Digital Commons Network^™

Relating Detonation Parameters To The Detonation Synthesis Of Nanomaterials, Martin Langenderfer

Doctoral Dissertations

“This research investigates the physical and chemical processes that contribute to the detonation synthesis of silicon carbide nanoparticles. Bulk production of SiC nanoparticles through detonation is possible due to pressures achieved over 20 GPa and temperatures over 2000 K as well as quenching rates in excess of 13 billion K/second. These conditions catalyze reaction and bottom-up molecular growth while retaining particles < 100 nm in diameter. In this work, detonation synthesis of SiC was demonstrated by incorporation of polycarbosilane, an SiC precursor material, into an RDX/TNT explosive matrix prior to detonation. Detonation Synthesis of SiC was also accomplished by reacting elemental silicon with carbon liberated by the detonation of negatively oxygen balanced TNT. Hydrodynamic simulation of a 60:40 mass ratio RDX/TNT detonation created conditions thermodynamically suitable to produce cubic silicon carbide within the first 500 nanoseconds after the passage of the detonation wave while carbon remains chemically reactive for molecular formation. Simulations and experimental tests indicated that loading configuration and impedance mismatch of the precursor additives used in detonation synthesis results in conditions in the additives that exceed the accepted detonation pressure of the explosive by greater than three times. Finally, a full factorial experimental design showed increasing silicon concentration, reducing silicon size, and reducing oxygen balance by adjusting the ratio of RDX to TNT decreased the explosives detonation pressure by 20% and increased the soot yield and concentration of SiC observed in the detonation products by 82% and 442% respectively”--Abstract, page iv.

Investigation Of Anomalous Data Trends During Coal Dust Explosibilty Testing, Jacob Lee Miller

Doctoral Dissertations

Coal dust explosibility is a health and safety concern that has been a recognized hazard for over 100 years. Initial testing by the Author using a Siwek 20L apparatus recorded a secondary maximum pressure at higher dust concentrations (1,000-7,000g/m³) with Pulverized Pittsburgh Coal (PCC). Higher dust concentrations are beyond the typical ASTM E1226 testing procedure but are possible in mining and processing scenarios. No reference documents have been discovered that show a secondary maximum pressure at higher dust concentrations. Literature reviewed identified that once a coal dust concertation generates a peak pressure, the pressure remains constant or decreases …

An Investigation Of Unsteady Thermal Exchange Processes In Geothermal Heat Exchangers, Ganesh Ravi Shanker

Doctoral Dissertations

“Geothermal heat exchangers, has become one of the highly recognized non conventional heat exchangers as they utilize renewable energy source earth to initiate the thermal energy transfer. However, these heat exchangers suffer from a expensive installation cost due to their conservative design model, thereby facilitating the need to identify and improve the design. In this dissertation, three gaps, which identifies improvement over conservative design were investigated, to assess the heat exchanger performance. In the first approach, borehole thermal and geometrical properties were investigated keeping the outlet leg of the heat exchanger as adiabatic, which neglects the thermal short-circuiting between the …

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 …

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 …

Development Of High-Performance Hydrogels, Buddhabhushan Salunkhe

Doctoral Dissertations

Here, we present a systematic approach to design robust hydrogel compositions. The goal was to achieve excellent properties to open up new opportunities in especially two challenging applications not previously well-served by hydrogels.

The first part of this research will discuss the systematic screening of polymers for their hydrothermal stability under brine, acidic, neutral, and basic pH conditions followed by novel designs of hydrogel compositions. Certain hydrogel compositions withstand temperatures of up to 150 °C for more than 24 months in high salinity brines. This novel hydrogel composition fills a technology gap between the existing polyacrylamide-based preformed particle gels (PPGs) …

Modeling For Off-Chip High-Speed Designs, Siqi Bai

Doctoral Dissertations

”Signal integrity (SI) and power integrity (PI) are essential for datacenter application. A typical datacenter rack consists of a switch on the top of the rack, servers, and storage units. Three SI/PI related problems for datacenter application are analyzed in this research.

