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Articles 421 - 450 of 914
Full-Text Articles in Chemical Engineering
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
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.
Three-Dimensional Engineered Matrix To Study Cancer Stem Cells And Tumorsphere Formation: Effect Of Matrix Modulus, Xiaoming Yang, Samaneh Kamali Sarvestani, Seyedsina Moeinzadeh, Xuezhong He, Esmaiel Jabbari
Three-Dimensional Engineered Matrix To Study Cancer Stem Cells And Tumorsphere Formation: Effect Of Matrix Modulus, Xiaoming Yang, Samaneh Kamali Sarvestani, Seyedsina Moeinzadeh, Xuezhong He, Esmaiel Jabbari
Faculty Publications
Maintenance of cancer stem cells (CSCs) is regulated by the tumor microenvironment. Synthetic hydrogels provide the flexibility to design three-dimensional (3D) matrices to isolate and study individual factors in the tumor microenvironment. The objective of this work was to investigate the effect of matrix modulus on tumorsphere formation by breast cancer cells and maintenance of CSCs in an inert microenvironment without the interference of other factors. In that regard, 4T1 mouse breast cancer cells were encapsulated in inert polyethylene glycol diacrylate hydrogels and the effect of matrix modulus on tumorsphere formation and expression of CSC markers was investigated. The gel …
Exploring The Mechanisms Of Dna Hybridization On A Surface, Terry J. Schmitt, J Brandon Rogers, Thomas A. Knotts Iv
Exploring The Mechanisms Of Dna Hybridization On A Surface, Terry J. Schmitt, J Brandon Rogers, Thomas A. Knotts Iv
Faculty Publications
DNA microarrays are a potentially disruptive technology in the medical field, but their use in such settings is limited by poor reliability. Microarrays work on the principle of hybridization and can only be as reliable as this process is robust, yet little is known at the molecular level about how the surface affects the hybridization process. This work uses advanced molecular simulation techniques and an experimentally parameterized coarse-grain model to determine the mechanism by which hybridization occurs on surfaces. The results show that hybridization proceeds through a mechanism where the untethered (target) strand often flips orientation. For evenly lengthed strands, …
Prediction Of Sawdust Pyrolysis Yields From A Flat-Flame Burner Using The Cpd Model, Aaron D. Lewis, Thomas H. Fletcher
Prediction Of Sawdust Pyrolysis Yields From A Flat-Flame Burner Using The Cpd Model, Aaron D. Lewis, Thomas H. Fletcher
Faculty Publications
High heating rate pyrolysis experiments were performed on a softwood sawdust in a flat-flame burner reactor at temperatures from 1163 to 1433 K with particle residence times ranging from 23 to 102 ms at atmospheric pressure. Volatile yields of the 45−75 μm sawdust were measured and are believed to be similar to those that would occur in an industrial entrained-flow combustor or gasifier. A refractory tar yield near 1.5 wt % (dry, ash-free) was measured. A high percentage of the fully pyrolyzed sawdust char was spherical, having lost the original sawdust structure. It is suggested that the morphology of sawdust …
Characterization Of Macromolecular Structure Of Pyrolysis Products From A Colorado Green River Oil Shale, James L. Hillier, Thomas H. Fletcher, Mark S. Solum, Ronald J. Pugmire
Characterization Of Macromolecular Structure Of Pyrolysis Products From A Colorado Green River Oil Shale, James L. Hillier, Thomas H. Fletcher, Mark S. Solum, Ronald J. Pugmire
Faculty Publications
Volatile products from an oil shale from the Colorado Green River formation were studied by several methods. The oil shale was demineralized, and the resulting kerogen was also chemically analyzed. Both the oil shale and the demineralized kerogen were pyrolyzed at 10 K/min, and the pyrolysis products (light gas, tar, and char) were analyzed using 13C NMR, XPS, GC/MS, and FTIR. Low temperature ashing was performed in order to compare pyrolysis yields of oil shale and demineralized kerogen on a dry ash-free basis. Volatile yields of approximately 75% were achieved in an oil shale retort and 79% in the kerogen …
Coal Char-Co2 Gasification Measurements And Modeling In A Pressurized Flat-Flame Burner, Randy C. Shurtz, Thomas H. Fletcher
Coal Char-Co2 Gasification Measurements And Modeling In A Pressurized Flat-Flame Burner, Randy C. Shurtz, Thomas H. Fletcher
Faculty Publications
