Engineering Commons^™

Turbulence Measurements In Polymer Solutions Using Hot-Film Anemometry, Gary Kent Patterson

Doctoral Dissertations

"Hot-film anemometry was used to study the detailed structure of turbulence (intensities, energy spectra, and auto-correlations) in Newtonian solvents, non-drag reducing polymer solutions, and drag reducing polymer solutions. This was done in two smooth wall tubes with diameters of 1.0 inch and 2.0 inches. A probe traversing mechanism was used for measurements at radial positions from the center to as near the wall as possible for both the film probes (r/a=0.85 in the 2-inch tube) and the impact tubes (r/ a=0.98). The impact tubes were used to measure velocities for film probe calibration.

The solvents used in this investigation were …

Permeability And Additive Sorption And Extraction In Lubricating Greases, Hsiu-Hsiung Lin

Masters Theses

"An important goal in the study of lubricating greases is the determination of the mechanism of additive action in lubricating greases and the effect of additive concentration on the improvement of particular properties. As a step in this direction, one aim of this investigation was an attempt to determine whether grease additives are sorbed on the thickener surface, or are dissolved in the oil phase, or if a combination of these effects prevails. Exploratory sorption and extraction experiments were run by Tu using greases thickened with lithium hydroxystearate and Baragel and using only one concentration of additive. More detailed studies …

The Kinetics Of The Reaction Of M-Nitrobenzyl Bromide With Hydroxide Ion In Aqueous-Aprotic Solvent Mixtures, Ramesh Nagindas Sheth

Masters Theses

"The reaction between m-nitrobenzyl bromide and sodium hydroxide in homogeneous aqueous dioxane and aqueous tetrahydrofuran media was studied.

The product of the reaction was identified by infrared, gas chromatography and chemical tests as m-nitrobenzyl alcohol.
The kinetics of the reaction are second order with practically no variation in the rate constants as the % of the organic solvent was changed in the medium. This seems to imply hydrolysis of the organic halide by a process involving both bond-breaking and bond-formation in the transition state.
The activation energy, measured in 50% aqueous dioxane, between 20⁰ and 69.5⁰C at 5 different temperatures, …

Kinetics And Mechanisms Of Base-Catalysed Reactions, Rohit Panalal Sheth

Masters Theses

"Base-catalysed reactions normally involve complex series of transformations. their kinetics is usually governed by a variety of equilibria, participating in the overall and concurrent processes as well as by competitive side-reactions that interfere with the normal course of such reactions. Mechanisms which have been proposed, by and large, are primarily based on product, by-product and intermediate analyses together with some scattered kinetic and isotopic evidence. In the cases where kinetic studies have been attempted, highly complex mechanisms have usually been proposed due to the frequent necessity of using heterogeneous media or employing involved mathematical treatments to describe the kinetics of …

Decarboxylation Of Malonic Acid In Aqueous Solutions, Ramesh Natwarlal Gujarathi

Masters Theses

"The rate of decarboxylation of malonic acid in aqueous solutions was studied over a range of concentrations, pH's, and temperatures. The catalytic effect of various divalent metallic ions was also studied at a pH of 0.3. these studies did not support a truly unimolecular decomposition as the experimental order was found to be slightly greater than one. An empirical relation for the rate of decarboxylation was formulated in which the undissociated malonic acid and the monovalent malonate ion were the reactive species.

A possible mechanism of decarboxylation due to solvent activation was postulated. No pronounced catalytic effect due to the …

Mass Transfer In Droplets With Turbulent Internal Circulation - Mathematical Description, Jayantilal Mohanbhai Patel

Masters Theses

"This investigation was carried out to check the accuracy of the eigenvalues, λ_n, calculated by Wellek and Skelland, using some method other than the Rayleigh-Ritz technique and also, to determine the coefficients, B_n in series solution, which were not calculated before.
The eigenvalues were obtained by trial and error procedure using the standard Runge-Kutta method. The coefficients B_n were obtained by using eigenvalues. By using this information the fractional extraction was calculated as a function of droplet contact time.

