Dynamics and Structure-Property Relationships in Organic Single Crystal Electrical Double Layer Transistors

University of Minnesota Ph.D. dissertation.December 2017. Major: Material Science and Engineering. Advisor: C. Frisbie. 1 computer file (PDF); viii, 152 pages.The goal of this dissertation is to gain a deeper understanding of the factors governing electrical double layer transistor (EDLT) performance. Specifically, the effects of ion structure on EDLT performance are examined in detail towards the end of this work (Chapters 7, 8, and 9). A deep understanding of structure property relationships is fundamental to both being able to design novel high-performance ionic liquids for EDLT applications as well as being able to choose an ideal ionic liquid for a targeted application. Ion structure is a crucial factor determining a wide variety of ionic liquid and EDLT properties with simple structural modifications leading to changes in many ionic liquid and device properties simultaneously. Chapters 1-4 provide background knowledge helpful for understanding the research presented in Chapters 5-8. Chapter 5 explores dynamics of electric double layer formation in ionic liquid-based devices and provides insight about the relevant time scales involved. Chapter 6 focuses on work done to study free charge in EDLTs through spectroscopic means. Chapter 7 explores the effects of ion volume on various EDLT performance metrics. Chapter 8 digs deeper into an interesting observation made in the work of Chapter 7 involving ion volume and EDLT threshold voltage ultimately leading to an examination of the effects of ion adsorption on threshold voltage. This work is but a drop in the bucket required to gain a thorough understanding of these exceedingly complex systems, and Chapter 9 covers the many avenues of continued research that exist

Conscientiousness in the Classroom: A Process Explanation

Although the research literature has established that Conscientiousness predicts task performance across a variety of achievement contexts (e.g., Barrick & Mount, 1991; OﾒConnor & Paunonen, 2007), comparatively less is known about the processes that underlie these relations. To the latter end, the current research examines effortful strategies and achievement goals as mediating factors that might explain why people with higher levels of Conscientiousness are predicted to reach higher levels of academic performance. In a longitudinal study, 347 college students completed measures of personality and achievement goals at the beginning of the class, followed by measures of effortful strategies multiple times throughout the semester. Results support the hypothesis that effortful strategies mediate the association between Conscientiousness and academic performance. Moreover, the statistical effects of Conscientiousness were generally independent of achievement goals, but a small portion of the effect was mediated through approach, not avoidance, achievement goals. These results highlight the importance of examining mediating processes between personality and outcomes, and in the case of Conscientiousness, our results suggest that effortful strategies might serve as a useful target for performance-enhancing interventions. Intelligence and hard work are often viewed as two essential ingredients for success in achievement contexts such as school and work. Consistent with this intuition, there is a well-established literature focusing on the connections between intelligence and performance (e.g., Judge, Higgins, Thoresen, & Barrick, 1999; Schmidt & Hunter, 1998), and a more recent history of research has pointed to the importance of Conscientiousness as a predictor of job performance that is relatively independent of intelligence (e.g., Barrick & Mount, 1991; Judge et al.,1999; Judge, Klinger, Simon, & Yang, 2008; Noftle & Robins, 2007; Roberts, Kuncel, Shiner, Caspi, & Goldberg, 2007). Turning to the academic context, a recent meta-analysis found that Conscientiousness, in fact, was the only practically significant personality predictor of postsecondary performance (OﾒConnor & Paunonen, 2007). Additional research is now required to understand why Conscientiousness predicts outcomes by identifying and modeling the mediating mechanisms between Conscientiousness and academic performance outcomes. In the current study, we propose that Conscientiousness is related to the types of goals, study strategies, and work habits that in turn promote success in academic contexts. We test this proposed process-based explanation using longitudinal data collected from college students. Our perspective is informed by McAdams and Pals's (2006) integrative personality framework, which identifies three major levels of personality. The first level, dispositional traits, is probably the most dominant approach in contemporary personality psychology. This level captures ﾓbroad individual differences in behavior, thought, and feeling that account for general consistencies across situations and over timeﾔ (p. 212). The second level, characteristic adaptations, incorporates social-cognitive variables such as goals that are ﾓcontextualized in time, situations, and social rolesﾔ (p. 212). The third and most fine-grained level addresses life narratives, or the construction of life stories and the development of individual identities. Our investigation focuses on the first two levels, in that we use constructs from the achievement goal literature to help explain how Conscientiousness (a dispositional or trait construct) is linked with academic outcomes. Formulating process models that bridge these two levels provides an opportunity to develop a more integrative understanding by moving beyond the study of simple trait-to-outcome correlations in the domains of personality and educational research

Jeff-CHAT Offers students an Interprofessional Forum to Discuss Experiences

Feelings of frustration, loss, and exhaustion are common among healthcare workers. Students placed among new experiences and in a dependent learning role are not shielded from these emotions but often experience them differently from other members of the healthcare team. In addition to the systematic and individual support available through TJUH, for the past year and a half Jeff‐ CHAT (Compassion, Humanism, Altruism, Trust) has provided a forum for students to discuss and reflect on difficult emotions and situations

Initial Vibration Analysis of the Advanced Stirling Radioisotope Generator's (ASRG's) Affect on Spacecraft Instruments

