scholarly journals RELIEF DEVELOPMENT OF THE BABIA GÓRA MASSIF, WESTERN CARPATHIAN MOUNTAINS

2014 ◽  
Vol 33 (1) ◽  
pp. 89-106
Author(s):  
Adam Łajczak
Keyword(s):  
Cross Section ◽  
Thick Layer ◽  
Northern Slope ◽  
Large Area ◽  
Carpathian Mountains ◽  
Aerial Photos ◽  
Tectonic Faults ◽  
Geological Maps ◽  
Landform Development ◽  
Steep Slopes

Abstract The paper discusses structural considerations relating to landform development on Mt. Babia Góra (1,725 m a.s.l.), the highest massif in the flysch section of the Western Carpathian Mountains. The Babia Góra massif consists of folded Palaeogene-age sediments, including resistant Magura sandstone and less resistant sub-Magura layers, with numerous tectonic faults. The area has inverse-type geomorphology. The monoclinal ridge of the massif itself consists of the resistant Magura sandstone dipping southwards. Since the Miocene, the development of the massif’s relief has involved a number of processes, including: tectonic uplifting, removal of a thick layer of rocks, exposure of sub-Magura layers over a large area, the staged development of valleys dissecting the pediments surrounding the ever higher ridge, and slope retreat due to deep landsliding. Axes of linear terrain forms, escarpments of landslide scars and of headwater areas follow two main intersecting fracture lines present within the massif. Large quantities of colluvial material are transported away from the massif along these lines. The development of the land relief has led to the elongation of slopes as local elevation differences increased. Landsliding has developed in an uphill direction, which means that the youngest relief is observed on the highest sections of steep slopes. The development of the massif’s northern slope, which has formed a high and precipitous cuesta, began to accelerate only after a nearly complete exposure of the sub-Magura layers at its foot. Following this exposure the profile of the massif’s N-S cross-section has begun to become asymmetrical. With time, the degree of general remodelling of the massif has tended to decrease. As a result, the geomorphological contrast between the northern and southern sides of the massif has become well established. The description of the probable development of the Babia Góra relief is based on the author’s fieldwork, an analysis of geological maps and aerial photos, and on literature.

Large Area DPB Free (111) β-SiC Thick Layer Grown on (0001) α-SiC Nominal Surfaces by the CF-PVT Method

2005 ◽  
Vol 483-485 ◽  
pp. 225-228 ◽  
Author(s):  
Didier Chaussende ◽  
Laurence Latu-Romain ◽  
Laurent Auvray ◽  
M. Ucar ◽  
Michel Pons ◽  
...  
Keyword(s):  
Growth Rate ◽  
Optical Microscopy ◽  
Cross Section ◽  
Thick Layer ◽  
Vapour Transport ◽  
Large Area ◽  
Continuous Feed ◽  
Heating Up ◽  
Cross Section Geometry ◽  
Selection Of

Thick (111) oriented β-SiC layers have been grown by hetero-epitaxy on a (0001) a-SiC substrate with the Continuous Feed-Physical Vapour Transport (CF-PVT) method. The growth rate was 68 µm/h at a pressure of 2 torr and a temperature of 1950°C. The nucleation step of the β-SiC layer during the heating up of the process was studied in order to manage first the a to b heteropolytypic transition and second the selection of the b-SiC orientation. With a adapted seeding stage, we grew a 0.4mm thick layer almost free of Double Positioning Boundaries on a 30mm diameter sample. First observations of the layer by cross-polarised optical Microscopy are presented both in planar view and in cross section geometry.

scholarly journals Using GIS to detect neotectonics in the Vsetínské vrchy Mountains and in their surroundings

Geografie ◽  
2003 ◽  
Vol 108 (2) ◽  
pp. 101-114
Author(s):  
Michal Bíl
Keyword(s):  
Czech Republic ◽  
Numerical Analysis ◽  
Large Scale ◽  
Dynamic Equilibrium ◽  
Large Area ◽  
The Czech Republic ◽  
Geological Maps ◽  
Bedrock Geology ◽  
Steep Slopes ◽  
Topographic Relief

