Engineering Commons^™

Propositions For A Resilient, Post-Covid-19 Future For The Aec Industry, Hala Nassereddine, Kyung Wook Seo, Zofia K. Rybkowski, Christian Schranz, Harald Urban

Civil Engineering Faculty Publications

The coronavirus outbreak has challenged and continues to challenge every aspect of the supply chain within the AEC industry, forcing stakeholders to cope with increasing uncertainties and continuous change. The notion of resilience is especially salient now. While the need for the AEC industry to focus on resilience has been highlighted in recent articles, there is a need for a comprehensive discussion on what resilience means for the AEC industry and how companies can create built-in resilience. This paper takes the form of a high-level overview of where the industry is headed and aims to establish eleven propositions for a …

Gas Component Transport Across The Soil-Atmosphere Interface For Gases Of Different Density: Experiments And Modeling, L. M. Bahlmann, K. M. Smits, K. Heck, E. Coltman, R. Helmig, I. Neuweiler

Civil Engineering Faculty Publications

We investigate the influence of near-surface wind conditions on subsurface gas transport and on soil-atmosphere gas exchange for gases of different density. Results of a sand tank experiment are supported by a numerical investigation with a fully coupled porous medium-free flow model, which accounts for wind turbulence. The experiment consists of a two-dimensional bench-scale soil tank containing homogeneous sand and an overlying wind tunnel. A point source was installed at the bottom of the tank. Gas concentrations were measured at multiple horizontal and vertical locations. Tested conditions include four wind velocities (0.2/1.0/2.0/2.7 m/s), three different gases (helium: light, nitrogen: neutral, …

The Effect Of The Top Soil Layer On Moisture And Evaporation Dynamics, Zhen Li, Jan Vanderborght, Kathleen M. Smits

Civil Engineering Faculty Publications

Understanding the effect of the top soil layer on surface evaporation and water distribution is critical to modeling hydrological systems. However, the dependency of near-surface soil moisture and fluxes on layering characteristics remains unclear. To address this uncertainty, we investigate how the arrangement of soil horizons affects the evaporation and soil moisture, specifically, the near-surface soil moisture, through the combination of numerical simulations and evaporation experiments. The characteristics of fluxes and moisture from different soil profiles are then used to understand the soil layering conditions. Results show that the top soil layer can significantly affect the evolution of soil moisture …

Resilience Within And Resilience Without: Mindfulness And Sustainability Programming Using An Embedded Engineering Librarian Approach, Catherine Wong, Cynthia Carlson

Civil Engineering Faculty Publications

Students are facing an increasingly chaotic world in part due to global climate change and environmental degradation, causing rising levels of stress and anxiety. Mindfulness and sustainability programs were initiated over three years by a faculty-librarian collaborative team to assist first-year engineering students in building environmental literacy and personal resilience skills. The faculty-librarian team established in class and out of class themes, games, assignments, and programming using an embedded librarian approach. Sustainability programming included environmental movie nights with curricular links and conversations about climate change using the World Café methodology. These activities allowed students time outside of class to engage …

Effects Of “Soil-Like” Particle Size On Gas Transport And Water Retention Properties In Aged Municipal Solid Waste From A Sri Lankan Open Dumpsite, M. Shanujah, T.K.K. Chamindu Deepagoda, A. K. Karunarathna, M. C. M. Nasvi, V. Shreedharan, G. L. S. Babu, Kathleen M. Smits, Curtis M. Oldenburg

Civil Engineering Faculty Publications

Open dumps constitute a major source of greenhouse gases (GHGs), predominantly methane and carbon dioxide, in developing countries. In an aged dump, typical waste composition is dominated by the “soil-like” fraction of which physical, hydraulic and gas transport characteristics markedly affect GHG emissions. This study characterized soil-gas diffusivity (Dp/D0), soil-water characteristics (SWC), and particle size distribution in “soil-like” fractions of aged solid waste retrieved at 2.5–5 m depth from an old open dumpsite situated at Kurunegala, Sri Lanka. The “soil-like” fraction was proportioned into three groups based on particle size (0–4.75, 4.75–9.5, and 9.5–25 mm) to investigate the particle size …

