Comments Regarding "Study of Molecular Interactions in Binary Mixtures of Formamide with 2-Methoxyethanol and 2-Ethoxyethanol at Varying Temperatures"

Comments Regarding "Study of Molecular Interactions in Binary Mixtures of Formamide with 2-Methoxyethanol and 2-Ethoxyethanol at Varying Temperatures"

Date: June 3, 2013
Creator: Acree, William E. (William Eugene)
Description: This article provides comments on "Study of Molecular Interactions in Binary Mixtures of Formamide with 2-Methoxyethanol and 2-Ethoxyethanol at Varying Temperatures," published in 'Physics and Chemistry of Liquids,' 2013.
Contributing Partner: UNT College of Arts and Sciences
On the density of minimal free subflows of general symbolic flows.

On the density of minimal free subflows of general symbolic flows.

Date: August 2009
Creator: Seward, Brandon Michael
Description: This paper studies symbolic dynamical systems {0, 1}G, where G is a countably infinite group, {0, 1}G has the product topology, and G acts on {0, 1}G by shifts. It is proven that for every countably infinite group G the union of the minimal free subflows of {0, 1}G is dense. In fact, a stronger result is obtained which states that if G is a countably infinite group and U is an open subset of {0, 1}G, then there is a collection of size continuum consisting of pairwise disjoint minimal free subflows intersecting U.
Contributing Partner: UNT Libraries
Comments Regarding "Density, Speed of Sound, Refractive Index and Derivatives Properties of the Binary Mixture N-Hexane + N-Heptane (or N-Octane or N-Nonane), T = 288.15 - 313.15 K"

Comments Regarding "Density, Speed of Sound, Refractive Index and Derivatives Properties of the Binary Mixture N-Hexane + N-Heptane (or N-Octane or N-Nonane), T = 288.15 - 313.15 K"

Date: April 9, 2013
Creator: Acree, William E. (William Eugene) & Stephens, Timothy W.
Description: This article offers comment on "Density, speed of sound, refractive index and derivatives properties of the binary mixture N-Hexane + N-Heptane (or N-Octane or N-Nonane), T=288.15 - 313.15 K."
Contributing Partner: UNT College of Arts and Sciences
A Vygotskian Analysis of Preservice Teachers’ Conceptions of Dissolving and Density

A Vygotskian Analysis of Preservice Teachers’ Conceptions of Dissolving and Density

Date: May 2014
Creator: Shaker elJishi, Ziad
Description: The purpose of this study was to examine the content knowledge of 64 elementary preservice teachers for the concepts of dissolving and density. Vygotsky’s (1987) theory of concept development was used as a framework to categorize concepts and misconceptions resulting from evidences of preservice teacher knowledge including pre/post concept maps, writing artifacts, pre/post face-to-face interviews, examination results, and drawings. Statistical significances were found for pre- and post-concept map scores for dissolving (t = -5.773, p < 0.001) and density (t = -2.948, p = 0.005). As measured using Cohen’s d values, increases in mean scores showed a medium-large effect size for (dissolving) and a small effect size for density. The triangulated results using all data types revealed that preservice teachers held several robust misconceptions about dissolving including the explanation that dissolving is a breakdown of substances, a formation of mixtures, and/or involves chemical change. Most preservice teachers relied on concrete concepts (such as rate or solubility) to explain dissolving. With regard to density, preservice teachers held two robust misconceptions including confusing density with buoyancy to explain the phenomena of floating and sinking, and confusing density with heaviness, mass, and weight. Most preservice teachers gained one concept for density, the density ...
Contributing Partner: UNT Libraries