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Articles 1291 - 1320 of 1430

Full-Text Articles in Chemical Engineering

Modelling And Analysis Of The Elution Stage Of "Perfusion Chromatography" Effects Of Intraparticle Convective Velocity And Microsphere Size On System Performance, Y. Xu, Athanasios I. Liapis Feb 1996

Modelling And Analysis Of The Elution Stage Of "Perfusion Chromatography" Effects Of Intraparticle Convective Velocity And Microsphere Size On System Performance, Y. Xu, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

A mathematical model describing the dynamic elution (elution stage) in columns with spherical bidisperse perfusive or spherical bidisperse purely diffusive adsorbent particles is presented and its solution is obtained numerically. The desorption of bovine serum albumin (BSA) from spherical anion-exchange porous particles was studied for different values of the intraparticle Peclet numbers of the adsorbate, (Peintra)a, and eluent, (Peintra)e, and of the microsphere diameter, dm. It was found that as (Peintra)a increases, the asymmetry of the elution peak of the adsorbate (at the exit of the column) decreases, the peak height increases and the time, Te, required for the elution …

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A Robust Path Tracking Algorithm For Homotopy Continuation, S. H. Choi, D. A. Harney, Neil L. Book Jan 1996

A Robust Path Tracking Algorithm For Homotopy Continuation, S. H. Choi, D. A. Harney, Neil L. Book

Chemical and Biochemical Engineering Faculty Research & Creative Works

Conventional path tracking algorithms used in homotopy continuation systems sometimes miss roots owing to jumping from one segment of the homotopy path to another even if there exists homotopy paths to the roots. A robust path tracking algorithm is proposed which loses significant efficiency only on those portions of the path where segment jumping is likely to occur. The method presented here basically performs the predictor-corrector procedure using the Euler predictor and the Newton corrector. Any available algorithm can be used to control the step size. Robustness is achieved by adding the following rule: control the step size so that …

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Modified Contactor For Experimental Studies Of Mass Transfer And Chemical Reaction Across A Liquid-Liquid Interface, Muthanna H. Al-Dahhan, Charles E. Wicks Jan 1996

Modified Contactor For Experimental Studies Of Mass Transfer And Chemical Reaction Across A Liquid-Liquid Interface, Muthanna H. Al-Dahhan, Charles E. Wicks

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Modified Stirred-Cell Type Contactor Has Been Designed and Tested for its Use in Experimental Investigations of Mass Transfer and Chemical Reaction in Liquid-Liquid Systems. its Design overcomes the Shortcomings of Previously Proposed Contactors. It is Easy to Operate and Has the Ability to Investigate the Effect of a Wide Range of Operating Conditions. the Mixing Performance of the Contactor Was Tested using a Dye Injection and a Tracer Technique. Experiments to Evaluate Mass-Transfer Coefficients Across a Liquid-Liquid Interface Have Been Conducted to Determine its Effectiveness. the Results Verified that the Contactor Could Be Successfully Employed as a Useful Experimental …

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Gas Dynamic Unstart In Superdetonative Ram Accelerators, Kaveh Ghorbanian, James D. Sterling Jan 1996

Gas Dynamic Unstart In Superdetonative Ram Accelerators, Kaveh Ghorbanian, James D. Sterling

Business and Information Technology Faculty Research & Creative Works

In this paper we analyze the reflection of non-reacting shock waves as oblique detonation waves. The 2D, steady, inviscid analysis makes use of detonation polar diagrams to identify incident shock angles that lead to reflected detonations, with and without detonation Mach stem formation. The implications of the results for design and operation of superdetonative ram accelerators are explored. The influence of the projectile forebody geometry, the propellant composition, and the takeover velocity is described. We conclude with a discussion of the significance of these parameters on superdetonative ram accelerator unstart phenomena.