Evaporation From Undulating Soil Surfaces Under Turbulent Airflow Through Numerical And Experimental Approaches, Bo Gao, John Farnsworth, Kathleen M. Smits

Civil Engineering Faculty Publications

Evaporation from undulating soil surfaces is rarely studied due to limited modeling theory and inadequate experimental data linking dynamic soil and atmospheric interactions. The goal of this paper is to provide exploratory insights into evaporation behavior from undulating soil surfaces under turbulent conditions through numerical and experimental approaches. A previously developed and verified coupled free flow and porous media flow model was extended by incorporating turbulent airflow through Reynolds-averaged Navier–Stokes equations. The model explicitly describes the relevant physical processes and the key properties in the free flow, porous media, and at the interface, allowing for the analysis of coupled exchange …

Gas-Diffusivity Based Characterization Of Aggregated Agricultural Soils, J.R.R.N. Jayarathne, T.K.K. Chamindu Deepagoda, Timothy J. Clough, M.C.M. Nasvi, Steve Thomas, Bo Elberling, Kathleen Smits

Civil Engineering Faculty Publications

Grazed pastures and cultivated fields are significant sources of greenhouse gas (GHG) emissions, in particular N2O emissions derived from fertilizer deposition and animal excreta. Net surface emissions rely on subsurface gas transfer controlled mainly by diffusion, expressed as the soil-gas diffusivity (Dp/Do). The value of Dp/Do is a function of soil air-filled porosity (e) and gaseous phase tortuosity (T), both of which vary with soil physical properties including soil texture and structure. Agricultural soils are often structurally aggregated and characterized by two distinct regions (inter- and intra-aggregated pores), however, such soils are subjected to frequent compaction and tillage resulting in …

Thin-Walled Steel Tubular Circular Columns With Uniform And Graded Thickness Under Bidirectional Cyclic Loading, Qusay Al-Kaseasbeh, Iraj H.P. Mamaghani

Civil Engineering Faculty Publications

Thin-walled steel tubular circular columns are becoming an increasingly attractive choice as cantilever bridge piers due to their architectural, structural and constructional advantages. This paper aims to evaluate the strength and ductility of thin-walled steel tubular circular columns with uniform thickness (BC) and graded thickness (BGC) under bidirectional cyclic lateral loading in the presence of constant axial force. The analysis is carried out using a finite-element model (FEM) which is substantiated based on the experimental results in the literature. Then, the proposed BGC column with size and volume of material equivalent to the BC column is investigated. As a part …

Accounting For Temperature Effects On The Performance Of Soil Moisture Sensors In Sandy Soils, Michelle Schwartz, Zhen Li, Toshihiro Sakaki, Ali Moradi, Kathleen Smits

Civil Engineering Faculty Publications

Capacitance sensors are widely used to monitor volumetric water content in both field and lab settings due to their low cost, ease of use, and capability of providing continuous measurements. However, these sensors are sensitive to temperature variations. Previous attempts to develop calibration equations that negate thermal effects incorporate many empirical constants that vary based on soil and sensor type. The purpose of this study is to examine the effects of temperature on sensor performance and develop an improved calibration equation for a widely used capacitance soil moisture/temperature sensor, the ECH2O 5TM. Small cell experiments were conducted with silica sands …

Evaluation Of Wind And Solar Energy Investments In Texas, Byungik Chang, Ken Starcher

Civil Engineering Faculty Publications

The primary objective of the project is to evaluate the benefits of wind and solar energy and determine economical investment sites for wind and solar energy in Texas with economic parameters including payback periods. A 50 kW wind turbine system and a 42 kW PV system were used to collect field data. Data analysis enabled yearly energy production and payback period of the two systems.

