Mechanical Engineering Commons^™

Host-Guest Interaction Dictated Selective Adsorption And Fluorescence Quenching Of A Luminescent Lightweight Metal-Organic Framework Toward Liquid Explosives, Dan Liu, Xiaojuan Liu, Yongxin Liu, Yang Yu, Fanglin Chen, Cheng Wang

Faculty Publications

In this article, we report the successful preparation of a Mg-based luminescent MIL-53 metal–organic framework (MOF), namely [Mg2(BDC)2(BPNO)]·2DMF (1) (BDC = 1,4-benzene dicarboxylate, BPNO = 4,4’- dipyridyl-N,N’-dioxide, DMF = N,N-dimethylformamide) in a mixed solvent containing a 2 : 3 volume ratio of DMF and ethanol (EtOH) under solvothermal conditions. Desolvated compound 1a can be used as an absorbent for selective adsorption and separation of liquid explosives, including nitroaromatic (nitrobenzene (NB)) and nitroaliphatic (nitromethane (NM) and nitroethane (NE)) compounds, through single crystal-to-single crystal (SC–SC) transformations. As one of the weakly luminescent MOFs, the luminescence of compound 1a could be quenched by …

Ultrasonics Transduction In Metallic And Composite Structures For Structural Health Monitoring Using Extensional And Shear Horizontal Piezoelectric Wafer Active Sensors, Ayman Kamal Abdelrahman

Theses and Dissertations

Structural health monitoring (SHM) is crucial for monitoring structures performance, detecting the initiation of flaws and damages, and predicting structural life span. The dissertation emphasizes on developing analytical and numerical models for ultrasonics transduction between piezoelectric wafer active sensors (PWAS), and metallic and composite structures.

The first objective of this research is studying the power and energy transduction between PWAS and structure for the aim of optimizing guided waves mode tuning and PWAS electromechanical (E/M) impedance for power-efficient SHM systems. Analytical models for power and energy were developed based on exact Lamb wave solution with application on multimodal Lamb wave …

Thermal Analysis Of High Pressure Micro Plasma Discharge, Mostafa Mobli

Theses and Dissertations

High pressure micro plasma discharge has been at the center of interest in recent years, because of their vast applications, ease of access and cost efficiency. This attributes to atmospheric discharges that are generated in ambient conditions and therefore can be readily applicable to everyday use. The absence of vacuum makes these high pressure discharges to be inexpensive to operate. Despite the ease of operation, the high pressure is a source of enhanced gas heating as the gas temperature cannot be controlled by diffusion alone. Gas heating is therefore an important factor when it comes to the simulation of high …

Oxygen Flux And Dielectric Response Study Of Mixed Ionic-Electronic Conducting (Miec) Heterogeneous Functional Materials, Fazle Rabbi

Theses and Dissertations

Dense mixed ionic-electronic conducting (MIEC) membranes consisting of ionic conductive perovskite-type and/or fluorite-type oxides and high electronic conductive spinel type oxides, at elevated temperature can play a useful role in a number of energy conversion related systems including the solid oxide fuel cell (SOFC), oxygen separation and permeation membranes, partial oxidization membrane reactors for natural gas processing, high temperature electrolysis cells, and others. This study will investigate the impact of different heterogeneous characteristics of dual phase ionic and electronic conductive oxygen separation membranes on their transport mechanisms, in an attempt to develop a foundation for the rational design of such …

Investigation Of Thermal Performance Of Nanoparticle Enhanced Ionic Liquids (Neils) For Solar Collector Applications, Titan Chandra Paul

Theses and Dissertations

Concentrated Solar Power (CSP) is a prominent alternative energy technology, where mirrors or lenses are used to concentrate sunlight from a large area and stored in a collector filled with heat transfer fluid (HTF). The energy from this HTF is used to produce steam for power generation. CSP system requires high heat storage capacity and thermally stable HTF to reduce its operating cost. Having suitable thermophysical properties, ionic liquids (ILs) is considered as a potential HTF for the CSP applications; however thermophysical properties of ILs can be further enhanced by dispersing small volume percentages of nanoparticles. This liquid is called …

Structural Health Monitoring Using Linear And Nonlinear Ultrasonic Guided Waves, Yanfeng Shen

Theses and Dissertations

The dissertation addresses Structural Health Monitoring (SHM) using linear and nonlinear ultrasonic guided waves, with an emphasis on the development of analytical and numerical models of guided wave propagation and interaction with linear and nonlinear structural damage.