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Enhanced Combustion Pulsejet Engines For Mach 0 To 3 Applications, J. Sterling, K. Ghorbanian, T. Sobota Jan 1996

Enhanced Combustion Pulsejet Engines For Mach 0 To 3 Applications, J. Sterling, K. Ghorbanian, T. Sobota

Business and Information Technology Faculty Research & Creative Works

In this paper, we discuss the cyclic operation of an enhanced combustion pulsejet engine (ECPE) applicable in the Mach number range of 0 to 3. The geometry of this engine naturally provides for integration into a new combined cycle engine with ramjets. As in the operation of conventional pulsejets, an ECPE provides engine aspiration, charge compression, combustion and expansion without the use of turbomachinery. The use of modern electronics, fuel injection, and feedback control offers the potential for performance improvements that could make the ECPE a cost-effective competitor for the turbojet engine. This article describes the operating cycle of a …

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A Lattice Boltzmann Subgrid Model For High Reynolds Number Flows, S. Hou, James D. Sterling, S. Chen, G. D. Doolen Jan 1996

A Lattice Boltzmann Subgrid Model For High Reynolds Number Flows, S. Hou, James D. Sterling, S. Chen, G. D. Doolen

Business and Information Technology Faculty Research & Creative Works

A sub grid turbulence model for the lattice Boltzmann method is proposed for high Reynolds number fluid flow applications. The method, based on the standard Smagorinsky sub grid model and a single-time relaxation lattice Boltzmann method, incorporates the advantages of the lattice Boltzmann method for handling arbitrary boundaries and is easily implemented on parallel machines. The method is applied to a two-dimensional driven cavity flow for studying dynamics and the Reynolds number dependence of the flow structures. The substitution of other sub grid models, such as the dynamic sub grid model, in the framework of the LB method is discussed.

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Unsteady Conjugate Mass Transfer Between A Single Droplet And An Ambient Flow With External Chemical Reaction, Leonid S. Kleinman, X. B. Reed Jan 1996

Unsteady Conjugate Mass Transfer Between A Single Droplet And An Ambient Flow With External Chemical Reaction, Leonid S. Kleinman, X. B. Reed

Chemical and Biochemical Engineering Faculty Research & Creative Works

Unsteady conjugate mass transfer between a spherical bubble, droplet, or particle and a surrounding fluid flow with chemical reaction in the continuous phase has been analyzed. An algorithm based on spectral methods has been developed and implemented for the simulation of the interphase mass transfer. The influence of Pe (convection) and Da (rate of external reaction), but in particular of D (diffusivity ratio) and H (distribution coefficient), which characterize the coupling features of the conjugate mass transfer, is studied in a wider range of parameters than earlier investigations. The asymptotic regime of mass transfer is investigated for long times, and …

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Catalyst Bed Dilution For Improving Catalyst Wetting In Laboratory Trickle-Bed Reactors, Muthanna H. Al-Dahhan, Milorad P. Duduković Jan 1996

Catalyst Bed Dilution For Improving Catalyst Wetting In Laboratory Trickle-Bed Reactors, Muthanna H. Al-Dahhan, Milorad P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Catalyst Bed Dilution Technique Has Found Rather Widespread Applications as a Means of Producing Reliable and Reproducible Results for Successful Scale-Up and Scale-Down When Testing Commercially Used Catalyst Particle Sizes and Alternative Feedstocks in Small-Scale Laboratory Trickle-Bed Reactors. in Such Small-Diameter Laboratory Units When the Catalyst Used in Commercial Units is Employed as the Only Packing, Low Liquid Velocities Lead to Incomplete Catalyst Utilization Due to Incomplete External Catalyst Wetting, Liquid Maldistribution, and Wall Effects. Diluting the Bed with Fines is Recommended to Remedy These Shortcomings. the Effect of the Bed Dilution with Fines on Catalyst Wetting Efficiency, Pressure …

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Evaluation Of Trickle Bed Reactor Models For A Liquid Limited Reaction, Yuanxin Wu, Muthanna H. Al-Dahhan, Mohan R. Khadilkar, Milorad P. Dudukovic Jan 1996

Evaluation Of Trickle Bed Reactor Models For A Liquid Limited Reaction, Yuanxin Wu, Muthanna H. Al-Dahhan, Mohan R. Khadilkar, Milorad P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Isothermal Decomposition of Hydrogen Peroxide on a CuCr Catalyst in a Laboratory Scale Trickle Bed Reactor Was Used to Test Model Predictions of the Dependence of Liquid Reactant Conversion on Space Time for Different Operating Conditions. It is Assured that the Decomposition of Hydrogen Peroxide is a First Order Liquid-Limited Reaction. Comparison of Model Predictions and Experimental Data Indicates that Both External Mass Transfer Effects and Incomplete External Catalyst Wetting Need to Be Accounted For. Dudukovic's (1977) Approximate Model for the Catalyst Effectiveness Factor Adequately Simulates Both Effects.

