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Improving Rheological And Thermal Performance Of Gilsonite-Modified Binder With Phase Change Materials, Farshad Saberi K., Yizhuang David Wang, Jenny Liu Oct 2023

Improving Rheological And Thermal Performance Of Gilsonite-Modified Binder With Phase Change Materials, Farshad Saberi K., Yizhuang David Wang, Jenny Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Gilsonite, as a type of natural asphalt binder, has been used to improve the high-temperature performance of regular asphalt binders. However, the addition of Gilsonite may compromise binders' low-temperature thermal cracking resistance. In this research, polyethylene glycol (PEG), as one type of the phase change materials (PCMs), was used as an innovative material to balance the impacts of Gilsonite on high and low performance of asphalt binders. The dosages of Gilsonite and PEG were first determined based on the materials' rheological behaviors at low temperatures. The performance of the PEG-Gilsonite-modified binder was then fully evaluated in terms of the resistance …


Catching Elusive Depression Via Facial Micro-Expression Recognition, Xiaohui Chen, Tony Tie (T.) Luo Oct 2023

Catching Elusive Depression Via Facial Micro-Expression Recognition, Xiaohui Chen, Tony Tie (T.) Luo

Computer Science Faculty Research & Creative Works

Depression is a common mental health disorder that can cause consequential symptoms with continuously depressed mood that leads to emotional distress. One category of depression is Concealed Depression, where patients intentionally or unintentionally hide their genuine emotions through exterior optimism, thereby complicating and delaying diagnosis and treatment and leading to unexpected suicides. In this article, we propose to diagnose concealed depression by using facial micro-expressions (FMEs) to detect and recognize underlying true emotions. However, the extremely low intensity and subtle nature of FMEs make their recognition a tough task. We propose a facial landmark-based Region-of-Interest (ROI) approach to address the …


Rilem Tc 266-Mrp: Round-Robin Rheological Tests On High Performance Mortar And Concrete With Adapted Rheology—Evaluating Structural Build-Up At Rest Of Mortar And Concrete, Sofiane Amziane, Kamal Khayat, Mohammed Sonebi, Arnaud Perrot Oct 2023

Rilem Tc 266-Mrp: Round-Robin Rheological Tests On High Performance Mortar And Concrete With Adapted Rheology—Evaluating Structural Build-Up At Rest Of Mortar And Concrete, Sofiane Amziane, Kamal Khayat, Mohammed Sonebi, Arnaud Perrot

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This Paper Presents the Results of a Round-Robin Testing Program Undertaken by RILEM TC-266-Measuring Rheological Properties of Cement-Based Materials in May 2018 at the Université D'Artois in Bethune, France. Seven Types of Rheometers Were Compared; They Consisted of Four ICAR Rheometers, Viskomat XL Rheometer, EBT-V Rheometer, Sliding Pipe Rheometer (SLIPER), RheoCAD Rheometer, and 4SCC Rheometer, as Well as the Plate Test. This Paper Discusses the Results of the Evolution of the Static Yield Stress at Rest of Three Mortar and Five Concrete Mixtures that Were Determined using Two ICAR Rheometers, Viskomat XL, and EBT-V Rheometers, as Well as the Plate …


Affine Image Registration Of Arterial Spin Labeling Mri Using Deep Learning Networks, Zongpai Zhang, Huiyuan Yang, Yanchen Guo, Nicolas R. Bolo, Matcheri Keshavan, Eve Derosa, Adam K. Anderson, David C. Alsop, Lijun Yin, Weiying Dai Oct 2023

Affine Image Registration Of Arterial Spin Labeling Mri Using Deep Learning Networks, Zongpai Zhang, Huiyuan Yang, Yanchen Guo, Nicolas R. Bolo, Matcheri Keshavan, Eve Derosa, Adam K. Anderson, David C. Alsop, Lijun Yin, Weiying Dai