An analytical model was developed based on the exact Lamb wave solution for the simulation of Lamb wave propagation and interaction with damage. The damage effects were inserted into the model using complex valued wave damage interaction coefficients (WDICs). The analytical procedure was coded as a framework into a MATLAB Graphical User Interface (GUI), and the software WaveFormRevealer (WFR) was developed as a …

Plant-Biomimetic Hydrogel Actuators: Creating Movement In Hydrogels Through The Study Of Plants, Christen Rhodes

Theses and Dissertations

Plants are sessile organisms that have developed methods of movement to respond to environmental stimuli. Some of the approaches feature the unequal expansion of cells and controlling deformation direction through fibers under swelling and drying. Hydrogels are three dimensional polymer networks that have the capacity for large volume changes due their affinity for water and can be tough and/or stimuli-responsive. In this paper, three preliminary plant-biomimetic hydrogel actuator designs are discussed and tested from wet to dry. The first actuator design, termed a 1%-0.1% bilayer, features two layers of different swelling and drying rates due to differences in cross-linking density. …

Dielectric Properties Of Composite Materials During Damage Accumulation And Fracture, Md. Rassel Raihan

Theses and Dissertations

Fiber reinforced polymer matrix composite materials have many unique properties and their high performance makes them available to use in many advanced technologies i.e. aerospace, microelectronics, and energy storage. There is a correlation that exists between the long term behavior of those materials under combined mechanical, thermal, and electrical fields, and the functional properties and characteristics of the composite materials that requires a fundamental understanding of the material state changes caused by deformation and damage accumulation. This will ultimately lead, for example, to the design and synthesis of optimal multifunctional material systems. Composite materials are heterogeneous and the complex morphology …

Performance And Durability Of Electrodes With Platinum Catalysts In Polymer Electrolyte Cells Prepared By Ultrasonic Spray Deposition, William A. Rigdon

Theses and Dissertations

Catalysts in the electrodes of polymer electrolyte cells serve a critical function in reactions which can be used to either generate electrical energy from chemical fuels or convert electrical energy into chemicals. For low temperature electrochemical fuel cells, platinum is often utilized for its exceptional catalytic activities towards hydrogen oxidation and oxygen reduction reactions of the anode and cathode, respectively. However, the limited supply of platinum and high demand result in prohibitive costs plaguing commercialization of this technology. Therefore, minimal amounts of the catalyst should be used to achieve the maximum output to reduce expenses. Electrochemical behavior is governed by …

Phonon Confinement Using Spirally Designed Elastic Resonators In Discrete Continuum, Sourav Banerjee, Raiz U. Ahmed

Faculty Publications

Periodic and chiral orientation of microstructures, here we call phononic crystals, have extraordinary capabilities to facilitate the innovative design of new generation metamaterials. Periodic arrangements of phononic crystals are capable of opening portals of non-passing, non-dispersive mechanical waves. Defying conventional design of regular periodicity, in this paper spirally periodic but chiral orientation of resonators are envisioned. Dynamics of the spirally connected resonators and the acoustic wave propagation through the spirally connected multiple local resonators are studied using fundamental physics. In present study the spiral systems with local resonators are assumed to be discrete media immersed in fluid. In this paper …

Uncertainty Quantification Driven Predictive Multi-Scale Model For Synthesis Of Mycotoxins, Sourav Banerjee, Gabriel A. Terejanu, Anindya Chanda

Faculty Publications

Many toxic molds synthesize and release an array of poisons, termed mycotoxins that have an enormous impact on human health, agriculture and economy [1]. These molds contaminate our buildings, indoor air and crops, cause life threatening human and animal diseases and reduce agricultural output [2]. In order to design appropriate approaches to minimize the detrimental effects of these fungi, it is essential to develop diagnostic methodologies that can rapidly and accurately determine based on fungal strains and their growth patterns, the extent of mycotoxin mediated damage caused to the environment.Here we developed a novel multi-scale predictive mathematical model that could …