The average payback period of a solar PV system was found to be within a range of 2-20 years because the large range of the payback period for PV systems were heavily influenced by incentives. …

Applied Fluid Mechanics Lab Manual, Habib Ahmari, Shah Md Imran Kabir

Civil Engineering Faculty Publications

This lab manual provides students with the theory, practical applications, objectives, and laboratory procedure of ten experiments. The manual also includes educational videos showing how student should run each experiment and a workbook for organizing data collected in the lab and preparing result tables and charts.

Degradation Of 3-Nitro-1, 2, 4-Trizole-5-One (Nto) In Wastewater With Uv/H2o2 Oxidation, Amalia Terracciano, Christos Christodoulatos, Agamemnon Koutsospyros, Zhaoyu Zheng, Tsan-Liang Su, Benjamin Smolinski, Per Arienti, Xiaoguang Meng

Civil Engineering Faculty Publications

Insensitive Munition (IM) formulations contain 3-nitro-1,2,4-trizole-5-one (NTO), an energetic compound with the highest aqueous solubility (16 g L⁻¹) among all IM explosives, including 2,4-dinitroanisole (DNAN) and 1-nitroguanidine (NQ); as a result wastewater streams from IM processing facilities can be highly contaminated and potentially toxic. The removal of energetic compounds from wastewater streams prior to their discharge in the environment is imperative, and new technology must be developed to efficiently treat high levels of NTO and other IM compounds in these streams. In this study, the treatment of NTO wastewater by a UV/H₂O₂ oxidation process under …

Experimental And Numerical Study Of Evaporation From Wavy Surfaces By Coupling Free Flow And Porous Media Flow, Bo Gao, Hossein Davarzani, Rainer Helmig, Kathleen M. Smits

Civil Engineering Faculty Publications

The macroscale roughness of the soil surface has significant influences on the mass/energy interactions between the subsurface and the atmosphere during evaporation. However, most previous works only consider evaporation behavior from flat surfaces. Based on experimental and numerical approaches, the goal of this work is to provide a framework for the understanding of the mechanisms of evaporation from irregular soil surfaces at representative elementary volume scale. A coupling free flow-porous media flow model was developed to describe evaporation under nonisothermal conditions. For simplicity, sinusoidal-type wavy surfaces were considered. To validate this modeling approach, an experiment using an open-ended wind tunnel …

Hexahydro-1,3,5-Trinitro-1,3,5-Triazine (Rdx) Reduction By Granular Zero-Valent Iron In Continuous Flow Reactor, Amalia Terracciano, Jie Ge, Agamemnon Koutsospyros, Xiaoguang Meng, Benjamin Smolinski, Per Arienti

Civil Engineering Faculty Publications

Wastewater streams containing hexahydro-1, 3, 5-trinitro-1, 3, 5-triazine (RDX) are subject to regulatory discharge regulations that require processing through industrial waste treatment. Thus, the development of easy-to-apply technologies for the treatment of RDX-laden wastewater streams is imperative. In the present study, the reduction of RDX by granular zero valent iron (GZVI) in batch and column experiments was investigated. Preliminary batch tests conducted under both oxic and anoxic conditions showed that after 3.0 hours of reaction with GZVI, RDX was mainly converted to formaldehyde (CH₂O), nitrate (NO₃ ^- ), and ammonium (NH₄ ⁺ ). Column filtration tests …

Coupled Thermally-Enhanced Bioremediation And Renewable Energy Storage System: Conceptual Framework And Modeling Investigation, Ali Moradi, Kathleen M. Smits, Jonathan O. Sharp

Civil Engineering Faculty Publications

This paper presents a novel method to couple an environmental bioremediation system with a subsurface renewable energy storage system. This method involves treating unsaturated contaminated soil using in-situ thermally enhanced bioremediation; the thermal system is powered by renewable energy. After remediation goals are achieved, the thermal system can then be used to store renewable energy in the form of heat in the subsurface for later use. This method can be used for enhanced treatment of environmental pollutants for which temperature is considered a limiting factor. For instance, this system can be used at a wide variety of petroleum-related sites that …

