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Rare Earth/Transition Metal Oxides For Syngas Cleanup, Rui Li
Rare Earth/Transition Metal Oxides For Syngas Cleanup, Rui Li
LSU Doctoral Dissertations
Syngas from gasification of biomass or biomass and coal is a potential source of renewable energy. However, byproducts such as H2S and tars must be removed before further utilization or processing of syngas. Rare earth oxides (REOs, e.g., Ce/LaOx (1.7< x <2)) mixed with transition metals (e.g., Mn, Fe) were synthesized by various methods, and in some cases supported on a thermally stable alumina. Both desulfurization and tar reforming experiments were conducted at high temperatures under similar conditions with synthetic effluents in order to achieve better heat integration and higher yield to desired products CO and H2. The sulfur capacities at temperatures from 900-1025 K with air regeneration were measured for repeat cycles until a stable, reversible capacity was obtained. The oxidized and sulfided (reduced) sorbents were characterized by XRD, XANES, XAFS, TPR and BET. Density functional theory calculations were used to aid in interpreting characterization data and in explaining the enhanced S adsorption capacities. The results showed that mixed REOs, such as Ce/Tb, and Ce/La synthesized by a templated sol-gel approach do not have high sulfur capacities. The presence of either CO2 or H2O inhibits the adsorption of H2S. However, addition of Mn to REOs effectively increased the sulfur capacity, and Mn-REO sorbents are regenerable even in the presence of air, although there is some sulfate formation. The formation of elemental sulfur during regeneration could be related to the oxygen vacancies promoted by doping Mn into the ceria lattice. DFT calculations suggested doping Mn into CeO2 decreased the vacancy formation energies and lowered the H2S adsorption energy. In contrast, for MnO-doped REOs supported on ã-Al2O3, although their surface areas remained high after multi-cycle usage, the probable formation of MnAl2O4 as observed by XANES reduces the sulfur capacities. Reforming experiments were carried out using synthetic syngas mixtures with C10H8 as a tar model compound, both with and without H2S. The results showed that CO2 and H2O inhibit the reforming activities to some extent. Fe- or Mn-doped supported REOs are promising tar cleanup catalysts. They exhibited higher sulfur tolerance, less coking, and less methanation than typical Ni-based high temperature reforming catalysts. This behavior is in part attributed to enhanced generation of oxygen vacancies in the doped REOs.
Advanced And Novel Modeling Techniques For Simulation, Optimization And Monitoring Chemical Engineering Tasks With Refinery And Petrochemical Unit Applications, Gregory M. Robertson
Advanced And Novel Modeling Techniques For Simulation, Optimization And Monitoring Chemical Engineering Tasks With Refinery And Petrochemical Unit Applications, Gregory M. Robertson
LSU Doctoral Dissertations
Engineers predict, optimize, and monitor processes to improve safety and profitability. Models automate these tasks and determine precise solutions. This research studies and applies advanced and novel modeling techniques to automate and aid engineering decision-making. Advancements in computational ability have improved modeling software’s ability to mimic industrial problems. Simulations are increasingly used to explore new operating regimes and design new processes. In this work, we present a methodology for creating structured mathematical models, useful tips to simplify models, and a novel repair method to improve convergence by populating quality initial conditions for the simulation’s solver. A crude oil refinery application …
Electrochemical Reduction Of Co2 On Supported Cu2o Catalysts, Joel Niño Galvez Bugayong
Electrochemical Reduction Of Co2 On Supported Cu2o Catalysts, Joel Niño Galvez Bugayong
LSU Doctoral Dissertations
We have examined Cu-based catalyst materials that enable the conversion of CO2 to useful products such as fuels and chemical feedstocks by electrochemical reduction. In particular, we compared the electrocatalytic activity of supported Cu2O particles prepared using electrodeposition and wet chemical methods. The particles had cubic structure, ranging in size from 40 nm to 900 nm and consisting of low index planes. We observed significantly different product distribution on these catalysts compared to polycrystalline Cu, specifically for methane and ethylene formation. While Cu particles showed higher faradaic efficiency for methane formation compared to ethylene formation, we observed that Cu2O particles …
Energy And Thermodynamically Based Approaches For Analysis Of Damage In Contact Problems, Afshin Babaie Aghdam
Energy And Thermodynamically Based Approaches For Analysis Of Damage In Contact Problems, Afshin Babaie Aghdam
LSU Doctoral Dissertations
