric created to help people evaluate the walkability of specific locations. With a simple street address search, you get a map with nearby amenities and a walkability score. The Walk Score® (WS) algorithm works by identifying the closest amenities (for example, grocery stores, banks, restaurants, and schools) and awarding points based on the distance to them from a given location. Scores have a range between 0 and 100, with 100 being the best. In 2011, the Walk Score® (WS) founders and advisory board modified the algorithm to better account for pedestrian friendliness by adding block length and intersection density data into the model to represent roadway characteristics (walkscore.com). Although this version was originally named Street Smart Walk Score® (SSWS), the name never made it to into the public sphere.  However, the algorithm was accepted and incorporated into what is now used for scores on the Walk Score® web service.

Modelers attempting to quantify accessibility often focus on two components: a transportation element (or resistance factor) and an activity element (or attraction factor). The transportation element often considers variables such as infrastructure, topography, route directness, as well as distance, travel time, or cost. Activity factors are measured from objective variables such as destination locations, parking availability, land-use density, land-use mix, and subjective variables such as the perceived quality of products at destinations. It is generally believed that Walk Score® (WS) and Street Smart Walk Score® (SSWS) account for both the land use and the street network elements of accessibility measures.  However, the extent to which these metrics accurately represent these variables has not been fully evaluated by research. The goal of this thesis is to determine if Walk Score® (WS) and Street Smart Walk Score® (SSWS) are true measures of accessibility in fully representing both transportation and activity. In this body of work, Walk Score® (WS) and Street Smart Walk Score® (SSWS) are analyzed to understand if they adequately account for street network density, street network connectivity and street design characteristics – all of which are key aspects of the transportation element of accessibility.

Seminar 18/12/03

Speaker: 1. Emily Hultquist, AICP, Director of Policy and Planning/Community Development at CRCOG – Hartford, CT; 2. Shawna Kitzman, AICP, Senior Planner, Fitzgerald & Halliday, Inc., Hartford, CT.

Title: Metro Hartford TOD Project

Location: EII 322

Time: Monday, December 03, 2018 12:20 – 1:10 PM

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Yaguang Du PhD Defense

University of Connecticut

Department of Civil and Environmental Engineering

Environmental Engineering Program

Yaguang Du

 

PhD Thesis DEFENSE

Department of Civil & Environmental Engineering

Environmental Engineering Program

University of Connecticut

 

10:00 A.M. – THURSDAY, NOVEMBER 29, 2018

CAST 306

Advisor Committee:

Maria Chrysochoou (Major Advisor)

Amvrossios C. Bagtzoglou (Associate Advisor)

Baikun Li (Associate Advisor)

Timothy Vadas (Associate Advisor)

Liyuan Chai (Associate Advisor)

“An investigation of the geochemical properties and treatment of soda ash Chromite Ore Processing Residue”

 

Abstract:  In recent years, the common lime-based roasting process of chromite ore that is used to extract chromium is being replaced by alternative processes that produce less waste. Chromite Ore Processing Residue (COPR) contains high concentrations of hexavalent chromium (Cr(VI)), a human carcinogen, and is a hazardous waste that requires intensive treatment prior to disposal. China has banned the lime roasting process since 2013 and an alternative process using soda ash as roasting and complexing agent has replaced it in the larger factories. The process still produces COPR with residual Cr(VI), albeit in lower amounts. Although much is known about the properties and treatment of lime-based COPR, there are no studies in the literature on soda ash derived COPR. Accordingly, this research constitutes the first comprehensive assessment of soda ash COPR in terms of: a) chemistry, mineralogy and leaching characteristics; b) speciation of Cr(VI) in the solid; c) treatment of residual Cr(VI) using different reducing agents. The COPR sampled from a large factory in China contained 8,500 mg/kg of Cr(VI), indicating poor recovery during the leaching process. Preliminary tests indicated that approximately 90% of the Cr(VI) is water soluble, while the remaining 10% is more tightly held within the matrix and requires lowering the pH from 12.5 to 8 for release. Accordingly, all studies will be performed on two distinct COPR fractions: “original” COPR, with the material tested as-is, and “column leached” COPR, which has been subjected to DI water leaching to remove all water-soluble Cr(VI) prior to further studies. The proposed research is divided into three parts: The first part is a leaching and modeling study of the two COPR types, studying the leaching of major and trace elements as a function of pH. The second part utilized microstructural spectroscopy techniques (micro-X-ray Fluorescence, Absorption and Diffraction) to study the mineral hosts of Cr(VI), information used to optimize treatment. Finally, the third part evaluated the reduction of residual Cr(VI) in COPR using calcium polysulfide, nano-scale zerovalent iron stabilized with gree tea extract (GT-nZVI), and pyrolysis remediation with miscanthus mixture.

