Digital Commons Network^™

Design Of Lattice Structures With Graded Density Fabricated By Additive Manufacturing, Wenjin Tao, Yong Liu, Austin T. Sutton, Krishna C. R. Kolan, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Lattice structures fabricated by Additive Manufacturing (AM) processes are promising for many applications, such as lightweight structures and energy absorbers. However, predicting and controlling of their mechanical behaviors is challenging due to the complexity of modeling and the uncertainties exist in the manufacturing process. In this paper, we explore the possibilities enabled by controlling the local densities. A set of lattice structures with different density gradients are designed using an implicit isosurface equation, and they are manufactured by Selective Laser Melting (SLM) process with 304L stainless steel. Finite element analysis and compression test are used to evaluate their mechanical properties. …

Seismic Performance And Retrofit Evaluation Of Hollow-Core Composite Bridge Columns, Mohanad M. Abdulazeez, Ahmed Gheni, Nicholas Colbert, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the seismic behavior of large-scale hollow-core fiber-reinforced polymerconcrete-steel (HC-FCS) bridge column. The HC-FCS column consists of a concrete wall sandwiched between an outer fiber-reinforced polymer (FRP) tube and an inner thin-walled steel tube. The width-to-diameter ratio for the steel tube was 147. The column had an outer diameter of 24 inches and a height-to-diameter ratio of 4.0. The steel tube was embedded into reinforced concrete footing with an embedded length of 1.25 times the steel tube diameter, while the FRP tube only confined the concrete wall thickness and curtail at the top of the footing level. The …

Correction: Orbital Angular Momentum Generation And Detection By Geometric-Phase Based Metasurfaces [Appl. Sci., 8, (2018), (362)] Doi:10.3390/App8030362, Menglin L.N. Chen, Li (Lijun) Jun Jiang, Wei E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

We, the authors, wish to make the following corrections to our paper [1]. We found that the literature we listed on page 2 has a mistake: "Afterwards, many other devices for OAM generation have been proposed, such as the cylindrical lens in 1993 [30], spiral phase plates (SPPs) in 1994 [31], q plates in 2006 [32]." We would like to give credit to the first phase rotor filter [2] and remove the year for the designs. Thus, the statement would be changed to: "In 1992, a phase rotor filter was devised to introduce the azimuthal phase term [30]. Afterwards, many …

Cafe Introduces New Rolling Acceptance For Proposals, Missouri University Of Science And Technology

CAFE Announcements

No abstract provided.

Certi Merges Into Cafe, Provides Faculty One Stop For Professional Development, Missouri University Of Science And Technology

CAFE Announcements

No abstract provided.

Analysis Of Grapevine Gene Expression Data Using Node-Based Resilience Clustering, Jeffrey Dale, John Matta, Susanne Howard, Gunes Ercal, Wenping Qiu, Tayo Obafemi-Ajayi

Electrical and Computer Engineering Faculty Research & Creative Works

Powdery mildew is the most economically important disease of cultivated grapevines worldwide. In the agricultural community, there is a great need for better understanding of the complex genetic basis of powdery mildew (PM) resistance by delineating possible gene biomarkers associated with the plants' defense mechanisms. Machine learning techniques can be applied to analysis of gene expression data to aid knowledge discovery of disease fighting genes. In this work, we apply a data-driven computational model, utilizing a graph-based clustering algorithm - Node-Based Resilience Clustering (NBRClust), to analyze grapevine gene expression data to identify possible gene biomarkers associated with powdery mildew disease …

A Unified Analysis Framework For Tensor Metasurfaces, Bo O. Zhu, Xiaoyan Y.Z. Xiong, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Tensor impedance metasurfaces have attracted much attention recently due to their ability to flexibly manipulate both propagating and surface waves. So far, the analysis of tensor impedance has not been fully supported by commercial electromagnetic simulation software. Also, the representation of formulas of penetrable tensor impedance for both propagating and surface waves is limited in the literature. Hence, a unified analysis framework is proposed for this purpose. It allows the calculation of wave reflection and transmission with arbitrary incident angles, or inversely, the calculation of surface impedance tensors given the desired wave propagation properties. It also allows surface eigenmode analysis, …

