Digital Commons Network^™

Ionization Study Of Isomeric Molecules In Strong-Field Laser Pulses, Stefan Zigo, Anh-Thu Le, Pratap Timilsina, Carlos A. Trallero-Herrero

Physics Faculty Research & Creative Works

Through the use of the technique of time-of-flight mass spectroscopy, we obtain strong-field ionization yields for randomly oriented 1,2-dichloroethylene (1,2-DCE) (C₂H₂Cl₂) and 2-butene (C₄H₈). We are interested in studying the effect of conformal structure in strong-field ionization and, in particular, the role of molecular polarity. That is, we can perform strong-field ionization studies in polar vs non-polar molecules that have the same chemical composition. We report our findings through the ionization yields and the ratio (trans/cis) of each stereoisomer pair as a function of intensity.

Work Zone Simulator Analysis: Driver Performance And Acceptance Of Missouri Alternate Lane Shift Configurations, Suzanna Long, Ruwen Qin, Dincer Konur, Ming-Chuan Leu, S. Moradpour, S. Thind, H. Nadathur

Engineering Management and Systems Engineering Faculty Research & Creative Works

The objective of this project is to evaluate MoDOT’s alternate lane shift sign configuration for work zones. The single signproposed by MoDOT provides the traveler with enough information to let them know that all lanes are available to shift around thework zone, whereas the MUTCD signs require drivers to see two signs. This research simulation project evaluates the drivers’ laneshifting performance and acceptance of the alternate lane shift sign proposed by MoDOT to be used on work zones as compared tothe MUTCD lane shift signs. Based on the study results, no difference was observed between MUTCD lane shift sign andMoDOT …

Record: Temporarily Randomized Encoding Of Combinational Logic For Resistance To Data Leakage From Hardware Trojan, Travis E. Schulze, Kevin Kwiat, Charles Kamhoua, Shih Chieh Chang, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

Many design companies have gone fabless and rely on external fabrication facilities to produce chips due to increasing cost of semiconductor manufacturing. However, not all of these facilities can be considered trustworthy; some may inject hardware Trojans and jeopardize the security of the system. One common objective of hardware Trojans is to a establish side channel for data leakage. While extensive literature exists on various defensive measures, almost all of them focus on preventing the establishment of side channels and can be compromised if attackers gain access to the physical chip and can perform reverse engineering between multiple fabrication runs. …

Experimental Study On System Reliability Of Cold-Formed Steel Roof Trusses, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

This report presents a research project aimed at advancing the treatment of cold-formed steel (CFS) structural reliability in roof trusses. Structural design today relies almost exclusively on component-level design; so, structural safety is assured by limiting the probability of failure of individual components. Reliability of the entire system is typically not assessed, so in a worst-case scenario the system reliability may be less than the component reliability, or in a best-case scenario the system reliability may be much greater than the component reliability. A roof truss itself, is a subsystem with several possible failure modes that are being studied in …

The Use Of Geophysical Methods For Dam Seepage Investigations And Dredged Oyster Deposit Characterization, Stanley Chinedu Nwokebuihe

Doctoral Dissertations

"The dissertation is made up of three papers, which discuss the utility of geophysical tools in earthfill dam investigations and dredged oyster bed characterization.

In the first paper, an earthfill dam in Warren County, Missouri was effectively investigated for seepage through the dam and its outlet works using an integration of the electrical resistivity tomography, induced polarization and spontaneous potential geophysical tools. Recommendations were subsequently made based on the results of the study on grout locations to prevent further seepage. In the second paper, a similar study of earthfill dam seepage was conducted on a different dam in Southern Missouri. …

Successful Field Application Of A New Polymer Flooding Technique Suitable For Mature Oilfields Against Low-Oil-Price Background - A Case Study From East China, X. Wu, Y. Wu, C. Xiong, H. Xu, X. Jia, L. Shao, Y. Xiong, J. Zhang, A. Wang, H. Xu, J. Tian, Baojun Bai, X. Tian

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

DGXJ is a sandstone reservoir with temperature of 113 °C, salinity of 36235mg/L, and calcium and magnesium content of 1152mg/L and 30mg/L respectively. The reservoir is not only vertically multilayered and severe heterogeneous, but also witnesses water flowing channels, irregular and imperfect injecting production well patterns, high recovery degree (43%) and high water cut (97%). A new particle-type polymer (SMG) slug combined several small linked-polymer-gel (LPG)slugs and pregelled swellable particle (PSP) was applied during 2011-2015 and achieved remarkable technical and economic effect. The application area is composed of 16 injection wells and 22 production wells. Among the 22 wells, 17 …

