1,506 research outputs found
A quantitative study of bias triangles presented in chemical potential space
Full text linkWe present measurements of bias triangles in several biasing configurations. Using a capacitive model and two fit parameters we are able to predict the shapes and locations of the bias triangles in all measurement configurations. Furthermore, analysis of the data using this model allows us to present data from all four possible bias configurations on a single plot in chemical potential space. This presentation allows comparison between different biasing directions to be made in a clean and straightforward manner. Our analysis and presentation will prove useful in demonstrations of Pauli-spin blockade where comparisons between different biasing directions are paramount. The long term stability of the CMOS compatible Si/SiO2 only architecture leads to the success of this analysis. We also propose a simple variation to this analysis that will extend its use to systems lacking the long term stability of these devices. Justin K Perron, M D Stewart Jr, and Neil M Zimmerman. A quantitative study of bias triangles presented in chemical potential space, Journal of Physics: Condensed Matter, 27, (23), 235302 (2015). Creative Commons Attribution Non-Commercial No Derivatives LicenseJustin K Perron, M D Stewart Jr, and Neil M Zimmerman. A quantitative study of bias triangles presented in chemical potential space, Journal of Physics: Condensed Matter, 27, (23), 235302 (2015)0953-898
Facing the Future: the Changing Shape of Academic Skills Support at Bournemouth University
No full textThis paper explores the potential impact of changes to higher education in England on student expectations, engagement, lifestyles and diversity, and outlines implications for the development of digital literacy within academic skills support at Bournemouth University (BU). We will investigate how tackling resource constraints with organisational change can also enable efficient, centralised provision of support materials that utilise networks to overcome the risk of fragmented support for digital literacy. We will also look at how changing delivery modes for support can accommodate changing student lifestyles whilst tackling a weakness of centralised support for digital literacy: that it can become detached from the student’s subject-focused academic practice. Finally we will explore how involving students in developing support can help us to face changes to student expectations and engagement whilst ensuring that materials are authentic and speak to learners in their own voice
Why Privacy Matters: An Interview with Neil Richards
No full textProfessor Daniel J. Solove discusses the book \u27Why Privacy Matters\u27 and the future of privacy with the author, Professor Neil Richards
Maximizing Research Impact Through Institutional and National Open-Access Self-Archiving Mandates
No full textNo research institution can afford all the journals its researchers may need, so all articles are losing research impact (usage and citations). Articles made “Open Access,” (OA) by self-archiving them on the web are cited twice as much, but only 15% of articles are being spontaneously self-archived. The only institutions approaching 100% self-archiving are those that mandate it. Surveys show that 95% of authors will comply with a self-archiving mandate; the actual expe-rience of institutions with mandates has confirmed this. What institutions and funders need to mandate is that (1) immediately upon acceptance for publication, (2) the author’s final draft must be (3) deposited into the Institutional Repository. Only the depositing needs to be mandated; set-ting access privileges to the full-text as either OA or Restricted Access (RA) can be left up to the author. For articles published in the 93% of journals that have already endorsed self-archiving, access can be set as OA immediately; for the remaining 7%, authors can email the eprint in re-sponse to individual email requests automatically forwarded by the Repository
Valley blockade in a silicon double quantum dot
Full text linkElectrical transport in double quantum dots (DQDs) illuminates many interesting features of the dots' carrier states. Recent advances in silicon quantum information technologies have renewed interest in the valley states of electrons confined in silicon. Here we show measurements of dc transport through a mesa-etched silicon double quantum dot. Comparing bias triangles (i.e., regions of allowed current in DQDs) at positive and negative bias voltages we find a systematic asymmetry in the size of the bias triangles at the two bias polarities. Asymmetries of this nature are associated with blocked tunneling events due to the occupation of a metastable state. Several features of our data lead us to conclude that the states involved are not simple spin states. Rather, we develop a model based on selective filling of valley states in the DQD that is consistent with all of the qualitative features of our data.Justin K. Perron, Michael J. Gullans, Jacob M. Taylor, M. D. Stewart, Jr., and Neil M. Zimmerman. Valley blockade in a silicon double quantum dot, Physical Reveiw B, 96, 205302 Published 13 November (2017).2469-995