Steric Control Of The Rate-Limiting Step Of Udp-Galactopyranose Mutase, Gustavo Pierdominici-Sottile, Rodrigo Cossio-Pérez, Isabel Da Fonseca, Karina Kizjakina, John J. Tanner, Pablo Sobrado

Chemistry Faculty Research & Creative Works

Galactose is an abundant monosaccharide found exclusively in mammals as galactopyranose (Galp), the six-membered ring form of this sugar. In contrast, galactose appears in many pathogenic microorganisms as the five-membered ring form, galactofuranose (Galf). Galf biosynthesis begins with the conversion of UDP-Galp to UDP-Galf catalyzed by the flavoenzyme UDP-galactopyranose mutase (UGM). Because UGM is essential for the survival and proliferation of several pathogens, there is interest in understanding the catalytic mechanism to aid inhibitor development. Herein, we have used kinetic measurements and molecular dynamics simulations to explore the features of UGM that control the rate-limiting step (RLS). We show that …

The Caching Broadcast Channel With A Wire And Cache Tapping Adversary Of Type Ii, Mohamed Nafea, Aylin Yener

Electrical and Computer Engineering Faculty Research & Creative Works

This paper introduces the notion of cache-tapping into information theoretic models of coded caching. In particular, the wiretap II model with two receivers equipped with fixed-size cache memories is considered. The adversary chooses a set of symbols from cache placement, delivery, or both to tap into. The legitimate parties know neither whether cache placement, delivery, or both transmissions are tapped, nor the positions of tapped symbols. Only the size of overall tapped set is known. The strong secrecy capacity, i.e., the maximum achievable file rate while keeping the overall library strongly secure, is identified for the instance of two library …

The Caching Broadcast Channel With A Wire And Cache Tapping Adversary Of Type Ii: Multiple Library Files, Mohamed Nafea, Aylin Yener

Electrical and Computer Engineering Faculty Research & Creative Works

A wiretap model with two receivers equipped with fixed-size cache memories, and a type II adversary is considered. The adversary in this model chooses a subset of symbols to tap into either from cache placement, delivery transmission, or both phases. The legitimate parties do not know the fractions or the positions of the tapped symbols in either phase. For a library of size three files or more, lower and upper bounds on the strong secrecy capacity, i.e., the maximum achievable file rate while keeping the overall library strongly secure, are derived. The strong secrecy capacity is identified for the instance …

Effects Of Flight Activity And Age On Oxidative Damage In The Honey Bee, Apis Mellifera, Joseph W. Margotta, Stephen P. Roberts, Michelle M. Elekonich

Biological Sciences Faculty Research & Creative Works

Frequent and Highly Aerobic Behaviors Likely Contribute to Naturally Occurring Stress, Accelerate Senescence and Limit Lifespan. to Understand How the Physiological and Cellular Mechanisms that Determine the Onset and Duration of Senescence Are Shaped by Behavioral Development and Behavioral Duration, We Exploited the Tractability of the Honeybee (Apis Mellifera) Model System. First, We Determined Whether a Cause-Effect Relationship Exists between Honeybee Flight and Oxidative Stress by Comparing Oxidative Damage Accrued from Intense Flight Bouts to Damage Accrued from D-Galactose Ingestion, Which Induces Oxidative Stress and Limits Lifespan in Other Insects. Second, We Experimentally Manipulated the Duration of Honeybee Flight Across …

Scholars' Mine Annual Report For Fiscal Year Ending June 2018, James Roger Weaver

Scholars’ Mine Statistics

Scholars' Mine annual statistics report for the fiscal year ending June 2018.

Scholars' Mine Quick Facts July 2018, Nancy S. Krost

Scholars’ Mine Statistics

Scholars' Mine Quick Facts are monthly reports of downloads, page hits, and other information about works in the institutional repository of Missouri S&T. A map with downloads by region is also included.

Interrogating The Central Melanocortin System: Choosing The “Right” Model, Gina L.C. Yosten

Biological Sciences Faculty Research & Creative Works

No abstract provided.

