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Empirical Extension (empirical + extension)
Selected AbstractsA theoretical and empirical extension to the transformational leadership constructJOURNAL OF ORGANIZATIONAL BEHAVIOR, Issue 7 2001Vicki L. Goodwin The contingent rewards subscale of the Multifactor Leadership Questionnaire (MLQ) was examined in an attempt to theoretically explain recent empirical results linking contingent rewards to transformational rather than transactional leadership. In Study 1, we supported the proposal that the items in the contingent rewards subscale represented two separate factors, an explicit and an implicit psychological contract. In addition, the implicit factor loaded with other transformational subscales and the explicit factor loaded with other transactional subscales. We confirmed these results in Study 2, and supported other hypotheses from transformational leadership theory using the contingent rewards revision. Implications for the transformational leadership construct are discussed. Copyright © 2001 John Wiley & Sons, Ltd. [source] Characterization of solvatochromic probes: simulation of merocyanine 540 absorption spectra in binary solvent mixtures and pure solvent systemsJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 3 2004S. Y. Bae Abstract An empirical extension of the continuum model was used to reproduce the absorption spectrum of the optical probe merocyanine 540 in numerous solvents based on 27 probe-specific parameters in conjunction with the dielectric constant and refractive index of the solvent. The calibrated absorption spectrum of this dye allowed the accurate determination of the dielectric constant and refractive index of the bulk solvent. This study incorporates several binary solvent mixtures in addition to several pure solvents of differing functionality, including protic and aprotic solvents. A single, generally applicable, set of probe-specific parameters is presented. The accuracy of the determined solvent properties using this general set of probe parameters suggests that the influence of specific solvent,solute interactions on the absorption spectrum of this dye must be constant if not insignificant in the range of solvents studied, with the notable exception of water. Copyright © 2004 John Wiley & Sons, Ltd. [source] Effect of marangoni stresses on the deformation and coalescence in compatibilized immiscible polymer blendsPOLYMER ENGINEERING & SCIENCE, Issue 10 2002Peter Van Puyvelde The effect of physical compatibilization on the deformation and coalescence of droplets in immiscible polymer blends is discussed. Evidence is provided for the existence of concentration gradients in block copolymers along the interface during deformation. This causes complex changes in droplet shapes during deformation and relaxation. These concentration gradients also result in Marangoni stresses, which stabilize the droplets against deformation and breakup. Coalescence experiments have been performed, varying both the compatibilizer concentration and the shear rate. Existing coalescence models have been evaluated. An empirical extension of Chesters' partially mobile interface model is presented, that treats the effects of Marangoni stresses on the coalescence process as a higher effective viscosity ratio. [source] Continuum molecular electrostatics, salt effects, and counterion binding,A review of the Poisson,Boltzmann theory and its modificationsBIOPOLYMERS, Issue 2 2008Grochowski Abstract This work is a review of the Poisson,Boltzmann (PB) continuum electrostatics theory and its modifications, with a focus on salt effects and counterion binding. The PB model is one of the mesoscopic theories that describes the electrostatic potential and equilibrium distribution of mobile ions around molecules in solution. It serves as a tool to characterize electrostatic properties of molecules, counterion association, electrostatic contributions to solvation, and molecular binding free energies. We focus on general formulations which can be applied to large molecules of arbitrary shape in all-atomic representation, including highly charged biomolecules such as nucleic acids. These molecules present a challenge for theoretical description, because the conventional PB model may become insufficient in those cases. We discuss the conventional PB equation, the corresponding functionals of the electrostatic free energy, including a connection to DFT, simple empirical extensions to this model accounting for finite size of ions, the modified PB theory including ionic correlations and fluctuations, the cell model, and supplementary methods allowing to incorporate site-bound ions in the PB calculations. © 2007 Wiley Periodicals, Inc. Biopolymers 89: 93,113, 2008. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] | ||||||||||