Contributing Factors To Child Stunting In Guatemala: A Systems Analysis Focused On Enteric Disease Transmission And Mycotoxin Exposure, Lee Emerson Voth-Gaeddert

Doctoral Dissertations

"Child stunting -- low height-for-age -- is a United Nation's indicator for chronic malnutrition that has been linked to both acute and chronic health problems. Data from Guatemala suggests for children under five years of age, 49% are classified as stunted. This dissertation tests the following hypotheses, among children in Guatemala 1) environmental enteric dysfunction (EED) is correlated with height-for-age, 2) aflatoxin B (AFB) exposure is correlated with height-for-age, and 3) AFB exposure is correlated with EED. A network analysis was conducted on data from the US Agency for International Development (USAID) collected in 2012 to identify trends in a …

Randomized Encoding Of Combinational And Sequential Logic For Resistance To Hardware Trojans, Travis Edward Schulze

Doctoral Dissertations

"Globalization of micro-chip fabrication has opened a new avenue of cyber-crime. It is now possible to insert hardware Trojans directly into a chip during the manufacturing process. These hardware Trojans are capable of destroying a chip, reducing performance or even capturing sensitive data. To date, defensive methods have focused on detection of the Trojan circuitry or prevention through design for security methods.

This dissertation presents a shift away from prevention and detection to a design methodology wherein one no longer cares if a Trojan is present or not. The Randomized Encoding of Combinational Logic for Resistance to Data Leakage or …

A Functional Data Analytic Approach For Region Level Differential Dna Methylation Detection, Mohamed Salem F. Milad

Doctoral Dissertations

"DNA methylation is an epigenetic modification that can alter gene expression without a DNA sequence change. The role of DNA methylation in biological processes and human health is important to understand, with many studies identifying associations between specific methylation patterns and diseases such as cancer. In mammals, DNA methylation almost always occurs when a methyl group attaches to a cytosine followed by a guanine (i.e. CpG dinucleotides) on the DNA sequence. Many statistical methods have been developed to test for a difference in DNA methylation levels between groups (e.g. healthy vs disease) at individual cytosines. Site level testing is often …

Privacy Setting Recommendation For Image Sharing, Jun Yu, Zhenzhong Kuang, Zhou Yu, Dan Lin, Jianping Fan

Computer Science Faculty Research & Creative Works

This paper aims to simultaneously consider two inseparable issues for privacy setting recommendation: (1) sensitiveness of visual content of the images being shared; and (2) trustworthiness of users being granted. First, an object-based approach is developed for image content sensitiveness (privacy) representation. Secondly, the users on a social network are clustered into a set of representative social groups to generate a discriminative dictionary for user trustworthiness characterization. Finally, a tree classifier is trained hierarchically to recommend appropriate privacy settings for image sharing.

Ior Methods In Unconventional Reservoirs Of North America: Comprehensive Review, Dheiaa Alfarge, Mingzhen Wei, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Unconventional resources have played a significant role in changing oil industry plans recently. Shale formations in North America have huge oil in place, 900 billion barrels of recoverable oil in Bakken only. However, the predicted primary recovery is still low as less than 10%. Therefore, seeking for improved oil techniques to increase oil recovery in these complex plays is inevitable. In this paper, three stages of review have been combined to find out the applicability of the most feasible IOR methods in these unconventional reservoirs. Firstly, the most common fluid and rock properties of these reservoirs have been investigated and …

Selection Criteria For Miscible-Gases To Enhance Oil Recovery In Unconventional Reservoirs Of North America, Dheiaa Alfarge, Mingzhen Wei, Baojun Bai, Mortadha Alsaba

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Unconventional resources have played a significant role in changing oil industry plans recently. Shale formations in North America such as Bakken, Niobrara, and Eagle Ford have huge oil in place, 100-900 billion barrels of oil in Bakken only. However, the predicted primary recovery is still low as 5-10%. Therefore, seeking for techniques to enhance oil recovery in these complex plays is inevitable. In this paper, two different approaches have been integrated to investigate the feasibility of three different miscible gases which are CO₂, lean gases, and rich gases. Firstly, numerical simulation methods of compositional models have been incorporated …

Wellbore Stability Evaluation For Mishrif Formation, Ethar H.K. Alkamil, Husam R. Abbood, Ralph E. Flori, Andreas Eckert