A pressurized flat-flame burner (PFFB) was used to conduct coal gasification studies. The PFFB was designed to provide an environment with laminar, dispersed entrained flow, with particle heating rates of ∼105 K/s, pressures of up to 15 atm, and gas temperatures of up to 2000 K. Residence times were varied from 30 to 700 ms in this study. Char gasification studies by CO2 were conducted on a subbituminous coal and 4 bituminous coals in the PFFB. Pressures of 5, 10, and 15 atm were used with gas compositions of 20, 40, and 90 mol % CO2. Gas conditions with peak …
Applications Of High Throughput (Combinatorial) Methodologies To Electronic, Magnetic, Optical, And Energy-Related Materials, Martin L. Green, Ichiro Takeuchi, Jason R. Hattrick-Simpers
Applications Of High Throughput (Combinatorial) Methodologies To Electronic, Magnetic, Optical, And Energy-Related Materials, Martin L. Green, Ichiro Takeuchi, Jason R. Hattrick-Simpers
Faculty Publications
High throughput (combinatorial) materials science methodology is a relatively new research paradigm that offers the promise of rapid and efficient materials screening, optimization, and discovery. The paradigm started in the pharmaceutical industry but was rapidly adopted to accelerate materials research in a wide variety of areas. High throughput experiments are characterized by synthesis of a “library” sample that contains the materials variation of interest (typically composition), and rapid and localized measurement schemes that result in massive data sets. Because the data are collected at the same time on the same “library” sample, they can be highly uniform with respect to …
Capacity Fade Model For Spinel Limn2O4 Electrode, Yiling Dai, Long Cai, Ralph E. White
Capacity Fade Model For Spinel Limn2O4 Electrode, Yiling Dai, Long Cai, Ralph E. White
Faculty Publications
A mathematical model for the capacity fade of a LiMn2O4 (LMO) electrode is developed in this paper by including the acid attack on the active material and the solid electrolyte interphase (SEI) film formation on the LMO particle surface. The acid generated by the LiPF6 and the solvent decompositions are coupled to the manganese (Mn) dissolution. The decrease of the Li ion diffusion coefficient is involved as another contribution to the capacity fade, which is caused by the passive film formation on the active material surface. The effects of cell practical operation/fabrication conditions and kinetics of …
Time-Dependent Deposition Characteristics Of Fine Coal Fly Ash In A Laboratory Gas Turbine Environment, Robert Laycock, Thomas H. Fletcher
Time-Dependent Deposition Characteristics Of Fine Coal Fly Ash In A Laboratory Gas Turbine Environment, Robert Laycock, Thomas H. Fletcher
Faculty Publications
Time-dependent deposition characteristics of fine coal fly ash were measured in the Turbine Accelerated Deposition Facility (TADF) at Brigham Young University. Two samples of subbituminous coal fly ash, with mass mean diameters of 3 and 13 microns, were entrained in a hot gas flow with a gas temperature of 1288 C and Mach number of 0.25. A nickel-based, superalloy metal coupon approximately 0.3 cm thick was held in a hot particle-laden gas stream to simulate deposition in a gas turbine. Tests were conducted with deposition times of 20, 40, and 60 min. Capture efficiencies and surface roughness characteristics (e.g., Ra) …
Computational Identification Of Adaptive Mutants Using The Vert System, James Winkler, Katy Kao
Computational Identification Of Adaptive Mutants Using The Vert System, James Winkler, Katy Kao
Faculty Publications
BackgroundEvolutionary dynamics of microbial organisms can now be visualized using the Visualizing Evolution in Real Time (VERT) system, in which several isogenic strains expressing different fluorescent proteins compete during adaptive evolution and are tracked using fluorescent cell sorting to construct a population history over time. Mutations conferring enhanced growth rates can be detected by observing changes in the fluorescent population proportions.ResultsUsing data obtained from several VERT experiments, we construct a hidden Markov-derived model to detect these adaptive events in VERT experiments without external intervention beyond initial training. Analysis of annotated data revealed that the model achieves consensus with human annotation …
Reactive Rayleigh–Taylor Turbulent Mixing: A One-Dimensional-Turbulence Study, E.D. Gonzalez-Juez, A.R. Kerstein, D.O. Lignell
Reactive Rayleigh–Taylor Turbulent Mixing: A One-Dimensional-Turbulence Study, E.D. Gonzalez-Juez, A.R. Kerstein, D.O. Lignell
Faculty Publications
