Key Technology For Incremental Launching Construction Of Double Guide Beam Of Steel Box Girder,
2024
CCCC Second Harbor Engineering Co .,Ltd., Wuhan ,Hubei 430012 , China
Key Technology For Incremental Launching Construction Of Double Guide Beam Of Steel Box Girder, Sun Xiaoqiang, Yue Xinxing
Journal of China & Foreign Highway
By taking the incremental launching construction of the steel box girder at the 6th hole of the approach bridge of Baoji Taigu Bridge as the engineering background，the original plan adopted single-guide beam multi-point walking incremental launching technology for assembly and incremental launching on the prestressed reinforced concrete beam of the adjacent hole.Since the middle span of the concrete beam cannot withstand the concentrated force at the incremental launching points，the multi-guide beam multi-point walking incremental launching technology was finally used to arrange the incremental launching points at the transverse diaphragm plate of the end of the concrete beam.By increasing the incremental …
Emergency Vehicle Dispatching Model Considering Demand Urgency And Delivery Fairness,
2024
Hunan Key Laboratory of Smart Roadway and Cooperative Vehicle-Infrastructure Systems , Changsha University of Science & Technology , Changsha ， Hunan 410114 , China
Emergency Vehicle Dispatching Model Considering Demand Urgency And Delivery Fairness, Long Kejun, Liu Jia, Gao Zhibo, Chen Suqian, Zhang Zhonggen
Journal of China & Foreign Highway
In emergency vehicle dispatching after unexpected events，it is crucial to prioritize critical nodes with high demand urgency while minimizing excessive delivery delays at other nodes to prevent secondary impacts.On this basis，this study developed an emergency vehicle dispatching model that considered demand urgency and delivery delay fairness.Firstly，the entropy weight-TOPSIS method was used to calculate the demand urgency for each node，and a delivery delay balance index was introduced to minimize disparities in delivery delays between nodes.Secondly，a multi-objective optimization model was established with total delivery time，overall cost，and delivery delay balance as objectives，while considering constraints such as inventory levels at distribution centers and route …
Working Properties Of Steel Tube Batter Piles With Concrete Infill Based On Abaqus,
2024
School of Civil Engineering , Changsha University of Science & Technology , Changsha , Hunan 410114 , China
Working Properties Of Steel Tube Batter Piles With Concrete Infill Based On Abaqus, Yang Meiliang, Li Liemin, Sun Kunjiang, Han Rui, Zhong Yang
Journal of China & Foreign Highway
In order to explore the respons e characteristics of steel tube batter piles with concrete infill under vertical load，the steel tube batter pile with concrete infill used in Saribas Bridge in Malaysia was taken as the research object.Based on the numerical simulation method，the frictional resistance of the inner and outer walls of the steel tube，the frictional resistance around the pile at the section，and the bending moment bearing ratio between the steel tube and the concrete core of this type of batter pile under vertical load were studied.The results show that the passive-side frictional resistance of the 0–15 m pile section …
Synthesis Of Activated Carbon From Coconut Shell And Recycled Styrofoam Nanofiber For Water Filtration,
2024
Master of Physics Education, Universitas Sriwijaya, Universitas Sriwijaya, Indralaya 30862, Indonesia.
