Hou Y.,Duke University |
Cheng Y.,Duke University |
Hobson T.,Riverside High School |
Liu J.,Duke University
Nano Letters | Year: 2010
For efficient use of metal oxides, such as MnO2 and RuO 2, in pseudocapacitors and other electrochemical applications, the poor conductivity of the metal oxide is a major problem. To tackle the problem, we have designed a ternary nanocomposite film composed of metal oxide (MnO 2), carbon nanotube (CNT), and conducting polymer (CP). Each component in the MnO2/CNT/CP film provides unique and critical function to achieve optimized electrochemical properties. The electrochemical performance of the film is evaluated by cyclic voltammetry, and constant-current charge/discharge cycling techniques. Specific capacitance (SC) of the ternary composite electrode can reach 427 F/g. Even at high mass loading and high concentration of MnO2 (60%), the film still showed SC value as high as 200 F/g. The electrode also exhibited excellent charge/discharge rate and good cycling stability, retaining over 99% of its initial charge after 1000 cycles. The results demonstrated that MnO2 is effectively utilized with assistance of other components (fFWNTs and poly(3,4-ethylenedioxythiophene) -poly(styrenesulfonate) in the electrode. Such ternary composite is very promising for the next generation high performance electrochemical supercapacitors. © 2010 American Chemical Society.
Heil C.S.S.,Duke University |
Manzano-Winkler B.,Duke University |
Hunter M.J.,Riverside High School |
Noor J.K.F.,Duke University |
Noor M.A.F.,Duke University
American Biology Teacher | Year: 2013
We present a laboratory exercise that leverages student interest in genetics to observe and understand evolution by natural selection. Students begin with white-eyed fruit fly populations, to which they introduce a single advantageous variant (one male with red eyes). The superior health and vision associated with having the red-eye-color allele confers a fitness advantage, and the students can watch the spread of the allele within the population. The increasing numbers of red-eyed flies they observe over generations demonstrate evolution by natural selection. The students concurrently learn genetic principles, including basic inheritance and X-linkage. © 2013 by National Association of Biology Teachers.
Dalby D.K.,Riverside High School |
Maynard J.H.,University of Wisconsin - Madison |
Moore J.W.,University of Wisconsin - Madison
Journal of Chemical Education | Year: 2011
A method for demonstrating and expanding the Ira Remsen copper penny and nitric acid experience has been developed. It involves additional chemistry, showing five transformations of copper from one form to another. © 2011 The American Chemical Society and Division of Chemical Education, Inc.
Carlo D.D.,University of Northern Iowa |
Hinkhouse H.,Riverside High School |
Isbell L.,Gilbert High School
Journal of Science Education and Technology | Year: 2010
This paper outlines the connection between qualitative research methods in education and teacher reflective practices as they relate to Valli's (Reflective teacher education: cases and critiques. State University of New York Press, Albany, 1992; Peabody J Educ 72(1): 67-88, 1997) model of reflection. Using the authors' own experiences in performing and guiding educational research, and existing research in the field of teacher education pertaining to reflective practitioners, explicit connections are made between the two paradigms. These connections illustrate the importance of integrating authentic research experiences into the teacher education curriculum outside the context of methods courses, much like models established in the sciences. © Springer Science+Business Media, LLC 2009.