scholarly journals The earthquake that shook central Sjælland, Denmark, November 6, 2001

2008 ◽  
Vol 56 ◽  
pp. 26-37
Author(s):  
T. B. Larsen ◽  
V. Orozova Bekkevold
Keyword(s):  
Quaternary Sediments ◽  
Large Area ◽  
Small Earthquake ◽  
Human Subjectivity ◽  
Richter Scale ◽  
Local Geology ◽  
Felt Area ◽  
Determining Factor

Earthquakes on Sjælland are in general small and seldom felt. The largest earthquakes in the Danish region occur in Skagerrak and Kattegat, and they are felt in NW Jylland (Thy) and in North Sjælland on average several years apart. A small earthquake measuring just 2.8 on the Richter Scale was felt and heard over a surprisingly large area of Sjælland, Denmark on November 6, 2001. The earthquake caused people to abruptly leave their houses near the epicenter, and minor damage to several buildings was observed. The felt area is oriented strongly asymmetrically with respect to the epicenter, but it correlates well with the local geology. Specifically the shaking was felt in a region where the depth to the Top Chalk surface is small, and the thickness of the Quaternary sediments is less than 50 m. In 1869 an earthquake was felt strongly in the exact same area, and contours separating the felt area from the area where nothing was felt coincide almost exactly for the two earthquakes. This supports that geology and not human subjectivity is the determining factor in delineating the felt area for this earthquake.

scholarly journals Flare puffs as a cause of type III radio bursts

1959 ◽  
Vol 9 ◽  
pp. 214-214
Author(s):  
R. G. Giovanelli
Keyword(s):  
Strong Association ◽  
The Other ◽  
Radio Bursts ◽  
Large Area ◽  
Type Iii ◽  
Apparent Area ◽  
Other Hand ◽  
Determining Factor

It has been well established that a strong association exists between flares and type III bursts: Loughhead, Roberts, and McCabe [1] showed that 60 to 70 per cent of type III bursts occurred during the lifetimes of flares or microflares of apparent area exceeding about 20 × 10–6 solar hemispheres. On the other hand, only about 22 per cent of all such flares are associated with bursts. This low figure indicates that there are differences of degree or type between various flares, but the large area range involved shows that flare size alone is not the determining factor.

Chapter 8 Northwestern Spitsbergen

1997 ◽  
Vol 17 (1) ◽  
pp. 132-153
Author(s):  
W. Brian Harland ◽  
Paul A. Doubled Ay
Keyword(s):  
Fault Zone ◽  
Central Basin ◽  
Central Province ◽  
Quaternary Sediments ◽  
The South ◽  
Large Area ◽  
Southern Boundary ◽  
James I ◽  
Western Sector ◽  
The North

Northwestern Spitsbergen is bounded by Billefjorden and Wijde-fjorden in the east and by the coastline in the north and west round to the southwest by Kongsfjorden (Fig. 8.1). The southern boundary overlaps with the Central Basin (Chapter 4) and central western sector of Spitsbergen (Chapter 9) along Kongsfjorden and Sveabreen. At this boundary Devonian and older rocks are uncon-formably overlain, and finally obscured to the south, by the cover of Carboniferous through Paleogene strata. This sector contains Andree Land, Albert I Land, Haakon VII Land, James I Land and northern Dickson Land. It is deeply penetrated by fjords and largely covered by ice.Apart from Quaternary sediments and volcanics, Cenozoic plateau lavas and the overlying platform sequence (Carboniferous through Paleogene) to the south, the main consideration here is with Devonian sediments, mid-Paleozoic migmatites and granites, and Precambrian metasediments.The Northwestern sector is bounded and divided by faults. The eastern boundary is delineated by the Billefjorden Fault Zone (BFZ) and the southwestern boundary is the postulated Kongs-fjorden-Hansbreen Fault Zone (KHFZ). These faults separate the Central Province respectively from the Eastern and Western provinces. Two main N-S oriented faults divide the sector into three terranes: the Raudfjorden Fault (RFF), and the Breibogen Fault (BBF) (Fig. 8.1) as noted by Holtedahl (1914). The three terranes are introduced below. (1) The Andree Land-Dickson Land Terrane is a large area of Devonian strata bounded by the Breibogen Fault Zone and the Billefjorden Fault Zone. (2) The Biskayerfonna-Holtedahlfonna Terrane is a N-S belt bounded to the