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Comparison Of Trickle-Bed And Upflow Reactor Performance At High Pressure: Model Predictions And Experimental Observations, M. R. Khadilkar, Y. X. Wu, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic, M. Colakyan Jan 1996

Comparison Of Trickle-Bed And Upflow Reactor Performance At High Pressure: Model Predictions And Experimental Observations, M. R. Khadilkar, Y. X. Wu, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic, M. Colakyan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Comparison of Laboratory Trickle-Bed and Up-Flow Reactors over a Range of Operating Conditions, Which Cover Both Gas and Liquid Reactant Limitations, Has Been Investigated using Hydrogenation of Alpha-Methylstyrene to Cumene in a Hexane Solvent over 2.5% Pd on Alumina Extrudate Catalyst as a Test Reaction. the Results Show that When the Reaction is Gas Limited at Low Pressure and High Liquid Feed Concentration, Trickle Bed Reactor Outperforms the Upflow Reactor. at High Pressure and Low Liquid Feed Concentration, the Reaction Becomes Liquid Limited and Upflow Reactor Performs Better. It is Concluded that the Advantage of Upflow or Downflow Depends on …

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Comparison Of Upflow And Downflow Two-Phase Flow Packed-Bed Reactors With And Without Fines: Experimental Observations, Yuanxin Wu, Mohan R. Khadilkar, Muthanna H. Al-Dahhan, Milorad P. Duduković Jan 1996

Comparison Of Upflow And Downflow Two-Phase Flow Packed-Bed Reactors With And Without Fines: Experimental Observations, Yuanxin Wu, Mohan R. Khadilkar, Muthanna H. Al-Dahhan, Milorad P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

This Study Compares the Performance of Laboratory Trickle-Bed and Upflow Reactors over a Range of Operating Conditions, using the Hydrogenation of Α-Methylstyrene to Cumene in Hexane Solvent over 2.5% Pd on Alumina Extrudate Catalyst as a Test Reaction. It is Shown that the Trickle Bed Performs Better Than the Upflow Reactor at Low Pressures When the Reaction is Gas Limited, Due to Ready Access of the Gas to the Incompletely Externally Wetted Catalyst, While the Upflow Reactor Performs Better at High Pressures When the Liquid Reactant Limitation Controls the Rate, Due to the Completely Wetted Catalyst. Comparison of the Two …

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Influence Of Formation Processes On Oblique Detonation Wave Stabilization, K. Ghorbanian, J. D. Sterling Jan 1996

Influence Of Formation Processes On Oblique Detonation Wave Stabilization, K. Ghorbanian, J. D. Sterling

Business and Information Technology Faculty Research & Creative Works

In this article we report steady, two-dimensional, inviscid solutions for the near field and far field of a supersonic reactive flow over a variable-double-ramp geometry. The incident shock wave compresses and heats the reactants that will combust after flowing some induction length. Upon reaction, a detonation wave forms and intersects the leading wave at some distance from the ramp surface. In this article, reaction-polar diagrams are developed, and the detonation branch solutions are used to investigate the wave interaction processes that may lead to a steady three-wave structure. By considering this formation process new oblique detonation wave stabilization criteria based …

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Size-Dependent Adsorption Models In Microporous Materials. 2. Comparison With Experimental Data, Manuela Giustiniani, Massimiliano Giona, Douglas K. Ludlow Nov 1995

Size-Dependent Adsorption Models In Microporous Materials. 2. Comparison With Experimental Data, Manuela Giustiniani, Massimiliano Giona, Douglas K. Ludlow

Chemical and Biochemical Engineering Faculty Research & Creative Works

In This Article, We Complete the Study of Size-Scaling Effects and of the Keller Model, presenting a Detailed Analysis of the Application of This Model to a Broad Range of Experimental Data on Microporous Materials (In Particular, Activated Carbon and Zeolites). Particular Attention is Focused on the Temperature Dependence of the Freundlich Exponents Αi, on the Functional Form of the Adsorption Energies, and on the Application of Keller Adsorption Isotherms in a Predictive Way to Generic Multicomponent Mixtures. © 1995, American Chemical Society. All Rights Reserved.

