scholarly journals Speleogenesis of the Jankova pecina cave and karst in it's nearby vicinity

2014 ◽  
Vol 94 (4) ◽  
pp. 77-90
Author(s):  
Mirela Djurovic ◽  
Predrag Djurovic
Keyword(s):  
Partial Removal ◽  
Erosion Processes ◽  
Opposite Process ◽  
Air Circulation ◽  
Insight Into

This paper provides the insight into morpho-hydrologic characteristics and speleogenesis of the Jankova pecina cave and the evolution of karst in the nearby vicinity. Phases in cave evolution, which represents the alternation of accumulative and erosion processes, were analysed. Clogging of existed conduits during the first accumulative phase leads to displacement of the Janko's creek abyss and formation of another entrance along with new, deeper storaged conduits. The strewed parts of the cave were exposed to partial removal of sediments what resulted in exhumation of its oldest products. The opening of the quite new entrance (vigled) during the opposite process and phase of clogging the endure air circulation inside the cave has been changed. As the consequence, the asymmetric forms of stalactites and stalagmites formed. Study of the Jankova pecina cave represents a contribution to better knowledge of accumulative processes as a significant speleogenetic factor.

Tectonics and geomorphology

2010 ◽  
Vol 34 (3) ◽  
pp. 357-383 ◽  
Author(s):  
Simon H. Brocklehurst
Keyword(s):  
Numerical Models ◽  
Tectonic Geomorphology ◽  
Topographic Analysis ◽  
Erosion Processes ◽  
Field Data Collection ◽  
Analysis Laboratory ◽  
Widespread Availability ◽  
State Of Tension ◽  
Hillslope Processes ◽  
Insight Into

The field of tectonic geomorphology is in a state of tension. The widespread availability of high-quality, high-resolution digital topographic data encourages the development of simple morphological ‘tools’ which can be used to deduce recent tectonic evolution. Meanwhile, process geomorphologists recognize that current models have a significant empirical basis, and lack insight into the underlying physics of erosion processes. Most tectonic geomorphology research is concerned with rivers, but glaciers, debris flows and hillslope processes also play a key role in hypotheses linking climate to tectonics, via surface processes, while submarine geomorphology has barely been investigated in a tectonic context. Studies combining field data collection, exposure, burial and low-temperature thermochronologic dating, digital topographic analysis, laboratory experiments and numerical models are successfully incorporating physics into geomorphic process ‘laws’, and demonstrating key tectonic geomorphology hypotheses. The approaches required for further progress have been outlined, but many exciting challenges remain.

scholarly journals Finding Possible Weakness in the Runoff Simulation Experiments to Assess Rill Erosion Changes without Non-Intermittent Surveying Capabilities

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6254
Author(s):  
Alexander André Remke ◽  
Jesus Rodrigo-Comino ◽  
Stefan Wirtz ◽  
Johannes B. Ries
Keyword(s):  
3D Models ◽  
Rill Erosion ◽  
Runoff Simulation ◽  
Simulation Experiments ◽  
Erosion Processes ◽  
Camera Array ◽  
Point Density ◽  
Before And After ◽  
Insight Into ◽  
Terrestrial Photogrammetry

The Terrestrial Photogrammetry Scanner (TEPHOS) offers the possibility to precisely monitor linear erosion features using the Structure from Motion (SfM) technique. This is a static, multi-camera array and dynamically moves the digital videoframe camera designed to obtain 3-D models of rills before and after the runoff experiments. The main goals were to (1) obtain better insight into the rills; (2) reduce the technical gaps generated during the runoff experiments using only one camera; (3) enable the visual location of eroded, transported and accumulated material. In this study, we obtained a mean error for all pictures reaching up to 0.00433 pixels and every single one of them was under 0.15 pixel. So, we obtained an error of about 1/10th of the maximum possible resolution. A conservative value for the overall accuracy was one pixel, which means that, in our case, the accuracy was 0.0625 mm. The point density, in our example, reached 29,484,888 pts/m2. It became possible to get a glimpse of the hotspots of sidewall failure and rill-bed incision. We conclude that the combination of both approaches—rill experiment and 3D models—will make easy under laboratory conditions to describe the soil erosion processes accurately in a mathematical–physical way.

