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Tibial Strains And Tray-Bone Micromotions After Total Knee Arthroplasty: Computational Studies Evaluating The Tibial Fixation, Huizhou Yang Jan 2021

Tibial Strains And Tray-Bone Micromotions After Total Knee Arthroplasty: Computational Studies Evaluating The Tibial Fixation, Huizhou Yang

Electronic Theses and Dissertations

Cemented and cementless fixation in total knee arthroplasty (TKA) have been successfully used for decades. As the number of younger and more active patients treated with TKA continues to increase, long-term implant survivorship is of increasing importance. One of the most common complications and hence the reason for revision is mechanical loosening (23.1% of all revised TKA). The loosening mechanisms have been proposed for different fixation types. For cemented fixation, bone remodeling after surgery is regulated by the changes in strain energy density (SED). The recruitment of osteoclasts and osteoblasts is controlled by SED-related signals. Insufficient stimuli can promote bone …


In Situ Characterization Of Municipal Solid Waste Using Membrane Interface Probe (Mip) And Hydraulic Profiling Tool (Hpt) In An Active And Closed Landfill, M. Sina Mousavi, Yuan Feng, Josh Mccann, Jongwan Eun Jan 2021

In Situ Characterization Of Municipal Solid Waste Using Membrane Interface Probe (Mip) And Hydraulic Profiling Tool (Hpt) In An Active And Closed Landfill, M. Sina Mousavi, Yuan Feng, Josh Mccann, Jongwan Eun

Department of Civil and Environmental Engineering: Faculty Publications

Municipal solid waste (MSW) landfills near a metropolitan area are renewable energy resources to produce heat and methane that can generate electricity. However, it is difficult to use those sources productively because disposed MSW in landfills are spatially and temporally heterogeneous. Regarding the prediction of the sources, the analysis of in situ MSW properties is an alternative way to reduce the uncertainty and to understand complex processes undergoing in the landfill effectively. A hydraulic profiling tool (HPT) and membrane interface probe (MIP) test measures the continuous profile of MSW properties with depth, including hydraulic pressure, temperature, electrical conductivity (EC), and …


A Hybrid Biological-Adsorption Approach For The Treatment Of Contaminated Groundwater Using Immobilized Nanoclay-Algae Mixtures, Sara Mollamohammada, Ashraf Aly Hassan, Mohamed Dahab, Sandeep Kumar Jan 2021

A Hybrid Biological-Adsorption Approach For The Treatment Of Contaminated Groundwater Using Immobilized Nanoclay-Algae Mixtures, Sara Mollamohammada, Ashraf Aly Hassan, Mohamed Dahab, Sandeep Kumar

Department of Civil and Environmental Engineering: Faculty Publications

Mixing the Scenedesmus species with nanoclay and immobilizing in sodium was evaluated as a sustainable treatment method for removing nitrate, atrazine, and metals from groundwater. Gel beads containing the hybrid mixture removed 100% of 10 mg/L N nitrate and 98% of 100 μg/L atrazine from synthetic groundwater in three days. The optimal amount of nanoclay was found to be 0.30 mg per bead. The experimental data fit well into a Freundlich adsorption iso- therm and followed pseudo first-order kinetics. When tested in actual groundwater, 91% of nitrate and 100% of Cr, Se, and V were eliminated in three days without …


Natural Hazards Perspectives On Integrated, Coordinated, Open, Networked (Icon) Science, Sanjib Sharma, Kshitij Dahal, Lorenzo Nava, Manish Raj Gouli, Rocky Talchabhadel, Jeeban Panthi, Tirthankar Roy, Ganesh R. Ghimire Jan 2021

Natural Hazards Perspectives On Integrated, Coordinated, Open, Networked (Icon) Science, Sanjib Sharma, Kshitij Dahal, Lorenzo Nava, Manish Raj Gouli, Rocky Talchabhadel, Jeeban Panthi, Tirthankar Roy, Ganesh R. Ghimire