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Interphase Mass Transfer From Bubbles, Drops, And Solid Spheres: Diffusional Transport Enhanced By External Chemical Reaction, Leonid S. Kleinman, X. B. Reed Oct 1995

Interphase Mass Transfer From Bubbles, Drops, And Solid Spheres: Diffusional Transport Enhanced By External Chemical Reaction, Leonid S. Kleinman, X. B. Reed

Chemical and Biochemical Engineering Faculty Research & Creative Works

Interphase mass transfer has been analyzed for a reactant being transferred from a sphere into a quiescent, infinite continuous phase where it undergoes a chemical reaction. Ranges of the diffusivity ratio D, the distribution coefficient H, and the Damköhler number Da have been delineated, within which the overall resistance to mass transfer may be reasonably ascribed to the sum of the individual resistances in each of the two phases. Outside these parameter ranges, the resistances for two decoupled mass transfer problems may not be added to give the overall resistance to the coupled mass transfer problem. An alternative procedure for …

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Perfusion Chromatography: Performance Of Periodic Countercurrent Column Operation And Its Comparison With Fixed-Bed Operation, G. A. Heeter, Athanasios I. Liapis Sep 1995

Perfusion Chromatography: Performance Of Periodic Countercurrent Column Operation And Its Comparison With Fixed-Bed Operation, G. A. Heeter, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Simulation studies using mathematical models that describe the single-component adsorption of bovine serum albumin into spherical bidisperse perfusive and spherical bidisperse purely diffusive anion-exchange porous adsorbent particles in a single-column fixed-bed system and in a two-column periodic countercurrent system in which the adsorbent is equally distributed over two beds are presented. The total length of the two-column periodic countercurrent system is equal to the length of the single-column fixed-bed system, and studies are performed for different values of the intraparticle Peclet number, Peintra, and of the microsphere diameter, dm. In the single-column fixed-bed system, the percentage utilization of the adsorptive …

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Precision Total Pressure Measurements Of Propyne With Propane, Propene, And Propadiene, Edward A. Kyser, David B. Manley Jul 1995

Precision Total Pressure Measurements Of Propyne With Propane, Propene, And Propadiene, Edward A. Kyser, David B. Manley

Chemical and Biochemical Engineering Faculty Research & Creative Works

Experimental total pressure measurements of propyne mixed with propane, propene, and propadiene are presented for five isotherms from 253 to 353 K. Thermodynamically consistent vapor compositions and saturated phase densities are calculated using a cubic equation of state with three isothermal pure component parameters and two binary mixture parameters. The precision vapor—liquid equilibrium cell and experimental procedure which are particularly useful for measurements involving close boiling light hydrocarbons are described, and the experimental and modeled results are presented. © 1995, American Chemical Society. All rights reserved.

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Reproducible Technique For Packing Laboratory-Scale Trickle-Bed Reactors With A Mixture Of Catalyst And Fines, Muthanna H. Al-Dahhan, Yuanxin Wu, Milorad P. Duduković Feb 1995

Reproducible Technique For Packing Laboratory-Scale Trickle-Bed Reactors With A Mixture Of Catalyst And Fines, Muthanna H. Al-Dahhan, Yuanxin Wu, Milorad P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Reproducible Procedure for Packing Small-Diameter Packed Beds with a Mixture of Fines and Catalyst is Reported. Such Beds Are Essential for Process Catalyst Testing in Trickle-Flow Reactors. Packing Uniformity Along the Bed, Reproducibility of Single-Phase Pressure Drop and Reproducibility of Liquid Holdup and Two-Phase Flow Pressure Drop in Repacked Beds Has Been Demonstrated. © 1995, American Chemical Society. All Rights Reserved.

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Lntracrystalline Diffusion Of Benzene In Silicalite : Effect Of Structural Heterogeneity, Dhananjai B. Shah, Chang-Jie Guo, David T. Hayhurst Jan 1995

Lntracrystalline Diffusion Of Benzene In Silicalite : Effect Of Structural Heterogeneity, Dhananjai B. Shah, Chang-Jie Guo, David T. Hayhurst

Chemical & Biomedical Engineering Faculty Publications

The sorption kinetics of benzene in silicalite have been measured gravimetrically using large silicalite crystals of sizes 350 µm × 105 µm × 105 µm and 270 µm × 70 µm × 70 µm in the temperature range 283–343 K. Experiments were performed under conditions that ensured isothermal operation with intracrystalline diffusion control. An analytical expression for the Darken's correction factor (δ In P/δ In a) was derived based on the Hill–de-Boer equation and was used to determine the variation of corrected diffusivity with concentration. The transport diffusivity varied significantly with the adsorbed-phase concentration but the …

