scholarly journals Froude supercritical flow processes and sedimentary structures: New insights from experiments with a wide range of grain sizes

Sedimentology ◽  
2020 ◽  
Author(s):  
Kenya Ono ◽  
Piret Plink‐Björklund ◽  
Joris T. Eggenhuisen ◽  
Matthieu J. B. Cartigny
Keyword(s):  
Supercritical Flow ◽  
Grain Sizes ◽  
Sedimentary Structures ◽  
Wide Range ◽  
Flow Processes

The Processing of Ultrafine-Grained Materials Using High-Pressure Torsion

2007 ◽  
Vol 558-559 ◽  
pp. 1283-1294 ◽  
Author(s):  
Cheng Xu ◽  
Z. Horita ◽  
Terence G. Langdon
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
High Pressure ◽  
High Pressure Torsion ◽  
Metallic Materials ◽  
Grain Sizes ◽  
Ultrafine Grained ◽  
Wide Range ◽  
Ultrafine Grained Materials ◽  
Thin Disks

It is now well-established that processing through the application of severe plastic deformation (SPD) leads to a significant reduction in the grain size of a wide range of metallic materials. This paper examines the fabrication of ultrafine-grained materials using high-pressure torsion (HPT) where this process is attractive because it leads to exceptional grain refinement with grain sizes that often lie in the nanometer or submicrometer ranges. Two aspects of HPT are examined. First, processing by HPT is usually confined to samples in the form of very thin disks but recent experiments demonstrate the potential for extending HPT also to bulk samples. Second, since the strains imposed in HPT vary with the distance from the center of the disk, it is important to examine the development of inhomogeneities in disk samples processed by HPT.

Effect of surface area of grain boundaries on stress relaxation behavior in pure copper over wide range of grain sizes

2020 ◽  
Vol 794 ◽  
pp. 139585
Author(s):  
Yurina Suzuki ◽  
Kota Ueno ◽  
Kodai Murasawa ◽  
Yoshinori Kusuda ◽  
Masato Takamura ◽  
...  
Keyword(s):  
Stress Relaxation ◽  
Grain Boundaries ◽  
Surface Area ◽  
Pure Copper ◽  
Relaxation Behavior ◽  
Stress Relaxation Behavior ◽  
Grain Sizes ◽  
Wide Range ◽  
Effect Of Surface

Environmental magnetism as a stream sediment tracer: an interpretation of the methodology and some case studies

Soil Research ◽  
1998 ◽  
Vol 36 (1) ◽  
pp. 167 ◽  
Author(s):  
R. H. Crockford ◽  
P. M. Fleming
Keyword(s):  
Grain Size ◽  
Case Studies ◽  
Environmental Magnetism ◽  
Extensive Discussion ◽  
Remanent Magnetisation ◽  
Grain Sizes ◽  
South Wales ◽  
Wide Range ◽  
River Confluences ◽  
The Difference

A comprehensive sediment sampling program was undertaken in the upper Molonglo catchment in south-eastern New South Wales to determine if mineral magnetics could be used to estimate sidestream contribution at river confluences in this environment. Some 12 confluences were examined over 1400 km 2 in 2 major basins and over 2 contrasting geological types. Sediment samples were divided into 7 size classes and the following magnetic properties measured: magnetic susceptibility at 2 frequencies, isothermal remanent magnetisation at 3 flux densities, and anhysteristic remanent magnetisation. The sidestream inputs were calculated for each particle size class from the range of magnetic parameters. Significant discrepancies and differences appeared in the resultant sidestream inputs, and this paper outlines the conclusions as to the reliability of the different analytical procedures. It is shown that both the concentration and magnetic grain size of ferrimagnetic minerals in the sediments must be taken into account. Where the difference in magnetic grain size between the upstream and sidestream sediments is small, the use of parameter crossplots or bulked magnetic ratios is generally not appropriate. The use of mass (concentration) magnetic values may be better. The difference in the demands of the crossplots and mass values methods is that crossplots require a wide range of mass magnetic concentrations in each branch, with the upstream and sidestream sediments having different magnetic grain sizes, whereas the mass values procedure does best with a very limited (but different) range of concentrations at the upstream and sidestream branches, but similar magnetic grain sizes. This paper provides an extensive discussion of the estimation technique using different parameter combinations, and uses 3 contrasting confluences as case studies.

scholarly journals Morphodynamics and sedimentary structures of bedforms under supercritical-flow conditions: New insights from flume experiments

Sedimentology ◽  
2013 ◽  
Vol 61 (3) ◽  
pp. 712-748 ◽  
Author(s):  
Matthieu J.B. Cartigny ◽  
Dario Ventra ◽  
George Postma ◽  
Jan H. van Den Berg
Keyword(s):  
Flow Conditions ◽  
Flume Experiments ◽  
Supercritical Flow ◽  
Sedimentary Structures

REPLY BY AUTHORS TO DISCUSSION BY W. T. HIGDON

Geophysics ◽  
1963 ◽  
Vol 28 (2) ◽  
pp. 310-313 ◽  
Author(s):  
V. V. Jagannadha Sarma ◽  
V. Bhaskara Rao
Keyword(s):  
Electrical Resistivity ◽  
The Other ◽  
Grain Sizes ◽  
Introductory Statement ◽  
Three Samples ◽  
Wide Range ◽  
Geological Formation ◽  
The Subject ◽  
Two Parameters ◽  
Broad Generalization

