Engineering Commons^™

Study Of Water Permeability Of Lightweight Concrete, Xiaoxiao Xu, Haibin Yang, Hongzhi Cui, Zitao Lin, Tommy Yiu Lo

International Conference on Durability of Concrete Structures

The relationship between water permeability and different levels of the tested layers from the top surface to the bottom surface of the lightweight concrete specimens is determined in this study. It is beneficial to develop the design criteria for a durable lightweight concrete. The water permeability coefficient K of the samples was determined by water permeability test using GWT. It is found that the water permeability coefficient K of the three layers in each set of samples tends to decrease as the level of the tested from the top surface increase. Larger Rebound Number and higher density in the bottom …

Influence Of Sio2@Pmhs On The Water Absorption Of Cement Mortar As A Surface Treatment Agent, Ran Li, Pengkun Hou, Zonghui Zhou, Xin Cheng

International Conference on Durability of Concrete Structures

In this paper, the core–shell structured SiO₂@PMHS hybrid nanoparticles were synthesized with tetraethoxysilane (TEOS) and polymethylhydrosiloxane (PMHS). And SiO₂@PMHS core–shell nanoparticles were first used as a surface treatment agent for cement-based materials. The influence of SiO₂@PMHS nanoparticles on the water absorption of hardened cement mortar with water-to-cement ratio of 0.6 was investigated. Results showed that the water absorption of cement mortar treated with SiO₂@PMHS nanoparticles was decreased by 93.47% in comparison to the control sample.

Edge Detection Of Concrete Mesostructure Based On Dis Operator, Bin Feng, Zicheng Xu, Jin Xia, Shijie Jin, Weiliang Jin

International Conference on Durability of Concrete Structures

Aggregate edge detection is the basis of creating concrete mesoscale model, which is applied to analyze concrete mesoscale characteristics. A concrete digital image edge detection method using DIS operator is presented in this paper. Mean filter, multi-scale filter, and Gaussian filter are compared on the effect of concrete image noise reduction. Based on the result, Gaussian filter is the most optimum method to reduce image noise and remain aggregate edge distinct. Sobel operator, Laplacian operator, and DIS operator are applied respectively to detect the aggregate edge on Gaussian filter processed images. Based on the experiment, DIS operator outperforms other two …

Influence Of The Surface Treatment Of Hardened Cement Mortar With Colloidal Nano-Silica And Teos, Pengkun Hou, Xin Cheng, Zonghui Zhou

International Conference on Durability of Concrete Structures

Two types of silicate material, tetraethoxysilane (TEOS) and colloidal nanoSiO2 (CNS), were applied for surface treatment of hardened cement mortar by exploring their filling and pozzolanic reactivity to make the surface compacter. Results showed that the water adsorption coefficient, the water vapor transmission rate, and the water penetration depth were reduced when CNS and TEOS were applied onto the surface of hardened cement mortar, and TEOS exhibits a superior effect on surface treatment, making the mass-transport rate and extent smaller than CNS does.

Performance Of Concrete Patch Repairs: From A Durability Point Of View, Choorackal Avirachan Eldho, Ominda Nanayakkar, Jun Xia, Steve Jones

International Conference on Durability of Concrete Structures

Chloride contamination in reinforced concrete leads to the corrosion of steel bars. Concrete patch repairs are widely practiced as a remedial measure for the mitigation of such corrosion in reinforced concrete structures. The performance of the patch repairs was studied by various researchers in the past. The structural and material aspects of patch repairs have received more attention than the electrochemical consequences of patch repairs in past studies. But electrochemical changes could be the underlying cause for the failure of many patch repairs. This paper reviews the performance of patch repairs from a durability point of view. It covers the …

Aggregate Shape Effect On Multicomponent Ionic Electromigration In Concrete, Qing-Feng Liu, Long-Yuan Li, Jian Yang

International Conference on Durability of Concrete Structures

This paper presents a numerical study on the mechanism of chloride migration in concrete. Unlike most of existing work, this study utilises multicomponent ionic transport models to reflect the influence of ionic interactions by coupling both mass conservation and Poisson’s equations. A series of 2-D, 3-phase models with different shapes and volume fractions of aggregates are developed to simulate the chloride migration test. Through a comparatively overall numerical exploration that considers external voltage, ionic interactions, heterogeneous nature, ITZ, and ionic binding, some important features about multispecies coupling and aggregate shape effect, which have not been properly reported from existing concrete …

Effectiveness Of Vacuum Saturation Preconditioning Regime For Assessing Water Permeability Of High Performance Concrete, Kai Yang, Muhammed Basheer, Changhui Yang, Yun Bai, Adrian Long