Seminar 18/11/16

Speaker: Prof. Casey Brown, University of Massachusetts at Amherst

Title: Freshwater Resilience by Design: Water investment strategies for a changing and uncertain future

Location: IPB 203

Time: November 16th 2018 1:00 PM – 2:00 PM

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Vandenberg Phd Dissertation

THE UNIVERSITY OF CONNECTICUT

Civil & Environmental Engineering 

 

AILEEN VANDENBERG, B.S., B.A., M.S.

 

Ph.D. Dissertation

Department of Civil and Environmental Engineering

University of Connecticut

 

10:00 AM – Thursday, November 15, 2018

CAST 306

 

Advisory Committee:

Dr. Kay Wille (Major Advisor)

Dr. Nicolas Roussel (Major Co-Advisor)

Dr. Hela Bessaies-Bey (Associate Advisor)

Dr. Michael Accorsi (Associate Advisor)

Investigating High Energy Mixing in Cement-Based Materials

 

ABSTRACT

One of the current challenges to nano-engineering cementitious composite materials is obtaining properly dispersed nano-sized particles in the cementitious composite matrix. Properly dispersed nanoparticles can lead to an improved particle packing density, a key parameter to improving the mechanical, chemical, and sustainable properties of the cementitious composite. Broadening the particle size distributions of cementitious materials, such as ultra-high performance concrete (UHPC), to include additional nano-sized particles is a challenge that requires a better understanding of how they self-assemble in the cementitious matrix. Thus, the purpose of this research is to investigate the role mixing plays in multi-scale, multi-phase self-assembling cement-based material systems. This is achieved through three objectives. The first objective is to investigate resonant acoustic mixing, a mixing method not common to the concrete industry, and its ability to act as a high-intensive mixer. The second objective is to consider how using resonant acoustic mixing affects the assemblage of UHPC with carbon nanofiber inclusions and cement paste with carbon nanoplatelet inclusions. The third objective is to understand the origins of high-shear mixing and how it influences the development of cement hydration.  To achieve these three objectives a systematic analysis is carried out that includes quantifying the mixing energy demand; analyzing surface characteristics through scanning electron microscopy, inverse gas chromatography, dynamic light scattering, and mercury intrusion porosity; and applying rheological theory to connect macroscopic properties to the fundamental properties of the materials. The results show that mixing is a very important parameter to multi-scale, multi-phase self-assembling cement-based materials and should be considered more in concrete research.

Seminar 18/11/12

Speaker: Professor Peter C. Baldwin, Department of History, College of Liberal Arts & Sciences University of Connecticut

Title: Dependence, Damage, and Displacement: Unintended Consequences of Technological Change.