Department of Civil and Environmental Engineering: Faculty Publications

This article is about the state of ICON principles Goldman et al. (2021), https://doi. org/10.1029/2021EO153180 in natural hazards and a discussion on the opportunities and challenges of adopting them. Natural hazards pose risks to society, infrastructure, and the environment. Hazard interactions and their cascading phenomena in space and time can further intensify the impacts. Natural hazards’ risks are expected to increase in the future due to environmental, demographic, and socioeconomic changes. It is important to quantify and effectively communicate risks to inform the design and implementation of risk mitigation and adaptation strategies. Multihazard multisector risk management poses several nontrivial challenges, …


Pectin Modified Metal Nanoparticles And Their Application In Property Modification Of Biosensors, Meena Nemiwal, Tian C. Zhang, Dinesh Kumar Jan 2021

Pectin Modified Metal Nanoparticles And Their Application In Property Modification Of Biosensors, Meena Nemiwal, Tian C. Zhang, Dinesh Kumar

Department of Civil and Environmental Engineering: Faculty Publications

Pectin is a structural anionic heteropolysaccharide and abundantly found in the cell wall of terrestrial trees and plants. It exhibits several advantageous properties such as non-toxicity, cheap, biodegradable, biocompatible, abundant, flexible, etc. Functional groups like carboxylic acid and hydroxyl make pectin suitable to be covalently bonded with other biomolecules and proteins. Based on these properties, pectin is being extensively employed to encapsulate/coat metal nanoparticles (MNPs) to inhibit their aggregation and enhancing the suitability of MNPs for a wide range of applications in healthcare like drug delivery, antimicrobial activity, antioxidant etc. Another important application of pectin is to enhance the electrochemical …


Combining Electrochemical Nitrate Reduction And Anammox For Treatment Of Nitrate-Rich Wastewater: A Short Review, Xinyi Zou, Chongjun Chen, Changhong Wang, Qun Zhang, Zhuowei Yu, Haiping Wu, Chao Zhuo, Tian C. Zhang Jan 2021

Combining Electrochemical Nitrate Reduction And Anammox For Treatment Of Nitrate-Rich Wastewater: A Short Review, Xinyi Zou, Chongjun Chen, Changhong Wang, Qun Zhang, Zhuowei Yu, Haiping Wu, Chao Zhuo, Tian C. Zhang

Department of Civil and Environmental Engineering: Faculty Publications

Treatment of nitrate-rich wastewater is important but challenging for the conventional biological denitrification process. Here, we propose combining the electrochemical reduction and anaerobic ammonium oxidation (anammox) processes together for treatment of nitrate-rich wastewater. This article reviews the mechanism and current research status of electrochemical reduction of nitrate to ammonium as well as the mechanism and applicability of the anammox process. This article discusses the principles, superiorities, and challenges of this combined process. The feasibility of the combined process depends on the efficiency of electrochemical nitrate reduction to ammonium and the conditions in the anammox process to use the reduced ammonium …


Periodicity In The Electrochemical Dissolution Of Transition Metals, Florian D. Speck, Alexandra Zagalskaya, Vitaly Alexandrov, Serhiy Cherevko Jan 2021

Periodicity In The Electrochemical Dissolution Of Transition Metals, Florian D. Speck, Alexandra Zagalskaya, Vitaly Alexandrov, Serhiy Cherevko

Department of Chemical and Biomolecular Engineering: Faculty Publications

Extensive research efforts are currently dedicated to the search for new electrocatalyst materials in which expensive and rare noble metals are replaced with cheaper and more abundant transition metals. Recently, numerous alloys, oxides, and composites with such metals have been identified as highly active electrocatalysts through the use of high-throughput screening methods with the help of activity descriptors. Up to this point, stability has lacked such descriptors. Hence, we elucidate the role of intrinsic metal/oxide properties on the corrosion behavior of representative 3d, 4d, and 5d transition metals. Electrochemical dissolution of nine transition metals is quantified using online inductively coupled …


