Thermodynamics Commons^™

Note: A Simple Thermal Gradient Annealing Unit For The Treatment Of Thin Films, C. J. Metting, Johnathan K. Bunn, Ellen A. Underwood, Yihao Zhu, G. Koley, T. Crawford, Jason R. Hattrick-Simpers

Faculty Publications

A gradient annealing cell has been developed for the high-throughput study of thermalannealing effects on thin-film libraries in different environments. The inexpensive gradientannealing unit permits temperature gradients as large as 28 °C/mm and can accommodate samples ranging in length from 13 mm to 51 mm. The system was validated by investigating the effects of annealing temperature on the crystallinity, resistivity, and transparency of tin-doped indium oxide deposited on a glass substrate by magnetron sputtering. The unit developed in this work will permit the rapid optimization of materials properties such as crystallinity, homogeneity, and conductivity across a variety of applications.

Tannic Acid Coated Gold Nanorods Demonstrate A Distinctive Form Of Endosomal Uptake And Unique Distribution Within Cells, Emily A. Untener, Kristen K. Comfort, Elizabeth I. Maurer, Christin M. Grabinski, Donald A. Comfort, Saber M. Hussain

Chemical and Materials Engineering Faculty Publications

One of the primary challenges associated with nanoparticle-dependent biological applications is that endosomal entrapment in a physiological environment severely limits the desired targeting and functionality of the nanoconstructs. This study sought to overcome that challenge through a systematic approach of gold nanorod (GNR) functionalization: evaluating the influence of both aspect ratio and surface chemistry on targeted cellular internalization rates and preservation of particle integrity. Owing to their unique spectral properties and enhanced surface area, GNRs possess great potential for the advancement of nanobased delivery and imaging applications. However, their ability for efficient intracellular delivery while maintaining their specific physiochemical parameters …

Chme 223: Chemical Engineering Thermodynamics I—A Peer Review Of Teaching Project Benchmark Portfolio, Hossein Noureddini

UNL Faculty Course Portfolios

This portfolio was intended to provide a broad overview of the course. Initially, when I decided to write this portfolio my intention was for it to help me in the student's outcome assessment of teaching for the course and in a broader scope, for my department's effort in establishing a systematic student outcome assessment process. However, as I became more familiar with the program I realized other aspects of the course could also benefit from this portfolio. My goal for this portfolio is to be broad with emphasis on course objectives, delivery methods and their assessment. I like for this …

Optimization Of Biodiesel Production Plants, Nghi T. Nguyen

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

A conventional biodiesel plant utilizing two distillation columns to purify unreacted reactants and products is considered in this study. Thermodynamic analyses are used to assess the performance of the existing distillation columns, and reduce the costs of operation by appropriate retrofits in a biodiesel production plant. After the retrofits, the overall exergy loss for the two columns has decreased from 2430.87 kW to 1674.12 kW.

A reactive distillation is developed for esterification of lauric acid with methanol using equilibrium and nonequilibrium models. Equilibrium modeling dominated during last few decades due to their straightforward mathematical modeling. In reality, separation depends on …

Plasmonic Pervaporation Via Gold Nanoparticle-Functionalized Nanocomposite Membranes, Aaron Russell

Graduate Theses and Dissertations

Butanol derived from biological feedstocks has significant potential as a liquid fuel source, but the separation methods used in its production can be prohibitively expensive and are therefore currently the subject of extensive research. Pervaporation is a promising membrane process that is effective in butanol separations, but involves a large energy demand. This study examines the possibility of increasing flux and energy efficiency in pervaporation via plasmonic heating of gold nanoparticle-functionalized, polymer nanocomposite membranes (AuNCMs) in lieu of conventional feed heating. An economic analysis demonstrated that plasmonic pervaporation could achieve significant reductions in energy usage and utility cost in butanol …

Order-Disorder Transition Of Aragonite Nanoparticles In Nacre, Zaiwang Huang, Xiaodong Li

Faculty Publications

Understanding nacre’s bottom-up biomineralization mechanism, particularly, how individual aragonite platelets are formed, has long remained elusive due to its crystallographic peculiarity and structural complexity. Here we report that crystallographic order-disorder transition can be triggered within individual aragonite platelets in pristine nacre by means of heat treatment and/or inelastic deformation, offering a unique opportunity to discriminate mysterious aragonite nanoparticles in transmission electron microscopy. Our findings unambiguously uncover why aragonite nanoparticles in pristine nacre have long been inaccessible under TEM observation, which is attributed to the monocrystal-polycrystal duality of the aragonite platelet. The underlying physical mechanism for why an individual aragonite platelet …