Evaluation Of Model Concepts To Describe Water Transport In Shallow Subsurface Soil And Across The Soil–Air Interface, Zhen Li, Jan Vanderborght, Kathleen M. Smits

Civil Engineering Faculty Publications

Soil water evaporation plays a critical role in mass and energy exchanges across the land– atmosphere interface. Although much is known about this process, there is no agreement on the best modeling approaches to determine soil water evaporation due to the complexity of the numerical modeling scenarios and lack of experimental data available to validate such models. Existing studies show numerical and experimental discrepancies in the evaporation behavior and soil water distribution in soils at various scales, driving us to revisit the key process representation in subsurface soil. Therefore, the goal of this work is to test different mathematical formulations …

Characterization Of Grain-Size Distribution, Thermal Conductivity, And Gas Diffusivity In Variably Saturated Binary Sand Mixtures, T.K.K. Chamindu Deepagoda, Kathleen Smits, J.R.R.N. Jayarathne, Benjamin M. Wallen, Timothy J. Clough

Civil Engineering Faculty Publications

Characterization of differently textured porous materials, as well as different volumetric porous media mixtures, in relation to mass and heat transport is vital for many engineering and research applications. Functional relations describing physical (e.g., grain-size distribution, total porosity), thermal, and gas diffusion properties of porous media and mixtures are necessary to optimize the design of porous systems that involve heat and gas transport processes. However, only a limited number of studies provide characterization of soil physical, thermal, and gas diffusion properties and the functional relationships of these properties under varying soil water contents, especially for soil mixtures, complicating optimization efforts. …

Characterization Of Mg-Based Bimetal Treatment Of Insensitive Munition 2,4-Dinitroanisole, Emese Hadnagy, Andrew Mai, Benjamin Smolinski, Washington Braida, Agamemnon Koutsospyros

Civil Engineering Faculty Publications

The manufacturing of insensitive munition 2,4-dinitroanisole (DNAN) generates waste streams that require treatment. DNAN has been treated previously with zero-valent iron (ZVI) and Fe-based bimetals. Use of Mg-based bimetals offers certain advantages including potential higher reactivity and relative insensitivity to pH conditions. This work reports preliminary findings of DNAN degradation by three Mg-based bimetals: Mg/Cu, Mg/Ni, and Mg/Zn. Treatment of DNAN by all three bimetals is highly effective in aqueous solutions (> 89% removal) and wastewater (> 91% removal) in comparison with treatment solely with zero-valent magnesium (ZVMg; 35% removal). Investigation of reaction byproducts supports a partial degradation pathway involving …

Bio-Inspired Hybrid Vibration Control Methodology For Intelligent Isolated Bridge Structures, Mariantonieta Gutierrez Soto

Civil Engineering Faculty Publications

Inspired by evolutionary game theory, the biological game of replicator dynamics is investigated for vibration control of bridge structures subjected to earthquake excitations. Replicator dynamics can be interpreted economically as a model of imitation of successful individuals. This paper uses replicator dynamics to reduce vibrations while optimally allocating the control device forces. The control algorithm proposed is integrated with a patented neural dynamic optimization algorithm to find optimal growth rate values with the goal of achieving satisfactory structural performance with minimum energy consumption. A model is described for hybrid vibration control of smart highway bridge structures subjected to earthquake loading.

