First results from the faint object camera - High-resolution imaging of the Pluto-Charon system

1991 ◽  
Vol 374 ◽  
pp. L65 ◽  
Author(s):  
R. Albrecht ◽  
C. Barbieri ◽  
J. C. Blades ◽  
A. Boksenberg ◽  
P. Crane ◽  
...  
2020 ◽  
Author(s):  
Anne Obermann ◽  
Pilar Sánchez-Pastor ◽  
Alejandro Duran ◽  
Tobias Diehl ◽  
Vala Hjörleifsdóttir ◽  
...  

<p>For the future development of deep geothermal energy exploitation in Europe, large magnitude induced seismic events are an obstacle. On the other hand, the analysis of induced microseismicity allows to obtain the spatial distribution of fractures within the reservoir, which can help, not only to identify active faults that may trigger large induced seismic events, but also to optimize hydraulic stimulation operations and to locate the regions with higher permeability, enhancing energy production. The project COSEISMIQ (COntrol SEISmicity and Manage Induced) integrates seismic monitoring and imaging techniques, geomechanical models and risk analysis methods with the ultimate goal of implementing innovative tools for the management of the risks posed by induced seismicity and demonstrate their usefulness in a commercial scale application in Iceland.</p><p>Our demonstration site is the Hengill region in Iceland. The Hengill volcanic complex is located in SW Iceland on the plate boundary between the North American and Eurasian plates. In this region, the two largest geothermal power plants of Iceland are currently in operation, the Nesjavellir (120MW electricity) and the Hellisheidi (300MW electricity) power stations. In October 2018, we densified the permanent seismic network run by ISOR and IMO in this area (14 stations) with 23 broadband seismic stations.</p><p>We present the project and show first results from high resolution imaging of the shallow crust with ambient seismic noise, as well as first results from the relocated seismic events. The ambient noise imaging highlights an area of low seismic velocity close to the Þingvallavatn Lake, characteristic for the presence of supercritical fluids. The main geothermal production area is located as well in a low velocity zone that reaches 200 meters depth below Hellisheidi and around 700 meters below Nesjavellir.</p><p> </p>


1994 ◽  
Vol 435 ◽  
pp. L75 ◽  
Author(s):  
R. Albrecht ◽  
C. Barbieri ◽  
H.-M. Adorf ◽  
G. Corrain ◽  
A. Gemmo ◽  
...  

1991 ◽  
Vol 253 (1) ◽  
pp. 21P-24P ◽  
Author(s):  
N. R. Tanvir ◽  
T. Shanks ◽  
J. V. Major ◽  
A. P. Doel ◽  
C. N. Dunlop ◽  
...  

Icarus ◽  
1998 ◽  
Vol 135 (1) ◽  
pp. 276-302 ◽  
Author(s):  
Robert T. Pappalardo ◽  
James W. Head ◽  
Geoffrey C. Collins ◽  
Randolph L. Kirk ◽  
Gerhard Neukum ◽  
...  

1991 ◽  
Vol 9 (1) ◽  
pp. 162-163 ◽  
Author(s):  
J. G. Robertson ◽  
T. R. Bedding ◽  
R. G. Marson ◽  
P. R. Gillingham ◽  
R. H. Frater ◽  
...  

AbstractWe have successfully demonstrated optical aperture synthesis at the 4-m Anglo-Australian Telescope. By using a multi-hole mask over the (re-imaged) primary mirror and recording the resulting fringe patterns with high time resolution, diffraction-limited images of sufficiently bright objects can be reconstructed. The data processing uses closure phases to overcome the effects of atmospheric turbulence. We show an image of the double star η Oph, with component separation 0″.45.


2010 ◽  
Author(s):  
Michael J. Nasse ◽  
Eric Mattson ◽  
Carol Hirschmugl ◽  
Adriana Predoi-Cross ◽  
Brant E. Billinghurst

Author(s):  
J.M. Cowley

By extrapolation of past experience, it would seem that the future of ultra-high resolution electron microscopy rests with the advances of electron optical engineering that are improving the instrumental stability of high voltage microscopes to achieve the theoretical resolutions of 1Å or better at 1MeV or higher energies. While these high voltage instruments will undoubtedly produce valuable results on chosen specimens, their general applicability has been questioned on the basis of the excessive radiation damage effects which may significantly modify the detailed structures of crystal defects within even the most radiation resistant materials in a period of a few seconds. Other considerations such as those of cost and convenience of use add to the inducement to consider seriously the possibilities for alternative approaches to the achievement of comparable resolutions.


Author(s):  
Max T. Otten ◽  
Wim M.J. Coene

High-resolution imaging with a LaB6 instrument is limited by the spatial and temporal coherence, with little contrast remaining beyond the point resolution. A Field Emission Gun (FEG) reduces the incidence angle by a factor 5 to 10 and the energy spread by 2 to 3. Since the incidence angle is the dominant limitation for LaB6 the FEG provides a major improvement in contrast transfer, reducing the information limit to roughly one half of the point resolution. The strong improvement, predicted from high-resolution theory, can be seen readily in diffractograms (Fig. 1) and high-resolution images (Fig. 2). Even if the information in the image is limited deliberately to the point resolution by using an objective aperture, the improved contrast transfer close to the point resolution (Fig. 1) is already worthwhile.


Author(s):  
Xiao Zhang

Electron holography has recently been available to modern electron microscopy labs with the development of field emission electron microscopes. The unique advantage of recording both amplitude and phase of the object wave makes electron holography a effective tool to study electron optical phase objects. The visibility of the phase shifts of the object wave makes it possible to directly image the distributions of an electric or a magnetic field at high resolution. This work presents preliminary results of first high resolution imaging of ferroelectric domain walls by electron holography in BaTiO3 and quantitative measurements of electrostatic field distribution across domain walls.


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