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2020

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Full-Text Articles in Engineering

The Stability Of Nanobubbles And Its Application In Contaminated Sediment Treatment, Shaini Dilsha Aluthgun Hewage Dec 2020

The Stability Of Nanobubbles And Its Application In Contaminated Sediment Treatment, Shaini Dilsha Aluthgun Hewage

Dissertations

This dissertation consists of two sections. First, nanobubbles' stability and behavior are studied using experimental and theoretical approaches. Second, nanobubbles application combined with ultrasound to remediate contaminated sediments is discussed.

The stability study consists of four sections. (i). Laboratory investigation to determine bubble size distributions and zeta potentials for different gases, pH levels, temperatures, and salt conditions. (ii). A theoretical study based on the diffused double layer theory to explain nanobubbles' behavior in different NaCl concentrations. (iii). Nanobubbles' stability in electrolyte solutions under different ion valencies using deionized water, NaCl, Na2SO4, Na3PO4, …


River & Estuary Observation Network: Refinement Of Stage Height Sensor Subsystem For Low Cost And High Reliability, W. D. Kirkey, C. B. Fuller, P. O'Brien, P. J. Kirkey, Ahmed Mahmoud, Andrew Ernest, Javier Guerrero Dec 2020

River & Estuary Observation Network: Refinement Of Stage Height Sensor Subsystem For Low Cost And High Reliability, W. D. Kirkey, C. B. Fuller, P. O'Brien, P. J. Kirkey, Ahmed Mahmoud, Andrew Ernest, Javier Guerrero

Civil Engineering Faculty Publications and Presentations

A system comprised of software and on-site measurements is presented for accurately obtaining water stage data from vented or non-vented submersible pressure sensors installed at autonomous stream gauging stations. The system accounts for pressure sensor offset errors, water density, and local gravitational acceleration to produce a stage height reading which is accurate to either ±0.01 ft (±3 mm) or to the accuracy limit of the sensor, whichever is greater. A 2nd order polynomial expression for determination of water density from temperature and salinity is developed and found to be sufficiently accurate for this purpose. Simulated stage measurements performed in the …


The Compressive And Flexural Strength Of Concrete Containing Recycled Waste Plastic, Isaiah Akinkunmi Dec 2020

The Compressive And Flexural Strength Of Concrete Containing Recycled Waste Plastic, Isaiah Akinkunmi

Master of Science in Civil Engineering Theses

Annually, tons of plastic wastes end up in landfills and the oceans through indiscriminate dumping, constituting a major source of pollution to the environment and threat to human health and marine lives. It therefore necessitates an innovative strategy to help mitigate the environmental hazards caused by this pollution. A feasible eco-friendly strategy is by using granulated plastics, fibers or regrinds in concreting. This research explored the feasibility of this strategy by testing the compressive and flexural strengths of hardened concrete specimens containing varying percent of plastic aggregates used as partial replacement for fine aggregates. The compressive strength of specimens of …


An Experimental Investigation Of Alternative Wave Attenuation Mechanisms For A Modular Breakwater, Richard Perry Dec 2020

An Experimental Investigation Of Alternative Wave Attenuation Mechanisms For A Modular Breakwater, Richard Perry

Electronic Theses and Dissertations

Global warming and sea level rise threaten to render traditional coastal protection structures as less effective. Floating breakwaters offer the advantages of adapting to rising sea level, allowing important material transport to occur, and being able to deploy and adapt to varying environmental conditions (seabed, depth, etc.). Traditional floating breakwaters typically consist of reflective concrete structures that are limited semi-sheltered locations. This research aimed to construct floating breakwaters out of lightweight materials with a smaller footprint while utilizing alternative attenuation mechanisms. Three breakwaters consisting of a box, beach, and pipe designs were constructed at 1:40 scale and tested in a …