Microsphere Photolithography Patterned Nanohole Array On An Optical Fiber, Ibrahem Jasim, Jiayu Liu, Chen Zhu, Muhammad Roman, Jie Huang, Edward Kinzel, Mahmoud Almasri Jan 2021

Microsphere Photolithography Patterned Nanohole Array On An Optical Fiber, Ibrahem Jasim, Jiayu Liu, Chen Zhu, Muhammad Roman, Jie Huang, Edward Kinzel, Mahmoud Almasri

Electrical and Computer Engineering Faculty Research & Creative Works

Microsphere Photolithography (MPL) is a nanopatterning technique that utilizes a self-assembled monolayer of microspheres as an optical element to focus incident radiation inside a layer of photoresist. The microspheres produces a sub-diffraction limited photonic-jet on the opposite side of each microsphere from the illumination. When combined with pattern transfer techniques such as etching/lift-off, MPL provides a versatile, low-cost fabrication method for producing hexagonal close-packed metasurfaces. This article investigates the MPL process for creating refractive index (RI) sensors on the cleaved tips of optical fiber. The resonant wavelength of metal elements on the surface is dependent on the local dielectric environment …


Building Services Engineering January/February Jan 2021

Building Services Engineering January/February

Building Services Engineering

No abstract provided.


Electrospun Fiber Scaffolds For Engineering Glial Cell Behavior To Promote Neural Regeneration, Devan L. Puhl, Jessica L. Funnell, Derek W. Nelson, Manoj K. Gottipati, Ryan J. Gilbert Jan 2021

Electrospun Fiber Scaffolds For Engineering Glial Cell Behavior To Promote Neural Regeneration, Devan L. Puhl, Jessica L. Funnell, Derek W. Nelson, Manoj K. Gottipati, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Electrospinning is a fabrication technique used to produce nano-or micro-diameter fibers to generate biocompatible, biodegradable scaffolds for tissue engineering applications. Electro spun fiber scaffolds are advantageous for neural regeneration because they mimic the structure of the nervous system extracellular matrix and provide contact guidance for regenerating axons. Glia are non-neuronal regulatory cells that maintain homeostasis in the healthy nervous system and regulate regeneration in the injured nervous system. Electro spun fiber scaffolds offer a wide range of characteristics, such as fiber alignment, diameter, surface nano topography, and surface chemistry that can be engineered to achieve a desired glial cell response …


Fiber-Optic And Coaxial-Cable Extrinsic Fabry-Perot Interferometers For Sensing Applications, Chen Zhu Jan 2021

Fiber-Optic And Coaxial-Cable Extrinsic Fabry-Perot Interferometers For Sensing Applications, Chen Zhu

Doctoral Dissertations

”The fiber-optic extrinsic Fabry-Perot interferometer (EFPI) is one of the simplest sensing configurations and is widely used in various applications due to its prominent features, such as high sensitivity, immunity to electromagnetic interference, and remote operation capability. In this research, a novel one-dimensional wide-range displacement sensor and a three-dimensional displacement sensor based on fiber-optic EFPIs are demonstrated. These two robust and easy-to-manufacture sensors expand the application scope of the fiber-optic EFPI sensor devices, and have great potential in structural health monitoring, the construction industry, oil well monitoring, and geo-technology.