Redox Stable Anodes For Solid Oxide Fuel Cells, Guoliang Xiao, Fanglin Chen

Faculty Publications

Solid oxide fuel cells (SOFCs) can convert chemical energy from the fuel directly to electrical energy with high efficiency and fuel flexibility. Ni-based cermets have been the most widely adopted anode for SOFCs. However, the conventional Ni-based anode has low tolerance to sulfur-contamination, is vulnerable to deactivation by carbon build-up (coking) from direct oxidation of hydrocarbon fuels, and suffers volume instability upon redox cycling. Among these limitations, the redox instability of the anode is particularly important and has been intensively studied since the SOFC anode may experience redox cycling during fuel cell operations even with the ideal pure hydrogen as …

Probing The Roles Of Polymeric Separators In Lithium-Ion Battery Capacity Fade At Elevated Temperatures, Jianchao Chen, Yongda Yan, Tao Sun, Yue Qi, Xiaodong Li

Faculty Publications

The high temperature mechanical property of separators is very important for safety of lithium-ion batteries. However, the mechanical integrity of polymeric separators in lithium-ion batteries at elevated temperatures is still not well characterized. In this paper, the temperature dependent micro-scale morphology change of PP (polypropylene)-PE (polyethylene)-PP sandwiched separators (Celgard 2325) was studied by in-situ high temperature surface imaging using an atomic force microscope (AFM) coupled with power spectral density (PSD) analysis and digital image correlation (DIC) technique. Both PSD and DIC analysis results show that the PP phase significantly closes its pores by means of dilation of the nanofibrils surrounding …

A Novel Intermediate-Temperature All Ceramic Iron–Air Redox Battery: The Effect Of Current Density And Cycle Duration, Xuan Zhao, Xue Li, Yunhui Gong, Nansheng Xu, Kevin Huang

Faculty Publications

We here report the energy storage characteristics of a new all ceramic iron–air redox battery comprising of a reversible solid oxide fuel cell as the charger/discharger and a Fe–FeO_x redox couple as the chemical storage bed. The effects of current density and cycle duration on specific energy and round trip efficiency of the new battery have been systematically studied at 650°C and 550°C. The results explicitly show that current density is the most influential variable on the performance, signifying the importance of improving electrochemical performance of the reversible solid oxide fuel cell.

Handloaded Rifle Ammunition: A Look Into The Assembly Process, Load Development Methods, And Its Comparison To Factory Ammunition, Jeffrey Dalton Snyder

Senior Theses

The purpose of this thesis is to educate the reader on the appeal of assembling firearm ammunition from its individual components, a process known as “handloading,” in comparison to factory assembled ammunition. This is accomplished by providing the reader with the benefits of handloading with an overview of the handloading process. Then, an example of a handload development method (Ladder Test) is discussed and performed. The results from the test are then analyzed and explained. Finally, the handloaded ammunition from the test is compared by function and price to factory ammunition from three different market segments.

The project portion of …

Characterization Of 3d Interconnected Microstructural Network In Mixed Ionic And Electronic Conducting Ceramic Composites, William M. Harris, Kyle S. Brinkman, Ye Lin, Dong Su, Alex P. Cocco, Arata Nakajo, Matthew B. Degostin, Yu-Chen Karen Chen-Wiegart, Jun Wang, Fanglin Chen, Yong S. Chu, Wilson K. S. Chiu

Faculty Publications

The microstructure and connectivity of the ionic and electronic conductive phases in composite ceramic membranes are directly related to device performance. Transmission electron microscopy (TEM) including chemical mapping combined with X-ray nanotomography (XNT) have been used to characterize the composition and 3-D microstructure of a MIEC composite model system consisting of a Ce_0.8Gd_0.2O₂ (GDC) oxygen ion conductive phase and a CoFe₂O₄ (CFO) electronic conductive phase. The microstructural data is discussed, including the composition and distribution of an emergent phase which takes the form of isolated and distinct regions. Performance implications are considered …