A novel methodology for analysis of damage in contact problems in presented. Two important categories of contact damage are studied, namely crack nucleation and adhesive wear. The proposed methodology is primarily based on the laws of energy and thermodynamics, and as such offers great advantages by unifying the analysis of damage in a variety of contact configurations. Crack nucleation is the first damage type analyzed. For this purpose, the line-contact fretting configuration is chosen. A thermodynamically-based continuum damage mechanics (CDM) approach is employed. Intense stress gradients in the contact region are found to be highly influential in the crack nucleation …
Spectrum Sensing, Spectrum Monitoring, And Security In Cognitive Radios, Erfan Soltanmohammadi
Spectrum Sensing, Spectrum Monitoring, And Security In Cognitive Radios, Erfan Soltanmohammadi
LSU Doctoral Dissertations
Spectrum sensing is a key function of cognitive radios and is used to determine whether a primary user is present in the channel or not. In this dissertation, we formulate and solve the generalized likelihood ratio test (GLRT) for spectrum sensing when both primary user transmitter and the secondary user receiver are equipped with multiple antennas. We do not assume any prior information about the channel statistics or the primary user’s signal structure. Two cases are considered when the secondary user is aware of the energy of the noise and when it is not. The final test statistics derived from …
The Effects Of Concurrent Driving And In-Vehicle Tasks: A Multivariate Statistical Analysis Of Driver Distraction In A High-Fidelity Driving Simulator, Julius A. Codjoe
The Effects Of Concurrent Driving And In-Vehicle Tasks: A Multivariate Statistical Analysis Of Driver Distraction In A High-Fidelity Driving Simulator, Julius A. Codjoe
LSU Doctoral Dissertations
Distracted driving continues to remain a cause of concern for a number of bodies, including government agencies, traffic safety advocacy groups and law enforcement agencies, because of its traffic safety risks. The driving simulator continues to be popular with researchers in collecting data on performance variables that provide scientific knowledge of the effects of distracted driving. Several of these performance variables can be used to quantify a single distracting effect, resulting in a multivariate dataset. A literature review of related studies revealed that researchers overwhelmingly use univariate (single and multiple) tests to analyze the resulting dataset. Performing multiple univariate tests …
Evaluation Of Triploid Oysters As A Tool To Assess Short- And Long-Term Seafood Contamination Of Oil Spill-Impacted Areas, Martin Scott Miles
Evaluation Of Triploid Oysters As A Tool To Assess Short- And Long-Term Seafood Contamination Of Oil Spill-Impacted Areas, Martin Scott Miles
LSU Doctoral Dissertations
Many of the organic components of oil have the capacity to persist in the environment, bioaccumulate in tissues, and are toxic to surrounding organisms. Since the early 1970s, environmental assessment programs have utilized bivalves as monitoring tools of chemical contaminants in the marine environment. Because of their sedentary and filter-feeding habit (bioaccumulation), mussels and oysters been employed as sentinel organisms in environmental quality monitoring studies in coastal ecosystems. The use of indigenous (diploid) bivalves for biomonitoring water quality is limited during the summer months due to high stress and changes in biochemical composition induced by reproductive development. In this work …
Polycyclic Aromatic Hydrocarbon Degradation In Tidally Influenced Coastal Marsh Wetland Studied In Laboratory Mesocosm, Doorce S. Batubara
Polycyclic Aromatic Hydrocarbon Degradation In Tidally Influenced Coastal Marsh Wetland Studied In Laboratory Mesocosm, Doorce S. Batubara
LSU Doctoral Dissertations
The compact mesocosm which was designed for a laboratory scale was used for the kinetic study of refractory organic compounds in a tidally influenced coastal marsh wetland soil. The tidal cycles were controlled pneumatically using an air chamber inside the mesocosm tank. Phenanthrene as the test compound showed that its degradation in the intertidal wetland soil was faster than that in the subtidal wetland soil. Oxygen resupply during the tidal cycles to the intertidal wetland soil would enhance the degradation. Comparison of degradation rates of phenanthrene (Phe), pyrene (Pyr), and benzo[e]pyrene (BeP) were also studied using the mesocosm. The degradation …
Multiscale Estimation Of Inertial Effects For Frac-Pack Completed Gas Reservoirs, Sultan Anbar
Multiscale Estimation Of Inertial Effects For Frac-Pack Completed Gas Reservoirs, Sultan Anbar
LSU Doctoral Dissertations