Stabilization Of Lead (Pb) And Zinc (Zn) In Contaminated Rice Paddy Soil Using Starfish: A Preliminary Study, Deok Hyun Moon, Inseong Hwang, Agamemnon Koutsospyros, Kyung Hoon Cheong, Yong Sik Ok, Won Hyun Ji, Jeong Hun Park

Civil Engineering Faculty Publications

Lead (Pb) and zinc (Zn) contaminated rice paddy soil was stabilized using natural (NSF) and calcined starfish (CSF). Contaminated soil was treated with NSF in the range of 0-10 wt.% and CSF in the range of 0-5 wt.% and cured for 28 days. Toxicity characteristic leaching procedure (TCLP) test was used to evaluate effectiveness of starfish treatment. Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) analyses were conducted to investigate the mechanism responsible for effective immobilization of Pb and Zn. Experimental results suggest that NSF and CSF treatments effectively immobilize Pb and Zn in treated rice paddy soil. TCLP levels for …

Performance Study On Evacuated Tubular Collector Coupled Solar Still In West Texas Climate, Roy Issa, Byungik Chang

Civil Engineering Faculty Publications

Experimental study was performed on a single basin active solar distillation system augmented with a solar collector using evacuated solar tubes. Field tests were conducted over several days under the climatic conditions of West Texas to evaluate the effect evacuated solar tubes have on the daily distillate yield rate. To investigate the feasibility of the solar tubes, active and passive solar stills with and without exterior insulation were examined. The maximum daily production rate for the active distillation system using evacuated solar tubes and the passive distillation system was 3.6 and 1.4 kg/m²day, respectively. The results showed the …

Vulnerability Of Coastal Connecticut To Sea Level Rise: Land Inundation And Impacts To Residential Property, Rebecca Andreucci, Can B. Aktas

Civil Engineering Faculty Publications

Vulnerability indices at the global or national scales require considerable data aggregation where local economic and social impacts remain unnoticed. The goal of this study was to analyze the extent of inundated land from sea level rise and its economic impacts to residential property in coastal communities. Geographic data were integrated with economic and social data at parcel level resolution through GIS. Cumulative land inundation in seven coastal municipalities was calculated as 15 and 25 km², while direct economic costs to residential property was estimated to be $1.3 billion and $2.2 billion for 1 and 2 m sea …

Application Of Gis To Prioritize Brownfield Sites For Green Building Construction Based On Leed Criteria, Can B. Aktas, Paul Bartholomew, Sabrina Church

Civil Engineering Faculty Publications

Although there are many initiatives to create incentives for investors and developers to invest in and redevelop brownfield sites, efficient prioritization of brownfields by taking into account environmental, economic, and social constraints remains a challenge. This study introduces a method to screen numerous brownfields over large geographic areas by using geographic information systems (GIS) and to assess and prioritize such sites for green building suitability based on leadership in energy and environmental design (LEED) criteria. A case study was completed for the greater Bridgeport, Connecticut region. With 279 brownfield sites, the city has among the highest number of brownfields in …

Life Cycle Environmental And Economic Performance Of Biochar Compared With Activated Carbon: A Meta-Analysis, Hashim A. Alhashimi, Can B. Aktas

Civil Engineering Faculty Publications

As the commercial production and distribution of biochar continues to grow internationally, and its applications diversifying from its early uses as soil amendment, it is important to study the environmental impacts and economic performance of biochar in comparison to activated carbon in order to assess its value. The goal of the study was to assess, through a meta-analysis, the environmental and economic performance of biochar in comparison to activated carbon under an equivalent functional unit to adsorb heavy metals. More than 80 data points on adsorption capacity of biochar and activated carbon were identified through literature, which were statistically analyzed …

Heat And Water Transport In Soils And Across The Soil-Atmosphere Interface: 1. Theory And Different Model Concepts, Jan Vanderborght, Thomas Fetzer, Klaus Mosthaf, Kathleen M. Smits, Rainer Helmig

Civil Engineering Faculty Publications

Evaporation is an important component of the soil water balance. It is composed of water flow and transport processes in a porous medium that are coupled with heat fluxes and free air flow. This work provides a comprehensive review of model concepts used in different research fields to describe evaporation. Concepts range from nonisothermal two-phase flow, two-component transport in the porous medium that is coupled with one-phase flow, two-component transport in the free air flow to isothermal liquid water flow in the porous medium with upper boundary conditions defined by a potential evaporation flux when available energy and transfer to …

