Engineering and Manipulating Exciton Wave Packets

When a semiconductor absorbs light, the resulting electron-hole superposition amounts to a uncontrolled quantum ripple that eventually degenerates into diffusion. If the conformation of these excitonic superpositions could be engineered, though, they would constitute a new means of transporting information and energy. We show that properly designed laser pulses can be used to create such excitonic wave packets. They can be formed with a prescribed speed, direction and spectral make-up that allows them to be selectively passed, rejected or even dissociated using superlattices. Their coherence also provides a handle for manipulation using active, external controls. Energy and information can be conveniently processed and subsequently removed at a distant site by reversing the original procedure to produce a stimulated emission. The ability to create, manage and remove structured excitons comprises the foundation for opto-excitonic circuits with application to a wide range of quantum information, energy and light-flow technologies. The paradigm is demonstrated using both Tight-Binding and Time-Domain Density Functional Theory simulations.Comment: 16 figure

User documentation for the MSK and OMS intelligent tutoring systems

This user's guide describes how to use the Intelligent Tutoring Systems for the Manual Select Keyboard (MSK) and the Orbital Maneuvering System (OMS) and how to use the C code that runs the mockup version of the MSK

Embedded Ribbons of Graphene Allotropes: An Extended Defect Perspective

Four fundamental dimer manipulations can be used to produce a variety of localized and extended defect structures in graphene. Two-dimensional templates result in graphene allotropes, here viewed as extended defects, which can exhibit either metallic or semiconducting electrical character. \emph{Embedded allotropic ribbons}--i.e. thin swaths of the new allotropes--can also be created within graphene. We examine these ribbons and find that they maintain the electrical character of their parent allotrope even when only a few atoms in width. Such extended defects may facilitate the construction of monolithic electronic circuitry.Comment: 24 pages, 21 figure

State of Maine Song

Text and music by Frances T. Wiggin. Arranged by Fred Lincoln Hill.https://digicom.bpl.lib.me.us/books_pubs/1242/thumbnail.jp

Midnight Fire-Alarm : Descriptive March-Galop

https://digitalcommons.library.umaine.edu/mmb-ps/2355/thumbnail.jp

Design Perspective on the Role of Advanced Bots for Self-Guided Learning

Virtual worlds are rapidly gaining acceptance in educational settings; with bots play an important role in these environments to help learners. Authentic learning can be significantly supported by bots to help self-guided learning in authentic tasks. in this paper, we investigate what is stopping educators from making more use of bots as a valuable resource and how these barriers can be overcome. This exploratory research uses interviews with six educators, who use educational bots. We show that while the experts have 'big plans' for bot use, the current educational implementations are 'low-level' and restrictive in their application. There is further confusion about appropriate pedagogical models and how to use them effectively as more than 'prompters' or 'extras'. While creation- and control-technologies are advancing, allowing use of bots as a 'hard technology' to guide learners through routine procedures; there is a lack of resources for automation as intelligence technologies are slower to develop and may required future partnerships with external parties before they are available useable by general educators

Primordia initiation of mushroom (Agaricus bisporus) strains on axenic casing materials

The mushroom (Agaricus bisporus) has a requirement for a ‘‘casing layer’’ that has specific physical, chemical and microbiological properties which stimulate and promote the initiation of primordia. Some of these primordia then may develop further into sporophores, involving differentiation of tissue. Wild and commercial strains of A. bisporus were cultured in axenic and nonaxenic microcosms, using a rye grain substrate covered by a range of organic and inorganic casing materials. In axenic culture, A. bisporus (commercial strain A15) was capable of producing primordia and mature sporophores on charcoal (wood and activated), anthracite coal, lignite and zeolite, but not on bark, coir, peat, rockwool, silica or vermiculite. Of six strains tested, only the developmental variant mutant, B430, produced rudimentary primordia on axenic peat-based casing material. However, none of these rudimentary primordia developed differentiated tissues or beyond 4 mm diameter, either on axenic casing material in the microcosms or in larger-scale culture. In larger-scale, nonaxenic culture, strain B430 produced severely malformed but mature sporophores in similar numbers to those of other strains. Typically, 3–6% of primordia developed into mature sporophores, but significant differences in this proportion, as well as in the numbers of primordia produced, were recorded between 12 A. bisporus strains

Building Local Capacity to Respond to Environmental Change: Lessons and Case Studies from New York State

CaRDI Reports Issue 1

Experimental study on consumer-technology supported authentic immersion in virtual worlds for education and vocational training

Despite significant and rapid technology improvements, educators have frequently failed to make use of the new opportunities to create more authentic learning scenarios. Virtual worlds offer an attractive proposition to create 3D representations of real business environments to provide an authentic learning activity for higher education students to take part in. However, the controls and displays are still clunky and unnatural, reducing the opportunity for students to immerse themselves in the event and focus on experiential learning. To overcome this challenge we examine the role of using a headset display that allows the user to change perspective with a flick of the head, improving their ability to ‘feel’ part of the environment, and thus increase their immersion in the activities that they are engaged in through more realistic control and improved perspective in the virtual environment. A series of experiments are conducted comparing the technology to established technologies and the level of control exerted by the learner (e.g., they either ‘control’ or they ‘passively observe’ as someone else controls). These experiments provide evidence that consumer-technology can improve immersion and equip educators with an affordable instrument to present classes that learners ‘take more seriously’