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Articles 1561 - 1590 of 21777

Full-Text Articles in Engineering

A Review On Liquid Flow Through Low-Density Fibrous Porous Media, Hossein Abedsoltan Dec 2023

A Review On Liquid Flow Through Low-Density Fibrous Porous Media, Hossein Abedsoltan

Chemical and Biochemical Engineering Faculty Research & Creative Works

This review focuses on studying liquid flow through low-density fibrous porous media, particularly tissue grades of papers. It discusses experimental designs, factors affecting liquid flow, and various versions of the Lucas-Washburn equation and permeability expressions used to estimate liquid flow in these media. While a comprehensive model for liquid flow in these materials is lacking due to their structural complexity, numerous experimental methods have been developed to determine absorption properties, particularly for wiping and cleaning liquids. The review covers these methods, many of which are proposed by standard organizations. It is a valuable reference for scientists interested in understanding the …


Covid-19 And The Chemical Industry: Impacts, Challenges, And Opportunities, Hossein Abedsoltan Dec 2023

Covid-19 And The Chemical Industry: Impacts, Challenges, And Opportunities, Hossein Abedsoltan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The COVID-19 pandemic imposed unparalleled challenges for the chemical industry, leading to disruptions in supply chains and demand dynamics. This period of crisis tested the adaptability and resilience of global chemical companies. Despite the challenges, the chemical industry exhibited remarkable innovation, collaboration, and adaptability. It demonstrated its capacity to respond swiftly and effectively to societal needs. Key lessons emerged, emphasizing the importance of diversifying supply chains, implementing scenario planning, and embracing digitalization for enhanced preparedness. As the world progresses toward recovery, the chemical industry is poised to leverage the valuable lessons learned. Industry 4.0 adoption, agile decision-making, and collaborative efforts …


Comparative Evaluation Of Caries Prevalence Among Group Of Egyptian Adolescents Using Dmfs And Icdasii Methods: A Cross-Sectional Study, Mohamed H. Zaazou, Dalia Y. Zaki, Ali Abdelnabi, Tamer M. Hamdy, Reham S. Saleh, Shahinaz N. Hassan, Zeinab M. Zaki, Lamiaa M. Moharam Dec 2023

Comparative Evaluation Of Caries Prevalence Among Group Of Egyptian Adolescents Using Dmfs And Icdasii Methods: A Cross-Sectional Study, Mohamed H. Zaazou, Dalia Y. Zaki, Ali Abdelnabi, Tamer M. Hamdy, Reham S. Saleh, Shahinaz N. Hassan, Zeinab M. Zaki, Lamiaa M. Moharam

Chemical and Biochemical Engineering Faculty Research & Creative Works

Background: Limited data is available regarding the prevalence of dental caries as a chronic disease among adolescents using different caries assessment indices. The aim of this study was to compare and describe the prevalence of dental caries among group of Egyptian students using two caries assessment indices: DMFS and ICDAS II. Methods: This descriptive, cross-sectional epidemiological study included 2760 public secondary school students with age range from 15 to 18 years with permanent dentition and good general health. Presence of; retained teeth, congenital or developmental anomalies in the permanent dentition, orthodontic treatments, systematic conditions, smoking and general health problems were …


Drinking-Water Fluoridation As An Example Of The Nurse + Engineer Fostering Informed Decisions And Actions, Daniel B. Oerther, Sarah Oerther Dec 2023

Drinking-Water Fluoridation As An Example Of The Nurse + Engineer Fostering Informed Decisions And Actions, Daniel B. Oerther, Sarah Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.