Furthermore, inspired by the fiber-optic EFPI, a novel and universal ultra-sensitive …


Determination Of Extreme Flood Events In The Black Creek, Julington Creek, Dubin Creek, Big Davis Creek, Ortega River, And Pablo Creek Sub-Basins Of The Lower St. Johns River Basin, Florida, Usa, Samantha Kovalenko Jan 2021

Determination Of Extreme Flood Events In The Black Creek, Julington Creek, Dubin Creek, Big Davis Creek, Ortega River, And Pablo Creek Sub-Basins Of The Lower St. Johns River Basin, Florida, Usa, Samantha Kovalenko

UNF Graduate Theses and Dissertations

Extreme flood estimation is a continuously developing field of research. Economic and community well-being are dependent on flood risk preventative planning, which can only be successfully implemented through sound flood estimating methods. Without the execution of proper flood prevention measures, many communities remain at risk. In addition to a new extreme flood estimation methodology, this research presents a new approach to establish flood estimates. Traditionally, more than one flood estimate per return frequency storm does not exist. This research produced a set of 10-, 25-, 50-, and 100-year flood estimates for the Black Creek, Julington Creek, Durbin Creek, Big Davis …


Effects Of Corrosion On The Sers Activity And Optical Response Of Silver Nanorods, Christopher J. Mealer Jan 2021

Effects Of Corrosion On The Sers Activity And Optical Response Of Silver Nanorods, Christopher J. Mealer

UNF Graduate Theses and Dissertations

The nanoscience and nanotechnology community have a common goal in better understanding the surfaced enhanced Raman scattering (SERS) that occurs due to laser plasmon resonance in conjunction with metal enhanced substrates. Metallic nanostructures, such as silver (Ag) nanorods, are widely used in biological and chemical sensing applications that rely on the measurement of subtle changes in the optical response of the nanostructures in the presence of a target agent. The optical response of Ag nanorods and most other metallic nanostructures is highly sensitive to morphology and surface chemical termination. In pristine condition, the optical properties of Ag nanorods and other …


Safety Analysis Of Battery-Powered Adaptive Ride-On Toys For Children With Disabilities, Abbey Fraser Jan 2021

Safety Analysis Of Battery-Powered Adaptive Ride-On Toys For Children With Disabilities, Abbey Fraser

UNF Graduate Theses and Dissertations

Modified battery-powered ride-on toy cars, or adaptive ride-on toys, represent novel rehabilitation tools and developmental aids for children with disabilities. Studies have shown that children are benefiting socially and developmentally from their use. However, the use of these toys by children with disabilities potentially poses a risk of injury and it is vitally important to ensure the safe use of these toys, particularly for the benefit of those with developmental challenges.

Within this context, the purpose of the first study was to determine whether modifications to ride-on toys are sufficient to prevent common modes of injury such as falls, passenger …


A Transdisciplinary Analysis Of Just Transition Pathways To 100% Renewable Electricity, Adewale Aremu Adesanya Jan 2021

A Transdisciplinary Analysis Of Just Transition Pathways To 100% Renewable Electricity, Adewale Aremu Adesanya

Dissertations, Master's Theses and Master's Reports

The transition to using clean, affordable, and reliable electrical energy is critical for enhancing human opportunities and capabilities. In the United States, many states and localities are engaging in this transition despite the lack of ambitious federal policy support. This research builds on the theoretical framework of the multilevel perspective (MLP) of sociotechnical transitions as well as the concept of energy justice to investigate potential pathways to 100 percent renewable energy (RE) for electricity provision in the U.S. This research seeks to answer the question: what are the technical, policy, and perceptual pathways, barriers, and opportunities for just transition to …


Impact Of Hemodynamic Vortex Spatial And Temporal Characteristics On Analysis Of Intracranial Aneurysms, Kevin W. Sunderland Jan 2021

Impact Of Hemodynamic Vortex Spatial And Temporal Characteristics On Analysis Of Intracranial Aneurysms, Kevin W. Sunderland

Dissertations, Master's Theses and Master's Reports

Subarachnoid hemorrhage is a potentially devastating pathological condition in which bleeding occurs into the space surrounding the brain. One of the prominent sources of subarachnoid hemorrhage are intracranial aneurysms (IA): degenerative, irregular expansions of area(s) of the cerebral vasculature. In the event of IA rupture, the resultant subarachnoid hemorrhage ends in patient mortality occurring in ~50% of cases, with survivors enduring significant neurological damage with physical or cognitive impairment. The seriousness of IA rupture drives a degree of clinical interest in understanding these conditions that promote both the development and possible rupture of the vascular malformations. Current metrics for the …


