scholarly journals Particularities of Grey Alder (Alnus incana) Stands in Riparian Galleries Along Streams of the Southern Transylvanian Tableland (Romania)

2019 ◽  
Vol 21 (2) ◽  
pp. 23-40
Author(s):  
Erika Schneider-Binder
Keyword(s):  
Grain Size ◽  
Geological Structure ◽  
Alnus Incana ◽  
Alluvial Deposits ◽  
Sedimentary Deposits ◽  
Rivers And Streams ◽  
Different Grain Size

Abstract Grey Alder (Alnus incana (L.) Moench.) stands are distributed in the Carpathian area on alluvial deposits with sediments of different grain size as galleries along rivers and streams of the sub-montane to the middle montane level. The geological structure (Tertiary sedimentary deposits) in relation to the hydromorphological processes is the base for the structure of the stream valleys, which are in part very deep. Under the special microclimate of these deeper stream stretches with lower temperatures there are favourable conditions for the development of grey alder stands.

scholarly journals Innovative strategies for high resolution site characterization: application to a flood plain

2014 ◽  
Vol 3 (4) ◽  
Author(s):  
Thomas Vienken ◽  
Manuel Kreck ◽  
Jörg Hausmann ◽  
Ulrike Werban ◽  
Peter Dietrich
Keyword(s):  
Hydraulic Properties ◽  
Test Site ◽  
Flood Plain ◽  
Site Characterization ◽  
Geological Structure ◽  
Small Scale ◽  
Alluvial Deposits ◽  
Innovative Strategies ◽  
Sedimentary Deposits

Solving complex hydrogeological problems often requires a thorough understanding of (hydro-) geological subsurface conditions. This is especially true for sedimentary deposits with complex architecture, where lithology and/or hydraulic properties can significantly vary over short horizontal and vertical distances. At these sites, a traditional, solely sample-based investigation approach is often not applicable due to limited data accuracy, resolution, and efficiency. Instead, an adapted investigation approach is required that combines exploration technologies of different resolution and investigation scales. This paper aims to demonstrate the feasibility of such a multi-scale approach for the characterization of a test site near the city of Löbnitz, Germany, that is comprised of heterogeneous alluvial deposits. Our focus is on site characterization in terms of lithology and hydraulic properties, as well as on the delineation and characterization of an aggradated oxbow as a typical example of a small scale geological structure.

Study on the Behavior of the Cast-Iron Bonded Grinding Wheel to Machining Properties of Hard and Brittle Materials

2007 ◽  
Vol 24-25 ◽  
pp. 229-232
Author(s):  
S.L. Ma ◽  
Wei Li ◽  
Cong Rong Zhu ◽  
J. Zhang ◽  
H.C. Ye
Keyword(s):  
Grain Size ◽  
Cast Iron ◽  
Tungsten Carbide ◽  
Surface Quality ◽  
Ground Surface ◽  
Grinding Wheel ◽  
Different Grain Size ◽  
Grinding Efficiency ◽  
Machining Properties

Tungsten carbide which is a hard and brittle material was ground by cast-iron bonded diamond wheel with ELID (Electrolytic In-Process Dressing) technique, for the purpose of getting high efficiency, super-precision machining. Three kinds of cast-iron bonded diamond wheels with different grain size were adopted to get different grinding efficiency and surface quality of workpieces. The grinding properties of cast-iron bonded grinding wheels with different grain size and the ground surface quality of tungsten carbide are discussed in this paper. The experiment results indicate that, under the same feeding amount, the grinding efficiency of the wheel with bigger grain size is higher, and it could make the dimension accuracy of the workpiece controllable, but the wheel with smaller grain size could get better ground surface quality. The two grinding phases are decided by the ratio between the size of abrasive grain and the thickness of the oxide layer on the grinding wheel.

scholarly journals Improvement ratio and behavior of bearing capacity factors for strip skirt footing model resting on sand of different grain size distribution

