Thermodynamics Commons^™

Prediction Of Vapor/Liquid Equilibrium Behavior From Quantum Mechanical Data, Marshall J. Gnap

Williams Honors College, Honors Research Projects

MOSCED (Modified Separation of Cohesive Energy Density) is a particularly attractive model for activity coefficients because it offers intuitive insights into how to tune solvent-solute interactions to achieve optimized formulations. Unfortunately, only 133 compounds have been characterized with the MOSCED method. Furthermore, there is no convenient method for extending MOSCED predictions to new compounds. The hypothesis of the present research is that the surface charge density of a molecule, once normalized over the molecule surface area, provided graphically by a σ-profile from density functional theory (DFT) computations, can be used to estimate the parameters used in the MOSCED model. DFT …

Characterization Of Iron Phthalocyanine As The Cathode Active Material For Lithium-Ion Batteries, Sarwan S. Sandhu, Joseph P. Fellner

Chemical and Materials Engineering Faculty Publications

The developed thermodynamic functions for the determination of Gibbs free energy, enthalpy, and entropy of formation of solid lithium-iron phthalocyanine (LixFePc) from solid lithium and iron phthalocyanine as a function of x, defined as g-moles of the intercalated lithium per g-mole of iron phthalocyanine, at a fixed set of temperature and pressure conditions are presented. In addition, a proposed expression for the evaluation of lithium diffusion coefficient in solid iron phthalocyanine as a function of both x and temperature, and the experimental results from the ongoing research/development work on the lithium/iron phthalocyanine cells are included.

Thermodynamic Analysis Of Phenylpropanoid Pathway In Arabidopsis Thanliana, Patrick J. Ioerger, Rohit Jaini, John A. Morgan

The Summer Undergraduate Research Fellowship (SURF) Symposium

Biofuels represent a renewable alternative to traditional fossil fuels. As dependence on fossil fuels rise so does the importance of improving the production of alternative fuels. Lignin poses one obstacle in the development of such alternative fuels. Its presence strengthens cell walls and hinders degradation of polysaccharides into monosaccharides, increasing cost and time while decreasing efficiency of the process. Lignin is composed of three monolignols, each of which is produced through the Phenylpropanoid pathway; a series of chemical reactions. This work aims to determine which reactions in the pathway are least thermodynamically favorable and thus most limiting. From metabolic mapping …

Economic And Sustainability Aspects Of Chemical Process Industries By Thermodynamics Analysis, Mahdi H. Alhajji

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

Economics and sustainability improvements of some chemical processes are assessed after the retrofits suggested by thermodynamic analysis and energy analyzer. The main objective is to explore the scope of reducing the energy consumption and CO₂ emissions for a more sustainable operation in chemical process industries. Thermodynamic analysis is carried out by applying the thermal analysis capability of ‘Column Targeting Tool’ to address the ‘energy intensity,’ and/or the ‘Energy Analyzer’ to design and improve the performance of the heat exchanger network system for process heat integration. CTT is based on the ‘Practical Near-Minimum Thermodynamic Condition’ representing a close to practical …

Comparison Of Low-Temperature Co-Fired Ceramic And Direct Bonded Copper For Single Ended Primary Inductance Topology, Kristopher Cody Johnson

Electrical Engineering Undergraduate Honors Theses

This work examines the thermal dissipation characteristics of Low-Temperature Co-fired Ceramic (LTCC) and Direct Bonded Copper (DBC) with the implementation of a Single Ended Primary Inductance Converter (SEPIC) topology. The advantages and disadvantages of the two substrates will be explored in addition to a description of the design and control of the SEPIC. It will be shown that the DBC implementation is superior with regards to thermal dissipation, but that LTCC has advantages in high- density packaging, RF applications, and embedded components. These substrates and converters provide many advantages in industrial applications that include automotive and grid level implementations. Additional …

Characterization Of Nano-Porous Si-Cu Composites To Enhance Lubricant Retention Impacting The Tribological Properties Of Sliding Surfaces, Julius Sheldon Morehead

Graduate Theses and Dissertations

As the expectations for modern machinery's tribological and thermal performances continue to rise, the retention of lubricant on the contact surfaces of their sliding components becomes an increasingly important issue. Friction and wear cause heat-related failures which lead to catastrophic damage to machinery. Evaporation of a lubricant's volatile constituents as well as lubricant migration leads not only to a reduction in lubricant quantity but also in its quality, thus facilitating component failures. In order to enhance component reliability, the surface should incorporate features that actively retain lubricants. The unique properties of nano-porous topographies such as their high surface area-to-volume ratio …

Thermal Invisibility Based On Scattering Cancellation And Mantle Cloaking, M Farhat, P.-Y. Chen, H Bagci, C. Amra, S Guenneau, A Alù

Electrical and Computer Engineering Faculty Research Publications

We theoretically and numerically analyze thermal invisibility based on the concept of scattering cancellation and mantle cloaking. We show that a small object can be made completely invisible to heat diffusion waves, by tailoring the heat conductivity of the spherical shell enclosing the object. This means that the thermal scattering from the object is suppressed, and the heat flow outside the object and the cloak made of these spherical shells behaves as if the object is not present. Thermal invisibility may open new vistas in hiding hot spots in infrared thermography, military furtivity, and electronics heating reduction.