Atmospheric-Moisture-Induced Polyacrylate Hydrogels For Hybrid Passive Cooling, Roisul Hasan Galib, Yanpei Tian, Yue Lei, Saichao Dang, Xiaole Li, Arief Yudhanto, Gilles Lubineau, Qiaoqiang Gan Dec 2023

Atmospheric-Moisture-Induced Polyacrylate Hydrogels For Hybrid Passive Cooling, Roisul Hasan Galib, Yanpei Tian, Yue Lei, Saichao Dang, Xiaole Li, Arief Yudhanto, Gilles Lubineau, Qiaoqiang Gan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Heat stress is being exacerbated by global warming, jeopardizing human and social sustainability. As a result, reliable and energy-efficient cooling methods are highly sought-after. Here, we report a polyacrylate film fabricated by self-moisture-absorbing hygroscopic hydrogel for efficient hybrid passive cooling. Using one of the lowest-cost industrial materials (e.g., sodium polyacrylate), we demonstrate radiative cooling by reducing solar heating with high solar reflectance (0.93) while maximizing thermal emission with high mid-infrared emittance (0.99). Importantly, the manufacturing process utilizes only atmospheric moisture and requires no additional chemicals or energy consumption, making it a completely green process. Under sunlight illumination of 800 W …


Stochastic Modeling Of Decarbonizing Strategy, Policy, And Market-Induced Incentives For The Us Electricity Sector, Jessica W.A. Azure, Samuel Frimpong, Mahelet G. Fikru Dec 2023

Stochastic Modeling Of Decarbonizing Strategy, Policy, And Market-Induced Incentives For The Us Electricity Sector, Jessica W.A. Azure, Samuel Frimpong, Mahelet G. Fikru

Mining Engineering Faculty Research & Creative Works

In line with the global pursuit of achieving net-zero carbon emissions, integrating carbon capture and storage (CCS) and renewable energy (RE) technologies is important in power production. This study evaluates the profitability of CCS and RE technologies as alternative ways of achieving climate change goals. While past research focused on costs, technological advancements, and capture methods, there is a need for more studies on assessing the financial feasibility of these climate change solutions under uncertain conditions, alongside specific performance goals and strategies to entice power producers. Using a comprehensive framework featuring deterministic and stochastic modeling approaches, this research explores the …


Performance Of Co2-Cured Alkali-Activated Slag Pastes During Curing And Exposure, Yubin Jun, Seong Ho Han, Jae Hong Kim Dec 2023

Performance Of Co2-Cured Alkali-Activated Slag Pastes During Curing And Exposure, Yubin Jun, Seong Ho Han, Jae Hong Kim

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigated the efficiency of CO2 curing in blast-furnace slag pastes activated with three concentrations of KOH solution (3, 4, and 5 M). The CO2 curing was applied into the alkali-activated slag paste for 3 days. The CO2-cured pastes were subjected to subsequent curing in a water bath or exposed to seawater. The mechanical properties and characteristics of the reaction products were compared. Full strength can be obtained within 3 days of the early CO2 curing. The strength remained almost constant regardless of the activator concentration. The CO2-cured samples produced more CaCO …


The Role Of Atomic Layer Deposited Coatings On Lithium-Ion Transport: A Comprehensive Study, Yufang He, Hiep Pham, Xinhua Liang, Jonghyun Park Dec 2023

The Role Of Atomic Layer Deposited Coatings On Lithium-Ion Transport: A Comprehensive Study, Yufang He, Hiep Pham, Xinhua Liang, Jonghyun Park

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Use of Ultrathin Film Coatings Prepared through Atomic Layer Deposition (ALD) Has Become Widespread for Improving Lithium-Ion Diffusivity of Active Particles, Which Plays a Crucial Role in Determining the Rate Capability of Lithium-Ion Batteries (LIBs). in This Study, the Impact of ALD Coating Thickness on Ionic Diffusivity in CeO2-Coated LiMn2O4 (LMO) Cathode Particles is Comprehensively Investigated through First-Principles Calculations by Focusing on the Trade-Offs between the Physical Properties of the Film and its Impact on the Diffusivity of Ions. Our Findings Indicate that Several Physical Factors Affect the Diffusivity of the Coating, Including the Crystal-Amorphous Structure that Depends on …


Microstructure, Mechanical Properties And Oxidation Behavior Of Refractory Multi-Principal Element Alloys By Laser Remelting And Conventional Manufacturing, Visharad Jalan, Seth Crawford, Sung Heng Wu, Frank Liou, Haiming Wen Dec 2023