Computer Science Faculty Research & Creative Works

Convolutional neural networks (CNN) have demonstrated good accuracy and speed in spatially registering high signal-to-noise ratio (SNR) structural magnetic resonance imaging (sMRI) images. However, some functional magnetic resonance imaging (fMRI) images, e.g., those acquired from arterial spin labeling (ASL) perfusion fMRI, are of intrinsically low SNR and therefore the quality of registering ASL images using CNN is not clear. In this work, we aimed to explore the feasibility of a CNN-based affine registration network (ARN) for registration of low-SNR three-dimensional ASL perfusion image time series and compare its performance with that from the state-of-the-art statistical parametric mapping (SPM) algorithm. The …


Mantle Flow Underneath The South China Sea Revealed By Seismic Anisotropy, Fansheng Kong, Rui Gao, Stephen S. Gao, Kelly H. Liu, Weiwei Ding, Xiongwei Niu, Aiguo Ruan, Pingchuan Tan, Jianke Fan, Shaoping Lu, Zhengyi Tong, Liqun Cheng, Wenfei Gong, Yanghui Zhao Oct 2023

Mantle Flow Underneath The South China Sea Revealed By Seismic Anisotropy, Fansheng Kong, Rui Gao, Stephen S. Gao, Kelly H. Liu, Weiwei Ding, Xiongwei Niu, Aiguo Ruan, Pingchuan Tan, Jianke Fan, Shaoping Lu, Zhengyi Tong, Liqun Cheng, Wenfei Gong, Yanghui Zhao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

It Has Long Been Established that Plastic Flow in the Asthenosphere Interacts Constantly with the overlying Lithosphere and Plays a Pivotal Role in Controlling the Occurrence of Geohazards Such as Earthquakes and Volcanic Eruptions. Unfortunately, Accurately Characterizing the Direction and Lateral Extents of the Mantle Flow Field is Notoriously Difficult, Especially in Oceanic Areas Where Deployment of Ocean Bottom Seismometers (OBSs) is Expensive and Thus Rare. in This Study, by Applying Shear Wave Splitting Analyses to a Dataset Recorded by an OBS Array that We Deployed between Mid-2019 and Mid-2020 in the South China Sea (SCS), We Show that the …


Effect Of Rotation On Mixing Efficiency In Homogeneous Stratified Turbulence Using Unforced Direct Numerical Simulations, Matthew Klema, S. Karan Venayagamoorthy, Annick Pouquet, Duane Rosenberg, Raffaele Marino Oct 2023

Effect Of Rotation On Mixing Efficiency In Homogeneous Stratified Turbulence Using Unforced Direct Numerical Simulations, Matthew Klema, S. Karan Venayagamoorthy, Annick Pouquet, Duane Rosenberg, Raffaele Marino

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Diapycnal (irreversible) mixing is analyzed using thirty direct numerical simulations (at 1024 3 resolution) of homogeneous rotating stratified turbulence (RST) in the absence of imposed shear or forcing. The influence of varied rotation and stratification rates on the energetics (in particular the dissipation rates of kinetic and potential energies) is presented. Data is also analyzed within a new parametric framework, using the turbulent Froude and Rossby numbers Frt= ϵ/ Nk, Rot= ϵ/ fk, where k is the turbulent kinetic energy, ϵ its rate of dissipation, N the buoyancy frequency and f the Coriolis parameter. This framework is used to illustrate …


Preface: Special Issue On Turbulence And Mixing In Stratified Flows, S. Karan Venayagamoorthy Oct 2023

Preface: Special Issue On Turbulence And Mixing In Stratified Flows, S. Karan Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.


The Big Cheese ‘Important Person’, Gerald Leonard Cohen Oct 2023

The Big Cheese ‘Important Person’, Gerald Leonard Cohen

Arts, Languages and Philosophy Faculty Research & Creative Works

No abstract provided.