Accidental Poison: Analysis Of 1,4-Butanediol In A Popular Children's Arts And Crafts Toy, Christopher R. Dockery, John H. Shugart, Jonathan D. Parker, William J. Lawson

Faculty Articles

A popular children's arts and crafts toy made international headlines when it was discovered that 1,4-butanediol had been substituted into some of its formulations. The chemical 1,4-butanediol rapidly converts to the date-rape drug g-hydroxybutyric acid (GHB) upon ingestion and resulted in the accidental poisoning of some children. In this experiment, students extract 1,4-butanediol from commercially available toy beads (or prepared simulations) using their knowledge of pharmaceutical chemistry, solubility, etc. Using case studies available in the literature, students develop a quantitative analysis experiment for 1,4-butanediol extracted from the toy beads and, through approximation, relate the extractable amount of 1,4-butanediol to dose-response …

Sustainability And Economic Analysis Of Propylene Carbonate And Polypropylene Carbonate Production Processes Using Co2 And Propylene Oxide, Yaşar Demirel

Yaşar Demirel Publications

Currently, the industrially important polycarbonates are synthesized from bisphenol A and diphenyl carbonate, which are highly toxic and hence other feasible alternatives are preferable. Following the considerable advances on the catalyst for the synthesis of carbonates from CO₂ and propylene oxide (PO), industrial scale processes for the productions of propylene carbonate (PC) and polypropylene carbonate (PPC) have been designed and simulated with sustainability and economic analyses. The CO₂ is supplied by a nearby bioethanol plant, while the PO from a petrochemical process. The first part of the study is for the production of 200 million lb/year cyclic PC …

Modeling Of Spallation Phenomenon In An Arc-Jet Environment, Raghava Sai Chaitanya Davuluri

Theses and Dissertations--Mechanical and Aerospace Engineering

Space vehicles, while entering the planetary atmosphere, experience high loads of heat. Ablative materials are commonly used for a thermal protection system, which undergo mass removal mechanisms to counter the heat rates. Spallation is one of the ablative processes, which is characterized by the ejection of solid particles from the material into the flow. Numerical codes that are used in designing the heat shields ignore this phenomenon. Hence, to evaluate the effectiveness of spallation phenomenon, a numerical model is developed to compute the dynamics and chemistry of the particles. The code is one-way coupled to a CFD code that models …

Energy Intensity And Environmental Impact Metrics Of The Back-End Separation Of Ethylene Plant By Thermodynamic Analysis, Mahdi H. Alhajji, Yaşar Demirel

Department of Chemical and Biomolecular Engineering: Faculty Publications

This study presents metrics of energy intensity and environmental impact of the back-end separation of ethylene plant consisting three interacting distillation columns by thermodynamic analysis. The objective is to explore the scope of reducing the energy for utilities and CO₂ emissions. Thermodynamic analysis is carried out using the column targeting tool (CTT) to address the sustainability metrics of ‘Energy Intensity.’ CTT is based on the ‘Practical Near-Minimum Thermodynamic Condition’ representing a close to practical reversible column operation. Environmental impact metrics are estimated from the carbon tracking options. The carbon tracking are estimated by the CO₂ emission data source …

Technoeconomics And Sustainability Of Renewable Methanol And Ammonia Productions Using Wind Power-Based Hydrogen, Michael J. Matzen, Mahdi H. Alhajji, Yaşar Demirel

Yaşar Demirel Publications

This study analyzes and compares the economics and sustainability aspects of two hydrogenation processes for producing renewable methanol and ammonia by using wind-power based electrolytic hydrogen. Carbon dioxide from an ethanol plant is used for producing methanol, while the nitrogen is supplied by an Air Separation Unit (ASU) for producing ammonia. The capacities are 99.96 mt/day methanol and 1202.55 mt/day anhydrous ammonia. The methanol plant requires 138.37 mt CO₂/day and 19.08 mt H₂/day. The ammonia is synthesized by using 217.72 mt H₂/day and 1009.15 mt N₂/day. The production costs and the carbon …

Evaporation-Induced Formation Of Well-Ordered Surface Patterns On Polymer Films, Wei Sun

Theses and Dissertations--Chemical and Materials Engineering

Various techniques of fabricating surface patterns of small scales have been widely studied due to the potential applications of surface patterns in a variety of areas. It is a challenge to fabricate well-ordered surface area efficiently and economically. Evaporation-induced surface patterning is a promising approach to fabricate well-ordered surface patterns over a large area at low cost. In this study, the evaporation-induced surface patterns with controllable geometrical characteristics have been constructed. The dewetting kinetics on deformable substrate is also investigated.