The first topic is analysis on power via induced Quasi-quarter-wavelength resonance to reduce crosstalk. Using an analytical model and 3D full-wave simulation models, a physical explanation for the unexpected resonance in the differential signal pairs is proposed. Considering the difficulty in changing the pin map of the IC-package, several PCB layouts to eliminate the power via induced quasi-quarter-wavelength …

Data And Resource Management In Wireless Networks Via Data Compression, Gps-Free Dissemination, And Learning, Xiaofei Cao

Doctoral Dissertations

“This research proposes several innovative approaches to collect data efficiently from large scale WSNs. First, a Z-compression algorithm has been proposed which exploits the temporal locality of the multi-dimensional sensing data and adapts the Z-order encoding algorithm to map multi-dimensional data to a one-dimensional data stream. The extended version of Z-compression adapts itself to working in low power WSNs running under low power listening (LPL) mode, and comprehensively analyzes its performance compressing both real-world and synthetic datasets. Second, it proposed an efficient geospatial based data collection scheme for IoTs that reduces redundant rebroadcast of up to 95% by only collecting …

Adaptive Dynamic Programming Methods For Tracking Current Control Of Switched Reluctance Motor Drive, Hamad Alharkan

Doctoral Dissertations

“This research investigates the application of adaptive dynamic programming (ADP) methods for the current control of switched reluctance motors (SRM). Since the traditional current controllers have large current ripples that increase torque ripples and acoustic noise, optimal tracking controllers using reinforcement learning (RL) approaches are introduced as an alternative adaptive technique for SRM drives. The proposed optimal tracking controllers can minimize current ripples and cope with uncertainties within the inductance profile of the SRM. The work is composed of three papers. In the first paper, a novel Q-learning scheduling method for the current controller of a switched reluctance motor (SRM) …

Advanced Control Techniques For Modern Inertia Based Inverters, Sepehr Saadatman

Doctoral Dissertations

”In this research three artificial intelligent (AI)-based techniques are proposed to regulate the voltage and frequency of a grid-connected inverter. The increase in the penetration of renewable energy sources (RESs) into the power grid has led to the increase in the penetration of fast-responding inertia-less power converters. The increase in the penetration of these power electronics converters changes the nature of the conventional grid, in which the existing kinetic inertia in the rotating parts of the enormous generators plays a vital role. The concept of virtual inertia control scheme is proposed to make the behavior of grid connected inverters more …

Perception Of Stakeholders On Current Perfusion Education In Malaysia, Rafiq Sumardi Omar

Student Works (2020-2029)

Perfusionist is known as a certified medical technician liable for extracorporeal oxygenation of the blood during open-heart surgery. Current curriculum is believed to be at par and is aligned with the National Occupational Skills Standard, however, the scope of perfusion practice keeps changing with the advancement of technology and procedures, and there is a demand for specialty area such as extracorporeal membrane oxygenation (ECMO). Therefore, current curriculum should be re-evaluated by taking consideration from multiple stakeholders’ perception on current needs, content, educational strategies, teaching methods, assessment methods, and curriculum management. Hence, this study aimed to explore perception of stakeholders in …

Adaptation Of The Medical Ethics Teaching Questionnaire For The Use Of Taiwanese Medical Students: A Developmental Study, Lee Jing Ning

Student Works (2020-2029)

Medical ethics is among one of the most important competencies in medical education and formal physicians' training. In the past decades, medical ethics education has become a priority within medical education institutions worldwide. In Taiwan, medical ethics was included in the undergraduate medical curricula since 1995. However, students� view upon graduation revealed that they were still lacked confidence about beginning their residency program due to limited understanding of ethical values. Taiwan, as a country with unique cultural belief in the traditional Confucian principles that emphasizes the virtue of �filial piety� and family cohesion in medical decision-making is lacking Taiwanese studies …

Assessing Early Literacy Using School-Based Assessment, Nur Amalina Dayana Abd Aziz

Student Works (2020-2029)

