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Articles 74131 - 74160 of 77343

Full-Text Articles in Engineering

Compressive Creep Of Basic Refractories, Maurice E. Green Jan 1968

Compressive Creep Of Basic Refractories, Maurice E. Green

Masters Theses

"The microstructure and mineralogical composition of direct bonded, 50 wt.% magnesia - 50 wt.% chrome ore refractory compositions containing controlled additions of silica were correlated with their compressive creep behavior in the temperature range 1450⁰ to 1550⁰C under stresses of 100 to 175 psi. Steady state creep rates were determined from the linear regression of the steady state regions of deformation on time. Apparent activation energies and deformation flow characteristics were determined from the temperature and stress dependence of the steady state creep rates. Silica contents up to 3.5 wt.% increased the amount of direct intergranular bonding which decreased the …

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Spacing Of Explosive Charges, Calvin J. Konya Jan 1968

Spacing Of Explosive Charges, Calvin J. Konya

Masters Theses

"It is generally believed that the spacing of simultaneously initiated collar primed multiple charges is not dependent on the charge length. The stresses generated by explosive charges have been assumed to propagate through a material in a cylindrical manner. this assumption implied that the stress generated in any plane along the charge diameter would have been uniform in magnitude and direction. A finite explosive velocity along with a conical stress wave causes the stresses near the collar to differ from those farther down the column. for this reason, the spacing of charges would be dependent on charge length. An experimental …

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Thermal Runaway In Power Transistors, Jerry H. Lee Jan 1968

Thermal Runaway In Power Transistors, Jerry H. Lee

Masters Theses

"Considerable work has been done on the theory of thermal runaway and the relationship between transistor junction temperature and collector power dissipation. The first part of this thesis is a review of literature. An equation for the normalized junction temperature and its peak value is developed. From this equation, the junction temperature at the thermal runaway point for a given maximum power dissipation could be determined. The second part of this thesis is experimental. The author examined the thermal runaway points for eight different transistors in the basic common emitter class A circuit which operated under no signal DC conditions"--Abstract, …

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Radiation And Annealing Characteristics In Neutron Bombarded Transistors Operated In The Inverse Configuration, Lo-Soun Su Jan 1968

Radiation And Annealing Characteristics In Neutron Bombarded Transistors Operated In The Inverse Configuration, Lo-Soun Su

Masters Theses

"When operating a silicon planar epitaxial transistor in the inverse configuration (i.e., with the emitter functioning as a collector and the collector functioning an emitter) the bulk space-charge volume of the new "emitter-base" junction is increased by a factor of 26.5 times that of the normal emitter-base junction. The carrier concentration in the new "emitter" is decreased by five orders of magnitude from that of the normal emitter, thus making it easier to investigate the effects of neutron radiation on the space-charge region and at the surface. Experiments using biasing of the new "emitter-base" junction during neutron radiation to change …

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An Intragastric Ph And Motility Monitoring And Automatic Titration System, Barry Foster Maycock Jan 1968

An Intragastric Ph And Motility Monitoring And Automatic Titration System, Barry Foster Maycock

Masters Theses

"Knowledge of the effects of prolonged states of weightlessness on the physiological activities of gastric motility and acid secretion will aid in the planning of future space flights, since aberrations in these activities could affect the performance of astronauts. Investigation of these activities requires monitoring of the pressure and pH in the stomach and titration of the gastric contents. Since previous methods and equipment used for performing these functions are inadequate for this investigation, the equipment whose design and operation are discussed in this thesis was developed. This equipment includes an ingestible sensor capsule which is tethered in the stomach, …

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The Decomposition Of 5-Hydroxymethyl-2-Furaldehyde Under Gamma Irradiation, William George Bowles Jan 1968

The Decomposition Of 5-Hydroxymethyl-2-Furaldehyde Under Gamma Irradiation, William George Bowles

Masters Theses

"An investigation into the effects of gamma irradiation decomposition of 5-hydroxymethyl-2-furaldehyde (HMF) revealed HMF to be resistant to radiation catalyzed decomposition. A 1.0 normal solution of HMF was irradiated at a dose rate of 4.1 x 10⁵ Rads/hr to a total dose of 8.2 x 10⁶ Rads from a 5000 Curie ⁶⁰Co source. a total of 31 per cent of the HMF decomposed in a zero order reaction, although it was found the HMF decomposed completely under cadmium shielded irradiation in a nuclear reactor with some neutrons present. The reaction rate constant was found to be 4.8 x 10⁻³ moles …

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Fast Neutron Induced Resistivity Changes In Order-Disorder Fe₃Al, Bruce A. Betts Jan 1968

