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Articles 1891 - 1920 of 2019
Full-Text Articles in Chemical Engineering
Electrocatalytic Oxidation Of Formaidehyde And Formic Acid On A Pt/SbAd Electrode, Hong Li, Lincai Jiang, Xiong Jiang
Electrocatalytic Oxidation Of Formaidehyde And Formic Acid On A Pt/SbAd Electrode, Hong Li, Lincai Jiang, Xiong Jiang
Journal of Electrochemistry
The electrocatalytic activity for the oxidation of formaldehyde and formic acid ona Sb-modified platinum (Pt/Sbad) was investigated. Results showed that the Pt/Sbad electrode was electrocatalytically more active than a Pt electrode in the anodic oxidation of formaldehyde and formicacid. In the case of formaldehyde, an oxidation peak appeared at a potential of ca. 0.7V. During the oxidation of formic acid, a 4-fold increase in the 1st peak current was observed. The Sb-modified platinum electrode was found to be most electrocatalytically active at a coverage of 0.75±0.05. The electrocatalytic activity of the Pt/Sbad electrode can be best …
An Efficient Multicomputer Algorithm For The Solution Of Chemical Process Flowsheeting Equations, Fikret Ercal, Neil L. Book, S. Pait, J. J. Fielding
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 …
Orientation Induced Scattering Asymmetry, Jee-Ching Wang, Ronald E. Olson
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.
Sporomorphs And Palynological Interpretations Of Lower Oligocene Strata From The Eastern Gulf Coast, U.S.A., Lisa M. Reeves
Sporomorphs And Palynological Interpretations Of Lower Oligocene Strata From The Eastern Gulf Coast, U.S.A., Lisa M. Reeves
Opportunities for Undergraduate Research Experience Program (OURE)
The Vicksburg Group in the eastern Gulf Coast of the United States belongs to one of the most complete and continuous Paleogene strata in the world. Previous studies in this region have neglected the rich palynomorph assemblages of the Lower Oligocene units of the Vicksburg Group. Four samples from Wayne County Mississippi were analyzed for palynological information on the Vicksburg Group. The initial objective of the study was to understand the principles of palynology and the basis for sporomorph identification. A minimum of 300 specimens were counted per slide to determine the distribution of sporomorphs in the sediments. Two hundred …
Dominance Of The Thomas Mechanism For Electron Capture From Orientated Rydberg Atoms, Jee-Ching Wang, Ronald E. Olson
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.
Final State Distributions For Electron Capture From Orientated Rydberg Atoms, Jee-Ching Wang, Ronald E. Olson
Final State Distributions For Electron Capture From Orientated Rydberg Atoms, Jee-Ching Wang, Ronald E. Olson
Chemical and Biochemical Engineering Faculty Research & Creative Works
Final state nim distributions are studied for electron capture from orientated circular Rydberg atoms. Strong orientation effects are found for all quantum numbers at collision speeds comparable to the electron orbital speed. Predominant population of large m states is observed when the plane of the circular orbit is nearly perpendicular to the incident direction of the projectile. The Ini distributions show structures due to quasi-Thomas scattering even at low relative collision velocities. © 1993 IOP Publishing Ltd.
Ionic Charge Dependence Of The Zero Degree Binary Encounter Peak For Partially Stripped Heavy Ions, W. Wolff, H. E. Wolff, J. L. Shinpaugh, Jee-Ching Wang, Ronald E. Olson, D. Fainstein, S. Lencinas, U. Bechthold, R. Herrmann, H. Schmidt-Bocking
Ionic Charge Dependence Of The Zero Degree Binary Encounter Peak For Partially Stripped Heavy Ions, W. Wolff, H. E. Wolff, J. L. Shinpaugh, Jee-Ching Wang, Ronald E. Olson, D. Fainstein, S. Lencinas, U. Bechthold, R. Herrmann, H. Schmidt-Bocking
Chemical and Biochemical Engineering Faculty Research & Creative Works
We report on the measurements of double differential cross sections, at zero degree, for the production of secondary electrons from the collision of 0, 6 MeV amu-1 Cu5+, I7+, Au11+, U13+, Cu19+, t23+ and Au29+ projectiles with H2 and He. The shapes and positions of the observed binary encounter electron peaks are compared with continuum distorted wave-eikonal initial state (CDW-EIS), impulse approximation and classical trajectory Monte Carlo calculations, as well as with predictions from an adiabatic resonant tunnelling model recently proposed by Fainstein and co-workers. The …
Dependence Of Binary Encounter Electron Production On The Charge State Of The Recoil Ion, Jee-Ching Wang, Ronald E. Olson, H. Wolf, J. Shinpaugh, W. Wolff, H. Schmidt Böcking
Dependence Of Binary Encounter Electron Production On The Charge State Of The Recoil Ion, Jee-Ching Wang, Ronald E. Olson, H. Wolf, J. Shinpaugh, W. Wolff, H. Schmidt Böcking
Chemical and Biochemical Engineering Faculty Research & Creative Works
We study the dependence of the production of binary encounter electrons on the charge state of recoil ions for 2.4 MeV u-l Xe21+ on He and Ar. Doubly differential cross sections of electron emission are calculated with the ncrMC method. We find that the contributions to the binary electron cross section from various recoil ion charge states reach a maximum near Ar5+ for the Ar target. In the case of the He target; double ionization dominates over single ionization for alt ejected electron energies above 100 eV. However, an unexpected local drop of double ionization in the …
Electrostatic Positioning Of Droplets In Turbulent Flows (Lstm 375/Te/93), Nihad E. Daidzic, Adrian Melling
Electrostatic Positioning Of Droplets In Turbulent Flows (Lstm 375/Te/93), Nihad E. Daidzic, Adrian Melling
Aviation Department Publications
Report LSTM 375/TE/93, Lehrstuhl fuer Stroemungsmechanik Universitaet Erlangen-Nuernberg Cauerstr. 4, 8520 Erlangen Germany.