The Wellek-Skelland modification was also solved by finite difference technique to compute fraction extracted as a function …

A Study Of Molecular Diffusion In Polymer Solutions By A Microinterferometric Method, Girish T. Dalal

Masters Theses

"A microinterferometric method was used to study the effect of solute concentration on the diffusion coefficient in polymer solutions and also to determine the effect of polymer concentration on the diffusion coefficient. The polyacrylonitrile-dimethylformamide system was used as a means of determining the accuracy of the experimental apparatus and procedure. The non-ionic, water soluble polymer, hydroxyethyl cellulose (commercially known as Natrosol), was used to study this effect with urea and D-glucose as the solutes.

The results obtained for the polyacrylonitrile-dimethylformamide system were in close agreement with the results obtained by Secor, which meant that the experimental technique is accurate enough …

The Anodic Oxidation Of Maleic Acid, Larry D. Gilmartin

Masters Theses

"The purpose of this investigation was to determine the mechanism of the anodic oxidation of maleic acid on platinized-platinum electrodes at 80⁰C. Current density-potential studies were conducted varying the parameters of maleic acid concentration and pH. The faradaic efficiency of the oxidation of maleic acid to yield CO₂ was determined. The effect of temperature on current density was also studied to determine the activation energy for the reaction. The oxidation of maleic acid occurred only in acidic solutions. The faradaic efficiency was found to be approximately 97 ± 5 per cent. A linear Tafel region was found which had a …

The Anodic Dissolution Of Magnesium In Aqueous Solutions, Chen-I Lu

Masters Theses

"The anodic dissolution of magnesium was studied in MgCl₂-KC1 and MgBr₂-KBr mixtures at 25, 40, and 55 °C. The parameters of the study were current density, concentration of magnesium ion, and temperature. The concentration of magnesium ions was varied from 0.001 to 1 N holding the ionic strength constant at 1.5. The weight loss of magnesium from the electrode during electrolysis was determined by weighing the electrode both before and after electrolysis. The current was measured with a sensitive milliammeter. The range of the current densities was varied from 0.001 to 0.1 amps·cm^-2. The …

Anodic Dissolution Of Silver In Aqueous Solutions, B. W. Jong

Masters Theses

"The purpose of this investigation was to study the anodic dissolution of silver in various electrolytes to determine if there existed any deviations from Faraday’s law in nitric acid-silver nitrate solutions. The effect of small additions (10^-4 and 10^-5 N) of Cl^-, SO₄⁼, and CrO₄⁼ on the apparent valence and dissolution potential was also studied. Current densities were varied from 0.00 to 0.07 amp·cm^-2.

Based on the observed apparent valences and a grey film containing metallic particles on the anode surface, it was concluded that deviations from Faraday’s law …

A Study Of The Removal Of Alkyl Benzene Sulfonate By Means Of A Column Packed With Sand Coated With Ferric Oxide, Chang I. Fung

Masters Theses

"Iron, precipitated in the form of hydroxides on sand particles (-48 + 65 mesh) and stabilized by drying at 100°C for 10 hours, was utilized to remove alkyl benzene sulfonate (ABS) from aqueous solutions. Solutions containing a maximum of 5 mg/l ABS were passed through a glass column packed with treated sand. The ABS formed a complex with the iron precipitants which adhered to the sand particles.

Preliminary work, in which solutions containing 10 mg/l ABS were treated with various concentrations of FeCl₂ at the equivalence point (pH about 9.5), verified the fact that ABS could be removed by …

A Crystallographic Study Of The Pbzro₃-Pbtio₃-Bifeo₃ Ternary System., Dannie R. Clarida

Masters Theses

"The purpose of this investigation was to conduct a crystallographic study of the PbZrO₃-PbTiO₃-BiFeO₃ ternary system, where all three components are perovskites. Lead zirconate is antiferroelectric, lead titanate is ferroelectric, and bismuth ferrate is thought to be ferroelectric. X-ray diffraction analysis was employed to determine the crystallographic structure and lattice parameters.