The introductory statement that “The electrical resistivity of a geological formation is a function of … (1) the amount of moisture and consequently of porosity; (2) salinity of the moisture; and (3) grain size of the formation” is intended as a broad generalization to include possible parameters affecting resistivity variations. Of these three parameters, only the influence of the amount of moisture on the electrical resistivity variations is the subject of the results reported. At the same time, the possible effects of the other two parameters have been taken into consideration in the control of experiments and discussion of results. Thus, at least three samples (2, 3, and 4) of known average grain sizes of 1.5, 0.75, and 0.37 mm are treated with five samples of water with a wide range of known salinities. By such a distribution, it is ensured that the electrical resistivity variations of the sample in a given run are due only to the varying water content. Corrections to the data required for representation are thus avoided.

scholarly journals Store Elements LabView-based Energy-flow Models Developmnet and Implementation in HVAC systems

2015 ◽  
Vol 2 (1-2.) ◽  
Author(s):  
Csaba Szász
Keyword(s):  
Virtual Instrument ◽  
Energy Flow ◽  
Model Development ◽  
Measurement Data ◽  
Hvac Systems ◽  
Hot Water ◽  
Water Tank ◽  
Software Modeling ◽  
Wide Range ◽  
Flow Processes

It is well known that store elements such as liquid tanks, water reservoirs, or gas containers, are basic elements in heating, ventilation and air conditioning (HVAC) systems development and implementation. In a wide range of applications they serve as efficient energy storage elements by capturing heat energy amount in hot water form. This paper presents a LabView graphical software-based energy-flow model development for store elements in HVAC systems. In the first research steps the mathematical background describing the energy-flow processes in the considered store element (water tank) it is presented and discussed. Then an original software model has been designed and implemented to simulate the ongoing energy-flow processes. The result of the above mentioned research efforts is a powerful and versatile software toolkit (virtual instrument) well suitable to modeling and simulate complex energy-flow processes in HVAC systems embedding various types of store elements. Beside the elaborated mathematical model concrete software simulation examples and measurement data are also provided in the paper. Not at least, the proposed original model offers a feasible solution for future developments and research in HVAC systems software modeling and simulation purposes.

Effect of Low-Temperature Aging on Thermally-Induced Phase Transformation of NiTi Wire with a Wide Range of Grain Sizes

2021 ◽  
Vol 1042 ◽  
pp. 9-16
Author(s):  
Zhi Hao Zhao ◽  
Jian Ping Lin ◽  
Jun Ying Min ◽  
Yong Hou ◽  
Bo Sun
Keyword(s):  
Grain Size ◽  
Phase Transformation ◽  
Low Temperature ◽  
Thermally Induced ◽  
Grain Sizes ◽  
Average Grain Size ◽  
Wide Range ◽  
Low Temperature Aging ◽  
Niti Wires ◽  
Temperature Aging

Thermally-induced phase transformation (PT) is of significance and value to the application of NiTi alloy components. Low-temperature aging (LTA) treatment was used to alter PT characteristics of NiTi alloys avoiding undesirable grain growth. Effect of LTA on PT of NiTi wires with a wide range of grain sizes from 34 nm to 8021 nm was investigated in this study. As the average grain size varies from 34 to 217 nm, the temperature of the B2↔R transformation increase as a result of LTA, and the increasing effect is more obvious at a larger grain size. For NiTi alloys with average grain sizes ranging from 523 to 1106 nm, transformation sequence changes from B2↔B19' to B2↔R due to LTA. For the sample with an average grain size of 2190 nm, the B2↔B19' transformation is replaced by B2↔R←B19' after LTA. When the average grain size is larger than 2190 nm, transformation sequence changes from B2↔B19' to B2↔R↔B19' after LTA. Transmission emission microscope observations reveal that the above-mentioned PT behavior correlates with the coupled effect of grain size and precipitation. The precipitation of Ni4Ti3 in the grains with a size smaller than ~150 nm is inhibited after LTA, the temperature of B2→R of samples with average GS smaller than ~150 nm still is elevated due to the inhomogeneous grain size of NiTi wires.

Elimination of membrane compliance in undrained triaxial testing. I. Measurement and evaluation

1993 ◽  
Vol 30 (5) ◽  
pp. 727-738 ◽  
Author(s):  
P.G. Nicholson ◽  
R.B. Seed ◽  
H.A. Anwar
Keyword(s):  
Grain Size ◽  
Test Results ◽  
Factors Affecting ◽  
Grain Sizes ◽  
Wide Range ◽  
Specimen Density ◽  
Thin Membranes ◽  
Alternative Approaches ◽  
Measurement And Evaluation ◽  
Material Grain Size

Several alternative approaches have been suggested for evaluation and correction of the testing errors caused by membrane compliance. The degree to which membrane compliance may affect the results of an undrained test is a function of the soil grain size and overall geometry of the test specimen, as well as specimen density and range of effective confining stresses during a given test. Membrane-compliance effects may be negligible for fine sands and silts tested in conventional 71 mm diameter samples, since even very thin membranes cannot penetrate significantly into the small surficial voids. For medium to coarse sands and gravels, however, membrane-compliance effects may have a significant influence on test results. The scope of this paper is threefold: firstly, to review, examine, and evaluate the variety of methods to measure and characterize membrane compliance; secondly, to develop an improved understanding of the factors affecting membrane compliance; and thirdly, to provide an enhanced, updated, and expanded correlation for estimating membrane compliance characteristics as a function of material grain size for a range of soil types, including a wide range of gradation types and representative grain sizes from silts through gravels. Key words : membrane, penetration, compliance, undrained testing, triaxial, measurement, evaluation.

Supercritical‐flow processes and depositional products: Introduction to thematic issue

Sedimentology ◽  
2021 ◽  
Author(s):  
Arnoud Slootman ◽  
Dario Ventra ◽  
Matthieu Cartigny ◽  
Alexandre Normandeau ◽  
Stephen Hubbard
Keyword(s):  
Thematic Issue ◽  
Supercritical Flow ◽  
Flow Processes
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