Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 25 for “"grain size distributions"”.
-
Grain size distributions of various materials in an abrasion mill
Wet abrasion of sand-sized quartz and orthoclase in polyethylene bottles for 912 hours showed that abrasion of fine material is practically negligible, in agreement with Kuenen (1959). The size distributions of the sand. sized quartz and orthoclase remained unchanged. The size distributions of …
-
Electrochemical kinetics of thin film vanadium pentoxide cathodes for lithium batteries
… resulting in films with different morphologies, grain size distributions, and orientations. Key findings included (1) grain size distributions largely did not affect the current rate performance of the cathodes. Rather, the film orientation and the ability to undergo rapid phase transformation …
-
Advanced methods for analysing and modelling multivariate palaeoclimatic time series
… For an example of trace element abundances and grain-size distributions obtained near the Cape Roberts (Eastern Antarctica), it is shown that the variability of the dimensions of the investigated data sets clearly correlates with the Oligocene/Miocene transition about 24 million years before …
-
A Stratigraphic and Depositional Interpretation of a Sand Quarry in Middle Georgia
… structures. Sediment samples were examined for grain-size distributions and other sediment textures.</p>
-
Incorporating Grain Size Effects in Taylor Crystal Plasticity
<p>A method to incorporate grain size effects into crystal plasticity is presented. The classical Hall-Petch equation inaccurately predicts the macroscopic yield strength for materials with non-equiaxed grains or materials that contain unequal grain size distributions. These deficiencies can be …
-
Integrated computational and experimental framework for the assessment of railroad ballast life-cycle behavior
Ballast, typically comprising large sized aggregate particles with uniform gradation, is an essential layer in the railroad track substructure. Functions of ballast include facilitating load distribution and drainage, maintaining track geometry and track stability, and providing track resilience …
-
The fracture toughness of ultrafine WC-Co Alloys
… of a series of cemented carbides having carbide grain sizes between 0.35f.Lm and 4f.Lm, cobalt contents ranging from 6 to 15wt%, and vanadium carbide contents from 0 to 0.8wt%. A series of twenty-four ultrafine WC-Co alloys were sintered from powders produced through three different production …
-
Predicting adverse geology and tunnel responses utilizing tunnel-ground interaction data with machine learning techniques
… 1) clay-sand mixed face conditions, 2) grain size distributions, and 3) TBM clogging potential. The EPBM operational data and geotechnical data collected from Northgate Link extension tunneling project in Seattle were used for this study. Machine learning classifiers and regressors were …
-
Stratigraphy, magnetic susceptibility, and mineralogy of loess-paleosol sequences in southwestern Illinois and eastern Missouri
… susceptibility (MS) zones, controlled by silt-size magnetite concentrations, have been delineated within oxidized, C horizon Peoria and Loveland Silts along the Illinois and Mississippi Valleys. Lower Peoria and lower Loveland Silts (MS = 55-80 $\times\ 10\sp{-5}$ SI) and Roxana Silt (MS = …
-
From Representative Period Selection to Process‐Based Sediment Dynamics
… flux (ASF) approach was developed to infer grain-size distributions from modelled sediment fluxes; it reproduces observed patterns in the dynamic channels and flats, but skill decreases offshore, where relict sediments dominate. Finally, the influence of storm directionality was assessed. …
-
Spatial Relationships Between Potential Bioavailable Organic Carbon and Sediment Grain Size at a Chlorinated Solvent-Contaminated Site
… evaluated. Exploring relationships between the grain size of aquifer sediment PBOC may help to determine the feasibility of natural attenuation as a long-term remediation strategy at chlorinated ethene-contaminated sites. Because hydraulic conductivity is directly related to aquifer sediment …
-
HYDRAULIC PERFORMANCE OF GEOSYNTHETIC LINERS IN TAILINGS STORAGE FACILITIES
… tailings. The effect of hole shapes, hole sizes, GMB thicknesses, tailings thicknesses, tailings homogeneity, applied stresses, water heads, subgrade grain-size distributions and surface irregularity, and a geotextile filtration layer on leakage and piping through the GMB defect are …
-
Computer vision and texture analysis for characterization of X-ray images of rocks
… map. The resulting GLCM-statistics are linked to grain-size distributions, (an)isotropic grain arrangement, and mineralogical heterogeneity in Sandstones. Analysis by GLCM alleviates user-biases and allows automation of micro-CT analyses using grayscale statistical measures. Third, a novel …
-
Deflation basin stratigraphy: southwestern North Dakota
… Computer analyses were used to characterize grain-size distributions and to correlate texture and mineralogy by cross-association. </p><p>The results of the study verified a similar depositional sequence in the basin sediments. The sediments exhibited two dominant colors, olive and brown. The …
-
Characterization of Pre and Post Re-Naturalized Surface Water/Groundwater Exchange, Jocko River, Flathead Indian Reservation, Montana
… pre- and postrestoration water table position. Grain size analyses, falling head slug tests, seepage runs, mini-piezometers and streambed temperature profiles were used to define the direction and magnitudes of channel-groundwater exchange. Study results show the upper 6400 ft of the river in …
-
Characterization of Pre and Post Re-Naturalized Surface Water/Groundwater Exchange, Jocko River, Flathead Indian Reservation, Montana
… pre- and postrestoration water table position. Grain size analyses, falling head slug tests, seepage runs, mini-piezometers and streambed temperature profiles were used to define the direction and magnitudes of channel-groundwater exchange. Study results show the upper 6400 ft of the river in …
-
Patch reefs off Bermuda
… the sediment. From the reef top lagoonward, mean grain size generally decreases (with certain anomalies explainable by the patch reef model of sediment dispersion), sorting progresses from poor to very poor, and skewness becomes relatively higher (due to winnowing of fine particles and addition of …
-
Remote estimation of grain size distribution and simulating grain size effects on debris-flow rheology and post-fire variability of transport by dry ravel
The size distribution of granular material influences the length scale of sediment transport by dry ravel and debris flows. Variability in erosion rates and the grain size distribution of material delivered to channels has been observed due to an increase in the annual areal extent of wildfire in …
-
Effect of grading and grain size on the friction characteristics of a sand/geotextile inteface
… interacting with sands of different grading, grain size distributions and grain shapes namely; Cape Flats, Klipheuwel and Munich sands. The respective responses were primarily presented in terms of shear stress/horizontal displacement and pUll-out resistance/front displacement relationships; …
-
Improving Turbidity-Based Estimates of Suspended Sediment Concentrations and Loads
… the measured physical properties, which included grain-size distributions, specific surface-area, and organic carbon, in turbidity-based SSC estimation models reduces unexplained variance. Further, the use of hydrologic variables, which were measured remotely and on the same temporal scale as …
Page 1 of 2