A note on the Charleston earthquake*

1945 ◽  
Vol 35 (2) ◽  
pp. 49-56
Author(s):  
Harry O. Wood
Keyword(s):  
Energy Intensity ◽  
Earthquake Magnitude ◽  
Depth Of Focus ◽  
Large Area ◽  
Richter Scale

Abstract Data of observation presented in Dutton's report upon the Charleston earthquake are tested with formulas extracted from the paper by Gutenberg and Richter on “Earthquake Magnitude, Energy, Intensity, and Acceleration,” with the resulting suggestions that the depth of focus may have been near 40 kilometers (25 miles) and the shock magnitude a little less than 8 on the Richter scale. Definite conclusions cannot be reached with the inadequate data now available, but this would explain the large area of perceptibility of the Charleston shock as compared, for example, with those of earthquakes in California.

Convergent Beam Electron Diffraction

1978 ◽  
Vol 36 (3) ◽  
pp. 304-315
Author(s):  
G. Lehmpfuhl
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Crystal Surface ◽  
Diffraction Spot ◽  
Crystal Thickness ◽  
Large Area ◽  
Electron Microscopic ◽  
Additional Information ◽  
Microscopic Investigations

Introduction In electron microscopic investigations of crystalline specimens the direct observation of the electron diffraction pattern gives additional information about the specimen. The quality of this information depends on the quality of the crystals or the crystal area contributing to the diffraction pattern. By selected area diffraction in a conventional electron microscope, specimen areas as small as 1 µ in diameter can be investigated. It is well known that crystal areas of that size which must be thin enough (in the order of 1000 Å) for electron microscopic investigations are normally somewhat distorted by bending, or they are not homogeneous. Furthermore, the crystal surface is not well defined over such a large area. These are facts which cause reduction of information in the diffraction pattern. The intensity of a diffraction spot, for example, depends on the crystal thickness. If the thickness is not uniform over the investigated area, one observes an averaged intensity, so that the intensity distribution in the diffraction pattern cannot be used for an analysis unless additional information is available.

TEM Study of a Tilt Boundary in Hot-Pressed Silicon

1981 ◽  
Vol 39 ◽  
pp. 160-161
Author(s):  
C. B. Carter ◽  
J. Rose ◽  
D. G. Ast
Keyword(s):  
Electron Diffraction ◽  
Imaging Technique ◽  
Interface Structure ◽  
Large Area ◽  
Weak Beam ◽  
Lattice Fringe ◽  
Electron Diffraction Technique ◽  
Tilt Boundaries ◽  
Beam Technique ◽  
Twist Boundaries

The hot-pressing technique which has been successfully used to manufacture twist boundaries in silicon has now been used to form tilt boundaries in this material. In the present study, weak-beam imaging, lattice-fringe imaging and electron diffraction techniques have been combined to identify different features of the interface structure. The weak-beam technique gives an overall picture of the geometry of the boundary and in particular allows steps in the plane of the boundary which are normal to the dislocation lines to be identified. It also allows pockets of amorphous SiO2 remaining in the interface to be recognized. The lattice-fringe imaging technique allows the boundary plane parallel to the dislocation to be identified. Finally the electron diffraction technique allows the periodic structure of the boundary to be evaluated over a large area - this is particularly valuable when the dislocations are closely spaced - and can also provide information on the structural width of the interface.

P20 phosphor on polyimide as a large area high-resolution transmission screen for slow scan CCD systems

1995 ◽  
Vol 53 ◽  
pp. 20-21
Author(s):  
C. C. Ahn ◽  
S. Karnes ◽  
M. Lvovsky ◽  
C. M. Garland ◽  
H. A. Atwater ◽  
...  
Keyword(s):  
Mechanical Stability ◽  
High Energy ◽  
Practical Implementation ◽  
Line Pair ◽  
Modulation Transfer ◽  
Large Area ◽  
Ccd Imaging ◽  
Transmission Electron ◽  
The One ◽  
Beam Broadening