Early literacy is an important foundation for learning. The importance of having mastered literacy early is not limited to students’ success at school but also extends into their after-school lives. Students with a good foundation in literacy are better prepared to participate as citizens. In line with the Ministry of Education Malaysia’s vision of producing world-class citizens, school-based assessment was first implemented in primary schools in 2011. Various studies on aspects such as teachers’ readiness, knowledge, understanding and practice of school-based assessment have been conducted using the quantitative method and within the context of secondary schools. The current study therefore …

Cannibalism, Oviposition And Egg Development In The Edible Long-Horned Grasshopper, Ruspolia Differens (Orthoptera: Tettigoniidae) Under Laboratory Conditions, J. P. Egonyu, M. M. Miti, C. M. Tanga, A. Leonard, S. Subramanian

All Peer-Reviewed Publications

Reliance on seasonal wild harvests of the edible long-horned grasshopper Ruspolia differens (Serville) (Orthoptera: Tettigoniidae) needs to be broken through developing efficient mass rearing protocols. This study aimed at boosting productivity of laboratory colonies of R. differens through understanding ways of minimising cannibalism, selecting suitable oviposition substrates and enhancing egg development and hatchability. Firstly, we investigated the extent of cannibalism in a colony of R. differens relative to total mortality, sex, diurnality, growth stage, body parts eaten and visual barriers (presence/absence of cardboard egg trays). R. differens cadavers recovered from cages with/without the egg trays were scored for cause of …

Nnbmss: A Novel And Fast Method For Model Structure Selection, Amaury Lendasse, Kallin Khan, Edward Ratner

Engineering Management and Systems Engineering Faculty Research & Creative Works

In This Paper, We Present a New Method to Perform Model Structure Selection. This Proposed Method Can Be Used to Select the Complexity of Any Continuous Regression Method. We Also Present an Asymptotic Mathematical Proof of the Proposed Method and the New Method is Illustrated on a Benchmark. Compared to the Well-Known 10-Fold Cross-Validation, the Computational Time Associated to Our New Method is Approximately Divided by a Factor 8 as Illustrated on the Benchmark.

A Multi-Elm Model For Incomplete Data, Baichuan Chi, Amaury Lendasse, Edward Ratner, Renjie Hu

Engineering Management and Systems Engineering Faculty Research & Creative Works

This Paper Presents a Novel Model of Extreme Learning Machines (Elms) for Incomplete Data. Elms Are Fast Accurate Randomized Neural Networks. Nevertheless, Elm Can Only Be Applied on the Complete Dataset. Therefore, a Novel Multi-Elm Model for Incomplete Data is Proposed, Consisting of Multiple Secondary Elms and One Primary Elm. the Secondary Elms Are Approximating the Primary Elm's Hidden Neurons' Outputs for the Data with Missing Values. as Summarized in the Experimental Section, This Model Can Be Applied on Data with Any Missing Patterns, without using Imputations and Can Outperform the Traditional Imputation Methods within a Reasonable Fraction of Missing …

Machine Learning For Measuring And Analyzing Online Social Communications, Chris Bronk, Amaury Lendasse, Peggy Lindner, Dan S. Wallach, Barbara Hammer

Engineering Management and Systems Engineering Faculty Research & Creative Works

In This Paper, We Propose a Framework for Application of a Novel Machine Learning-Based System for Analyzing Online Social Communications. as an Example, We Are Targeting Anti-Semitic Graphical Memes Posted to Social Media. We Presented Very Promising Preliminary Results on a Facebook Dataset that Consists of a Total of 10000 Labeled Memes. We Can Conclude that Machine Learning Will Soon Be Able to Successfully Analyze and Monitor Complex Social Communications.