Marangoni Propulsion Of Active Particles, Saeed Jafari Kang Jan 2021

Marangoni Propulsion Of Active Particles, Saeed Jafari Kang

Dissertations, Master's Theses and Master's Reports

We study the surfing motion of active particles located at a flat liquid-gas interface. The particles create and maintain a surface tension gradient by asymmetrically discharging a surface tension-reducing agent. We employ theory and numerical simulation to investigate the Marangoni propulsion of these active surfers. First, we use the reciprocal theorem to establish a relationship between the propulsion speed and the release of the active chemical. This theoretical relation is utilized to examine the effect of wall confinement and geometry on the Marangoni-driven motion of active particle when the inertial effects are negligible and when the transports of the released …


Multi-Dimensional Modeling For Environmental Impact Assessment At Intersections Of The Food-Energy-Water Nexus, Jessica Daignault Jan 2021

Multi-Dimensional Modeling For Environmental Impact Assessment At Intersections Of The Food-Energy-Water Nexus, Jessica Daignault

Dissertations, Master's Theses and Master's Reports

This dissertation uses multi-dimensional modeling for environmental impact assessment at intersections of the Food-Energy-Water (FEW) Nexus, including life cycle assessment (LCA) modeling for quantification of environmental impacts due to household FEW consumption, a linear regression framework for quantification of water-use impacts of marginal electricity generation, and a multi-objective optimization model to assess monetization of water withdrawals for electricity generation and impacts to water stress due to electricity dispatch schemes. Chapter 2 of this dissertation summarizes the development of an LCA model that quantifies the direct and indirect environmental impacts of household FEW consumption. The model is executed through a novel …


Investigation Of A Machine-Plant Interface For Extracting Rooted Invasive Aquatic Plants, Brad Baas Jan 2021

Investigation Of A Machine-Plant Interface For Extracting Rooted Invasive Aquatic Plants, Brad Baas

Dissertations, Master's Theses and Master's Reports

The current solutions for managing rooted aquatic invasive plants are time consuming, have negative environmental impacts, or are cost-limiting for management organizations. The most effective treatment method is hand pulling, but hand pulling is not a feasible solution for a whole lake. A new device, the invasive aquatic plant extractor, aims to replace human divers who hand pull plants with a mechanical system. The device implements a machine-plant interface that resembles the tines of a fork. These tines will be pushed linearly through the substrate, and then raised from the substrate with the plant caught in the tines. The primary …


Anaerobic Reductive Bioleaching Of Manganese Ores, Neha Sharma Jan 2021

Anaerobic Reductive Bioleaching Of Manganese Ores, Neha Sharma

Dissertations, Master's Theses and Master's Reports

The increasing demand of manganese in the industries and various hindrances in its production from low grade ores by conventional method has made it imperative for researchers around the world to develop a method of manganese extraction from low grade ores that is both environment friendly and economical. Bioleaching has shown significant potential in manganese extraction and efficiencies of extraction have been found to be 70-98% with the help of various bacteria and fungi.

This study focuses on extraction of manganese with the help of mixed bacterial strains that have been collected from their natural anaerobic environment. The extraction of …


Design And Testing Of An Open Source Vacuum Oven For Research, Community Recycling, And Additive Manufacturing, Benjamin R. Hubbard Jan 2021

Design And Testing Of An Open Source Vacuum Oven For Research, Community Recycling, And Additive Manufacturing, Benjamin R. Hubbard