Assess if nominal Advanced Stirling Radioisotope Generator (ASRG) vibration levels are sufficiently benign for unimpeded spacecraft instrument operation

On the reliability of negative heat capacity measurements

A global protocol for the thermostatistical analysis of hot nuclear sources is discussed. Within our method of minimization of variances we show that the abnormal kinetic energy fluctuation signal recently reported in different experimental data (M.D'Agostino et al.-Phys. Lett. B 473 (2000) 219, N. Le Neindre et al.- contr. to the XXXVIII Bormio Winter Meeting on Nucl. Phys. (2001) 404) is a genuine signal of a first order phase transition in a finite system.Comment: 15 Postscript figures, submitted to NUCL. Phys. A on 24-apr-200

Extending Color Psychology to the Personality Realm: Interpersonal Hostility Varies by Red Preferences and Perceptual Biases

The color psychology literature has made a convincing case that color is not just about aesthetics, but also about meaning. This work has involved situational manipulations of color, rendering it uncertain as to whether color-meaning associations can be used to characterize how people differ from each other. The present research focuses on the idea that the color red is linked to, or associated with, individual differences in interpersonal hostility. Across four studies (N = 376 undergraduates), red preferences and perceptual biases were measured along with individual differences in interpersonal hostility. It was found that (a) a preference for the color red was higher as interpersonal hostility increased, (b) hostile people were biased to see the color red more frequently than nonhostile people, and (c) there was a relationship between a preference for the color red and hostile social decision making. These studies represent an important extension of the color psychology literature, highlighting the need to attend to person-based, as well as situation-based, factors

Streptomyces Exploration is Triggered by Fungal Interactions and Volatile Signals

It has long been thought that the life cycle of Streptomyces bacteria encompasses three developmental stages: vegetative hyphae, aerial hyphae and spores. Here, we show interactions between Streptomyces and fungi trigger a previously unobserved mode of Streptomyces development. We term these Streptomyces cells ‘explorers’, for their ability to adopt a non-branching vegetative hyphal conformation and rapidly transverse solid surfaces. Fungi trigger Streptomyces exploratory growth in part by altering the composition of the growth medium, and Streptomyces explorer cells can communicate this exploratory behaviour to other physically separated streptomycetes using an airborne volatile organic compound (VOC). These results reveal that interkingdom interactions can trigger novel developmental behaviours in bacteria, here, causing Streptomyces to deviate from its classically-defined life cycle. Furthermore, this work provides evidence that VOCs can act as long-range communication signals capable of propagating microbial morphological switches

Changes in global ocean bottom properties and volume transports in CMIP5 models under climate change scenarios

Changes in bottom temperature, salinity and density in the global ocean by 2100 for CMIP5 climate models are investigated for the climate change scenarios RCP4.5 and RCP8.5. The mean of 24 models shows a decrease in density in all deep basins except the North Atlantic which becomes denser. The individual model responses to climate change forcing are more complex: regarding temperature, the 24 models predict a warming of the bottom layer of the global ocean; in salinity, there is less agreement regarding the sign of the change, especially in the Southern Ocean. The magnitude and equatorward extent of these changes also vary strongly among models. The changes in properties can be linked with changes in the mean transport of key water masses. The Atlantic Meridional Overturning Circulation weakens in most models and is directly linked to changes in bottom density in the North Atlantic. These changes are due to the intrusion of modified Antarctic Bottom Water, made possible by the decrease in North Atlantic Deep Water formation. In the Indian, Pacific and South Atlantic, changes in bottom density are congruent with the weakening in Antarctic Bottom Water transport through these basins. We argue that the greater the 1986-2005 meridional transports, the more changes have propagated equatorwards by 2100. However, strong decreases in density over 100 years of climate change cause a weakening of the transports. The speed at which these property changes reach the deep basins is critical for a correct assessment of the heat storage capacity of the oceans as well as for predictions of future sea level rise

Recombination of Geminate (OH,eaq-) Pairs in Concentrated Alkaline Solutions: Lack of Evidence For Hydroxyl Radical Deprotonation

Picosecond dynamics of hydrated electrons and hydroxyl radicals generated in 200 nm photodissociation of aqueous hydroxide and 400 nm (3-photon) ionization of water in concentrated alkaline solutions were obtained. No deprotonation of hydroxyl radicals was observed on sub-nanosecond time scale, even in 1-10 M KOH solutions. This result is completely at odds with the kinetic data for deprotonation of OH radical in dilute alkaline solutions. We suggest that the deprotonation of hydroxyl radical is slowed down dramatically in concentrated alkaline solutions.Comment: 12 pages; 2 figures; submitted to Chem. Phys. Let

Spin oscillations in transient diffusion of a spin pulse in n-type semiconductor quantum wells

By studying the time and spatial evolution of a pulse of the spin polarization in $n$-type semiconductor quantum wells, we highlight the importance of the off-diagonal spin coherence in spin diffusion and transport. Spin oscillations and spin polarization reverse along the the direction of spin diffusion in the absence of the applied magnetic field are predicted from our investigation.Comment: 5 pages, 4 figures, accepted for publication in PR