Fast Neutron Induced Resistivity Changes In Order-Disorder Fe₃Al, Bruce A. Betts

Masters Theses

"Resistivity measurements were made of ordered, disordered and intermediate states of order-disordered specimens of Fe₃Al while being irradiated by neutrons. All the specimens were irradiated at ambient temperature, approximately 35°C in a modified Bulk Shielding Swimming Pool type reactor. The ordered and near ordered specimens increased in resistivity indicating disordering whereas the disordered and near disordered specimens decreased in resistivity indicating an ordering process was occuring [sic]. By extrapolation, an equilibrium condition was determined and estimated at 130-135 micro-ohms-cm resistivity that would remain constant during irradiation because the ordering and disordering affects of neutron irradiation would be in equilibrium"--Abstract, page …

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Instrumentation Of A Shock Tube Facility, James Everett West Jan 1968

Instrumentation Of A Shock Tube Facility, James Everett West

Masters Theses

"The theory of schlieren and interferometer systems was described and related to studies of shock waves in a shock tube. An interferometer was procured and a schlieren system was modified for use with the UMR shock tube facility. The design and construction of a base for the systems and window assemblies for the shock tube comprised the major portion of the work on this project. A short series of tests were run to ascertain the compatibility of the instrumentation to the UMR shock tube facility. While no schlieren photograph of the shock wave was obtained, the system was shown to …

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The Effect Of Prior Cold Work On The Pressure Welding Of Ferritic Nodular Iron, Ronald Morris Ledbetter Jan 1968

The Effect Of Prior Cold Work On The Pressure Welding Of Ferritic Nodular Iron, Ronald Morris Ledbetter

Masters Theses

"The purpose of this investigation was to determine the effect of prior cold work by swaging on the pressure welding of ferritic nodular iron. Test pressure welds were produced from continuously cast ferritic nodular iron in the as cast condition and with prior cold work of 20, 30, 40, and 50 per cent reductions in area. Welding pressures of 23,500 psi, 35,300 psi, and 47,100 psi were employed. All welds were made at interface temperatures of 2000°F. Welds made with the as cast material at high welding pressures possessed relatively low tensile strengths due to the creation of planes of …

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Computer Simulation Of Scraper-Pusher Behavior During Early Open Pit Mining Operations, Martin Alan Thieme Jan 1968

Computer Simulation Of Scraper-Pusher Behavior During Early Open Pit Mining Operations, Martin Alan Thieme

Masters Theses

"A method has been developed for study and evaluation of overburden removal systems in open pit mining. The computer simulation method shows the effect of vehicle and course characteristics and the control of loading time on overall production and cost per unit of overburden removed. Data are available from vehicle manufacturers and from past mining experience. The data are punched onto processing cards and the system is then simulated and analyzed using a digital computer. The products of the system simulation consist of a tabulated listing of all control variables after each simulated vehicle loading and a system summary predicting …

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Radar Waveform Synthesis By Mean-Square Optimization Techniques, John D. Wolf Jan 1968

Radar Waveform Synthesis By Mean-Square Optimization Techniques, John D. Wolf

Masters Theses

"The ambiguity function is derived and its properties useful to radar waveform analysis are investigated. Synthesis of the phase-modulated waveform whose ambiguity function is the minimum mean-square estimate of some desired ambiguity function is accomplished by expanding the phase modulation function in an orthogonal series. The ambiguity function, defined as a magnitude, and the value of an arbitrary cost functional defined on the ([tau],wd) plane is then expressed in terms of the coefficients of the orthogonal series. thus, the "optimum" waveform can be determined by solving the variational equations for the coefficients. Numerical examples are presented for the …

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Design And Construction Of A Liquid Nitrogen Cryostat For Use In A Swimming Pool Type Reactor, Bruce B. Joiner Jan 1968

Design And Construction Of A Liquid Nitrogen Cryostat For Use In A Swimming Pool Type Reactor, Bruce B. Joiner

Masters Theses

"The continued expansion of the nuclear reactor facility and the nuclear engineering program dictates the need that a liquid nitrogen cooled cryostat be available at the reactor. This unit would be available for use in graduate and undergraduate laboratories and for graduate research. A liquid nitrogen cooled cryostat capable of maintaining a sample between 77°K to 80°K for an extended period of time in or adjacent to the core of the reactor was designed, constructed, and successfully operated. Recommendations were made for possible modifications to expand the versatility of the system"--Abstract, page ii.