Microstructure, Mechanical Properties And Oxidation Behavior Of Refractory Multi-Principal Element Alloys By Laser Remelting And Conventional Manufacturing, Visharad Jalan, Seth Crawford, Sung Heng Wu, Frank Liou, Haiming Wen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Refractory multi-principal element alloys (RMPEAs), HfNbTaTiZr, (HfNbTaTiZr)9Cr, and (HfNbTaTiZr)9Al, were manufactured using vacuum arc melting followed by laser remelting to mimic additive manufacturing. the microhardness of the as-cast HfNbTaTiZr, (HfNbTaTiZr)9Cr, and (HfNbTaTiZr)9Al samples after arc melting was measured as 6.20, 7.63, and 6.89 Gpa, respectively. after laser remelting and re-solidification, the hardness increased by ~ 30% for each composition; the hardest was (HfNbTaTiZr)9Cr measured at 9.60 GPa, while the softest was HfNbTaTiZr with a hardness of 8.42 GPa, which was still harder compared to all the other samples. the addition of Al and Cr led to enhanced oxidation resistance for …


Data-Driven Scheme For Joint Estimation Of Direction-Of-Arrival And Frequency With Uniform Linear Array, Yanming Zhang, Lijun Jiang, Hsi Tseng Chou Dec 2023

Data-Driven Scheme For Joint Estimation Of Direction-Of-Arrival And Frequency With Uniform Linear Array, Yanming Zhang, Lijun Jiang, Hsi Tseng Chou

Electrical and Computer Engineering Faculty Research & Creative Works

This article presents a two-step dynamic mode decomposition (TSDMD) approach to estimate the direction of arrival (DOA) and frequency for multiple narrow-band sources with single uniform linear array (ULA). The proposed algorithm first decomposes the receiving spatial-temporal data into temporal dynamic modes and corresponding spatial spectrum that yields the DOA information. Then the decomposed temporal dynamic modes are analyzed via the augmented DMD to retrieve the frequency information. The estimated DOAs and frequencies are automatically paired without the extra computational cost with such a temporal-spectral correlated decomposition scheme. Also, the obtained spatial spectrum distribution implies the actual number of the …


Electromagnetic-Thermal Co-Design Of Base Station Antennas With All-Metal Ebg Structures, Huan Huan Zhang, Jun Bo Chao, Yi Wei Wang, Ying Liu, Yun Xue Xu, Heming Yao, Lijun Jiang, Xiang Hua Li Dec 2023

Electromagnetic-Thermal Co-Design Of Base Station Antennas With All-Metal Ebg Structures, Huan Huan Zhang, Jun Bo Chao, Yi Wei Wang, Ying Liu, Yun Xue Xu, Heming Yao, Lijun Jiang, Xiang Hua Li

Electrical and Computer Engineering Faculty Research & Creative Works

In order to improve the heat dissipation capability of the 5G base station, the electromagnetic and thermal performances of a base station antenna array are co-designed by adopting all-metal electromagnetic bandgap (EBG) structures. The geometrical dimension of the EBG structure is determined through balancing the electromagnetic and thermal performances of the antenna array. The operating frequency band (voltage standing wave ratio (VSWR) < 1.5) of the proposed antenna array can cover 3.4-3.8 GHz. Its realized gains, isolation, cross-polarized discrimination ratio, and half-power beamwidth are satisfactory compared with other state-of-the-art base station antennas. Most importantly, more than 9 C temperature reduction can be observed when comparing the heat dissipation capability of the proposed antenna array with the reference antenna array.


