scholarly journals Sedimentological characterization of Antarctic moraines using UAVs and Structure-from-Motion photogrammetry

2015 ◽  
Vol 61 (230) ◽  
pp. 1088-1102 ◽  
Author(s):  
Matthew J. Westoby ◽  
Stuart A. Dunning ◽  
John Woodward ◽  
Andrew S. Hein ◽  
Shasta M. Marrero ◽  
...  
Keyword(s):  
Grain Size ◽  
Structure From Motion ◽  
Laser Scanning ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Traditional Methods ◽  
Continuous Map ◽  
Scale Modelling ◽  
Grain Size Distributions ◽  
Patch Scale

AbstractIn glacial environments particle-size analysis of moraines provides insights into clast origin, transport history, depositional mechanism and processes of reworking. Traditional methods for grain-size classification are labour-intensive, physically intrusive and are limited to patch-scale (1 m2) observation. We develop emerging, high-resolution ground- and unmanned aerial vehicle-based ‘Structure-from-Motion’ (UAV-SfM) photogrammetry to recover grain-size information across a moraine surface in the Heritage Range, Antarctica. SfM data products were benchmarked against equivalent datasets acquired using terrestrial laser scanning, and were found to be accurate to within 1.7 and 50 mm for patch- and site-scale modelling, respectively. Grain-size distributions were obtained through digital grain classification, or ‘photo-sieving’, of patch-scale SfM orthoimagery. Photo-sieved distributions were accurate to <2 mm compared to control distributions derived from dry-sieving. A relationship between patch-scale median grain size and the standard deviation of local surface elevations was applied to a site-scale UAV-SfM model to facilitate upscaling and the production of a spatially continuous map of the median grain size across a 0.3 km2 area of moraine. This highly automated workflow for site-scale sedimentological characterization eliminates much of the subjectivity associated with traditional methods and forms a sound basis for subsequent glaciological process interpretation and analysis.

Soil Particle Size Analysis Using X-Ray Absorption

1996 ◽  
Vol 1548 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Stanley J. Vitton ◽  
Carl C. Nesbitt ◽  
Leon Y. Sadler
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Size Range ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Size Distributions ◽  
X Ray ◽  
Grain Size Distributions ◽  
X Ray Absorption ◽  
Representative Samples

The hydrometer method is the standard method of grain size analysis used in geotechnical engineering. Although the hydrometer method provides accurate grain size distributions and is relatively easy to conduct, it takes a minimum of 2 days to complete and is subject to operator error. In studies where small-magnitude changes or more rapid results are required, an alternative method to hydrometer testing is to use an automated particle size analysis instrument employing X-ray absorption. This technique passes a finely collated X-ray beam through a suspension of settling particle in a fluid. Because the intensity of the X-ray is directly related to the percentage mass of soil in a suspension, Stokes' law can be used to calculate the grain size distribution of a soil assuming an equivalent particle diameter for the soil grains. X-ray absorption has been found to produce accurate grain size distributions in the 75 μm to 1 μm size range when sample preparation adheres to AASHTO T88-90 specifications and suspension concentrations are approximately 2 percent by volume. Testing for particles sizes down to 1 μm takes approximately 20 min per sample. Technical concerns remaining involve obtaining representative samples of the soil in the 75 μm, to 1 μm size range suspension for testing. One method being evaluated is injection flow analysis, which is an inexpensive method of obtaining representative samples used with a variety of inorganic, industrial, and environmental materials in which direct sampling of fluid is required.

scholarly journals A Comparison of Grain Size Measurements in Al-Cu Thin Films: Imaging Vs. Diffraction Techniques

2002 ◽  
Vol 10 (6) ◽  
pp. 5-9 ◽  
Author(s):  
L.M. Gignac ◽  
C.E. Murray ◽  
K.P. Rodbell ◽  
M. Gribelyuk
Keyword(s):  
Grain Size ◽  
Measurement Techniques ◽  
Measurement Range ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Analysis Methodology ◽  
Grain Structures ◽  
Grain Size Distributions ◽  
Major Factors ◽  
Microscopy Techniques

Numerous microscopy techniques, based on both imaging and diffraction, exist for the measurement of grain size distributions in polycrystalline thin-film samples. The accuracy of each technique is affected by three major factors: the effective resolution of the instrument relative to the characteristic grain size, the detection of the grain size through the thickness of the film, and the recognition of boundaries between adjacent grains during post-processing. When the instrument resolution is primarily considered, the measurement technique has a practical grain size measurement range, see Fig. 1 for a comparison of ranges for several measurement techniques. In bulk metallurgy grain size analysis, methodology has been developed to represent 3-dimensionai grain structures from measurements taken on 2-dimensional images.