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Catalyst Wetting Efficiency In Trickle-Bed Reactors At High Pressure, Muthanna H. Al-Dahhan, Milorad P. Duduković Jan 1995

Catalyst Wetting Efficiency In Trickle-Bed Reactors At High Pressure, Muthanna H. Al-Dahhan, Milorad P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

Trickle-Bed Reactors Are Widely Used in Industrial High Pressure Operations (Up to 30 MPa). the Knowledge of Catalyst Wetting Efficiency as a Function of Operating Conditions is Needed for Relating Laboratory and Pilot Scale Reactor Data to Large Scale Reactor Operation. the Available Predictions of the Wetting Efficiency Rest on Data Collected at Atmospheric Pressure. in This Study a Phenomenological Analysis Has Been Developed to Relate the Wetting Efficiency with Operating Conditions Such as Reactor Pressure, Gas and Liquid Flow Rate. Experimental Data for the Wetting Efficiency at High Pressure Have Been Obtained Via a Tracer Technique. the Data Support …

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An Efficient Multicomputer Algorithm For The Solution Of Chemical Process Flowsheeting Equations, Fikret Ercal, Neil L. Book, S. Pait, J. J. Fielding Jan 1995

An Efficient Multicomputer Algorithm For The Solution Of Chemical Process Flowsheeting Equations, Fikret Ercal, Neil L. Book, S. Pait, J. J. Fielding

Computer Science Faculty Research & Creative Works

This paper presents a parallel solution method of large sparse systems of linear equations arising in the context of a chemical process flowsheeting application on a message passing multicomputer. To maximize the performance, the algorithm uses a novel matrix decomposition and solution method, called parallel two-phased LU decomposition, which schedules the concurrent tasks in a maximally overlapping manner, and at the same time, tries to minimize the interprocessor data dependencies and obtain optimal load balancing. The forward elimination step is performed concurrently with the parallel two-phased LU decomposition step and backward substitution is parallelized in a piecewise manner. Implementation results …

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Teaching Statistical Experimental Design Using A Laboratory Experiment, Douglas K. Ludlow, Kirk H. Schulz, John Erjavec Jan 1995

Teaching Statistical Experimental Design Using A Laboratory Experiment, Douglas K. Ludlow, Kirk H. Schulz, John Erjavec

Chemical and Biochemical Engineering Faculty Research & Creative Works

An Experimental Project Introduces the Concepts of Statistical Experimental Design to Undergraduates in a Laboratory Setting. a Safe, Inexpensive and Easily Operable Experiment Uses a Gas Chromatograph to Give Quantitative Results and to Allow Students to Concentrate on Applying Statistical Skills Without Being Impeded by Complex Equipment or Experimental Methods. One of the Unique Aspects of the Experiment is a Trade‐off between the Two Most Significant Variables, Forcing Students to Compromise in the Selection of Optimum Conditions. Such Compromises Are Typical in Many Real‐world Industrial Situations. the Experiment Has Been Used for Several Years in the Undergraduate Chemical Engineering Laboratories …

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Expression Of A Functional Human Complement Inhibitor In A Transgenic Pig As A Model For The Prevention Of Xenogeneic Hyperacute Organ Rejection., William L. Fodor, Barry L. Williams, Louis A. Martis, Josaeph A. Madri, Scott A. Rollins, James W. Knight, William H. Velander, Stephen P. Squinto Nov 1994

Expression Of A Functional Human Complement Inhibitor In A Transgenic Pig As A Model For The Prevention Of Xenogeneic Hyperacute Organ Rejection., William L. Fodor, Barry L. Williams, Louis A. Martis, Josaeph A. Madri, Scott A. Rollins, James W. Knight, William H. Velander, Stephen P. Squinto

Papers in Biotechnology

ABSTRACT The serious shortage of human organs available for transplantation has engendered a heightened interest in the use of animal organs (xenografts) for transplantation. However, the major barrier to successful discordant xenogeneic organ transplantation is the phenomenon of hyperacute rejection. Hyperacute rejection results from the deposition of high-titer preformed antibodies that activate serum complement on the luminal surface of the vascular endothelium, leading to vessel occlusion and graft failure within minutes to hours. Although endogenous membrane-associated complement inhibitors normally protect endothelial cells from autologous complement, they are species restricted and thus confer limited resistance to activated xenogeneic complement. To address …

