Mechanical Engineering Commons^™

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 …

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 …

There Can Be Turbulence In Microfluidics At Low Reynolds Number, Guiren Wang, F. Yang, Wei Zhao

Faculty Publications

Turbulence is commonly viewed as a type of macroflow, where the Reynolds number (Re) has to be sufficiently high. In microfluidics, when Re is below or on the order of 1 and fast mixing is required, so far only chaotic flow has been reported to enhance mixing based on previous publications since turbulence is believed not to be possible to generate in such a low Re microflow. There is even a lack of velocimeter that can measure turbulence in microchannels. In this work, we report a direct observation of the existence of turbulence in microfluidics with Re on the order …

Design, Fabrication, And Properties Of 2-2 Connectivity Cement/Polymer Based Piezoelectric Composites With Varied Piezoelectric Phase Distribution, Xu Dongyu, Cheng Xin, Sourav Banerjee, Huang Shifeng

Faculty Publications

The laminated 2-2 connectivity cement/polymer based piezoelectric composites with variedpiezoelectric phase distribution were fabricated by employing Lead Zirconium Titanate ceramicas active phase, and mixture of cement powder, epoxy resin, and hardener as matrix phase with a mass proportion of 4:4:1. The dielectric, piezoelectric, and electromechanical coupling properties of the composites were studied. The composites with large total volume fraction ofpiezoelectric phase have large piezoelectric strain constant and relative permittivity, and thepiezoelectric and dielectric properties of the composites are independent of the dimensional variations of the piezoelectric ceramic layer. The composites with small total volume fraction of piezoelectric phase have large …

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 …}

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 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 …

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 …

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 …

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) …

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 …

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 …

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 …

Promoting Electrocatalytic Activity Of A Composite Sofc Cathode La0.8Sr0.2Mno3+Δ/Ce0.8Gd0.2O2-Δ With Molten Carbonates, Yunhui Gong, Xue Li, Lingling Zhang, Whitney Tharp, Changyong Qin, Kevin Huang

Faculty Publications

The effect of molten carbonates (MCs) on polarization resistance (R_P), a direct measure of oxygen reduction reaction (ORR) activity, of a composite La_0.8Sr_0.2MnO_3+δ/Ce_0.8Gd_0.2O_2-δ (LSM/GDC) solid oxide fuel cell (SOFC) cathode has been systematically investigated in this study over a temperature range of 550–650°C and partial pressure of oxygen (pO₂) span of 10⁻³ ∼ 1 atm. It is shown that the LSM/GDC cathode, either in the pristine or MC-modified states, can be generally modeled by two consecutive parallel circuits consisting of a resistance and a …

Fundamental Experimental Studies In Scaling, Blast Mitigation And Material Processing, Xing Zhao

Theses and Dissertations

In this work, two separate research efforts are discussed. They include experimental studies in (1) Scaling and Blast Mitigation and (2) Scaling in Friction Stir Extrusion. In both studies, the primary experimental measurement method is three-dimensional digital image correlation (3D-DIC), a non-contacting full-field measurement method that is applicable for both high-rate loading and quasi-static loading conditions.

Scaling and Blast Mitigation Studies:

A series of properly scaled structures was subjected to buried blast loading conditions via detonation of a small explosive buried in saturated sand. Using high speed stereo-vision systems to record the deformations of selected regions on the upper surface …

Enhanced Reversibility And Durability Of A Solid Oxide Fe–Air Redox Battery By Carbothermic Reaction Derived Energy Storage Materials, Xuan Zhao, Xue Li, Yunhui Gong, Kevin Huang

Faculty Publications

The recently developed solid oxide metal–air redox battery is a new technology capable of high-rate chemistry. Here we report that the performance, reversibility and stability of a solid oxide iron–air redox battery can be significantly improved by nanostructuring energy storage materials from a carbothermic reaction.

A New Solid Oxide Molybdenum–Air Redox Battery, Xuan Zhao, Yunhui Gong, Xue Li, Nansheng Xu, Kevin Huang

Faculty Publications

A new type of rechargeable molybdenum–air battery based on the technologies of reversible solid oxide fuel cells and chemical looping is reported in this study. The reversible solid oxide fuel cell serves as the electrical unit to realize the charging and discharging cycles while a pair of Mo/MoO2 redox couple integrated with the reversible solid oxide fuel cell stores electrical energy via an H2–H2O oxygen shuttle. The specific charge of the new battery reaches 1117 A h per kg-Mo at 550°C, which is 45% higher than the non-rechargeable Mo–air battery. The corresponding discharge specific energy is 974 W h per …

Enhanced Reducibility And Conductivity Of Na/K-Doped Srti0.8Nb0.2O3, Guoliang Xiao, Sirikanda Nuansaeng, Lei Zhang, Suwit Suthirakun, Andreas Heyden, Hans-Conrad Zur Loye, Fanglin Chen

Faculty Publications

Donor and acceptor co-doped SrTiO₃ materials have shown interesting features in their conductivity and reducibility. In this work, 10 mol% Na⁺ or K⁺ as acceptor dopants have been introduced into the A-site of donor-doped strontium titanate, SrTi_0.8Nb_0.2O₃, and the doping impact on their properties has been studied. By doping with Na or K, the sinterability of SrTi_0.8Nb_0.2O₃ in reducing atmospheres has been improved. Na_0.1Sr_0.9Ti_0.8Nb_0.2O₃ and K_0.1Sr_0.9Ti_0.8Nb_0.2O₃ show metallic …

Cyclic Durability Of A Solid Oxide Fe-Air Redox Battery Operated At 650°C, Xuan Zhao, Yunhui Gong, Xue Li, Nansheng Xu, Kevin Huang

Faculty Publications

The recently developed rechargeable solid oxide metal-air redox battery has shown a great potential for applications in mid- to large-scale stationary energy storage. Cyclic durability is one of the most important requirements for stationary energy storage. In this study, we report the cyclic durability of a solid oxide Fe-air redox battery operated at 650°C. The battery was continuously cycled 100 times under a current density of 50 mA/cm² with rather flat performance, producing an average specific energy of 760 Wh/kg-Fe at a round-trip efficiency of 55.5%. The post-test examination indicated that the performance losses could arise from the fuel-electrode …

Cyclic Durability Of A Solid Oxide Fe-Air Redox Battery Operated At 650°C, Xuan Zhao, Yunhui Gong, Xue Li, Nansheng Xu, Kevin Huang

Faculty Publications

The recently developed rechargeable solid oxide metal-air redox battery has shown a great potential for applications in mid- to large-scale stationary energy storage. Cyclic durability is one of the most important requirements for stationary energy storage. In this study, we report the cyclic durability of a solid oxide Fe-air redox battery operated at 650◦C. The battery was continuously cycled 100 times under a current density of 50 mA/cm2 with rather flat performance, producing an average specific energy of 760 Wh/kg-Fe at a round-trip efficiency of 55.5%. The post-test examination indicated that the performance losses could arise from the fuel-electrode of …

Computer Vision Based, Non-Contacting Deformation And Shape Measurements: A Revolution In Progress, Michael A. Sutton

Journal of the South Carolina Academy of Science

The rapid expansion of computer technology in the past thirty years has impacted society in innumerable ways. Of interest for this discussion is the breath-taking change in measurement sciences that has occurred as the digital age dawned and has now become part of our daily lives. In particular, the effect on image-based, non-contacting measurements will be described and the continuing revolutionary impact that the resulting technology has engendered will be reviewed. Additionally, the unprecedented expansion of capabilities will be highlighted by presenting a set of illustrative example studies.