We study the problem of reactive Rayleigh–Taylor turbulence in the Boussinesq framework using one-dimensional-turbulence (ODT) simulations. In this problem a reaction zone between overlying heavy/cold reactants and underlying light/hot products moves against gravity. First, we show that ODT results for global quantities in non-reactive Rayleigh–Taylor turbulence are within those from direct numerical simulations (DNS). This comparison give us confidence in using ODT to study unexplored flow regimes in the reactive case. Then, we show how ODT predicts an early stage of reactive Rayleigh–Taylor turbulence that behaves similarly to the non-reactive case, as observed in previous DNS. More importantly, ODT indicates …
Fib/Sem-Based Calculation Of Tortuosity In A Porous Licoo2 Cathode For A Li-Ion Battery, T. Hutzenlaub, A. Asthana, J. Becker, D. R. Wheeler, R. Zengerle, S. Thiele
Fib/Sem-Based Calculation Of Tortuosity In A Porous Licoo2 Cathode For A Li-Ion Battery, T. Hutzenlaub, A. Asthana, J. Becker, D. R. Wheeler, R. Zengerle, S. Thiele
Faculty Publications
We present a new method to quantify tortuosity in the porous, LiCoO2 cathode of a Li-ion battery. The starting point is a previously published 3D reconstruction from FIB/SEM images with three phases, the active material domain, carbon-binder domain and pore space. Based on this geometrical configuration, we compute effective diffusivities, from which we in turn derive tortuosity values for the pore space ranging between 5 and 11.6 for the three spatial directions. In a next step, we compare our approach to an imaging method that employs back-filling material. These methods do not differentiate between the carbon-binder domain and the pore …
Beyond Gel Electrophoresis: Microfluidic Separations, Fluorescence Burst Analysis, And Dna Stretching, Kevin D. Dorfman, Scott B. King, Daniel W. Olson, Joel D. P. Thomas, Douglas R. Tree
Beyond Gel Electrophoresis: Microfluidic Separations, Fluorescence Burst Analysis, And Dna Stretching, Kevin D. Dorfman, Scott B. King, Daniel W. Olson, Joel D. P. Thomas, Douglas R. Tree
Faculty Publications
This review addresses methods for obtaining sequence information directly from unamplified genomic length DNA. Our generic starting point is a large piece of DNA that contains many thousands of base pairs (kilobase pairs, kbp) or even millions of base pairs (megabase pairs, Mbp). We would like to determine the genomic distance between two repeats of a given sequence, indicated by the red dots on the coiled DNA molecule in Figure 1. Let us consider the case where these sequences are restriction sites, which can be selectively cut using proteins known as restriction enzymes. For decades, gel electrophoresis served as the …
Defining The Role Of Ultrasound In Drug Delivery, William G. Pitt
Defining The Role Of Ultrasound In Drug Delivery, William G. Pitt
Faculty Publications
Ultrasound is a very effective modality for drug delivery because energy that is noninvasively transmitted through the skin can be focused on a specific location and employed to release drug at that site. Most of the drug delivery techniques employ one or both of the results of ultrasonic insonation – the generation of thermal energy, called hyperthermia, or the oscillation of gas bubbles, called acoustic cavitation. Cavitation perturbs cell membrane structures via several modes and increases the permeability to drugs or other solutes. Microconvection, caused by stable cavitation, shears cell membranes. The shock waves and fluid jets of inertial cavitation …
Phase Transitions Of Nanoemulsions Using Ultrasound: Experimental Observations, Ram Singh, Ghaleb A. Husseini, William G. Pitt
Phase Transitions Of Nanoemulsions Using Ultrasound: Experimental Observations, Ram Singh, Ghaleb A. Husseini, William G. Pitt
Faculty Publications
The ultrasound-induced transformation of perfluorocarbon liquids to gases is of interest in the area of drug and gene delivery. In this study, three independent parameters (temperature, size, and perfluorocarbon species) were selected to investigate the effects of 476-kHz and 20-kHz ultrasound on nanoemulsion phase transition. Two levels of each factor (low and high) were considered at each frequency. The acoustic intensities at gas bubble formation and at the onset of inertial cavitation were recorded and subsequently correlated with the acoustic parameters. Experimental data showed that low frequencies are more effective in forming and collapsing a bubble. Additionally, as the size …
