FINE RESOLUTION IMAGERY AND GIS FOR INVESTIGATING THE MORPHOLOGICAL CHARACTERISTICS, AND MIGRATION RATE OF BARCHAN DUNES IN THE ERG SIDI MOUSSA DUNEFIELD NEAR IN-SALAH (ALGERIA)

The present research was conducted to determine the morphometry, morphology, and temporal and spatialbehavior of individual barchans in the Lut Desert in Iran. This region is one of the driest places in the world andthere is a little information about the geomorphology of this region, especially on the barchans. Therefore, herein,a total of 391 individual barchan dunes were selected and their morphometric parameters were compared withrespect to the length/width (a/c) ratios (extraordinarily slim to fat barchans), migration rate, direction of movementand influence of wind regime on this landform. The results showed big difference in the morphology, morphometry,and direction and migration rate of barchans between the western and eastern parts of the Lut Desert. The meanmigration rate was about 5.17 m/yr in the study area and ranged between 1.1 and 15.35 m/yr. The annual sand driftpotential was equal to 1053.9 VU in the western part and 803.6VU in the eastern part of the Lut Desert and it wasclassified as high-energy wind environment. The NNW direction (620 VU) in the west as well as the SSW direction(100 VU) had a high effect on the movement of barchans. Their direction of movement ranged from northwest tosoutheast in the western part and from southwest to northeast in the eastern part, which were correlated with thedominant wind directions in these regions. Results of measuring the morphometric parameters of the barchansindicated that mean length, width, height, and maximum length of barchans were equal to 114.5, 179.5, 10.47, and590.2 m, respectively which are relatively high in comparison with data for other barchans studied in some previousresearches in the world. The shape of barchans was classified into slim, normal, pudgy, or fat and extraordinarilyslim. Most of them were slim (166 barchans, 42.5%) and their distribution differed between the eastern and westernparts of the Lut Desert. This can be attributed to local physical situations and wind direction properties.

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A Long-Term Fine-Resolution Record of AVHRR Surface Temperatures for the Laurentian Great Lakes

Remote Sensing ◽

10.3390/rs10081210 ◽

2018 ◽

Vol 10 (8) ◽

pp. 1210

Author(s):

Charles White ◽

Andrew Heidinger ◽

Steven Ackerman ◽

Peter McIntyre

Keyword(s):

Great Lakes ◽

Morphological Characteristics ◽

Laurentian Great Lakes ◽

Environmental Research ◽

Weighted Interpolation ◽

Large Lakes ◽

Fine Resolution ◽

Observation Times ◽

The Impact

Inland waters are warming at highly variable rates that often differ from regional air temperature trends. This variable warming is partially attributable to an individual lake’s geographical and morphological characteristics. In very large lakes, significant intralake variability in long-term warming trends has also been observed. In light of this intralake and interlake heterogeneity of lake surface water temperature (LSWT) and LSWT trends, we revisit the 1.1 km Advanced Very High Resolution Radiometer (AVHRR) record for the Laurentian Great Lakes. In this work, we have assembled a long-term (1986–2016) and high-spatial-resolution (0.018°) daily LSWT dataset using AVHRR record. Subtracting an empirically-determined mean diurnal cycle mitigates the effects of varying observation times. Adjustments in the georegistration of the images are made to reduce the impact of AVHRR navigational errors on the earlier platforms. Both the original daily composites, and a gap-filled product using locally weighted interpolation methods will be made available to support fine-scale physical and environmental research in the region.

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Evaluation of Preosteoblast MC3T3-E1 Cells Cultured on a Microporous Titanium Membrane Fabricated Using a Precise Mechanical Punching Process

Materials ◽

10.3390/ma13225288 ◽

2020 ◽

Vol 13 (22) ◽

pp. 5288

Author(s):

Jingyu Zhang ◽

Yukihiko Sakisaka ◽

Hiroshi Ishihata ◽

Kentaro Maruyama ◽

Eiji Nemoto ◽

...

Keyword(s):

Morphological Characteristics ◽

Limited Information ◽

Expression Levels ◽

Promote Cell Proliferation ◽

Proliferation And Differentiation ◽

Punching Process ◽

And Migration ◽

Titanium Membrane ◽

Migration Of Cells ◽

Gene Expression Levels

The surface topography of Titanium (Ti) combined toughness and biocompatibility affects the attachment and migration of cells. Limited information of morphological characteristics, formed by precise machining in micron order, is currently available on the Ti that could promote osteoconduction. In the present study, a pure Ti membrane was pierced with precise 25 μm square holes at 75 μm intervals and appear burrs at the edge of aperture. We defined the surface without burrs as the “Head side” and that with burrs as the “Tail side”. The effects of the machining microtopography on the proliferation and differentiation of the preosteoblasts (MC3T3-E1 cells) were investigated. The cells were more likely to migrate to, and accumulate in, the aperture of holes on the head side, but grew uniformly regardless of holes on the tail side. The topography on the both surfaces increased osteopontin gene expression levels. Osteocalcin expression levels were higher on the head side than one on the blank scaffold and tail side (p < 0.05). The osteocalcin protein expression levels were higher on the tail side than on the head side after 21 days of cultivation, and were comparable to the proportion of the calcified area (p < 0.05). These results demonstrate the capacity of a novel microporous Ti membrane fabricated using a precise mechanical punching process to promote cell proliferation and activity.

