Digital Commons Network^™

Semi-Empirical Modeling Of Liquid Carbon's Containerless Solidification, Philip C. Chrostoski

Doctoral Dissertations

“Elemental carbon has important structural diversity, ranging from nanotubes through graphite to diamond. Previous studies of micron-size core/rim carbon spheres extracted from primitive meteorites suggest they formed around such stars via the solidification of condensed carbon-vapor droplets, followed by gas-to-solid carbon coating to form the graphite rims. Similar core/rim particles result from the slow cooling of carbon vapor in the lab. The long-range carbon bond-order potential was used to computationally study liquid-like carbon in (1.8 g/cm³) periodic boundary (tiled-cube supercell) and containerless (isolated cluster) settings. Relaxations via conjugate-gradient and simulated-annealing nucleation and growth simulations using molecular dynamics were …

Extracting Metallurgy Contaminants And Hydrocarbons Removing From Water And Industrial Wastewater Using Enhanced Emulsion Liquid Membrane With Nanoparticles And Ionic Liquid, Qusay Al-Obaidi

Doctoral Dissertations

It is an uphill battle to extract pollutants such as heavy metals, hydrocarbons, and radioactive metals from water and industrial wastewater. Emulsion liquid membrane (ELM) is an emerging technology that combines extraction/recover and stripping in one stage to extract/recover heavy metals and/or hydrocarbons from water and wastewater. ELM devised a way to clean up heavy metals and/or hydrocarbons from the water and wastewater where its primary chemicals can be recycled and reused.

In this work, the Emulsion Liquid Membrane (ELM) has been enhanced by adding nanoparticles and ionic liquid to significantly improve the recovery of the water-based contaminants of heavy …

Dynamic Behavior And Interactions Of Ferrofluid Droplets Under Magnetic Fields In Low Reynolds Number Flows, Md Rifat Hassan

Doctoral Dissertations

Digital microfluidics in combination with emulsion microfluidics are crucial building blocks of droplet-based microfluidics, which are prevalent in a wide variety of industrial and biomedical applications, including polymer processing, food production, drug delivery, inkjet printing, and cell-based assays. Therefore, understanding the dynamics and interactions of droplets as well as the interactions between the droplets and solid surfaces are of great importance in order to improve the performance or product in these applications.

Recently, several studies in the literature have demonstrated the potential of magnetic fields in controlling the behavior of droplets in microscale; however, the fundamental mechanism behind the interesting …

Security Against Data Falsification Attacks In Smart City Applications, Venkata Praveen Kumar Madhavarapu

Doctoral Dissertations

Smart city applications like smart grid, smart transportation, healthcare deal with very important data collected from IoT devices. False reporting of data consumption from device failures or by organized adversaries may have drastic consequences on the quality of operations. To deal with this, we propose a coarse grained and a fine grained anomaly based security event detection technique that uses indicators such as deviation and directional change in the time series of the proposed anomaly detection metrics to detect different attacks. We also built a trust scoring metric to filter out the malicious devices. Another challenging problem is injection of …

Robustness Against Attacks And Uncertainties In Smart Cyber-Physical Systems, Prithwiraj Roy

Doctoral Dissertations

Cyber-Physical Systems (CPS) are sensing, processing, and communicating platforms, embedded with physical devices that provide real-time monitoring and control. Security challenges in CPS necessitate solutions that are robust against attacks and uncertainties and provide a seamless operation, especially when used in real-time applications to monitor and secure critical infrastructures. CPS mainly consists of a physical component for sensing or monitoring and a cyber component for processing and communicating. The quality of interactions between physical and cyber systems has direct impacts on the system’s performance and reliability.

CPS plays a major role in smart services and applications within a smart living …

Secure Data Sharing In Cloud And Iot By Leveraging Attribute-Based Encryption And Blockchain, Md Azharul Islam

Doctoral Dissertations

“Data sharing is very important to enable different types of cloud and IoT-based services. For example, organizations migrate their data to the cloud and share it with employees and customers in order to enjoy better fault-tolerance, high-availability, and scalability offered by the cloud. Wearable devices such as smart watch share user’s activity, location, and health data (e.g., heart rate, ECG) with the service provider for smart analytic. However, data can be sensitive, and the cloud and IoT service providers cannot be fully trusted with maintaining the security, privacy, and confidentiality of the data. Hence, new schemes and protocols are required …

Experimental And Numerical Studies Of Novel Thermal Energy Storage Materials For Applications In Concrete And Energy Storage Systems, Wenyu Liao

Doctoral Dissertations

In this work, several types of novel thermal energy storage (TES) materials and composites are explored, and a series of numerical simulation models and experimental protocols are developed to evaluate the potentials of these materials to be applied in concrete, pavement, and thermal energy storage systems.