Highly Porous Ceramic And Metal Aerogels From Xerogel Powder Precursors, And Methods For Thier Production And Use, Nicholas Leventis, Chariklia Sotiriou-Leventis, Malik Adnan Saeed, Parwani Rewatkar, Tahereh Taghvaee

Patents

The present invention discloses novel methods for producing highly porous ceramic and/or metal aerogel monolithic objects that are hard, sturdy, and resistant to high temperatures. These methods comprise preparing nanoparticulate oxides of metals and/or metalloids via a step of vigorous stirring to prevent gelation, preparing polymer-modified xerogel powder compositions by reacting said nanoparticulate oxides with one or more polyfunctional monomers, compressing said polymer-modified xerogel powder compositions into shaped compacts, and carbothermal conversion of the shaped xerogel compacts via pyrolysis to provide the highly porous ceramic and/or metal aerogel monolithic objects that have the same shapes as their corresponding xerogel compact …

Metal Foils With Ordered Crystal Structure And Method For Producing Metal Foils, Jay A. Switzer

Patents

A method for producing a metal foil comprising depositing metal onto an oxidizable substrate to form a metal film on the substrate; oxidizing the substrate at an interface between the metal film and the substrate; and removing the metal film from the substrate to yield a metal foil. A method for forming a thin metal film comprising pre-polarizing a single-crystal Si substrate by application of a potential which is negative of a potential at which Si oxidizes, which pre-polarization occurs in the presence of metal ions to form metal growth nucleation sites on the substrate, followed by application of a …

Microsphere Based Patterning Of Metal Optic/Plasmonic Sensors Including Fiber Based Sensors, Edward C. Kinzel, Mahmoud Almasri, Chuang Qu, Ibrahem Jasim, Jiayu Liu

Patents

A fiber-based sensor and a method of forming a fiber-based sensor using microsphere lithography techniques in which a microsphere array is applied to a surface of a tip of an optical fiber to provide for microsphere lithography fabrication of a desired pattern on the tip of the optical fiber. The characteristics of the pattern define sensing capabilities of the sensor to provide for chemical and/or biological sensing.

Frequency-Selective Metasurface Integrated Uncooled Microbolometers, Mahmoud Almasri, Edward C. Kinzel

Patents

A metasurface integrated microbolometer having a sensing layer (e.g., SixGeyOI-x-y ). The presence of the metasurface provides selectivity with respect to wavelength, polarization and angle-of-incidence. The presence of the metasurface into the microbolometer affects conversion of electromagnetic to thermal energy, thermal response, electrical integration of the micro bolometer, and the tradeoff between resistivity and temperature coefficient of resistance, thereby allowing the ability to obtain a sensing with high temperature coefficient of resistance with lower resistivity values than that of films without the metasurface. The presence of the metasurface removes the need for a Fabry-Perot cavity.

Porous Polymer Compositions For The Synthesis Of Monolithic Bimodal Microporous/Macroporous Carbon Compositions Useful For Selective Co2 Sequestration, Nicholas Leventis, Chariklia Sotiriou-Leventis, Malik Adnan Saeed

Patents

The present invention discloses novel porous polymeric compositions comprising random copolymers of amides, imides, ureas, and carbamic-anhydrides, useful for the synthesis of monolithic bimodal microporous/macroporous carbon aerogels. It also discloses methods for producing said microporous/macroporous carbon aerogels by the reaction of a polyisocyanate compound and a polycarboxylic acid compound, followed by pyrolytic carbonization, and by reactive etching with CO2 at elevated temperatures. Also disclosed are methods for using the microporous/macroporous carbon aerogels in the selective capture and sequestration of carbon dioxide.

Real-Time Overhead Power Line Sag Monitoring, Jie Huang, Rui Bo

Patents

System and method for determining real-time sag and shape information of an electrical power line based on strain distribution along a length of an optical fiber associated with the power line. An embedded fiber coupled to an overhead transmission line measures strain using the backscatter of an optical signal, the optical signal is then interrogated using an interferometer.

Zeolite Monolith Compositions And Methods For The Catalytic Cracking Of Alkanes, Ali A. Rownaghi, Xin Li, Fateme Rezaei

Patents

Porous zeolite monolith compositions for the catalytic cracking of alkanes. The compositions may be prepared layer by layer using a 3D printer such that the compositions comprise a plurality of micropores and a plurality of mesopores and may be characterized by macro-meso-microporosity.

Social Work And Artificial Intelligence: Into The Matrix, Lauri Goldkind

Social Service Faculty Publications

No abstract provided.