A tetragonal region was found to exist in the area of high PbTiO₃ content. A rhombohedral region occurred in the remainder of the system with high BiFeO₃ and PbZrO₃ content, except for an orthorhombic envelope along the PbZrO₃-BiFeO₃ side of the diagram up to approximately 70 per cent BiFeO₃.The …

Anodic Dissolution Of Lead In Aqueous Solutions, Christopher Kuo-Chieh Wu

Masters Theses

"The apparent valence of lead was determined in one normal solutions of potassium nitrate, ammonium acetate, lead nitrate, and lead acetate at temperatures of 25 and 50°C. The current density was varied from 0.001 to 1.00 amp•cm ^-2. The apparent valence of lead ranged between 1.90 and 2.00 in all solutions. The lower valences were reached at higher current densities. The amount of disintegration was very small, and was dependent upon film formation on the surface of the anode.

Potential-current density relationships for the anodic dissolution of lead were obtained in the electrolytes mentioned above. In potassium nitrate and …

Study Of Mass Transfer Through Porous, Water-Repellent Membranes, Virendra V. Tanna

Masters Theses

"A new method of desalination using a porous, water-repellent membrane was studied. The membrane utilized surface forces to support a vapor phase in its pores which separated the salt water from fresh water. The method used a vapor pressure difference across the membrane as the driving force for mass transfer of water from the salt water phase to the fresh water. This vapor pressure difference was obtained by maintaining a temperature difference between the two liquid phases.

The experimental data and results indicated the feasibility of vaporization through porous, water-repellent membranes. The flux of water through a membrane made of …

Study Of Heat And Mass Transfer Through Non-Wettable Porous Membrane, Rajender Kumar Rohatgi

Masters Theses

"The object of this investigation was to study the use of non-wettable porous membranes for simultaneous heat transfer and mass transfer of water from a hot salt solution stream to a cold distilled water stream, the streams being in countercurrent flow separated by the membrane. This type of mass transfer was achieved in the experiments, and mass and heat transfer coefficients were measured.

The membranes studied in this work were made of fiberglas treated with Teflon dispersion and aluminum sulphate. The fiberglas membranes yielded desired results. Empirical correlations were proposed which predict values of heat and mass transfer coefficients close …

The Performance Of A Countercurrent Extraction Column With Vibrated Packing, Mehmet Uran ÖZsoy

Masters Theses

"The performance of a continuous countercurrent extraction column with a packing -- that could be vibrated vertically at various amplitudes and frequencies by a variable speed motor -- was investigated under both non-flooding and flooding conditions using the high interfacial tension benzene-acetic acid-water ternary system. In all the experimental runs, which were sequenced randomly with a full-factorial experiment design, mass transfer of the solute (acetic acid) from the aqueous to the organic phase was studied. Column performance was evaluated in terms of the height of an overall transfer unit, HTU, based on the benzene phase. The variables studied were: amplitude …

Correlation Of Drag Reducing Data In Dilute Polymer Solutions, Jorge Mario Rodriguez

Masters Theses

"The purpose of this investigation was to obtain a correlation for drag reducing solutions in circular tubes under turbulent conditions. Data were taken for three polymer-solvent systems: polymethyl methacrylate V-100 (M_v ~ 110,000) in toluene, polyisobutylene L-200 (M_v ~ 4,700,000) in toluene, and polyisobutylene L-200 in cyclohexane. The data from the two polyisobutylene systems, together with other data on polymethyl methacrylate G (M_v ~ 1,500,000) in toluene and polyisobutylene L-80 (M_v ~ 860,000) in cyclohexane, were used to attempt to obtain the correlation. The V-100 solutions were not used because they were not drag reducing.

The …

The Effect Of Concentration On The Viscosity Of Polyisobutylene Solutions, Lung-Yu Chou

Masters Theses

"In the past twenty years the viscosity of dilute polymer solutions (i.e., where the solute molecules are far apart) has been investigated in great detail, both theoretically and experimentally. The viscosity characteristics of such systems are well-understood.