The first two types of novel TES materials/composites are at the micro-scale, which use micro diatomite (DE) and cenosphere (Ceno) as carriers of phase change material (PCM), respectively. The third type of novel TES material is at the macro-scale, utilizing lightweight sand (LWS) and lightweight coarse aggregate as carriers to load PCM. The last …

Critical Behavior In Evolutionary And Population Dynamics, Stephen Walter Ordway

Doctoral Dissertations

“This study is an exploration of phase transition behavior in evolutionary and population dynamics, and techniques for predicting population changes, across the disciplines of physics, biology, and computer science. Under the looming threat of climate change, it is imperative to understand the dynamics of populations under environmental stress and to identify early warning signals of population decline. These issues are explored here in (1) a computational model of evolutionary dynamics, (2) an experimental system of decaying populations under environmental stress, and (3) a machine learning approach to predict population changes based on environmental factors. Through the lens of critical phase …

2020 Scholarly Productivity Report, Missouri University Of Science And Technology

Civil, Architectural and Environmental Engineering Scholarly Productivity Reports

No abstract provided.

Scholars' Mine Quick Facts December 2020, 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.

A Time Series Sustainability Assessment Of A Partial Energy Portfolio Transition, Jacob Hale, Suzanna Long

Engineering Management and Systems Engineering Faculty Research & Creative Works

Energy portfolios are overwhelmingly dependent on fossil fuel resources that perpetuate the consequences associated with climate change. Therefore, it is imperative to transition to more renewable alternatives to limit further harm to the environment. This study presents a univariate time series prediction model that evaluates sustainability outcomes of partial energy transitions. Future electricity generation at the state-level is predicted using exponential smoothing and autoregressive integrated moving average (ARIMA). The best prediction results are then used as an input for a sustainability assessment of a proposed transition by calculating carbon, water, land, and cost footprints. Missouri, USA was selected as a …

Local Electronic And Magnetic Properties Of The Doped Topological Insulators Bi₂Se₃:Ca And Bi₂Te₃:Mn Investigated Using Ion-Implanted ⁸Li Β-Nmr, Ryan M. L. Mcfadden, Aris Chatzichristos, David L. Cortie, Derek Fujimoto, Yew San Hor, Huiwen Ji, Victoria L. Karner, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We report β-NMR measurements in Bi₂Se₃:Ca and Bi₂Te₃:Mn single crystals using ⁸Li⁺ implanted to depths on the order of 100 nm. Above ∼200K, spin-lattice relaxation reveals diffusion of ⁸Li⁺, with activation energies of ∼0.4eV (∼0.2eV) in Bi₂Se₃:Ca (Bi₂Te₃:Mn). At lower temperatures, the NMR properties are those of a heavily doped semiconductor in the metallic limit, with Korringa relaxation and a small, negative, temperature-dependent Knight shift in Bi₂Se₃:Ca. From this, we make a detailed comparison with …

Inhibition Of Oxidative Metabolism By Nitric Oxide Restricts Emcv Replication Selectively In Pancreatic Beta-Cells, Joshua D. Stafford, Chay Teng Yeo, John A. Corbett

Biological Sciences Faculty Research & Creative Works

Environmental factors, such as viral infection, are proposed to play a role in the initiation of autoimmune diabetes. In response to encephalomyocarditis virus (EMCV) infection, resident islet macrophages release the pro-inflammatory cytokine IL-1b, to levels that are sufficient to stimulate inducible nitric oxide synthase (iNOS) expression and production of micromolar levels of the free radical nitric oxide in neighboring b-cells. We have recently shown that nitric oxide inhibits EMCV replication and EMCV-mediated b-cell lysis and that this protection is associated with an inhibition of mitochondrial oxidative metabolism. Here we show that the protective actions of nitric oxide against EMCV infection …

