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University of South Carolina

Faculty Publications

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2016

Articles 1 - 11 of 11

Full-Text Articles in Engineering

Predictive Modeling Of A Buoyancy-Operated Cooling Tower Under Unsaturated Conditions: Adjoint Sensitivity Model And Optimal Best-Estimate Results With Reduced Predicted Uncertainties, Federico Di Rocco, Dan Gabriel Cacuci Dec 2016

Predictive Modeling Of A Buoyancy-Operated Cooling Tower Under Unsaturated Conditions: Adjoint Sensitivity Model And Optimal Best-Estimate Results With Reduced Predicted Uncertainties, Federico Di Rocco, Dan Gabriel Cacuci

Faculty Publications

Nuclear and other large-scale energy-producing plants must include systems that guarantee the safe discharge of residual heat from the industrial process into the atmosphere. This function is usually performed by one or several cooling towers. The amount of heat released by a cooling tower into the external environment can be quantified by using a numerical simulation model of the physical processes occurring in the respective tower, augmented by experimentally measured data that accounts for external conditions such as outlet air temperature, outlet water temperature, and outlet air relative humidity. The model’s responses of interest depend on many model parameters including …

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Fabrication Of High Performing Pemfc Catalyst-Coated Membranes With A Low Cost Air-Assisted Cylindrical Liquid Jets Spraying System, Xiong Peng, Travis Omasta, William Rigdon, William E. Mustain Nov 2016

Fabrication Of High Performing Pemfc Catalyst-Coated Membranes With A Low Cost Air-Assisted Cylindrical Liquid Jets Spraying System, Xiong Peng, Travis Omasta, William Rigdon, William E. Mustain

Faculty Publications

In this work, a low cost air-assisted cylindrical liquid jets spraying (ACLJS) system was developed to prepare high-performance catalyst-coated membranes (CCMs) for proton exchange membrane fuel cells (PEMFCs). The catalyst ink was flowed from a cylindrical orifice and was atomized by an air stream fed from a coaxial slit and sprayed directly onto the membrane, which was suctioned to a heated aluminum vacuum plate. The CCM pore architecture including size, distribution and volume can be controlled using various flow parameters, and the impact of spraying conditions on electrode structure and PEMFC performance was investigated. CCMs fabricated in the fiber-type break-up …

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Investigation Of Shadowing Effects In Typical Propagation Scenarios For High Speed Railway At 2350 Mhz, Liu Liu, Cheng Tao, David W. Matolak, Tao Zhou, Houjin Chen Sep 2016

Investigation Of Shadowing Effects In Typical Propagation Scenarios For High Speed Railway At 2350 Mhz, Liu Liu, Cheng Tao, David W. Matolak, Tao Zhou, Houjin Chen

Faculty Publications

Based on realistic measurements in China, shadowing characteristics at the frequency of 2350 MHz were investigated in typical High-Speed Railway environments. After confirming that the measured shadowing satisfies wide-sense stationarity (assessed via the reverse arrangement test method), we quantify the shadowing correlation. Three types of correlation models are compared for the shadowing characterization, and the Normalized Mean Square Error is used to determine the best matching model: a single decaying exponential function. Decorrelation distances were found to be 11.9 m, 17.7 m, and 8.3 m in our three HSR scenarios, respectively. The results should be useful for the evaluation and …

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Predictive Modeling Of A Paradigm Mechanical Cooling Tower Model: Ii. Optimal Best-Estimate Results With Reduced Predicted Uncertainties, Ruixian Fang, Dan Gabriel Cacuci, Madalina Badea Sep 2016

Predictive Modeling Of A Paradigm Mechanical Cooling Tower Model: Ii. Optimal Best-Estimate Results With Reduced Predicted Uncertainties, Ruixian Fang, Dan Gabriel Cacuci, Madalina Badea

Faculty Publications

This work uses the adjoint sensitivity model of the counter-flow cooling tower derived in the accompanying PART I to obtain the expressions and relative numerical rankings of the sensitivities, to all model parameters, of the following model responses: (i) outlet air temperature; (ii) outlet water temperature; (iii) outlet water mass flow rate; and (iv) air outlet relative humidity. These sensitivities are subsequently used within the “predictive modeling for coupled multi-physics systems” (PM_CMPS) methodology to obtain explicit formulas for the predicted optimal nominal values for the model responses and parameters, along with reduced predicted standard deviations for the predicted model parameters …

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Predictive Modeling Of A Paradigm Mechanical Cooling Tower: I. Adjoint Sensitivity Model, Dan Gabriel Cacuci, Ruixian Fang Sep 2016

Predictive Modeling Of A Paradigm Mechanical Cooling Tower: I. Adjoint Sensitivity Model, Dan Gabriel Cacuci, Ruixian Fang

Faculty Publications

Cooling towers discharge waste heat from an industrial process into the atmosphere, and are essential for the functioning of large energy-producing plants, including nuclear reactors. Using a numerical simulation model of the cooling tower together with measurements of outlet air relative humidity, outlet air and water temperatures enables the quantification of the rate of thermal energy dissipation removed from the respective process. The computed quantities depend on many model parameters including correlations, boundary conditions, material properties, etc. Changes in these model parameters will induce changes in the computed quantities of interest (called “model responses”). These changes are quantified by the …

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Using The Gauge Condition To Simplify The Elastodynamic Analysis Of Guided Wave Propagation, Bhuiyan Yeasin Md, Victor Giurgiutiu Sep 2016

Using The Gauge Condition To Simplify The Elastodynamic Analysis Of Guided Wave Propagation, Bhuiyan Yeasin Md, Victor Giurgiutiu