Only a few studies have been made of the effect of concentration on the viscosity of polymer solutions in the concentration range where the polymer molecules begin to overlap. This range of concentrations is important in practical applications such as dry spinning of fibers, cross-graded automotive motor oils and in many industrial formulations where polymers are used to thicken solvent vehicles. Development of …

The Anodic Oxidation Of Crotonic Acid In Basic Solutions, Richard C. Porter

Masters Theses

"The purpose of this study was to investigate the anodic oxidation of crotonic acid in basic solutions. Potassium hydroxide solutions of pH 12.3 and KOH-K₂CO₃ solutions of pH 11.5 and 10.5 were used. The investigation was carried out on platinized-platinum anodes at 80°C.

Experimental studies were conducted to determine the effects of crotonic acid concentration, pH, and temperature on the current. Faradaic efficiency was determined by analysis of CO₂ produced and was approximately 100 per cent.

The results were interpreted in terms of a mechanism having the following characteristics:

1. The first electron transfer is the rate …

The Anodic Dissolution Of Cadmium In Aqueous Solutions, San-Cheng Lai

Doctoral Dissertations

"The purpose of this investigation was to study the effect of cadmium ions on the anodic dissolution of cadmium in salt solutions of ·constant ionic strength. The concentration of the cadmium ions was varied from 0.001 to 1 N and the current density ranged from 0.001 to 0.1 amp•cm^-2. The temperature was controlled at 25°C.

....A mathematical model was postulated expressing the anodic dissolution rate as the sum of electrochemical, local corrosion, and disintegration rates."--Abstract, page iii.

A Study Of The Anodic Oxidation Of Acetylene On Gold Electrodes, Jo Lisle Reed

Doctoral Dissertations

"The object of this investigation was to establish a mechanism for the anodic oxidation of acetylene on gold electrodes in aqueous solutions. It is known that anodic oxidation of organic compounds on gold electrodes produces a large number of organic intermediates and end products. Therefore, it appeared worthwhile to establish a mechanism that could provide a better understanding of the fuel cell electrode kinetics and possibly lead to new methods of organic syntheses"--Introduction, page 2.

Aeration Studies In Submerged Fermentations Using A Steam-Sterilizable Dissolved Oxygen Sensor Of Improved Design, Carl J. Wallace

Doctoral Dissertations

"Large-scale submerged fermentations have been important for many years for the production of antibiotics, vitamins, enzymes, etc.; however, aeration studies have been severely restricted in these processes because of the unavailability of adequate oxygen sensing equipment.

A steam-sterilizable oxygen sensor of improved design was developed out of an investigation of several potential sensors. This rapidly responding galvanic probe made use of a lead anode, a silver cathode, an acetate buffer as the electrolyte, and a one mil Teflon® membrane as the diffusion barrier. Its sensitivity was approximately 40 µamps and full response required approximately 5 minutes.

Use was made of …

Prediction Of Batch Heat Transfer Coefficients For Pseudoplastic Fluids In Agitated Vessels, Donald William Hagedorn

Dissertations

Experimental batch heat-transfer data were obtained for both Newtonian and pseudoplastic liquids in a baffled agitated vessel. The fluids tested had flow behavior in-dexes between 0.36 and 1.0; and the apparent viscosity ranged from 1 to 1200 centipoise. Four types of impellers (anchor, paddle, propeller, and disk and vane turbine) were studied using eleven separate impellers. The probable error in the measured heat transfer coefficient was ± 20 percent.

The effects of the generalized Reynolds number, generalized Prandtl number, and viscosity ratio were studied. In addition the effect of impeller diameter was studied for paddles, propellers, and turbines; and the …

The Electrochemical Oxidation Of Cholesteryl Acetate Dibromide, Abraham Cooper

Dissertations

Cholesteryl Acetate Dibromide was dissolved in carbon tetrachloride, suspended with mixing in 4.5 molar solution of sulfuric acid and electrolyzed at a lead dioxide anode. The anodically prepared film of lead dioxide, when maintained at potentials (relative to a calomel electrode) above 1.5 volts, was a catalyst for the oxidation. A new and mild oxidation took place at the catalytic electrode surface that resulted in attack on the tertiary hydrogen atom at the 25 carbon. The mildness of the oxidation prevented the decomposition of the unconverted raw material and permitted the recovery of up to 96% of the cholesteryl acetate …

Current-Potential Effects Of Trace Impurities In Manganese Electrowinning, George Robert Ferment

Dissertations

The purpose of this investigation was to study the effects of trace metallic impurities, found in manganese electro-winning solutions, on cathode current-potential curves.