Dissertations, Master's Theses and Master's Reports

To aid the continuing growth of open source tools in the research community, this thesis presents two broadly useful instruments which can be built and operated for a fraction of the cost of equivalent or inferior commercial products. The first device is a digitally-replicable scale, which provides a single framework for making measurements on the order of milligrams all the way up to tens of kilograms by supporting multiple types of load cells. The second device is a vacuum oven, which is validated using the first. The open source vacuum oven facilitates the dehydration of materials at low temperature, providing …


The Extraction Of Waxes And Lipids From Sorghum Using Green And Renewable Solvents Followed By Conversion To Biofuels Using Gamma-Valerolactone Pretreatment, Marissa Gallmeyer Jan 2021

The Extraction Of Waxes And Lipids From Sorghum Using Green And Renewable Solvents Followed By Conversion To Biofuels Using Gamma-Valerolactone Pretreatment, Marissa Gallmeyer

Dissertations, Master's Theses and Master's Reports

Plant matter contains waxes and lipids that can be extracted and used or sold as a value-added product prior to conversion of the remaining plant material to biofuels. Wax and lipid extraction of plant materials is currently performed using volatile, non-renewable hydrocarbons, primarily hexane, which is produced from fossil fuels and can pose a health and safety hazard. The purpose of this study is to compare the amount and characteristics of waxes extracted by hexane with those extracted using organic solvents that are less toxic and can be produced from renewable sources.

Sorghum samples were extracted separately with hexane, 2-methyltetrahydrofuran …


The Application Of Leaky Wave Antennas For Medical Hyperthermia Treatment And Beamformer In Fmcw Automotive Radar Systems, Masoud Sarabi Jan 2021

The Application Of Leaky Wave Antennas For Medical Hyperthermia Treatment And Beamformer In Fmcw Automotive Radar Systems, Masoud Sarabi

Dissertations, Master's Theses and Master's Reports

Thousands of years ago human discovered that if a slice of amber is rubbed against fur, it would absorb light-weight objects. Hundreds of years after that the ancient people figured out that there are actually two different characteristics of attraction and repulsion. Another 2000 years passed when human discovered that these two wonders of nature, magnetism and electricity are actually linked together like the two sides of the same coin. Since then, in the early 19th century great huge achievements were made in antennas and propagation by scientists such as Hans Christen Oersted, Heinrich Hertz, Alexander Popov and Marconi. Since …


Prediction Of Emg Activation Profiles From Gait Kinematics And Kinetics During Multiple Terrains, Erika V. Zabre-Gonzalez, Diego Amieva-Alvarado, Scott A. Beardsley Jan 2021

Prediction Of Emg Activation Profiles From Gait Kinematics And Kinetics During Multiple Terrains, Erika V. Zabre-Gonzalez, Diego Amieva-Alvarado, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

Continuous myoelectric prediction of intended limb dynamics has the ability to provide transparent control of a prosthesis by the user. However, the impact on these models of adding a human user into the control loop is less clear. Here, the ability of a User Response Model (URM) to continuously predict EMG activity from gait kinematics and kinetics collected during three mobility tasks (level-ground walking, stair ascent, and stair descent) was examined. Multiple-input, multiple-output NARX-based URMs were developed with two outputs (ankle plantarflexor and dorsiflexor) and variable inputs (ankle kinetics, and shank and/or ankle kinematics). Accuracy in predicting the tibialis anterior …


Theoretical Study Of Magnetic Particles In A Shear Flow Subjected To A Uniform Magnetic Field, Christopher A. Sobecki Jan 2021

Theoretical Study Of Magnetic Particles In A Shear Flow Subjected To A Uniform Magnetic Field, Christopher A. Sobecki

Doctoral Dissertations

"Magnetic manipulation of non-spherical magnetic microparticles is important for applications in shape-based and magnetic-based separations such as waste management, disease diagnostics, drug delivery, and mining. Manipulations of magnetic microparticles also include chain formation to assemble compositions for electronics, drug loading designs, and magnetorheological fluids for smart armor, hydraulic brakes, and dampers. In microfluidic devices, separation-formation-effectiveness depends on the shape of the channel, the shear rate, and the magnetic field strength and direction.