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Orientation Induced Scattering Asymmetry, Jee-Ching Wang, Ronald E. Olson Aug 1994

Orientation Induced Scattering Asymmetry, Jee-Ching Wang, Ronald E. Olson

Chemical and Biochemical Engineering Faculty Research & Creative Works

Projectile angular scattering is investigated following electron capture by protons from circular Rydberg atoms oriented along a quantization axis perpendicular to the incident projectile direction. We find strong left-right scattering asymmetry as a function of the orientation angle at collision speeds comparable to the electron orbital speed. The capture cross section is dramatically enhanced due to velocity matching when the angular momenta of the proton and the electron are aligned. The scattering asymmetry exhibits characteristic impact parameter dependencies suitable for studying three-body dynamics influenced by both long and short range forces of comparable strength. © 1994 IOP Publishing Ltd.

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Effect Of Culture Conditions, Donor Age, And Injection Site On In Vitro Development Of Dna Microinjected Porcine Zygotes, M A. Hajdu, J W. Knight, R S. Cansecot, R L. Krisher, William H. Velander, R E. Pearson, F C. Gwazdauskas May 1994

Effect Of Culture Conditions, Donor Age, And Injection Site On In Vitro Development Of Dna Microinjected Porcine Zygotes, M A. Hajdu, J W. Knight, R S. Cansecot, R L. Krisher, William H. Velander, R E. Pearson, F C. Gwazdauskas

Papers in Biotechnology

A series of experiments evaluated development of porcine zygotes microinjected with DNA in three culture media and two incubation temperatures, from postpubertal and prepubertal donors, and between zygotes injected with DNA into the pronucleus and the cytoplasm. Zygotes recovered from 36 postpubertal gilts in Exp. 1 were injected and cultured in modified NCSU-23, modified NCSU-37, and CZB media at 37°C or 39°C for 7 d. In Exp. 2, zygotes were collected from postpubertal or prepubertal gilts, microinjected with DNA, and cultured in modified NCSU-23. In Exp. 3 superovulated prepubertal gilts had DNA injected into the cytoplasm or pronucleus of zygotes. …

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Effects Of Time Of Deoxyribonucleic Acid Microinjection On Gene Detection And In Vitro Development Of Bovine Embryos, A.E T. Sparks, R S. Canseco, C G. Russell, J L. Johnson, H D. Moll, William H. Velander, Francis C. Gwazdauskas Mar 1994

Effects Of Time Of Deoxyribonucleic Acid Microinjection On Gene Detection And In Vitro Development Of Bovine Embryos, A.E T. Sparks, R S. Canseco, C G. Russell, J L. Johnson, H D. Moll, William H. Velander, Francis C. Gwazdauskas

Papers in Biotechnology

In vivo fertilized embryos were surgically collected from superovulated dairy cows to evaluate microinjection on embryo development and utilized the polymerase chain reaction technique for selection of transgenic embryos. Seventy-two percent of the embryos with visible pronuclei or nuclei were microinjected with DNA, and the remaining 28% served as uninjected controls. All embryos were cocultured with bovine oviductal epithelial cells. Mean final development scores of embryos within the same initial cell stage at collection were unaffected by microinjection. After 144 h of culture, 45% of the microinjected embryos developed to the morula or blastocyst stage. The transgene was detected in …

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Formation Of Plasma Polymer Thin Films Containing Reactive Metal Chelate Sites, J. M. Skelly, Nicholas C. Morosoff, V. T. Stannett, A. L. Crumbliss Feb 1994

Formation Of Plasma Polymer Thin Films Containing Reactive Metal Chelate Sites, J. M. Skelly, Nicholas C. Morosoff, V. T. Stannett, A. L. Crumbliss

