Browsing by Author "Johnson, Chanel"

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    Idea Density Correlates with Prior Knowledge
    (Office of the Vice Chancellor for Research, 2014-04-11) Johnson, Chanel
    It is widely accepted in educational research that student’s prior knowledge influences new learning. It is easier to comprehend text and content on that particular subject because of the students prior knowledge. If the person does not have any knowledge on the subject, how can a person process the information given? The concept of idea density deals with the measurement of texts, and is a subset of conceptual density. The formal definition states “the number of propositions divided by the number of words” (Covington, 2008). The idea density of a text determines the amount of work a reader must do in order to understand it. Readers who are already familiar with a subject can comfortably process text with high idea density than a person who is new to the field. The purpose of this research is to determine whether and to what degree is idea density an indirect measure of the amount of presupposed knowledge. The authors will conduct a series of experiments and collect data. The goal is to analyze the data and determine if conceptual density has any affect on learning. Mentor: Jomo Mutegi, IU School of Education, IUPUI
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    Modeling Nanomaterials in Lithium Ion Battery with Experimental Validation
    (Office of the Vice Chancellor for Research, 2015-04-17) Johnson, Chanel; Hammans, Andrea; Hurtman, James; Clyde, David; Wu, Linmin; Jung, Yeon-Gil; Zhang, Jing
    A lithium-ion battery (Li-ion battery or LIB) is a rechargeable battery type in which lithium ions move from the negative electrode to the positive electrode during discharge and back when charging. Lithium systems are of considerable interest due to their high energy density and low toxicity compared to other rechargeable lithium battery chemistries. Conventional Lithium-ion battery materials typically start as 10-50 micron sized particles. In many of these new chemistries, having the materials in nanoparticle form or as a nanostructured particle or film is critical to achieving the desired performance. The goal of this study is to understand the mechanisms that govern the size-dependence of electrochemical properties and mechanical properties of nanomaterials in Lithium ion batteries using first principles method. We have been developing computational models of LiCoO2 crystals. The specific objectives of the MURI project are to: (1) conduct first principles study of the electrochemical properties and mechanical properties of nanosize LiCoO2; (2) investigate Li ion diffusion phenomena in the nanomaterial; and (3) experimentally validate the computational results.