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RS CVn STARS: Photospheric Phenomena and Rotation

International Astronomical Union Colloquium ◽

10.1017/s0252921100096299 ◽

1983 ◽

Vol 71 ◽

pp. 343-361

Author(s):

S. Catalano

Keyword(s):

Migration Rate ◽

Orbital Motion ◽

Rotation Period ◽

Maximum Amplitude ◽

Activity Level ◽

Period 2 ◽

Rs Cvn Stars ◽

Activity Cycles ◽

And Migration ◽

Wave Migration

ABSTRACTThis review presents a summary of observed photospheric phenomena on RS CVn stars: the amplitude, shape, evolution and migration rate of the photometric wave in relation to the rotational and orbital motion.The main points considered are: 1) the activity level (maximum amplitude, short and long timescale variability) versus rotation period; 2) the activity cycles as inferred from changes in the wave migration rate and direction and from the variation of its amplitude; 3) the detection of differential rotation; 4) the connection between the orbital period variation and activity.

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Coherency Strain Energy in any Crystal System: Applications to in Situ Observations of Cigm in Calcite

MRS Proceedings ◽

10.1557/proc-205-245 ◽

1990 ◽

Vol 205 ◽

Author(s):

R.S. May ◽

B. Evans

Keyword(s):

Driving Force ◽

Migration Rate ◽

Strain Energy ◽

Solute Concentration ◽

Coherency Strain ◽

Solute Diffusion ◽

Boundary Orientation ◽

In Situ Observations ◽

And Migration

AbstractIn situ observations of CIGM in CaCO3 bicrystals with a SrCO3 solute source were made. The change in boundary orientation and migration rate were compared with solute concentration. The liquid film model for coherency strain Induced migration was generalized to any non-cubic system and applied to CaCO3-SrCO3. The coherent layer was modeled as a thin film on an infinite half-space. The strain energy was found from solution of the Hooke's law expressions transformed to the appropriate coordinate system. For triclinic or monoclinic films the strain tensor was found by an eigenvector decomposition of the transformation matrix that defined the lattice parameter change with composition. High anisotropy of Vegard's law constants for CaCO3-SrCO3 caused (111) to have the lowest coherency strain per unit solute. Surfaces perpendicular to (111) in coherent equilibria were predicted to have half the solute concentration and three times the migration driving force of those perpendicular to (111). However, no correlation between solute concentration and boundary orientation was observed. Ambiguous and contradictory evidence for a relationship between solute concentration, boundary orientation, and migration rate was found. The self-stress state of a grain boundary in a solute diffusion field may be better modelled as hydrostatic rather than plane stress. Hydrostatic compression may interact with the boundary excess volume and cause a PV driving force for migration. Predictions based on coherent equilibrium at a surface have not been tested for that geometry in calcite; they should be tested before they are applied to grain boundaries.

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EUS-guided gold fiducial placement and migration rate

Gastrointestinal Endoscopy ◽

10.1016/j.gie.2014.03.028 ◽

2014 ◽

Vol 80 (3) ◽

pp. 533-534 ◽

Cited By ~ 4

Author(s):

Lorenzo Fuccio ◽

Gabriele Lami ◽

Alessandra Guido ◽

Carlo Fabbri

Keyword(s):

Migration Rate ◽

And Migration

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Subaqueous barchan dunes in turbulent shear flow. Part 1. Dune motion

Journal of Fluid Mechanics ◽

10.1017/s0022112011000139 ◽

2011 ◽

Vol 675 ◽

pp. 199-222 ◽

Cited By ~ 48

Author(s):

E. M. FRANKLIN ◽

F. CHARRU

Keyword(s):

Erosion Rate ◽

Friction Velocity ◽

Turbulent Channel Flow ◽

Minimum Size ◽

Turbulent Shear ◽

Turbulent Shear Flow ◽

Rate Minimum ◽

Flow Part ◽

Barchan Dunes ◽

And Migration

Experiments are reported on the formation and migration of isolated dunes in a turbulent channel flow. These dunes have a very robust crescentic shape with horns pointing downstream, very similar to that of the barchan dunes observed in deserts at a much larger scale. Their main geometrical and dynamical properties are studied in detail, for four types of grains: the conditions for their formation, their morphology, the threshold shear stress for their motion, their velocity, erosion rate, minimum size and the longitudinal stripes of grains hollowed by fluid streaks in the boundary layer. In particular, the law for the dune velocity is found to involve two dimensionless parameters, the Shields number and the sedimentation Reynolds number, in contrast with predictions based on classical laws for particle transport. As the dune migrates, its size slowly decreases because of a small leakage of particles at the horn tips, and the erosion law is given. A minimum size is evidenced, which is shown to increase with the friction velocity and scale with a settling length.

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