Accurate estimation of production from frac-pack completed gas wells requires reliable estimation of flow properties from reservoir rocks and proppants. This study is composed of three parts: core-scale, pore-scale and reservoir-scale analyses of this problem. In the core-scale analysis, simultaneous estimation of permeability, non-Darcy, and Klinkenberg coefficients of reservoir rock is conducted from steady-state and pulse-decay experiments. Confidence intervals of the estimated parameters are determined from the Bootstrap method. The duration of pulse-decay experiments has a large impact on confidence intervals; therefore, correlations are developed to estimate the experimental duration for both 1-tank and 2-tank set-ups from the core properties …
A System Approach To Investing In Uncertain Markets, Iman Khademi
A System Approach To Investing In Uncertain Markets, Iman Khademi
LSU Doctoral Dissertations
We consider the problem of trend-following in US stock market and propose a combined economic and technical model to approach this problem. A bank of linear and nonlinear, discrete-time, low-pass filters with different sampling rates is used to generate timing signals for US stock market indexes such as NASDAQ Composite and S&P 500. These timing signals help us find the appropriate times to step in or out of the market. Back-testing and real-time implementation results along with the risk analysis validate our model. According to the trend of the market, we may adopt a long or short position. If we …
Damage Prediction Of Low-Rise Buildings Under Hurricane Winds, Fang Pan
Damage Prediction Of Low-Rise Buildings Under Hurricane Winds, Fang Pan
LSU Doctoral Dissertations
Low-rise buildings are defined as the buildings with a mean roof height less than the least horizontal dimension and less than 18.3 m in ASCE 7-10. They represent the majority of commercial, residential, and industrial buildings. Approximate 90% of the existing low-rise residential buildings are constructed as wood light-frame buildings that are not fully engineered and thus more vulnerable to extreme wind pressures, wind borne debris and rain water intrusion. The resulting hurricane-induced economic loss is primarily attributed to the insufficient performance of building envelope instead of the catastrophic failure of their main structural system for Category 1 to 4 …
Numerical Investigation Of Cryopreserved Zebrafish Sperm Cell Activation In Microchannels, Thomas Foster Scherr
Numerical Investigation Of Cryopreserved Zebrafish Sperm Cell Activation In Microchannels, Thomas Foster Scherr
LSU Doctoral Dissertations
This aim of this research project is to probe the activation process of zebrafish spermatozoa. Zebrafish are a model species for biological engineering applications, and the cryopreservation of their reproductive cells allows for inexpensive cataloging and maintenance of valuable biological material. Evaluation of cryopreservation protocols for aquatic sperm cells is typically accomplished by motility analysis after subjecting cells to a cryopreservation treatment. In zebrafish sperm cells, motility is initiated when cells come into contact with a hypo-osmotic environment. Subsequent activation analysis is currently done manually and brings with it an inherent difficulty and error. This process is slow and not …
The Effects Of Asymmetric Micro Ratchets On Pool Boiling Performance, Lance Austin Brumfield
The Effects Of Asymmetric Micro Ratchets On Pool Boiling Performance, Lance Austin Brumfield
LSU Doctoral Dissertations
Nucleate boiling is an attractive method for achieving high heat flux at low superheat temperatures. It is frequently used for industrial applications such as heat exchangers and is being considered to cool advanced central processing units (CPU) which produce heat fluxes on the order of 1 MW/m2 and are becoming increasingly less efficient to cool via forced conduction of air. The issue with implementing nucleate boiling as a cooling mechanism lies in the difficulty of quantifying the numerous and complex mechanisms which control the process. A comprehensive nucleate boiling model has yet to be formulated and will be required in …
Advanced Statistical Signal Processing Methods In Sensing, Detection, And Estimation For Communication Applications, Hongting Zhang
Advanced Statistical Signal Processing Methods In Sensing, Detection, And Estimation For Communication Applications, Hongting Zhang
LSU Doctoral Dissertations
The applications of wireless communications and digital signal processing have dramatically changed the way we live, work, and learn over decades. The requirement of higher throughput and ubiquitous connectivity for wireless communication systems has become prevalent nowadays. Signal sensing, detection and estimation have been prevalent in signal processing and communications for many years. The relevant studies deal with the processing of information-bearing signals for the purpose of information extraction. Nevertheless, new robust and efficient signal sensing, detection and estimation techniques are still in demand since there emerge more and more practical applications which rely on them. In this dissertation work, …