Chemical and Biochemical Engineering Faculty Research & Creative Works

We report here the successful incorporation of chemically active Co2+ and Ni2+ centers into plasma polymer thin films. Metal center incorporation was accomplished by simultaneous plasma polymerization of sublimed Co2+ or Ni2+ complexes with gaseous "comonomers" or Ar. The metal complexes include N,N′-bis(salicylidene)-1,2-phenylenediaminecobalt(II) (CoSalophen), N,N′-bis(salicylidene)ethylenediaminecobalt(II) (CoSalen), N,N′-bis(3-fluorosalicylidene)ethylenediaminecobalt(II) (CoFluomine), meso-tetraphenylporphyrinatocobalt(II) (CoTPP), meso-tetraphenylporphine (TPP), and meso-tetraphenylporphyrinatonickel(II) (NiTPP). Modification to the metal complex structure was observed by IR and UV-vis spectroscopies. IR spectra of plasma polymer films containing the Schiff's base complexes, prepared using Ar as a carrier gas, contained a band at 2190 cm−1, which can be attributed to nitrile group formation, …

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Structural Properties Of Mixtures Of Highly Asymmetrical Electrolytes And Uncharged Particles Using The Hypernetted Chain Approximation, Daniel Forciniti, Carol K. Hall Jan 1994

Structural Properties Of Mixtures Of Highly Asymmetrical Electrolytes And Uncharged Particles Using The Hypernetted Chain Approximation, Daniel Forciniti, Carol K. Hall

Chemical and Biochemical Engineering Faculty Research & Creative Works

We have solved the Ornstein-Zernike equation in the hypernetted chain (HNC) approximation for several mixtures of electrolytes and uncharged hard spheres. The mixtures that we studied range from a simple restricted primitive model plus hard spheres of the same size to highly asymmetric electrolytes plus hard spheres of different sizes. We monitored the radial distribution function and thermodynamic properties. We find that the presence of neutral particles changes the nature of the interaction between the charged particles. We also find a strong correlation between nonelectrostatic and electrostatic contributions to the free energy of the mixtures. Potential applications of this approach …

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Dominance Of The Thomas Mechanism For Electron Capture From Orientated Rydberg Atoms, Jee-Ching Wang, Ronald E. Olson Jan 1994

Dominance Of The Thomas Mechanism For Electron Capture From Orientated Rydberg Atoms, Jee-Ching Wang, Ronald E. Olson

Chemical and Biochemical Engineering Faculty Research & Creative Works

We investigate electron capture from initially oriented circular Rydberg atoms by proton impact at collision speeds comparable to the electron orbital speed. The Thomas double scattering mechanism is observed even at these low relative speeds. Furthermore, we find evidence for the dominance of a quasi Thomas capture mechanism in the form of not a single peak, but a double-peaked structure in the differential cross section when the plane of the circular orbit is nearly perpendicular to the incident direction of the projectile. © 1994 The American Physical Society.

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Multiphase Equilibrium Behavior Of The Mixture Carbon Dioxide + Ethane + Methanol, Seung Pyo Hong, Christi L. Patton (Luks), Kraemer D. Luke Jan 1994

Multiphase Equilibrium Behavior Of The Mixture Carbon Dioxide + Ethane + Methanol, Seung Pyo Hong, Christi L. Patton (Luks), Kraemer D. Luke

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Three-Phase Liquid-Liquid-Vapor (Llg) Phase Equilibrium Behavior of the Mixture Carbon Dioxide + Ethane + Methanol Was Experimentally Studied. the Boundaries of the Three-Phase Llg Region in Pressure-Temperature Space Are Delineated. Compositions and Molar Volumes of the Two Liquid Phases and the Vapor Phase Along the 288.15 and 298.15 K Isotherms Are Reported. © 1994, American Chemical Society. All Rights Reserved.

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Writing Across The Chemical Engineering Curriculum At The University Of North Dakota, Douglas K. Ludlow, Kirk H. Schulz Jan 1994

Writing Across The Chemical Engineering Curriculum At The University Of North Dakota, Douglas K. Ludlow, Kirk H. Schulz

Chemical and Biochemical Engineering Faculty Research & Creative Works

In Order to Prepare Engineering Graduates with the Written and Oral Communication Skills Needed in their Professional Careers a Coordinated Writing Across the Curriculum (WAC) Program Has Developed in the Chemical Engineering Department at the University of North Dakota. the Students Practice and Develop their Skills with Writing Assignments in Both Lecture and Laboratory Courses from the First‐year Level through the Fourth‐year Capstone Design Course. the Coordinated Approach, especially in the Four‐semester Laboratory Sequence, Allows the Students to Develop their Skills by Building on Communication Experiences in Previous Courses. the WAC Program at UND Including Writing and Public Speaking Assignments …

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