Synthesis Of Activated Carbon From Coconut Shell And Recycled Styrofoam Nanofiber For Water Filtration, Rahma Dani, Ismet Ismet, Leni Marlina, Rona Alisya, Muhamad Abel Kirana Aldi, Anggi Ludiansyah, Lintang Auliya Kurdiati, Meutia Kamilatun Nuha Ap Idjan, Agung Mataram, Muhammad Rama Almafie, Ida Sriyanti
Makara Journal of Science
Water pollution affects life sustainability; hence, several efforts have been exerted to overcome this problem. For ex-ample, nanofiber membrane technology is introduced to retain solutes while allowing only water molecules to pass through the system. Therefore, this study aimed to maximize the technology for water filtration using the electrospin-ning method by combining Styrofoam waste-based polymer with activated carbon from coconut shell waste (ACCS). The nanofiber diameter produced ranged from 590 nm to 610 nm with porous characteristics and without beads. The carbon content varied from 68.04% to 69.84%, according to the energy dispersive X-ray measurement, demonstrating the composite’s effectiveness. The …
A Mechanistic Study Of Silicon Nanocrystal Formation Via Solid State Synthesis,
2024
Portland State University
A Mechanistic Study Of Silicon Nanocrystal Formation Via Solid State Synthesis, Katherine Mccarthy Weinfurter
Dissertations and Theses
Silicon nanocrystals (SiNCs) show promising physiochemical properties that could be used in industrial applications. The production of SiNCs through solid-state synthesis is ideal due to relatively low cost of equipment and chemical reagents, as well as the ability to scale-up production. A widely known and commonly used precursor previously used in solid-state synthesis for SiNCs, hydrogen silsesquioxane (HSiO1.5), was discontinued in chemical manufacturing, which has led to researching alternative precursors (or starting materials). We have identified that there is a gap of knowledge related to producing these precursors, as well as the mechanistic understanding of the chemical reactions …
Zeolite 13x Particles With Porous Tio2 Coating And Ag2o Nanoparticles As Multi-Functional Filler Materials For Face Masks,
2024
Missouri University of Science and Technology
Zeolite 13x Particles With Porous Tio2 Coating And Ag2o Nanoparticles As Multi-Functional Filler Materials For Face Masks, Wei Su, Kaiying Wang, Han Yu, Fateme Fayyazbakhsh, Jeremy Watts, Yue-Wern Huang, Jee-Ching Wang, Xinhua Liang
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Adsorbent components in face masks are crucial for protecting individuals exposed to dangerous situations. In this study, one porous TiO2 layer was deposited on zeolite 13X particles by coating hybrid organic/inorganic titanium alkoxide film via molecular layer deposition (MLD), followed by heat treatment to remove organic components in the MLD film. Various concentrations of Ag2O nanoparticles were impregnated on the TiO2-coated 13X particles, offering a wide range of antibacterial, antifungal, and antiviral characteristics. The obtained composite particles were characterized using X-ray photoelectron spectroscopy and thermal gravimetric analysis to study the composition and mass loading of …
Surface Chemistry And Adsorption Mechanism Of Orfom® D8 For Cu Depression In Cu-Mo Flotation,
2024
Montana Technological University
Surface Chemistry And Adsorption Mechanism Of Orfom® D8 For Cu Depression In Cu-Mo Flotation, Patrick Jeff Mensah
Graduate Theses & Non-Theses
In traditional chalcopyrite-molybdenite (Cu-Mo) flotation separation systems, inorganic depressants such as NaSH and NaCN are used to selectively depress chalcopyrite making it more hydrophilic so molybdenite can be floated and recovered. NaSH and NaCN are highly toxic, have high explosion potential, strong odor, and readily oxidize in air resulting in a high consumption rates. To control oxidation, nitrogen gas, and Nokes reagent are both necessary, making the process even more expensive. In addressing these challenges, attention is fast shifting to disodium carboxymethyl trithiocarbonate (Orfom® D8), a novel organic depressant designed to replace conventional inorganic depressants because it does not easily …
Lignin Cationization For The Removal Of Phosphates And Nitrates From Effluents Of Wastewater Treatment Plants,
2024
Louisiana State University and Agricultural and Mechanical College