The Effects Of Electron Radiation On The Glass Transition Temperature Of A Polyetherimide, Kristen Tulloch Kern
The Effects Of Electron Radiation On The Glass Transition Temperature Of A Polyetherimide, Kristen Tulloch Kern
Physics Theses & Dissertations
The effects of electron radiation on a polyetherimide (PEI), Ultem*, were investigated. In particular, the changes in the glass transition temperature (Tg) with absorbed radiation dose were studied. The polymer was exposed to mono-energetic beams of 100-keV electrons and 1.0-MeV electrons for doses up to 100 megagray (MGy). Dosimetry for the exposures was based on Monte-Carlo simulations of the transfer of energy from an energetic electron to the polymer and on comparison to Nylon standards. Dynamic mechanical analysis was used to determine the (Tg) for non-exposed PEI and the changes in (Tg) resulting from …
A Computer Simulation Of The Rotary Vacuum Filter Brown Stock Washing System Using Distribution Sampling, Edison G. Yiu
A Computer Simulation Of The Rotary Vacuum Filter Brown Stock Washing System Using Distribution Sampling, Edison G. Yiu
Masters Theses
A probabilistic model was utilized to simulate the brown stock washing system's error due to process variability and measurement noise. Mass balances of the washing system were performed using distribution sampling. This model relies on a nonlinear relationship between displacement and dilution, which permitted the generation of displacement ratio based upon wash liquor ratio. Experimental trials were performed on a pilotscale rotary vacuum single-stage washer. Nonlinear first-order relationship appears to characterize a pilotscale washer adequately. Differences were observed between the means and standard deviations of the measured results compared to the simulation output. Future work is needed to identify the …
Diffraction In The Binary Encounter Electron Peak Observed In Collisions Of 0.6 Mev Amu⁻¹ I7+, I23+ And Au11+ Projectiles With He And Ar, W. Wolff, J. L. Shinpaugh, H. E. Wolff, Ronald E. Olson, Jee-Ching Wang, S. Lencinas, D. Piscevic, R. Herrmann, H. Schmidt-Böcking
Diffraction In The Binary Encounter Electron Peak Observed In Collisions Of 0.6 Mev Amu⁻¹ I7+, I23+ And Au11+ Projectiles With He And Ar, W. Wolff, J. L. Shinpaugh, H. E. Wolff, Ronald E. Olson, Jee-Ching Wang, S. Lencinas, D. Piscevic, R. Herrmann, H. Schmidt-Böcking
Physics Faculty Research & Creative Works
Relative double differential cross sections for electron emission from collisions of 0.6 MeV amu-1I7+and I23+ projectiles with Ar and Au11+projectiles with He were measured for electron energies from 100 eV to 2000 eV and for angles from 0° to 50°. Experimentally observed sudden shifts of the position of the binary encounter peak were interpreted as resulting from quantum interference in the scattering of target electrons from the partially stripped projectile ion. To this end calculations for the elastic scattering of free electrons initially at rest in the laboratory reference frame from the screened …
Prediction Of Paper Color: A Process Simulation Approach, Mayank Chaturvedi
Prediction Of Paper Color: A Process Simulation Approach, Mayank Chaturvedi
Masters Theses
A simulation model was developed for a dye mixing process and for the prediction of the optical properties of the paper. The model was integrated with the MAPPS (Modular Analysis of Pulp and Paper Systems) simulation software package. The model was validated using dyed handsheets made in a laboratory and dyed paper made on a pilot papermachine. Validation comprised of prediction of the optical properties of the handsheets and the machine-made paper which contained various combinations of three non-fluorescent dyes. Sheet reflectances were predicted at 20 nanometer intervals for discrete light wavelength range of 400 to 700 nanometers and verified …
A Mathematical Model And Simulation Of Natural Circulation Loop Thermalhydraulics, Nihad E. Daidzic
A Mathematical Model And Simulation Of Natural Circulation Loop Thermalhydraulics, Nihad E. Daidzic
Aviation Department Publications
In this work, a simple, nonlinear, seventh-order mathematical model with lumped parameter analysis of the thermalhydraulic processes in a natural circulation steam boiler loop is presented. Digital simulation has been performed in order to predict open loop transients in severe accidental situations. Parts of the circulation loop such as the steam drum, downcomer, and riser were modelled separately on the basis of the integral balance equations. The two-phase flow in the steam drum and in the riser was modelled with the aid of a homogeneous-equilibrium, two-phase flow model. Special care was taken to ensure the stability of the numerical scheme, …
Removal Of Mercury From Waste Water: Large-Scale Performance Of An Ion Exchange Process, James A. Ritter, J. P. Bibler