A Sinteractive Ni-Bazr0.8Y0.2O3-Δ Composite Membrane For Hydrogen Separation, Shumin Fang, Siwei Wang, Kyle S. Brinkman, Fanglin Chen

Faculty Publications

BaZr_0.8Y_0.2O_3−δ (BZY) is an excellent candidate material for hydrogen permeation membranes due to its high bulk proton conductivity, mechanical robustness, and chemical stability in H₂O- and CO₂-containing environments. Unfortunately, the use of BZY as a separation membrane has been greatly restrained by its highly refractory nature, poor grain boundary proton conductivity, high number of grain boundaries resulting from limited grain growth during sintering, as well as low electronic conductivity. These problems can be resolved by the fabrication of a Ni–BZY composite membrane with large BZY grains, which requires the development …

Investigation Of The High-Temperature Redox Chemistry Of Sr2Fe1.5Mo0.5O6-Δ Via In Situ Neutron Diffraction, Daniel E. Bugaris, Jason P. Hodges, Ashfia Hug, W. Michael Chance, Andreas Heyden, Fanglin Chen, Hans-Conrad Zur Loye

Faculty Publications

Crystallographic structural changes were investigated for Sr₂Fe_1.5Mo_0.5O_6−δ, an electrode material for symmetric solid oxide fuel cells. The samples of this material were heated and cooled in wet hydrogen and wet oxygen atmospheres, to simulate the reducing and oxidizing conditions experienced under actual fuel cell operating conditions, and their structures and oxygen contents were determined using in situ powder neutron diffraction. The existence of a reversible tetragonal to cubic phase transition was established to occur between room temperature and 400 °C, both on heating and cooling in either oxygen or hydrogen. The …

Sr3<−3xNa3xSi3O9−1.5x (X = 0.45) As A Superior Solid Oxide-Ion Electrolyte For Intermediate Temperature-Solid Oxide Fuel Cells, Tao Wei, Preetam Singh, Yunhui Gong, John B. Goodenough, Yunhui Huang, Kevin Huang

Faculty Publications

We here report that a newly discovered superior oxide-ion conductor Sr_3−3xNa_3xSi₃O_9−1.5x (x = 0.45) (SNS) demonstrates full potential to be a practical solid electrolyte for intermediate temperature-solid oxide fuel cells (IT-SOFCs). It exhibits the highest oxide-ion conductivity with the lowest activation energy among all the chemically stable solid oxide-ion conductors reported. The ionic conductivity is stable over a broad range of partial pressures of oxygen (10⁻³⁰ to 1 atm) for an extended period of time. A SOFC based on a 294 μm thick SNS-electrolyte produces peak power densities …

Modeling Of Chemical-Mechanical Couplings In Anode-Supported Solid Oxide Fuel Cells And Reliability Analysis, Xinfang Jin, Xingjian Xue

Faculty Publications

Oxygen ionic transport in conducting ceramics is an important mechanism enabling solid oxide fuel cell (SOFC) technology. The multi-physicochemical processes lead to the fact that the distribution of oxygen vacancy site fraction is not uniform in a positive-electrode electrolyte negative-electrode (PEN) assembly. Different oxygen vacancy concentrations induce different volumetric expansion of ceramics, resulting in complicated chemical–mechanical coupling phenomena and chemical stress in SOFCs. In this research, a mathematical model is developed to study oxygen ionic transport induced chemical stress in an SOFC. The model is validated using experimental polarization curves. Comprehensive simulations are performed to investigate chemical stress distribution in …

Material Synthesis And Fabrication Method Development For Intermediate Temperature Solid Oxide Fuel Cells, Hanping Ding

Theses and Dissertations

Solid oxide fuel cells (SOFCs) are operated in high temperature conditions (750-1000 oC). The high operating temperature in turn may lead to very complicated material degradation issues, significantly increasing the cost and reducing the durability of SOFC material systems. In order to widen material selections, reduce cost, and increase durability of SOFCs, there is a growing interest to develop intermediate temperature SOFCs (500-750 oC). However, lowering operating temperature will cause substantial increases of ohmic resistance of electrolyte and polarization resistance of electrodes. This dissertation aimed at developing high-performance intermediate-temperature SOFCs through the employment of a series of layered perovskite oxides …