Significance Of Reagents Addition Sequence On Iron Anionic Reverse Flotation And Their Adsorption Characteristics Using Qcm-D, Ying Hou, Ahmed Sobhy, Yue Wang

Mining Engineering Faculty Research & Creative Works

To explore the influence of reagents addition sequence of the pH regulator and the starch depressant on the anionic reverse flotation of iron oxide, flotation conditional experiments were performed on mixed low-intensity and high-gradient magnetic concentrates which is the flotation feed acquired from the iron processing plant. Besides, quartz crystal micro-balance with dissipative (QCMD) was conducted to detect the adsorption phenomena of the flotation reagent on iron oxide sensors at different addition orders. The outcomes showed that the flotation performance using the pH regulator prior to the depressant was the best. For example, at 1.6 kg/Mg starch dosage, the recovery …

Effect Of Temperature On Early‐Age Properties Of Self‐Consolidating Concrete Equivalent Mortar, Nima Farzadnia, Jing Pan, Kamal Khayat, Eric Wirquin

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, the effect of ambient temperature during casting on fresh properties, hydration kinetics, and early‐age compressive strength of self-consolidating concrete (SCC) was evaluated. Concrete equivalent mortars (CEMs) with water‐to‐binder ratios of 0.41 and 0.45 were cast based on SCC mixture designs for building and infrastructure construction and precast applications. The CEMs were prepared at temperatures ranging from 8 to 36°C. Superplasticizer (SP) and air‐entraining agent (AEA) demand were evaluated for the CEM mixtures made with different supplementary cementing material (SCM) and limestone filler types. Test results showed that the ambient temperature can significantly affect the SP and AEA …

Cf⁺ Excitation In The Interstellar Medium, Benjamin Desrousseaux, François Lique, Javier R. Goicoechea, Ernesto Quintas-Sánchez, Richard Dawes

Chemistry Faculty Research & Creative Works

The detection of CF⁺ in interstellar clouds potentially allows astronomers to infer the elemental fluorine abundance and the ionization fraction in ultraviolet-illuminated molecular gas. Because local thermodynamic equilibrium (LTE) conditions are hardly fulfilled in the interstellar medium (ISM), the accurate determination of the CF⁺ abundance requires one to model its non-LTE excitation via both radiative and collisional processes. Here, we report quantum calculations of rate coefficients for the rotational excitation of CF⁺ in collisions with para- and ortho-H₂ (for temperatures up to 150 K). As an application, we present non-LTE excitation models that reveal population inversion …

Triple-Differential Cross Sections For (E,2e) Electron-Impact Ionization Dynamics Of Tetrahydrofuran At Low Projectile Energy, Enliang Wang, Xueguang Ren, Maomao Gong, Esam Ali, Zhenpeng Wang, Chao Ma, Don H. Madison, Xiangjun Chen, Alexander Dorn

Physics Faculty Research & Creative Works

We study the triple-differential cross section (TDCS) for the electron-impact ionization of the highest occupied molecular orbital of tetrahydrofuran at a projectile energy E0=91eV. The experimental data were measured using a reaction microscope, which covers a large part of the full solid angle for the secondary electron emission with energies ranging from 6 to 15 eV, and projectile scattering angles ranging from -10° to -20°. The experimental TDCSs are internormalized across all measured scattering angles and ejected energies. They are compared with predictions from the multicenter distorted-wave (MCDW) approximation and a modified MCDW-Nee method which includes the post collision interaction …

Inter-Cross De-Modulated Refractive Index And Temperature Sensor By An Etched Multi-Core Fiber Of A Mzi Structure, Farhan Mumtaz, Yutang Dai, Muhammad Aqueel Ashraf

Electrical and Computer Engineering Faculty Research & Creative Works

We present a relative sensitivity of in-fiber inter-cross demodulation of a Mach-Zehnder interferometer (MZI) based on an etched multi-core fiber (eMCF). The sensor can measure the external refractive index (RI) and temperature with a large fringe visibility of 15 dB. It is tuned using a simple technique of slow chemical etching. When the outer cores of MCF will be exposed to the surrounding, a large difference of relative effective RI is observed, which enhances the sensitivity of the sensor. The sensor's wavelength and intensity responses have displayed that it can function with three different inter-cross-demodulation phenomena. A superior RI sensitivity …

