scholarly journals Assessment of reverse gun taylor cylinder experimental configuration

2021 ◽  
Vol 149 ◽  
pp. 103772
Author(s):  
Nicholas R. Scott ◽  
Matthew D. Nelms ◽  
Nathan R. Barton
Keyword(s):  
Experimental Configuration

scholarly journals Comparison of Buoy-Mounted and Bottom-Moored ADCP Performance at Gray’s Reef

2007 ◽  
Vol 24 (2) ◽  
pp. 270-284 ◽  
Author(s):  
Harvey E. Seim ◽  
Catherine R. Edwards
Keyword(s):  
High Frequency ◽  
Major Axis ◽  
National Data ◽  
Noise Floor ◽  
The North ◽  
Experimental Configuration ◽  
Adcp Measurements ◽  
Adcp Data ◽  
Adcp Observations ◽  
East West

Abstract Simultaneous ADCP profile measurements are compared over a 2-month period in late 2003. One set of measurements comes from a National Data Buoy Center (NDBC) buoy-mounted ADCP, the other from a bottom-mounted, upward-looking ADCP moored roughly 500 m from the buoy. The study was undertaken to evaluate the proficiency of an experimental configuration by NDBC; unfortunately, the ADCP was not optimally configured. The higher temporally and vertically resolved bottom-mounted ADCP data are interpolated in time and depth to match the buoy-mounted ADCP measurements. It is found that the two ADCP measurements are significantly different. The buoy-mounted measurements are affected by high-frequency (<10 h period) noise that is vertically coherent throughout the profiles. This noise results in autospectra that are essentially white, unlike the classic red spectra formed from the bottom-mounted ADCP observations. The spectra imply a practical noise floor of 0.045 m s−1 for the buoy-mounted system. Contamination by surface waves is the likely cause of this problem. At tidal frequencies the buoy-mounted system underestimates major axis tidal current magnitude by 10%–40%; interference from the buoy chain and/or fish or plankton are considered the most likely cause of the bias. The subtidal velocity field (periods greater than 40 h) is only partially captured; the correlation coefficient for the east–west current is 0.49 and for the north–south current is 0.64.

scholarly journals Simple Method for Estimating the Contribution of Neighbouring n-beam Interactions to Two-beam Structure Factors

1988 ◽  
Vol 41 (3) ◽  
pp. 469
Author(s):  
HJ Juretschke ◽  
HK Wagenfeld
Keyword(s):  
Experimental Determination ◽  
Structure Factor ◽  
Beam Structure ◽  
Simple Method ◽  
Experimental Configuration ◽  
Structure Factors ◽  
Special Cases ◽  
Better Than

Unless special precautions are taken, the experimental determination of two-beam structure factors to better than 1 % may include contributions from neighbouring n-beam interactions. In any particular experimental configuration, corrections for such contributions are easily carried out using the modified two-beam structure factor formalism developed recently (Juretschke 1984), once the full indexing of the pertinent n-beam interactions is known. The method is illustrated for both weak and strong primary reflections and its applicability in special cases, as well as for less than perfect crystals, is discussed.

Surface permeability tests: experiments and modelling for estimating effective permeability

2010 ◽  
Vol 466 (2122) ◽  
pp. 2819-2846 ◽  
Author(s):  
A. P. S. Selvadurai ◽  
P. A. Selvadurai
Keyword(s):  
Flow Rate ◽  
Effective Permeability ◽  
Flat Surface ◽  
Computational Techniques ◽  
Near Surface ◽  
Permeability Characteristics ◽  
Constant Flow Rate ◽  
Experimental Configuration ◽  
Surface Permeability ◽  
Indiana Limestone

This paper presents a technique for determining the near surface permeability of geomaterials and involves the application of a uniform flow rate to an open central region of a sealed annular patch on an otherwise unsealed flat surface. Darcy’s flow is established during attainment of a steady pressure at a constant flow rate. This paper describes the experimental configuration and its theoretical analysis via mathematical and computational techniques. The methods are applied to investigate the surface permeability characteristics of a cuboidal block of Indiana limestone measuring 508 mm. An inverse analysis procedure is used to estimate the permeability characteristics at the interior of the Indiana limestone block. The resulting spatial distribution of permeability is used to estimate the effective permeability of the tested block.

scholarly journals Computational framework chinook for angle-resolved photoemission spectroscopy