Effects Of City Growth On Tall Building Cladding Fatigue, Hang You Dec 2020

Effects Of City Growth On Tall Building Cladding Fatigue, Hang You

Electronic Thesis and Dissertation Repository

As city develops there will be changes in the aerodynamic characteristics due to varying building surrounding and topology. For example, the city growth around a tall building can cause an increase in wind load due to venturi or wake effects or decrease due to sheltering effects depending on the type of surrounding. The densification of cities will also increase the turbulence level due to wake effects. In the present study, the implication of these changes on the aerodynamic forces on cladding connections is investigated. With increased fluctuations in the wind loads, the cladding connections will also experience stress fluctuations, which …


Investigating The Role Of Iron In The Photogranulation Phenomenon, Abeera Ayaz Ansari Dec 2020

Investigating The Role Of Iron In The Photogranulation Phenomenon, Abeera Ayaz Ansari

Doctoral Dissertations

Oxygenic photogranules (OPGs) are dense spherical microbial aggregates that are used for self-aerating wastewater treatment. Filamentous cyanobacteria are key granulating species, providing structural backbone and integrity in OPGs. Currently, the mechanisms for selecting filamentous cyanobacteria and their ability to form spherical OPGs are not well understood. Literature shows that iron (Fe) availability plays a significant role in the cyanobacterial growth and colony formation. Moreover, Fe availability is known to be dependent upon light, which is an essential growth substrate for the phototrophs. This research has investigated the role of Fe in the photogranulation phenomenon and the impact of light intensity …


Feasibility Of Geothermal Energy Piles In New Orleans Alluvial Soils, Patrick A. Thurmond Dec 2020

Feasibility Of Geothermal Energy Piles In New Orleans Alluvial Soils, Patrick A. Thurmond

University of New Orleans Theses and Dissertations

Geothermal energy piles offer the benefits of modifying existing construction practices to reduce costs associated with heating and cooling. A major obstacle today in effective utilization of these systems is a general lack of site-specific data on the thermal properties of subsoils. To maximize the potential efficiency of these systems, engineers require an understanding of the potential impact of this technology on existing foundation design methodology as well as a means for quantifying potential heat transfer through soil by determination of the soil’s thermal conductivity. This study examines the feasibility of energy piles with a focus on alluvial soils found …


Geo-Structural Analysis Of Integral Abutment Bridges, Biyi Li Dec 2020

Geo-Structural Analysis Of Integral Abutment Bridges, Biyi Li

Electronic Thesis and Dissertation Repository

Integral abutment bridges are jointless bridges where bridge decks and girders are integrated with abutments. The longitudinal displacements and rotations of the bridge are partially accommodated by the soil-pile system wherein the soil surrounding the piles generates active and reactive lateral forces when the piles deflect due to the movement of the superstructure. Since the soil stress-strain responses are inherently nonlinear, the pile deflection and the soil stiffness are interdependent. Consequently, evaluating soil-pile interactions requires a detailed geo-structural analysis. There are two common approaches used to idealize the soil-pile interactions for laterally loaded piles: the p-y and continuum mechanics approaches …


The Impact Of Grinding Time On Properties Of Cement Mortar Incorporated High Volume Waste Paper Sludge Ash, Ali A. Shubbar, Monower Sadique, Mohammed S. Nasr, Zainab S. Al-Khafaji, Khalid S. Hashim Dec 2020

The Impact Of Grinding Time On Properties Of Cement Mortar Incorporated High Volume Waste Paper Sludge Ash, Ali A. Shubbar, Monower Sadique, Mohammed S. Nasr, Zainab S. Al-Khafaji, Khalid S. Hashim

Karbala International Journal of Modern Science

Cement is considered a base material in preparing blending mixtures that applying in various projects in the civil engineering field. Nevertheless, the cement production process cause indubitable negative environmental influences such as emitting CO2. The production of cement produces around 7% of the global CO2 emissions. Thus, searching for alternate binders in building processes to minimise or substitute cement has been one of the social problems. A by-product or waste products are among the potential alternatives to the mentioned problem. The present investigation involves the consumption of paper sludge ash (PSA) waste as cement replacement to produce …