A Novel Renewable Energy Powered Zero Liquid Discharge Scheme For Ro Desalination Applications, Mamdouh A. Gadalla, Amr Abdel Fatah, Hany A. Elazab Dec 2023

A Novel Renewable Energy Powered Zero Liquid Discharge Scheme For Ro Desalination Applications, Mamdouh A. Gadalla, Amr Abdel Fatah, Hany A. Elazab

Chemical and Biochemical Engineering Faculty Research & Creative Works

This work proposes a conceptual model for a Zero Liquid Discharge (ZLD) for Reverse Osmosis (RO) desalination. The model describes a Process Flow Diagram (PFD). The proposed process relies on an RO followed by electrolyser, solar evaporator and mixing tank. The water reject from the RO is split into three fractions, one to an electrolyser to produce H2, another to solar evaporator to produce fresh water, third is remixed with water from the evaporator to reduce the salinity of the RO feed. The hydrogen produced in the electrolyser is burned and its energy is stored using cement blocks. The evaporator …


Evaluation Of Different Decontamination Procedures On Bond Strength To Sound And Caries Affected Dentin Using “No-Wait” Universal Adhesive, Lamiaa M. Moharam, Haidy N. Salem, Sherif Khadr, Ahmed Abdou Dec 2023

Evaluation Of Different Decontamination Procedures On Bond Strength To Sound And Caries Affected Dentin Using “No-Wait” Universal Adhesive, Lamiaa M. Moharam, Haidy N. Salem, Sherif Khadr, Ahmed Abdou

Chemical and Biochemical Engineering Faculty Research & Creative Works

Background: Current study aimed to evaluate the effect of different decontamination procedures on micro-shear bond strength (μSBS) of sound (SoD) and caries-affected dentin (CAD) of two universal adhesives after blood-saliva contamination. Methods: One hundred and eighty bovine anterior teeth were prepared and allocated into the respective groups according to tested dentin substrates [SoD, CAD], universal adhesives [Clearfil Bond Universal Quick (UBQ), All-Bond-Universal (ABU)], adhesive contamination stage [none, contamination before and after adhesives light-curing], and according to decontamination procedures [no decontamination, water rinsing, adhesive rebond, Ethylenediaminetetraacetic acid (ETDA) and chlorhexidine (CHX) application]. Universal adhesives were applied according to manufacturer instructions in …


Effects Of Simultaneous Co2 Addition To The Fuel And Oxidizer Streams On Soot Formation In Co-Flow Diffusion Ethylene Flame, Yu Yang, Shu Zheng, Yuzhen He, Hao Liu, Ran Sui, Qiang Lu Dec 2023

Effects Of Simultaneous Co2 Addition To The Fuel And Oxidizer Streams On Soot Formation In Co-Flow Diffusion Ethylene Flame, Yu Yang, Shu Zheng, Yuzhen He, Hao Liu, Ran Sui, Qiang Lu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Soot formation in a co-flow diffusion ethylene flame with the addition of CO2 to the fuel (the CO2-F), oxidizer (the CO2-O), and fuel/oxidizer (the CO2-F/O) streams was numerically and experimentally investigated in this study. The effects of different CO2 addition ways on soot inception, soot condensation, H-abstraction-C2H2-addition (HACA) and oxidation by O2/OH processes, were quantitatively analyzed by introducing the integrated reaction rates over the whole computational domain. The simulated and experimental results showed that the CO2-F/O was the most effective in inhibiting soot formation …


Experimental Study Of Surfactants’ Performance For Suppressing Coal Dust With Respirable Size, Zidong Zhao, Ping Chang, Guang Xu, Apurna Ghosh, Ramakrishna Morla Nov 2023

Experimental Study Of Surfactants’ Performance For Suppressing Coal Dust With Respirable Size, Zidong Zhao, Ping Chang, Guang Xu, Apurna Ghosh, Ramakrishna Morla

Mining Engineering Faculty Research & Creative Works

Long-term exposure to coal dust can lead to severe health problems in coal workers, including Coal Workers' Pneumoconiosis, making effective control of coal dust in underground mines essential. Water spraying is a widely used method for controlling coal dust, and adding surfactants can remarkably enhance its effectiveness. While previous studies have examined the influences of different coal particle sizes on surfactant performance, they have primarily focused on inhalable dust with sizes less than 100 µm. The impact of finer particle sizes, such as respirable dust with sizes less than 10 µm, remains inconclusive. This study aims to investigate the effects …


Modeling Hydration Kinetics Of Sustainable Cementitious Binders Using An Advanced Nucleation And Growth Approach, Taihao Han, Jie Huang, Gaurav Sant, Narayanan Neithalath, Ashutosh Goel, Aditya Kumar Nov 2023

