Civil and Environmental Engineering Commons^™

The Effect Of Reinforcing Bar Bend Radius On The Strength And Behavior Of Knee Joints, Xitong Zhou, Christopher S. Williams, Hwa Ching Wang

The Summer Undergraduate Research Fellowship (SURF) Symposium

The strut-and-tie method (STM) is used by structural engineers to design discontinuity regions of reinforced concrete structures. Using STM, the stress distribution in a concrete member is expressed as a set of struts, ties, and nodes in a strut-and-tie model. These components are then proportioned and evaluated to develop an appropriate design. One type of node that appears in knee joints (i.e., frame corners) subjected to closing moments is referred to as a curved-bar node. Although curved-bar nodes represent a unique concentration of stresses in a structure, little research focused on curved-bar node design has been conducted. In response to …

Hazard Assessment Of Meteoroid Impact For The Design Of Lunar Habitats, Herta Paola Montoya, Shirley Dyke, Julio A. Ramirez, Antonio Bobet, H. Jay Melosh, Daniel Gomez

The Summer Undergraduate Research Fellowship (SURF) Symposium

The design of self-sustaining lunar habitats is a challenge primarily due to the Moon’s lack of atmospheric protection and hazardous environment. To assure safe habitats that will lead to further lunar and space exploration, it is necessary to assess the different hazards faced on the Moon such as meteoroid impacts, extreme temperatures, and radiation. In particular, meteoroids pose a risk to lunar structures due to their high frequency of occurrence and hypervelocity impact. Continuous meteoroid impacts can harm structural elements and vital equipment compromising the well-being of lunar inhabitants. This study is focused on the hazard conceptualization and quantification of …

Modelling Of Phase Transforming Cellular Material (Pxcm), Chidubem N. Enebechi, Yunlan Zhang, David Restrepo Arango, Pablo Zavattieri

The Summer Undergraduate Research Fellowship (SURF) Symposium

Phase transforming cellular materials (PXCMs) are a new class of materials that can go through large deformation and return to their original configuration. Currently, there are reliable cellular materials that can resist large deformation, for example, honey comb; however, when these materials are compared to PXCMs, they cannot stay in their elastic range. The biggest advantage about PXCMs is that they are not only inexpensive materials, but they are also highly-durable and they absorb and dissipate high amounts of energy. The main concept behind PXCMs is that they contain unit cells that have stable configurations. Each stable configuration of the …

Purdue Airsense: An Affordable Way To Measure And Study Air Pollution, Stephane Junior Nouafo Wanko, Shadi Tariq Azouz, Ruihang Du, Brandon Boor, Greg Michalski

The Summer Undergraduate Research Fellowship (SURF) Symposium

Air pollution is a major health hazard worldwide, accounting for one-eighth of all deaths in 2012 (World Health Organization). Globally, there is a severe lack of ground-based spatiotemporal monitoring of gaseous and particulate air pollutants, particularly in Africa, South and Central America, and the Middle East. This is in great part due to the high costs of air quality instrumentation that meet accuracy and reliability criteria set by monitoring agencies. The air quality data that is available is often not presented to the public in a user-friendly manner. Taking advantage of recent developments in low-cost sensing technologies, an integrated sensor …

Buckling Of Cylindrical Shells Under Wind Loading, Tianlong Sun, Eyas Azzuni, Sukru Guzey

The Summer Undergraduate Research Fellowship (SURF) Symposium

Cylindrical shells such as aboveground steel storage tanks are widely used to store gases, chemicals and fuels. Stiffener rings are introduced to prevent cylindrical shells from buckling due to wind loads. The current top wind stiffener design rules used in the USA for such cylindrical storage tanks are specified in API 650. However, the design methodology of top stiffener rings is overly conservative. Therefore, relaxation of the design rules for the top stiffener is investigated in this study. The API 650 mandated top stiffener size was reduced to the same size as the mandated intermediate stiffener ring in this study. …

Post-Earthquake Fire Assessment Of Steel Buildings, Yi Li, Rachel Chicchi, Amit H. Varma

The Summer Undergraduate Research Fellowship (SURF) Symposium

Resilience of structural systems after hazardous events is a crucial concern of building design. An abundance of research has focused on hazards such as seismic and fire separately. This project conducted a multi-hazard study on steel buildings considering both seismic and fire damage. A literature review of the behavior of steel-framed buildings due to fires after earthquakes, known as post-earthquake fires (PEF), is offered. The new PEF methodology, delivered in this study, starts with creating a three dimensional (3D) model of the examined steel building using the finite element method software, ABAQUS. Next, varying intensities of seismic and fire hazards …

