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Articles 13441 - 13470 of 14251
Full-Text Articles in Entire DC Network
The Transferability Of Force Constants Among Olefins, John Martin Comerford
The Transferability Of Force Constants Among Olefins, John Martin Comerford
Theses
A normal coordinate analysis of the in-plane vibrations of ethylene was performed using a modified valence force field, a modified Urey-Bradley force field and a hybrid orbital force field. The B2u species of isobutene was also analyzed. An attempt was made to transfer force constants from ethylene and thereby solve the A1 species of isobutene, but a solution could not be obtained. This suggests that simple transference of force constants is not feasable in this case.
The potential energy distributions obtained for ethylene are discussed. The normal coordinates calculated in this work are appended.
Aiir Pollution Emissions From Turbine Powered Aircraft, Raymond Arthur Filippini
Aiir Pollution Emissions From Turbine Powered Aircraft, Raymond Arthur Filippini
Theses
The major pollutants that are emitted by jet aircraft include: particulate matter (soot), carbon monoxide, aldehydes, hydrocarbons, and nitrogen oxides. The first of the pollutants, particulate matter (smoke), constitutes not only a visual nuisance but is also a potential health problem. The rest, which are not visible, are irritants and in high enough concentrations can be toxic.
Since pollutants emitted by jet aircraft are of the same type as those given off by a car, a direct comparison is possible. In one landing take off cycle (LTO), a four engine jet aircraft emits the same amount of particulate matter as …
The Relation Of Heat Transfer To Power Consumption Of Liquids In Turbulent Flow, John D. Bien
The Relation Of Heat Transfer To Power Consumption Of Liquids In Turbulent Flow, John D. Bien
Theses
The relationship between the heat transfer ability and the power input requirement of liquid coolants in a turbulent heat transfer condition was investigated. A correlation in terms of the liquid physical properties and the required volumetric flow was proposed and the use of this correlation in selection of liquids as coolant was discussed. The optimum condition for a high heat transfer/power input ratio was also discussed.
A Computer Program For The Design Of Packed Extraction Columns, George P. Gaccione
A Computer Program For The Design Of Packed Extraction Columns, George P. Gaccione
Theses
A computer program for the design of packed extraction columns has been developed. This program can operate with a minimum of data of the type that can easily be determined or estimated. The program can be used to investigate design alternates during the preparation of project cost estimates and for the final design of extraction columns.
Viscoelastic Properties Of Polymer Melts, Wu-Shiong Lee
Viscoelastic Properties Of Polymer Melts, Wu-Shiong Lee
Theses
Thirteen samples of molten polymers were used to test Spriggs and Careau Models. Two empirical equations, one for apparent viscosity and the other which is new, for primary normal stress difference, were checked with these samples also.
In order to test the models, material functions were sought for some specific flow patterns under which the experimental data were collected, and then these functions were compared with data.
Careau Model was found to be better than Spriggs Model in representing molten polymer properties but still yield large deviations. Two empirical equations fitted data quite well and were expected to be useful …
Combined Feedforward-Feedback Control Of A Fluidized-Bed Reactor, Reginald Eugene Mitchell
Combined Feedforward-Feedback Control Of A Fluidized-Bed Reactor, Reginald Eugene Mitchell
Theses
Feedforward control, feedback control, and combined feedforward-feedback control were studied on an analog computer to evaluate their effectiveness in controlling a fluidized-bed reactor used for the decomposition of cumene. Proportional, proportional-integral, proportional-derivative, and proportional-integral-derivative modes of control were investigated. Step changes in set-point and load were used as disturbances. The Ziegler-Nichols method and the process reaction curve method of Cohen and Coon were compared in determining values of KC, Ti, and Td which gave optimum control of the fluidized-bed reactor.
Control equation were obtained from the block diagrams of the systems and solved on an EAI TR-20 Analog Computer.
It …
A Modified Redlich-Kwong Equation For Nonpolar And Slightly Polar Gases, David G. Skamenca
A Modified Redlich-Kwong Equation For Nonpolar And Slightly Polar Gases, David G. Skamenca
Theses
The PVT prediction capability of the Redlich-Kwong equation is substantially improved through the use of a generalized correlation based on the acentric factor. No experimental data is required to obtain the improved constants. Only the acentric factor and the critical properties of the pure gas are needed. The correlation of improved constants is limited to non-polar and slightly polar pure gases and mixtures in the supercritical temperature range.