Solid Oxide Fuel Cells With Both High Voltage And Power Output By Utilizing Beneficial Interfacial Reaction, Chao Su, Zongping Shao, Ye Lin, Yuzhou Wu, Huanting Wang
Solid Oxide Fuel Cells With Both High Voltage And Power Output By Utilizing Beneficial Interfacial Reaction, Chao Su, Zongping Shao, Ye Lin, Yuzhou Wu, Huanting Wang
Faculty Publications
An intriguing cell concept by applying proton-conducting oxide as the ionic conducting phase in the anode and taking advantage of beneficial interfacial reaction between anode and electrolyte is proposed to successfully achieve both high open circuit voltage (OCV) and power output for SOFCs with thin-film samarium doped ceria (SDC) electrolyte at temperatures higher than 600 °C. The fuel cells were fabricated by conventional route without introducing an additional processing step. A very thin and dense interfacial layer (2–3 μm) with compositional gradient was created by in situ reaction between anode and electrolyte although the anode substrate had high surface roughness …
Order-Disorder Transition Of Aragonite Nanoparticles In Nacre, Zaiwang Huang, Xiaodong Li
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 …
Constrained Control And Optimization Of Tubular Solid Oxide Fuel Cells For Extending Cell Lifetime, Ben Spivey, John Hedengren, Thomas F. Edgar
Constrained Control And Optimization Of Tubular Solid Oxide Fuel Cells For Extending Cell Lifetime, Ben Spivey, John Hedengren, Thomas F. Edgar
Faculty Publications
Extending fuel cell lifetime is a necessary objective for reducing fuel cell power generation cost of electricity. Capital costs comprise the most significant fraction of the cost of electricity. Reducing the frequency of fuel cell replacement can be achieved by implementing a control strategy that prevents excursions into operating regions causing failure. In this paper we implement a constrained MIMO model predictive controller (MPC) to avoid the failure modes relevant for a high-temperature tubular solid oxide fuel cell (SOFC) system while performing load-following. The primary causes of failure are catalyst poisoning, fuel or air starvation, carbon deposition, and microcracking. Prior …
Multiple Molecule Effects On The Cooperativity Of Protein Folding Transitions In Simulations, Jacob I. Lewis, Devin J. Moss, Thomas A. Knotts Iv
Multiple Molecule Effects On The Cooperativity Of Protein Folding Transitions In Simulations, Jacob I. Lewis, Devin J. Moss, Thomas A. Knotts Iv
Faculty Publications
Though molecular simulation of proteins has made notable contributions to the study of protein folding and kinetics, disagreement between simulation and experiment still exists. One of the criticisms levied against simulation is its failure to reproduce cooperative protein folding transitions. This weakness has been attributed to many factors such as a lack of polarizability and adequate capturing of solvent effects. This work, however, investigates how increasing the number of proteins simulated simultaneously can affect the cooperativity of folding transitions — a topic that has received little attention previously. Two proteins are studied in this work: phage T4 lysozyme (Protein Data …
Developing And Assessing Leadership In Engineering Students, W. Vincent Wilding, Thomas A. Knotts, William G. Pitt, Morris D. Argyle
Developing And Assessing Leadership In Engineering Students, W. Vincent Wilding, Thomas A. Knotts, William G. Pitt, Morris D. Argyle
Faculty Publications
Developing and Assessing Leadership in Engineering Students W. Vincent Wilding, Thomas A. Knotts IV, William G. Pitt, and Morris D. Argyle Department of Chemical Engineering, Brigham Young University The Ira A. Fulton College of Engineering and Technology at Brigham Young University is focusing on five initiatives: Leadership, Innovation, Global Awareness, Character, Technical Excellence. Efforts in the realm of leadership include freshmen leadership seminars and a required sophomore course entitled Global Leadership in a Technological World. Departments within the college are expected to build on this foundation in the junior and senior years. The Chemical Engineering Department has developed an effective …
A New Assessment Method To Easily Identify Areas Needing Improvement In Course-Level Learning Outcomes, Thomas Knotts, W. Vincent Wilding, William G. Pitt, Morris D. Argyle
A New Assessment Method To Easily Identify Areas Needing Improvement In Course-Level Learning Outcomes, Thomas Knotts, W. Vincent Wilding, William G. Pitt, Morris D. Argyle
Faculty Publications