The Automated Design Of Probabilistic Selection Methods For Evolutionary Algorithms, Samuel N. Richter, Daniel R. Tauritz

Computer Science Faculty Research & Creative Works

Selection functions enable Evolutionary Algorithms (EAs) to apply selection pressure to a population of individuals, by regulating the probability that an individual's genes survive, typically based on fitness. Various conventional fitness based selection methods exist, each providing a unique relationship between the fitnesses of individuals in a population and their chances of selection. However, the full space of selection algorithms is only limited by max algorithm size, and each possible selection algorithm is optimal for some EA configuration applied to a particular problem class. Therefore, improved performance may be expected by tuning an EA's selection algorithm to the problem at …

Evolution Of Network Enumeration Strategies In Emulated Computer Networks, Sean Harris, Eric Michalak, Kevin Schoonover, Adam Gausmann, Hannah Reinbolt, Joshua Herman, Daniel R. Tauritz, Chris Rawlings, Aaron Scott Pope

Computer Science Faculty Research & Creative Works

Successful attacks on computer networks today do not often owe their victory to directly overcoming strong security measures set up by the defender. Rather, most attacks succeed because the number of possible vulnerabilities are too large for humans to fully protect without making a mistake. Regardless of the security elsewhere, a skilled attacker can exploit a single vulnerability in a defensive system and negate the benefits of those security measures. This paper presents an evolutionary framework for evolving attacker agents in a real, emulated network environment using genetic programming, as a foundation for coevolutionary systems which can automatically discover and …

Automated Design Of Network Security Metrics, Aaron Scott Pope, Daniel R. Tauritz, Robert Morning, Alexander D. Kent

Computer Science Faculty Research & Creative Works

Many abstract security measurements are based on characteristics of a graph that represents the network. These are typically simple and quick to compute but are often of little practical use in making real-world predictions. Practical network security is often measured using simulation or real-world exercises. These approaches better represent realistic outcomes but can be costly and time-consuming. This work aims to combine the strengths of these two approaches, developing efficient heuristics that accurately predict attack success. Hyper-heuristic machine learning techniques, trained on network attack simulation training data, are used to produce novel graph-based security metrics. These low-cost metrics serve as …

Identification Of Transportation Infrastructure At Risk Due To Sea Level Rise And Subsidence Of Land In Coastal Louisiana, Sanjay Tewari, Wesley Palmer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The coast of Louisiana is under threat because of sea level rise and land subsidence. Sea water is encroaching deeper inland and as a result Louisiana is losing at an alarming rate. The combined effect of sea level rise and land subsidence is variable spatially. This paper focuses on this combined effect in identifying the transportation infrastructure that is at risk of getting affected by the sea-water inundation of the land.

This paper is an attempt of taking account of land elevation data monitored continuously at various locations along the coast of Louisiana and combining it with local sea level …

A Network Tomography Approach For Traffic Monitoring In Smart Cities, Ruoxi Zhang, Sara Newman, Marco Ortolani, Simone Silvestri

Computer Science Faculty Research & Creative Works

Traffic monitoring is a key enabler for several planning and management activities of a Smart City. However, traditional techniques are often not cost efficient, flexible, and scalable. This paper proposes an approach to traffic monitoring that does not rely on probe vehicles, nor requires vehicle localization through GPS. Conversely, it exploits just a limited number of cameras placed at road intersections to measure car end-to-end traveling times. We model the problem within the theoretical framework of network tomography, in order to infer the traveling times of all individual road segments in the road network. We specifically deal with the potential …

Multi-Objective Optimization Based Allocation Of Heterogeneous Spatial Crowdsourcing Tasks, Liang Wang, Zhiwen Yu, Qi Han, Bin Guo, Haoyi Xiong

Computer Science Faculty Research & Creative Works

With the rapid development of mobile networks and the proliferation of mobile devices, spatial crowdsourcing, which refers to recruiting mobile workers to perform location-based tasks, has gained emerging interest from both research communities and industries. In this paper, we consider a spatial crowdsourcing scenario: in addition to specific spatial constraints, each task has a valid duration, operation complexity, budget limitation, and the number of required workers. Each volunteer worker completes assigned tasks while conducting his/her routine tasks. The system has a desired task probability coverage and budget constraint. Under this scenario, we investigate an important problem, namely heterogeneous spatial crowdsourcing …