Catalytic Active Site, Mechanistic And Kinetic Studies Of Dry (Co2) Reforming Of Methane Over Lanthanum Zirconate (La2zr2o7) Pyrochlores, Devendra Pakhare
Catalytic Active Site, Mechanistic And Kinetic Studies Of Dry (Co2) Reforming Of Methane Over Lanthanum Zirconate (La2zr2o7) Pyrochlores, Devendra Pakhare
LSU Doctoral Dissertations
Dry (CO2) reforming of CH4 (DRM) produces commercially important synthesis gas (H2 and CO) with H2/CO ≤ 1, which can be used for synthesis of higher alkanes and oxygenates. DRM is highly endothermic and requires temperatures as high as 800°C-1000°C to attain high equilibrium conversions. A major problem associated with DRM is catalyst deactivation due to carbon deposition. Thus it is imperative that the catalyst used for DRM must resist deactivation due to sintering and carbon deposition. DRM is well studied in the literature over various catalysts, however, there is no literature, except the Ashcroft (1993) article, for DRM over …
Crack Self-Healing In Sic/Spinel Nanocomposite, Fariborz Tavangarian
Crack Self-Healing In Sic/Spinel Nanocomposite, Fariborz Tavangarian
LSU Doctoral Dissertations
Spinel is one of the best known and widely used ceramic materials. It has good thermal shock resistance, high chemical inertness in both acidic and basic environments, excellent optical and dielectric properties, high strength at both elevated and normal temperatures, and has no phase transition up to the melting temperature (2135°C). Spinel is used in the metallurgical, electrochemical, and chemical industrial fields. It has also found some applications in dentistry, catalyst supports, humidity sensors, reinforcing fibers, photoluminescent materials, etc. One of the limitations of spinel ceramic is its brittleness. Furthermore, at high temperature applications, a rapid heating or cooling can …
Utilization Of Carbon Nanofibers Grown On Glass Microballoons (Nmbs) In Point-Of-Care Diagnostic Devices, Emmanuel Gikunoo
Utilization Of Carbon Nanofibers Grown On Glass Microballoons (Nmbs) In Point-Of-Care Diagnostic Devices, Emmanuel Gikunoo
LSU Doctoral Dissertations
The use of point-of-care (POC) diagnostic systems holds great promise for the early detection of various diseases. However, detection limits for commercially available POC systems have not been able to meet the lower cutoffs offered by the specialized laboratory testing methods. Research into the use of carbon nanofibers (CNFs) grown on glass microballoons in POC devices was studied. The growth of several millions of the CNFs on each microballoon (NMBs) presented a large surface area with high probability of capturing minute concentrations of biospecies. Functionalization of the NMBs with the carboxyl group needed for biospecies conjugation was achieved by air …
Hot Corrosion Behaviour Of New Candidates For Thermal Barrier Coatings Application In Turbine Simulated Environments, Mohammad Hamed Habibi
Hot Corrosion Behaviour Of New Candidates For Thermal Barrier Coatings Application In Turbine Simulated Environments, Mohammad Hamed Habibi
LSU Doctoral Dissertations
Thermal barrier coatings (TBCs) are used gas turbine engines. The current material of choice (YSZ) degrades when it contacts with impurities arise from low quality fuels such vanadium and sulfur. YSZ cannot be used in temperature higher than 900˚C. Higher efficiency and performance of gas turbine engines will require a new generation of thermal barrier coatings (TBCs). In current work, hot corrosion behavior of new candidates including Gd2Zr2O7, ZrO2 stabilized with Ta2O5, zirconia stabilized with both Ta2O5 and Y2O3 and zirconia stabilized with CeO2 and TiO2 is investigated. For YSZ case, the reaction between NaVO3 and Y2O3 produces YVO4 and …
Bayesian Saltwater Intrusion Prediction And Remediation Design Under Uncertainty, Nima Chitsazan
Bayesian Saltwater Intrusion Prediction And Remediation Design Under Uncertainty, Nima Chitsazan
LSU Doctoral Dissertations
Groundwater resources are vital for sustainable economic and demographic developments. Reliable prediction of groundwater head and contaminant transport is necessary for sustainable management of the groundwater resources. However, the groundwater simulation models are subjected to uncertainty in their predictions. The goals of this research are to: (1) quantify the uncertainty in the groundwater model predictions and (2) investigate the impact of the quantified uncertainty on the aquifer remediation designs. To pursue the first goal, this study generalizes the Bayesian model averaging (BMA) method and introduces the hierarchical Bayesian model averaging (HBMA) method that segregates and prioritizes sources of uncertainty in …
Synthesis And Characterization Of Novel Polyester Scaffolds From Sugarcane Industry By-Products For Use In Skin And Bone Tissue Engineering, Akanksha Kanitkar
Synthesis And Characterization Of Novel Polyester Scaffolds From Sugarcane Industry By-Products For Use In Skin And Bone Tissue Engineering, Akanksha Kanitkar
LSU Doctoral Dissertations