A New Assessment Method to Easily Identify Areas Needing Improvement Course‐level Learning Outcomes Thomas A. Knotts IV, W. Vincent Wilding, William G. Pitt, and Morris D. Argyle Department of Chemical Engineering, Brigham Young University Assessment of student proficiency in expected outcomes, whether on the course or program level, is an important aspect of curriculum development in engineering programs. The reasons for such assessment range from desires to improve student learning to fulfilling requirements of various accreditation bodies. But regardless of the reasons, the challenge is to develop suitable metrics which can clearly identify areas which need improvement. In order to …
Fiber Optic Monitoring Of Subsea Equipment, David Brower, John Hedengren, Cory Loegering, Alexis Brower, Karl Witherow, Karl Winter
Fiber Optic Monitoring Of Subsea Equipment, David Brower, John Hedengren, Cory Loegering, Alexis Brower, Karl Witherow, Karl Winter
Faculty Publications
Bass Lite deepwater field in the Gulf of Mexico, at water depths of approximately 2,050 m (6,750 feet), commenced operation in February 2008. Natural gas is produced from Bass Lite via a 90-km (56-mile) subsea tieback to the Devils Tower Spar. This project involved several innovations, one of which was the incorporation of a fiber optic sensing system that measures realtime temperature, pressure and strain along the pipeline length. This is a first of its kind innovation that is in actual operation.
Mobility Of A Semiflexible Chain Confined In A Nanochannel, Douglas R. Tree, Yanwei Wang, Kevin D. Dorfman
Mobility Of A Semiflexible Chain Confined In A Nanochannel, Douglas R. Tree, Yanwei Wang, Kevin D. Dorfman
Faculty Publications
The classic results of de Gennes and Odijk describe the mobility of a semiflexible chain confined in a nanochannel only in the limits of very weak and very strong confinement, respectively. Using Monte Carlo sampling of the Kirkwood diffusivity with full hydrodynamic interactions, we show that the mobility of a semiflexible chain exhibits a broad plateau as a function of extension before transitioning to an Odijk regime, and that the width of the plateau depends on the anisotropy of the monomers. For the particular case of DNA in a high ionic strength buffer, which has highly anisotropic monomers, we predict …
Visualizing Evolution In Real-Time Method For Strain Engineering, Luis Reyes, James Winkler, Katy Kao
Visualizing Evolution In Real-Time Method For Strain Engineering, Luis Reyes, James Winkler, Katy Kao
Faculty Publications
The adaptive landscape for an industrially relevant phenotype is determined by the effects of the genetic determinants on the fitness of the microbial system. Identifying the underlying adaptive landscape for a particular phenotype of interest will greatly enhance our abilities to engineer more robust microbial strains. Visualizing evolution in real-time (VERT) is a recently developed method based on in vitro adaptive evolution that facilitates the identification of fitter mutants throughout the course of evolution. Combined with high-throughput genomic tools, VERT can greatly enhance the mapping of adaptive landscapes of industrially relevant phenotypes in microbial systems, thereby expanding our knowledge on …
A Pressure Gauge Based On Gas Density Measurement From Analysis Of The Thermal Noise Of An Atomic Force Microscope Cantilever, Dongjin Seo, Mark R. Paul, Willian A. Ducker
A Pressure Gauge Based On Gas Density Measurement From Analysis Of The Thermal Noise Of An Atomic Force Microscope Cantilever, Dongjin Seo, Mark R. Paul, Willian A. Ducker
Faculty Publications
We describe a gas-density gauge based on the analysis of the thermally-driven fluctuations of an atomic force microscope (AFM) cantilever. The fluctuations are modeled as a ring-down of a simple harmonic oscillator, which allows fitting of the resonance frequency and damping of the cantilever, which in turn yields the gas density. The pressure is obtained from the density using the known equation of state. In the range 10–220 kPa, the pressure readings from the cantilever gauge deviate by an average of only about 5% from pressure readings on a commercial gauge. The theoretical description we use to determine the pressure …
Mesh Adaption For Efficient Multiscale Implementation Of One-Dimensional Turbulence, D. O. Lignell, A. R. Kerstein, G. Sun, E. I. Monson
Mesh Adaption For Efficient Multiscale Implementation Of One-Dimensional Turbulence, D. O. Lignell, A. R. Kerstein, G. Sun, E. I. Monson
Faculty Publications