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Evaluation And Application Of Dye Tracing In A Karst Terrain, James William Scanlan Jan 1968

Evaluation And Application Of Dye Tracing In A Karst Terrain, James William Scanlan

Masters Theses

"The purpose of this investigation was to select and evaluate in the laboratory a tracing method appropriate for use in karstic areas, and to perform field tracing studies in the south central Missouri area bounded by the cities of Rolla, St. James, and Salem in an attempt to establish existing direct flow connections between surface and subsurface waters. Fluorescein (sodium salt), Rhodamine WT, and Rhodamine B were evaluated as tracers in the laboratory and the first two dyes were employed in the field. After careful evaluation of a number of adsorbents, extracting solvents, and detection techniques, a method consisting of …

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Lattice Parameters, Coefficients Of Thermal Expansion, Densities, And Lattice Perfection Of The Copper-Indium Primary Solid Solutions, Lin Sheng Yu Jan 1968

Lattice Parameters, Coefficients Of Thermal Expansion, Densities, And Lattice Perfection Of The Copper-Indium Primary Solid Solutions, Lin Sheng Yu

Masters Theses

"Precise measurements of lattice parameters and densities of the alpha-phase Cu-In solid solutions were made at temperatures of 25°C. The thermal expansion coefficients between 15 and 65°C, the solid solubility of In in Cu at 650°C, and the soundness of crystal structure resulting from alloying were determined. The Cu-In alloys were prepared from high purity (99.999%) Cu and In by melting both metals inside evacuated quartz tubes. The solidified alloys were annealed and then examined by X-ray for homogeneity...The slowly solidified alpha-phase alloys gave densities lower than the theoretical (X-ray) values due to the presence of shrinkage microporosity. This density …

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Diffusion Coefficients Of D-Glucose In Aqueous Carboxymethylcellulose And Carboxypolymethylene Solutions, Audrey Liu-Mei Huang Jan 1968

Diffusion Coefficients Of D-Glucose In Aqueous Carboxymethylcellulose And Carboxypolymethylene Solutions, Audrey Liu-Mei Huang

Masters Theses

"A microinterferometric method was used to determine the concentration profiles in the infinite field unsteady state diffusion of D-Glucose in aqueous polymer solutions. Pseudo binary diffusion coefficients were determined as a function of reduced concentration both with and without the effect of liquid volume change during diffusion being considered. The systems studied were D-Glucose in aqueous Carboxymethylcellulose and D-Glucose in aqueous Carboxypolymethylene solutions. Solute concentration ranged from nearly zero to about 9% by weight D-Glucose in the aqueous polymer solutions"--Abstract, page ii.

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Coupled Transport Of Heat And Mass In Laminar Tube Flow, Lung-Mau Huang Jan 1968

Coupled Transport Of Heat And Mass In Laminar Tube Flow, Lung-Mau Huang

Masters Theses

"The object of this investigation is to study the mutual dependence of heat and mass transport in laminar and hydrodynamically developed tube flow. Consideration is given to gas flow through a tube whose wall is coated with a sublimable materials so that heat and mass transfers take place between the wall and the flowing gas stream. The tube wall is thermally insulated from the external environment, with the result that the latent heat required by the sublimation process at the wall is supplied solely by convective transfer from the gas. The analysis of the problem requires simultaneous solution of the …

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Numerical Integration Of Shell Equations Using The Field Method, Pravin R. Ghael Jan 1968

Numerical Integration Of Shell Equations Using The Field Method, Pravin R. Ghael

Masters Theses

"In this work field equations are introduced to numerically solve the six linear differential equations which determine the displacements and stress resultants for thin elastic shells with axially symmetric loadings. With the applications of the field equations to the analysis of symmetric shells, the two-point boundary-value problem is formulated in terms of twelve first-order ordinary differential equations with boundary conditions at only one point. These equations are solved by using a forth [sic]-order Runge_kutta integration formula. Three problems whose solutions are known have been evaluated to check the accuracy of the field equation method. These are: (1.) Simply-supported, thin circular …

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The Effects Of Grinding On The Physical Properties Of Clay Soils, Thomas Michael Mcmillen Jan 1968

The Effects Of Grinding On The Physical Properties Of Clay Soils, Thomas Michael Mcmillen

Masters Theses

"Studies of the effect of grinding on clay soils are summarized. Fundamental aspects of thixotropic phenomena are also explored. Vetters clay and Lebanon silt loam are used as test soils. these soils are ground to varying degrees and the deviations in physical properties are determined. Atterberg Limits, specific gravity, grain size, X-ray diffraction, and D.T.A. tests are run on each soil batch (ground for 0 minutes, 30 minutes, 60 minutes, and 120 minutes). A thixotropic study, consisting of unconfined compression and laboratory vane shear tests, of each soil batch is made. The results of the tests are analyzed, compared, and …