The aim of this work was to synthesize non-toxic, biodegradable polyesters of aconitic acid, cinnamic acid and glycerol from by-products of the sugarcane industry as scaffolds for skin and bone tissue engineering. Utilizing the by-products, molasses and sugarcane bagasse, not only add value to the cane industry, but also paves path for synthesizing novel bio-based materials from the isolated specialty chemicals. Molasses contain an economically recoverable quantity of aconitic acid and its extraction was studied in detail as a part of this work. The yields of recovered aconitic acid varied from 25–69% depending on the extraction conditions. Under all the …
Image Enhancement Methods And Applications In Computational Photography, Qinchun Qian
Image Enhancement Methods And Applications In Computational Photography, Qinchun Qian
LSU Doctoral Dissertations
Computational photography is currently a rapidly developing and cutting-edge topic in applied optics, image sensors and image processing fields to go beyond the limitations of traditional photography. The innovations of computational photography allow the photographer not only merely to take an image, but also, more importantly, to perform computations on the captured image data. Good examples of these innovations include high dynamic range imaging, focus stacking, super-resolution, motion deblurring and so on. Although extensive work has been done to explore image enhancement techniques in each subfield of computational photography, attention has seldom been given to study of the image enhancement …
Novel Syntheses And Surface Modifications Of Electrode Materials For Superior Lithium-Ion Batteries, Jianqing Zhao
Novel Syntheses And Surface Modifications Of Electrode Materials For Superior Lithium-Ion Batteries, Jianqing Zhao
LSU Doctoral Dissertations
Rechargeable lithium-ion battery is one of the most promising energy conversion and storage systems that offers high energy and powder densities, long service life and assuring safety. Performance of lithium-ion batteries crucially relies on electrochemical characteristics of electrode materials, i.e., anode and cathode materials. This dissertation work aims at developing novel electrode materials with high capacity, excellent cycling stability and remarkable rate capability for next-generation lithium-ion batteries. The effects of surface modifications for LiMn2O4 cathode materials are studied by depositing ultrathin conformal amphoteric oxides via atomic layer deposition (ALD). In the case of ZnO coating, the thickness of ZnO ALD …
Piezoelectric Based Energy Harvesting On Low Frequency Vibrations Of Civil Infrastructures, Ye Zhang
Piezoelectric Based Energy Harvesting On Low Frequency Vibrations Of Civil Infrastructures, Ye Zhang
LSU Doctoral Dissertations
Piezoelectric-based energy harvesting is an efficient way to convert ambient vibration energy into usable electric energy. The piezoelectric harvester can work as a sustainable and green power source for different electric devices such as sensors and implanted medical devices. However, its application on civil infrastructures has not been fully studied yet. This dissertation aimed to study and improve the piezoelectric-based energy harvesting on civil infrastructures, especially on bridge structures. To reach the objective, a more accurate model for piezoelectric composite beams was built first, which can be adopted for the modeling of different kinds of energy harvesters. The model includes …
Image-Based Pore-Scale Modeling Of Inertial Flow In Porous Media And Propped Fractures, Yijie Shen
Image-Based Pore-Scale Modeling Of Inertial Flow In Porous Media And Propped Fractures, Yijie Shen
LSU Doctoral Dissertations
Non-Darcy flow is often observed near wellbores and in hydraulic fractures where relatively high velocities occur. Quantifying additional pressure drop caused by non-Darcy flow and fundamentally understanding the pore-scale inertial flow is important to oil and gas production in hydraulic fractures. Image-based pore-scale modeling is a powerful approach to obtain macroscopic transport properties of porous media, which are traditionally obtained from experiments and understand the relationship between fluid dynamics with complex pore geometries. In image-based modeling, flow simulations are conducted based on pore structures of real porous media from X-ray computed tomographic images. Rigorous pore-scale finite element modeling using unstructured …
Continuous Reservoir Modeling Updating By Integrating Experimental Data Using An Ensemble Kalman Filter, Ting Sun
LSU Doctoral Dissertations
The continuous researvoir model updating is widely used to calibrate reservoir simulation models to production data, but many challenges remain. First, few real field data are available to test the new history matching method, and most of the data sets are synthetic cases. Second, computational cost may be high when using non-Gaussian priors or nonlinear models. Third, with large complex models, the simulation runs and history matching method require huge memory allocations. This dissertation achieves a continuous reservoir model updating workflow with a meter-scale , two-phase flow experiment. Both production and seismic data are collected in the experiment. Because the …
