Probing energy barriers and quantum confined states of buried semiconductor heterostructures with ballistic carrier injection: An experimental study

A three-terminal spectroscopy that probes both subsurface energy barriers and interband optical transitions in a semiconductor heterostructure is demonstrated. A metal-base transistor with a unipolar p-type semiconductor collector embedding InAs/GaAs quantum dots (QDs) is studied. Using minority/majority carrier injection, ballistic electron emission spectroscopy and its related hot-carrier scattering spectroscopy measures barrier heights of a buried AlxGa1-xAs layer in conduction band and valence band respectively, the band gap of Al0.4Ga0.6As is therefore determined as 2.037 +/- 0.009 eV at 9 K. Under forward collector bias, interband electroluminescence is induced by the injection of minority carriers with sub-bandgap kinetic energies. Three emission peaks from InAs QDs, InAs wetting layer, and GaAs are observed in concert with minority carrier injection.Comment: 11 pages, 4 figures, submitted to Physical Review

Automated Analysis, Classification, and Display of Waveforms

A computer program partly automates the analysis, classification, and display of waveforms represented by digital samples. In the original application for which the program was developed, the raw waveform data to be analyzed by the program are acquired from space-shuttle auxiliary power units (APUs) at a sampling rate of 100 Hz. The program could also be modified for application to other waveforms -- for example, electrocardiograms. The program begins by performing principal-component analysis (PCA) of 50 normal-mode APU waveforms. Each waveform is segmented. A covariance matrix is formed by use of the segmented waveforms. Three eigenvectors corresponding to three principal components are calculated. To generate features, each waveform is then projected onto the eigenvectors. These features are displayed on a three-dimensional diagram, facilitating the visualization of the trend of APU operations

Scattering-Assisted Tunneling: Energy Dependence, Magnetic Field Dependence, and Use as an External Probe of Two-Dimensional Transport

For more than three decades, research on tunneling through planar barriers has focused principally on processes that conserve momentum parallel to the barrier. Here we investigate transport in which scattering destroys lateral momentum conservation and greatly enhances the tunneling probability. We have measured its energy dependence using capacitance spectroscopy, and we show that for electrons confined in a quantum well, the scattering enhancement can be quenched in an applied magnetic field, enabling this mechanism to function as an external probe of the origin of the quantum Hall effect.Engineering and Applied Science

President’s Column (2015) 50 Page 111

It has been my privilege to represent the American Judges Association at a great many meetings and conferences over the past year. Our organization is widely respected. The organization and its leadership are acknowledged as an effective “Voice of the Judiciary®,” for “Making Better Judges®,” for high-quality conferences, for excellent judicial-education programs, and for the developing AJA brand in the area of procedural fairness. At our midyear meeting in May, the new Arizona Chief Justice, Scott Bales, particularly commented on the value of Court Review, our quarterly journal, as a scholarly yet practical tool for judges at all levels to learn more about cutting-edge topics such as those in this edition. During the many conversations I’ve had with judicial leaders, I’ve often heard the statement, “We need to collaborate.” AJA is establishing itself as an important collaborator in the constellation of organizations seeking to improve access to fair and impartial justice for all

President’s Column: WE’RE IN TOUCH, SO YOU BE IN TOUCH

It is a privilege and honor to begin my term as your president, especially at a time when AJA is so well respected and highly regarded as the largest judge-only organization in North America. As I write, I have recently returned from the fantastic 53rd education conference in Hawaii where we were honored by welcoming letters from Hawaii Governor Neil Abercrombie, U.S. Senator Brian Schatz, and U.S. Representative Colleen Hanabusa. Hawaii Chief Justice Mark Recktenwald came in person to open the conference. If you missed this uplifting event and the chance to interact with more than 150 of the best judges in North America and the stellar faculty of 29 distinguished experts in their respective fields, take a moment to go to the “Conference” section of our website (www.amjudges.org) to explore the educational materials from the conference. You too will be proud to say that you are an AJA member! During the business meetings in Hawaii, the members of the Executive Committee and the Board of Governors had a chance to review AJA’s current statement of purpose, which is “to promote and improve the effective administration of justice; to maintain the status and independence of the judiciary; to provide a forum for the continuing education of its members and the general public; and for the exchange of new ideas among all judges.

Transforming pedagogical frontiers- harnessing the potential of school libraries as catalysts for teacher professional development: Reflections from six rural schools

Generally, school libraries serve the purpose of promoting a culture of reading among users and creating environments that foster literacy. They achieve this by offering reading materials that are relevant and appealing to individuals of all ages. School libraries play a crucial role in facilitating quality teaching and learning, thereby positively impacting student achievement. Recognising the influential role of educators in shaping students' learning experiences and the specific challenges faced by those in rural settings, this qualitative case study research investigates the potential of school libraries as centres for teacher professional support, aiming to improve instructional practices. The study reflects on the experiences of three primary and three secondary schools purposefully selected from a South African rural education district. Through the use of Google Forms and semi-structured interviews, the data revealed that school libraries serve as dynamic hubs that foster professional growth among teachers, enhance lesson preparation, promote learner engagement, create learner-centred environments, and address resource disparities. The research concludes that incorporating school libraries as vibrant professional hubs in rural educational settings is essential for advancing teacher pedagogy, ultimately contributing to a more inclusive and effective learning environment. Therefore, the study advocates for the prioritisation of school library availability to enhance overall teacher pedagogy in rural educational landscapes

