7 resultados para far-field

em Deakin Research Online - Australia


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This paper investigates and measures the near end and far end crosstalk in the multiconductor transmission line (MTL) mounted on the PCB by varying the parameters which are associated with physical dimension, characteristic of the substrate and the nature of input signal. With the variation of these factors, the coupling inductance and capacitance vary causing crosstalk. By using the method of moment (MoM), the per unit length parameters are calculated for microstrip lines. Subcircuit model is used to investigate the time domain and frequency domain analysis of near field and far field crosstalk. This parametric investigation is very useful for designing high speed interconnectors on PCB substrates. Some experimental results are presented to validate the analytical findings.

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Soft matter deforms in response to imposed external forces. Here we demonstrate how dynamic surface forces are linked to far-field deformations. This offers a new paradigm for determining forces between soft particles in colloidal systems. The particular example we use to illustrate this concept is that of a fluid drop interacting with a solid wall through hydrodynamic drainage flow coupled with repulsive or attractive dissimilar electrical double layer interactions. The force can be deduced from a simple analysis of the drop surface geometry outside the interaction zone.

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The purpose of this study is to design a low-cost planar Archimedean dipole antenna for batteryless transcranial direct current stimulation devices. The antenna parameters including resonance frequency, radiation efficiency, radiation pattern, and gain are simulated using finite difference time domain based electromagnetic simulation software XFdtd. The proposed antenna is simulated with low-cost FR4 PCB substrate of thickness of 1.6 mm. The antenna is designed with half wavelength of resonant frequency and fed with a matching line. The target frequency band is the industrial, scientific and medical (ISM) band of 915 MHz which is in the simulated band width of 31 MHz (903-934MHz). Moreover, since the bio-effect of specific absorption rate by radio frequency electromagnetic wave for power harvesting is an important concern, we try to find out the safety limit. Thus a quantitative analysis of distributions of electric field and power absorption in anatomical human head model by the far field radio frequency energy received by our designed antenna has been presented.

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Disasters, emergencies, incidents, and major incidents - they all come back to the same thing regardless of what they are called. The common denominator is that there is loss of life, injury to people and animals and damage and destruction of property. The management of such events relies on four phases: 1. Prevention 2. Preparation 3. Response 4. Recovery Each of these phases is managed in a different way and often by different teams. Here, concentration has been given to phases 2 and 3, with particular emphasis on phase 3, Response. The words used to describe such events are often related to legislation. The terminology is detailed later. However, whatever the description, whenever prevention is not possible, or fails, then the need is to respond. Response is always better when the responders are prepared. Training is a major part of response preparation and this book is designed to assist those in the health industry who need to be ready when something happens. One of the training packages for responders is the Major Incident Medical Management and Support (MIMMS) Course and this work was designed to supplement the manual prepared by Hodgetts and Macway-Jones(87) in the UK. Included is what the health services responder, who may be sent to an event in which the main concern is trauma, should know. Concentration is on the initial response and does not deal in any detail with hospital reaction, the public health aspects, or the mental health support that provides psychological help to victims and responders, and which are also essential parts of disaster management. People, in times of disaster, have always been quick to offer assistance. It is now well recognised however, that the 'enthusiastic amateur', whilst being a well meaning volunteer, isn't always what is needed. All too often such people have made things worse and have sometimes ended up as victims themselves. There is a place now for volunteers and there probably always will be. The big difference is that these people must be well informed, well trained and well practiced if they are to be effective. Fortunately such people and organisations do exist. Without the work of the St John Ambulance, the State Emergency Service, the Rural Fire Service the Red Cross and the Volunteer Rescue Association, to mention only a few, our response to disasters would be far less effective. There is a strong history of individuals being available to help the community in times of crisis. Mostly these people were volunteers but there has also always been the need for a core of professional support. In the recent past, professional support mechanisms have been developed from lessons learned, particularly to situations that need a rapid and well organised response. As lessons are learned from an analysis of events, philosophy and methods have changed. Our present system is not perfect and perhaps never will be. The need for an 'all-hazards approach' makes detailed planning very difficult and so there will probably always be criticisms about the way an event was handled. Hindsight is a wonderful thing, provided we learn from it. That means that this text is certainly not the 'last word' and revisions as we learn from experience will be inevitable. Because the author works primarily in New South Wales, many of the explanations and examples are specific to that state. In Australia disaster response is a State, rather than a Commonwealth, responsibility and consequently, and inevitably, there are differences in management between the states and territories within Australia. With the influence of Emergency Management Australia, these differences are being reduced. This means that across state and territory boundaries, assistance is common and interstate teams can be deployed and assimilated into the response rapidly, safely, effectively and with minimum explanation. This text sets out to increase the understanding of what is required, what is in place and how the processes of response are managed. By way of introduction and background, examples are given of those situations that have occurred, or could happen. Man Made Disasters has been divided into two distinct sections. Those which are related to structures or transport and those related directly to people. The first section, Chapter 3, includes: • Transport accidents involving land, rail, sea or air vehicles. • Collapse of buildings for reasons other than earthquakes or storms. • Industrial accidents, including the release of hazardous substances and nuclear events. A second section dealing with the consequences of the direct actions of people is separated as Chapter 4, entitled 'People Disasters'. Included are: • Crowd incidents involving sports and entertainment venues. • Terrorism From Chapter 4 on, the emphasis is on the Response phase and deals with organisation and response techniques in detail. Finally there is a section on terminology and abbreviations. An appendix details a typical disaster pack content. War, the greatest of all man made disasters is not considered in this text.

