University of Arkansas

About: University of Arkansas is a education organization based out in Fayetteville, Arkansas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 17225 authors who have published 33329 publications receiving 941102 citations. The organization is also known as: Arkansas & UA.

Ultrathin Films of Ferroelectric Solid Solutions under a Residual Depolarizing Field

Abstract: A first-principles-derived approach is developed to study the effects of depolarizing electric fields on the properties of Pb(Zr,Ti)O3 ultrathin films for different mechanical boundary conditions. A rich variety of ferroelectric phases and polarization patterns is found, depending on the interplay between strain and the amount of screening of surface charges. Examples include triclinic phases, monoclinic states with in-plane and/or out-of-plane components of the polarization, homogeneous and inhomogeneous tetragonal states, as well as peculiar laminar nanodomains.

Structures of Gramicidins A, B, and C Incorporated Into Sodium Dodecyl Sulfate Micelles.

Abstract: Gramicidins A, B, and C are the three most abundant, naturally occurring analogues of this family of channel-forming antibiotic. GB and GC differ from the parent pentadecapeptide, GA, by single residue mutations, W11F and W11Y, respectively. Although these mutations occur in the cation binding region of the channel, they do not affect monovalent cation specificity, but are known to alter cation-binding affinities, thermodynamic parameters of cation binding, conductance and the activation energy for ion transport. The structures of all three analogues incorporated into deuterated sodium dodecyl sulfate micelles have been obtained using solution state 2D-NMR spectroscopy and molecular modeling. For the first time, a rigorous comparison of the 3D structures of these analogues reveals that the amino acid substitutions do not have a significant effect on backbone conformation, thus eliminating channel differences as the cause of variations in transport properties. Variable positions of methyl groups in valine and leucine residues have been linked to molecular motions and are not likely to affect ion flow through the channel. Thus, it is concluded that changes in the magnitude and orientation of the dipole moment at residue 11 are responsible for altering monovalent cation transport.

In Situ Observation of the Nucleation and Growth of CdSe Nanocrystals

Abstract: An in situ method is introduced for the study of nucleation and growth of crystals using the size-dependent properties of a given system in the transition size regime from molecular species to bulk sized crystals. The real-time measurements for the first system studied, a CdSe one, were carried out by recording the absorption spectra during the reaction with a millisecond resolution.

Enterprise system implementation and employee: understanding the role of advice networks

Abstract: The implementation of enterprise systems, such as enterprise resource planning (ERP) systems, alters business processes and associated workflows, and introduces new software applications that employees must use. Employees frequently find such technology-enabled organizational change to be a major challenge. Although many challenges related to such changes have been discussed in prior work, little research has focused on post-implementation job outcomes of employees affected by such change. We draw from social network theory-- specifically, advice networks--to understand a key post-implementation job outcome (i.e., job performance). We conducted a study among 87 employees, with data gathered before and after the implementation of an ERP system module in a business unit of a large organization. We found support for our hypotheses that workflow advice and software advice are associated with job performance. Further, as predicted, we found that the interactions of workflow and software get-advice, workflow and software give-advice, and software get- and give-advice were associated with job performance. This nuanced treatment of advice networks advances our understanding of post-implementation success of enterprise systems.