Synthesis,morphology and device characterizations of a new organic semiconductor based on 2,6-diphenylindenofluorene

A new organic semiconductor, 2,6-diphenylindenofluorene (DPIF), was synthesized in four steps with a high overall yield of 49.3%. The morphology of thin films of DPIF that were formed under different substrate temperatures was examined by atomic force microscopy and X-ray diffraction analysis. Two different crystalline phases were found to exist depending on the deposition conditions. The DPIF thin film emits around 500–530 nm, while the OLED based on DPIF emits green light with a maximum output over 150 Cd/m² under 35 V. Two typical transistor devices, thin-film transistor (TFT) and semiconductor-metal-semiconductor (SMS) transistor, were fabricated and characterized. DPIF shows a weak n-type character from the TFT device measurement, while SMS transistors using DPIF as an emitter behave like permeable-base transistors with low operating voltages in both common-base and common-emitter modes and a feature of current amplification. Our results demonstrate however, that further research efforts are necessary in order to prevent the observed instabilities. These are quite important, considering that the common-emitter mode is widely used in applications requiring not only switching capability, but also current amplification.     

Property and microstructure evaluation as a function of processing parameters: Large HY-80 steel casting for a US Navy submarine

Processing techniques can significantly alter the properties of a material and can ultimately determine whether a component will perform its function safely. This effort involves the investigation of the processing parameters of HY-80 steel castings; specifically a large HY-80 submarine casting that failed while in service due to improper processing. Samples taken from the failed casting were evaluated in the as-received condition and after exposures to various improper quench and temper scenarios that were possible during casting production. Microstructural examination and hardness measurements were used to evaluate the condition of the high strength steel and these results were correlated to Charpy impact toughness. One important result of this work indicates that hardness alone is not a good indication of material condition: the same measured hardness values yielded very different fracture behavior. The window of favorable processing parameters as defined by heat treatment temperature was clarified based on the specification requirements set by the US Navy for HY-80 castings.     

Performance implications of leader briefings and team-interaction training for team adaptation to novel environments.

The authors examined how leader briefings and team-interaction training influence team members' knowledge structures concerning processes related to effective performance in both routine and novel environments. Two-hundred thirty-seven undergraduates from a large mid-Atlantic university formed 79 three-member tank platoon teams and participated in a low-fidelity tank simulation. Team-interaction training, leader briefings, and novelty of performance environment were manipulated. Findings indicated that both leader briefings and team-interaction training affected the development of mental models, which in turn positively influenced team communication processes and team performance. Mental models and communication processes predicted performance more strongly in novel than in routine environments. Implications for the role of team-interaction training, leader briefings, and mental models as mechanisms for team adaptation are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning mathematics in first-grade classrooms: On whose authority?

Integral to knowing mathematics is an understanding of how mathematical ideas are generated and validated. In mathematics classrooms, teachers socialize this understanding by establishing discourse patterns and participatory structures in which various sources-the teacher, the text, the discipline of mathematics, or the community of learners--are implicitly and explicitly credited with the authority to develop and validate mathematical ideas. In the present investigation, the authors focused on classroom discourse processes and participatory structures that grant sources of mathematical authority in 6 first-grade classrooms. In general, teachers firmly and with few exceptions positioned themselves as the sole mathematical authority in their classrooms. Yet, the authors found significant exceptions in 1 teacher's lessons, with these exceptions inspiring possibilities in accomplishing the shift from a formal to a growth-and-change tradition of socializing students into the discipline of mathematics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lateralization of perinatal cerebral insult and cognitive asymmetry: Evidence from neuroimaging.

The current investigation incorporated 2 studies. The objective of Study 1 was to explore lateralizalion of cerebral insult in the preterm neonate. To attain this goal, the radiological records of 148 premature infants with intracranial hemorrhage were retrospectively reviewed. Statistical analyses revealed that the lesion tended to be observed initially in the left hemisphere. Bilateral hemorrhage tended to be asymmetrical, with more pathological changes observed on the left. Study 2 examined the cognitive outcome of unilateral hemorrhage in a subsample of 20 children. Analyses revealed a link between lateralization of hemorrhage and pattern of cognitive asymmetry. Possible origins of increased left hemisphere vulnerability and implications of the reported cognitive changes for the onset of hemispheric specialization are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predicting workplace aggression: A meta-analysis.

The authors conducted a meta-analysis of 57 empirical studies (59 samples) concerning enacted workplace aggression to answer 3 research questions. First, what are the individual and situational predictors of interpersonal and organizational aggression? Second, within interpersonal aggression, are there different predictors of supervisor- and coworker-targeted aggression? Third, what are the relative contributions of individual (i.e., trait anger, negative affectivity, and biological sex) and situational (i.e., injustice, job dissatisfaction, interpersonal conflict, situational constraints, and poor leadership) factors in explaining interpersonal and organizational aggression? Results show that both individual and situational factors predict aggression and that the pattern of predictors is target specific. Implications for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

True and false memories in children and adults: A cognitive neuroscience perspective.

The authors consider evidence concerning accuracy and distortion in children's recollections within the broader context of recent research on memory that has used the methods and conceptual framework of cognitive neuroscience. They focus on 3 phenomena (source amnesia, confabulation, and false recognition) that have been observed in young children and in adults who have sustained damage to the frontal lobes. Similarities and differences between the memory performance of young children and frontal lobe patients are noted, and evidence concerning frontal lobe maturation and cognitive development is examined. The literature provides suggestive but not conclusive support for the hypothesis that some aspects of memory development and cognitive development are associated with immature frontal functioning. The authors conclude by considering several cognitive and temperamental factors that may be related to suggestibility and memory distortion in young children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Architecture and Design of 1-D Enhanced Cellular Neural Network Processors for Signal Detection

One-dimensional cellular array processor architecture and design for neural-based partial response (PR) signal detection are presented. Analog parallel computing approaches have many attractive advantages in achieving low power, low cost, and faster processing speed by its uniquely coupled parallel and distributed processing nature. In this paper, we describe the maximum likelihood sequence estimation (MLSE) algorithm for PR signals, the enhanced Cellular Neural Network (CNN) processor array architecture to realize the detection algorithm, and system performance evaluation. Analytical models and simulations on a design example of the detector have been employed to demonstrate the advantages of this scalable VLSI architecture. A processing rate of 265 Mbps was achieved for a prototype detector on a silicon area of 5.14 mm by 5.81 mm is a 1.2 µm CMOS technology. The processing rate can be beyond 1Gbps if it is implemented in the same amount of silicon area by using 0.5 µm CMOS technology. Such promising results clearly demonstrate the ability to meet the needs in future high speed data communication by VLSI realization of maximum likelihood sequence detectors based on the enhanced cellular neural network paradigm.     

Training practices in consultation: A national survey of clinical, counseling, industrial/organizational, and school psychology faculty.

Faculty who educate and train psychology students in consulting from clinical, counseling, school, and industrial/organizational graduate programs were identified via mail from department chairs and program directors. Of 197 faculty members identified, 89 (46.9% response rate) completed a detailed survey questionnaire about demographics and professional consulting activities, including teaching practices in consulting in their graduate program. Results were somewhat encouraging within industrial/organizational and school psychology programs and least positive in counseling/clinical programs, especially clinical programs. Detailed results are presented along with some implications for future graduate training in consulting psychology. A call is made for convening a national conference on educational standards in consulting psychology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)