594 research outputs found
The design and evaluation of a sonically enhanced tool palette
This paper describes an experiment to investigate the effectiveness of adding sound to tool palettes. Palettes have usability problems because users need to see the information they present, but they are often outside the area of visual focus. We used nonspeech sounds called earcons to indicate the current tool and when tool changes occurred so that users could tell what tool they were in wherever they were looking. Results showed a significant reduction in the number of tasks performed with the wrong tool. Therefore, users knew what the current tool was and did not try to perform tasks with the wrong one. All of this was not at the expense of making the tool palettes any more annoying to use
Deposit Formation in the Holes of Diesel Injector Nozzles: A Critical Review
Current developments in fuels and emissions regulations are resulting in increasingly severe operating environment for the injection system. Formation of deposits within the holes of the injector nozzle or on the outside of the injector tip may have an adverse effect on overall system performance. This paper provides a critical review of the current understanding of the main factors affecting deposit formation. Two main types of engine test cycles, which attempt to simulate field conditions, are described in the literature. The first type involves cycling between high and low load. The second involves steady state operation at constant speed either at medium or high load. A number of influences on the creation of deposits are identified. This includes fouling through thermal condensation and cracking reactions at nozzle temperatures of around 300°C. Also the design of the injector holes is an influence, because it can influence cavitation. The implosion of cavitation bubbles is believed to limit nozzle deposits. Field and laboratory tests showed that small amounts (around 1ppm) of zinc tend to increase the formation of deposits and are therefore another influence. But it is not clear whether zinc acts catalytically to accelerate deposit formation or if it becomes part of the solid deposits. Bio-diesel has been observed to lead to higher deposit formation in the injector nozzle. The chemical and physical processes that lead to deposit formation are not known or well understood, due to their complexity. A physical mechanism put forward focuses on the role of the residual fuel that remains in the nozzle holes after the end of the injection process. © 2008 SAE International
Sonically-enhanced widgets: comments on Brewster and Clarke, ICAD 1997
This paper presents a review of the research surrounding the paper “The Design and Evaluation of a Sonically Enhanced Tool Palette” by Brewster and Clarke from ICAD 1997. A historical perspective is given followed by a discussion of how this work has fed into current developments in the area
Morphodynamics of nearshore rhythmic sandbars in a mixed-energy environment (SW France): I. Mapping beach changes using visible satellite imagery
This paper presents a new method to analyze the morphology and migration of shallow water sandbanks based on the retrieval of maps from high-resolution Spot satellite imagery. This approach was applied to the study of intertidal ridge and runnel systems and subtidal crescents that border the southwest coast of France. Maps were obtained from 16 Spot images recorded between 1986 and 2000. Ridge and runnel shapes, with regard to a reference level, were delineated using a watercolor reflectance code parameterized and validated with field data. Crescent plan shapes, which appear on the images due to water transparency or breaking-induced foam, were directly extracted. The spatial maps show that, in conformity with field surveys, the mean alongshore spacing of intertidal systems and crescents range from 370 ± 146 m (variability is indicated by standard deviation) to 462 ± 188 m, and from 579 ± 200 to 818 ± 214 m, respectively. Several couples of images also show that ridge and runnel systems and crescents move in the longshore drift direction (southward) by about 2.4–3.1 and 1 m day−1, respectively. Alongshore migration rates of intertidal systems are confirmed by field surveys, whilst crescent dynamics cannot be validated because there is no in situ data available. To complete these measurements, an analysis of the influence of wave climate on both the shape and movements of these rhythmic sedimentary patterns is proposed in a companion paper
Full potential LAPW calculation of electron momentum density and related properties of Li
Electron momentum density and Compton profiles in Lithium along , and directions are calculated using Full-Potential Linear
Augmented Plane Wave basis within generalized gradient approximation. The
profiles have been corrected for correlations with Lam-Platzman formulation
using self-consistent charge density. The first and second derivatives of
Compton profiles are studied to investigate the Fermi surface breaks. Decent
agreement is observed between recent experimental and our calculated values.
Our values for the derivatives are found to be in better agreement with
experiments than earlier theoretical results. Two-photon momentum density and
one- and two-dimensional angular correlation of positron annihilation radiation
are also calculated within the same formalism and including the
electron-positron enhancement factor.Comment: 11 pages, 7 figures TO appear in Physical Review
3D time series analysis of cell shape using Laplacian approaches
Background:
Fundamental cellular processes such as cell movement, division or food uptake critically depend on cells being able to change shape. Fast acquisition of three-dimensional image time series has now become possible, but we lack efficient tools for analysing shape deformations in order to understand the real three-dimensional nature of shape changes.