Mixing Rates In Stably Stratified Flows With Respect To The Turbulent Froude Number And Turbulent Scales, Matthew R. Klema, Subhas Karan Venayagamoorthy Oct 2023

Mixing Rates In Stably Stratified Flows With Respect To The Turbulent Froude Number And Turbulent Scales, Matthew R. Klema, Subhas Karan Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this analysis the quantification of diapycnal diffusivity Kρ in stratified flows such as those found in the ocean and atmosphere is explored. There are two simplifications that are routinely made when estimating mixing rates in stably stratified flows. First, a constant value is commonly assumed for the (irreversible) mixing coefficient Γ . Second, dissipation rates of turbulent kinetic energy ϵ are inferred using either the Thorpe (or Ellison) length scales or from microstructure measurements using the isotropy assumption. Data from three independent direct numerical simulations of homogeneous stratified turbulence are used as a testbed to highlight impacts of these …


Mindfulness And Workplace Safety: An Integrative Review, Zihan Liu, Kevin Hoff, Erica Baranski, Galen Snyder, Rhona Flin, Peggy Lindner, Christiane Spitzmueller Oct 2023

Mindfulness And Workplace Safety: An Integrative Review, Zihan Liu, Kevin Hoff, Erica Baranski, Galen Snyder, Rhona Flin, Peggy Lindner, Christiane Spitzmueller

Engineering Management and Systems Engineering Faculty Research & Creative Works

Mindfulness has recently gained popularity in applied settings to enhance workplace safety, especially in safety-critical occupations such as healthcare and construction. In this review, we synthesize existing research across disciplines to establish a theoretical model of mindfulness and safety. Based on 32 empirical studies, we first summarize and critically analyze how mindfulness and safety are conceptualized and operationalized in the literature. We then consolidate empirical findings and conceptual arguments and draw upon the job demands–resources model to propose a theoretical model linking the basic benefits of mindfulness to safety-related job demands. Specifically, we propose that mindfulness (a) improves detection of …


Soil Adsorption Of Heavy Metals To Protect Groundwater Near Refinery Wastewater Discharge Points, Hamid A. Al-Falahi, Ferdous A. Jabir, Muthanna H. Al-Dahhan Oct 2023

Soil Adsorption Of Heavy Metals To Protect Groundwater Near Refinery Wastewater Discharge Points, Hamid A. Al-Falahi, Ferdous A. Jabir, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

This study presents a strategy to manage the discharge of wastewater, which is either partially treated or untreated, to safeguard the groundwater reserves in the region. a case study involving Ad Diwaniyah refinery wastewater disposal into an adjacent desert was utilized to evaluate the influence of soil adsorption on the attenuation of Pb, Cu, and Cd ion concentrations. Investigation of competitive adsorption of heavy metal ions (Pb2+, Cu2+, and Cd2+) in Dolomite-Limestone soil was conducted through batch and column methods. the adsorption behavior of the bivalent metal cations was observed to be pH dependent. However, the competitive extraction of the …


Atomic Insights Into The Structural Properties And Displacement Cascades In Ytterbium Titanate Pyrochlore (Yb2ti2o7) And High-Entropy Pyrochlores, M. Mustafa Azeem, Qingyu Wang Oct 2023

Atomic Insights Into The Structural Properties And Displacement Cascades In Ytterbium Titanate Pyrochlore (Yb2ti2o7) And High-Entropy Pyrochlores, M. Mustafa Azeem, Qingyu Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Pyrochlore oxides ((Formula presented.) are potential nuclear waste substrate materials due to their superior radiation resistance properties. We performed molecular dynamics simulations to study the structural properties and displacement cascades in ytterbium titanate pyrochlore ((Formula presented.)) and high-entropy alloys (HEPy), e.g., (Formula presented.), (Formula presented.), and (Formula presented.). We computed lattice constants (LC) ((Formula presented.)) and threshold displacement energy (Ed). Furthermore, the calculation for (Formula presented.) and ionic radius ((Formula presented.)) were performed by substituting a combination of cations at the A and B sites of the original pyrochlore structure. Our simulation results have demonstrated that the lattice constant is …


System Dynamic Modeling To Study The Impact Of Construction Industry Characteristics And Associated Macroeconomic Indicators On Workforce Size And Labor Retention Rate, Tamima Elbashbishy, Islam H. El-Adaway Oct 2023