Effect Of Moment Gradient And Load Height With Respect To Centroid On The Reliability Of Wide Flange Steel Beams Subject To Elastic Lateral Torsional Buckling, Christopher D. Eamon, Alexander W. Lamb, Kapil Patki

Civil and Environmental Engineering Faculty Research Publications

The reliability of doubly-symmetric wide flange steel beams designed to the AISC Specification for Structural Steel Buildings subjected to elastic lateral torsional buckling was evaluated when considering variation in moment gradient and load height. The analysis considers continuous loads on spans subjected to various end moments with supports that are torsionally fixed and laterally supported, without additional intermediate restraints. Dead load, occupancy live load, and beam resistance random variables were considered. Beam lateral torsional buckling resistance was evaluated from numerical solution of a fundamental differential equation that accounts for the effect of moment gradient and load height. In some cases, …

Spectroscopic Contrast Of Diarylethene Molecules On Octanethiol Monolayer, Arramel Arramel, Tibor Kudernac, Nathalie Katsonis, Bernard Lucas Feringa, Bart Jan Van Wees

Makara Journal of Technology

We present a systematic scanning tunneling microscopy (STM) study of bias-dependent imaging of disulfur diarylethene (2S-DE) molecules on octanethiol (C8) monolayer at room temperature. In a rigid confinement of the C8 matrix, we did not observe any significant variation in the appearance of the 2S-DE. On the contrary, a reversal in the apparent height of the 2S-DE was present when the molecule was situated on a gold vacancy island. We attributed this finding to the presence of a new electronic state that became accessible for a tunneling event. In addition, the C8 surface structure underwent a reversible phase transformation from …

Residual Stress Measurements On The Tig Weld Joint Of 57fe15cr25ni Austenitic Steel For Structural Material Applications By Means X-Ray Diffraction Techniques, Parikin Parikin, Agus Hadi Ismoyo, Riza Iskandar, Arbi Dimyati

Makara Journal of Technology

Measurements of residual stress on the 57Fe25Cr15Ni steel plate with no-filler TIG-welding process were carried out. This work was conducted to determine the nature of weld ability in synthesized steel. The bulks were formed in a dimension of 30x20x7 mm3 to ease data retrieval. Results show that the largest residual stress occurred in the weld metal area, amounting to 82.40 MPa with lattice stretching of 0.18%. Conversely, the values decreased to 65.92 MPa and a stretch of 0.14% in the HAZ area. This residual stress is a tensile stress that can reduce the mechanical strength of the material since it …

An Efficient Palladium-Thiourea Catalysed Heck Cross-Coupling Reaction For Molecular Electronic Interest, Wan M. Khairul, Mohd Shahrul Shahmi Md Shariff, Rafizah Rahamathullah, Adibah Izzati Daud, Mustaffa Shamsuddin, Siti Kamilah Che Soh

Makara Journal of Technology

The synthesis and utilization of C-C bonds formation are concerned about the key steps for the building of several conducting molecular electronics involving many asymmetric catalysts approached, which is an essential task that most researchers would ignore in preparing these materials to enhance the production yield of cross-coupling materials. Despite the enormous progress, there still remains a great demand for economic and practicable cross-coupling processes involving ultra-low catalyst loadings with high turnover numbers due to the employment of conventional metal catalyst. Thus, there has been an excessive interest to cultivate non-phosphine palladium catalysts for excellent achievement of activity, stability, and …

A Study On Dielectric Properties Of The Cellulose Derivative-Nh4br-Glycerol- Based The Solid Polymer Electrolyte System, Nur Muhitul Jalilah Rasali, Saifful Kamaluddin Muzakir, Ahmad Salihin Samsudin

Makara Journal of Technology

The characterization of biopolymer-based solid polymer electrolytes (SPEs) has been carried out in this present work. Cellulose derivative was chosen due to its superior physical attributes. In this work, NH4Br-doped glycerol plasticized carboxyl methylcellulose-based SPEs were successfully prepared via the solution casting method. The conductivity and dielectric properties of the prepared films were investigated using the impedance analysis which presented ~1.91×10-3 Scm-1 (with addition of 6 wt% of glycerol). In addition, the studied SPE system shows a non-Debye behaviour without a single relaxation time. The findings of the research indicate that the complexes of NH4Br and glycerol in the cellulose …