Using ADDIE model for scaffolded learning and teaching intervention

Learning and Teaching (L&T) research is sometimes challenging for lecturers who are not specialists in the Scholarship of Teaching and Learning (SoTL) or instructional design. Good empirical L&T research should be reflective, based on a sound theoretical foundation, and completed like other research, using appropriate steps in data collection. Many L&T researchers often skip to the intervention or implementation without embedding evidence and proper research steps in the project from the beginning. This study aimed to explore the integration of the ADDIE model with L&T interventions incorporating pedagogical theory. It also aimed to examine how the findings from implementing this model in SoTL projects can inform best practices for instructional design and contribute to the broader scholarship on teaching and learning. The study adopted a mixed-method approach with a pre-post-test design. A collaborative interventive research project was purposively selected, focusing on First Year, Senior, and Further Education and Training (SEN&FET) Bachelor of Education students who are trained to teach grades 8-12. The results confirmed the efficacy of the ADDIE model steps as a useful instructional design framework for integrating L&T theories. The study also found that a scaffolded L&T collaborative intervention with sound research methodologies and approaches is beneficial for SoTL projects. Therefore, the study recommends implementing the ADDIE model in different interventive approaches and collaborative educational settings to enhance students' achievement as well as teaching and learning

Analyse temporelle et sémantique des réseaux sociaux typés à partir du contenu de sites généré par des utilisateurs sur le Web

We propose an approach to detect topics, overlapping communities of interest, expertise, trends andactivities in user-generated content sites and in particular in question-answering forums such asStackOverFlow. We first describe QASM (Question & Answer Social Media), a system based on socialnetwork analysis to manage the two main resources in question-answering sites: users and contents. Wealso introduce the QASM vocabulary used to formalize both the level of interest and the expertise ofusers on topics. We then propose an efficient approach to detect communities of interest. It relies onanother method to enrich questions with a more general tag when needed. We compared threedetection methods on a dataset extracted from the popular Q&A site StackOverflow. Our method basedon topic modeling and user membership assignment is shown to be much simpler and faster whilepreserving the quality of the detection. We then propose an additional method to automatically generatea label for a detected topic by analyzing the meaning and links of its bag of words. We conduct a userstudy to compare different algorithms to choose the label. Finally we extend our probabilistic graphicalmodel to jointly model topics, expertise, activities and trends. We performed experiments with realworlddata to confirm the effectiveness of our joint model, studying the users’ behaviors and topicsdynamicsNous proposons une approche pour détecter les sujets, les communautés d'intérêt non disjointes,l'expertise, les tendances et les activités dans des sites où le contenu est généré par les utilisateurs et enparticulier dans des forums de questions-réponses tels que StackOverFlow. Nous décrivons d'abordQASM (Questions & Réponses dans des médias sociaux), un système basé sur l'analyse de réseauxsociaux pour gérer les deux principales ressources d’un site de questions-réponses: les utilisateurs et lecontenu. Nous présentons également le vocabulaire QASM utilisé pour formaliser à la fois le niveaud'intérêt et l'expertise des utilisateurs. Nous proposons ensuite une approche efficace pour détecter lescommunautés d'intérêts. Elle repose sur une autre méthode pour enrichir les questions avec un tag plusgénéral en cas de besoin. Nous comparons trois méthodes de détection sur un jeu de données extrait dusite populaire StackOverflow. Notre méthode basée sur le se révèle être beaucoup plus simple et plusrapide, tout en préservant la qualité de la détection. Nous proposons en complément une méthode pourgénérer automatiquement un label pour un sujet détecté en analysant le sens et les liens de ses mots-clefs.Nous menons alors une étude pour comparer différents algorithmes pour générer ce label. Enfin, nousétendons notre modèle de graphes probabilistes pour modéliser conjointement les sujets, l'expertise, lesactivités et les tendances. Nous le validons sur des données du monde réel pour confirmer l'efficacité denotre modèle intégrant les comportements des utilisateurs et la dynamique des sujet

Near-infrared absorption and semimetal-semiconductor transition in 2 nm ErAs nanoparticles embedded in GaAs and AlAs

Journal ArticleWe report strong near-infrared absorption peaks in epitaxial films of GaAs and AlAs containing approximately 0.5-5% of the semimetal ErAs. The energy of the resonant absorption peak can be changed from 0.62 to 1.0 eV (2.2-1.4 μm) by variation of the ErAs volume fraction and the substrate temperature. We interpret the infrared absorption in terms of transitions across an energy gap caused by a confinement-induced semimetal-semiconductor transition. An effective mass model relates the changes in nanoparticle diameter observed in transmission electron microscopy to the energy gap