International Conference on Durability of Concrete Structures

Saturating high performance concrete (HPC) for assessing water permeability is a challenge. This paper reports a testing program established to determine the reliability and efficiency of an in situ preconditioning regime, the vacuum saturation, for the water permeability test. The vacuum saturation regime was examined through changing the parameters used and to justify if the field conditioning regime is able to yield similar results as in the laboratory, the results after vacuum saturation were statistically analysed and compared with that after incremental immersion. Its accuracy was further examined by additional experiments, whereas factors considered include different concrete mixes and different …

Research On Chloride Penetration Resistance Of Hybrid Fiber Reinforced Self-Compacting Concrete, Wu-Jian Long, Zhe-Ming Mai, Jin-Guang Shi, Tian-Tian Zhao, Wu-Lei Peng

International Conference on Durability of Concrete Structures

The properties of chloride penetration of hybrid fiber reinforced self-compacting concrete (SCC) were investigated in this study. The results show that, the chloride penetration resistance of concrete can be improved by single incorporation either carbon or cellulose fibers. The concrete chloride diffusion coefficient D_RCM of 12-cm length carbon SCC with fiber content of 1.7 kg/m³, 2.72 kg/m³, and 3.4 kg/m³ decreases by 10.3%, 25.5%, and 18.2% compared to reference concrete without any fibers, respectively. Moreover, the concrete chloride diffusion coefficient D_RCM of cellulose SCC with fiber content of 1.2 kg/m³, 1.6 …

Corrosion Of Steel In Concrete And Its Prevention In Aggressive Chloride-Bearing Environments, Luca Bertolini, Maddalena Carsana, Matteo Gastaldi, Federica Lollini, Elena Redaelli

International Conference on Durability of Concrete Structures

This keynote paper deals with the durability of reinforced concrete (RC) structures exposed to aggressive environments characterized by high concentration of chloride ions, namely, marine environments or the use of de-icing salts. The mechanism of chloride-induced corrosion of steel in concrete is introduced, and its influence on the service life of RC structures is analyzed. Factors affecting the time to corrosion initiation are described with regard to both concrete properties and environmental exposure conditions. Design approaches available for achieving durability targets associated with the design service life are analyzed, focusing on studies carried out by the authors in recent years …

Moisture And Temperature Effects On Interface Mechanical Properties For External Bonding, Tamon Ueda, Justin Shrestha, Khuram Rashid, Dawei Zhang

International Conference on Durability of Concrete Structures

In order to develop rational guidelines for strengthening by external bonding, it is necessary to clarify longterm performance of interfacial bonding property. In this paper, moisture effects on bonding properties at FRP–concrete interface and temperature/moisture effects on bonding properties at PCM–concrete interface are presented. Shear bond strength of FRP–concrete interface is affected by moisture because resin–concrete adhesion strength is affected by moisture. Among tested CFRP external bonding systems, wet-layup CFRP systems all show the strength reduction, while prefabricated CFRP systems all show the strength increase after immersion. The bond stress–slip relationship and interfacial fracture energy also change, which can explain …

Seafloor Visual Saliency Evaluation For Navigation With Bow And Dbscan, Yue Geng, Zhiyuan Wang, Congcong Shi, Rui Nian, Cheng Zhang, Bo He, Yue Shen, Amaury Lendasse

Engineering Management and Systems Engineering Faculty Research & Creative Works

In This Paper, We Try to Combine Bag-Of-Words (Bow) with Density-Based Spatial Clustering of Applications with Noise (DBSCAN) Together for One Kind of Sparse Representation in the Seafloor Visual Saliency Evaluation. Properties in the Water, Due to the Large Amount of Acoustic Noises, Sonar Signals Are Easily Polluted and Interfered during Image Collection, and the Sonar Images Usually Diverge from the True Underwater Environment or Degrade the Accuracy of the Measure, So Sparse Representation Has Been Taken into Consideration for Underwater Sonar Image Visual Saliency Evaluation. Our Method is a Simple and Computationally Efficient Extension of an Order less Bow …

Underwater Object Detection With Efficient Shadow-Removal For Side Scan Sonar Images, Ruijie Chang, Yaomin Wang, Jiaru Hou, Shuqi Qiu, Rui Nian, Bo He, Amaury Lendasse