Urban Drainage Management And Flood Control Improvement Using The Duflow Case Study: Aur Sub Catchment, Palembang, South Sumatra, Indonesia, Charlotte De Fraiture, Robiyanto Hendro Susanto, F.X. Suryadi, Harrini Mutiara Hapsari Wahyu

Makara Journal of Technology

Urban flooding often times staggers the livelihood in an urban area, which most likely happens in the lowland urban area. Therefore, the existing urban drainage system should be improved in order to tackle the upcoming urban flooding events, which are more than likely to be more devastating than those in the previous years. The research location is in Palembang, Sumatra, Indonesia, where 30% of its urban part is a lowland area. The selected Aur Sub Catchment is located in Silaberanti. The main objective of this research is to improve the current drainage system in order to achieve the optimal design …

Ethanol Purification Using Activated Natural Zeolite, Chandra Wahyu Purnomo, Nelliza Putri, Indra Perdana, Hirofumi Hinode

Makara Journal of Technology

Bio ethanol is one of the potential fuels in the future. However, ethanol in water mixture has an azeotropic concentration of 95.6 wt. %, which makes it difficult to purify further. The common method of purification is by using an azeotropic distillation column, which requires an intensive energy and an addition of specific solvent. In this study, ethanol purification is done using an adsorption column packed with zeolite Raschig rings. The natural zeolite ring was modified beforehand using the NaOH solution to enhance the material’s water adsorption performance. The ethanol purity can reach more than 99% with the modified zeolite …

Physical And Mechanical Properties Of Palm Kernel Oil-Based Polyester Polyurethane/Multi-Walled Carbon Nanotube Composites, Khairul Anuar Mat Amin, Muhammad Alif Zailani, Nurul Nabilah Zulkifli, Khairiah Haji Badri

Makara Journal of Technology

In this study, polyurethane (PU) films from palm kernel oil-based polyester (PKO-p) incorporated multi-walled carbon nanotubes (MWNTs) are prepared via a evaporative casting method. Nanoparticle fluid dispersions containing 0.02%, 0.03%, and 0.05% wt. of MWNTs are added into PKO-p based resin and mixed by digital probe sonicator for 30 min followed by mixing with isocyanate to produce PU-MWNTs composite films. The mechanical properties, swelling, water vapour transmission rate (WVTR) and conductivity of the PU-MWNTs composite films are examined. Results show that the toughness (T) or flexibility, the tensile strength (TS), and Young’s modulus (YM) values of PU-MWNTs composite films increase …

Personality Trait Based Intervention For Workplace Accident Prevention, Yassierli Yassierli, Nurhayati Nurhayati, Marisa Anatasia, Shamsul Bahri

Makara Journal of Technology

Previous research has suggested that some traits may be useful as the predictors of risk behaviours behaviors. Therefore, personality traits seem to play a role in accident involvement. The purpose of this study is was to explore the relationship between the personality traits based on the Big Five Inventory (BFI) and worker accident experiences in order to elaborate personality traits based intervention for workplace accident prevention. A cross cross-sectional study was conducted among 173 workers in a cement company using a set of questionnaires consisting of respondents’ characteristics, BFI, and self-reported accident experience. The correlations were computed using Goodman Kruskal’s …

Viscoelastic Analysis And Fatigue Characterization Of Bituminous Materials In Two Length Scales Under The Influence Of Aging, Santosh Reddy Kommidi

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

Fatigue cracking in asphalt concrete (AC) is of immense importance to pavement design and analysis because it is one of the most important forms of distress that can lead to structural failure in pavement. Once started, these types of cracks can be combined with other environmental factors leading to detrimental effects such as faster rates of pavement deterioration and shortened pavement life and functionality.

Currently AASHTO TP101, also known as linear amplitude sweep (LAS) specification, is being widely used to evaluate the ability of an asphalt binder to resist fatigue. The LAS method, although mechanistic in its approach, has certain …

Loss Of Buffer Value Due To Aquifer Depletion: The Case Of High Plains Aquifer, Mani Rouhi Rad, Timothy Foster, Nicholas Brozovic

Daugherty Water for Food Global Institute: Faculty Publications

Existing literature in economics and engineering do not realistically capture the effects of aquifer depletion on loss of profits from agricultural production. While the former literature ignores the physical characteristics of aquifer and the relationship between aquifer levels and groundwater availability, the latter strand of literature does not consider farmers' decisionmaking as a result of aquifer depletion. Misspecification of these relationships and their effect on irrigation decisions can result in misunderstanding the consequences of aquifer depletion and may provide ineffective policies. This paper provides a framework to study the effects of aquifer depletion on the profit of agricultural production. We …