Holmium And Samarium Detectability In Post-Blast Residue, James Seman, Catherine E. Johnson, Carlos Henry Castano Giraldo

Mining Engineering Faculty Research & Creative Works

The creation of an identification taggant that survives detonation and can easily be recovered would prove invaluable in situations such as a terrorist attack where the explosives have been detonated and need to be traced by law enforcement. This paper shows that traces of two elements, samarium (Sm) and holmium (Ho), can be identified from explosive post-blast residue. This is the first step to creating a viable taggant system that survives detonation. The two elements were introduced to the explosive before detonation, and the post-blast residue was analyzed by neutron activation analysis (NAA). These data indicate the presence of these …

Microwave-Assisted Synthesis Of Palladium Nanoparticles Supported On Copper Oxide In Aqueous Medium As An Efficient Catalyst For Suzuki Cross-Coupling Reaction, Hany A. Elazab, M. A. Sadek, Tamer T. El-Idreesy

Chemical and Biochemical Engineering Faculty Research & Creative Works

We report here a reliable green method for the synthesis of palladium nanoparticles supported on copper oxide as a highly active and efficient catalyst for Suzuki cross-coupling reaction. The experimental synthetic approach is based on microwave-assisted chemical reduction of an aqueous mixture of palladium and copper salt simultaneously using hydrazine hydrate as reducing agent. The catalyst was fully characterized using various techniques showing well-dispersed palladium nanoparticles. The catalytic activity and recyclability of the prepared catalyst were experimentally explored in the ligand-free Suzuki cross-coupling reaction with a diverse series of functionalized substrates. The synthesized Pd/CuO catalyst shows many advantages beside its …

A Nonlinear Crack Model For Concrete Structure Based On An Extended Scaled Boundary Finite Element Method, Jian-Bo Li, Xin Gao, Xing-An Fu, Chenglin Wu, Gao Lin

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Fracture mechanics is one of the most important approaches to structural safety analysis. Modeling the fracture process zone (FPZ) is critical to understand the nonlinear cracking behavior of heterogeneous quasi-brittle materials such as concrete. In this work, a nonlinear extended scaled boundary finite element method (X-SBFEM) was developed incorporating the cohesive fracture behavior of concrete. This newly developed model consists of an iterative procedure to accurately model the traction distribution within the FPZ accounting for the cohesive interactions between crack surfaces. Numerical validations were conducted on both of the concrete beam and dam structures with various loading conditions. The results …

Detonation Synthesis Of Alpha-Variant Silicon Carbide, Martin Langenderfer, Catherine E. Johnson, William Fahrenholtz, Vadym Mochalin

Mining Engineering Faculty Research & Creative Works

A recent research study has been undertaken to develop facilities for conducting detonation synthesis of nanomaterials. This process involves a familiar technique that has been utilized for the industrial synthesis of nanodiamonds. Developments through this study have allowed for experimentation with the concept of modifying explosive compositions to induce synthesis of new nanomaterials. Initial experimentation has been conducted with the end goal being synthesis of alpha variant silicon carbide (α-SiC) in the nano-scale. The α-SiC that can be produced through detonation synthesis methods is critical to the ceramics industry because of a number of unique properties of the material. Conventional …

Repeated Loading Model For Elastic-Plastic Contact Of Geomaterial, Jian Wang, Qimin Li, Changwei Yang, Caizhi Zhou

Materials Science and Engineering Faculty Research & Creative Works

A new nonlinear hysteretic model with considering the loading, unloading, and reloading processes is developed based on Drucker—Prager yield criterion and finite-element analysis. This model can be used for multiple repeated elastic—plastic normal direction contact problems between two identical spherical geomaterials. After examining the influence of material properties, strain hardening, and loading histories, we found that the hysteretic phenomena (represented by residual displacement and plastic work) become weak after the first cycle, and the subsequent cycles step into elastic shakedown state eventually. A critical number of cycles can be used to estimate the state of ratchetting, plastic shakedown, as well …

Enhancing Manual P-Phase Arrival Detection And Automatic Onset Time Picking In A Noisy Microseismic Data In Underground Mines, Charles Mborah, Maochen Ge