Lignin Cationization For The Removal Of Phosphates And Nitrates From Effluents Of Wastewater Treatment Plants, Fannyuy V. Kewir
LSU Master's Theses
The removal of phosphates and nitrates from wastewater treatment plant (WWTP) effluents is important for preventing pollution of receiving waters. In this study, we chemically modified alkaline lignin (aLN) with quaternary ammonium groups to obtain biodegradable cationic lignin (cLN). We characterized the cLN and tested its efficacy for removing phosphates and nitrates in a lab setting and on field-collected WWTP samples. Adsorption isotherm and kinetic studies were performed in aqueous media, and the effects of several variables (contact time, pH, initial concentration, and adsorbent dose) were investigated. The Langmuir isotherm described phosphate and nitrate adsorption well, with R2 values of …
Ge/Sige Quantum Wells: Material For The Post-Moore Era,
2024
University of New Mexico - Main Campus
Ge/Sige Quantum Wells: Material For The Post-Moore Era, Troy Alexander Hutchins-Delgado
Optical Science and Engineering ETDs
This dissertation demonstrates high-quality germanium quantum wells on a 200 mm silicon wafer platform, enabling novel device possibilities. Partnering with a commercial silicon-germanium epitaxy supplier, we obtained shallow, undoped germanium quantum wells with high-crystalline quality, confirmed through x-ray diffraction, secondary ion mass spectroscopy, high-resolution scanning transmission electron microscopy, and energy dispersive x-ray spectroscopy. Hall bar devices fabricated on single quantum wells revealed that surface preparation can tune transport properties while maintaining peak mobilities around 105 cm2V−1s−1. Manganese-germanide spintronic contacts were integrated via solid-state reaction, with contact quality assessed through Schottky diodes, transfer length …
Nature-Derived Flame Retardant For Cotton Fabrics With Green Coconut Shells,
2024
University of Georgia
Nature-Derived Flame Retardant For Cotton Fabrics With Green Coconut Shells, Tarikul Islam, Abdullah Al Rakib Shikder, Md Shahabul Hossen, Md Mazbah Uddin, Md Tanvir Hossain, M. Mahbubul Bashar
Michigan Tech Publications
This study presents an eco-friendly flame-retardant solution for cellulosic fabrics using green coconut shell (GCS) extract and phytic acid (PA). Cellulosic materials are highly flammable and release harmful gases during combustion. Conventional flame retardants may pose environmental and health risks while impacting the fabric quality. GCS extract is a rich source of tannins, phosphorus, silicates, metallic salts, and oxides and is explored as a novel flame retardant (FR) for cotton fabrics. Cotton samples were pretreated with PA and then with varying concentrations of GCS extract using a padding technique. Comprehensive characterization followed, including limiting oxygen index (LOI), thermogravimetric analysis (TGA), …
Using Additive Manufacturing To Characterize Effects Of Sparse Infill Density And Sparse Infill Pattern On The Compressive Properties Of Short Strand Carbon Fiber Infused Petg,
2024
Mississippi State University
Using Additive Manufacturing To Characterize Effects Of Sparse Infill Density And Sparse Infill Pattern On The Compressive Properties Of Short Strand Carbon Fiber Infused Petg, Luke C. Salisbury
Honors Theses
The advent of additive manufacturing has revolutionized the prototyping, design, and manufacturing of new and innovative products. Through the use of Fused Deposition Modeling (FDM), parts can be manufactured using different sparse infill percentages (the percentage of void space within a printed object) and sparse infill patterns (the lattice structure of material within the object). Through the manipulation of these variables, the same material and part can have different compressive and flexural properties. In addition to sparse infill, the thermoplastics used in fused deposition modeling can be reinforced with carbon fiber strands to create a printable composite material capable of …
Complex Precipitation Behavior In A Co-Free High Entropy Alloy During Aging,
2024
Missouri University of Science and Technology
Complex Precipitation Behavior In A Co-Free High Entropy Alloy During Aging, Matthew Luebbe, Fan Zhang, Jonathan D. Poplawsky, Jiaqi Duan, Haiming Wen
Materials Science and Engineering Faculty Research & Creative Works