scholarly journals GRAINet: mapping grain size distributions in river beds from UAV images with convolutional neural networks

2021 ◽  
Vol 25 (5) ◽  
pp. 2567-2597
Author(s):  
Nico Lang ◽  
Andrea Irniger ◽  
Agnieszka Rozniak ◽  
Roni Hunziker ◽  
Jan Dirk Wegner ◽  
...  
Keyword(s):  
Grain Size ◽  
Training Data ◽  
Grain Size Analysis ◽  
Training Dataset ◽  
Size Analysis ◽  
Size Distributions ◽  
Mean Diameter ◽  
Grain Size Distributions ◽  
Gravel Bars ◽  
Uav Images

Abstract. Grain size analysis is the key to understand the sediment dynamics of river systems. We propose GRAINet, a data-driven approach to analyze grain size distributions of entire gravel bars based on georeferenced UAV images. A convolutional neural network is trained to regress grain size distributions as well as the characteristic mean diameter from raw images. GRAINet allows for the holistic analysis of entire gravel bars, resulting in (i) high-resolution estimates and maps of the spatial grain size distribution at large scale and (ii) robust grading curves for entire gravel bars. To collect an extensive training dataset of 1491 samples, we introduce digital line sampling as a new annotation strategy. Our evaluation on 25 gravel bars along six different rivers in Switzerland yields high accuracy: the resulting maps of mean diameters have a mean absolute error (MAE) of 1.1 cm, with no bias. Robust grading curves for entire gravel bars can be extracted if representative training data are available. At the gravel bar level the MAE of the predicted mean diameter is even reduced to 0.3 cm, for bars with mean diameters ranging from 1.3 to 29.3 cm. Extensive experiments were carried out to study the quality of the digital line samples, the generalization capability of GRAINet to new locations, the model performance with respect to human labeling noise, the limitations of the current model, and the potential of GRAINet to analyze images with low resolutions.

scholarly journals Synthesis of ZnO-CdO Nanocomposites

2013 ◽  
Vol 1 (1) ◽  
pp. 11-14
Author(s):  
N. Sahu ◽  
◽  
R. K. Duchaniya ◽  
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Low Cost ◽  
Sol Gel ◽  
Particle Size Analysis ◽  
Synthesis Process ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The ZnO-CdO nanocomposite was prepared by sol-gel method by using their respective nitrates. It is a simple and low cost method to prepare nanocomposites. The drying temperature and drying period of prepared gel was varied during the synthesis process. The prepared samples were characterized by using scanning electron microscope (SEM), particle size analysis (PSA), X-ray diffraction (XRD) and photoluminescence spectroscopy (PL) to get surface morphology, idea of getting particle of nanosized range so that further characterizations can be done, to study the optical property of synthesized nanocomposite and measure the band gap . The grain size determined by Scherrer’s formula was found to be between 30-50 nm.

scholarly journals Distribution and origin of anomalously high permeability zones in Weizhou formation, Weizhou 12-X oilfield, Weixinan Sag, China

2021 ◽  
Author(s):  
Guosong Chen ◽  
Yuanlin Meng ◽  
Jinlai Huan ◽  
Youchun Wang ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Grain Size ◽  
Physical Property ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Beibu Gulf ◽  
Depth Range ◽  
High Permeability ◽  
Porosity And Permeability ◽  
Permeability Increase ◽  
Seepage Channel

AbstractIn order to study the dominant seepage channel of the third member of Weizhou formation (Ew3) in Weizhou 12-X oilfield, Weixinan Sag, Beibu Gulf Basin, and tap the potential of remaining oil. The distribution and causes of the anomalously high permeability zones in Weizhou Formation were studied by using conventional core physical property analysis, scanning electron microscope, laser particle size analysis, X-ray diffraction and thin section microscopic identification. As the results show, vertically,there are three anomalously high permeability zones in the A11, A12 and A21 micro-stage of the middle diagenetic stage, with the depth range of 2300 m ~ 2400 m, 2400 m ~ 2600 m, 2600 m ~ 2900 m respectively. Grain size, sorting, dissolution and early emplacement of hydrocarbons are the main causes of anomalously high permeability zones. Although both grain size and sorting affect porosity and permeability, the effect of grain size on permeability is stronger than sorting, and sorting has a stronger effect on porosity than grain size. Magmatic hydrothermal and organic acid promote dissolution and concomitant porosity and permeability increase by dissolving unstable minerals. The early emplacement of hydrocarbons retard the cementation and accompanying porosity and permeability reduction by reducing the water-rock ratio. Finally, sandstone reservoirs in the Ew3 are characterized by anomalously high permeability zones.

