Kent State University

About: Kent State University is a education organization based out in Kent, Ohio, United States. It is known for research contribution in the topics: Liquid crystal & Population. The organization has 10897 authors who have published 24607 publications receiving 720309 citations. The organization is also known as: Kent State & KSU.

Oligoelectrolyte Model for Cation Binding by Humic Substances

Abstract: An oligoelectrolyte model of humic substances is developed to explain ionic strength effects on copper and hydrogen ion titrations. After discussing the relevance of various polyelectrolyte models to humic substances, we choose a model in which the molecules are represented as impenetrable spheres. The electrostatic effect is calculated using numerical solutions of the appropriate nonlinear Poisson-Boltzmann equation. Incorporation of available data on molecular weight distribution, size, and functional group content of humic substances reduces the number of arbitrary fitting parameters

Multiple approaches to estimating air‐water gas exchange in small lakes

Abstract: The rate of gas exchange between air and water is an essential quantity in a number of contexts, from mass balances to the calculation of whole-system metabolism. The exchange of a gas between water and the atmosphere is controlled by differential partial pressures of gases in air and in water (both straightforward to measure) and by the amount of turbulent energy exchange between the air-water interface, the measurement of which is neither simple nor direct. This physical exchange is often expressed as a piston velocity (k). We compared four methods for estimating k in a series of small (0.3 to 45 ha), low-wind (mean wind < 3 m s–1) lakes: 1) floating chambers using ambient CH4; 2) whole-lake SF6 additions; 3) three wind-based models from the literature; and 4) C mass balances constrained by whole-lake 13C additions. All of the methods, with the exception of one windbased model, converged on values for k600 of between 0.35 and 0.74 m d–1 with no biases among methods. The floating chambers, if designed properly, are a cost-effective way of obtaining site-specific values of k for low wind lakes over fairly short time frames (hours).

The economic exposure of u.s. multinational firms

Abstract: In this paper we find that the exchange rate exposure of individual firms increases with the return horizon. Also, the cross-sectional differences in the magnitude of exposure of individual firms are significantly related to firm size but not to the relative portion of foreign sales to total sales. The empirical evidence is consistent with the hypothesis that hedging activities exhibit economies of scale, and, consequently, the magnitude of economic exposure is less for larger firms than for smaller firms.

Morphological Analysis of the Mammalian Postcranium: A Developmental Perspective

Abstract: The past two decades have greatly improved our knowledge of vertebrate skeletal morphogenesis. It is now clear that bony morphology lacks individual descriptive specification and instead results from an interplay between positional information assigned during early limb bud deployment and its “execution” by highly conserved cellular response programs of derived connective tissue cells (e.g., chondroblasts and osteoblasts). Selection must therefore act on positional information and its apportionment, rather than on more individuated aspects of presumptive adult morphology. We suggest a trait classification system that can help integrate these findings in both functional and phylogenetic examinations of fossil mammals and provide examples from the human fossil record.