Carbon Nanotubes Grown On Glass Fiber As A Strain Sensor For Real Time Structural Health Monitoring, Matthew Boehle, Qiong Jiang, Lingchuan Li, Alexandre Lagounov, Khalid Lafdi

Chemical and Materials Engineering Faculty Publications

In order to more effectively monitor the health of composite structures, a fuzzy fiber sensor has been developed. The fuzzy fiber is a bundle of glass fibers with carbon nanotubes or nanofibers (CNTs or CNFs) grown on the surface. The nanotube coating makes the fiber bundle conductive while the small conductive path increases sensitivity. The fuzzy fiber sensor can replace conventional metal foil strain gauges in composite applications. The electrical response of the sensor is monitored in real time to measure strain, vibration, cracking and delamination. Continuous monitoring provides instant notification of any problems. Implementation of this sensor network in …

Heat Transfer Enhancement In A Straight Channel Via A Rotationally Oscillating Adiabatic Cylinder, Ali Beskok, Mehrdad Raisee, Bayram Celik, Bedri Yagiz, Mohsen Cheraghi

Mechanical & Aerospace Engineering Faculty Publications

Heat convection from the uniformly heated walls of a straight channel in presence of a rotationally oscillating cylinder (ROC) is simulated at Re = 100. Heat transfer enhancement due to vortex shedding from the ROC is investigated. Systematic studies are performed to explore the rotation angle and frequency influences on heat transfer by varying the latter in range of the lock-in regime and the former from 0 to 2 π/3. All simulation results are based on the numerical solutions of two-dimensional, unsteady, incompressible Navier-Stokes and energy equations using an h/p type finite element algorithm. Considering time periodicity of the resulting …

Analysis Of Biomass/Coal Co-Gasification For Integrated Gasification Combined Cycle (Igcc) Systems With Carbon Capture, Henry A. Long Iii

LSU New Orleans Theses and Dissertations

In recent years, Integrated Gasification Combined Cycle Technology (IGCC) has become more common in clean coal power operations with carbon capture and sequestration (CCS). Great efforts have been spent on investigating ways to improve the efficiency, reduce costs, and further reduce greenhouse gas emissions. This study focuses on investigating two approaches to achieve these goals. First, replace the subcritical Rankine steam cycle with a supercritical steam cycle. Second, add different amounts of biomass as feedstock to reduce emissions. Finally, implement several types of CCS, including sweet- and sour-shift pre-combustion and post-combustion.

Using the software, Thermoflow®, this study shows that utilizing …

The Occurrence Of False Positive Tests For Gunshot Residue Based On Simulations Of The Suspect's Occupation, Christopher R. Dockery, Matthew B. Rosenberg, Kimberly Kammerdiener, Lauren E. Mcadams

Faculty Articles

Samples collected from high-risk occupations, or simulations thereof, are analyzed for elemental composition using laser-induced breakdown spectroscopy (LlBS) to determine the occurrence of false positive gunshot residue results generated in the work environment. Previous work involving the study of lifetime of detectable amounts of gunshot residue on the hands of a suspect shooter found that gunshot residue exists up to 5.27 days after a firearm discharge. However, certain environmental and/or occupational false positive tests for gunshot residue could result when sampling non-shooters. Samples collected from occupations or simulations thereof include welding, pyrotechnics, key cutting, mechanics, and paper products all of …

Rayleigh Test Apparatus Design Report, Josef Duller, Owen Raybould, James Nicovich

Mechanical Engineering

The Rayleigh Test Apparatus is a device that will be used to test the thermodynamic properties of Nitrous Oxide to assess the feasibility of using this fluid as a coolant for a hybrid rocket aero spike. The aero spike is intended to redirect the propulsion flow as it leaves the engine to create a more efficient flow pattern at low and high altitudes. However, there are issues of overheating which leads to melting of the aero spike. For this reason, the use of nitrous oxide (N2O) as a coolant is being explored. N20 is being considered because it is already …

Optimizing Compressed Air Storage For Energy Efficiency, Brian Abels, J. Kelly Kissock