The bane of CCD imaging systems for transmission electron microscopy at intermediate and high voltages has been their relatively poor modulation transfer function (MTF), or line pair resolution. The problem originates primarily with the phosphor screen. On the one hand, screens should be thick so that as many incident electrons as possible are converted to photons, yielding a high detective quantum efficiency(DQE). The MTF diminishes as a function of scintillator thickness however, and to some extent as a function of fluorescence within the scintillator substrates. Fan has noted that the use of a thin layer of phosphor beneath a self supporting 2μ, thick Al substrate might provide the most appropriate compromise for high DQE and MTF in transmission electron microcscopes which operate at higher voltages. Monte Carlo simulations of high energy electron trajectories reveal that only little beam broadening occurs within this thickness of Al film. Consequently, the MTF is limited predominantly by broadening within the thin phosphor underlayer. There are difficulties however, in the practical implementation of this design, associated mostly with the mechanical stability of the Al support film.

Study of Tip-Surface Interactions in Scanning Tunneling Microscopy (STM) by Reflection Electron Microscopy (REM)

1990 ◽  
Vol 48 (1) ◽  
pp. 320-321
Author(s):  
W. Lo ◽  
J.C.H. Spence ◽  
M. Kuwabara
Keyword(s):  
High Resolution ◽  
Elastic Strain ◽  
Tunneling Current ◽  
Surface Damage ◽  
Surface Interactions ◽  
Graphite Surface ◽  
Scanning Tunneling ◽  
Large Area ◽  
Tunneling Microscopy ◽  
High Resolution Tem

Work on the integration of STM with REM has demonstrated the usefulness of this combination. The STM has been designed to replace the side entry holder of a commercial Philips 400T TEM. It allows simultaneous REM imaging of the tip/sample region of the STM (see fig. 1). The REM technique offers nigh sensitivity to strain (<10−4) through diffraction contrast and high resolution (<lnm) along the unforeshortened direction. It is an ideal technique to use for studying tip/surface interactions in STM.The elastic strain associated with tunnelling was first imaged on cleaved, highly doped (S doped, 5 × 1018cm-3) InP(110). The tip and surface damage observed provided strong evidence that the strain was caused by tip/surface contact, most likely through an insulating adsorbate layer. This is consistent with the picture that tunnelling in air, liquid or ordinary vacuum (such as in a TEM) occurs through a layer of contamination. The tip, under servo control, must compress the insulating contamination layer in order to get close enough to the sample to tunnel. The contaminant thereby transmits the stress to the sample. Elastic strain while tunnelling from graphite has been detected by others, but never directly imaged before. Recent results using the STM/REM combination has yielded the first direct evidence of strain while tunnelling from graphite. Figure 2 shows a graphite surface elastically strained by the STM tip while tunnelling (It=3nA, Vtip=−20mV). Video images of other graphite surfaces show a reversible strain feature following the tip as it is scanned. The elastic strain field is sometimes seen to extend hundreds of nanometers from the tip. Also commonly observed while tunnelling from graphite is an increase in the RHEED intensity of the scanned region (see fig.3). Debris is seen on the tip and along the left edges of the brightened scan region of figure 4, suggesting that tip abrasion of the surface has occurred. High resolution TEM images of other tips show what appear to be attached graphite flakes. The removal of contamination, possibly along with the top few layers of graphite, seems a likely explanation for the observed increase in RHEED reflectivity. These results are not inconsistent with the “sliding planes” model of tunnelling on graphite“. Here, it was proposed that the force due to the tunnelling probe acts over a large area, causing shear of the graphite planes when the tip is scanned. The tunneling current is then modulated as the planes of graphite slide in and out of registry. The possiblity of true vacuum tunnelling from the cleaned graphite surface has not been ruled out. STM work function measurements are needed to test this.

Illumination from Large Area Light Sources—II

1914 ◽  
Vol 77 (1988supp) ◽  
pp. 82-83
Author(s):  
Herbert E. Ives
Keyword(s):  
Light Sources ◽  
Large Area

Computer simulation study about the dependence of amorphous silicon photonic waveguides efficiency on the material quality

2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira
Keyword(s):  
Amorphous Silicon ◽  
High Throughput Screening ◽  
Simulation Analysis ◽  
Low Cost ◽  
Deposition Process ◽  
Large Area ◽  
Sidewall Roughness ◽  
Sensing Applications ◽  
Fabrication Defects ◽  
The Impact

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.

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