Engineering Management and Systems Engineering Faculty Research & Creative Works

Side Scan Sonar Has Been Widely Used in Ocean Investigations, Underwater Object Detection by Side Scan Sonar is One of the Most Essential and Fundamental Tasks These Years. in This Paper, We Present One Simplified Underwater Object Detection Scheme with the Help of Shadow Removal of Side Scan Sonar Images. the Fuzzy C-Mean Clustering (FCM) Algorithm is First Taken to Partition All Pixels from the Side Scan Sonar Images into a Collection of C Fuzzy Clusters, Which Makes Shadow Regions Be Segmented. the Criminisi Algorithm based on Isophote-Driven Image Sampling Process is Then Made Full Use of to Undertake the …

Eigenstress Model For Electrochemistry Of Solid Surfaces, Hongxin Ma, Xilin Xiong, Panpan Gao, Xi Li, Yu Yan, Alex A. Volinsky, Yanjing Su

Mechanical Engineering Faculty Publications

Thermodynamic analysis and molecular dynamics simulations were conducted to systematically study the size-dependent electrochemical response of solids. By combining the generalized Young-Laplace equation with the popular Butler-Volmer formulation, the direct influence of surface stress on solid film electrochemical reactions was isolated. A series of thermodynamic formulas were developed to describe the size-dependent electrochemical properties of the solid surface. These formulas include intrinsic surface elastic parameters, such as surface eigenstress and surface elastic modulus. Metallic films of Au, Pt, Ni, Cu and Fe were studied as examples. The anodic current density of the metal film increased, while the equilibrium potential decreased …

Pursuing Vision Zero In Seattle – Results Of A Systemic Safety Analysis, Rebecca Sanders

PSU Transportation Seminars

Many cities are considering pursuing Vision Zero to eliminate traffic deaths, but may not know how to move beyond addressing past crash locations toward preventing future crashes. Systemic analysis, which looks at crash patterns to determine common characteristics associated with various types of crashes, shows promise in helping cities to identify problematic locations and treatments in the hopes of preventing future crashes.

This presentation will share results from part of Seattle’s Vision Zero effort – a multi-phased analysis of pedestrian and bicycle crash data aiming to help the City understand both where crashes have occurred and where they are most …

The Design, Fabrication And Characterization Of Integrated Photoconductive Antennas For On-Chip Terahertz Wave Radiation And Detection, Ruben Dario Velasquez Rios

Dissertations, Theses, and Capstone Projects

Terahertz (THz) wave (between 0.1 and 10 THz) is attracting a lot of attention due to its unique properties that are favorable to various applications. These include non-ionizing radiation, better resolution than a microwave, unique spectral absorption, and an ability to propagate through many types of materials. It has been intensively researched in sensing and imaging technology for a wide range of applications in areas such as biology, pharmaceutical, food and drug control, medical science, and security screening. Driven by mostly scientific research interests, the majority of THz systems are more focused on system performance rather than system size, integration, …

Mums: Mobile Urinalysis For Maternal Screening, Blair Koeneman, Amy Miller, Joe Neumeyer, Jake Prince

Interdisciplinary Design Senior Theses

Pregnant women in low-income communities often lack access to the necessary healthcare for successful births. This is frequently due to the high costs of medical care, the remote location of patients, and the infrequency of primary care medical visits. To address this inequity, we have created a mobile application and imaging unit that allows for the low-cost implementation of urinalysis testing, which will aid in the detection of warning signs for prenatal health risks. From a single photo taken with a tablet camera, our application digitizes the results of a standard urinalysis test strip, displays the test results, and tracks …

Underwater 3d Object Reconstruction With Multiple Views In Video Stream Via Structure From Motion, Xiao Xu, Renzheng Che, Rui Nian, Bo He, Meimei Chen, Amaury Lendasse

Engineering Management and Systems Engineering Faculty Research & Creative Works

Underwater 3d Object Reconstruction is One of the Most Essential and Fundamental Tasks in Ocean Investigations. in This Paper, We Try to Capture the Inherent Geometrical Variation of 3d Objects at Multiple Visual Angels with the Underwater Vehicles and Develop a Novel Underwater 3d Object Reconstruction Model for the Continuous Video Stream. Image Enhancement Will Be First Taken into Consideration by Guided Image Filtering to Acquire Clearer Images for Object Tracking Which Can Be Completed by the Particle Filter. and Then, We Use Scale Invariant Feature Transform (Sift) and Random Sample Consensus (Ransac) to Detect and Correspond the Features of …