Classification Of Low Velocity Impactors Using Spiral Sensing Of Acousto-Ultrasonic Waves, Chijioke Agbasi

Theses and Dissertations

The non-linear elastodynamics of a flat plate subjected to low velocity foreign body impacts is studied, resembling the space debris impacts on the space structure. The work is based on a central hypothesis that in addition to identifying the impact locations, the material properties of the foreign objects can also be classified using acousto-ultrasonic signals (AUS). Simultaneous localization of impact point and classification of impact object is quite challenging using existing state-of-the-art structural health monitoring (SHM) approaches. Available techniques seek to report the exact location of impact on the structure, however, the reported information is likely to have errors from …

Heat Transfer Enhancement By Three-Dimensional Surface Roughness Technique In Nuclear Fuel Rod Bundles, Kang Liu

Theses and Dissertations

DISS_abstract> This thesis investigate thermal characteristic of a single-phase nano-fluid in a single heater element loop tester and provides a comparison between heat transfer enhancement results achieved using water as a coolant and using nano-fluids with different volume percentage. The experimental investigation is performed on two simulated nuclear fuel rods with two different types of modified outer surfaces roughness. The fuel rod surfaces modified are termed as two-dimensional surface roughness (square transverse ribbed surface) and three-dimensional surface roughness (Diamond shaped blocks). The nano-fluid used are 0.5% and 2% ZnO-Deionized water based nano-fluid. The maximum heat transfer co-efficient enhancement achieved compared …

Measuring The Effectiveness Of Education For Sustainable Development Interventions For Effecting Change In Knowledge, Attitude And Behaviors Toward Sustainable Development, Christopher Robin Wilson

Theses and Dissertations

The question addressed by this study is whether an intervention involving a brief, focused seminar providing Sustainability Fundamental education can affect change in sustainability-centric behavior via measured change in attitude toward sustainability and/or change knowledge of sustainability fundamentals.

This study focused on applying and extending lessons from a previous exploration of the relationships between sustainable behavior and both attitude toward sustainability and knowledge of sustainability. The test involved determining whether brief, science-based sustainability fundamentals seminars are an effective intervention for affecting the favorable sustainable behavior of practicing engineers, defined as professionals engaged in engineering post-completion of their formal studies, in …

Influence Of Crystal Structure On The Electrochemical Performance Of A-Site-Deficient Sr1-SNb0.1Co0.9O3-Δ Perovskite Cathodes, Yinlong Zhu, Ye Lin, Xuan Shen, Jaka Sunarso, Wei Zhou, Shanshan Jiang, Dong Su, Fanglin Chen, Zongping Shao

Faculty Publications

The creation of A-site cation defects within a perovskite oxide can substantially alter the structure and properties of its stoichiometric analogue. In this work, we demonstrate that by vacating 2 and 5% of Asite cations from SrNb_0.1Co_0.9O_3-δ (SNC1.00) perovskites (Sr_1-sNb_0.1Co_0.9O_3-δ,s = 0.02 and 0.05; denoted as SNC0.98 and SNC0.95, respectively), a Jahn–Teller (JT) distortion with varying extents takes place, leading to the formation of a modified crystal lattice within a the perovskite framework. Electrical conductivity, electrochemical performance, chemical compatibility and microstructure of Sr_1-sNb_0.1Co …

Predictive Modeling Of Coupled Multi-Physics Systems: Ii. Illustrative Application To Reactor Physics, Dan Gabriel Cacuci, Madalina Corina Badea

Faculty Publications

This work presents paradigm applications to reactor physics of the innovative mathematical methodology for "predictive modeling of coupled multi-physics systems (PMCMPS)" developed by Cacuci (2014). This methodology enables the assimilation of experimental and computational information and computes optimally predicted responses and model parameters with reduced predicted uncertainties, taking fully into account the coupling terms between the multi-physics systems, but using only the computational resources that would be needed to perform predictive modeling on each system separately. The paradigm examples presented in this work are based on a simple neutron diffusion model, chosen so as to enable closed-form solutions with clear …