Using simple templates to control the geometry and the evaporation behavior of a droplet of volatile solvent, various gradient surface …

Measurements And Modeling Of Hydrocarbon Mixture Fluid Properties Under Extreme Temperature And Pressure Conditions, Babatunde A. Bamgbade

Theses and Dissertations

Knowledge of thermodynamic fluid properties, such as density and phase behavior, is important for the design, operation, and safety of several processes including drilling, extraction, transportation, and separation that are required in the petroleum. The knowledge is even more critical at extreme temperature and pressure conditions as the search for more crude oil reserves lead to harsher conditions. Currently, there is dearth of experimental data at these conditions and as such, the predictive capability of the existing modeling tools are unproven. The objective of this research is to develop a fundamental understanding of the impact of molecular architecture on fluid …

Process Simulation Of Biomass Gasification Integrated With A Solid Oxide Fuel Cell Stack, Wayne Doherty, Anthony Reynolds, David Kennedy

Articles

Biomass gasification-solid oxide fuel cell (BG-SOFC) combined heat and power (CHP) systems are of major interest in the context of climate change mitigation, energy security and increasing energy efficiency. Aspen Plus is employed to simulate various BG-SOFC CHP systems. The aim of the research work is to investigate the technical feasibility of these systems and to study the influence of important operating parameters and examine integration options. Systems based on dual fluidised bed steam gasification and tubular SOFC technologies are modelled. The cathode recycle and electric heater integration options are not attractive in comparison to the base case anode recycle …

Growth And Properties Of Carbon Microcoils And Nanocoils, Muneaki Hikita, Robyn Bradford, Khalid Lafdi

Chemical and Materials Engineering Faculty Publications

Various types of coiled carbon filaments have been synthesized using chemical vapor deposition and other methods. These carbon filaments exhibit unique electrical and mechanical properties due to their versatile shapes and structures. To form coiled shapes, different types of catalyst compositions and reactive gases have been explored. Generally, coiled carbon filaments are classified by coil diameter and shape (e.g., microcoil and nanocoil). In this review, coiled carbon filaments are classified into three growth mechanism categories:

(1) bidirectional double helical growth;

(2) bidirectional twisted growth; and

(3) tip single helical or twisted growth.

Next, their synthesis methods and hypothetical growth mechanisms …

Slow Release Of Ions From Internalized Silver Nanoparticles Modifies The Epidermal Growth Factor Signaling Response, Kristen K. Comfort, Elizabeth I. Maurer, Saber M. Hussain

Chemical and Materials Engineering Faculty Publications

Due to their distinctive physiochemical properties, including a robust antibacterial activity and plasmonic capability, hundreds of consumer and medical products contain colloidal silver nanoparticles (AgNPs). However, even at sub-toxic dosages, AgNPs are able to disrupt cell functionality, through a yet unknown mechanism. Moreover, internalized AgNPs have the potential to prolong this disruption, even after the removal of excess particles. In the present study, we evaluated the impact, mechanism of action, and continual effects of 50 nm AgNP exposure on epidermal growth factor (EGF) signal transduction within a human keratinocyte (HaCaT) cell line. After AgNP expose, EGF signaling was initially obstructed …

Balloon Diameter Measurement And Altitude Determination Through Gas And Thermal Properties, Geoff Suiter

Von Braun Symposium Student Posters

No abstract provided.

Does A Plastron Improve Heat Transfer?, Madani A. Khan, Jeffrey Alston, Andrew Guenthner

STAR Program Research Presentations

Superamphiphobic surfaces strongly repel both water and oils. In this work, aluminum coupons are processed by sanding with various grit of sand paper to impart microscale roughness. Subsequent submersion of the aluminum substrate in boiling water grows nanoscale grass-like structures. The oxide layer of Al is slightly soluble in water. During a fast diffusion/equilibrium, Al₂O₃ nanograss grows on the surface. A low energy coating is then deposited on the surface. The micro and nanoscale features create re-entrant structures that trap air enabling contact liquid to be in a Cassie-Baxter state. Superamphiphobicity of the samples were confirmed by …

A Soft Condensed Matter Approach Towards Mathematical Modelling Of Mass Transport And Swelling In Food Grains, Michael Chapwanya, N. Misra

Articles

Soft condensed matter (SCM) physics has recently gained importance for a large class of engineering materials. The treatment of food materials from a soft matter perspective, however, is only at the surface and is gaining importance for understanding the complex phenomena and structure of foods. In this work, we present a theoretical treatment of navy beans from a SCM perspective to describe the hydration kinetics. We solve the transport equations within a porous matrix and employ the Flory–Huggin’s equation for polymer–solvent mixture to balance the osmotic pressure. The swelling of the legume seed is modelled as a moving boundary with …