Scale Up Bayesian Network Learning, Xiannian Fan

Dissertations, Theses, and Capstone Projects

Bayesian networks are widely used graphical models which represent uncertain relations between the random variables in a domain compactly and intuitively. The first step of applying Bayesian networks to real-word problems is typically building the network structure. Optimal structure learning via score-and-search has become an active research topic in recent years. In this context, a scoring function is used to measure the goodness of fit of a structure to given data, and the goal is to find the structure which optimizes the scoring function. The problem has been viewed as a shortest path problem, and has been shown to be …

Vector Beams For Fundamental Physics And Applications, Giovanni Milione

Dissertations, Theses, and Capstone Projects

Lights salient degrees of freedom are the independent parameters that completely de- scribe an electromagnetic wave (in the paraxial approximation) and include polarization, wavelength, and time. Most recently, lights space degree of freedom has received sig- nificant attention via the sub-discipline of optics that can be referred to as complex light or structured light. The study of complex light is a veritable renaissance of optics; us- ing lights space degree of freedom many classical optics phenomena have been revisited with novel results. In this thesis, a novel form of structured light referred to as vector beams will be investigated. It …

Relationship Between Electrochemical Reaction Processes And Environment-Assisted Crack Growth Under Static And Dynamic Atmospheric Conditions, Fritz Friedersdorf, Carlos Hangarter, Nate Brown, Steve Policastro, Matt Merrill

International Workshop on the Environmental Damage in Structural Materials Under Static Load/Cyclic Loads at Ambient Temperatures

Environment-assisted cracking (EAC) of aluminum alloys in corrosive atmospheres is an important maintenance and safety issue for aerospace structures. EAC initiation and propagation are influenced by the interaction of load, environment, and alloy properties. For atmospheric corrosion, environmental conditions are dynamic; where temperature, relative humidity, and surface contaminants interact to control thin film electrolyte properties. Recent studies have determined that stage II stress corrosion crack (SCC) propagation, under atmospheric conditions is strongly dependent on humidity. SCC propagation in AA5083 and AA7075 alloys is a maximum during drying processes at intermediate humidity levels at or below the deliquescence relative humidity (DRH) …

Planly, Alberto Diaz-Tostado, Amy Nguyen Tran

Computer Science and Engineering Senior Theses

Individuals currently live in a society that revolves around productivity. People from managers to students are bombarded with numerous tasks and daunting deadlines, making it extremely difficult to stay organized. In addition, these individuals also have multiple commitments in their lives, adding to the stress of keeping up with their already busy schedules. Currently, people are faced with a variety of organization methods. However, the two tools most people resort to, e-mail and notepad, have become more burdensome than helpful as the organization challenges have increased. In addition, current project management solutions are targeted towards large enterprises and not accessible …

Investigation Of Electrochemically-Induced Repassivation Of Al 7075-T6 And Al 2024-T3 As A Function Of Applied Stress And Galvanic Corrosion, Monica Trueba, Stefano P. Trasatti, Daniele Guastaferro, Michele Ferri, Marina Cabrini

International Workshop on the Environmental Damage in Structural Materials Under Static Load/Cyclic Loads at Ambient Temperatures

The repassivation behavior of Al alloys 7075-T6 and 2024-T3 was investigated by means of pitting scan (PS) technique (Fig. 1) (Trueba, Trasatti, 2015). The effect of mechanical load and galvanic coupling was estimated by considering principally the electrochemical characteristics of the reverse curve, namely the pit transition potential (Eptp), the associated current density (iptp) and the steepness. The load levels explored were mostly below the elastic limit, using four point bent-beam (4PBB) stress-corrosion test specimens (ASTM G39-99). CRES 304 or Ti6Al4V alloy were physically joined with Al sheet for simulating stress-induced galvanic corrosion. Different experimental variables (e.g. irev, [Cl-], pH, …

Examination And Prediction Of Corrosion Fatigue Damage And Inhibition, Sarah E Galyon Dorman, Justin W Rausch, Saravanan Arunachalam, Scott A Fawaz

International Workshop on the Environmental Damage in Structural Materials Under Static Load/Cyclic Loads at Ambient Temperatures

The United States Department of Defense (DoD) estimated that the annual cost of corrosion, the unintended material degradation due to the environment, to weapon systems and infrastructure in 2010 exceeded $21 billion, and that the number was likely to continue to rise. Unfortunately, as the warfighters demand more from their systems, corrosion prevention and control is frequently traded during the acquisition cycle for weapon system performance. As a result, the DoD remains entrenched in a find-and-fix corrosion management philosophy which is expensive and unsustainable. Better standardized fatigue laboratory procedures are need to help the DoD develop (1) a fundamental understanding …

Chaotic Advection-Driven Mixing In Unsteady Three-Dimensional Mhd Flows In Microfluidic Devices, Fangping Yuan, Kakkattukuzhy M. Isaac

Collaborative Research: Actively Controllable Microfluidics with Film-Confined Redox-Magnetohydrodynamics -- Video and Data

No abstract provided.