scholarly journals Synthesis and Characterization of Novel Hybrid Flocculants Based on Potato Starch Copolymers with Hollow Carbon Spheres

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1498
Author(s):  
Beata Schmidt ◽  
Krzysztof Kowalczyk ◽  
Beata Zielinska
Keyword(s):  
Laser Scanning ◽  
Potato Starch ◽  
Particle Size Analysis ◽  
Laser Scanning Microscopy ◽  
Molar Ratio ◽  
Size Analysis ◽  
Carbon Spheres ◽  
Scanning Calorimetry ◽  
Kaolin Suspension ◽  
Flocculation Efficiency

Novel carbon nanofiller-based starch-g-polyacrylamide hybrid flocculation materials (St-PAM-CS) were in situ prepared using potato starch (St), acrylamide (AM), and hollow mesoporous carbon spheres (CSs; diameters of 300–400 nm). Structures of different St-PAM-CS systems were characterized by Fourier transform infrared (FTIR) spectroscopy, X-Ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), laser scanning microscopy (LSM), and particle size analysis. The flocculation tests were evaluated by removing high turbidity kaolin suspension—initial absorbance 1.84. The effect of the St to AM molar ratio, doses, and content of CSs in hybrids on flocculation efficiency were examined. Satisfactory flocculation efficiency was obtained for all hybrids with 1 wt.% of the CS component. The highest reduction of the kaolin suspension absorbance (to 0.06) was observed for a 3 mL dose of the starch hybrid with the highest AM content. Additionally, St-PAM-CS showed a reduction in the sludge volume in time. The hybrids reached better flocculation efficiency in relation to the reference systems without CSs. The proposed flocculation mechanism (considering bridging, patching, and formation of hydrogen bonds) has been confirmed by the recorded results.

scholarly journals Modern methods of grain size distribution of soils

2013 ◽  
pp. 302-308
Author(s):  
Volodymyr Radzii
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Soil Mass ◽  
Particle Size Analysis ◽  
Soil Science ◽  
Size Analysis ◽  
Ecological Functions ◽  
Modern Methods

Grain size distribution of soil determines much of water and physical properties of the soil mass. However, it defines ecological functions and morphological memory of soils in the study of their genesis, evolution and use. This article describes the main methods of particle size analysis and suggests the modern methods used increasingly in the research in soil science, geology, chemical, pharmaceutical and other industries. Key words: particle size distribution of soil, sedimentograph, laser diffraction.

High-resolution records of grain-size and depositional environment correlated to the Homo erectus Nariokotome Boy site, West Turkana, Kenya

2021 ◽  
Author(s):  
Conner O'Reilly ◽  
Catherine C. Beck ◽  
Jeroen H. van der Lubbe ◽  
Craig S. Feibel ◽  
Bruce Wegter ◽  
...  
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Homo Erectus ◽  
Eastern Africa ◽  
Coarse Grained ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Sedimentary Sequences ◽  
Grain Size Distributions ◽  
Material Grain Size

&lt;p&gt;The Turkana Basin in northern Kenya contains a robust record of hominin fossils, including Nariokotome Boy (discovered from the NK3 site), the most complete H. erectus specimen found to date. Understanding the paleoenvironmental context in which hominins such as H. erectus evolved has been an objective of decades of research in eastern Africa. Here, we present a study using grain size analyses to infer the paleoenvironmental conditions responsible for the deposition of the sedimentary sequences directly associated with NK3. We resampled a ~14 m interval at from the West Turkana Kaitio (WTK13) core, collected as part of the Hominin Sites and Paleolakes Drilling Project. This interval ties directly to the outcrop where Nariokotome Boy was recovered. By sampling continuously at 0.5 cm intervals (~7 yrs/sample), we document the paleoenvironment in ultra high-resolution (i.e. a scale relevant to a hominin life) that directly correlates to the NK3 site. Over 350 sediment samples were pre-treated to remove carbonate, biogenic silica, and other organic material from detrital material. Grain size distributions were measured on a Malvern Mastersizer 3000 using wet suspension. Based on these analyses, the interval was dominated by silt, which was further investigated using end-member modeling. A four end-member solution explained on average 99% of the population variability. The bottom of the interval was more coarse-grained, with an abrupt fining transition at 38.83 meter below surface (mbsf), which corresponds with the transition out of a tuffaceous interval (Natoo tuff) and into a pedogenically modified interval. This correlation is significant as the top of this tuff is the surface upon which Nariokotome Boy was recovered. Previous facies and grain size analyses revealed and quantified Turkana&amp;#8217;s dynamic lake level history. However, our grain size analysis provides unprecedented resolution for the paleoenvironment during which Nariokotome Boy lived. Our 0.5 cm sampling resolution enables us to quantify depositional changes on a scale comparable with previous descriptive facies analyses and to refine transitions between paleosols, fluvial deposits, and lacustrine deposition at the interface of these three paleoenvironments enabling us to reconstruct a dynamic lakeshore environment during the lifetime of the Nariokotome Boy.&lt;/p&gt;