Location: EII 322

Time:  Monday, November 12, 2018, 12:20 – 1:10 PM

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Seminar 18/11/05

Speaker: Jingyue Zhang & Amit Mondal, Transportation Graduate Students

Titles: 1. a novel divide and combine based approach to estimating mixture markov model for large categorical time series data: an application to study of clusters using multiyear travel survey data
2. synthesizing household and person-level attributes jointly for individual geographies using hidden markov model

Location: EII 322

Time: Monday 11/05/18 @ 12:20PM

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2018-19 AEESP Foundation Distinguished Lecturer Dr. Lutgarde Raskin

Lecture Topic: Converting urban organic waste streams into sustainable resources with novel anaerobic bioprocesses.

Speaker: Dr. Lutgarde Raskin, Ph.D., Altarum/ERIM Russell O’Neal Professor of Engineering, Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI, USA

Location: Linsly-Chittenden Hall, 63 High Street, New Haven, CT

Time: 4:00-5:00 pm. October 22, 2018.

 

Organizers: Yale University, University of Connecticut, Central Connecticut State University and University of New Haven.

 

Abstract: “Anaerobic digestion based technologies have great potential for converting the enormous amounts of organic waste generated in urban environments into valuable resources. Yet few urban organic waste streams are currently treated by anaerobic bioprocesses, suggesting that new approaches are needed. This presentation will show the development of novel anaerobic bioprocesses for resource recovery from urban organic waste streams by applying knowledge of microbiomes from habitats as diverse as arctic sediments and the gastrointestinal tract of ruminant animals and sustainable technology design practices. Examples will include: (i) Biofilm-enhanced anaerobic membrane bioreactor designs to treat low-strength urban wastewater at low temperatures to achieve high quality water, reduced greenhouse gas emissions, and net positive energy production, and (ii) Dynamic anaerobic membrane bioreactor designs inspired by the physiology and microbiome of the rumen (stomach of ruminant animals) to overcome slow hydrolysis of urban organic waste streams with high lignocellulosic content to produce short-chain carboxylic acids that can be used for the production of biomethane and other bioproducts. While the role of microbiomes in developing these anaerobic bioprocesses will receive most attention, the presentation will also show how the advancement of these technologies is driven by life cycle cost and environmental assessments to enable financially viable, environmentally sustainable waste management.”

About Professor Raskin: Lutgarde (Lut) Raskin is the Altarum/ERIM Russell O’Neal Professor of Engineering at the University of Michigan. She is a pioneer in molecular microbial ecology applied to water quality control and anaerobic bioprocesses. Her research focuses on managing the microbiome of drinking water systems and developing anaerobic bioprocesses for resource recovery from waste streams. She has published about 130 peer-reviewed journal papers and 350 conference proceedings papers and abstracts. Dr. Raskin is passionate about graduate education and has mentored approximately 15 postdocs and 90 graduate students, including 25 PhD students. She received BS and MS degrees from the KU Leuven in Belgium and a PhD degree from the University of Illinois at Urbana-Champaign. Prior to joining the faculty at the University of Michigan in 2005, she was a faculty member at the University of Illinois at Urbana-Champaign. She is an elected Fellow of the American Academy of Microbiology and the Water Environment Federation. Past honors include the University of Michigan Rackham Distinguished Graduate Mentor Award, the International Society for Microbial Ecology-International Water Association BioCluster Award, the Association of Environmental Engineering and Science Professors Frontier Award in Research, the American Society of Civil Engineers Walter L. Huber Civil Engineering Research Prize, the Water Research Foundation Paul L. Busch Award, and a U.S. National Science Foundation CAREER Award. She is an Associate Editor for Environmental Science & Technology and serves on the Board of Directors of the Association of Environmental Engineering and Science Professors.

Seminar 18/10/22

Speaker: Scott Mullen, Director of Expansion, Northeast at Lime

Title: Lime: The Promise and Potential of Dockless Mobility

Location: EII 322

Time: Monday 10/22/18 @ 12:20PM

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Chi Epsilon Review Sessions – 2

Topic: Fluid Mechanics

Instructor: Dr. Zoi Dokou

Location: CAST201

Time: Monday, October 15th 6-8PM