Faculty Publications

In this article, gauge condition in elastodynamics is explored more to revive its potential capability of simplifying wave propagation problems in elastic medium. The inception of gauge condition in elastodynamics happens from the Navier-Lame equations upon application of Helmholtz theorem. In order to solve the elastic wave problems by potential function approach, the gauge condition provides the necessary conditions for the potential functions. The gauge condition may be considered as the superposition of the separate gauge conditions of Lamb waves and shear horizontal (SH) guided waves respectively, and thus, it may be resolved into corresponding gauges of Lamb waves and …

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Guided Wave Based Crack Detection In The Rivet Hole Using Global Analytical With Local Fem Approach, Bhuiyan Yeasin Md, Yanfeng Shen, Victor Giurgiutiu Jul 2016

Guided Wave Based Crack Detection In The Rivet Hole Using Global Analytical With Local Fem Approach, Bhuiyan Yeasin Md, Yanfeng Shen, Victor Giurgiutiu

Faculty Publications

In this article, ultrasonic guided wave propagation and interaction with the rivet hole cracks has been formulated using closed-form analytical solution while the local damage interaction, scattering, and mode conversion have been obtained from finite element analysis. The rivet hole cracks (damage) in the plate structure gives rise to the non-axisymmetric scattering of Lamb wave, as well as shear horizontal (SH) wave, although the incident Lamb wave source (primary source) is axisymmetric. The damage in the plate acts as a non-axisymmetric secondary source of Lamb wave and SH wave. The scattering of Lamb and SH waves are captured using wave …

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Recognition Of Smoking Gesture Using Smart Watch Technology, Casey A. Cole, Bethany Janos, Dien Anshari, James Thrasher, Scott Strayer, Homayoun Valafar Jul 2016

Recognition Of Smoking Gesture Using Smart Watch Technology, Casey A. Cole, Bethany Janos, Dien Anshari, James Thrasher, Scott Strayer, Homayoun Valafar

Faculty Publications

Diseases resulting from prolonged smoking are the most common preventable causes of death in the world today. In this report we investigate the success of utilizing accelerometer sensors in smart watches to identify smoking gestures. Early identification of smoking gestures can help to initiate the appropriate intervention method and prevent relapses in smoking. Our experiments indicate 85%-95% success rates in identification of smoking gesture among other similar gestures using Artificial Neural Networks (ANNs). Our investigations concluded that information obtained from the x-dimension of accelerometers is the best means of identifying the smoking gesture, while y and z dimensions are helpful …

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Highly Conductive In-Sno2/Rgo Nano-Heterostructures With Improved Lithium-Ion Battery Performance, Ying Liu, Alessandro Palmieri, Junkai He, Yongtao Meng, Nicole Beauregard, Steven L. Suib, William E. Mustain May 2016

Highly Conductive In-Sno2/Rgo Nano-Heterostructures With Improved Lithium-Ion Battery Performance, Ying Liu, Alessandro Palmieri, Junkai He, Yongtao Meng, Nicole Beauregard, Steven L. Suib, William E. Mustain

Faculty Publications

The increasing demand of emerging technologies for high energy density electrochemical storage has led many researchers to look for alternative anode materials to graphite. The most promising conversion and alloying materials do not yet possess acceptable cycle life or rate capability. In this work, we use tin oxide, SnO2, as a representative anode material to explore the influence of graphene incorporation and In-doping to increase the electronic conductivity and concomitantly improve capacity retention and cycle life. It was found that the incorporation of In into SnO2 reduces the charge transfer resistance during cycling, prolonging life. It is also hypothesized that …

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Ubisol-Q10 Prevents Glutamate-Induced Cell Death By Blocking Mitochondrial Fragmentation And Permeability Transition Pore Opening, Santosh Kumari, Suresh L. Mehta, Gaolin Z. Milledge, Xinyu Huang, P Andy Li Apr 2016

Ubisol-Q10 Prevents Glutamate-Induced Cell Death By Blocking Mitochondrial Fragmentation And Permeability Transition Pore Opening, Santosh Kumari, Suresh L. Mehta, Gaolin Z. Milledge, Xinyu Huang, P Andy Li

Faculty Publications

Mitochondrial dysfunction and oxidative stress are the major events that lead to the formation of mitochondrial permeability transition pore (mPTP) during glutamate-induced cytotoxicity and cell death. Coenzyme Q10 (CoQ10) has widely been used for the treatment of mitochondrial disorders and neurodegenerative diseases. Comparing to traditional lipid-soluble CoQ10, water soluble CoQ10 (Ubisol-Q10) has high intracellular and intra-mitochondrial distribution. The aims of the present study are to determine the neuroprotective effects of Ubisol-Q10 on glutamate-induced cell death and to explore its functional mechanisms. HT22 neuronal cells were exposed to glutamate. Cell viability was measured and mitochondrial fragmentation was assessed by mitochondrial imaging. …

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Ray-Based Statistical Propagation Modeling For Indoor Corridor Scenarios At 15 Ghz, Qi Wang, Bo Ai, David W. Matolak, Ruisi He, Xin Zhou Mar 2016

Ray-Based Statistical Propagation Modeling For Indoor Corridor Scenarios At 15 Ghz, Qi Wang, Bo Ai, David W. Matolak, Ruisi He, Xin Zhou

Faculty Publications

According to the demands for fifth-generation (5G) communication systems, high frequency bands (above 6 GHz) need to be adopted to provide additional spectrum. This paper investigates the characteristics of indoor corridor channels at 15 GHz. Channel measurements with a vector network analyzer in two corridors were conducted. Based on a ray-optical approach, a deterministic channel model covering both antenna and propagation characteristic is presented. The channel model is evaluated by comparing simulated results of received power and root mean square delay spread with the corresponding measurements. By removing the impact of directional antennas from the transmitter and receiver, a path …

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