Electron-phonon interaction toward engineering carrier mobility of periodic edge structured graphene nanoribbons.

Graphene nanoribbons have many extraordinary electrical properties and are the candidates for semiconductor industry. In this research, we propose a design of Coved GNRs with periodic structure ranged from 4 to 8 nm or more, of which the size is within practical feature sizes by advanced lithography tools. The carrier transport properties of Coved GNRs with the periodic coved shape are designed to break the localized electronic state and reducing electron-phonon scattering. In this way, the mobility of Coved GNRs can be enhanced by orders compared with the zigzag GNRs in same width. Moreover, in contrast to occasional zero bandgap transition of armchair and zigzag GNRs without precision control in atomic level, the Coved GNRs with periodic edge structures can exclude the zero bandgap conditions, which makes practical the mass production process. The designed Coved-GNRs is fabricated over the Germanium (110) substrate where the graphene can be prepared in the single-crystalline and single-oriented formants and the edge of GNRs is later repaired under "balanced condition growth" and we demonstrate that the propose coved structures are compatible to current fabrication facility.

Effectiveness of two forms of feedback on training of a joint mobilization skill by using a joint translation simulator.

BACKGROUND AND PURPOSE: Joint mobilization is a complicated task to learn and to teach and is characterized by great intersubject variability. This study's purpose was to investigate whether quantitatively augmented feedback could enhance the learning of joint mobilization and, more specifically, to compare the effects of training with concurrent or terminal feedback by using a joint translation simulator (JTS). SUBJECTS: Thirty-six undergraduate physical therapist students were randomly assigned to control (no feedback), concurrent feedback, and terminal feedback groups. METHODS: The JTS was designed to simulate tissue resistance based on load-displacement relationships of glenohumeral joint specimens. Subjects applied specific mobilization grades of force on the JTS while quantitative feedback was given to the feedback groups either during a trial (ie, concurrent feedback) or after a trial (ie, terminal feedback). The skill acquisition phase lasted a total of 40 minutes, and a total of 75 repetitions were performed for each grade of each joint model. Pretest and no-feedback retention tests were conducted. RESULTS: During acquisition and retention, both feedback groups performed more accurately than did the control group. No obviously superior performance was shown by the terminal feedback group compared with concurrent feedback group during retention testing. DISCUSSION AND CONCLUSION: Subjects who trained with augmented feedback had less variability, and thus more consistency, than the control group subjects who received no feedback. Augmented feedback provides the student with a reference force and the status of his or her performance. The effectiveness of the JTS feedback compared with no feedback was clearly demonstrated. Skill acquisition in mobilization can be enhanced by either concurrent or terminal feedback.