Removal Of Mercury From Waste Water: Large-Scale Performance Of An Ion Exchange Process, James A. Ritter, J. P. Bibler
Faculty Publications
Duolite™ GT-73 ion exchange resin routinely reduces the mercury content of a waste water stream to less than the permitted level of 10 ppb. Effluent concentrations from the ion exchange facility (IEF) are consistently between 1 to 5 ppb, even though the feed contains a varying concentration of mercury (0.2 to 70 ppm). Two operational problems have been encountered at that facility, however. Firstly, the stated capacity of the resin for mercury was not being achieved. The abnormally low capacity was traced to analytical laboratory waste which was intermittently treated by the resin. That waste contained hydrochloric acid, stannous chloride, …
Structural, Depositional, And Diagenetic Controls On Reservoir Development: St. Peter Sandstone, Newaygo County, Michigan, Mark S. Caldwell
Structural, Depositional, And Diagenetic Controls On Reservoir Development: St. Peter Sandstone, Newaygo County, Michigan, Mark S. Caldwell
Masters Theses
Enhanced reservoir quality in the Middle Ordovician St. Peter Sandstone is observed in gas bearing zones in wells located on domal structures. Geometry and degree of this enhanced porosity development is the result of the interplay of structural, depositional, and diagenetic controls. An integrated subsurface study of the Woodville/Goodwell field area was performed in order to document controls on hydrocarbon accumulation.
Recurrent structural growth of domal features throughout the Paleozoic is well documented by isopach mapping. Burial and thermal history studies indicate that hydrocarbons were generated in Ordovician aged source rocks during late Devonian to early Mississippian time, and accumulated …
Thermal Characterization Of Carbon Monoxide Oxidation Catalysts Using Thermogravimetric Analysts And Differential Scanning Calorimetry, Rene A. Bartgis
Thermal Characterization Of Carbon Monoxide Oxidation Catalysts Using Thermogravimetric Analysts And Differential Scanning Calorimetry, Rene A. Bartgis
Chemistry & Biochemistry Theses & Dissertations
Catalysts composed of platinum and/or palladium on tin (IV) oxide supports, with and without silica gel, as well as catalysts composed of gold on manganese oxide, have been developed for the recombination of carbon monoxide and oxygen to form carbon dioxide for use in carbon dioxide lasers. A thermogravimetric method and a differential scanning calorimetric method have been developed for the thermal characterization of these catalysts. The mass loss data and the enthalpy changes determined as the catalysts lost water were then related to existing activity data for these catalysts. No relationship was found between the thermal data and the …
An Experimental Investigation Of The Finite Time Efficiency Of A Peltier Refrigeration Device, Thomas Schneider
An Experimental Investigation Of The Finite Time Efficiency Of A Peltier Refrigeration Device, Thomas Schneider
Dissertations and Theses
Since the need of energy conservation has become more and more urgent in the past decades, there has been an increased interest in the study and development of more efficient energy conversion systems. One of the fields that have arisen from that endeavor is a branch of physics called Finite Time Thermodynamics (FIT). It may be said that FIT was initiated through the famous paper by Curzon and Ahlborn (1975) that established new bounds on the efficiency of a finite time Carnot heat engine. Before, the traditional treatments gave a fundamental upper limit on the efficiency of any heat engine. …
Reactivities Of Some Aromatic Compounds At Supercritical Water Conditions, Chun-Cheng Tsao
Reactivities Of Some Aromatic Compounds At Supercritical Water Conditions, Chun-Cheng Tsao
Masters Theses
The goals of this study are the removal of nitrogen from the extraction products of coal by Supercritical Water and the development of an understanding of the reactions leading to this removal. Six model compounds with structures similar to the intermediates of the coal liquefaction processes were studied. Benzylamine generated toluene through hydrogen abstraction after the C-N bond rupture. To a lesser extent, the oxidation of the benzylic carbon took place leading to benzene formation. Both reaction pathways occurred with equal probability for benzylidenebenzylamine, producing comparable yields of benzene and toluene. Benzaldehyde generated benzene through the oxidation/decarboxylation sequence. Benzyl alcohol …
Removal Of Chlorine From Chlorine-Nitrogen Mixture In A Film Of Liquid Water, Sarwan S. Sandhu
Removal Of Chlorine From Chlorine-Nitrogen Mixture In A Film Of Liquid Water, Sarwan S. Sandhu
Chemical and Materials Engineering Faculty Publications