System Dynamic Modeling To Study The Impact Of Construction Industry Characteristics And Associated Macroeconomic Indicators On Workforce Size And Labor Retention Rate, Tamima Elbashbishy, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Limited skilled labor has been one of the greatest challenges facing the construction industry. The COVID-19 pandemic has further exaggerated the already strained construction labor market, leading to an additional negative impact. One of the major contributors to skilled labor shortages in construction is the issue of labor retention. Overall, this is a complex and dynamic situation that requires effective and efficient simulation-based techniques to capture the interdependent relationships that affect the performance of the construction labor market. This paper fills this knowledge gap. To this end, the authors used a multistep research methodology that involved (1) identifying factors that …


Interferometry Of Efimov States In Thermal Gases By Modulated Magnetic Fields, G. Bougas, Simeon I. Mistakidis, P. Schmelcher, C. H. Greene, P. Giannakeas Oct 2023

Interferometry Of Efimov States In Thermal Gases By Modulated Magnetic Fields, G. Bougas, Simeon I. Mistakidis, P. Schmelcher, C. H. Greene, P. Giannakeas

Physics Faculty Research & Creative Works

We Demonstrate That An Interferometer Based On Modulated Magnetic Field Pulses Enables Precise Characterization Of The Energies And Lifetimes Of Efimov Trimers Irrespective Of The Magnitude And Sign Of The Interactions In Rb85 Thermal Gases. Despite Thermal Effects, Interference Fringes Develop When The Dark Time Between The Pulses Is Varied. This Enables The Selective Excitation Of Coherent Superpositions Of Trimer, Dimer, And Free-Atom States. The Interference Patterns Possess Two Distinct Damping Timescales At Short And Long Dark Times That Are Either Equal To Or Twice As Long As The Lifetime Of Efimov Trimers, Respectively. Specifically, This Behavior At Long Dark …


A Holistic Approach To Include Sic And Design The Optimal Extrudate Catalyst For Hydrogen Production–Reforming Routes, Ali M. Alkadhem, Fernanda Tavares, Natalia Realpe, Gontzal Lezcano, Arief Yudhanto, Mohammad Subah, Vasco Manaças, Jacek Osinski, Gilles Lubineau, Pedro Castaño Oct 2023

A Holistic Approach To Include Sic And Design The Optimal Extrudate Catalyst For Hydrogen Production–Reforming Routes, Ali M. Alkadhem, Fernanda Tavares, Natalia Realpe, Gontzal Lezcano, Arief Yudhanto, Mohammad Subah, Vasco Manaças, Jacek Osinski, Gilles Lubineau, Pedro Castaño

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Reforming processes are the backbone of hydrogen production routes, given the flexibility of their feedstock, such as methane, carbon dioxide, ammonia, waste plastics, or biomass. Heat transfer is a drawback at the industrial scale, reducing efficiency. We incorporate SiC in the technical composite, extrudate catalyst and develop a holistic approach to optimize and understand the effect of each constituent and its mixtures. We apply Ni-Ce as an active phase, bentonite or kaolin as a binder, alumina as a filler, and carborundum as the heat-transport carrier. We characterize the extrudate catalysts using various techniques, including crushing strength and thermal conductivity. We …


Enhancing Heat Transfer Performance In Simulated Fischer–Tropsch Fluidized Bed Reactor Through Tubes Ends Modifications, Laith S. Sabri, Abbas J. Sultan, Jamal M. Ali, Hasan Shakir Majdi, Muthanna H. Al-Dahhan Oct 2023

Enhancing Heat Transfer Performance In Simulated Fischer–Tropsch Fluidized Bed Reactor Through Tubes Ends Modifications, Laith S. Sabri, Abbas J. Sultan, Jamal M. Ali, Hasan Shakir Majdi, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Fluidized bed reactors are essential in a wide range of industrial applications, encompassing processes such as Fischer–Tropsch synthesis and catalytic cracking. The optimization of performance and reduction in energy consumption in these reactors necessitate the use of efficient heat transfer mechanisms. The present work examines the considerable impact of tube end geometries, superficial gas velocity, and radial position on heat transfer coefficients within fluidized bed reactors. It was found that the tapered tube end configurations have been empirically proven to improve energy efficiency in fluidized bed reactors significantly. For example, at a superficial gas velocity of 0.4 m/s, the tapered …