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

During drilling operations for the E oilfield in the Mishrif formation in southern Iraq, stuck pipe has been identified as a significant geomechanical problem for several wells. In this study, a 1-D mechanical earth model (MEM) of the Mishrif formation is compiled based on its state of stress and rock strength parameters and is utilized to assess the contribution of borehole collapse leading to the stuck pipe problems. The MEM model is based on the principal in situ stresses and their orientation obtained from wireline logs measurements, measuring while drilling (MWD), and leak off test (LOT). Rock strength properties are …

Integrating Microgels And Low Salinity Waterflooding To Improve Conformance Control In Fractured Reservoirs, Ali Alhuraishawy, Mingzhen Wei, Baojun Bai, Abdullah Almansour

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The recovery from fractured reservoirs is usually low. The areal heterogeneity is one result of the fractured reservoir. Low salinity waterflooding (LSWF) and preformed particle gel (PPG) have recently investigated by some researchers. The main objective of this study was to determine whether the combining technologies can improve conformance control in fractured sandstone reservoirs. Semi-transparent five-spot models made of sandstone cores and acrylic plates were built. The effect of low salinity waterflooding on oil recovery was studied. Models were designed with three parallel open fractures. Sodium chloride (1.0, 0.1, 0.01, and 0.001 wt. % NaCl) were used for brine flooding …

Effect Of Molecular-Diffusion Mechanisim On Co2 Huff-N-Puff Process In Shale-Oil Reservoirs, Dheiaa Alfarge, Mingzhen Wei, Baojun Bai, Abdullah Almansour

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Unconventional resources have played a significant role in changing oil industry plans recently. Shale formations in North America such as Bakken, Niobrara, and Eagle Ford have huge oil in place, 100-900 billion barrels of recoverable oil in Bakken only. However, the predicted primary recovery is still low as less than 10%. Therefore, seeking for techniques to increase oil recovery in these complex plays is inevitable. In this paper, three different approaches have been combined to investigate the effect of molecular-diffusion mechanism on CO₂ huff-n-puff process in Bakken formation. Firstly, comprehensive review has been conducted on the reported experimental studies …

Novel Environmentally Benign Hydrogel: Nano-Silica Hybrid Hydrolyzed Polyacrylamide/ Polyethyleneimine Gel System For Conformance Improvement In High Temperature High Salinity Reservoir, Liping Ma, Shitou Wang, Yifu Long, Changqian Zhu, Hongbin Yang, Tangying Yang, Xiaochun Liu, Xiaorong Li, Baojun Bai, Wanli Kang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In order to address the conformance problem in high temperature and high salinity/hardness reservoir, an environmentally benign in-situ gel was developed based on hydrolyzed polyacrylamide (HPAM) and polyethyleneimine (PEI). Moreover, silica nanoparticle (SNP) was embedded to improve the performance of HPAM/PEI gel. To achieve the optimum formulation of HPAM/PEI-SNP gel, a comprehensive investigation was first conducted with the respect of gelation time, gel strength, and thermal stability. In addition, the particle size of SNP was determined by Dynamic Light Scatter (DLS) and the microstructure of HPAM/ PEI-SNP gel was characterized via Scanning Electron Microscopy (SEM). The optimum formulation, containing the …

Control Of Single- And Dual-Probe Atomic Force Microscopy, Muthukumaran Loganathan

Doctoral Dissertations

“Atomic force microscope (AFM) is one of the important and versatile tools available in the field of nanotechnology. It is a type of probe-based microscopy wherein an atomically sharp tip, mounted on the free end of a microcantilever, probes the surface of interest to generate 3D topographical images with nanoscale resolution. An integral part of the AFM is the feedback controller that regulates the probe deflection in the presence of surface height changes, enabling the control action to be used for generating topographical image of the sample. Besides sensing, the probe can also be used as a mechanical actuator to …

Survivability Modeling For Cyber-Physical Systems Subject To Data Corruption, Mark James Woodard

Doctoral Dissertations

"Cyber-physical critical infrastructures are created when traditional physical infrastructure is supplemented with advanced monitoring, control, computing, and communication capability. More intelligent decision support and improved efficacy, dependability, and security are expected. Quantitative models and evaluation methods are required for determining the extent to which a cyber-physical infrastructure improves on its physical predecessors. It is essential that these models reflect both cyber and physical aspects of operation and failure. In this dissertation, we propose quantitative models for dependability attributes, in particular, survivability, of cyber-physical systems. Any malfunction or security breach, whether cyber or physical, that causes the system operation to depart …

