An alternative model for estimating liquid diffusion coefficients requiring no viscosity data

An equation, based on the free volume of a liquid solvent, was derived via dimensional analysis, to predict binary diffusion coefficients. The equation assumed that interaction between the solute and liquid solvent molecules followed a Lennard-Jones potential. The equation was compared to other diffusivity equations and was found to give good results over the temperature range examined

Surface catalytic degradation study of two linear perfluoropolyalkylethers at 345 C

Thin-liquid-film degradation studies of two commercially available perfluoropolyalkylether fluids (PFAE) were performed at 345 C, in nitrogen and air atmospheres, on iron and 440 C stainless steel surfaces. It was found that one fluid degraded on both iron and 440 C stainless steel surfaces in an air atmosphere, whereas the other fluid did not degrade. Chemical analysis revealed that the test fluid degraded to lower molecular weight products and that the degradation was accompanied by the formation of a brownish deposit on both the iron and 440 C stainless steel surfaces. Surface analysis of the deposit revealed a susbstantial amount of iron oxide (Fe2O3). It was hypothesized that the fluid which degraded did so because of its acetal structure. The other fluid, lacking the acetal structure, did not degrade

An efficient estimator for locally stationary Gaussian long-memory processes

This paper addresses the estimation of locally stationary long-range dependent processes, a methodology that allows the statistical analysis of time series data exhibiting both nonstationarity and strong dependency. A time-varying parametric formulation of these models is introduced and a Whittle likelihood technique is proposed for estimating the parameters involved. Large sample properties of these Whittle estimates such as consistency, normality and efficiency are established in this work. Furthermore, the finite sample behavior of the estimators is investigated through Monte Carlo experiments. As a result from these simulations, we show that the estimates behave well even for relatively small sample sizes.Comment: Published in at http://dx.doi.org/10.1214/10-AOS812 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Some results on Gaussian Besov-Lipschitz spaces and Gaussian Triebel-Lizorkin spaces

In this paper we define Besov-Lipschitz and Triebel-Lizorkin spaces in the context of Gaussian harmonic analysis, the harmonic analysis of Hermite polynomial expansions. We study inclusion relations among them, some interpolation results and continuity results of some important operators (the Ornstein-Uhlenbeck and the Poisson-Hermite semigroups and the Bessel potentials) on them. We also prove that the Gaussian Sobolev spaces $L^p_\alpha(\gamma_d)$ are contained in them. The proofs are general enough to allow extensions of these results to the case of Laguerre or Jacobi expansions and even further in the general framework of diffusions semigroups

Environmental Effects of Watershed Modifications

Watershed management is more effective when there is a relief from the population to exploit the land. Undoubtedly, such policies must be premised on a full appreciation of the interdependence and the extent of interaction of the various components of watershed ecosystems This paper defines the basic concepts and assumptions in the discussion of watershed management with the objective of providing sound physical bases for land use policies for rural and forest watershed. Related issues such as soil erosion, water quality and other hydrometereological concerns are hoped to be given future research considerations.natural resources and environment, environmental issues, watershed, environmental management

Soil and Water Conservation Planning: Policy Issues and Recommendations

This article is prepared for the Upland Policy Conference on March 14, 1988. It discusses the degree of soil erosion in various watersheds based on classified descriptive parameters. It also proposes land use planning and allocation scheme.land management, watershed, soil erosion, soil conservation

A transference result of the LpL^p continuity of the Jacobi Riesz transform to the Gaussian and Laguerre Riesz transforms

In this paper using the well known asymptotic relations between Jacobi polynomials and Hermite and Laguerre polynomials. We develop a transference method to obtain the $L^p$-continuity of the Gaussian-Riesz transform and the $L^p$-continuity of the Laguerre-Riesz transform from the $L^p$-continuity of the Jacobi-Riesz transform, in dimension one

Soil and Water Conservation Planning: Policy Issues and Recommendations

This article is prepared for the Upland Policy Conference on March 14, 1988. It discusses the degree of soil erosion in various watersheds based on classified descriptive parameters. It also proposes land use planning and allocation scheme.land management, watershed, soil erosion, soil conservation