6,424 research outputs found
Measuring athlete imagery ability: the Sport Imagery Ability Questionnaire
Based on literature identifying movement imagery, observation, and execution to elicit similar areas of neural activity, research has demonstrated movement imagery and observation to successfully prime movement execution. To investigate whether movement and observation could prime ease of imaging from an external visual imagery perspective, an internal visual imagery perspective, and kinaesthetic modality, 36 participants (M = 20.58; SD = 3.11; 18 female, 18 male) completed the Movement Imagery Questionnaire-3 under four modes of delivery (movement prime, external observation prime, internal observation prime, and image-only). Results revealed ease of imaging was significantly greater during the movement and observation prime conditions compared to the image-only condition (p < .05). Specifically when priming external visual imagery and internal visual imagery, observation only facilitated ease of imaging when the perspective was congruent with the imagery perspective. Results support the utilization of movement and observation to facilitate ease of imaging, but highlight the importance of considering visual perspective when using observation
Radiation from ingested wireless devices in bio-medical telemetry bands
The performance of wireless devices, using electrically small antennae, in the human intestine is investigated using the finite difference time domain method in recommended biomedical device telemetry bands. The radiation field intensity was found to depend on position but more strongly on frequency, with a transmission peak at 650 MHz
Electromagnetic radiation from ingested sources in the human intestine between 150 MHz and 1.2 GHz
The conventional method of diagnosing disorders of the human gastro-intestinal (GI) tract is by sensors embedded in cannulae that are inserted through the anus, mouth, or nose. However, these cannulae cause significant patient discomfort and cannot be used in the small intestine. As a result, there is considerable ongoing work in developing wireless sensors that can be used in the small intestine. The radiation characteristics of sources in the GI tract cannot be readily calculated due to the complexity of the human body and its composite tissues, each with different electrical characteristics. In addition, the compact antennas used are electrically small, making them inefficient radiators. This paper presents radiation characteristics for sources in the GI tract that should allow for the optimum design of more efficient telemetry systems. The characteristics are determined using the finite-difference time-domain method with a realistic antenna model on an established fully segmented human body model. Radiation intensity outside the body was found to have a Gaussian-form relationship with frequency. Maximum radiation occurs between 450 and 900 MHz. The gut region was found generally to inhibit vertically polarized electric fields more than horizontally polarized fields
Electromagnetic radiation from ingested sources in the human intestine
There is currently considerable work on the development of wireless sensors that can be used in the small intestine. The radiation characteristics of sources in the gastro-intestinal (GI) tract cannot be readily calculated due to the complexity of the human body and its composite tissues, each with different electrical characteristics. This paper presents radiation characteristics for sources in the GI tract that should allow for the optimum design of more efficient telemetry systems. The characteristics are determined using the finite difference time domain method with a realistic antenna model on an established fully segmented human body model. Maximum radiation was found to occur between 450 and 900 MHz and the gut region was found generally to inhibit vertically polarized electric fields more than horizontally polarized fields
MOSAIC: An integrated ultrasonic 2-D array system
An investigation into the development of an ultrasound imaging system capable of customization for multiple applications via the tessellation of in-system programmable scalable modules, or tiles, is presented here. Each tile contains an individual ultrasonic array, operating at +/-3.3V, which can be assembled into a larger âmosaicâ of multiple tiles to create arrays of any size or shape. The ability to form an imaging system from generic building blocks which are physically identical for manufacturing purposes yet functionally unique via programming to suit the application has many potential benefits in the field of ultrasonics. The system is primarily targeted at underwater sonar and non-destructive testing, as defined by the current excitation frequency, but the concept is equally applicable to applications in biomedical ultrasound
Fabrication of submicron planar Gunn diode
We present, for the first time, the fabrication
process for a submicron planar Gunn diode in In<sub>0.53</sub>Ga<sub>0.47</sub>As on an InP substrate operating at 265 GHz. A novel two stage lift off method has been developed to achieve a submicron gaps between
contacts down to 135 nm with widths up to 120 ÎŒm
Spatial resilience in social-ecological systems