Modeling Hydration Kinetics Of Sustainable Cementitious Binders Using An Advanced Nucleation And Growth Approach, Taihao Han, Jie Huang, Gaurav Sant, Narayanan Neithalath, Ashutosh Goel, Aditya Kumar

Electrical and Computer Engineering Faculty Research & Creative Works

Supplementary cementitious materials (SCMs) are utilized to partially substitute Portland cement (PC) in binders, reducing carbon-footprint and maintaining excellent performance. Nonetheless, predicting the hydration kinetics of [PC + SCM] binders is challenging for current analytical models due to the extensive diversity of chemical compositions and molecular structures present in both SCMs and PC. This study develops an advanced phase boundary nucleation and growth (pBNG) model to yield a priori predictions of hydration kinetics—i.e., time-resolved exothermic heat release profiles—of [PC + SCM] binders. The advanced pBNG model integrates artificial intelligence as an add-on, enabling it to accurately simulate hydration kinetics for …


New Dual Modality Technique Of Gamma-Ray Densitometry (Grd) And Optical Fiber Probe (Ofp) To Investigate Line-Averaged Diameter Profiles Of Gas, Liquid, And Solid Holdups Along The Height Of A Slurry Bubble Column, Omar Farid, Binbin Qi, Sebastián Uribe, Muthanna H. Al-Dahhan Nov 2023

New Dual Modality Technique Of Gamma-Ray Densitometry (Grd) And Optical Fiber Probe (Ofp) To Investigate Line-Averaged Diameter Profiles Of Gas, Liquid, And Solid Holdups Along The Height Of A Slurry Bubble Column, Omar Farid, Binbin Qi, Sebastián Uribe, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

A new hybrid measurement technique was developed and employed to study line-averaged three-phase holdup distribution in a Slurry Bubble Column Reactor (SBCR) using gamma-ray densitometry (GRD) and point optical fiber probe (OFP) techniques. The OFP technique was used to measure the local gas holdup at 45 nodes in the cross-section area of the SBCR at three different axial levels. Thus, the GRD technique measured the spectrum of the SBCR for two different orientations simultaneously with the OFP technique at the same operating conditions to determine the solid holdup distribution radially and axially. The line-averaged solid holdup for 25% solids loading …


Landscape Position And Cover Crops Affects Crop Yields In A Terrace-Tiled Field, Harpreet Kaur, Kelly A. Nelson, Gurbir Singh, Gurpreet Kaur, Katherine R. Grote Nov 2023

Landscape Position And Cover Crops Affects Crop Yields In A Terrace-Tiled Field, Harpreet Kaur, Kelly A. Nelson, Gurbir Singh, Gurpreet Kaur, Katherine R. Grote

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Cover Crops (CC) Provide Soil Ecosystem Benefits Including Reduced Soil Erosion, Improved Soil Health, and Nutrient Cycling. However, the Effect of CCs on Rotational Commodity Crop Grain Yields and Nutrient Uptake May Vary at Different Landscape Positions and under Different Soil Moisture Dynamics. the Objectives of This Study Were to Determine the Influence of CCs in a Terraced Field on Soil Moisture at Crop Emergence and Reproductive Stages of Corn (Zea Mays L) and Soybean (Glycine Max L. Merr.) Development, and Evaluate CCmix (Wheat (Triticum Aestivum L.), Radish (Raphanus Raphanistrum Subsp. Sativus), and Turnip (Brassica Rapa Subsp. Rapa)) and Cereal …


Cost Modelling For Dimension Stone Quarry Operations, M. A. Raza, S. Raza, M. U. Khan, M. Z. Emad, K. Jalil, S. A. Saki Nov 2023

Cost Modelling For Dimension Stone Quarry Operations, M. A. Raza, S. Raza, M. U. Khan, M. Z. Emad, K. Jalil, S. A. Saki