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Film Boiling Of Nitrogen From A Spherical Heating Surface At Atmospheric Pressure And Standard Gravity, Juan Jorge MariáNyi Jan 1968

Film Boiling Of Nitrogen From A Spherical Heating Surface At Atmospheric Pressure And Standard Gravity, Juan Jorge MariáNyi

Masters Theses

"A steady state film boiling heat transfer study was conducted at atmospheric pressure, with a heated sphere as the heat transfer surface and liquid nitrogen as the boiling medium. Results indicate that the heat transfer rate in film boiling is not the same around the sphere. For the same heat flux, heat transfer at the sides of the sphere takes place at higher temperatures than at the bottom of the sphere. The data were compared with the equation of Frederking and Clark for spheres (1̲8̲), which was derived to predict steady state conditions at standard, fractional and near zero gravity. …

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The Compressibility Of Preconsolidated Till, William H. Koechlein Jan 1968

The Compressibility Of Preconsolidated Till, William H. Koechlein

Masters Theses

"Preconsolidated glacial till was tested "in-situ" with the Geoprobe and in the laboratory on undisturbed soil samples. The two soil testing methods were compared and three tests; consolidation, "thin-cake", and Geoprobe were analyzed to see if a more rapid method for determining the preconsolidation stress of soil could be developed. When comparing Geoprobe results to laboratory results for foundation conditions, it was found the two methods agreed on bearing capacity but differed significantly on settlement. The three tests analyzed for determining the preconsolidation stress indicated they are a function of preconsolidation stress even though there was variation in the test …

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The Computer-Aided Generation Of Flow-Tables For Asynchronous Sequential Circuits, Ronald Lee Altman Jan 1968

The Computer-Aided Generation Of Flow-Tables For Asynchronous Sequential Circuits, Ronald Lee Altman

Masters Theses

"One step in the synthesis of asynchronous sequential circuits is the construction of a flow table. This paper discusses the requirements of a computer program to allow on-line generation of flow tables for asynchronous sequential circuits. Such topics as the form of the data entered into the program, the type of terminal required, the routines necessary for the designer to enter and correct data, and the internal data structure are discussed. An algorithm for the generation of these flow tables is also presented"--Abstract, page ii.

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The Density Of Horizontal Control In Missouri, Norman Lee Brown Jan 1968

The Density Of Horizontal Control In Missouri, Norman Lee Brown

Masters Theses

"In 1965 the Missouri Legislature passed House Bill 201 adopting the Missouri Plane Coordinate System as computed by the United States Coast and Geodetic Survey. The requirements of this law and the density and distribution of usable control within the state is the topic of this thesis"--Abstract, page ii.

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A Study Of A Model-Referenced Adaptive Control System, James William Graham Jan 1968

A Study Of A Model-Referenced Adaptive Control System, James William Graham

Masters Theses

"A model-referenced adaptive controller for a first-order plant with time-varying parameters is developed using Lyapunov's second method. The system is studied with the aid of analogue computer simulation and an oscillatory mode is encountered. A method of reducing the oscillations by addition of a compensating network is proposed. The compensation is obtained through the use of linearization and root locus techniques. The compensated system shows a much improved error response over the original system"--Abstract, page ii.

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A Mechanical Metallurgical Method Of Predicting The Springback Tendencies Of A Bent Metal Strip, Jerrold Myles Alyea Jan 1968

A Mechanical Metallurgical Method Of Predicting The Springback Tendencies Of A Bent Metal Strip, Jerrold Myles Alyea

Masters Theses

"Attempted substitution of new solid materials and composite metal strips for those materials presently being used in many applications now being pursued vigorously in industry. A serious problem was created because the newly proposed materials do not exhibit the same springback after bending as did the previously used materials in a particular bend angle and radius situation. Elementary bend theory and mechanical metallurgical techniques have been incorporated into a method which can be used to accurately predict the .2% offset yield strength of any proposed rolled-temper solid metal strip and some composite strips when they must exhibit the same springback …

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A Method Of Supervised Pattern Recognition By An Adaptive Hypersphere Decision Threshold, Darroll Steven Mccormack Jan 1968

A Method Of Supervised Pattern Recognition By An Adaptive Hypersphere Decision Threshold, Darroll Steven Mccormack

Masters Theses

"In this study the Bayes likelihood detector is combined with an adaptive decision threshold classifier to solve the multicategory pattern recognition problem. It is assumed that the pattern classes can be represented by an n-dimensional vector sample taken from a multivariate gaussian probability distribution. This study presents (1) the derivation of the A̲daptive H̲ypersphere D̲ecision T̲hreshold classifier (AHDT classifier) and shows (2) how the AHDT classifier minimizes the probability of error using the learning patterns. Finally the AHDT classifier is applied to the solution of a physical problem through computer simulation"--Abstract, page ii.