scholarly journals Geodetic and UAV Monitoring in the Sustainable Management of Shallow Landslides and Erosion of a Susceptible Urban Environment

2021 ◽  
Vol 13 (3) ◽  
pp. 385
Author(s):  
Paul Sestras ◽  
Ștefan Bilașco ◽  
Sanda Roșca ◽  
Branislav Dudic ◽  
Artan Hysa ◽  
...  
Keyword(s):  
Valuable Insight ◽  
Prevention Measures ◽  
Hilly Terrain ◽  
Erosion Processes ◽  
Area Of Interest ◽  
Active Landslide ◽  
The City ◽  
Construction Zones ◽  
Insight Into ◽  
A Current

Landslides are a worldwide occurring hazard that can produce economic impact and even fatalities. The collection and monitoring of data regarding active landslides are important for predicting future landslides in that region, and is critical to minimize the losses caused. In the expanding metropolitan area of Cluj-Napoca, Romania, drastic changes of land use and increasement of construction zones represent a current evolution issue. The urban sprawl phenomenon imposed the expansion of the city limits and outside the old built-up area, and due to the hilly terrain and geomorphology, natural hazards such as landslides and erosion processes are susceptible to appearance or reactivation. The study incorporates interdisciplinary research composed of evaluation of a landslide susceptible hotspot located in an area of interest to the municipality by means of geodetic and topographic precise measurements, combined with the use of unmanned aerial vehicles (UAV) monitoring of surface movement and GIS spatial analysis. The data obtained in a span of over two years reveal that the investigated slope is subjected to a shallow active landslide of a few centimeters per year, and based on the 64 individual placed landmarks the highest displacement value was 67 mm. Through geomatic tools the exchange rate of the slope surface was evaluated with comprehensive volume calculations, such as displacement, erosion, and accumulation that illustrate a volume of material displaced of 107.2 m3 and the accumulated one of 55.7 m3. The results provide valuable insight into the complex landslide and erosion dynamics that are crucial when predicting future movements and prevention measures.

scholarly journals Printable elastomeric electrodes with sweat-enhanced conductivity for wearables

2021 ◽  
Vol 7 (29) ◽  
pp. eabg8433
Author(s):  
Jian Lv ◽  
Gurunathan Thangavel ◽  
Yi Li ◽  
Jiaqing Xiong ◽  
Dace Gao ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Wearable Devices ◽  
Urethane Acrylate ◽  
Wearable Electronics ◽  
Partial Removal ◽  
Current Collectors ◽  
Human Sweat ◽  
Silver Flakes ◽  
Enhanced Conductivity ◽  
Insight Into

We rationally synthesized the thermoplastic and hydrophilic poly(urethane-acrylate) (HPUA) binder for a type of printable and stretchable Ag flakes–HPUA (Ag-HPUA) electrodes in which the conductivity can be enhanced by human sweat. In the presence of human sweat, the synergistic effect of Cl− and lactic acid enables the partial removal of insulating surfactant on silver flakes and facilitates sintering of the exposed silver flakes, thus the resistance of Ag-HPUA electrodes can be notably reduced in both relaxed and stretched state. The on-body data show that the resistance of one electrode has been decreased from 3.02 to 0.62 ohm during the subject’s 27-min sweating activity. A stretchable textile sweat-activated battery using Ag-HPUA electrodes as current collectors and human sweat as the electrolyte was constructed for wearable electronics. The enhanced conductivity of the wearable wiring electrode from the reaction with sweat would provide meritorious insight into the design of wearable devices.