In industry there are many examples of absorption of a gas with or without chemical reaction in the liquid phase. In physical absorption, a particular gaseous component is removed from a gas mixture due to its larger solubility in the liquid phase solvent. The removal of butane and pentane from a refinery gas mixture by a heavy oil in the liquid phase is an example of physical absorption. In absorption with chemical reaction, the gaseous component to be removed transfers across the gas-liquid interface due to a difference in the bulk chemical potentials or concentrations in the two phases. The …
Model Calculational Approach To The Conformation Of Adsorbed Polypeptide Fragments, Timothy J. Mckeon
Model Calculational Approach To The Conformation Of Adsorbed Polypeptide Fragments, Timothy J. Mckeon
Opportunities for Undergraduate Research Experience Program (OURE)
The focus of the paper is to examine possible conformational changes of peptides when placed in the presence of a poly-synthetic material. A major concern in the pharmaceutical industry is the loss of potency of polypeptide drug products during processing, packaging and storage. An example of this is polymer syringes being used in place of glass ones. The effect is that some protien-derived products experience structural changes due to contact with the polymer. This is otherwise known as surface denaturation. In order to understand the energetics of interfacial polypeptide systems, a calculational approach was used via the program Alchemy. The …
Sedimentology Of The Bedford-Berea Sequence (Early Mississippian), Williams Field, Michigan, David Alan Balthazor
Sedimentology Of The Bedford-Berea Sequence (Early Mississippian), Williams Field, Michigan, David Alan Balthazor
Masters Theses
The Berea Sandstone has produced in excess of 1.6 million barrels of oil in the Williams field since discovery in 1980. Seven lithofacies are identified from conventional core in the Bedford-Berea sequence. These facies are interpreted as deltaic deposits comprising prodelta (Bedford Shale), delta front, destructive marine shale, abandoned distributary channel-fill, interdistributary bay-fill, transgressive marine sandstone, and marine shale (Sunbury Shale) facies. Passive channel-fill facies truncate reservoir sandstone bodies and compartmentalize the field NW-SE across the trend of the northwestplunging anticline.
The two reservoir facies in the Williams field are the delta front and transgressive marine sandstones. The sandstone framework …
Evaluation Of Equilibrium Turbulence For A Hypersonic Boundary Layer At Nonadiabatic Wall Conditions, Cindy W. Albertson
Evaluation Of Equilibrium Turbulence For A Hypersonic Boundary Layer At Nonadiabatic Wall Conditions, Cindy W. Albertson
Mechanical & Aerospace Engineering Theses & Dissertations
This paper presents an experimental study to characterize the compressible turbulent boundary layer produced along a flat plate in the NASA Langley 8-Foot High Temperature Tunnel and determine the test conditions necessary to achieve equilibrium turbulence. In addition, the present study extends the data base for equilibrium compressible turbulent boundary layers over quasi-isothermal walls which are far from the adiabatic wall temperature. The measurements consist of pilot pressure, static pressure, and total temperature distributions in the boundary layer. A flat plate measuring 9.7 feet long and 4.3, feet wide was used for the study to provide a naturally turbulent boundary …
The Effects Of Low Doses (1 To 500 Kilograys) Of 100-Kev Electrons On Four Polymers, Cynthia Anne Bradbury
The Effects Of Low Doses (1 To 500 Kilograys) Of 100-Kev Electrons On Four Polymers, Cynthia Anne Bradbury
Physics Theses & Dissertations
Commercial films of polyetherimide (PEI), polyetheretherimide (PEEI), polyethylene terephthalate (PET), and polycarbonate (PC) were exposed in vacuum to l 00-keV electron radiation to total absorbed doses of l, l 0, l 00, 300, and 500 kilograys. The concentration of radiation-generated radicals, as measured by electron paramagnetic resonance (EPR), increased by over an order of magnitude in all four polymers. Correspondingly, the intensity of the infrared absorption peaks increased uniformly for all doses. Solubility tests resulted in decreased solubility in all polymers. IR, EPR, and solubility suggest dehydrogenation of the aliphatic C-H and phenyl C-H sites. The data indicated that cross …
A Field Perspective On Groundwater Contamination, John A. Cherry
A Field Perspective On Groundwater Contamination, John A. Cherry
Maine Collection
A Field Perspective on Groundwater Contamination
Geological Society of Maine Distinguished Lecturer John Cherry, University of Waterloo, Ontario, sponsored by the Department of Geosciences, University of Southern Maine, 19th May 1988.