One-Dimensional Turbulence (ODT) is a stochastic model for turbulent flow simulation. In an atmospheric context, it is analogous to single-column modeling (SCM) in that it lives on a 1D spatial domain, but different in that it time advances individual flow realizations rather than ensemble-averaged quantities. The lack of averaging enables a physically sound multiscale treatment, which is useful for resolving sporadic localized phenomena, as seen in stably stratified regimes, and sharp interfaces, as observed where a convective layer encounters a stable overlying zone. In such flows, the relevant scale range is so large that it is beneficial to enhance model …
One-Dimensional-Turbulence Simulation Of Flame Extinction And Reignition In Planar Ethylene Jet Flames, David O. Lignell, Devin Rappleye
One-Dimensional-Turbulence Simulation Of Flame Extinction And Reignition In Planar Ethylene Jet Flames, David O. Lignell, Devin Rappleye
Faculty Publications
A series of three simulations of temporally evolving, planar, nonpremixed ethylene jet flames are performed using the one-dimensional-turbulence (ODT) model. The simulations are performed at a fixed Reynolds number, but varying Damköhler numbers, under conditions that result in significant flame extinction and reignition. Results are compared to corresponding direct numerical simulations (DNSs), which exhibit 40, 70, and nearly 100% peak flame extinction among the three cases. The planar, temporal configuration is ideal for comparison and validation of the ODT model, and identical thermodynamic, transport, and kinetic models were used. The ODT model captures the jet evolution and heat …
Chemical Potential Perturbation: Extension Of The Method To Lattice Sum Treatment Of Intermolecular Potentials, Stan G. Moore, Dean R. Wheeler
Chemical Potential Perturbation: Extension Of The Method To Lattice Sum Treatment Of Intermolecular Potentials, Stan G. Moore, Dean R. Wheeler
Faculty Publications
The recently developed chemical potential perturbation (CPP) method [S. G. Moore and D. R. Wheeler, J. Chem. Phys. 134, 114514 (2011) https://doi.org/10.1063/1.3561865.] is extended to the lattice (Ewald) sum treatment of intermolecular potentials. The CPP method predicts chemical potentials for a range of composition points using the local (position-dependent) pressure tensor of an inhomogeneous system. When computing the local pressure tensor, one can use the Irving-Kirkwood (IK) or Harasima (H) contours of distributing the pressure. We compare these two contours and show that for a planar interface, the homogeneous pressure and resulting chemical potential can be approximated with …
State Of Charge And Loss Of Active Material Estimation Of A Lithium Ion Cell Under Low Earth Orbit Condition Using Kalman Filtering Approaches, Saeed Khaleghi Rahimian, Sean Rayman, Ralph E. White
State Of Charge And Loss Of Active Material Estimation Of A Lithium Ion Cell Under Low Earth Orbit Condition Using Kalman Filtering Approaches, Saeed Khaleghi Rahimian, Sean Rayman, Ralph E. White
Faculty Publications
The state of charge (SOC) and the loss of active material of the electrodes of a Li ion cell under Low Earth Orbit condition (LEO) have been estimated using Kalman filtering methods, by means of the physics-based single particle (SP) model. Zero mean Gaussian noise was added to the charge-discharge curves obtained by the SP model to generate synthetic data. Afterwards, nonlinear Filtering approaches including Extended Kalman Filtering (EKF) and Unscented Kalman Filtering (UKF) were applied to predict the true SOC and the electrodes’ degradation, by minimizing the measurement residuals between the model prediction and the synthetic data. The results …
Resolution Limit For Dna Barcodes In The Odijk Regime, Yanwei Wang, Wes F. Reinhart, Douglas R. Tree, Kevin D. Dorfman
Resolution Limit For Dna Barcodes In The Odijk Regime, Yanwei Wang, Wes F. Reinhart, Douglas R. Tree, Kevin D. Dorfman
Faculty Publications
We develop an approximation for the probability of optically resolving two fluorescent labels on the backbone of a DNA molecule confined in a nanochannel in the Odijk regime as a function of the fluorescence wavelength, channel size, and the properties of the DNA (persistence length and effective width). The theoretical predictions agree well with equivalent data produced by Monte Carlo simulations of a touching wormlike bead model of DNA in a high ionic strength buffer. Although the theory is only strictly valid in the limit where the effective width of the nanochannel is small compared with the persistence length of …