The correlation applies to a reduced temperature range 1.00 le; TR le; 1.60 and a reduced pressure range of 0.030 le; PR le; 3.00. The correlation reduces deviations by as …
Heat And Mass Transfer In The Lyophilizatiuon Of Pharmaceuticals In Vials By Conduction Heating, William Warren Walsh
Heat And Mass Transfer In The Lyophilizatiuon Of Pharmaceuticals In Vials By Conduction Heating, William Warren Walsh
Theses
This thesis investigates the lyophilization of pharmaceuticals in vials by conductive heat transfer. The process phase diagram and methods of determining the solution eutectic temperature are reviewed. The theoretical considerations of heat and mass transfer pertaining to this process are discussed.
Lyophilization tests of distilled water and of mannitol solutions are used to indicate the relationship between vacuum chamber total pressure and the product/vial interface temperature. Experiments with 10% lactose solutions are used to determine the effect of shelf fluid temperature, product height and chamber vacuum on product/vial interface temperature. Test on a pharmaceutical product are used to confirm the …
Correlation And Prediction Of Diffussion Coefficients In Binary Gas Systems, Raymond Gerald Bailey
Correlation And Prediction Of Diffussion Coefficients In Binary Gas Systems, Raymond Gerald Bailey
Theses
A correlation was developed for estimating binary gas diffusion coefficients by the reference substance method, in this case using the viscosity of air and subsequently its corresponding temperature. The derivation was made by the linear least square analysis of 65 different binary systems comprising 161 separate data points at temperatures ranging from 193°K. to 1200°K. At any given temperature only the critical molal volume and the molecular weights of the two gases of interest are required to calculate the diffusion coefficient. The correlation based on the viscosity of air had an average error of 7.67%. The correlation using temperature had …
A Digital Computer Simulation Of A Batch Or Semi-Batch Reactor, Robert Edward Viczorek
A Digital Computer Simulation Of A Batch Or Semi-Batch Reactor, Robert Edward Viczorek
Theses
A digital computer simulation of a batch or semi-batch reaction was developed. The system consisted of a jacketed, agitated vessel equipped with a temperature controller modulating a control valve in the stream to the jacket. The reaction was liquid phase, and the jacket medium was liquid.
The program was written in a general form so as to be applicable to any liquid phase reaction with minimum modification.
A numerical technique was employed using initial values of the process variables in the first cycle of calculations for a time interval, and then using average values for further iterations. The simulation proceeded …
Phosphate Removal From Sewage Using A Combination Of Ferric Chloride And A Polymeric Flocculant, Ravindra C. Patel
Phosphate Removal From Sewage Using A Combination Of Ferric Chloride And A Polymeric Flocculant, Ravindra C. Patel
Theses
The present work is concerned with a newer technique and approach to the problem of phosphate removal from waste water. This includes the removal of phosphate from the sample of activated sludge, i.e., a sample from the aeration tank of the secondary sewage treatment. The phosphate is removed by using ferric chloride as a precipitating agent and a cationic polyelectrolyte (P.E.) as a flocculating agent. Results of this study showed that: (a) P.E. addition gives a significant improvement in phosphate removal over that obtained by ferric chloride alone. In some cases the phosphate removal increased from 92 to 96.5 per …
The Oxidation Of Sulfur Dioxide In A Regenerative Reactor, Raymond Henry Edgecomb
The Oxidation Of Sulfur Dioxide In A Regenerative Reactor, Raymond Henry Edgecomb
Theses
A novel dual-unit sulfuric acid converter is depicted that performs in cyclic operation in unsteady state. A mathematical model and IBM 1130 Computer program were developed to show the temperature and conversion profiles in commercial-sized vanadium oxide catalyst beds. In the catalytic oxidation of sulfur dioxide conversions of 95-97% were attained without benefit of conventional heat exchangers. A single exchanger operating in conjunction with the dual-unit system might attain conversions as high as 99%.
Batch Heat Transfer To Suspensions In An Agitated Vessel, John Philip Horzepa
Batch Heat Transfer To Suspensions In An Agitated Vessel, John Philip Horzepa
Theses
Batch heat transfer data was experimentally determined for two phase (solid?liquid) systems in a baffled agitated vessel. Three iron oxide and water and two kaolin and water suspensions were evaluated and were found to be pseudoplastic. A total of 231 heating and cooling data points were examined. Each suspension was evaluated using anchor, paddle, propeller and turbine impellers. Various sizes of the latter three impellers were used.
