The purpose of this investigation was to determine the corrosion characteristics of Incoloy alloy 825 in 1.0 to 15.0 normal sulfuric and 0.5 to 3.0 normal hydrochloric acids at 25 to 60°C in both nitrogen-saturated and air-saturated acids, using potentiostatic polarization techniques. Anodic polarization curves were obtained by changing the potential of an Incoloy 825 test electrode and measuring the resulting current. In both acids, there is no difference in the polarization characteristics in air-or nitrogen-saturated solutions. In 1.0 to 15.0 normal sulfuric acid at 25 to 60°C, the alloy spontaneously passivates and does not exhibit a significant active region. In 0.5 normal hydrochloric acid at 25°C, Incoloy 825 is spontaneously passive, but is active at higher concentrations. At 25°C, as the hydrochloric acid concentration increases from 1.0 to 3.0 normal,the critical current density increases from 260 to 5900 microamperes per square centimeter. At 40°C, as the acid concentration increases from 0.5 to 2.0 normal, the critical current density increases from 25 to 28,000 microamperes per square centimeter. In 1.0 normal hydrochloric acid at 25°C, the corrosion rate calculated by weight loss measurements for potentiostatically controlled Incoloy 825 agrees closely with the corrosion rate calculated from polarization current densities, and indicates that the elements dissolve in the proportions present in the alloy. Potentiostatically passivated Incoloy 825 in 1.0 normal hydrochloric acid at 25°C does not exhibit a stable passive condition, reverting to the active state in less than 12 hours. / M.S.

Several researchers engaged in family housing have recently become concerned about the vibrational behavior of residential floors. This concern resulted in a need for methods of sensing floor vibrations. Some investigators have sensed floor vibrations with electric resistance strain gauges bonded to the underside of the floor joists. These experiments using strain gages as vibration sensing devices resulted in a need to be able to determine the vibration amplitude (or deflection) from strain vibration data. The objectives of this project were to theoretically and experimentally determine the relationship between midspan flexural strain and midspan deflection of freely vibrating wood beams with various end conditions. Theoretical strain-deflection relationships of freely vibrating wood beams with pinned-end and fixed-end conditions were derived from vibration theory. Free vibration tests on three wood beams with pinned-ends and fixed-ends gave results which were in agreement with theory. The theoretical relationship between the end rigidity and natural frequency of beams with semi-rigid end connections was derived. Vibration tests performed on wood beams with semi-rigid end connections produced frequency-rigidity results which agreed with theory within five percent. The semi-rigid end connections were achieved by using a torsion bar on each end designed so that the beam would have a static behavior midway between pinned-end conditions and fixed-end conditions. However, it was found both theoretically and experimentally that these torsion bars resulted in a dynamic behavior (strain-deflection ratio and frequency) much closer to pinned-end conditions than to fixed-end conditions. It was established that the strain-deflection relationship of freely vibrating wood beams can be predicted from vibration theory if the rigidity of the end connections is known. / Master of Science

M.S.

The specific dynamic effects of carbohydrate, fat and protein were measured in five adult women. Basal metabolic rates were measured while subjects were in the post-absorptive state. Subjects ingested 5.7 Cal./kg of body weight of the nutrients on different days. Measurements were made at regular time intervals after the meal until the amount of expired air approximated that of the basal state. Samples of expired air were analyzed for oxygen and carbon dioxide. Changes in the respiratory quotient and Cal. per square meter of body surface, with relationship to time of ingestion of each pure compound were studied. There was a general trend for subjects with higher basal energy metabolism to have greater increases in the respiratory quotient after the ingestion of carbohydrate, or fat or protein. An increase in respiratory quotient and beat production was observed following the ingestion of each of three nutrients. There was no definite correlation between the changes in respiratory quotient and variations in heat production after ingestion of carbohydrate, fat and protein by women. Individuals varied in their responses to carbohydrate, fat and protein, but similarities among the individuals in their response to each of these foodstuff was apparent. / Master of Science

A nonlinear analysis is developed for eddy-current couplings in feedback control systems. The analysis makes use of the describing function method to predict transient response. Effects of the nonlinearity are discussed and backed with an analog computer study. Conclusions arrived at show the absquare nonlinearity to be advantageous under conditions of zero steady state loading or offset. Under conditions of steady state loading, shifting of the load operating point causes a wide variation in response. This situation is remedied with nonlinear compensation. / Master of Science

M.S.

M. S.

The Wiener theory of the minimum mean square error ·criterion is well furnished by knowing the autocorrelation function of the input to the linear system. This input signal is generally an additive mixture of a piecewise continuous message and a noise. The problem considered in this paper is the determination of the autocorrelation function and also their power density spectrum of the noise component for the random base and height modulated square wave whose leading edges are periodic functions of time. We note that the adopted probability density function for heights of random square wave have Gamma-Distribution Density Function. In addition to this distribution function, we consider the rectangular and Beta-density function on the base of square waves. In fact, the leading edges of most periodic-random base function can be simply described by using the rectangular and Beta-Density function. Another matter under consideration is the visualization of the variations noise power density spectrum immersed in the masked signal (mixtured signal) with respect to the variance σ² and s² of Gamma and Beta-distribution, respectively. / M.S.

Diffusion couples between nickel and S.A. 212 ferritic steel and between nickel and AISI 304 austenitic stainless steel were studied to determine the effect of nickel on the structure of these steels after diffusion anneals at 1300 ℉. Diffusion times varied from 50 to 4000 hours. The migration of nickel resulted in the formation of a martensitic band between nickel and S.A. 212 ferritic steel and an austenitic band between nickel and AISI 304 austenitic stainless steel. The width of the bands increased exponentially with the time of annealing. The band width increased faster in nickel-S.A. 212 couple than in nickel-AISI 304 couple. Hardness values were obtained within the band of both diffusion couples and varied across the band. Generally, the hardness was greatest in the band. In the nickel-AISI 304 diffusion couple, chromium carbides were observed in the nickel plate after diffusion. / M.S.

M.S.