Reliability-Based Calibration Of Design Wind Load, Snow Load And Companion Load Factors Considering Climate Change Effect, Qian Tang Dec 2020

Reliability-Based Calibration Of Design Wind Load, Snow Load And Companion Load Factors Considering Climate Change Effect, Qian Tang

Electronic Thesis and Dissertation Repository

Wind load and snow load are two of the environmental loads that need to be considered for structural design. This study compared the statistical characteristics of the annual maximum thunderstorm and non-thunderstorm winds based on the updated wind speed dataset and carried out the extreme value analysis for wind load by treating the synoptic and thunderstorm winds separately. The results indicated that for southern Ontario and the southern part of the Prairies, the extreme winds could be dominated by thunderstorm winds. The consideration of both thunderstorm winds and synoptic winds separately to recommend the reference wind velocity pressure for the …


Finite Element Analyses And Random Field Modeling Of Naturally Corroded Underground Energy Pipelines, Ji Bao Dec 2020

Finite Element Analyses And Random Field Modeling Of Naturally Corroded Underground Energy Pipelines, Ji Bao

Electronic Thesis and Dissertation Repository

Metal-loss corrosion is one of the major threats to the integrity of oil and natural gas pipelines. The Fitness-For-Service (FFS) assessment is commonly carried out to demonstrate the integrity of the corroded pipelines. The naturally occurring corrosions on the external surfaces are irregularly shaped three-dimensional features. Due to the geometric complexity of the natural corrosion features, the research of FFS assessment in the previous studies always employed the pipe segments containing artificially induced corrosion features. However, since artificial features are in general regular-shaped, e.g. cubic or semi-ellipsoidal, they do not capture geometric characteristics of naturally occurring corrosions. The thesis develops …


Laboratory Testing And Mechanistic Analysis Of Treated Subgrade Soils, Hari Kumar Reddy Yarrapureddi Dec 2020

Laboratory Testing And Mechanistic Analysis Of Treated Subgrade Soils, Hari Kumar Reddy Yarrapureddi

Civil Engineering Theses

Calcium-based stabilizing agents such as cement and lime have been extensively used to improve the engineering properties of base and subgrade layers of pavement systems. Recently, polymers and chemical stabilizers have become popular due to cost efficiency, ease of application, and fast curing times. In this study, California Bearing Ratio (CBR) values of polymer and chemical treated soils were compared with the CBR values of soils treated with conventional stabilizers. Parametric sensitivity analyses was carried out on key parameters including the type of subgrade soil, stabilizing agent, stabilizing agent treatment levels, and moisture conditioning. Additionally, numerical analyses was performed to …


Expanding The Concept Of Comprehensive Area Ratio Parameter To The South-Central States Towards Simplifying The Structural Evaluation Of Flexible Pavements At The Network Level, Nitish R. Bastola Dec 2020

Expanding The Concept Of Comprehensive Area Ratio Parameter To The South-Central States Towards Simplifying The Structural Evaluation Of Flexible Pavements At The Network Level, Nitish R. Bastola

Civil Engineering Theses

The surface deflection bowl data collected through Non-Destructive Testing (NDT) has been widely utilized by various Department of Transportation (DOTs) in the South-Central States and other places. The primary purpose of using deflection-based NDTs in network-level assessment is to identify a weak pavement section that requires further analysis at the project level. The falling weight deflectometer (FWD) test is one of the common NDT based tests utilized by highway agencies in assessing the performance of the flexible pavement. However, a robust method to evaluate pavement sections utilizing FWD data from all the sensors are seldom developed. There is always a …


Housing Pre-Fabrication And Resource Optimization, Emma Dubensky Dec 2020

Housing Pre-Fabrication And Resource Optimization, Emma Dubensky

Honors Theses

Enclosure during construction is often time-consuming, expensive, and at the mercy of the weather. By introducing methods for manufacturing prefabricated enclosure components such as wall panels and roof sections, the impact of the three major variables is reduced. Designs for trusses, roof sections, wall sections, and foundations were developed and selected using civil engineering principles; and manufacturing and logistical processes were optimized using engineering and project management skill sets. These multi-disciplinary efforts were combined to create an accessible and versatile set of designs and instructions that can improve the effectiveness of both a skilled and non-skilled volunteer workforce. By creating …