How Governmental Greenhouse Gas Science Has Been Weathered Through Time And Why It Matters, Christopher Apple

STAR Program Research Presentations

Global consumption of materials and energy is accelerating. The rate of plant and animal species extinction is accelerating. On a finite Earth with a growing population, current consumption cannot continue sustainably. Greenhouse gases (GHGs) tell us an important part of this story. The Global Greenhouse Gas Reference Network, managed by scientists at NOAA’s Earth System Research Laboratory, is the largest greenhouse gas analysis network in the world. It has been shaped by scientific questions, stagnant funding despite rises in research costs, and the task of understanding how the Earth system will respond to a changing climate. The Network began by …

Soil-Structure Interaction Effects On The Seismic Response Of Low-Rise Eccentrically Braced Frames, Luis Gerardo Buitrago Goyez

Graduate Theses and Dissertations

The importance of soil-structure interaction (SSI) effects on the seismic response of buildings has been long recognized and has been researched for over 40 years. However, SSI analysis has only been applied in a few building projects because the fixed base condition is considered to provide a conservative estimation for the response of buildings under seismic loads. This assumption of a fixed base condition adopted by practitioners is not always conservative or cost-effective, especially for rigid buildings over soft soils. Additionally, for the case of ductile steel frames with eccentric configurations, the influence of SSI on their seismic performance has …

Laboratory Resistivity Measurements For Soil Characterization, Behdad Mofarraj Kouchaki

Graduate Theses and Dissertations

Field based electrical resistivity measurements, such as electrical resistivity tomography (ERT) and capacitively coupled resistivity (CCR), are geophysical methods that offer a non-destructive and rapid means to collect continuous data. As such, ERT and CCR are becoming increasingly popular tools for geotechnical engineers; however, it is challenging to derive geotechnical information such as soil type, density, and water content from the data. A laboratory geophysical investigation was carried out to gain a better understanding of the parameters that affect the electrical resistivity of soils and devise a relationship between resistivity and soil type or classification. In this study, a soil …

Development Of Deep Site Specific And Reference Shear Wave Velocity Profiles In The Canterbury Plains, New Zealand, Michael Ryan Deschenes

Graduate Theses and Dissertations

Deep (typically >1000 m) shear wave velocity profiles were developed across the Canterbury basin at nine strong motion stations using a combination of active and passive surface wave methods and horizontal to vertical spectral ratio measurements. A multi-mode, multi-method joint inversion process, which included Rayleigh and Love wave dispersion and horizontal to vertical spectral ratio data, was used to estimate the shear wave velocity profiles at each site. A-priori geologic information was utilized in defining preliminary constraints on the complex geologic layering of the Canterbury basin. At sites where interbedded layers were present, velocity reversals were considered in the inversion. …

Geophysical Assessment Of Kinion Lake Dam, Tim Allen Moody

Graduate Theses and Dissertations

Geophysical methods including Capacitively-Coupled Resistivity (CCR), Electrical Resistivity Tomography/Imaging (ERT/ERI), Multichannel Analysis of Surface Waves (MASW) with Love and Rayleigh waves and a Full-Waveform Inversion (FWI) were performed on Kinion Lake Dam, an earth-filled embankment dam that has historically experienced significant seepage and internal erosion issues. Surveys were completed along the crest and downstream toe of the dam. Results from the surveys indicate that each method is capable of resolving the bedrock depth within 1-2 m of locations shown on previous drilling logs, though some discrepancies between the methods exist. A weathered bedrock layer is believed to have led to …

Mitigation And Evaluation Of Alkali-Silica Reaction (Asr) And Freezing And Thawing In Concrete Transportation Structures, Richard Albert Deschenes Jr.

Graduate Theses and Dissertations

An evaluation of alkali-silica reaction (ASR) and freezing and thawing (F/T) in concrete transportation structures is presented along with mitigation methods for slowing the rate of deterioration in concrete. A combination of field and laboratory testing confirms ASR deterioration is exacerbated by exposure to F/T. Laboratory testing indicates an aggregate previously deemed inert to ASR, caused ASR deterioration in several concrete pavement and transportation structures. Existing standard test methods deem this aggregate safe for use in concrete. A modified test method shows the concrete can deteriorate rapidly when subjected to cycles of conditions promoting ASR and F/T. Several structures containing …

Optimization Of Concrete Mixtures For Use In Structural Elements, Waleed Almutairi

