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Articles 1 - 11 of 11
Full-Text Articles in Engineering
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 …
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 …
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 …
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 …
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 …
Deposition Near Film Cooling Holes On A High Pressure Turbine Vane, Weiguo Ai, Nathan Murray, Thomas H. Fletcher, Spencer Harding, Scott Lewis, Jeffrey P. Bons
Deposition Near Film Cooling Holes On A High Pressure Turbine Vane, Weiguo Ai, Nathan Murray, Thomas H. Fletcher, Spencer Harding, Scott Lewis, Jeffrey P. Bons
Faculty Publications
Deposition on film-cooled turbine components was studied in an accelerated test facility. The accelerated deposition facility seeds a natural-gas burning combustor with finely ground coal ash particulate at 1180 C and 180 m/s (M=0.25). Both cylindrical and shaped holes, with and without thermal barrier coating, were studied over a range of blowing ratios from 0.5 to 4.0. Coolant density ratios were maintained at values from 2.1 to 2.4. Deposition patterns generated with the cylindrical film cooling holes indicated regions of low deposition in the path of the coolant with heightened deposition between film holes. This distinctive pattern was more accentuated …
Prediction Of Tar And Light Gas During Pyrolysis Of Black Liquor And Biomass, Thomas H. Fletcher, Harland R. Pond, Jarom Webster, Judson Wooters, Larry L. Baxter
Prediction Of Tar And Light Gas During Pyrolysis Of Black Liquor And Biomass, Thomas H. Fletcher, Harland R. Pond, Jarom Webster, Judson Wooters, Larry L. Baxter
Faculty Publications
A generalized model for describing the pyrolysis behavior of low-grade fuels is being developed for incorporation into larger combustion simulation models. Light gas and tar yields from black liquor or biomass pyrolysis can be predicted using the chemical percolation devolatilization (CPD) model originally developed for coal. The initial approach is to measure the average chemical structures in a black liquor sample using 13C NMR spectroscopy. These chemical structures are then used in pyrolysis model predictions. With few changes from the coal-derived kinetic parameters, the model describes the organic pyrolysis behavior of black liquor samples obtained in a nitrogen-purged furnace. It …
Computational Analysis Of Conjugate Heat Transfer And Particulate Deposition On A High Pressure Turbine Vane, Weiguo Ai, Thomas H. Fletcher
Computational Analysis Of Conjugate Heat Transfer And Particulate Deposition On A High Pressure Turbine Vane, Weiguo Ai, Thomas H. Fletcher
Faculty Publications
Numerical computations were conducted to simulate flash deposition experiments on gas turbine disk samples with internal impingement and film cooling using a computational fluid dynamics (CFD) code (FLUENT). The standard k-epsilon turbulence model and Reynoldsaveraged Navier–Stokes were employed to compute the flow field and heat transfer. The boundary conditions were specified to be in agreement with the conditions measured in experiments performed in the BYU turbine accelerated deposition facility (TADF). A Lagrangian particle method was utilized to predict the ash particulate deposition. Userdefined subroutines were linked with FLUENT to build the deposition model. The model includes particle sticking/rebounding and particle …
Effect Of Hole Spacing On Deposition Of Fine Coal Flyash Near Film Cooling Holes, Weiguo Ai, Nathan Murray, Thomas H. Fletcher, Spencer Harding, Elizabeth Bonsignore, Jeffrey P. Bons
Effect Of Hole Spacing On Deposition Of Fine Coal Flyash Near Film Cooling Holes, Weiguo Ai, Nathan Murray, Thomas H. Fletcher, Spencer Harding, Elizabeth Bonsignore, Jeffrey P. Bons
Faculty Publications
Particulate deposition experiments were performed in a turbine accelerated deposition facility to examine the nature of flyash deposits near film cooling holes. Deposition on both bare metal and thermal barrier coating (TBC) coupons was studied, with hole spacing (s/d) of 2.25, 3.375, and 4.5. Sub-bituminous coal ash particles (mass mean diameter of 13 microns) were accelerated to a combustor exit flow Mach number of 0.25 and heated to 1183°C before impinging on a target coupon. The particle loading in the 1 h tests was 310 ppmw. Blowing ratios were varied in these experiments from 0 to 4.0 with the density …
Coal Swelling Model For Pressurized High Particle Heating Rate Pyrolysis Applications, Randy C. Shurtz, Joseph W. Hogge, Kade C. Fowers, Gregory S. Sorensen, Thomas H. Fletcher
Coal Swelling Model For Pressurized High Particle Heating Rate Pyrolysis Applications, Randy C. Shurtz, Joseph W. Hogge, Kade C. Fowers, Gregory S. Sorensen, Thomas H. Fletcher
Faculty Publications
A model was previously developed to describe the decrease in swelling during coal pyrolysis at atmospheric pressure when maximum particle heating rates increase from 104 K/s to 105 K/s. That model included effects of coal type using chemical structure properties. This paper presents results of new experiments to study the effects of elevated pressure and high heating rates on coal pyrolysis. A pressurized flat-flame burner (PFFB) was designed and built to conduct these studies. The pyrolysis experiments reported in this paper were conducted at particle heating rates of ∼105 K/s and maximum gas temperatures of 1700 to 1900 …