The effect of chemical pretreatment on grain size results of past and recent clastic sediments

2020 ◽  
Author(s):  
Fruzsina Gresina ◽  
György Varga ◽  
Lili Szabó ◽  
Csilla Király ◽  
Zoltán Szalai
Keyword(s):  
Grain Size ◽  
Particle Size Analysis ◽  
Laser Diffraction ◽  
Size Analysis ◽  
Recent Sediment ◽  
Technology Support ◽  
Chemical Pretreatment ◽  
Sediment Types ◽  
Clastic Sediments ◽  
Innovation And Technology

&lt;p&gt;Laser diffraction grain size data have been widely used in paleoenvironmental reconstructions as physicochemical alteration-related proxies. Many studies are available on comparison of different laser diffraction devices, optical theories and optical settings. The ignorance of some uncertainty factors can lead to poorly comparable granulometric datasets. Other important factor leading to the aforementioned effect is the inadequate chemical pretreatment procedures which are often overlooked, but are capable to basically affect the results. In this study we examine a few past and recent sediment types from different geomorphological environments from the Carpathian Basin: lake and fluvial sediments, paleosols and loess. Our aim is to review and create a reliable methodology for laser diffraction particle size analysis and optical particle shape investigations. We compare widely used pretreatment methods -which can be found in the literature- with each other. We are also taking into account that different sediment types need different pretreatment methods. We can state that the duration of chemical pretreatment can affect the optical properties (color), the texture and the mineral composition of the sediments, as well as the size and shape of mineral particles in the samples. The changes in these significant parameters can mislead the researcher&amp;#8217;s main objectives. The study is supported by the &amp;#218;NKP-19-3 New National Excellence Program of the Ministry for Innovation and Technology. Support of the National Research, Development and Innovation Office NKFIH K120620 is gratefully acknowledged.&lt;/p&gt;

scholarly journals Similarities and Differences of Small Bay-Bars of the North-Eastern Part of the Black Sea

2021 ◽  
Author(s):  
V. V. Krylenko ◽  
Yu. N. Goryachkin ◽  
R. D. Kosyan ◽  
M. V. Krylenko ◽  
L. V. Kharitonova ◽  
...  
Keyword(s):  
Black Sea ◽  
Laser Scanning ◽  
Dynamic Equilibrium ◽  
Particle Size Analysis ◽  
The Black Sea ◽  
Size Analysis ◽  
Self Healing ◽  
Crimean Peninsula ◽  
Black Sea Region ◽  
Natural Objects

The accumulative coastal forms of the Azov-Black Sea region are a valuable recreational resource experiencing an increasing anthropogenic impact. The paper analizes the current state of two similar natural objects: small bay-bars of the Lake Bogaily (Crimean Peninsula) and the Lake Solenoe (Taman Peninsula). The materials of long-term monitoring observations were used (echo-sounding measurements, geodetic and aerial photography, air laser scanning, particle size analysis of sediments, etc.). The data of satellite imagery, materials of mathematical modeling of hydrological and lithodynamics processes, literary and archival sources were used. Both common and regional features of the development and structure of accumulative forms have been identified. The common features include similar transverse surface profiles (excluding anthropogenic transformation) and a set of natural factors. The most important differences are the genesis and composition of the bedrocks and accumulative deposits. These parameters determine the current sediment budget, configuration of the beach and underwater slope, and the relief dynamics. Displacement of accumulative bodies toward the lagoons is observed, the rate of this displacement depends on retreat of the adjacent bedrock coasts. The morphological and dynamical features of these bay-bars have not changed fundamentally over the past decades. The bay-bar of the Lake Solenoe has undergone a greater technogenic transformation in comparison with the bay-bar of the Lake Bogaily. However, the self-healing processes confirming that the geosystem has not been brought out of the dynamic equilibrium are clearly in evidence. It is concluded that the considered natural objects do not require construction of coast protection structures.

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