Physics Commons^™

Evaluation Of Pulmonary And Systemic Toxicity Following Lung Exposure To Graphite Nanoplates: A Member Of The Graphene-Based Nanomaterial Family, Jenny R. Roberts, Robert R. Mercer, Aleksandr B. Stefaniak, Mohindar S. Seehra, Usha K. Geddam, Ishrat S. Chaudhuri, Angelos Kyrlidis, Vamsi K. Kodali, Tina Sager, Allison Kenyon, Suzan A. Bilgesu, Tracy Eye, James F. Scabilloni, Stephen S. Leonard, Natalie R. Fix, Diane Schwegler-Berry, Breanne Y. Farris, Michael G. Wolfarth, Dale W. Porter, Vincent Castranova, Aaron Erdely

Faculty & Staff Scholarship

Background: Graphene, a monolayer of carbon, is an engineered nanomaterial (ENM) with physical and chemical properties that may offer application advantages over other carbonaceous ENMs, such as carbon nanotubes (CNT). The goal of this study was to comparatively assess pulmonary and systemic toxicity of graphite nanoplates, a member of the graphene-based nanomaterial family, with respect to nanoplate size.

Methods: Three sizes of graphite nanoplates [20 μm lateral (Gr20), 5 μm lateral (Gr5), and <2 >μm lateral (Gr1)] ranging from 8–25 nm in thickness were characterized for difference in surface area, structure,, zeta potential, and agglomeration in dispersion medium, the vehicle for …

Examining The Effects Of Testwiseness In Conceptual Physics Evaluations, Seth Devore, John Stewart, Gay Stewart

Faculty & Staff Scholarship

Testwiseness is defined as the set of cognitive strategies used by a student that is intended to improve his or her score on a test regardless of the test’s subject matter. Questions with elements that may be affected by testwiseness are common in physics assessments, even in those which have been extensively validated and widely used as evaluation tools in physics education research. The potential effect of several elements of testwiseness were analyzed for questions in the Force Concept Inventory (FCI) and Conceptual Survey on Electricity and Magnetism that contain distractors that are predicted to be influenced by testwiseness. This …

Identification Of Photocurrents In Topological Insulators, Derek A. Bas, Rodrigo A. Muniz, Sercan Babakiray, David Lederman, J. E. Sipe, Alan D. Bristow

Faculty & Staff Scholarship

Optical injection and detection of charge currents is an alternative to conventional transport and photoemission measurements, avoiding the necessity of invasive contact that may disturb the system being examined. This is a particular concern for analyzing the surface states of topological insulators. In this work one- and two-color sources of photocurrents are isolated and examined in epitaxial thin films of Bi2Se3. We demonstrate that optical excitation and terahertz detection simultaneously captures one- and two-color photocurrent contributions, which has not been required for other material systems. A method is devised to extract the two components, and in doing so each can …