High entropy alloys (HEAs) demonstrate high strength, thermal stability, and irradiation resistance, making them desirable for applications in nuclear reactors and other harsh environments. Many existing HEAs contain cobalt (Co), which makes them unsuitable for nuclear applications due to the long-term activation of Co. A previously studied Co-free alloy, (Fe0.3Ni0.3Mn0.3Cr0.1)88Ti4Al8, exhibits high strength but compromised ductility due to its network of brittle precipitates upon aging. This work investigates the formation mechanism and evolution of the precipitates, including L12 (Ni3Ti type, ordered face-centered cubic …
Multiphysics Modeling And Experimental Validation Of High-Strength Steel In Laser Powder Bed Fusion Process,
2024
Missouri University of Science and Technology
Multiphysics Modeling And Experimental Validation Of High-Strength Steel In Laser Powder Bed Fusion Process, M. Rangapuram, S. Babalola, J. W. Newkirk, L. N. Bartlett, F. W. Liou, K. Chandrashekhara, Stephen R. Cluff
Materials Science and Engineering Faculty Research & Creative Works
Laser powder bed fusion (LPBF) is a subset of the additive manufacturing process in which a laser beam selectively joins the metal powder into a desired part in a sequential layer process. Owing to its complex nature of rapid heating and cooling of the melt pool, there is a need to understand the melt pool behavior and its effects on the final manufactured part. a densely packed powder bed is highly desirable for fabricating a superior part using the LPBF process. in this work, discrete element model was used to generate powder beds with realistic powder properties and various factors …
Striking A Balance: Market Shock & Responses In Automotive Components Manufacturing,
2024
Clemson University
Striking A Balance: Market Shock & Responses In Automotive Components Manufacturing, Emma Lane Mcgahey
All Theses
This thesis examines the effects of extreme market shocks on supply chain dynamics within the automotive industry. Through an analysis of demand data from an automotive manufacturer to its component suppliers (January 2018 to May 2024), the study investigates the relationship between market shocks and supply chain responses, providing insights into how auto components inventory management handles downstream responses to market shocks. With supporting public data—from FRED, BLS, and the U.S. Census Bureau resources—we explore two primary relationships: the impact of market shocks on the Average Standard Deviation of Demand (SDO) and the effect of demand variability on expedited pricing …
Estimating The Possible Qpos Of M87* From The Parameters Of A Hairy Kerr Black Hole,
2024
Missouri University of Science and Technology
Estimating The Possible Qpos Of M87* From The Parameters Of A Hairy Kerr Black Hole, Orhan Donmez, Fatih Dogan
Materials Science and Engineering Faculty Research & Creative Works
In this paper, we study the dynamics of the shock cone formed around a hairy Kerr black hole due to Bondi– Hoyle–Lyttleton (BHL) accretion and investigate the quasi-periodic oscillations (QPO) behaviors resulting from the black hole-cone interaction, aiming to predict the QPO frequencies that may occur around the M87∗ black hole. To achieve this, we use the hairy Kerr black hole parameters consistent with the observed shadow parameters of M87∗ as initial conditions in numerical simulations, revealing the structure of the resulting shock cone and QPOs in a strong gravitational field. Numerical calculations show that the deviation of …
Hafnium Oxide Coating To Improve The Oxidation Behavior Of Zirconium Diboride,
2024
Missouri University of Science and Technology
Hafnium Oxide Coating To Improve The Oxidation Behavior Of Zirconium Diboride, Jan E. Förster, William G. Fahrenholtz, Gregory E. Hilmas, Ravisankar Naraparaju
Materials Science and Engineering Faculty Research & Creative Works
Hafnium dioxide (HfO2) coatings were successfully deposited on zirconium diboride (ZrB2) using reactive magnetron sputtering. After the oxidation at 1500°C or 1600°C, the mutual dissolution of HfO2 and thermally grown ZrO2 was observed which has resulted in the formation of a mixed oxide zone. As the enrichment of the mixed oxide zone by ZrO2 progresses, monoclinic/tetragonal phase transition temperature of ∼1790°C for nominally pure HfO2 moves towards ∼1500 °C. Finally, the inevitable phase transition from monoclinic to tetragonal structure results in the development of cracks, pores, and gaps within the mixed oxide …