Contents: Lecture 1 : Contaminant Migration Processes Illustrated by Field Experiments / Lecture 2 : Behavior of Dense Non-Aqueous Phase Liquids, Illustrated by Lab Experiments and Conceptual Examples / Lecture 3 : Field Case Histories on Groundwater Contamination / Lecture 4 : Hydrogeological Concepts and Criteria for Waste Disposal / Waterloo Center for Groundwater Research Publications List
Statistical Analysis Of A Compound Power-Law Model For Repairable Systems, Max Engelhardt, Lee J. Bain
Statistical Analysis Of A Compound Power-Law Model For Repairable Systems, Max Engelhardt, Lee J. Bain
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Conclusions - A compound (mixed) Poisson distribution is sometimes used as an alternative to the Poisson distribution for count data. Such a compound distribution, which has a negative binomial form, occurs when the population consists of Poisson distributed individuals, but with intensities which have a gamma distribution. A similar situation can occur with a repairable system when failure intensities of each system are different. A more general situation is considered where the system failures are distributed according to nonhomogeneous Poisson processes having Power Law intensity functions with gamma distributed intensity parameter. If the failures of each system in a population …
On The Mean Time Between Failures For Repairable Systems, Max Engelhardt, Lee J. Bain
On The Mean Time Between Failures For Repairable Systems, Max Engelhardt, Lee J. Bain
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Much of the recent work on modeling repairable systems involves Poisson processes with nonconstant intensity functions, viz, nonhomogeneous Poisson processes. Since times between failures are not identically distributed when the process is nonhomogeneous, it is not clear what concept should take the place of the mean time between failures in assessing the reliability of a repairable system. A number of alternate concepts can be found in the literature. We investigate the relationship between two of the most frequently considered alternatives: the reciprocal of the intensity function, and the mean waiting time from t until the next failure. Theorem 1 states …
Approximate Tolerance Limits And Confidence Limits On Reliability For The Gamma Distribution, Lee J. Bain, Max Engelhardt, Wei Kei Shiue
Approximate Tolerance Limits And Confidence Limits On Reliability For The Gamma Distribution, Lee J. Bain, Max Engelhardt, Wei Kei Shiue
Mathematics and Statistics Faculty Research & Creative Works
No abstract provided.
Sequential Probability Ratio Tests For The Shape Parameter Of A Nonhomogeneous Poisson Process, Lee J. Bain, Max Engelhardt
Sequential Probability Ratio Tests For The Shape Parameter Of A Nonhomogeneous Poisson Process, Lee J. Bain, Max Engelhardt
Mathematics and Statistics Faculty Research & Creative Works
Sequential probability ratio tests for the shape parameter of one or more nonhomogeneous Poisson processes, with power intensity functions, are provided. The tests can be performed when the scale parameter is an unknown nuisance parameter; the effective loss of not knowing the scale parameter is one observation per process. The resulting tests can be expressed in terms of the maximum likelihood estimators of the shape parameters for the usual fixed sample procedure. A further advantage of the present approach is that the scale parameters for different processes, in the multiple sample procedures, need not be equal. Approximations for the operating …
The Price Of Oil, R. W. Clack
The Price Of Oil, R. W. Clack
UMR-MEC Conference on Energy / UMR-DNR Conference on Energy
An examination of major forces in the petroleum market with primary emphasis on the decade of the 1970s. The market force (s) responsible for the factor-of-ten increase in the price of crude oil is isolated, if not identified. The market's "message" is set forth for energy policy planners.