The experimental heat transfer results for suspensions were compared with the Hagedorn and Salamone correlation for pseudoplastic liquids. Only partial agreement with the more dilute suspensions was obtained. Overall, the data for suspensions …
Determination Of The Electronic State Of Aryl Nitrenes In An Intramolecular C-H Insertion Reaction, Ali Mohammad Khonsari
Determination Of The Electronic State Of Aryl Nitrenes In An Intramolecular C-H Insertion Reaction, Ali Mohammad Khonsari
Theses
β,γ-Dideuteriopropylbenzene was obtained in 84% yield from deuteration of allylbenzene. Nitration of this compound resulted in o-nitro (β,γ-dideuteriopropyl)-benzene. Reduction of this compound gave o-(β,γ-aideuterio-propyl)aniline. o-(β,γ-Dideuteriopropyl)phenyl azide was prepared by dizotization of the aniline compound, followed by treatment with sodium azide.
Decomposition of the azide in isooctane solution by photolysis at room temperature gave no trace of deuterio-2-methylindoline (intramolecular insertion product).
Photolysis of the azide at the reflux temperature of the solvent (99?C) resulted in the formation of deuterated-2-methylindoline as the major product (40%) yield. The reaction is presumed to proceed through an aryl nitrene intermediate. Analysis of the nuclear magnetic …
A Comparative Analysis Of Multicomponent Distillation Minimum Reflux Methods, Joesph H. F. Loozen
A Comparative Analysis Of Multicomponent Distillation Minimum Reflux Methods, Joesph H. F. Loozen
Theses
One of the most important factors to know in the design of distillation columns is the minimum reflux ratio. Numerous procedures have been developed for the determination of the value of the minimum reflux ratio for multicomponent mixtures requiring various degrees of computational effort. Shortcut techniques are obviously advantageous with respect to computation time. After reviewing the available methods, those by Underwood, Colburn, Scheibel and Montross, Murdoch and Holland, and Shiras et al. were selected for further evaluation, mainly on the basis of practical potential.
Comparison of these procedures was accomplished by calculating the minimum reflux ratio for a large …
An Economic Evaluation Of A Pressure Sulfuric Acid Manufacturing Plant, Daniel A. Marlin
An Economic Evaluation Of A Pressure Sulfuric Acid Manufacturing Plant, Daniel A. Marlin
Theses
The production of Sulfuric Acid at elevated pressures is presented with the economics for operating at one, three, five, seven, nine and thirteen atmospheres. The conventional and pressure plants are compared operating on the same basis.
The basis for a pressure plant design is obtained from an I.B.M. 1130 computer program developed for One Thousand Net Tons per Day of Sulfuric Acid. Recognized operating conditions for a conventional acid plant are incorporated in the pressure plant design program.
Sulfuric Acid manufacture with operating pressures higher than atmospheric, but less than five atmospheres, results in maximum rate of return on investment …
The Optimization Of A Catalytic Methanol Reactor Using Quench Feed, John Paul Mcburney
The Optimization Of A Catalytic Methanol Reactor Using Quench Feed, John Paul Mcburney
Theses
The production of methanol in a catalytic quench feed reactor is studied by means of a computerized model and optimized in terms of total reactor length necessary to achieve a given production rate. The methanol reaction rate can be maximized in a quench reactor through the use of cold stream feeds along the length of reactor.
Since the methanol reaction temperature is restricted to an upper limit of 405°C, the addition of cold stream feed along the adiabatic reactor enables the desired conversion to be reached. For two given levels of conversion, 12% and 15%, an optimum inlet temperature, quench …
A Computer Program For The Optimization Of Binary Distillation In A Dual-Column System, Richard Vincent O'Lenick
A Computer Program For The Optimization Of Binary Distillation In A Dual-Column System, Richard Vincent O'Lenick
Theses
A computer program is presented for the optimization of a two-column distillation system involving a two-component mixture. The economic reflux ratios in each column are determined using the McCabe-Thiele Method. Activity coefficients are computed by either the Wilson equation, the Margules equation, or both. The program is general and may be used for any binary system where the assumption of constant molal overflow is valid.
Options in the program permit use of either column in separate calculation schemes.
While the optimization effort was prepared in general terms, the initial work was directed toward the acetone-water system. Full data for this …
Effect Of Column Diameter On Mixing In Water Fluidized Beds, Donald P. Schiesl
Effect Of Column Diameter On Mixing In Water Fluidized Beds, Donald P. Schiesl
Theses
In this investigation, the effect of column diameter and flow rate on the mixing characteristics of fluidized beds were studied.