This paper discusses the advantages of GIS and numerical analysis in neotectonic studies. An accurate DEM is important for numerous geomorphic and hydrologic applications, particularly over large areas. The method is illustrated on the DEM of the Vsetínské vrchy Mountains, a 367 square km large area in the east of the Czech Republic. Comparing geological maps with large-scale morphometry shows a relationship between the rock resistance and topography. On average, higher mean elevations and steep slopes correlate well with regions of hard bedrock geology. The results together with new geological and geophysical findings show that the evolution of this part of the Outer Western Carpathian topography was proceeding continually. There is no reason to assume the presence of any periods of tectonic standstill here. The topographic relief probably has experienced the state of dynamic equilibrium.

scholarly journals A possible radio signal of annihilating dark matter in the Abell 4038 cluster

2019 ◽  
Vol 495 (1) ◽  
pp. L124-L128 ◽  
Author(s):  
Man Ho Chan ◽  
Chak Man Lee
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Radio Signal ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
Annihilation Cross Section ◽  
Radio Continuum ◽  
Test Statistic ◽  
Large Area ◽  
Dark Matter Annihilation

ABSTRACT In the past decade, some telescopes [e.g. Fermi-Large Area Telescope (LAT), Alpha Magnetic Spectrometer(AMS), and Dark Matter Particle Explorer(DAMPE)] were launched to detect the signals of annihilating dark matter in our Galaxy. Although some excess of gamma-rays, antiprotons, and electrons/positrons have been reported and claimed as dark matter signals, the uncertainties of Galactic pulsars’ contributions are still too large to confirm the claims. In this Letter, we report a possible radio signal of annihilating dark matter manifested in the archival radio continuum spectral data of the Abell 4038 cluster. By assuming the thermal annihilation cross-section and comparing the dark matter annihilation model with the null hypothesis (cosmic ray emission without dark matter annihilation), we get very large test statistic values >45 for four popular annihilation channels, which correspond to more than 6.5σ statistical preference. This provides a very strong evidence for the existence of annihilating dark matter. In particular, our results also support the recent claims of dark matter mass m ≈ 30–50 GeV annihilating via the bb̄ quark channel with the thermal annihilation cross-section.

scholarly journals Upgrade of existing algorithms for creating contour lines on topographic maps of the karst surface

2020 ◽  
Vol 2 ◽  
pp. 1-2
Author(s):  
Neža Ema Komel ◽  
Klemen Kozmus Trajkovski ◽  
Dušan Petrovič
Keyword(s):  
Topographic Maps ◽  
Topographic Map ◽  
Basic Algorithm ◽  
Commercial Software ◽  
Karst Terrain ◽  
Aerial Photos ◽  
Contour Lines ◽  
Elevation Model ◽  
Future Work ◽  
Steep Slopes

Abstract. Today, many software tools enable the production of contour lines from relief models, but the results of modelling complex karst relief are often inadequate. Reasons for this may be limited quality and resolution of relief models, limitations of algorithms for calculating contours, or limitations of algorithms for smoothing and displaying additional symbols that further describe relief, such as slope lines, steep slopes and smaller objects that cannot be effectively displayed with contours, etc.We will present research in the field of improving existing algorithms in rugged karst terrain. As a target result, the presentation of relief on the existing national topographic maps in Slovenia, which were made by manual photogrammetric survey of aerial photos stereo pairs, were used. Slovenian elevation model DMR1 (1 m density) is used as a source for the creation of contour lines in various commercial software packages, and by comparing the results with a relief presentation on a topographic map, we selected the most appropriate basic algorithm. This one is further upgraded mainly by enabling automatic selection of auxiliary contour lines in the area, presentation of individual smaller relief objects with appropriate point or linear symbols, addition of slope lines on contours and indications in the middle of depressions and displacement of contour lines in order to better depict the terrain morphology.The results were tested in four different areas in Slovenia. Figure 1 shows the contour lines for a testing area near village Opatje Selo near Slovenia-Italy border, which were made by the best commercial software. The results of the algorithm are shown in Figure 2. The comparison between the results of the algorithm and the national topographic maps in the chosen scale gave promising results. In future work, we are planning to extend the algorithm so that it will be able to provide modelling of different terrains in the region.