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The Influence Of Silt On The Compressibility Of An Illitic Clay, James Inman Spencer Jan 1968

The Influence Of Silt On The Compressibility Of An Illitic Clay, James Inman Spencer

Masters Theses

"This study was undertaken to investigate the effect of varying amounts of clay (illite) on the compressibility of a silt as it may be found in nature in a normally consolidated deposition. Laboratory procedure was designed to minimize sample disturbance so as to obtain, as nearly as possible, a virgin consolidation curve. By varying the amounts of silt and clay in a given sample, and sedimenting the sample from a soil-water suspension, consolidation test analyses were used for a comparison of the various samples. Results revealed that between sample mixtures of 40 and 60 percent silt there was a relatively …

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Corrosion Rates And Electrokinetics Of Cobalt And Cobalt-Rich Cobalt-Iron Alloys In Sulfuric And Hydrochloric Acids, Cheng Tzong Horng Jan 1968

Corrosion Rates And Electrokinetics Of Cobalt And Cobalt-Rich Cobalt-Iron Alloys In Sulfuric And Hydrochloric Acids, Cheng Tzong Horng

Masters Theses

"Corrosion rates for Co and Co-rich Co-Fe alloys were determined in sulfuric and hydrochloric acids under both deaerated and oxygenated conditions. For the purpose of comparison, corrosion rates of Co cut from metal sheet were also determined in the same environments as those of sintered alloys. Sintered alloys were inferior to solid Co as corrosion resistant materials. It was found that the surface was more corrosion resistant than the interior. Thus after long exposure to the corrosive acid, the samples became porous inside while the surfaces remained substantially intact. Oxygen had a pronounced effect in accelerating the corrosion of Co …

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A Comparison Of Proportional And Nonproportional Damping In Multistory Shear Buildings, Edwin C. Bailey Jan 1968

A Comparison Of Proportional And Nonproportional Damping In Multistory Shear Buildings, Edwin C. Bailey

Masters Theses

"The purpose of this study was to determine whether proportional damping could be used to satisfactorily simulate the more practical nonproportional damping condition in multistory shear buildings. To accomplish this one computer program was written to analyze proportionally damped systems and another to analyze nonproportionally damped systems, each giving as output the frequencies, mode shapes, displacements, shears and moments and the maximum shears and moments. Shear buildings of two, three and four stories were studied in which the damping coefficients were varied from one to ten percent of critical damping. Although the programs could handle various other types, only linearly …

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Permeability And Additive Sorption And Extraction In Lubricating Greases, Chan-Shan Fan Jan 1968

Permeability And Additive Sorption And Extraction In Lubricating Greases, Chan-Shan Fan

Masters Theses

"The effect of the area and type of surface of ten silica thickeners and aluminum oxide on grease permeability, on the sorption of PAN [Phenyl-α-naphthylamine] by the grease, and on subsequent extraction were studied. For grease containing 6% per cent of thickener, permeability coefficients varied from 20.1 x 10⁻¹¹ cm² to 168 x 10⁻¹¹ cm². For each silica type they decreased with increase in surface area of the thickener. The level of the permeability coefficient is generally related to the worked penetration. In sorption measurements using permeating oils of varying PAN concentration, the amount of PAN associated with the thickener …

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Influence Of Nobler Metal Salt Additions Upon The Dissolution Rate Of Aluminum In Hydrofluoric Acid, Barry L. Basden Jan 1968

Influence Of Nobler Metal Salt Additions Upon The Dissolution Rate Of Aluminum In Hydrofluoric Acid, Barry L. Basden

Masters Theses

"The rate of dissolution of aluminum in 2N HF upon the addition of nobler metallic salts was studied. Aluminum corrodes in HF due to the acid's ability to dissolve the protective oxide present on the surface. Rates were measured by the hydrogen evolution method. Salt additions of AgN0₃, CuSO₄, HAuC₄, and PtCl₄ to aluminum dissolving in 2N HF resulted in the electroless deposition of more or less coherent metals (from the salts mentioned) on the aluminum surface. The dissolution rate initially decreased in all of the cases and was attributed to the "blanketing effect" of the deposits. Ensuing increases of …

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