A Platinum Nanowire Network As A Highly Effective Current Collector For Intermediate Temperature Solid Oxide Fuel Cells, Hanping Ding, Xingjian Xue

Faculty Publications

We report the fabrication and evaluation of a platinum nanowire network as a highly efficient current collector for solid oxide fuel cells (SOFCs). The ink of carbon-black supported platinum nanoparticles was sprayed onto the cathode. After firing, the carbon black was oxidized and disappeared as carbon dioxide gas while the platinum nanoparticles connect with one another, forming a tree-branch-like nanowire network. The diameters of the nanowires range from 100 nm to 400 nm. Compared to a conventional platinum paste current collector, the polarization resistance of the PrBaCo₂O_5+δ (PBCO) cathode with a nanowire current collector was reduced …

Modeling Of Chemical-Mechanical Couplings In Solid Oxide Cells And Reliability Analysis, Xinfang Jin

Theses and Dissertations

Solid oxide fuel cell (SOFC) has been well demonstrated as a promising clean energy conversion technology. For practical applications, the SOFC systems should have both good electrochemical performance and high reliability. The SOFCs are usually operated under very aggressive conditions, e.g., high temperatures (600-1000oC) and extremely low oxygen partial pressures (anode electrode). These aggressive operating conditions could lead to a variety of material system degradations, imposing great challenges on meeting lifetime requirement of SOFC commercial applications. It is therefore essential to increase the understanding of fundamental SOFC degradation mechanisms.

The basic structure of SOFCs is a positive electrode-electrolyte-negative electrode (PEN) …

Low Frequency Energy Scavenging Using Sub-Wave Length Scale Acousto-Elastic Metamaterial, Raiz U. Ahmed, Sourav Banerjee

Faculty Publications

This letter presents the possibility of energy scavenging (ES) utilizing the physics of acousto-elastic metamaterial (AEMM) at low frequencies (<∼3KHz). It is proposed to use the AEMM in a dual mode (Acoustic Filter and Energy Harvester), simultaneously. AEMM’s are typically reported for filtering acoustic waves by trapping or guiding the acoustic energy, whereas this letter shows that the dynamic energy trapped inside the soft constituent (matrix) ofmetamaterials can be significantly harvested by strategically embedding piezoelectric wafers in the matrix. With unit cell AEMM model, we experimentally asserted that at lower acoustic frequencies (< ∼3 KHz), maximum power in the micro Watts (∼35µW) range can be generated, whereas, recently reported phononic crystal based metamaterials harvested only nano Watt (∼30nW) power against 10KΩ resistive load. Efficient energy scavengers at low acoustic frequencies are almost absent due to large required size relevant to the acoustic wavelength. Here we report sub wave length scale energy scavengers utilizing the coupled physics of local, structural and matrix resonances. Upon validation of the argument through analytical, numerical and experimental studies, a multi-frequency energy scavenger (ES) with multi-cellmodel is designed with varying geometrical properties capable of scavenging energy (power output from ∼10µW – ∼90µW) between 0.2 KHz and 1.5 KHz acoustic frequencies.

Ni-Doped Sr2Fe1.5Mo0.5O6-Δ As Anode Materials For Solid Oxide Fuel Cells, Guoliang Xiao, Siwei Wang, Ye Lin, Zhibin Yang, Minfang Han, Fanglin Chen

Faculty Publications

10% Ni-doped Sr₂Fe_1.5Mo_0.5O_6-δ with A-site deficiency is prepared to induce in situ precipitation of B-site metals under anode conditions in solid oxide fuel cells. XRD, SEM and TEM results show that a significant amount of nano-sized Ni-Fe alloy metal phase has precipitated out from Sr_1.9Fe_1.4Ni_0.1Mo_0.5O_6-δ upon reduction at 800^◦C in H₂. The conductivity of the reduced composite reaches 29 S cm⁻¹ at 800^◦C in H₂. Furthermore, fuel cell performance of the composite anode Sr_{1.9 …}