Aerodynamic Design Of A Rectangular Wing In Subsonic Inviscid Flow By Surrogate-Based Optimization, Xiaosong Du, Anand Amrit, Andrew Thelen, Leifur Leifsson, Yu Zhang, Zhong Hua Han, Slawomir Koziel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The paper presents results of aerodynamic design of a rectangular wing in subsonic inviscid flow using surrogate-based local and global search algorithms. The aerodynamic design problem is formulated in Benchmark Cases 3 and 6 developed by the AIAA Applied Aerodynamics Discussion Group. Both involve lift-constrained drag minimization at a Mach number of 0.5 with relatively low lift coefficients (0.2625 and 0.375) with several nonlinear constraints and a small number design variables (up to 15). In this work, the local search is performed using variable-fidelity modelling and output space mapping, whereas the global search is performed using approximation-based surrogates. The paper …

Aerodynamic Design Of The Rae 2822 In Transonic Viscous Flow: Single- And Multi-Objective Optimization Studies, Anand Amrit, Xiaosong Du, Andrew Thelen, Leifur Leifsson, Slawomir Koziel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper addresses a benchmark aerodynamic design problem proposed by the AIAA Aerodynamic Design Optimization Discussion Group: Drag minimization of the RAE 2822 in transonic viscous flow at a fixed lift coefficient with constraints on the pitching moment coefficient and the cross-sectional area. The single-objective optimization (SOO) problem is solved using surrogate-based optimization (SBO) with the surrogates constructed through output space mapping and variable-resolution Reynolds-Averaged Navier-Stokes computational fluid dynamics models. Improving the implementation of our search algorithms enabled us to obtain the SOO optimal design four times faster than in our prior work in terms of CPU time. To explore …

A New Reinforcement Learning Algorithm With Fixed Exploration For Semi-Markov Decision Processes, Angelo Michael Encapera

Masters Theses

"Artificial intelligence or machine learning techniques are currently being widely applied for solving problems within the field of data analytics. This work presents and demonstrates the use of a new machine learning algorithm for solving semi-Markov decision processes (SMDPs). SMDPs are encountered in the domain of Reinforcement Learning to solve control problems in discrete-event systems. The new algorithm developed here is called iSMART, an acronym for imaging Semi-Markov Average Reward Technique. The algorithm uses a constant exploration rate, unlike its precursor R-SMART, which required exploration decay. The major difference between R-SMART and iSMART is that the latter uses, in addition …

A Bounded Actor-Critic Algorithm For Reinforcement Learning, Ryan Jacob Lawhead

Masters Theses

"This thesis presents a new actor-critic algorithm from the domain of reinforcement learning to solve Markov and semi-Markov decision processes (or problems) in the field of airline revenue management (ARM). The ARM problem is one of control optimization in which a decision-maker must accept or reject a customer based on a requested fare. This thesis focuses on the so-called single-leg version of the ARM problem, which can be cast as a semi-Markov decision process (SMDP). Large-scale Markov decision processes (MDPs) and SMDPs suffer from the curses of dimensionality and modeling, making it difficult to create the transition probability matrices (TPMs) …

St. Louis Area Earthquake Hazards Mapping Project: Seismic And Liquefaction Hazard Maps, Chris H. Cramer, Robert A. Bauer, Jaewon Chung, J. David Rogers, Larry Pierce, Vicki Voigt, Brad Mitchell, David Gaunt, Robert A. Williams, David J. Hoffman, Gregory L. Hempen, Phyllis J. Steckel, Oliver Salz Boyd, Connor M. Watkins, Kathleen B. Tucker, Natasha S. Mccallister

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

We present probabilistic and deterministic seismic and liquefaction hazard maps for the densely populated St. Louis metropolitan area that account for the expected effects of surficial geology on earthquake ground shaking. Hazard calculations were based on a map grid of 0.005°, or about every 500 m, and are thus higher in resolution than any earlier studies. To estimate ground motions at the surface of the model (e.g., site amplification), we used a new detailed near-surface shear-wave velocity model in a 1D equivalent- linear response analysis. When compared with the 2014 U.S. Geological Survey (USGS) National Seismic Hazard Model, which uses …

Analysis Of Ior Pilots In Bakken Formation By Using Numerical Simulation, Dheiaa Alfarge, Mingzhen Wei, Baojun Bai, Mortadha Alsaba