State Of The Art In Composition, Fabrication, Characterization, And Modeling Methods Of Cement-Based Thermoelectric Materials For Low-Temperature Applications, Xiaoli Liu, Ruchita Jani, Esther Orisakwee, Conrad Johnston, Piotr Chudzinski, Ming Qu, Brian Norton, Niall Holmes Dr., Jorge Kohanoff, Lorenzo Stella, Hongxi Yin, Kazuaki Yazawa Dec 2020

State Of The Art In Composition, Fabrication, Characterization, And Modeling Methods Of Cement-Based Thermoelectric Materials For Low-Temperature Applications, Xiaoli Liu, Ruchita Jani, Esther Orisakwee, Conrad Johnston, Piotr Chudzinski, Ming Qu, Brian Norton, Niall Holmes Dr., Jorge Kohanoff, Lorenzo Stella, Hongxi Yin, Kazuaki Yazawa

Articles

The worldwide energy crisis and environmental deterioration are probably humanity’s greatest challenges. Thermoelectricity, which allows for the mutual conversion between thermal and electrical energy, has become a promising technology to alleviate this challenge. Increasingly more research focuses on how to fabricate and apply thermoelectric materials for harvesting energy and regulating the indoor thermal environment. However, only a few studies have focused on cementitious materials with thermoelectric potential. Thermoelectric cement is a composite material in which particular additives can enhance the thermoelectric performance of ordinary cement. By potentially replacing traditional construction materials with thermoelectric cement in building applications, electricity could be …


Housing Prefabrication And Resource Optimization, Megan Scherpereel Dec 2020

Housing Prefabrication And Resource Optimization, Megan Scherpereel

Honors Theses

Enclosure during construction is often time-consuming, expensive, and at the mercy of the weather. By introducing methods for manufacturing prefabricated enclosure components such as wall panels and roof sections, the impact of the three major variables is reduced. Designs for trusses, roof sections, wall sections, and foundations were developed and selected using civil engineering principles; and manufacturing and logistical processes were optimized using engineering and project management skill sets. These multi-disciplinary efforts were combined to create an accessible and versatile set of designs and instructions that can improve the effectiveness of both a skilled and non-skilled volunteer workforce. By creating …


Loup Public Power District Fishing Pier & Parking Lot, Tyler Ruwe Dec 2020

Loup Public Power District Fishing Pier & Parking Lot, Tyler Ruwe

Honors Theses

This project was performed in fulfillment of the Civil Engineering Senior Design class (CIVE 489H). The goal of this project was to design an ADA compliant fishing pier and parking lot for the Loup Public Power District in Columbus, Nebraska. The fishing pier and parking lot will be located near the northeast corner of Lake North. A four-member team was formed to delegate the workload to accomplish this design project. I, Tyler Ruwe, served as the team’s project manager and structural engineering lead. Other disciplines of this design project included work involved in geotechnical, water resources, environmental, and transportation engineering. …


Mechanical Alloying-Assisted Coating Of Fe–Al Powders On Steel Substrate, Alfian Noviyanto, Sri Harjanto, Wahyu Bambang Widayatno, Agus Sukarto Wismogroho, Muhamad Ikhlasul Amal, Nurul Taufiqu Rochman Dec 2020

Mechanical Alloying-Assisted Coating Of Fe–Al Powders On Steel Substrate, Alfian Noviyanto, Sri Harjanto, Wahyu Bambang Widayatno, Agus Sukarto Wismogroho, Muhamad Ikhlasul Amal, Nurul Taufiqu Rochman