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Ryan P. Day ◽  
Berend Zwartsenberg ◽  
Ilya S. Elfimov ◽  
Andrea Damascelli
Keyword(s):  
Photoemission Spectroscopy ◽  
Spin Projection ◽  
Matrix Elements ◽  
Orbital Structure ◽  
Computational Framework ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Experimental Configuration ◽  
Numerical Software ◽  
The Matrix ◽  
Experimental Geometry

Abstract We have developed the numerical software package chinook for the simulation of photoemission matrix elements. This quantity encodes a depth of information regarding the orbital structure of the underlying wavefunctions from which photoemission occurs. Extraction of this information is often nontrivial, owing to the influence of the experimental geometry and photoelectron interference, precluding straightforward solutions. The chinook code has been designed to simulate and predict the ARPES intensity measured for arbitrary experimental configuration, including photon-energy, polarization, and spin-projection, as well as consideration of both surface-projected slab and bulk models. This framework then facilitates an efficient interpretation of the ARPES, allowing for a deeper understanding of the electronic structure in addition to the design of new experiments which leverage the matrix element effects towards the objective of selective photoemission from states of particular interest.

scholarly journals High-efficiency ultra-precision comparator for d-spacing mapping measurement of silicon

2020 ◽  
Vol 27 (3) ◽  
pp. 577-582 ◽  
Author(s):  
Junliang Yang ◽  
Tang Li ◽  
Ye Zhu ◽  
Xiaowei Zhang ◽  
Atsushi Waseda ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
High Efficiency ◽  
Photon Counting ◽  
Pencil Beam ◽  
Systematic Deviation ◽  
One Dimensional ◽  
X Ray ◽  
Experimental Configuration ◽  
Ultra Precision ◽  
Position Sensitive

This article describes a high-efficiency experimental configuration for a self-referenced lattice comparator with a `brush beam' of synchrotron radiation from a bending magnet and two linear position-sensitive photon-counting-type X-ray detectors. The efficiency is more than ten times greater compared with the `pencil-beam' configuration and a pair of zero-dimensional detectors. A solution for correcting the systematic deviation of d-spacing measurements caused by the horizontal non-uniformity of the brush beam is provided. Also, the use of photon-counting-type one-dimensional detectors not only improves the spatial resolution of the measurements remarkably but can also adjust the sample's attitude angles easily.

scholarly journals Influence of the Instructions on the Performance and Establishment of Memorization Strategies in Space Judgments

2006 ◽  
Vol 9 (2) ◽  
pp. 312-320 ◽  
Author(s):  
Alessandra Ackel Rodrigues ◽  
Susi Lippi Marques
Keyword(s):  
Graduate Students ◽  
Power Function ◽  
Mental Representation ◽  
Spatial Information ◽  
Internal Representation ◽  
Space Perception ◽  
Physical Space ◽  
Visual Space ◽  
Experimental Conditions ◽  
Experimental Configuration

Studies of visual space perception have been assuming that people have an internal representation of the physical space that surrounds them. A variety of psychophysical procedures has been used in an attempt to measure the properties of visual space. The goal of the present study was to evaluate the accuracy of the mental representation and the strategies adopted to acquire and retain visuo-spatial information of a configuration as a function of two types of instructions. Thirty-eight undergraduate and graduate students participated in the study and were distributed in perceptive and mnemonic experimental conditions. The effect of the instructions (intentional and incidental) on the representation of the distances among the objects of the scene was estimated using exponents of power function, based on the reproduction of the distances among the stimuli of the scene. The results revealed that judgments made under intentional instructions were more frequently based on strategies related to the location of the stimuli, whereas judgments originating from incidental instructions were based on strategies related to the name of the stimuli. It was observed that the intentional instruction facilitated a more accurate mental representation of the observed experimental configuration, enhancing participants' performance.

scholarly journals Substrate Integrated Waveguide Cross-Coupling Filter with Multilayer Hexagonal Cavity

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
B. Wu ◽  
Z. Q. Xu ◽  
J. X. Liao
Keyword(s):  
Low Temperature ◽  
Cross Coupling ◽  
Experimental Results ◽  
Substrate Integrated Waveguide ◽  
Central Frequency ◽  
Experimental Configuration ◽  
And Performance ◽  
Multilayer Substrate

Hexagonal cavities and their applications to multilayer substrate integrated waveguide (SIW) filters are presented. The hexagonal SIW cavity which can combine flexibility of rectangular one and performance of circular one is convenient for bandpass filter’s design. Three types of experimental configuration with the same central frequency of 10 GHz and bandwidth of 6%, including three-order and four-order cross-coupling topologies, are constructed and fabricated based on low temperature cofired ceramic (LTCC) technology. Both theoretical and experimental results are presented.

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