This investigation led to the development of a novel analytical tool, emphasizing polarization curves as a means of detecting trace metallic impurities in manganese sulfate electrolytes. The method possesses two distinguishing features: (a) it uses the competing hydrogen evolution reaction as a means of detecting metallic impurities, and (b) it enables one to establish if the electrolyte is sufficiently pure for efficient electrolysis.

Nine metallic impurities were studied, consisting of: nickel, cobalt, silver, copper, zinc, molybdenum, cadmium, …

Effect Of Particle Size And Particle Size Distribution On The Burning Rate Of Barium Chromate-Boron Pyrotechnic Delay Compositions, Donald J. Freeman

Theses

The burning rate of barium chromate-boron delay compositions is shown to be related to the 10 percent particle size point on the particle size distribution curve (particle size vs. percent greater than size) for either of the components. The burning rate is also shown to be inversely proportional to the 10 percent point of the barium chromate; and to follow a hyperbolic type relationship with the 10 percent of the boron, decreasing asymptotically as the 10 percent point increases. No correlations were found between the burning rate of the compositions and the average particle diameter, the mean particle diameter, or …

Investigation Of The Octene-Decane-Urea Adduct Equilibrium System, Frederick Charles Guest

Theses

Concentrations of equilibrium mixtures formed by adding increments of octene to a solution of urea in methanol to form adduct are reported.

Calorimetric studies indicate that the addition of octene to a urea-methanol solution shows an endothermic heat effect prior to the formation of solid adduct. The heat effect becomes exothermic as solid adduct is formed.

Addition of decane to an equilibrium octene-urea adduct system increased octene concentration in the supernatent liquid, indicating an octene release from the original adduct as decane adduct was formed.

The order in which decane and octene were added to form the decane-octene-urea adduct system …

Cation Exchange Between Solutions Of Ferric Nitrate And Dowex 50x-8 Resin, Michael H. Mansky

Theses

The rate of exchange of ferric ions from solutions of ferric nitrate and hydrogen ions from Dowex 50X-8 has been studied in an agitated bed ion exchange column over a range of bed loading conditions. Agitation has been maintained in a regime known to indicate film diffusion control of rate in small scale batch reactors.

Calculated diffusion coefficients for the column are slightly higher than those determined in the batch reactor because of greater turbulence of agitation in the column.

The assumption of previous investigators concerning linearity of equilibrium data has been found to be invalid for the system studied. …

Factors Affecting The Biodegradation Of Linear Alkylbenzene Sulfonates In River Die-Away Studies, Neil M. Mchugh

Theses

The determining factors in the biodegradation of linear alkylbenzene sulfonates have been investigated using the river die-away technique. Emphasis was placed on finding the correlation between biodegradability and each of the following: surfactant structure, inoculation of basic water medium with activated sludge, and acclimation of bacteria to a given surfactant. It has been shown that the lower the molecular weight of linear alkylate, down to C8, the faster the rate of biodegradation. It was further shown that there is no direct relationship between phenyl position distribution and biodegradability, nor is there any direct correlation between the amount of surfactant remaining …

Use Of Gas Chromatography To Determine The Mutual Solubility Of Water And Toluene, John Orshich

Theses

The possibility of determining the water traces in water saturated toluene as well as the traces of toluene in toluene saturated water by means of gas chromatography was investigated.

A 15 feet long, 1/4 inch copper column, attached to F & M Chromatograph 500, was used; the column was packed with 5 Armeen SB on Haloport F (Teflon).

The determination of toluene in toluene saturated water did not appear to be feasible, since the retention time for toluene with the used column was too short to allow the base line of the recorder to become steady at the attenuation value …