Modulation Of Electrocatalytic Activity By Tuning Anion Electronegativity: Case Study With Copper Chalcogenides, Harish Singh, David Prendergast, Manashi Nath Oct 2023

Modulation Of Electrocatalytic Activity By Tuning Anion Electronegativity: Case Study With Copper Chalcogenides, Harish Singh, David Prendergast, Manashi Nath

Chemistry Faculty Research & Creative Works

Anion-tuning in metallic chalcogenides has been shown to have a significant impact on their electrocatalytic ability for overall water splitting. In this article, copper-based chalcogenides (Cu2 X, X= O, S, Se, and Te) have been systematically studied to examine the effect of decreasing anion electronegativity and increasing covalency on the electrocatalytic performance. Among the copper chalcogenides, Cu2Te has the highest oxygen evolution reaction (OER) activity and can sustain high current density of 10 and 50 mA cm−2 for 12 h. The difference in intrinsic catalytic activity of these chalcogenide surfaces have been also probed through density functional theory calculations, which …


Switching Of Control Mechanisms During The Rapid Solidification Of A Melt Pool, Yijia Gu, Jiandong Yuan, Lianyi Chen Oct 2023

Switching Of Control Mechanisms During The Rapid Solidification Of A Melt Pool, Yijia Gu, Jiandong Yuan, Lianyi Chen

Materials Science and Engineering Faculty Research & Creative Works

The Solidification of Alloys is Typically Controlled by Solute Diffusion Due to the Solute Partitioning Happening at the Solid-Liquid Interface. in This Study, We Show that the Switching from Solute Diffusion-Controlled Growth to Thermal Diffusion-Controlled Growth May Happen at the Solidification Front during Rapid Solidification Processes of Alloys Such as Additive Manufacturing using a Phase-Field Model. the Switching is Found to Be Triggered by the Cooling of the Solid-Liquid Interface When It Becomes Colder Than the Solidus Temperature. the Switching Introduces a Sudden Jump of Growth Velocity, an Increase in Solute Concentration, and the Refining of the Resulting Microstructures. All …


On The Prediction Of The Mechanical Properties Of Limestone Calcined Clay Cement: A Random Forest Approach Tailored To Cement Chemistry, Taihao Han, Bryan K. Aylas-Paredes, Jie Huang, Ashutosh Goel, Narayanan Neithalath, Aditya Kumar Oct 2023

On The Prediction Of The Mechanical Properties Of Limestone Calcined Clay Cement: A Random Forest Approach Tailored To Cement Chemistry, Taihao Han, Bryan K. Aylas-Paredes, Jie Huang, Ashutosh Goel, Narayanan Neithalath, Aditya Kumar

Materials Science and Engineering Faculty Research & Creative Works

Limestone calcined clay cement (LC3) is a sustainable alternative to ordinary Portland cement, capable of reducing the binder's carbon footprint by 40% while satisfying all key performance metrics. The inherent compositional heterogeneity in select components of LC3, combined with their convoluted chemical interactions, poses challenges to conventional analytical models when predicting mechanical properties. Although some studies have employed machine learning (ML) to predict the mechanical properties of LC3, many have overlooked the pivotal role of feature selection. Proper feature selection not only refines and simplifies the structure of ML models but also enhances these models' prediction performance and interpretability. This …


Mechanism Underlying Effect Of Expansive Agent And Shrinkage Reducing Admixture On Mechanical Properties And Fiber-Matrix Bonding Of Fiber-Reinforced Mortar, Kamran Aghaee, Taihao Han, Aditya Kumar, Kamal Khayat Oct 2023

Mechanism Underlying Effect Of Expansive Agent And Shrinkage Reducing Admixture On Mechanical Properties And Fiber-Matrix Bonding Of Fiber-Reinforced Mortar, Kamran Aghaee, Taihao Han, Aditya Kumar, Kamal Khayat

Materials Science and Engineering Faculty Research & Creative Works

Expansive agent (EA) and shrinkage reducing admixture (SRA) are utilized to reduce shrinkage and risk of cracking in concrete. EA compensates shrinkage by initial expansion, and SRA reduces surface tension in the pore fluid. Although EA and SRA effectively reduce shrinkage, they can impair micro-structure of concrete at high contents. The shrinkage reduction effect of EA and SRA is well known; however, there is limited knowledge about their negative effect on microstructure and fiber matrix interfacial transition zone (ITZ). The current study explores the effect of using 10 % CaO-based EA, 2 % SRA, and their combination on mechanical, shrinkage, …