Particle separation and chain formation involved highly complex and computational expense-demanding studies in microfluidic devices, magnetic fields, and particle- particle/wall interactions. This research took complex experimental studies and …


Semi-Empirical Modeling Of Liquid Carbon's Containerless Solidification, Philip C. Chrostoski Jan 2021

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

Doctoral Dissertations

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


Cyclic Sequential Adsorption Desorption/Thermal-Catalytic Oxidation Of Volatile Organic Compounds: Material Development, Process Advancement/Improvement, And Numerical Modeling, Simulation And Optimization, Busuyi Ojo Adebayo Jan 2021

Cyclic Sequential Adsorption Desorption/Thermal-Catalytic Oxidation Of Volatile Organic Compounds: Material Development, Process Advancement/Improvement, And Numerical Modeling, Simulation And Optimization, Busuyi Ojo Adebayo

Doctoral Dissertations

"Volatile organic compounds (VOCs) are a group of useful organic chemicals but when emitted have contributed to air pollution. They affect human health, cause environmental degradation and contaminate our waters and soils, so they need to be controlled. When they exist in dilute concentrations, abatement becomes challenging, thus requiring advanced abatement methods, e.g., sequential adsorption desorption/thermal-catalytic oxidation process. The overall goal of this research was to abate dilute streams of VOCs via the process. The specific objectives were to 1) develop novel adsorbent/catalyst dual-function materials (DFMs) for the process, 2) improve the operability of a one-bed-one-column reactor configuration for the …


ผลของความหยาบผิวของโลหะผสม Ti-6al-4v ที่ขึ้นรูปด้วยวิธีการพิมพ์สามมิติต่อลักษณะทางสัณฐานวิทยาของท่อนาโนไทเทเนียมไดออกไซด์และความต้านทานการกัดกร่อน, ปาณิสรา พุทธสุวรรณ Jan 2021

ผลของความหยาบผิวของโลหะผสม Ti-6al-4v ที่ขึ้นรูปด้วยวิธีการพิมพ์สามมิติต่อลักษณะทางสัณฐานวิทยาของท่อนาโนไทเทเนียมไดออกไซด์และความต้านทานการกัดกร่อน, ปาณิสรา พุทธสุวรรณ

Chulalongkorn University Theses and Dissertations (Chula ETD)