Makara Journal of Technology

The coating layer of Fe–Al powders on the steel substrate was prepared by mechanical alloying at room temperature. Fe, Al, and the steel substrates were milled with high-energy ball milling for 32 h with a ball-to-powder ratio of 8 in an argon atmosphere to prevent oxidation during milling. Although mechanical alloying was performed for 32 h, no new phases were observed after mechanical alloying, as analyzed by X-ray diffraction. However, the crystallite size of the milled powders for 32 h decreased by factor two compared with the initial powders. Scanning electron micrographs showed that the coating layers formed >8 h …


Performance Of Free-Space Optical Communication Systems Using Optical Amplifiers Under Amplify-Forward And Amplify-Received Configurations, Ucuk Darusalam, Arockia Bazil Raj, Fitri Yuli Zulkifli, Purnomo Sidi Priambodo, Eko Tjipto Rahardjo Dec 2020

Performance Of Free-Space Optical Communication Systems Using Optical Amplifiers Under Amplify-Forward And Amplify-Received Configurations, Ucuk Darusalam, Arockia Bazil Raj, Fitri Yuli Zulkifli, Purnomo Sidi Priambodo, Eko Tjipto Rahardjo

Makara Journal of Technology

With the growth of digital technology in the stage of industrial revolution 4.0, the demand for broadcasting large amounts of information to last mile users has increased. Free-space optical (FSO) communication is one of the telecommunication platforms that has shown immense potential in meeting the demand for information broadcasting. In this work, the performance of FSO communication based on wavelength division multiplexing with a data rate of 80 Gbps is investigated through simulations. The configuration of optical amplifiers in the FSO system is set up on the basis of the amplify-forward and amplify-received configurations to expand the network. The investigation …


Use Of Viscoplastic Damper For Improving The Resistance Of Steel Frames To Blast Loading, Gholamreza Abdollahzadeh, Hadi Faghihmaleki, Hamed Hamidi Jamnani, Atefeh Ebrahimi Bardar Dec 2020

Use Of Viscoplastic Damper For Improving The Resistance Of Steel Frames To Blast Loading, Gholamreza Abdollahzadeh, Hadi Faghihmaleki, Hamed Hamidi Jamnani, Atefeh Ebrahimi Bardar

Makara Journal of Technology

In this paper, we evaluated the effect of viscoplastic dampers on the response of steel frames under blast loading. We used SAP2000 software and link elements to investigate the responses of nine-story steel frames with and without dampers. The proposed viscoplastic damper is a new type of viscous damper. The application of this damper is based on the availability of its constituent materials. The damper acts as a viscoelastic damper at low levels of vibration, but it acts as a combination of viscoelastic operator and metal-yielding device at extreme levels of vibration. With respect to the height of the structure, …


A Density Functional Theory Study On Using Montmorillonite To Reduce Air Pollution, Triati Dewi Kencana Wungu, Meqorry Yusfi, Suprijadi Suprijadi Dec 2020

A Density Functional Theory Study On Using Montmorillonite To Reduce Air Pollution, Triati Dewi Kencana Wungu, Meqorry Yusfi, Suprijadi Suprijadi

Makara Journal of Technology

In this study, density functional theory (DFT) method is used to investigate the possibility of using a smectite clay mineral called montmorillonite (MMT) in reducing heavy metals, such as Cd, through Cd adsorption. The mechanism of Cd adsorption in MMT is observed theoretically, and the tetrahedrally isomorphic substitution on the upper layer of MMT is considered to observe the role of Al and Fe in strengthening Cd adsorption. Two types of MMT are modeled in this study: Al-MMT and Fe-MMT. The Al-MMT means that Al substitutes one atom in the upper tetrahedral layer of MMT, while Fe-MMT means that Fe …


Influence Of The Shaping Process On The Tensile Properties Of Steel Reinforcement Bars Carbon Steel Grades Bjtp24 And Bjts40, Nuraziz Handika, Ridha Amalia Idhar, Jessica Sjah, Essy Arijoeni, Elly Tjahjono Dec 2020

Influence Of The Shaping Process On The Tensile Properties Of Steel Reinforcement Bars Carbon Steel Grades Bjtp24 And Bjts40, Nuraziz Handika, Ridha Amalia Idhar, Jessica Sjah, Essy Arijoeni, Elly Tjahjono