Tests were made on columns of 4, 6, 8 and 10 inches in diameter using water to fluidize glass beads of 0.0185 inches in diameter. The tests were run both at minimum and three times minimum fluidization. Step, impulse, and sinusoidal forcing signals were fed to the columns, using a sodium chloride solution as a tracer with the inlet and outlet concentrations being monitored continuously by a conductivity recorder.
The result of this study showed increased fluid dispersion with increasing …
The Effect Of Polymerization Variables On Reaction Rate And Intrinsic Viscosity, David H. Smith
The Effect Of Polymerization Variables On Reaction Rate And Intrinsic Viscosity, David H. Smith
Theses
The free radical solution polymerization of vinyl acetate in benzene was studied under simulated commercial conditions. The effects of monomer, initiator, inhibitor, and chain transfer agent concentration on the reaction rate and intrinsic viscosity were examined. The initial reaction rates with monomer concentrations from 40% to 70% and AIBN concentrations from 0.2% to 0.5% were in agreement with the kinetic equation, - d[M]/dT = K[M]2 [I]1/2. After the initial reaction there was an increase in the reaction rate apparently associated with high viscosities, which is consistent with the Trommsdorff effect. The addition of hundredths of a percent …
The Application Of A Non-Newtonian Rheological Equation To Low-Density Polyethylene, Jeffrey N. Goldstein
The Application Of A Non-Newtonian Rheological Equation To Low-Density Polyethylene, Jeffrey N. Goldstein
Theses
A generalized non-Newtonian equation describing the rheology of molten thermoplastics is verified for low-density polyethylenes. The equation is extended to account for both rheological temperature dependency and polyethylene molecular weight dependency. The prediction of the rheology of new polyethylenes without additional experimentation is thus possible.
Packed Column Simulation, Frederick W. Schmidt
Packed Column Simulation, Frederick W. Schmidt
Theses
The most difficult and time consuming aspect of the design of packed columns is the hydraulic part. If the designer wants to try many different conditions, many repetitive calculations will have to be performed. Also, some inaccuracy is incurred when trying to use the U.S. Stoneware curves. The graphs are hard to read and almost impossible to interpolate between the parametric lines. The purpose of the program is to give a more accurate calculation by using equations for the pressure drop lines, interpolating between them and correcting for gas density for each foot of packing. The program also allows changes …
An Investigation Of A Gas Measurement Technique Employing Ultraviolet Excitation, Alphonso Vincent Diaz
An Investigation Of A Gas Measurement Technique Employing Ultraviolet Excitation, Alphonso Vincent Diaz
Physics Theses & Dissertations
A study was undertaken to determine the general applicability of a temperature measurement technique which uses the fluorescence stimulated by a vacuum ultraviolet continuum as the indicator. This study was directed toward determining the temperature of nonradiating carbon monoxide. A number of ultraviolet radiation sources which produced high intensity in the region of l,150 A were investigated. This study led to the conclusion that the technique was not applicable to measurements in carbon monoxide within the present limits of' detectability.
A Study Of The Reduction Of Nickel Oxide Single Crystal By Hydrogen In A High Vacuum System., Jong In Joung
A Study Of The Reduction Of Nickel Oxide Single Crystal By Hydrogen In A High Vacuum System., Jong In Joung
Chemical and Biological Engineering ETDs
Wafers of well-characterized nickel oxide single crystal, with (110) faces, were etched in hydrochloric acid and reduced by hydrogen in a high vacuum system. Reduction took place at temperatures of 280-310°C and pressures of 1.0-1.3 torr. The reduced wafers were replicated by carbon film and the replicas were examined by an electron microscope.