The Investigation Of A Likely Scenario For Natural Tornado Genesis And Evolution From An Initial Instability Profile, Alexios Nicolas Philippou, Kakkattukuzhy M. Isaac Oct 2023

The Investigation Of A Likely Scenario For Natural Tornado Genesis And Evolution From An Initial Instability Profile, Alexios Nicolas Philippou, Kakkattukuzhy M. Isaac

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A likely mechanism for the little-understood tornado genesis is proposed and its numerical implementation is presented. The Burgers-Rott vortex with its axis in the vertical direction is introduced as an instability mechanism, and the flow field then evolves under the influence of the atmospheric pressure, temperature and density variations with altitude. Buoyancy effects are implemented using the Boussinesq model. Results are presented and discussed for a set of conditions including mesh type and size, different turbulence models, and a few different boundary conditions. Post-processed results of the transient simulations including animations contain a wealth of information to help analyze tornado …


Semi-Annual Progress Report #12, Missouri University Of Science And Technology. Inspire - University Transportation Center Sep 2023

Semi-Annual Progress Report #12, Missouri University Of Science And Technology. Inspire - University Transportation Center

Semi-Annual Progress Reports

No abstract provided.


Edge-Computing-Driven Internet Of Things: A Survey, Linghe Kong, Jinlin Tan, Junqin Huang, Guihai Chen, Shuaitian Wang, Xi Jin, Peng Zeng, Muhammad Khan, Sajal K. Das Sep 2023

Edge-Computing-Driven Internet Of Things: A Survey, Linghe Kong, Jinlin Tan, Junqin Huang, Guihai Chen, Shuaitian Wang, Xi Jin, Peng Zeng, Muhammad Khan, Sajal K. Das

Computer Science Faculty Research & Creative Works

The Internet of Things (IoT) is impacting the world's connectivity landscape. More and more IoT devices are connected, bringing many benefits to our daily lives. However, the influx of IoT devices poses non-trivial challenges for the existing cloud-Based computing paradigm. in the cloud-Based architecture, a large amount of IoT data is transferred to the cloud for data management, analysis, and decision making. It could not only cause a heavy workload on the cloud but also result in unacceptable network latency, ultimately undermining the benefits of cloud-Based computing. to address these challenges, researchers are looking for new computing models for the …


Is Performance Fairness Achievable In Presence Of Attackers Under Federated Learning?, Ashish Gupta, George Markowsky, Sajal K. Das Sep 2023

Is Performance Fairness Achievable In Presence Of Attackers Under Federated Learning?, Ashish Gupta, George Markowsky, Sajal K. Das

Computer Science Faculty Research & Creative Works

In the last few years, Federated Learning (FL) has received extensive attention from the research community because of its capability for privacy-preserving, collaborative learning from heterogeneous data sources. Most FL studies focus on either average performance improvement or the robustness to attacks, while some attempt to solve both jointly. However, the performance disparities across clients in the presence of attackers have largely been unexplored. In this work, we propose a novel Fair Federated Learning scheme with Attacker Detection capability (abbreviated as FFL+AD) to minimize performance discrepancies across benign participants. FFL+AD enables the server to identify attackers and learn their malign …


Is Performance Fairness Achievable In Presence Of Attackers Under Federated Learning?, Ashish Gupta, George Markowsky, Sajal K. Das Sep 2023

Is Performance Fairness Achievable In Presence Of Attackers Under Federated Learning?, Ashish Gupta, George Markowsky, Sajal K. Das

Computer Science Faculty Research & Creative Works

In the last few years, Federated Learning (FL) has received extensive attention from the research community because of its capability for privacy-preserving, collaborative learning from heterogeneous data sources. Most FL studies focus on either average performance improvement or the robustness to attacks, while some attempt to solve both jointly. However, the performance disparities across clients in the presence of attackers have largely been unexplored. in this work, we propose a novel Fair Federated Learning scheme with Attacker Detection capability (abbreviated as FFL+AD) to minimize performance discrepancies across benign participants. FFL+AD enables the server to identify attackers and learn their malign …