Calibration problems in hydrogen luminosities

1966 ◽  
Vol 24 ◽  
pp. 322-330
Author(s):  
A. Beer
Keyword(s):  
Galactic Structure ◽  
B Stars ◽  
Insight Into

The investigations which I should like to summarize in this paper concern recent photo-electric luminosity determinations of O and B stars. Their final aim has been the derivation of new stellar distances, and some insight into certain patterns of galactic structure.

Stochasting modeling of planetary ring systems

1984 ◽  
Vol 75 ◽  
pp. 461-469 ◽  
Author(s):  
Robert W. Hart
Keyword(s):  
Maximum Entropy ◽  
Ring System ◽  
The Sun ◽  
Ultimate State ◽  
Interparticle Interactions ◽  
Ring Systems ◽  
First Order ◽  
Planetary Ring ◽  
Insight Into

ABSTRACTThis paper models maximum entropy configurations of idealized gravitational ring systems. Such configurations are of interest because systems generally evolve toward an ultimate state of maximum randomness. For simplicity, attention is confined to ultimate states for which interparticle interactions are no longer of first order importance. The planets, in their orbits about the sun, are one example of such a ring system. The extent to which the present approximation yields insight into ring systems such as Saturn's is explored briefly.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Structure and function of neural networks in the retina

1988 ◽  
Vol 46 ◽  
pp. 26-27
Author(s):  
Peter Sterling
Keyword(s):  
Ganglion Cells ◽  
Three Dimensional ◽  
Structure And Function ◽  
Synaptic Connections ◽  
Visual Axis ◽  
One Dimensional ◽  
Cat Retina ◽  
Ultrathin Sections ◽  
And Function ◽  
Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

Radiation Damage Studies with the HVEM

1972 ◽  
Vol 30 ◽  
pp. 680-681
Author(s):  
J. J. Laidler ◽  
B. Mastel
Keyword(s):  
Radiation Damage ◽  
Stainless Steels ◽  
Volume Expansion ◽  
Austenitic Stainless Steels ◽  
Test Facility ◽  
Fast Breeder Reactors ◽  
Breeder Reactors ◽  
Under Construction ◽  
Development Laboratory ◽  
Insight Into

One of the major materials problems encountered in the development of fast breeder reactors for commercial power generation is the phenomenon of swelling in core structural components and fuel cladding. This volume expansion, which is due to the retention of lattice vacancies by agglomeration into large polyhedral clusters (voids), may amount to ten percent or greater at goal fluences in some austenitic stainless steels. From a design standpoint, this is an undesirable situation, and it is necessary to obtain experimental confirmation that such excessive volume expansion will not occur in materials selected for core applications in the Fast Flux Test Facility, the prototypic LMFBR now under construction at the Hanford Engineering Development Laboratory (HEDL). The HEDL JEM-1000 1 MeV electron microscope is being used to provide an insight into trends of radiation damage accumulation in stainless steels, since it is possible to produce atom displacements at an accelerated rate with 1 MeV electrons, while the specimen is under continuous observation.

Failure Analysis With the Scanning Electron Microscope

1972 ◽  
Vol 30 ◽  
pp. 482-483
Author(s):  
John R. Devaney
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Integrated Circuits ◽  
Failure Analysis ◽  
High Reliability ◽  
Military Applications ◽  
Small Structure ◽  
Useful Life ◽  
Insight Into ◽  
Scanning Electron

Occasionally in history, an event may occur which has a profound influence on a technology. Such an event occurred when the scanning electron microscope became commercially available to industry in the mid 60's. Semiconductors were being increasingly used in high-reliability space and military applications both because of their small volume but, also, because of their inherent reliability. However, they did fail, both early in life and sometimes in middle or old age. Why they failed and how to prevent failure or prolong “useful life” was a worry which resulted in a blossoming of sophisticated failure analysis laboratories across the country. By 1966, the ability to build small structure integrated circuits was forging well ahead of techniques available to dissect and analyze these same failures. The arrival of the scanning electron microscope gave these analysts a new insight into failure mechanisms.

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