2018 ◽  
Vol 162 ◽  
pp. 01026
Author(s):  
Mahmood Rashid Mahmood
Keyword(s):  
Grain Size ◽  
Bearing Capacity ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Coarse Sand ◽  
Linear Increase ◽  
Angle Of Internal Friction ◽  
Theoretical Approaches ◽  
Different Grain Size ◽  
Improvement Ratio

Plain strain model tests were performed on beds of sands with different particle size distribution (Coarse, Medium and Fine) prepared at loose state (Relative density Dr. of 30%). A strip footing model with skirt was placed on the bed of sand and loaded vertically up to failure at different ratios of skirt depth to width D/B of (0.5, 1.0, 1.5, 2, and 3). The applied stress increments and the corresponding settlements were measured. The improvement ratio due to different skirt depth and the behavior of bearing capacity parameters Nγ and Nq at each depth were evaluated and compared with some theoretical approaches. The test results revealed that the improvement ratio increased linearly up to D/B of 1.5 then reduced. Two factors were introduce into the general bearing capacity equation where used to evaluate bearing capacity of skirt footing, there values are about 1.6 for skirt ratio ranged between 0.5 to 1.5, and 1.25 for skirt ratio more than 1.5. Also, it is found that the Nγ parameter for D/B=0 were very close to Vesic proposal for fine and medium grain size distribution, while it’s close to Biarez proposal for coarse sand. The behavior of Nq parameter with different skirt ratio shows slight increase up to D/B of 1.5 then decrease with increasing D/B ratio for different grain size distribution. While the behavior of theoretical Nq parameter (depending on angle of internal friction values) shows a linear increase with skirt ratio for different grain size distribution.

scholarly journals Study of Dissipation Properties and Structure Evolution in Metals with Different Grain Size under HCF and VHCF Loadings

2016 ◽  
Vol 2 ◽  
pp. 2084-2090 ◽  
Author(s):  
O. Plekhov ◽  
O. Naimark ◽  
M. Narykova ◽  
A. Kadomtsev ◽  
V. Betechtin
Keyword(s):  
Grain Size ◽  
Structure Evolution ◽  
Different Grain Size

Physical Properties and Structure of the Near Subsurface in the Săcel Area, Romania, from Shallow Seismic Measurements

2019 ◽  
Vol 24 (1) ◽  
pp. 151-158
Author(s):  
Ionelia Panea
Keyword(s):  
Wave Velocity ◽  
Signal To Noise Ratio ◽  
Soil Surface ◽  
Geological Structure ◽  
P Wave ◽  
S Wave ◽  
Sedimentary Deposits ◽  
Shallow Seismic ◽  
P Wave Velocity ◽  
Good Signal

Results are presented for shallow seismic reflection measurements performed southwest of Săcel village in Romania for the purpose of obtaining information about the geological structure in the near subsurface. The P-wave and S-wave velocity distributions were also obtained below the soil surface. The measurements were performed along a nearly linear profile on the top of an elongated hill. Most of the shot gathers were characterized by a good signal-to-noise ratio. A depth-converted migrated section was obtained after the processing of shot gathers, on which an image of sedimentary deposits with various thicknesses, separated by shallow faults until a depth of about 80 m, were observed. The P-wave and S-wave velocity-depth models for two segments were of considerable interest for a geotechnical study proposed for the construction of a windmill park. The two- and three-layered P-wave velocity-depth models were comparable until depths of about 10 m after first-arrival traveltime inversions. The lateral variations in the subsurface geological structure and lithology reflected the variations in the P-wave velocity values from both models. The S-wave velocity-depth models for comparable depth intervals were similar to those from the P-wave velocity-depth models. Reliable S-wave velocity distributions were obtained after inversion of fundamental-mode and higher-mode surface waves.

The investigation of K-shell fluorescence parameters of Zn-Fe alloys with different grain size and microstrain values

2017 ◽  
Vol 46 (4) ◽  
pp. 242-251 ◽  
Author(s):  
N. Kup Aylikci ◽  
J.M. Sampaio ◽  
A. Kahoul ◽  
V. Aylikci ◽  
I.H. Karahan ◽  
...  
Keyword(s):  
Grain Size ◽  
Fluorescence Parameters ◽  
Fe Alloys ◽  
Different Grain Size
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