Low gravity phase separator

An apparatus is described for phase separating a gas-liquid mixture as might exist in a subcritical cryogenic helium vessel for cooling a superconducting magnet at low gravity such as in planetary orbit, permitting conservation of the liquid and extended service life of the superconducting magnet

Joint statistics of acceleration and vorticity in fully developed turbulence

We report results from a high resolution numerical study of fluid particles transported by a fully developed turbulent flow. Single particle trajectories were followed for a time range spanning more than three decades, from less than a tenth of the Kolmogorov time-scale up to one large-eddy turnover time. We present results concerning acceleration statistics and the statistics of trapping by vortex filaments conditioned to the local values of vorticity and enstrophy. We distinguish two different behaviors between the joint statistics of vorticity and centripetal acceleration or vorticity and longitudinal acceleration.Comment: 8 pages, 6 figure

Intergenerational Effects of the Distribution of Income and Wealth: The Utah Experience, 1850-1900

The relationship between the wealth or income of parents and children is an important economic issue in both positive and normative senses. In this paper, we estimate elasticities of sons' income or wealth with respect to the wealth of their fathers for a sample of households in nineteenth century Utah. We find the elasticity relating the wealth of fathers to sons to range from .10 to .34 depending on the variables held constant such as occupation, age and residence. Elasticities based on observation of the wealth of fathers and sons in the same year were higher than those based on a lagged value of the fathers' wealth. The death of the father prior to observation of the sons' wealth increased the elasticity about three fold. The elasticity between the income of sons and wealth of fathers was low (.09 to .21) but significant even though the sons' incomes were observed fifteen years after the wealth of fathers. In general, the data suggest a persistent relationship between the economic status of parents and their children with substantial regression toward the mean so that an economic elite was unlikely to be based upon intergenerational transmission of economic success.

Analytical prediction of the interior noise for cylindrical models of aircraft fuselages for prescribed exterior noise fields. Phase 2: Models for sidewall trim, stiffened structures and cabin acoustics with floor partition

An airplane interior noise prediction model is developed to determine the important parameters associated with sound transmission into the interiors of airplanes, and to identify apropriate noise control methods. Models for stiffened structures, and cabin acoustics with floor partition are developed. Validation studies are undertaken using three test articles: a ring stringer stiffened cylinder, an unstiffened cylinder with floor partition, and ring stringer stiffened cylinder with floor partition and sidewall trim. The noise reductions of the three test articles are computed using the heoretical models and compared to measured values. A statistical analysis of the comparison data indicates that there is no bias in the predictions although a substantial random error exists so that a discrepancy of more than five or six dB can be expected for about one out of three predictions

Wealth Mobility: The Missing Element

We consider the problems that may arise when cross sectional data alone are used for inferences about individual welfare, the existence of elites, the possibilities of class boundaries, the openness of a society, etc. We also consider problems with alternative measures of socio-economic position. We then use a sample of 2400 households observed over one or two decade intervals together with data on the population of households at each observation point to examine mobility within the distribution of wealth for an almost closed economy, Utah, 1850-1870. We use information on households to examine those characteristics that contribute to mobility. We find considerable mobility, much apparently stochastic, within quite highly skewed distributions of wealth that also exhibit increasing inequality through time.

Unobservable Family and Individual Contributions to the Distributions ofIncome and Wealth

This paper uses a data set composed of combinations of full brothers, half brothers as well as fathers and sons to measure the effect of common family background on households'income and wealth. While the data is drawn from a nineteenth century population, the intra-class correlation (after the effects of age, occupation, nativity, residence and duration in the economy have been removed) for income ranges from .13 to .18 which is similar to that found in modern samples. Intra-class correlations for wealth are significantly higher (.18 to .35) than those for income. The addition of fathers' observed characteristics to the sweeping regressions reduces the unobserved common background effect shared by brothers by about twenty percent.The intra-class correlations of half brothers were lower than those observed for full brothers though the small differences between the two groups suggest that fathers played a dominant role in the transmission of the common family effect. Unobserved background was decomposed into individual and family effects by a variance components procedure. The individual effect was dominant for income while the family effect was dominant for wealth.