Search

Critical thinking (CT) skills are essential to academic and professional success. Instruments to assess CT often rely on multiple‐choice formats with inherent problems. This research presents two instruments for assessing CT, an essay and open‐ended group‐discussion format, which were implemented in an undergraduate business course at a large public university. The topics were intentionally chosen to be digitally‐related (internet access and social media) since they raise complex issues, are applicable in many disciplines, and students are avid users, thereby making these instruments relevant, multidisciplinary, engaging, and multifaceted. These instruments may be adapted to enable educators to effectively assess undergraduate students' ability to think critically. Qualitative analysis of the verbatim data with NVivo helps demonstrate the instruments' efficacy in assessing CT, with (1) high‐quality responses receiving high grades, and (2) overarching themes identified by content analysis, that coalesce into the three dimensions of social justice theory (distributive, procedural, and interactional), thus illustrating students' consideration of complex fairness norms and societal needs. Excerpts of student responses are provided as illustrations of the indicators/evidence of critical thinking. Educators can use these instruments to first assess students' CT skills, and then devise targeted interventions to improve the quality of students' thought processes. [ABSTRACT FROM AUTHOR]

The development of organic semiconductors for use in thermoelectrics requires the optimization of both their thermopower and electrical conductivity. Here two fundamentally different doping mechanisms are used to investigate the thermoelectric properties of known high hole mobility polymers: poly 3-hexylthiophene (P3HT), poly(2,5 -bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT-C14), and poly(2,5-bis(thiphen-2-yl)-(3,7-diheptadecantyltetrathienoacene)) (P2TDC17-FT4). The small molecule tetrafluorotetracyanoquinodimethane (F4TCNQ) is known to effectively dope these polymers, and the thermoelectric properties are studied as a function of the ratio of dopant to polymer repeat unit. Higher electrical conductivity and values of the thermoelectric power factor are achieved by doping with vapor-deposited fluoroalkyl trichlorosilanes. The combination of these data reveals a striking relationship between thermopower and conductivity in thiophene-based polymers over a large range of electrical conductivity that is independent of the means of electrical doping. This relationship is not predicted by commonly used transport models for semiconducting polymers and is demonstrated to hold for other semiconducting polymers as well. [ABSTRACT FROM AUTHOR]

An alkylated semiconducting polymer comprising alternating bithiophene-[all]- S, S-dioxide and aromatic monothiophene units in the polymer backbone was synthesized with the intent of modifying the energy gap and lowest unoccupied molecular orbital for use as a stable n-type semiconductor. Films spun from this semiconducting polymer were characterized utilizing X-ray scattering, near edge X-ray absorption fine structure spectroscopy, ultraviolet photoelectron spectroscopy, and thin-film field effect transistors to determine how oxidation of the thiophene ring systems impacts the structural and electronic properties of the polymer. The thiophene- S,S-dioxide polymers have lower optical and electrical band gaps than corresponding thiophene polymers. X-ray scattering results indicate that the polymers are well ordered with the π-π stacking distances increased by 0.4 Å relative to analogous thiophene polymers. The electrical stability of these polymers is poor in transistors with a drop in the field effect mobility by approximately one order of magnitude upon addition of just 5% of the thiophene- S, S-dioxide unit in a copolymer with thiophene. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013 [ABSTRACT FROM AUTHOR]

The synthesis and characterization of a new family of soluble oligothiophene- S, S-dioxides and their use as building blocks to form polythiophene- S, S-dioxides via microwave-assisted Stille coupling polymerization are described. Incorporation of the sulfone group into the polythiophene backbone leads to narrowing of the polymer bandgap, and while the energies of both Frontier orbitals in polythiophene- S, S-dioxide are lower with respect to polythiophenes, this tendency is considerably stronger for the lowest unoccupied molecular orbital than for the highest occupied molecular orbital, resulting in greater electron-accepting ability. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 [ABSTRACT FROM AUTHOR]