นอกจากวัสดุไทเทเนียมจะนิยมนำมาใช้เป็นวัสดุทดแทนกระดูกหรือข้อต่อที่เสียหายเนื่องจากมีสมบัติที่ดีในเรื่องของความแข็งแรงสูง มีความต้านทานการกัดกร่อนสูงและมีความเข้ากันได้ทางชีวภาพแล้ว การสร้างท่อนาโนไทเทเนียมไดออกไซด์ก็ใช้กันอย่างแพร่หลายในการปรับสภาพผิววัสดุเช่นกัน เนื่องจากช่วยส่งเสริมการยึดเกาะของเซลล์และให้การตอบสนองของเซลล์ได้ดีกว่าพื้นผิวโลหะเอง แม้มีการศึกษาหลายชิ้นได้รายงานความสัมพันธ์ระหว่างท่อนาโนไทเทเนียมไดออกไซด์กับอัตราการเชื่อมประสานของเซลล์ แต่อย่างไรก็ตามอัตราการกัดกร่อนของชั้นท่อนาโนไทเทเนียมไดออกไซด์ภายใต้สภาวะการใช้งานนั้น ๆก็มีความจำเป็นที่ต้องศึกษาเช่นกัน ในงานนี้เราได้ศึกษาผลจากการปรับสภาพผิวที่ถูกเตรียมด้วยเงื่อนไขต่าง ๆ ต่อพฤติกรรมการกัดกร่อนของวัสดุ Ti-6Al-4V และลักษณะทางสัณฐานวิทยาของชั้นท่อนาโนไทเทเนียมไดออกไซด์ซึ่งการศึกษาจะแบ่งเป็น 2 กลุ่มคือกลุ่มที่ทำการปรับสภาพผิวด้วยการขัดและกลุ่มที่ทำการปรับสภาพผิวด้วยการขัดต่อด้วยการแอโนไดซ์ โดยจะทำการวัดความหยาบพื้นผิวที่เตรียมได้ก่อนการแอโนไดซ์โดยเครื่องวัดความหยาบผิวและศึกษาลักษณะพื้นผิวหลังแอโนไดซ์ด้วยกล้องจุลทรรศน์อิเล็กตรอนแบบส่องกราดและศึกษาพฤติกรรมการกัดกร่อนในสารละลายฟอตเฟสบัฟเฟอร์ซาลีนโดยเทคนิคโพเท็นชิโอไดนามิกโพลาไรเซชัน ผลการวิจัยชี้ให้เห็นว่าก่อนการแอโนไดซ์ความหยาบผิวที่เตรียมได้ไม่มีความสัมพันธ์กับอัตราการกัดกร่อนโดยตรง แต่อย่างไรก็ตามหลังจากแอโนไดซ์พบว่าความหยาบผิวตั้งต้นจากการเตรียมผิวก่อนแอโนไดซ์มีผลต่อลักษณะการเกิดท่อนาโนไทเทเนียมไดออกไซด์ รวมถึงอัตราการกัดกร่อนมีความสัมพันธ์กับขนาดเส้นผ่านศูนย์กลาง ค่าส่วนเบี่ยงเบนมาตรฐานของขนาดเส้นผ่านศูนย์กลางท่อและลักษณะการเรียงตัวของท่อที่เกิดขึ้น


Fabrication And Optimization Of Thin Film Composite Membrane Incorporated With Tio2 Nanoparticles To Enhance Anti-Fouling Property, Sasakorn Charoenyuenyao Jan 2021

Fabrication And Optimization Of Thin Film Composite Membrane Incorporated With Tio2 Nanoparticles To Enhance Anti-Fouling Property, Sasakorn Charoenyuenyao

Chulalongkorn University Theses and Dissertations (Chula ETD)

The polyamide thin-film composite (PA-TFC) membranes containing the titanium dioxide nanoparticles (TiO2 NPs) were developed to improve the membrane performances, especially the anti-fouling properties such as normalized flux and flux recovery. The selective thin-film layer was fabricated over polysulfone (PSf) through the interfacial polymerization (IP) of m-phenylenediamine (MPD) and 1,3,5-benzenetricarbonyl chloride (TMC) monomers. The response surface methodology (RSM) with Box-Behnken strategy was applied to find the optimal fabrication condition of TiO2, pH, ethyl alcohol in MPD solution that could obtain the best overall performances for the synthesized membranes. The result indicated that the addition of TiO2 NPs together with ethyl …


Centuries Of Heat Waves Over India During 20th And 21st Century, Naveena Neelam, Gubbala C. Satyanerayana, Kotla S. Rao, Nandivada Umakantha, Dharma Raju Jan 2021

Centuries Of Heat Waves Over India During 20th And 21st Century, Naveena Neelam, Gubbala C. Satyanerayana, Kotla S. Rao, Nandivada Umakantha, Dharma Raju

Applied Environmental Research

An assessment of temperature extremes is made for the Indian subcontinent to identify the changes since 1951 to 2015, and for the future climate periods till 2100 for all the 21 CMIP5 (Coupled Model intercomparision Project phase 5) models and the representative concentration pathways RCP4.5 and RCP8.5 were examined for the period from 1 March to 31 May to characterize the heat waves in future climates and mean maximum and mean minimum bias were evaluated for the Indian subcontinent. Later two highest recorded temperature regions were chosen Northwest & Central India (NW&CIN) and only central India (CIN) box and the …