Mining Engineering Faculty Research & Creative Works

Dimension stone mining is Increasing because of growing demand from the building and construction industries. Diamond wire saw cutting is a popular dimension stone mining technique around the world. Estimation of the production cost for this method is critical for these operations. In this research a production cost model was developed for the mining of granite using a diamond wire saw. Cost and production data were collected from a granitic dolerite operation in Pakistan for a 4.5-year period and analyzed to identify the cost components. Fuel (34%), labor (15%), consumables (40%), and maintenance (5%) were found to be the four …


Evaluation Of Residual Flexural Behavior Of Corroded Fiber-Reinforced Super Workable Concrete Beams, Jingjie Wei, Nima Farzadnia, Alfred Addai-Nimoh, Kamal Khayat Nov 2023

Evaluation Of Residual Flexural Behavior Of Corroded Fiber-Reinforced Super Workable Concrete Beams, Jingjie Wei, Nima Farzadnia, Alfred Addai-Nimoh, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This Study Investigates the Effect of Macro Synthetic Fiber (MSF) Volume and Crack Widths on Corrosion of the Reinforcing Bars and Residual Flexural Behavior of Fiber-Reinforced Super-Workable Concrete (FR-SWC) Beams Exposed to Accelerated Corrosion. FR-SWC Beams Prepared with 0, 0.33%, and 0.66% MSF Were Pre-Cracked at 0.2-, 0.4-, and 0.75-Mm Widths Before Corrosion Testing. the Controlled Crack Width Was Initiated in One Set of Beams that Were Then Unloaded. the Crack Width Was Maintained for Another Set of Beams during Corrosion Testing by Inserting a Shim. Test Results Showed that the Use of 0.33% and 0.66% MSF Reduced Crack Development …


Cement-Based Materials With Solid-Gel Phase Change Materials For Improving Energy Efficiency Of Building Envelope, Zhuo Liu, Jiang Du, Ryan Steere, Joshua P. Schlegel, Kamal Khayat, Weina Meng Nov 2023

Cement-Based Materials With Solid-Gel Phase Change Materials For Improving Energy Efficiency Of Building Envelope, Zhuo Liu, Jiang Du, Ryan Steere, Joshua P. Schlegel, Kamal Khayat, Weina Meng

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

This paper evaluated the cement-based materials incorporated with novel solid-gel phase change materials (PCMs) for improving the energy efficiency of building envelopes. This novel PCM is form-stable, which will not leak as solid-liquid PCMs do and not need encapsulation, and it features high energy-storage capacity. Experimental results showed that the thermal properties of cement-based materials were improved as the increase of PCM content. A 30% replacement of sand by volume with PCM can increase the latent heat of the mixture from around 0 to 7 J/g and decrease the thermal conductivity of PCM mortar based on the generalized self-consistent (GSC) …


Boosting Snr Of Cascaded Fbgs In A Sapphire Fiber Through A Rapid Heat Treatment, Farhan Mumtaz, Hanok Tekle, Bohong Zhang, Jeffrey D. Smith, Ronald J. O'Malley, Rex E. Gerald, Jie Huang Nov 2023

Boosting Snr Of Cascaded Fbgs In A Sapphire Fiber Through A Rapid Heat Treatment, Farhan Mumtaz, Hanok Tekle, Bohong Zhang, Jeffrey D. Smith, Ronald J. O'Malley, Rex E. Gerald, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This Letter reports the performance of femtosecond (fs) laser-written distributed fiber Bragg gratings (FBGs) under high-temperature conditions up to 1600°C and explores the impact of rapid heat treatment on signal-to-noise ratio (SNR) enhancement. FBGs are essential for reliable optical sensing in extreme temperature environments. Comprehensive tests demonstrate the remarkable performance and resilience of FBGs at temperatures up to 1600°C, confirming their suitability for deployment in such conditions. The study also reveals significant fringe visibility improvements of up to ∼10 dB on a 1-m-long sapphire optical fiber through rapid heat treatment, representing a first-time achievement to the best of our knowledge. …


Iron Oxide Ore Mineralogy And Its Plant Flotation Circuits Nodal Analysis Simulation And Comparison, Ying Hou, Ahmed Sobhy, Samah Abdel Aziz Nov 2023