Machine Learned Interatomic Potentials For Ternary Carbides Trained On The Aflow Database,
2024
Missouri University of Science and Technology
Machine Learned Interatomic Potentials For Ternary Carbides Trained On The Aflow Database, Josiah Roberts, Biswas Rijal, Simon Divilov, Jon Paul Maria, William G. Fahrenholtz, Douglas E. Wolfe, Donald W. Brenner, Stefano Curtarolo, Eva Zurek
Materials Science and Engineering Faculty Research & Creative Works
Large-density functional theory (DFT) databases are a treasure trove of energies, forces, and stresses that can be used to train machine-learned interatomic potentials for atomistic modeling. Herein, we employ structural relaxations from the AFLOW database to train moment tensor potentials (MTPs) for four carbide systems: CHfTa, CHfZr, CMoW, and CTaTi. The resulting MTPs are used to relax ~6300 random symmetric structures and are subsequently improved via active learning to generate robust potentials (RP) that can relax a wide variety of structures, and accurate potentials (AP) designed for the relaxation of low-energy systems. This protocol is shown to yield convex hulls …
Toward Electrochemical Detection Of Salmonella Enterica Serovar Enteritidis On Hydroponically Grown Green Onions (Allium Fistulosum L.),
2024
Clemson University
Toward Electrochemical Detection Of Salmonella Enterica Serovar Enteritidis On Hydroponically Grown Green Onions (Allium Fistulosum L.), Lisseth Casso-Hartmann
All Theses
The Food and Drug Administration (FDA) established standards during the growing, harvesting, packing, and holding of produce for human consumption as part of implementing the Food Safety Modernization Act (FSMA). One of the main requirements for farmers is to detect environmental pathogens such as Salmonella enterica species in water and sprout samples. S. enterica is a bacterium of significant concern due to its pathogenicity and ability to survive and persist in diverse environmental conditions. S. enterica has been associated with recalls in ready-to-eat foods. Traditional detection methods include Enzyme-Linked Immunosorbent Assay (ELISA), Polymerase Chain Reaction (PCR), and plate counting, which …
Modeling, Synthesis, And Experimental Characterization Of Rhenium Disulfide For Optoelectronic Devices,
2024
University of Arkansas, Fayetteville
Modeling, Synthesis, And Experimental Characterization Of Rhenium Disulfide For Optoelectronic Devices, Solomon Opeyami Ojo
Graduate Theses and Dissertations
Two-dimensional (2D) transition metal dichalcogenides (TMDs) have garnered considerable interest for their potential in optoelectronics and photonics owing to their remarkable combination of electronic, optical, and mechanical properties. These characteristics distinguish them from other 2D materials, including graphene, making them particularly valuable for next-generation technologies. This dissertation focuses on ReS₂, a 2D TMD with a unique anisotropic 1T distorted crystal structure. The research aims to elucidate its fundamental properties through a combination of theoretical modeling, material synthesis, and experimental characterization techniques, with the goal of optimizing ReS₂ for device applications. A theoretical investigation utilizing Density Functional Theory …
Ellipticity-Controlled Exceptional Points From Nanoscale Metasurfaces,
2024
Washington University in St. Louis
Ellipticity-Controlled Exceptional Points From Nanoscale Metasurfaces, Benjamin Goldberg
McKelvey School of Engineering Graduate Student Theses & Dissertations
Precise control over light polarization is critical for advancing technologies in telecommunica- tions, quantum computing, and image sensing. However, existing methods for manipulating polarization around exceptional points in non-Hermitian systems, have exclusively focused on circular polarization and work with reflected light. To address this limitation, we de- velop a novel metasurface platform with high-Q resonators that enables tunable control of polarization exceptional points across arbitrary ellipticity for transmitted light. Our design uses orthogonally polarized guided mode resonators in a two-layer silicon metasurface, where careful tuning of the dipolar guided mode resonances (DGMRs) and layer spacing allows us to control the …