From A Single Grain To Microstructure: How Explosive Grains Interact Under Shock Compression, Lawrence Salvati, Siva Kumar Valluri, Dana D. Dlott Sep 2023

From A Single Grain To Microstructure: How Explosive Grains Interact Under Shock Compression, Lawrence Salvati, Siva Kumar Valluri, Dana D. Dlott

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We studied the effect of varying the HMX concentration in a plastic-bonded explosive (PBX) by analyzing the time-dependent thermal emission with short (4 ns) duration shocks that produced pressures of about 20 GPa. We found that the HMX tended to aggregate even at the lowest concentrations. Once the cluster size reached about 15 μm, at 30 wt.%, the cluster size started increasing more dramatically, but energy release during deflagration reached a plateau. These observations are consistent with the idea that the clusters act as a limiting factor for hot spot criticality, possibly due to heat loss mechanisms such as conduction …


Porosity: The Key To Initiating Metallic Composite Particles Under Shock Compression, Siva Kumar Valluri, Edward L. Dreizin, Dana D. Dlott Sep 2023

Porosity: The Key To Initiating Metallic Composite Particles Under Shock Compression, Siva Kumar Valluri, Edward L. Dreizin, Dana D. Dlott

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The use of metallic composites as additives can potentially improve the energy density of explosives. Before employing them as additives it is imperative to design composites with physically separated metal fuel and oxidizer that can combust on short time scales, tens of nanoseconds, similar to high-performance molecular explosives. Towards that end, sensitizing composite powder particles to shock compression is crucial. In the current work, particle porosity is explored as means to induce hotspot formation within the particle through pore-collapse. Particles of two porous powders, Al-MoO3-KNO3 (equivalence ratio 3) and Al-CuO (equivalence ratio 4) prepared by arrested reactive milling with emulsion …


Seeing Inside Shocked Plastic-Bonded Explosives, Dhanalakshmi Sellan, Lawrence Salvati, Siva Kumar Valluri, Dana D. Dlott, Xuan Zhou Sep 2023

Seeing Inside Shocked Plastic-Bonded Explosives, Dhanalakshmi Sellan, Lawrence Salvati, Siva Kumar Valluri, Dana D. Dlott, Xuan Zhou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A new method is described to study how microstructures within a plastic-bonded explosive (PBX) interact with shock waves to produce hot spots, and to identify the critical hot spots that grow into a deflagration. A unique feature of this method is that it allows us to see every crystal in the PBX during the shock. We used an HMX-based PBX fabricated into a wafer about one crystal thick so there are no crystals hidden from view. The wafer is embedded in a transparent polymer in a traveling wave geometry, and a microscope with a laser flyer launcher and a nanosecond …


Common Ground Newsletter Fall 2023, Missouri University Of Science And Technology Sep 2023

Common Ground Newsletter Fall 2023, Missouri University Of Science And Technology

Common Ground

- Free-Format Education

- S&T student selected as national ASCE ambassador

- Heart of a servant

- Exploring history, architecture of Chicago


Robotic Inspection Of Infrastructure Using Vision, Gpr, And Impact-Echo Sensors, Jizhong Xiao Sep 2023

Robotic Inspection Of Infrastructure Using Vision, Gpr, And Impact-Echo Sensors, Jizhong Xiao

INSPIRE Archived Webinars

Bridges, dams, highways, and tunnels in the U.S. are reaching their life expectancy, and thus have imperative needs for routine inspection and maintenance to ensure sustainability. It is reported that 42% of over 600,000 highway bridges in the National Bridge Inventory (NBI) have exceeded their design life of 50 years, and 42,951 bridges are rated in poor condition and classified as "structurally deficient". To inspect the structurally integrity of bridges, the inspectors also need to detect subsurface defects (i.e., delamination, voids) using NDE instruments such as GPR and impact-echo (IE) device at difficult to access components (i.e., pier, bottom side …