Results:
We present a framework for 3D+time cell shape analysis. The main contribution is three-fold: First, we develop a fast, automatic random walker method for cell segmentation. Second, a novel topology fixing method is proposed to fix segmented binary volumes without spherical topology. Third, we show that algorithms used for each individual step of the analysis pipeline (cell segmentation, topology fixing, spherical parameterization, and shape representation) are closely related to the Laplacian operator. The framework is applied to the shape analysis of neutrophil cells.
Conclusions:
The method we propose for cell segmentation is faster than the traditional random walker method or the level set method, and performs better on 3D time-series of neutrophil cells, which are comparatively noisy as stacks have to be acquired fast enough to account for cell motion. Our method for topology fixing outperforms the tools provided by SPHARM-MAT and SPHARM-PDM in terms of their successful fixing rates. The different tasks in the presented pipeline for 3D+time shape analysis of cells can be solved using Laplacian approaches, opening the possibility of eventually combining individual steps in order to speed up computations
The Effects of Alfven Waves and Radiation Pressure in Dust Winds of Late-type Stars
In the present study, we analyze the effects of a flux of Alfven waves acting
together with radiation pressure on grains as an acceleration mechanism of the
wind of late-type stars. In the wind model we simulate the presence of grains
through a strong damping of the waves, we used a non-isothermal profile for
temperature, coherent with grain formation theories. We examine the changes in
the velocity profile of the wind and we show that if the grains are created in
the region 1.1 < r/r_0 < 2.0 their presence will affect the mass loss and
terminal velocity. The model is applied to a K5 supergiant star and for
Betelgeuse (alpha Ori).Comment: 6 pages, 3 figures, accepted in ApJ (Sep, 2002
Atmospheric aerosols at the Pierre Auger Observatory and environmental implications
The Pierre Auger Observatory detects the highest energy cosmic rays.
Calorimetric measurements of extensive air showers induced by cosmic rays are
performed with a fluorescence detector. Thus, one of the main challenges is the
atmospheric monitoring, especially for aerosols in suspension in the
atmosphere. Several methods are described which have been developed to measure
the aerosol optical depth profile and aerosol phase function, using lasers and
other light sources as recorded by the fluorescence detector. The origin of
atmospheric aerosols traveling through the Auger site is also presented,
highlighting the effect of surrounding areas to atmospheric properties. In the
aim to extend the Pierre Auger Observatory to an atmospheric research platform,
a discussion about a collaborative project is presented.Comment: Regular Article, 16 pages, 12 figure
Production, characterization, and antigen specificity of recombinant 62-71-3, a candidate monoclonal antibody for rabies prophylaxis in humans
Rabies kills many people throughout the developing world every year. The murine monoclonal antibody (mAb) 62-71-3 was recently identified for its potential application in rabies postexposure prophylaxis (PEP). The purpose here was to establish a plant-based production system for a chimeric mouse-human version of mAb 62-71-3, to characterize the recombinant antibody and investigate at a molecular level its interaction with rabies virus glycoprotein. Chimeric 62-71-3 was successfully expressed in Nicotiana benthamiana. Glycosylation was analyzed by mass spectroscopy; functionality was confirmed by antigen ELISA, as well as rabies and pseudotype virus neutralization. Epitope characterization was performed using pseudotype virus expressing mutagenized rabies glycoproteins. Purified mAb demonstrated potent viral neutralization at 500 IU/mg. A critical role for antigenic site I of the glycoprotein, as well as for two specific amino acid residues (K226 and G229) within site I, was identified with regard to mAb 62-71-3 neutralization. Pseudotype viruses expressing glycoprotein from lyssaviruses known not to be neutralized by this antibody were the controls. The results provide the molecular rationale for developing 62-71-3 mAb for rabies PEP; they also establish the basis for developing an inexpensive plant-based antibody product to benefit low-income families in developing countries.—Both, L., van Dolleweerd, C., Wright, E., Banyard, A. C., Bulmer-Thomas, B., Selden, D., Altmann, F., Fooks, A. R., Ma, J. K.-C. Production, characterization, and antigen specificity of recombinant 62-71-3, a candidate monoclonal antibody for rabies prophylaxis in humans
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