Understanding Small Crack Effects On Failure & Threshold Diagrams, Daniel Kujawski

International Workshop on the Environmental Damage in Structural Materials Under Static Load/Cyclic Loads at Ambient Temperatures

It is well recognized that crack length has significant effects on both the monotonic failure stress and cyclic threshold stress conditions. Existing experimental data indicates that LEFM predicts correctly the failure and threshold stresses only for relatively long cracks. For small/short cracks, the LEFM overestimates both the failure and threshold stresses. Usually, an argument has been made that LEFM is violated in terms of a crack length with respect to the crack-tip plastic zone that results in overestimating the failure stress for small cracks. On the other hand, the Kitagawa diagram has been used to experimentally illustrate the connection between …

Cee Team Won Weau Competition | Civil And Environmental Engineering, Usu College Of Engineering

College of Engineering News

A team from USU competed against local university in Utah and won the annual Water and Environment Federation of Utah (WEAU) Student Design Competition on Friday April 29 in St. George.

Large Length Scale Capillary Fluidics: From Jumping Bubbles To Drinking In Space, Andrew Paul Wollman

Dissertations and Theses

In orbit, finding the "bottom" of your coffee cup is a non-trivial task. Subtle forces often masked by gravity influence the containment and transport of fluids aboard spacecraft, often in surprising non-intuitive ways. Terrestrial experience with capillary forces is typically relegated to the micro-scale, but engineering community exposure to large length scale capillary fluidics critical to spacecraft fluid management design is low indeed. Low-cost drop towers and fast-to-flight International Space Station (ISS) experiments are increasing designer exposure to this fresh field of study. This work first provides a wide variety of drop tower tests that demonstrate fundamental and applied capillary …

Aqueous Photochemistry Of Glyoxylic Acid, Alexis J. Eugene, Sha-Sha Xia, Marcelo I. Guzman

Chemistry Faculty Publications

Aerosols affect climate change, the energy balance of the atmosphere, and public health due to their variable chemical composition, size, and shape. While the formation of secondary organic aerosols (SOA) from gas phase precursors is relatively well understood, studying aqueous chemical reactions contributing to the total SOA budget is the current focus of major attention. Field measurements have revealed that mono-, di-, and oxo-carboxylic acids are abundant species present in SOA and atmospheric waters. This work explores the fate of one of these 2-oxocarboxylic acids, glyoxylic acid, which can photogenerate reactive species under solar irradiation. Additionally, the dark thermal aging …

Aircraft Cyber Security And Information Exchange Safety Analysis For Department Of Commerce, Timothy B. Holt, Mohammad Moallemi, Linda Weiland, Matt Earnhardt, Sonya Mcmullen

Publications

The Federal Aviation Administration’s (FAA) Next Generation Air Transportation (NextGen) program is a long-term modernization and transformation of the current National Airspace System (NAS) into a more effective and coordinated decision-making system. NextGen provides a more reliable, secure, and dependable aviation capability for both users and operators ensuring more capacity, throughput, and safety. This research delineates a high-level Safety Risk Assessment (SRA) related to NextGen technologies, specifically Aircraft Communications Addressing and Reporting System (ACARS) as well as Aircraft Access to System Wide Information Management (SWIM) network (AAtS). Other communication mediums such as Mode-S or ADS-B transponder are also data exchange …

X-Ray Characterization Of Mesophases Of Human Telomeric G-Quadruplexes And Other Dna Analogues, Jacob B. Schimelman, Nicole F. Steinmetz, Roger H. French

Faculty Scholarship

Observed in the folds of guanine-rich oligonucleotides, non-canonical G-quadruplex structures are based on G-quartets formed by hydrogen bonding and cation-coordination of guanosines. In dilute 5′-guanosine monophosphate (GMP) solutions, G-quartets form by the self-assembly of four GMP nucleotides. We use x-ray diffraction to characterize the columnar liquid-crystalline mesophases in concentrated solutions of various model G-quadruplexes. We then probe the transitions between mesophases by varying the PEG solution osmotic pressure, thus mimicking in vivo molecular crowding conditions. Using the GMP-quadruplex, built by the stacking of G-quartets with no covalent linking between them, as the baseline, we report the liquid-crystalline phase behaviors of …