A series of reduction patterns at various stages of surface change were obtained. After a period of incubation, hemispherical metallic nickel particles, about 400 A in diameter, appeared on the parent nickel oxide surface. The number of hemispheres increased but the size of the hemispheres did not …
Fabrication Of The Pewee Nozzle; Brazing Nozzles For Rockets Powered By Nuclear Reactors, William C. Turner
Fabrication Of The Pewee Nozzle; Brazing Nozzles For Rockets Powered By Nuclear Reactors, William C. Turner
Chemical and Biological Engineering ETDs
This thesis describes the steps taken to develop an improved process for brazing nozzles for nuclear-powered rockets. It defines the state of the art prior to this work. It gives an evaluation of the brazing alloys available for use. It shows the methods employed to develop the use of positive fixturing. It describes the use of full-scale sectors to refine processing. This thesis also describes the use of such new processing techniques in the successful production of two nozzles. Gold-nickel-palladium brazing alloys are used. Vacuum atmosphere performs superbly. Bands are used to hold U-tubes into slots in the shell. Problems …
Fluid Friction Reduction By Water Soluble Linear High Polymers, Arthur Edward Davis
Fluid Friction Reduction By Water Soluble Linear High Polymers, Arthur Edward Davis
Theses
The effects of various dilute aqueous linear high polymer solutions on turbulent pipe flow were studied to determine the polymer most suitable for testing as the drag reducing component in the proposed coating. Results of this study are presented for commercial schedule 40 1/4 inch NPS black iron pipe. Tests were conducted at Reynolds numbers of 6.2x104,8.3x104 and 9.8x104.
Attempts were made to prepare a coating containing a friction drag reducing polymer - Polyhall 295 polyacrylamide - utilizing various techniques of polymer incorporation into the paint including several grinding and dispersion methods, adding the polymer …
Binary Molecular Diffusivities In Liquids: Prediction And Comparison With Experimental Data, Ronald Dean Mitchell
Binary Molecular Diffusivities In Liquids: Prediction And Comparison With Experimental Data, Ronald Dean Mitchell
Doctoral Dissertations
"The Eyring rate theory equation has been modified successfully to enable predictions of binary molecular diffusivities for a wide variety of liquid-liquid systems. The activation free energy for binary diffusion has been evaluated in terms of the activation free energies for self diffusion of the solvent and solute. This was accomplished through the use of regular solution theory by relating the bond breaking energy of the jump step to the bond breaking energy in evaporation. Diffusivities estimated by this equation and the equations developed by Olander, by Gainer and Metzner, and by Wilke and Chang were compared with experimental data. …
An Sem Surface Study Of Nucleate Pool Boiling Heat Transfer To Saturated Liquid Nitrogen Reduced Pressures From 0.1 To 0.9, David Virgil Porchey
An Sem Surface Study Of Nucleate Pool Boiling Heat Transfer To Saturated Liquid Nitrogen Reduced Pressures From 0.1 To 0.9, David Virgil Porchey
Doctoral Dissertations
"This study constituted an examination of both nucleate boiling and maximum heat flux characteristics of liquid nitrogen boiling from characterized surfaces. Several textures of gold plated copper surfaces were studied in addition to silver and silver oxide surfaces. Data were taken over a wide range of reduced pressures. All surfaces were examined using a Scanning Electron Microscope (SEM). Data and micrograph comparison revealed that both surface chemistry and surface roughness affect the nucleate boiling characteristics of liquid nitrogen. These effects are separated from each other showing that nucleate boiling is a function of both surface chemistry and topography. Surface roughness …
A Three-Dimensional Mathematical Simulator Of Multiphase Systems In A Petroleum Reservoir, Leonard Koederitz
A Three-Dimensional Mathematical Simulator Of Multiphase Systems In A Petroleum Reservoir, Leonard Koederitz
Doctoral Dissertations
"A generalized digital analysis for calculating three phase, three dimensional flow in reservoirs is developed. The computerized mathematical model is applicable to depletion drive, gas injection, water injection, and/or aquifer drive systems with modifications specific to the simulation criterion of that type of drive and includes fluid compressibility effects, gravity drainage and capillary pressure. The simulation allows arbitrary consideration of reservoir heterogeneity, geometry, well locations and rates of production. An innovation to the alternating direction technique for linear differential equations discussed by Brian is developed and employed in order to render the method of solution applicable to non-linear differential equations. …
Anodic Dissolution Of Zinc In Potassium Iodide-Potassium Iodate Solutions, Chi-Chiu Yao
Anodic Dissolution Of Zinc In Potassium Iodide-Potassium Iodate Solutions, Chi-Chiu Yao
Doctoral Dissertations
"The anodic dissolution of Zn was studied in KI-KIO₃ solutions at 25ºC. In I⁻ solutions, it was found that the apparent valence of Zn ions going into solution is approximately two. Smaller values are obtained in IO₃⁻ solutions, with the most pronounced changes occurring in the higher concentrations. An empirical equation is derived relating the apparent valence (or anode efficiency) to the current density and concentrations of IO₃⁻ and I⁻. An anodic dissolution mechanism is proposed"--Abstract, page 1.