Hydraulic Transport of Sand/Shell Mixtures

2011 ◽  
Author(s):  
Robert C. Ramsdell ◽  
Sape A. Miedema ◽  
Arno M. Talmon
Keyword(s):  
Mathematical Model ◽  
Critical Velocity ◽  
Cross Section ◽  
Settling Velocity ◽  
Hydraulic Transport ◽  
Erosion Process ◽  
Large Area ◽  
Small Cross Section ◽  
Horizontal Cross Section ◽  
Sand Particles

When considering pumping shells through a pipeline we have to consider that the shells are not spherical, but more discs shaped. When shells settle they will settle like leaves where the biggest cross section is exposed to the drag. But when they settle, they will settle in the same orientation, flat on the sediment, so the sides of the shells are exposed to the horizontal flow in the pipeline. Since the side cross section is much smaller than the horizontal cross section, a much higher velocity is required to make them erode and go back into suspension. The settling velocity is much smaller because of the large area of the cross section. Even when the slurry velocity exceeds the settling velocity, there will always be some shells that will reach the bottom of the pipe due to the combination of settling velocity and turbulence. Once these shells are on top of the sediment they are hard to remove by erosion, because they lay flat on the surface and have a small cross section that is exposed to the flow compared with the weight of the shell. So although their settling velocity is much lower than equivalent sand particles, the erosion velocity is much higher. If we look at the beach in an area with many shells, we can always see the shells on top of the sand, covering the sand. In fact the shells are shielding the sand from erosion, because they are hard to erode. The bigger shells will also shield the smaller pieces, because the smaller pieces settle faster. Compare this with leaves falling from a tree, the bigger leaves, although heavier, will fall slower, because they are exposed to higher drag. The same process will happen in the pipeline. Shells settle slower than sand grains, so they will be on top of the bed (if there is a bed), just like on the beach. Since they are hard to erode, in fact they protect the bed from being eroded, even if the line speed is increased. The combination of high erosion velocity and the shell ‘protecting’ the bed means that even a small amount of shells can lead to relatively thick bed in the pipeline. But there will always be velocities above the bed that will make the shells erode. The paper describes the settling and erosion process of shells and the consequences of this on the critical velocity when pumping a sand/shell mixture through a pipeline. A mathematical model of the processes involved will be presented.

CdTe Thin-Film Solar Cells

MRS Bulletin ◽  
1993 ◽  
Vol 18 (10) ◽  
pp. 45-47 ◽  
Author(s):  
T. Suntola
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Cadmium Telluride ◽  
High Efficiency ◽  
Low Cost ◽  
Thick Layer ◽  
Thin Film Solar Cells ◽  
Cdte Thin Film ◽  
Large Area ◽  
Cell Structures

Cadmium telluride is currently the most promising material for high efficiency, low-cost thin-film solar cells. Cadmium telluride is a compound semiconductor with an ideal 1.45 eV bandgap for direct light-to-electricity conversion. The light absorption coefficient of CdTe is high enough to make a one-micrometer-thick layer of material absorb over 99% of the visible light. Processing homogenous polycrystalline thin films seems to be less critical for CdTe than for many other compound semiconductors. The best small-area CdTe thin-film cells manufactured show more than 15% conversion efficiency. Large-area modules with aperture efficiencies in excess of 10% have also been demonstrated. The long-term stability of CdTe solar cell structures is not known in detail or in the necessary time span. Indication of good stability has been demonstrated. One of the concerns about CdTe solar cells is the presence of cadmium which is an environmentally hazardous material.

Post-Angioplastic Contact Mechanics With Different Levels of Artherosclerotic Plaque

2010 ◽  
Author(s):  
M. Teodorescu ◽  
H. Rahnejat ◽  
Moshe Brand ◽  
Jacob Rosen
Keyword(s):  
Cross Section ◽  
Open Space ◽  
Arterial Wall ◽  
Thick Layer ◽  
Local Interaction ◽  
Plaque Deposition ◽  
Fundamental Understanding ◽  
Layer Contact ◽  
Last Stage ◽  
Different Levels

The main goal of balloon angioplasty is to extend the active cross-section of a partly blocked artery. In the last stage of the medical operation, a metallic frame (stent) is introduced in the open space of the artery (lumen) and expanded to the desired diameter. It is generally accepted that some of the main causes of post-angioplasty restenosis are the global stresses induced in the artery by the expanding stent and the local interaction between the stent and the arterial wall. In a blocked artery a thick layer of hard plaque deposition usually covers a significant section of the wall. Therefore, to choose an appropriate stent and improve upon the angioplasty success rate, a fundamental understanding of the local interaction between the stent and the plaque, as well as between the stent and the healthy wall is vital. The goal of the present study is to find a correlation between the local thickness of the plaque layer, contact geometry and the stent/artery radial mismatch.

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