Mining Engineering Faculty Research & Creative Works

Accurate detection and picking of the P-phase onset time in noisy micro seismic data from underground mines remains a big challenge. Reliable P-phase onset time picking is necessary for accurate source location needed for planning and rescue operations in the event of failures. In this paper, a new technique based on the discrete stationary wavelet transform (DSWT) and higher order statistics is proposed for processing noisy data from underground mines. The objectives of this method are to (i) improve manual detection and picking of P-phase onset; and (ii) provide an automatic means of detecting and picking P-phase onset time accurately. …

Tuning A Random-Field Mechanism In A Frustrated Magnet, Shashikant Singh Kunwar, Arnab Sen, Thomas Vojta, Rajesh Narayanan

Physics Faculty Research & Creative Works

We study the influence of spinless impurities on a frustrated magnet featuring a spin-density wave (stripe) phase by means of Monte Carlo simulations. We demonstrate that the interplay between the impurities and an order parameter that breaks a real-space symmetry triggers the emergence of a random-field mechanism which destroys the stripe-ordered phase. Importantly, the strength of the emerging random fields can be tuned by the repulsion between the impurity atoms; they vanish for perfect anticorrelations between neighboring impurities. This provides a way of controlling the phase diagram of a many-particle system. In addition, we also investigate the effects of the …

Software For Peak Finding And Elemental Composition Assignment For Glycosaminoglycan Tandem Mass Spectra, John D. Hogan, Joshua A. Klein, Jiandong Wu, Pradeep Chopra, Geert Jan Boons, Luis Carvalho, Cheng Lin, Joseph Zaia

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glycosaminoglycans (GAGs) Covalently Linked to Proteoglycans (PGs) Are Characterized by Repeating Disaccharide Units and Variable Sulfation Patterns Along the Chain. GAG Length and Sulfation Patterns Impact Disease Etiology, Cellular Signaling, and Structural Support for Cells. We and Others Have Demonstrated the Usefulness of Tandem Mass Spectrometry (MS 2 ) for Assigning the Structures of GAG Saccharides; However, Manual Interpretation of Tandem Mass Spectra is Time-Consuming, So Computational Methods Must Be Employed. in the Proteomics Domain, the Identification of Monoisotopic Peaks and Charge States Relies on Algorithms that Use Averagine, or the Average Building Block of the Compound Class Being Analyzed. …

Significant Improvement In Tio₂ Photocatalytic Activity Through Controllable Zro₂ Deposition, Xiaofeng Wang, Rajankumar L. Patel, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

ZrO₂ was deposited on anatase TiO₂ nanoparticles using 5-80 cycles of atomic layer deposition (ALD). The photocatalytic activity of all samples was evaluated based on the degradation of methylene blue (MB) solution under UV light. The TiO₂ sample with 45 cycles of ZrO₂ deposition (45c-Zr/TiO₂, 1.1 wt% ZrO₂) was proved to be the most efficient catalyst with a degradation kinetic constant 10 times larger than that of the pure TiO₂ sample. All samples were characterized using inductively coupled plasma atomic emission spectroscopy (ICP-AES), nitrogen adsorption-desorption, X-ray diffraction (XRD), transmission electron microscopy …

Discontinuous Galerkin Time-Domain Modeling Of Graphene Nanoribbon Incorporating The Spatial Dispersion Effects, Ping Li, Li (Lijun) Jun Jiang, Hakan Bagci

Electrical and Computer Engineering Faculty Research & Creative Works

It is well known that graphene demonstrates spatial dispersion properties, i.e., its conductivity is nonlocal and a function of spectral wavenumber (momentum operator) q. In this paper, to account for effects of spatial dispersion on transmission of high-speed signals along graphene nanoribbon (GNR) interconnects, a discontinuous Galerkin time-domain (DGTD) algorithm is proposed. The atomically thick GNR is modeled using a nonlocal transparent surface impedance boundary condition (SIBC) incorporated into the DGTD scheme. Since the conductivity is a complicated function of q (and one cannot find an analytical Fourier transform pair between q and spatial differential operators), an exact time-domain SIBC …