Heat And Water Transport In Soils And Across The Soil-Atmosphere Interface: 2. Numerical Analysis, Jan Vanderborght, Thomas Fetzer, Klaus Mosthaf, Kathleen M. Smits, Rainer Helmig

Civil Engineering Faculty Publications

In an accompanying paper, we presented an overview of a wide variety of modeling concepts, varying in complexity, used to describe evaporation from soil. Using theoretical analyses, we explained the simplifications and parameterizations in the different approaches. In this paper, we numerically evaluate the consequences of these simplifications and parameterizations. Two sets of simulations were performed. The first set investigates lateral variations in vertical fluxes, which emerge from both homogeneous and heterogeneous porous media, and their importance to capturing evaporation behavior. When evaporation decreases from parts of the heterogeneous soil surface, lateral flow and transport processes in the free flow …

Quality Improvement Of Acidic Soils By Biochar Derived From Renewable Materials, Deok Hyun Moon, Inseong Hwang, Yoon-Young Chang, Agamemnon Koutsospyros, Kyung Hoon Cheong, Won Hyun Ji, Jeong Hun Park

Civil Engineering Faculty Publications

Biochar derived from waste plant materials and agricultural residues was used to improve the quality of an acidic soil. The acidic soil was treated for 1 month with both soy bean stover-derived biochar and oak-derived biochar in the range of 1 to 5 wt% for pH improvement and exchangeable cation enhancement. Following 1 month of treatment, the soil pH was monitored and exchangeable cations were measured. Moreover, a maize growth experiment was performed for 14 days with selected treated soil samples to confirm the effectiveness of the treatment. The results showed that the pH of the treated acidic soil increased …

System-Dynamics Modeling Of Source Mass-Depletion And Risk-Exposure Evolution For Natural Attenuation Processes In The Vadose Zone, Aspasia Kalomoiri, Agamemnon Koutsospyros, Washington Braida, Julius Pavlov

Civil Engineering Faculty Publications

Public health is potentially at risk after a contaminant of concern (COC) is released into the ecosphere. The extent of contamination depends on numerous factors; modeling a contaminant’s dynamic behavior is challenging, given the multitude of relevant parameters and the fluid nature of processes involved. For example, weather events (e.g., wet or dry periods) may affect the mass depletion and the fate and transport of COCs, and hence, the risk assessment of current and potential future exposures. Thus, to give realistic estimates for potential risks, a contaminant’s dynamic behavior must be taken into account in decision-making processes. In this paper, …

Freeze-Thaw Durability Of Concrete Columns Wrapped With Frp And Subject To Corrosion-Like Expansion, Ronald S. Harichandran, M.I. Baiyasi, G. Nossoni

Civil Engineering Faculty Publications

Experiments were conducted to assess the effects of using fiber-reinforced polymer (FRP) wraps, with fibers oriented in the hoop direction, for rehabilitating corrosion-damaged columns. This paper reports findings related to the freeze-thaw durability of concrete specimens with round and square cross sections, wrapped with glass and carbon FRP, after they are subjected to an internal expansive force similar to that generated by corroding steel. The results of the experiment indicate that freeze-thaw cycles have no statistically significant effect on the compressive strength of glass- and carbon-wrapped specimens. Freeze-thaw conditioning generally reduced the longitudinal failure strain of wrapped specimens. The square …

Economic Feasibility Of Campus-Wide Photovoltaic Systems In New England, Jongsung Lee, Byungik Chang, Can B. Aktas, Ravi Gorthala

Civil Engineering Faculty Publications

Compared to the national average residential retail electricity price, Connecticut (CT) had the 4th 26 highest electricity price in the country with 19.23 cents/kWh in September 2015, nearly 50% 27 higher than the national average for price of electricity. This study aims to assess the economic 28 feasibility of the solar PV systems at the campus under realistic constraints, by analyzing actual 29 data from the solar array on campus. The project focused on the economic feasibility of solar PV 30 systems on campus with physical, spatial, and practical constraints that result in a project to 31 deviate from theoretical …