Spatial Resilience is a new and exciting area of interdisciplinary research. It focuses on the influence of spatial variation - including such things as spatial location, context, connectivity, and dispersal - on the resilience of complex systems, and on the roles that resilience and self-organization play in generating spatial variation. Professor Cumming provides a readable introduction and a first comprehensive synthesis covering the core concepts and applications of spatial resilience to the study of social-ecological systems. The book follows a trajectory from concepts through models, methods, and case study analysis before revisiting the central problems in the further conceptual development of the field. In the process, the author ranges from the movements of lions in northern Zimbabwe to the urban jungles of Europe, and from the collapse of past societies to the social impacts of modern conflict. The many case studies and examples discussed in the book show how the concept of spatial resilience can generate valuable insights into the spatial dynamics of social-ecological systems and contribute to solving some of the most pressing problems of our time. Although it has been written primarily for students, this book will provide fascinating reading for interdisciplinary scientists at all career stages as well as for the interested public. In this engagingly crafted book Graeme Cumming provides a novel, and I believe important, synthesis of spatial aspects of the resilience of coupled ecological and social systems
Current themes and recent advances in modelling species occurrences
Recent years have seen a huge expansion in the range of methods and approaches that are being used to predict species occurrences. This expansion has been accompanied by many improvements in statistical methods, including more accurate ways of comparing models, better null models, methods to cope with autocorrelation, and greater awareness of the importance of scale and prevalence. However, the field still suffers from problems with incorporating temporal variation, overfitted models and poor out-of-sample prediction, confusion between explanation and prediction, simplistic assumptions, and a focus on pattern over process. The greatest advances in recent years have come from integrative studies that have linked species occurrence models with other themes and topics in ecology, such as island biogeography, climate change, disease geography, and invasive species
A modular FPGA-based ultrasonic array system for applications including non-destructive testing
This paper reports work aimed at the development of an ultrasonic imaging system comprising modular, reprogrammable building blocks, or tiles, which can be customised for multiple applications, including and within non-destructive testing (NDT), by the user. The key component is an autonomous module containing the ultrasonic array and all the electronics necessary to operate it. This contrasts with most previous research on system integration which has focused only on the transducer and front-end electronics.<p></p>
In the present work, a 4 4 element 2D piezoelectric array with a 16 mm 16 mm aperture has been produced, with the entire transmission and reception electronics within the same footprint. The proximity of the transducer array and electronics removes the need for cabling, reducing signal degradation due to cross talk and interference. In addition, it avoids the problem of electrical impedance matching of cable between the array elements and the electronics. <p></p>
Pulse-echo insertion loss of 48 dB has been measured from back-wall reflections in 73 mm-thick aluminium without decoding, and results with decoded signals show adequate signal-to-noise ratio (SNR) with 3.3 V excitation at an operating frequency of 1.2 MHz, within the range required for deep penetration in nuclear power plant. <p></p>
Crucially, the ability to construct 2D arrays of any size and shape from generic building blocks represents a departure from almost all previous work in ultrasound, which has traditionally been highly application specific. This may allow ultrasonic NDT to be used in applications for which the investment in customised devices could not previously be justified. <p></p>
CMOS compatible metamaterial absorbers for hyperspectral medium wave infrared imaging and sensing applications
We experimentally demonstrate a CMOS compatible medium wave infrared metal-insulator-metal (MIM) metamaterial absorber structure where for a single dielectric spacer thickness at least 93% absorption is attained for 10 separate bands centred at 3.08, 3.30, 3.53, 3.78, 4.14, 4.40, 4.72, 4.94, 5.33, 5.60 Όm. Previous hyperspectral MIM metamaterial absorber designs required that the thickness of the dielectric spacer layer be adjusted in order to attain selective unity absorption across the band of interest thereby increasing complexity and cost. We show that the absorption characteristics of the hyperspectral metamaterial structures are polarization insensitive and invariant for oblique incident angles up to 25° making them suitable for practical implementation in an imaging system. Finally, we also reveal that under TM illumination and at certain oblique incident angles there is an extremely narrowband Fano resonance (Q < 50) between the MIM absorber mode and the surface plasmon polariton mode that could have applications in hazardous/toxic gas identification and biosensing
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