Thermodynamic phase-field model for microstructure with multiple components and phases: the possibility of metastable phases

A diffuse-interface model for microstructure with an arbitrary number of components and phases was developed from basic thermodynamic and kinetic principles and formalized within a variational framework. The model includes a composition gradient energy to capture solute trapping, and is therefore suited for studying phenomena where the width of the interface plays an important role. Derivation of the inhomogeneous free energy functional from a Taylor expansion of homogeneous free energy reveals how the interfacial properties of each component and phase may be specified under a mass constraint. A diffusion potential for components was defined away from the dilute solution limit, and a multi-obstacle barrier function was used to constrain phase fractions. The model was used to simulate solidification via nucleation, premelting at phase boundaries and triple junctions, the intrinsic instability of small particles, and solutal melting resulting from differing diffusivities in solid and liquid. The shape of metastable free energy surfaces is found to play an important role in microstructure evolution and may explain why some systems premelt at phase boundaries and phase triple junctions while others do not.Comment: 14 pages, 8 figure

Watermelon bacterial fruit blotch (2002)

"New 1/02/5M.""Integrated pest management.

Influence of the Amazon River outflow on the ecology of the western tropical Atlantic I. Hydrography and nutrient chemistry

The influence of the Amazon River discharge on the nutrient chemistry and biological productivity in the western tropical Atlantic and the eastern Caribbean was investigated during two oceanogr aphic cruises in the fall of 1964 and the spring of 1965, respectively. The river outflow is entrained in the Guiana Current and carried to the north and east, affecting an area that is at times a million square miles, as indicated by surface salinity...

The Continuing Voids in Texas Groundwater Law: Are Concepts and Terminology to Blame.

Abstract Forthcoming

Development and Evaluation of the Family Asset Builder: A New Child Protective Services Intervention to Address Chronic Neglect

Over the past 20 years, neglect has been the most pervasive form of child maltreatment in the United States, affecting more than half a million children annually. Further, neglect is more likely than other forms of maltreatment to occur repeatedly within child welfare-involved families. Children experiencing neglect, especially early in childhood and with regularity, face long-term deleterious effects on their physical, cognitive, social, and emotional development. Despite the ubiquity of neglect throughout child welfare and the potentially devastating consequences, interventions designed to target families chronically reported to Child Protective Services (CPS) for neglect are scant. The Family Asset Builder intervention asserts that a strengths-based, supportive model of service delivery is essential to break the cycle of neglect early along the continuum of CPS involvement for families. Informed by current theory and practice, the solution-focused intervention offers intensive case management services (including more frequent contact and extended service delivery duration) to families with a history of neglect. Early in 2011, the Family Asset Builder intervention was piloted in two Minnesota counties; this study evaluates the development of the model, lessons learned from implementation, and early findings from the intervention, all of which set the stage for replication of the model and expansion of practice knowledge around chronic neglect