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Bakken is the most productive formation among unconventional plays in North America. This formation has 7.4 billion barrels of recoverable oil. However, the primary oil recovery is still low as 5-10%. Miscible natural gas and carbon dioxide (CO₂) might be the most two potential strategies to improve oil recovery in such complex play. In this study, some of the IOR pilots which have been conducted in Montana, North Dakota, and South Saskatchewan have been presented. The performance results of these pilots in US-Bakken versus Canadian-Bakken have been compared. Moreover, the reasons beyond the successful IOR pilots in Canadian-Bakken …

Optimizing Injector-Producer Spacing For Co2 Injection In Unconventional Reservoirs Of North America, Dheiaa Alfarge, Mingzhen Wei, Baojun Bai, Abdullah Almansour

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Shale oil reservoirs such as Bakken, Niobrara, and Eagle Ford have become the main target for oil and gas investors as conventional formations started to deplete and diminish in number. These reservoirs have a huge oil potential; however, the predicted primary oil recovery is still low as average of 7.5 %. Carbon dioxide (CO₂) flooding has been a controversial approach to increase oil recovery in these poor-quality formations. This study investigated the effect of injector-producer spacing, in range of 925-1664 ft, on CO₂ performance in these plays by using numerical simulation methods. CO₂ utilization value under …

Error Mapping Of Build Volume In Selective Laser Melting, Ninad Kulkarni

Masters Theses

“Selective laser melting is one of the commonly used additive manufacturing processes employed for production of functional part. Therefore, quality aspects such as dimensional accuracy have become a point of great interest. Like all of the other additive manufacturing processes selective laser melting process suffers from the issue if having wide range of process parameters making the process control a complex task. Additionally, issues specific to the selective laser melting process such as position dependency of accuracy of the part, makes it difficult to predict the resulting dimensional inconsistencies in the part manufactured by this processes. This research is an …

A Study Of The Potential Applications Of Am241, And Determining The Feasibility Of Using Gamma Spectroscopy For Future Physical Validation, Eric A. Feissle

Masters Theses

“Am241 is typically produced via Pu241 decay in a uranium fueled reactor. Presence of Am241 can be used as the age estimation tool for spent fuel, which is a focus of this thesis along with the interest of the measurement and the ratio of production rates of Am241’s activation products; Americium-242 and its first excited state of Americium-242m. MCNP models of the core and BEGe 3825 detector were built. These models were compared with established and physical measurements of gamma/x-ray standards that were available at the reactor. Thermal fluxes at 200 kW for potential foils centered in the source holder …

An Investigation Of Borax For Sealing Inflow From Berea Sandstone, Tri-Tris Bao Nguyen

Masters Theses

"Well inflow control is a major challenge for the oil and gas industry. Erle Haliburton revolutionized well inflow control with his patent for cementing oil wells in 1921. Soon after, cement became the accepted material to establish well integrity and has been ever since. Cement is used in all phases of the well life cycle, and it is expected to hold indefinitely once set. Yet based on the nature of cement and the placement techniques, flow pathways may develop from improper cementing jobs or from cement degradation over time. Well integrity is especially crucial for wellbore plugging and abandonment, since …

Dynamic Electromechanical Characterization Of Ferroelectrics At Cryogenic Temperatures, William Kent Hays

Masters Theses

"Electromechanical coupling in ferroelectric materials has given rise to a myriad of technological applications. Through the complex domain structure of ferroelectrics materials, which are typically stiff and have low damping, can exhibit significant structural damping. The applications for a material with a relatively large Young’s modulus and the ability to damp out vibrations would be useful for structures, more specifically, aerospace structures. The dynamic mechanical properties of ferroelectrics, particularly mechanical properties while an electric field is applied, are not well understood. This is due in part to the lack of experimental methods to measure such properties. Even with recent advancements …

Wrinkling Of Functionally Graded Sandwich Structures Subject To Biaxial And In-Plane Shear Loads, Harold Costa

Masters Theses

"Benefits of a functionally graded core increasing wrinkling stability of sandwich panels have been demonstrated in a recent paper [1] where a several-fold increase in the wrinkling stress was observed, without a significant weight penalty, using a stiffer core adjacent to the facings. In the present paper wrinkling is analyzed in case where the facings are subject to biaxial compression and/or in-plane shear loading and the core is arbitrary graded through-the-thickness. Two issues addressed are the effect of biaxial or in-plane shear loads on wrinkling stability of panels with both graded and ungraded core and the verification that functional grading …