Graduate Theses and Dissertations

Portland cement is an essential ingredient in concrete. The use of cement is to enhance the strength as well as other hardened properties of concrete mixtures. Determining the accurate amount of cement is important because the required strength may not be achieved if not enough cement is used. By contrast, when using too much cement, concrete cracking may occur that leads to reducing durability. Researchers at the University of Arkansas (UA) have shown that many bridge decks achieve their 28 day design strength of 4000 psi by 7 days of age. Bridge decks having high strength may experience cracking, which …

Conditional Bias-Penalized Kalman Filter For Improved Estimation And Prediction Of Extremes, Miah Mohammad Saifuddin

Civil Engineering Theses - Archive

Kalman filter (KF) and its variants are widely used for real-time updating of model states and prediction in environmental sciences and engineering. Whereas in many applications the most important performance criteria may be the fraction of the times when the filter performs satisfactorily under different conditions, in many other applications the performance for estimation and prediction of extremes, such as floods, droughts, algal blooms, etc., may be of primary importance. Because KF is essentially a least squares solution, it is subject to conditional biases (CB) which arise from the error-in-variable, attenuation, effects when the model dynamics are highly uncertain, the …

Hydrocarbon Pool Fire Performance Of Reinforced Elastomeric Bearing Pads, Shashank Malal

Civil Engineering Theses - Archive

Bearing pads are used as support for bridge girders to transfer the reaction forces to the substructure. They are designed to accommodate high axial loads from girder, shear deformations due to lateral thermal expansion of girder, and rotational deformation. Apart from these deformations bearing pads may also be subjected to thermal stresses due to daily temperature variations and extreme events like fire hazard. Current design methods do not account for these thermally induced stresses in elastomeric bearing pads. The objective of this research is to study the hydrocarbon pool fire performance of elastomeric bearing pad. This research has three parts. …

Investigation And Proposed Remedy Of Vibration Problem In Industrial Crane System Due To Human Operation, Dustin C. Lorance

Civil Engineering Theses - Archive

A recent investigation of a crane system began when a facilities manager reported a runway beam under-going torsional vibration during operations. The investigation revealed the runway beam’s twisting was caused by resonance vibration due to “inching” of the crane hoist. A Fourier spectrum analysis revealed that one of the harmonic frequencies of this rhythmical motion coincided very close to the natural frequency of the crane system. The runway beam, although met strength requirements, failed to meet serviceability criteria due to the resonance vibration. Resonance vibration issues due to human activity in crane operation (inching, sway, etc.) is often encountered by …

Performance Of Lime- And Cement- Based Treatments Of Sulfate-Rich Soil Via Rc Testing, Azadeh Asghariastaneh

Civil Engineering Theses - Archive

Chemical treatment of expansive sulfate-rich soils, particularly lime- and cement-based methods, had been rather popular due to their relatively low cost and ready availability. However, over the last few decades, extensively documented pavement failures, mainly caused by excessive heaving and/or shrinkage of lime- and cement-treated subgrades with moderate-to-high sulfate content, have led to thorough investigations to assess the actual feasibility and effectiveness of calcium based stabilizers in sulfate-rich soils. Studies have concluded, with solid experimental evidence, that the calcium present in the chemical stabilizers react with the sulfate and alumina of the treated soil to form Ettringite, an expansive mineral …

Crack Healing In 304l Stainless Steel Using Additive Manufacturing And Friction Stir Processing (Fsp), Cameron Scott Gygi

Theses and Dissertations

Continuing an investigation on using FSP to heal stress corrosion cracks (SCC) in welds on nuclear reactors, this study seeks to use AM in addition to FSP to aid crack repair. Previous studies address that current repair technology on nuclear reactors involves the use of TIG welding which can allow helium atoms to aggregate and form voids at the grain boundaries. This weakens the material and renders the repair ineffective. Another previous study evaluated the effectiveness of FSP alone in repairing SCC which did have defects depending on the parameters used during FSP. This study evaluated the use of AM …

Making Public Health Performance Measures For Transportation Accessible To Practitioners, Ziaur Rahman

Civil Engineering Dissertations - Archive

Pollutants emitted into the atmosphere from static and mobile sources pose a threat to human health. The detrimental impact associated with air pollution varies by the type of pollutant, the magnitude, frequency and duration of exposure, and the associated toxicity. While stationary sources play an important role in air pollution, motor vehicle exhaust emissions represent the single largest source of regional air pollution in urban areas. Moreover, outdoor physical activity requires an increased oxygen level with an increase in exercise intensity. Research has shown that both the ventilation and deposition fractions increase significantly during outdoor activities, which may lead to …