Dissimilarity is used as evidence of category membership in multidimensional perceptual categorization: a test of the similarity-dissimilarity generalized context model
Full text linkIn exemplar models of categorization, the similarity between an exemplar and category members constitutes evidence that the exemplar belongs to the category. We test the possibility that the dissimilarity to members of competing categories also contributes to this evidence. Data were collected from two 2-dimensional perceptual categorization experiments, one with lines varying in orientation and length and the other with coloured patches varying in saturation and brightness. Model fits of the similarity-dissimilarity generalized context model were used to compare a model where only similarity was used with a model where both similarity and dissimilarity were used. For the majority of participants the similarity-dissimilarity model provided both a significantly better fit and better generalization, suggesting that people do also use dissimilarity as evidence
Application of Analog Adaptive Filters for Dynamic Sensor Compensation
No full textThis paper investigates the application of analog adaptive techniques to the area of dynamic sensor compensation, of which there is little reported work in the literature. The case is illustrated by showing how the response of a load cell can be improved to speed up the process of measurement. The load cell is a sensor with an oscillatory output in which the measurand contributes to the response parameters. Thus, a compensation filter needs to track variation in measurand whereas a simple, fixed filter is only valid at one specific load value. To facilitate this investigation, computer models for the load cell and the adaptive compensation filter have been developed. To allow a practical implementation of the adaptive techniques, a novel piecewise linearization technique is proposed in order to vary a floating voltage-controlled resistor in a linear manner over a wide range. Simulation and practical results are presented, thus demonstrating the effectiveness of the proposed techniques
The Total Synthesis of Dragmacidins D and F
Full text linkThe dragmacidins are an emerging class of bis(indole) natural products isolated from deep-water marine organisms. Although there has been a substantial effort to prepare the simple piperazine dragmacidins, little synthetic work has been done in the area of the pyrazinone-containing family members, dragmacidins D, E, and F. These compounds are particularly interesting due to their complex structures and broad range of biological activity.
A highly convergent strategy to access dragmacidin D has been developed. In this approach, sequential halogen-selective Suzuki couplings were used to assemble the carbon scaffold of the natural product. After executing a highly optimized sequence of final events, the first completed total synthesis of dragmacidin D was achieved.
An enantiodivergent strategy for the total chemical synthesis of both (+)- and (-)-dragmacidin F from a single enantiomer of quinic acid has been developed and successfully implemented. Although unique, the synthetic routes to these antipodes share a number of key features, including novel reductive isomerization reactions, Pd(II)-mediated oxidative carbocyclization reactions, halogen-selective Suzuki couplings, and high-yielding late-stage Neber rearrangements.
The formal total syntheses of dragmacidin B, trans-dragmacidin C, and dihydrohamacanthin A are described. In addition, preliminary studies involving a novel approach for the preparation of dragmacidin E are reported.</p
Millisecond accuracy video display using OpenGL under Linux
Full text linkTo measure people’s reaction times to the nearest millisecond, it is necessary to know exactly when
a stimulus is displayed. This article describes how to display stimuli with millisecond accuracy on a
normal CRT monitor, using a PC running Linux. A simple C program is presented to illustrate how this
may be done within X Windows using the OpenGL rendering system. A test of this system is reported
that demonstrates that stimuli may be consistently displayed with millisecond accuracy. An algorithm
is presented that allows the exact time of stimulus presentation to be deduced, even if there are relatively
large errors in measuring the display time
Hearing Faces and Seeing Voices: The Integration and Interaction of Face and Voice Processing
Full text linkCognitive understanding of voice recognition has borrowed much from the area of face processing, both in terms of the theoretical framework within which results are interpreted, and the methodology used to assess performance. A considerable body of research now exists to suggest that voice recognition may proceed in parallel with face recognition, and that the two pathways may combine to inform person recognition. However, rather than being independent or equivalent, these parallel pathways appear to interact to reveal interesting interference effects. The present paper reviews a series of studies that focus on a considerable and growing literature. The vulnerability of voice processing will be explored relative to face processing, and the interaction of these two pathways will be examined with reference to broader theoretical frameworks for person recognition
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