Sentiment Analysis Of Long-Term Social Data During The Covid-19 Pandemic, Sophanna Ek, Marco Curci, Xiaokun Yang, Beiyu Lin, Pinchao Liu, Hailu Xu

Computer Science Faculty Publications

The COVID-19 pandemic has bringing the “infodemic” in the social media worlds. Various social platforms play a significant role in instantly acquiring the latest updates of the pandemic. Social media such as Twitter and Facebook produce vast amounts of posts related to the virus, vaccines, economics, and politics. In order to figure out how public opinion and sentiments are expressed during the pandemic, this work analyzes the long-term social posts from social media and conducts sentiment analysis on tweets within 12 months. Our findings show the trend topics of long-term social communities during the pandemic and express people’s attitudes towards …

Endobariatric Procedures For Obesity: Clinical Indications And Available Options., Hemant Goyal, Jonathan Kopel, Abhilash Perisetti Md, Rupinder Mann, Aman Ali, Benjamin Tharian, Shreyas Saligram, Sumant Inamdar

Other Specialties

Obesity remains a growing public health epidemic that has increased healthcare costs and related comorbidities. Current treatment guidelines encourage a multidisciplinary approach starting from patient selection, interventions, and long-term follow-up to maintain weight loss. However, these conservative interventions are largely ineffective at reducing body weight due to low adherence to the treatment regimen. Recently, endoscopic bariatric therapies have become an attractive alternative to traditional invasive bariatric surgeries due to their improved efficacy, safety, and cost-effectiveness. Endoscopic bariatric therapies include intragastric balloon placement, endoscopic sleeve gastroplasty, gastric bypass revision, and aspiration therapy. These procedures fall into two separate categories depending on …

Thermal Mapping Of Metal Casting Mold Using High Resolution Distributed Fiber-Optic Sensors, Muhammad Roman, Damilola Balogun, Chen Zhu, Laura Bartlett, Ronald J. O'Malley, Rex Gerald, Jie Huang

PSMRC Faculty Research

This article reports a technique to embed optical fiber into a copper mold plate for generating high-density thermal maps of the mold during the process of metal casting. The temperature measurements were based on acquiring and interpreting Rayleigh backscattering (RBS) signals from embedded fiber, using the interrogation technique of optical frequency domain reflectometry (OFDR). The instrumented mold plate was used to perform a cast-iron dip test and a steel dip test in a 200 lb induction furnace. The maximum temperatures recorded by the embedded fiber-optic sensors were 469 degrees C and 388 degrees C in the cast-iron and steel dip …

New Amphibian And Reptile Distribution Records From Eastern South Dakota, Usa, Drew R. Davis

School of Earth, Environmental, & Marine Sciences Faculty Publications

Over recent years, the continued collection of voucher specimens has helped to better document the distributions of South Dakota’s amphibians and reptiles. Despite large increases in our knowledge of these distributions, it remains clear that gaps in our understanding remain. Here, I report 17 new county records of six species of amphibians and reptiles from eastern South Dakota (east of the Missouri River) that are the result of fieldwork conducted in September 2020. The majority of these records are from the northern portions of the James River Lowland, Missouri Coteau, and Drift Plains ecoregions (Bryce et al. 1998), which are …

Phase Diagram, Stability And Magnetic Properties Of Nonlinear Excitations In Spinor Bose-Einstein Condensates, Garyfallia Katsimiga, Simeon I. Mistakidis, P. Schmelcher, P. G. Kevrekidis

Physics Faculty Research & Creative Works

We Present The Phase Diagram, The Underlying Stability And Magnetic Properties As Well As The Dynamics Of Nonlinear Solitary Wave Excitations Arising In The Distinct Phases Of A Harmonically Confined Spinor F = 1 Bose-Einstein Condensate. Particularly, It Is Found That Nonlinear Excitations In The Form Of Dark-Dark-Bright Solitons Exist In The Antiferromagnetic And In The Easy-Axis Phase Of A Spinor Gas, Being Generally Unstable In The Former While Possessing Stability Intervals In The Latter Phase. Dark-Bright-Bright Solitons Can Be Realized In The Polar And The Easy-Plane Phases As Unstable And Stable Configurations Respectively; The Latter Phase Can Also Feature …