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Noncovalent recognition between peptides and inorganic materials is an established phenomenon. Key to exploiting these interactions in a wide range of materials self-assembly applications would be to harness the facet-selective control of peptide binding onto these materials. Fundamental understanding of what drives facet-selectivity in peptide binding is developing, but as yet is not sufficient to enable design of predictable facet-specific sequences. Computational simulation of the aqueous peptide-gold interface, commonly used to understand the mechanisms driving adsorption at an atomic level, has thus far neglected the role that surface reconstruction might play in facet specificity. Here the polarizable GolP-CHARMM suite of force fields is extended to include the reconstructed Au(100) surface. The force field, compatible with the bio-organic force field CHARMM, is parametrized using first-principles data. Our extended force field is tailored to reproduce the heterogeneity of weak chemisorbing N and S species to specific locations in the Au(100)(5 × 1) surface identified from the first-principles calculations. We apply our new model to predict and compare the three-dimensional structure of liquid water at Au(111), Au(100)(1 × 1), and Au(100)(5 × 1) interfaces. Using molecular dynamics simulations, we predict an increased likelihood for water-mediated peptide adsorption at the aqueous-Au(100)(1 × 1) interface compared with the Au(100)(5 × 1) interface. Therefore, our findings suggest that peptide binding can discriminate between the native and reconstructed Au(100) interfaces and that the role of reconstruction on binding at the Au(100) interface should not be neglected. © 2013 American Chemical Society.

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Aims/hypothesis
Impaired central vision has been shown to predict diabetic peripheral neuropathy (DPN). Several studies have demonstrated diffuse retinal neurodegenerative changes in diabetic patients prior to retinopathy development, raising the prospect that non-central vision may also be compromised by primary neural damage. We hypothesise that type 2 diabetic patients with DPN exhibit visual sensitivity loss in a distinctive pattern across the visual field, compared with a control group of type 2 diabetic patients without DPN.

Methods
Increment light sensitivity was measured by standard perimetry in the central 30° of visual field for two age-matched groups of type 2 diabetic patients, with and without neuropathy (n = 40/30). Neuropathy status was assigned using the neuropathy disability score. Mean visual sensitivity values were calculated globally, for each quadrant and for three eccentricities (0–10°, 11–20° and 21–30°). Data were analysed using a generalised additive mixed model (GAMM).

Results
Global and quadrant between-group visual sensitivity mean differences were marginally but consistently lower (by about 1 dB) in the neuropathy cohort compared with controls. Between-group mean differences increased from 0.36 to 1.81 dB with increasing eccentricity. GAMM analysis, after adjustment for age, showed these differences to be significant beyond 15° eccentricity and monotonically increasing. Retinopathy levels and disease duration were not significant factors within the model (p = 0.90).

Conclusions/interpretation
Visual sensitivity reduces disproportionately with increasing eccentricity in type 2 diabetic patients with peripheral neuropathy. This sensitivity reduction within the central 30° of visual field may be indicative of more consequential loss in the far periphery.