Theoretical Rationalization of the Singlet–Triplet Gap in OLEDs Materials: Impact of Charge-Transfer Character

New materials for OLED applications with low singlet–triplet energy splitting have been recently synthesized in order to allow for the conversion of triplet into singlet excitons (emitting light) via a Thermally Activated Delayed Fluorescence (TADF) process, which involves excited-states with a non-negligible amount of Charge-Transfer (CT). The accurate modeling of these states with Time-Dependent Density Functional Theory (TD-DFT), the most used method so far because of the favorable trade-off between accuracy and computational cost, is however particularly challenging. We carefully address this issue here by considering materials with small (high) singlet–triplet gap acting as emitter (host) in OLEDs and by comparing the accuracy of TD-DFT and the corresponding Tamm-Dancoff Approximation (TDA), which is found to greatly reduce error bars with respect to experiments thanks to better estimates for the lowest singlet–triplet transition. Finally, we quantitatively correlate the singlet–triplet splitting values with the extent of CT, using for it a simple metric extracted from calculations with double-hybrid functionals, that might be applied in further molecular engineering studies.

Investigation of un-American propaganda activities in the United States : Hearings before a Special Committee on Un-American Activities, House of Representatives, Seventy-fifth Congress, third session-Seventy-eighth Congress, second session, on H. Res. 282, to investigate (1) the extent, character, and objects of un-American propaganda activities in the United States, (2) the diffusion within the United States of subversive and un-American propaganda that is instigated from foreign countries or of a domestic origin and attacks the principle of the form of government as guaranteed by our Constitution, and (3) all other questions in relation thereto that would aid Congress in any necessary remedial legislation.

Martin Dies, chairman.

Perceptions of Character Education in a Seventh-Day Adventist School

Character education has been viewed by many educators as having significant historical, academic, and social value. Many stakeholders in education argue for character development as a curricular experience. While understanding the degree to which character education is of worth to stakeholders of institutions is important, understanding students, teachers, and administrators perspectives from their lived experiences is likewise significant. The purpose of this phenomenological study was to gain a deeper understanding of character education within a Biblical framework environment by examining the lived experiences of students, administrators, and teachers of a Seventh-day Adventist School. Phenomenology describes individuals’ daily experiences of phenomena, the manner in which these experiences are structured, and focuses analysis on the perspectives of the persons having the experience (Moustakas, 1994). ). This inquiry was undertaken to answer the question: What are the perceptions of students, teachers, and an administrator toward character education in a Seventh-day Adventist school setting? Ten participants (seven students and three adults) formed the homogeneous purposive sample, and the major data collection tool was semi-structured interviews (Patton, 1990; Seidman, 2006). Three 90-minute open-ended interviews were conducted with each of the participants. Data analysis included a three-phase process of description, reduction and interpretation. The findings from this study revealed that participants perceived that their involvement in the school’s character education program decreased the tendency to violence, improved their conduct and ethical sensibility, enhanced their ability to engage in decision-making concerning social relationships and their impact on others, brought to their attention the emerging global awareness of moral deficiency, and fostered incremental progress from practice and recognition of vices to their acquisition of virtues. The findings, therefore, provide a model for teaching character education from a Seventh-day Adventist perspective. The model is also relevant for non-Seventh day Adventists who aspire to teach character education as a means to improving social and moral conditions in schools.

Goma Curriculum, A Character Education Paradigm: Composing a Text for Shaping Classroom Character Culture

The written text, and approaches to reading it, serves well as an analogy for the classroom space as a “text” that teachers are able to compose; and students are able to read, interpret meaning(s) of, and make responses to and about (Rosenblatt, 1988). Researchers point to ways in which the classroom can be conceptualized as a text to be evoked, experienced, and read (Freire & Macedo, 1987; Powell, 2009; Rosenblatt, 1988; Spears-Bunton & Powell, 2009). The present study analyzed secondary data including: 10 transcripts of teacher talks and six self-reports retrieved from the program evaluation archives of DOR Foundation. The data described six teachers’ classroom experiences subsequent to professional development centered on Goma character education curriculum that was used during a summer youth program located in South Georgia. Goma, an acronym that stands for Goal, Objective, Method, and Attitude, is a character education paradigm derived from The Inclusive Community Building Ellison Model, the theoretical framework used for this study. The Model identifies conflict resolution as one of its five foci (Hunt, Howard, & Rice, 1998). Hunt (2006) conceived Goma as part of a 7-Step unitary process, also named the 7-Step pathway, to demonstrate how conflict resolution is accomplished within a variety of contexts. Analysis of the data involved: (a) a priori coding of teacher talks transcripts using the components of the Goma 7-Step pathway as coding categories, (b) emergent coding of teacher talks transcripts for the types of experiences teachers evidenced, and (c) emergent coding of teachers’ self-reports for categories of teachers’ instructional activities. Results of the study showed positive influence of Goma curriculum on participating teachers and their instructional practices. Teachers were shown to have had cognitive, instructional, emotional, and social experiences that were most evident when they reported changes in their attitudes toward their students, themselves, and their instructional practices. The present study provided implications for classroom teachers wherein all aspects of teachers’ instructional practices can be guided by principles of positive character; and can be used to help compose the kinds of “texts” that may likely contribute to a classroom character culture.

E-polynomial of SL(2,C)-character varieties of complex curves of genus 3.

We compute the E-polynomials of the moduli spaces of representations of the fundamental group of a complex curve of genus g = 3 into SL(2, C), and also of the moduli space of twisted representations. The case of genus g = 1, 2 has already been done in [12]. We follow the geometric technique introduced in [12], based on stratifying the space of representations, and on the analysis of the behaviour of the E-polynomial under fibrations.

Character in Context: Informing Character Education Programming

The Positive Youth Development (PYD) perspective is a strength-based conceptualization of youth. It highlights the importance of mutually beneficial relationships between youth and their environment to develop the “Five Cs”, key assets that include character. Character has long been a subject of programming due to its focus on helping children lead moral, empathic, and prosocial lives. There are, however, many limitations in character research, including poorly operationalized definitions of character; a failure to examine the developmental and broader social context in which character exists; and a lack of evaluation of more practical character programming. The goal of this dissertation was to address these gaps in knowledge and inform the character education programming literature. The first study examined the relationships among age, gender, the school social context, and character. Moral character was negatively associated with grade, and being a girl was positively associated with moral character. The relationships between positive peer interactions at school and character (fairness, integrity) were stronger among students who reported low initial moral character when positive peer interactions was high. In the second study, the Build Character: Build Success Program, a character education program, was evaluated over six months to examine its effects on character behaviours, victimization, and school climate. No program effects were found for students in grades 1 to 3, but a slight decrease in victimization in one experimental school was found for students in grades 4 to 8. This lack of general program effects may be due to the short-term nature of the intervention, which may not have been long enough to result in measurable behaviour change. Implementation data indicated that teachers did not teach all program elements, which also may have influenced the results of the program evaluation. The present dissertation contributes to knowledge about character and its programming by: introducing new measures to operationalize character, discovering developmental patterns in character in school-aged children, highlighting gender differences in character, examining character within its broad social context, and evaluating short-term character education programming.