Makara Journal of Technology

According to the current applicable national standard in Indonesia, i.e. SNI 07 2529 1991, in addition to the limitation on the loading rate, the steel bar must be reduced, formed, or lathed, as part of the shaping process of samples. This study determined and compared the effect of the shaping process on the yield strength, ultimate strength, and percent elongation by conducting tensile tests of steel bar grade BJTS40, i.e. deformed bar type of steel, and grade BJTP24, i.e., plain bar type of steel. Three diameters of the deformed bar (BJTS40) and one diameter of the plain bar (BJTP24) were …


Iso 9001:2015 Risk-Based Thinking: A Framework Using Fuzzy-Support Vector Machine, Ralph Sherwin A. Corpuz Dec 2020

Iso 9001:2015 Risk-Based Thinking: A Framework Using Fuzzy-Support Vector Machine, Ralph Sherwin A. Corpuz

Makara Journal of Technology

Risk-based thinking (RBT) is one of the distinct new features of the International Organization for Standardization 9001:2015. Interestingly, the standard does not prescribe any tools. Hence, organizations are puzzled as to the extent of conformance. Some organizations have adopted formal tools. However, these tools seem insufficient in linking the standard into an evidence-based decision support system. To resolve gaps in RBT implementation, this paper proposes a framework based on fuzzy inference system (FIS) and support vector machine (SVM) to automate risk analysis and evaluation, proposal and verification of action plans, and prediction of the feasibility of risks and opportunities according …


Benefits Of Pre-Construction Analysis: Cet Senior Capstone Expands Understanding Of An Urban Refuge At Gallopnyc Sunrise Stables, Aalaa Mohammed Dec 2020

Benefits Of Pre-Construction Analysis: Cet Senior Capstone Expands Understanding Of An Urban Refuge At Gallopnyc Sunrise Stables, Aalaa Mohammed

Publications and Research

For any construction project, there exists a phase of planning known as “pre-construction.” This initial phase of the project provides a definition of the project, identification of potential issues, planning and scheduling, scope, cost estimation, and analysis of needs for the job. My research analyzes a pre-construction case study conducted for Gallop NYC’s Stable in Howard Beach, Queens. The findings suggest that the practice of construction planning is effective in order to avoid delays in construction itself and ensure successful project completion. Supporting literature examines some of the best practices for pre-construction analysis. These include but are not limited to: …


Bio-Binder—Innovative Asphalt Technology, Amir Tabakovic Dec 2020

Bio-Binder—Innovative Asphalt Technology, Amir Tabakovic

Articles

The global road network spans 16.3 million km [1], of which 5 million km is in the EU. These road networks fulfil major economic and social goals by facilitating the movement of goods and people throughout the EU, and are therefore of the utmost importance to the economic and social life of the EU [2]. National governments invest heavily in their road networks, e.g., in 2014, EUR 53.33 billion was invested in the development and maintenance of the EU road network [3]. Each year, the world produces 1.6 trillion tonnes of asphalt [4], of which 218 million tonnes is produced …


Ionic Conductiviy Of Alginate-Nh4cl Polymer Electrolyte, Nurhasniza Mamajan Khan, Noor Saadiah Mohd Ali, Ahmad Faizrin Ahmad Fuzlin, Ahmad Salihin Samsudin Dec 2020

Ionic Conductiviy Of Alginate-Nh4cl Polymer Electrolyte, Nurhasniza Mamajan Khan, Noor Saadiah Mohd Ali, Ahmad Faizrin Ahmad Fuzlin, Ahmad Salihin Samsudin

Makara Journal of Technology

This study aims to produce a solid biopolymer electrolyte (SBE) by doping ammonium chloride (NH4Cl) into alginate. Solution casting was used to prepare the alginate–NH4Cl SBE system. Electrical impedance spectroscopy was performed to analyze the electrical properties of the SBE under the applied frequency range of 50 Hz–1 MHz. The incorporation of 8 wt.% NH4Cl enhances the ionic conductivity of the SBE up to 3.18 × 10-7 S/cm at ambient room temperature. Fourier transform infrared spectroscopy shows that complexation occurs between the hydroxyl (-OH), carboxylate (COO-) and ether linkage (C-O-C) functional groups due to the formation of inter- and intra-molecular …


