Browsing by Subject "alignment"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Alignment of Faculty Expectations and Course Preparation between First-Year Mathematics and Physics Courses and a Statics and Dynamics Course.(2012-07-16) Shryock, KristiAlignment of the expectations of engineering faculty and the preparation engineering students receive in first-year mathematics and physics mechanics courses provided the motivation for the work contained in this study. While a number of different aspects of student preparation including intangibles, such as motivation, time management skills, and study skills, affect their performance in the classroom, the goal of this study was to assess the alignment of the mathematics and physics mechanics knowledge and skills addressed in first-year courses with those needed for a sophomore-level statics and dynamics course. Objectives of this study included: (1) development of a set of metrics for measuring alignment appropriate for an engineering program by adapting and refining common notions of alignment used in K-12 studies; (2) study of the degree of alignment between the first-year mathematics and physics mechanics courses and the follow-on sophomore-level statics and dynamics course; (3) identification of first-year mathematics and physics mechanics skills needed for a sophomore-level statics and dynamics course through the development of mathematics and physics instruments based on the inputs from faculty teaching the statics and dynamics courses; (4) analysis of tasks given to the students (in the form of homework and exam problems) and the identification of the mathematics and physics skills required; (5) comparison of the required skills to the skills reported by faculty members to be necessary for a statics and dynamics course; and (6) the comparison of student preparation in the form of grades and credits received in prerequisite courses to performance in statics and dynamics. Differences were identified between the content/skills developed in first-year mathematics and physics mechanics courses and content/skills expected by engineering faculty members in the sophomore year. Furthermore, skills stated by engineering faculty members as being required were not necessarily utilized in homework and exam problems in a sophomore engineering mechanics course. Finally, success in first-year physics mechanics courses provided a better indicator of success in a sophomore-level statics and dynamics course than that of first-year mathematics. Processes used in the study could be applied to any course where proper alignment of material is desired.Item Electric field manipulation of polymer nanocomposites: processing and investigation of their physical characteristics(2009-05-15) Banda, SumanthResearch in nanoparticle-reinforced composites is predicated by the promise for exceptional properties. However, to date the performance of nanocomposites has not reached its potential due to processing challenges such as inadequate dispersion and patterning of nanoparticles, and poor bonding and weak interfaces. The main objective of this dissertation is to improve the physical properties of polymer nanocomposites at low nanoparticle loading. The first step towards improving the physical properties is to achieve a good homogenous dispersion of carbon nanofibers (CNFs) and single wall carbon nanotubes (SWNTs) in the polymer matrix; the second step is to manipulate the well-dispersed CNFs and SWNTs in polymers by using an AC electric field. Different techniques are explored to achieve homogenous dispersion of CNFs and SWNTs in three polymer matrices (epoxy, polyimide and acrylate) without detrimentally affecting the nanoparticle morphology. The three main factors that influence CNF and SWNT dispersion are: use of solvent, sonication time, and type of mixing. Once a dispersion procedure is optimized for each polymer system, the study moves to the next step. Low concentrations of well dispersed CNFs and SWNTs are successfully manipulated by means of an AC electric field in acrylate and epoxy polymer solutions. To monitor the change in microstructure, alignment is observed under an optical microscope, which identifies a two-step process: rotation of CNFs and SWNTs in the direction of electric field and chaining of CNFs and SWNTs. In the final step, the aligned microstructure is preserved by curing the polymer medium, either thermally (epoxy) or chemically (acrylate). The conductivity and dielectric constant in the parallel and perpendicular direction increased with increase in alignment frequency. The values in the parallel direction are greater than the values in the perpendicular direction and anisotropy in conductivity increased with increase in AC electric field frequency. There is an 11 orders magnitude increase in electrical conductivity of 0.1 wt% CNF-epoxy nanocomposite that is aligned at 100 V/mm and 1 kHz frequency for 90 minutes. Electric field magnitude, frequency and time are tuned to improve and achieve desired physical properties at very low nanoparticle loadings.