Iron Oxide Ore Mineralogy And Its Plant Flotation Circuits Nodal Analysis Simulation And Comparison, Ying Hou, Ahmed Sobhy, Samah Abdel Aziz

Mining Engineering Faculty Research & Creative Works

Mining operations usually provide ore of varying characteristics. At the Donganshan Sintering Plant, the ore is a low-grade, complex, hard-to-separate carbonate containing iron ore, and a two-step flotation circuit was previously developed to overcome the negative impact of the carbonates on the reverse flotation process. However, with the further expansion in the mining operations, it was difficult to maintain a highly efficient flotation process. Thus, the mineral liberation analyzer (MLA) was utilized to conduct an in-depth process mineralogy investigation. MLA showed that the main useful minerals in this ore are magnetite/hematite of 45% total iron, and the main gangue mineral …


Effect Of Type And Quantity Of Inherent Alkali Cations On Alkali-Silica Reaction, Pengfei Ma, Jiaoli Li, Jincheng Bai, Ying Zhuo, Lingyu Chi, Yanping Zhu, Zhenhua Shi, Hongyan Ma, Genda Chen Nov 2023

Effect Of Type And Quantity Of Inherent Alkali Cations On Alkali-Silica Reaction, Pengfei Ma, Jiaoli Li, Jincheng Bai, Ying Zhuo, Lingyu Chi, Yanping Zhu, Zhenhua Shi, Hongyan Ma, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, the macroscopical expansion induced by alkali-silica reaction (ASR) and its corresponding ASR products are investigated using ordinary Portland cement (OPC) mortar specimens with a gradient of boosted alkalis. Experimental results show that the expansion increases with the concentration of inherent alkalis. Sodium-boosted samples expand approximately three times as much as potassium-boosted samples. ASR gels that are present in aggregate veins are calcium-free and amorphous; the atomic ratios of ASR gels are nearly independent of the type and quantity of alkali cations. Aggregate ASR gel exudation occurs in high (≥2.5 %) sodium cases and produces potential Na-shlykovite. Crystalline …


Implementation Of Experimental Static Recrystallization Of High Strength Steel Into Computational Simulation Of Multi-Pass Slab Hot Rolling, S. K. Dasari, S. Ganguly, A. Abutunis, K. Chandrashekhara, M. F. Buchely, S. N. Lekakh, R. J. O'Malley, T. Natarajan Nov 2023

Implementation Of Experimental Static Recrystallization Of High Strength Steel Into Computational Simulation Of Multi-Pass Slab Hot Rolling, S. K. Dasari, S. Ganguly, A. Abutunis, K. Chandrashekhara, M. F. Buchely, S. N. Lekakh, R. J. O'Malley, T. Natarajan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Microstructural changes and softening due to static recrystallization have a critical influence on thermo-mechanical behavior of high strength steels during industrial multi-pass hot rolling. Numerical simulation using finite element analysis (FEA) can be used to accurately predict the softening behavior during the hot rolling process. Therefore, the implementation of an experimentally defined static recrystallization model into FEA is necessary to get realistic simulation prediction. in this study, the extent of softening during static recrystallization in Si and Mn alloyed high strength steel was measured using double hit tests. a Gleeble™ thermo-mechanical simulator was used to perform the double hit tests …


Comparison Of The Thermal Stability In Equal-Channel-Angular-Pressed And High-Pressure-Torsion-Processed Fe–21cr–5al Alloy, Maalavan Arivu, Andrew Hoffman, Jiaqi Duan, Jonathan Poplawsky, Xinchang Zhang, Frank Liou, Rinat Islamgaliev, Ruslan Valiev, Haiming Wen Nov 2023