Finding All ∈-Good Arms In Stochastic Bandits, Blake Mason, Lalit Jain, Ardhendu S. Tripathy, Robert Nowak

Computer Science Faculty Research & Creative Works

The pure-exploration problem in stochastic multi-armed bandits aims to find one or more arms with the largest (or near largest) means. Examples include finding an ∈-good arm, best-arm identification, top-k arm identification, and finding all arms with means above a specified threshold. However, the problem of finding all ∈-good arms has been overlooked in past work, although arguably this may be the most natural objective in many applications. For example, a virologist may conduct preliminary laboratory experiments on a large candidate set of treatments and move all ∈-good treatments into more expensive clinical trials. Since the ultimate clinical efficacy is …

Distributed De Novo Assembler For Large-Scale Long-Read Datasets, Sayan Goswami, Kisung Lee, Seung Jong Park

Computer Science Faculty Research & Creative Works

Third-generation DNA sequencing technologies such as single-molecule real-time sequencing (SMRT) and nanopore sequencing have the potential to fill the gaps in the existing genome databases since the raw sequences produced by these machines are much longer than those of previous generations and therefore result in more contiguous assemblies. However, these long reads have a high error rate, which makes the assembly process computationally challenging. Moreover, since existing long-read assemblers are designed to run on a single machine, they either take days to complete or run out of memory on even moderate-sized datasets. In this paper, we present a distributed long-read …

The Missouri Miner, December 9, 2020

The Missouri Miner Newspaper

No abstract provided.

Welcome Message From The Tpc Chairs, Ming Yu, Lijun Jiang, Alex Man Hon Wong, Shao Yong Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Applying Power Dividers To Decoupling Of Mimo Antennas With Wideband, Dual-Band Or Adjacent-Band Operations, Min Li, Lijun Jiang, Kwan Lawrence Yeung

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel decoupling method of applying power dividers to isolation enhancement of multiple-input multiple-output antennas with wideband, dual-band, or adjacent-band operations. The decoupling structure consists of the power dividers, transmission lines, and reactive components. Three benchmarks are used to elaborate on the design procedure and demonstrate the advantages of the proposed method. Results show that this method offers good impedance matching and high port isolation at the designated frequencies.

Structural Determinants Of Flavin Dynamics In A Class B Monooxygenase, Ashley C. Campbell, Reeder Robinson, Didier Mena-Aguilar, Pablo Sobrado, John J. Tanner

Chemistry Faculty Research & Creative Works

The ornithine hydroxylase known as SidA is a class B flavin monooxygenase that catalyzes the first step in the biosynthesis of hydroxamate-containing siderophores in Aspergillus fumigatus. Crystallographic studies of SidA revealed that the FAD undergoes dramatic conformational changes between out and in states during the catalytic cycle. We sought insight into the origins and purpose of flavin motion in class B monooxygenases by probing the function of Met101, a residue that contacts the pyrimidine ring of the in FAD. Steady-state kinetic measurements showed that the mutant variant M101A has a 25-fold lower turnover number. Pre-steady-state kinetic measurements, pH profiles, and …

Kron-Branin Model Of Braided Coaxial Cable Illuminated By Electromagnetic Wave, Ping Wu, Cui Meng, Zhifei Xu, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper develops an innovative model of shielded coaxial cable illuminated by high power electromagnetic pulse. This Kron-Branin model is a flexible and efficient way of wave-circuit hybrid calculation, which is based on Branin's transmission line (TL) model and tensorial analysis of network (TAN). The traditional equivalent circuit is transferred into a topology graph consists of basic elements like nodes, branches, meshes, and cords. Electromagnetic and circuit equations can be derived and transferred according to the graph. The graph topology and equivalent transmission line equation of illuminated shielded cable structure is presented in this paper. A good correlation between the …

Ccfss Technical Bulletin Fall 2020, Vol. 21, Number 3, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.

Scholars' Mine Quick Facts November 2020, 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.

Ccfss Technical Bulletin Fall 2020, Vol. 21, Number 2, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.

Scholars' Mine Quick Facts October 2020, 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.

The Missouri Miner, December 2, 2020

The Missouri Miner Newspaper

No abstract provided.