Influence Of Lithium Bromide On Electrical Properties In Bio-Based Polymer Electrolytes, Ahmad Faizrin Fuzlin, Bouchta Sahraoui, Ahmad Salihin Samsudin Dec 2020

Influence Of Lithium Bromide On Electrical Properties In Bio-Based Polymer Electrolytes, Ahmad Faizrin Fuzlin, Bouchta Sahraoui, Ahmad Salihin Samsudin

Makara Journal of Technology

This research presents the influence of lithium bromide (LiBr) on the electrical properties of alginate in bio-based polymer electrolytes (BBPEs) system. Bio-based alginate was prepared using the solution casting technique with various LiBr compositions. The ionic conductivity and electrical properties of the prepared BBPEs samples were studied using electrical impedance spectroscopy over a frequency range of 50 Hz–1 MHz. A maximum ionic conductivity of 7.46 × 10−5 S cm-1 was obtained for a sample containing 15 wt. % lithium bromide-doped alginate BBPEs at ambient temperature (303 K). The electrical analysis revealed that the most conductive sample based on alginate-LiBr BBPEs …


Hydraulic And Mineralogical Characterization Of Organoclay Before And After Reaction With Non-Aqueous Phase Liquid (Napl), Mostafa Afzalian Dec 2020

Hydraulic And Mineralogical Characterization Of Organoclay Before And After Reaction With Non-Aqueous Phase Liquid (Napl), Mostafa Afzalian

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Sediment capping—a method used to stabilize and remediate contaminated subaqueous sediment in lakes or river shores by covering the contaminant with multiple layered materials— is a more effective, economic, and durable in situ treatment compared to ex situ methods such as dredging. The caps are typically composed of porous geomaterials such as gravels, sands, Reactive Core Mat (RCM), including reactive soils (e.g., organoclay) and geosynthetics (e.g., geotextiles). The designed caps are regarded as water-permeable so as not to disturb the sediment; however, the caps become unsaturated state because of trapped gas generated from the decomposition of organic matter. Most of …


3d Study Of Gas Hydrate Formation And Dissociation In Porous Media And Dem Modeling Of Granular Materials, Zaher Jarrar Dec 2020

3d Study Of Gas Hydrate Formation And Dissociation In Porous Media And Dem Modeling Of Granular Materials, Zaher Jarrar

Doctoral Dissertations

Natural methane gas hydrates availability and ongoing rise in demand for energy, motivated researchers to consider gas hydrates as a potential energy source. Production of methane from hydrate-bearing sediments requires hydrate dissociation for releasing mobile methane gas in sediments prior to gas production operations. Fines may migrate through or clog the pore space of sandy sediments depending on the geometry and topology of the pore space. This dissertation employs unique in situ experiments and techniques to gain a comprehensive understanding of the associated physical processes (such as fines migration, clogging and gas driven fracture) and validation of hydrate dissociation models’ …


Behavior Of Concrete Structures Reinforced With High Strength Steel, Rahman S. Kareem Dec 2020

Behavior Of Concrete Structures Reinforced With High Strength Steel, Rahman S. Kareem

Graduate Theses and Dissertations

The structural strength and corrosion resistance of concrete members are improved when A1035 steel is used as the main reinforcement. The enhancement of A1035 is achieved by the modification of the composition and microstructure of the steel. Therefore, the behavior of concrete structures reinforced with high-performance steel (A1035) is different from those reinforced with the regular steel (A615). Concrete bridge decks reinforced with different amounts of A1035 were studied in this research program. The structural behavior of twelve concrete bridge decks reinforced with A615 Grade 420 (60 ksi) and A1035 Grade 830 (120 ksi) steel was investigated at both service …