Comparison Of The Thermal Stability In Equal-Channel-Angular-Pressed And High-Pressure-Torsion-Processed Fe–21cr–5al Alloy, Maalavan Arivu, Andrew Hoffman, Jiaqi Duan, Jonathan Poplawsky, Xinchang Zhang, Frank Liou, Rinat Islamgaliev, Ruslan Valiev, Haiming Wen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Nanostructured steels are expected to have enhanced irradiation tolerance and improved strength. However, they suffer from poor microstructural stability at elevated temperatures. in this study, Fe–21Cr–5Al–0.026C (wt.%) Kanthal D (KD) alloy belonging to a class of (FeCrAl) alloys considered for accident-tolerant fuel cladding in light-water reactors is nanostructured using two severe plastic deformation techniques of equal-channel angular pressing (ECAP) and high-pressure torsion (HPT), and their thermal stability between 500–700 °C is studied and compared. ECAP KD is found to be thermally stable up to 500 °C, whereas HPT KD is unstable at 500 °C. Microstructural characterization reveals that ECAP KD …


Design Of Impact-Free Gaits For Planar Bipeds And Their Stabilization Using Impulsive Control, Aakash Khandelwal, Nilay Kant, Ranjan Mukherjee Nov 2023

Design Of Impact-Free Gaits For Planar Bipeds And Their Stabilization Using Impulsive Control, Aakash Khandelwal, Nilay Kant, Ranjan Mukherjee

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The problem of designing and stabilizing impact-free gaits is considered for point-foot planar bipeds. A set of geometric constraints, which eliminate impact forces at the time of leg interchange, are used to design the gaits. A family of gaits, where the stride length and walking speed can be chosen independently for each gait, is guaranteed to exist. A continuous controller is used to enforce the constraints associated with a desired gait and intermittent impulsive inputs are applied to stabilize the gait. A five-link biped example is used to illustrate the procedure for designing impact-free gaits. The effectiveness of the continuous …


Advancing Airport Project Delivery: A Comparison Of Design-Build And Traditional Methods In Terms Of Schedule And Cost Performance, Ramy Khalef, Islam H. El-Adaway Nov 2023

Advancing Airport Project Delivery: A Comparison Of Design-Build And Traditional Methods In Terms Of Schedule And Cost Performance, Ramy Khalef, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Current airport infrastructure is in a state of decline, with reports scoring it at an underperforming classification of D+. To address this issue, significant improvement and advancement of the infrastructure is needed. With backing on an authoritative level, the nation can expect an increase in the number of improvement projects. Airport stakeholders have long been accustomed to delivering their projects using traditional methods, such as design-bid-build (DBB). Design-build (DB) is an alternative delivery method that has added benefits for project metrics, such as schedule and cost performance. There is a lack of research evaluating DB within the context of airport …


Vacancy Ordering In Zirconium Carbide With Different Carbon Contents, Yue Zhou, Jeremy Lee Watts, Cheng Li, William Fahrenholtz, Gregory E. Hilmas Nov 2023

Vacancy Ordering In Zirconium Carbide With Different Carbon Contents, Yue Zhou, Jeremy Lee Watts, Cheng Li, William Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

Zirconium carbide (ZrCx) ceramics with different carbon contents were prepared by reactive hot-pressing. The rock-salt structure of ZrCx was the only phase detected by x-ray diffraction of the hot pressed ceramics. The relative densities of ZrCx decreased as carbon content increased, in general. The actual carbon contents were measured by completely oxidizing the ZrCx ceramics to ZrO2. For most compositions, the actual carbon contents were higher than nominal batched compositions, presumably due to carbon uptake from the graphite furnace and hot press dies. Selected area electron diffraction and neutron powder diffraction revealed the presence of carbon vacancy ordering …


Searching For Unknown Material Properties For Am Simulations, Aaron Flood, Rachel Boillat, Sriram Praneeth Isanaka, Frank W. Liou Nov 2023

Searching For Unknown Material Properties For Am Simulations, Aaron Flood, Rachel Boillat, Sriram Praneeth Isanaka, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Additive manufacturing (AM) simulations are effective for materials that are well characterized and published; however, for newer or proprietary materials, they cannot provide accurate results due to the lack of knowledge of the material properties. This work demonstrates the process of the application of mathematical search algorithms to develop an optimized material dataset which results in accurate simulations for the laser directed energy deposition (DED) process. This was performed by first using a well-characterized material, Ti-64, to show the error in the predicted melt pool was accurate, and the error was found to be less than two resolution steps. Then, …