Analysis Of Hydrodynamic Drag Forces Acting On Suspended Fine Particle In Porous Media, Seyed Amin Mirsaeidi Farahani
Analysis Of Hydrodynamic Drag Forces Acting On Suspended Fine Particle In Porous Media, Seyed Amin Mirsaeidi Farahani
LSU Doctoral Dissertations
An important class of flow and transport problems occurring in porous media involves the interactions between suspended fine particles and the moving fluid at Stokes limit. Historically, due to the complicated geometries of porous media, researchers have had to resort to simplifying assumptions to conceptualize the underlying physics. However, the advent of high performance computing, in recent decades, has made it possible to vigorously investigate this problem at the streamline scale level. In this work, the flow problem is solved by means of a finite-element model. The simulations results are used to compute the drag forces experienced by suspended fine …
Development Of Remote Sensing Assisted Water Quality Nowcasting And Forecasting Models For Coastal Beaches, Zaihong Zhang
Development Of Remote Sensing Assisted Water Quality Nowcasting And Forecasting Models For Coastal Beaches, Zaihong Zhang
LSU Doctoral Dissertations
A remote sensing assisted water quality modeling framework is developed in this dissertation for nowcasting and forecasting recreational water quality of Holly Beach in Louisiana, USA. The modeling framework is composed of four models/systems: (1) an Artificial Neural Network (ANN) model (Model 1) and an US EPA Virtual Beach (VB) Program-based model for predicting early morning enterococci (ENT) levels in beach waters; (2) an ANN model (Model 2) and an VB model for predicting early morning Fecal Coliform (FC) levels in beach waters; (3) a remote sensing assisted modeling system (Model 3) for predicting near real time ENT levels during …
Innovative Heat Transfer Augmentation Techniques In Mechanical Face Seal, Nian Xiao
Innovative Heat Transfer Augmentation Techniques In Mechanical Face Seal, Nian Xiao
LSU Doctoral Dissertations
Excessive heat generated at the face seal contact interface has been recognized as one of main causes of failure of mechanical seals. In the past few decades various efforts have been attempted to remove heat from the contact interface uniformly in order to reduce the interfacial temperature, eliminate thermally-induced failure, and thus increase the life of a mechanical seal. Two innovative heat transfer augmentation techniques - surface texturing and built-in phase change device - have been developed in our laboratory to effectively enhance the heat transfer in mechanical face seal. Surface texturing can increase the surface area, change the near …
Applications Of Cfd Simulations On Studying The Multiphase Flow In Microfluidic Devices, Yuehao Li
Applications Of Cfd Simulations On Studying The Multiphase Flow In Microfluidic Devices, Yuehao Li
LSU Doctoral Dissertations
Microfluidics has been extensively investigated as a unique platform to synthesize nanoparticles with desired properties, e.g., size and morphology. Compared to the conventional batch reactors, wet-chemical synthesis using continuous flow microfluidics provides better control over addition of reagents, heat and mass transfer, and reproducibility. Recently, millifluidics has emerged as an alternative since it offers similar control as microfluidics. With its dimensions scaled up to millimeter size, millifluidics saves fabrication efforts and potentially paves the way for industrial applications. Good designs and manipulations of microfluidic and millifluidic devices rely on solid understanding of fluid dynamics. Fluid flow plays an important role …
Energy Dissipation And Entropy Generation During The Fatigue Degradation: Application To Health Monitoring Of Composites, Ali Kahirdeh
Energy Dissipation And Entropy Generation During The Fatigue Degradation: Application To Health Monitoring Of Composites, Ali Kahirdeh
LSU Doctoral Dissertations
In this dissertation, an experimental approach for characterizing energy dissipation and degradation evolution in a woven Epoxy/Glass (G10/FR4) laminate subjected to fully reversed bending fatigue test is presented. Infrared thermography and acoustic emission are utilized to characterize the degradation progression. The results show similar evolutionary response indicating the presence of three degradation stages. The effect of the surface cooling on the fatigue life of the laminates is investigated both experimentally and analytically. The results show that the life of the laminate is highly dependent on the temperature and that surface cooling can significantly increase the fatigue life of the laminate. …