Mechanical and Aerospace Engineering Faculty Publications

Compressed air storage is an important, but often misunderstood, component of compressed air systems. This paper discusses methods to properly size compressed air storage in load-unload systems to avoid short cycling and reduce system energy use. First, key equations relating storage, pressure, and compressed air flow are derived using fundamental thermodynamic relations. Next, these relations are used to calculate the relation between volume of storage and cycle time in load-unload compressors. It is shown that cycle time is minimized when compressed air demand is 50% of compressor capacity. The effect of pressure drop between compressor system and storage on cycle …

Using Thermally Coupled Reactive Distillation Columns In Biodiesel Production, Nghi Nguyen, Yaşar Demirel

Yaşar Demirel Publications

Production of ethyl dodecanoate (biodiesel) using lauric acid and methanol with a solid acid catalyst of sulfated zirconia is studied by using two distillation sequences. In the first sequence, the methanol recovery column follows the reactive distillation column. In the second sequence, the reactive distillation and methanol recovery columns are thermally coupled. Thermally coupled distillation sequences may consume less energy by allowing interconnecting vapor and liquid streams between the two columns to elminate reboiler or condenser or both. Here we study the thermally coupled side-stripper reactive distillation and eliminate the condenser of the reactive distillation column. Both the sequences are …

Fourier Transform Emission Spectroscopy Of Yh And Yd: Observation Of New A¹Δ And B¹Π Electronic States, R. S. Ram, G. Li, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

The emission spectra of YH and YD molecules have been investigated in the 3600–12 000 cm⁻¹ region using a Fourier transform spectrometer. Molecules were formed in an yttrium hollow cathode lamp operated with a continuous flow of a mixture of Ne and Ar gases, and YH and YD were observed together in the same spectra. A group of bands observed near 1 μm have been identified as 0-0 and 1-1 bands of the A¹Δ-X¹Σ⁺ and B¹Π-X¹Σ⁺ transitions of YH and the 0-0 bands of the same two transitions …

Scaling Properties At Freeze-Out In Relativistic Heavy-Ion Collisions, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, B. D. Anderson, S. Bueltmann, I. Koralt, D. Plyku, Star Collaboration

Physics Faculty Publications

Identified charged pion, kaon, and proton spectra are used to explore the system size dependence of bulk freeze-out properties in Cu+Cu collisions at √sNN=200 and 62.4 GeV. The data are studied with hydrodynamically motivated blast-wave and statistical model frameworks in order to characterize the freeze-out properties of the system. The dependence of freeze-out parameters on beam energy and collision centrality is discussed. Using the existing results from Au + Au and pp collisions, the dependence of freeze-out parameters on the system size is also explored. This multidimensional systematic study furthers our understanding of the QCD phase diagram revealing the importance …

Computer Simulation Of A Biomass Gasification-Solid Oxide Fuel Cell Power System Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy

Articles

The operation and performance of a solid oxide fuel cell (SOFC) stack on biomass syn-gas from a biomass gasification combined heat and power (CHP) plant is investigated. The objective of this work is to develop a model of a biomass-SOFC system capable of predicting performance under diverse operating conditions. The tubular SOFC technology is selected. The SOFC stack model, equilibrium type based on Gibbs free energy minimisation, is developed using Aspen Plus. The model performs heat and mass balances and considers ohmic, activation and concentration losses for the voltage calculation. The model is validated against data available in the literature …

Simulation Of A Tubular Solid Oxide Fuel Cell Stack Operating On Biomass Syngas Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy

Articles

A tubular solid oxide fuel cell (SOFC) stack was modelled and its operation on biomass syn-gas was investigated. The objective of this work was to develop a computer simulation model of a biomass gasification-SOFC (BG-SOFC) system capable of predicting performance under various operating conditions and using diverse fuels. The stack was modelled using Aspen Plus and considers ohmic, activation and concentration losses. It was validated against published data for operation on natural gas. Operating parameters such as fuel and air utilisation factor U_f and U_a, current density j and steam to carbon ratio STCR were varied and …

Nonequilibrium Thermodynamics Modeling Of Coupled Biochemical Cycles In Living Cells, Yaşar Demirel

Yaşar Demirel Publications

Living cells represent open, nonequilibrium, self organizing, and dissipative systems maintained with the continuous supply of outside and inside material, energy, and information flows. The energy in the form of adenosine triphosphate is utilized in biochemical cycles, transport processes, protein synthesis, reproduction, and performing other biological work. The processes in molecular and cellular biological systems are stochastic in nature with varying spatial and time scales, and bounded with conservation laws, kinetic laws, and thermodynamic constraints, which should be taken into account by any approach for modeling biological systems. In component biology, this review focuses on the modeling of enzyme kinetics …