scholarly journals An instrumented sample holder for time-lapse microtomography measurements of snow under advective airflow

2014 ◽  
Vol 3 (2) ◽  
pp. 179-185 ◽  
Author(s):  
P. P. Ebner ◽  
S. A. Grimm ◽  
M. Schneebeli ◽  
A. Steinfeld
Keyword(s):  
Structural Changes ◽  
Time Lapse ◽  
Temperature Gradients ◽  
Sample Holder ◽  
Experimental Characterization ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations ◽  
Snow Samples

Abstract. An instrumented sample holder was developed for time-lapse microtomography of snow samples to enable in situ nondestructive spatial and temporal measurements under controlled advective airflows, temperature gradients, and air humidities. The design was aided by computational fluid dynamics simulations to evaluate the airflow uniformity across the snow sample. Morphological and mass transport properties were evaluated during a 4-day test run. This instrument allows the experimental characterization of metamorphism of snow undergoing structural changes with time.

scholarly journals An instrumented sample holder for time-lapse micro-tomography measurements of snow under advective airflow

2014 ◽  
Vol 4 (1) ◽  
pp. 353-373
Author(s):  
P. P. Ebner ◽  
S. A. Grimm ◽  
M. Schneebeli ◽  
A. Steinfeld
Keyword(s):  
Structural Changes ◽  
Time Lapse ◽  
Sample Holder ◽  
Experimental Characterization ◽  
Computational Fluid Dynamics Simulations ◽  
Micro Tomography ◽  
Dynamics Simulations ◽  
Snow Samples

Abstract. An instrumented sample holder was developed for time-lapse micro-tomography of snow samples to enable in-situ nondestructive spatial and temporal measurements under controlled advective airflows, temperature gradients, and air humidities. The design was aided by computational fluid dynamics simulations to evaluate the airflow uniformity across the snow sample. Morphological and mass transport properties were evaluated during a 4 day test run. This instrument allows the experimental characterization of metamorphism of snow undergoing structural changes with time.

Density-Functional Theory Molecular Dynamics Simulations and Experimental Characterization of a-Al2O3/SiGe Interfaces

2015 ◽  
Vol 7 (47) ◽  
pp. 26275-26283 ◽  
Author(s):  
Evgueni Chagarov ◽  
Kasra Sardashti ◽  
Tobin Kaufman-Osborn ◽  
Shailesh Madisetti ◽  
Serge Oktyabrsky ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Molecular Dynamics Simulations ◽  
Density Functional ◽  
Experimental Characterization ◽  
Functional Theory ◽  
Dynamics Simulations

scholarly journals High-temperature (1500 K) reciprocal space mapping on a laboratory X-ray diffractometer

2007 ◽  
Vol 40 (2) ◽  
pp. 332-337 ◽  
Author(s):  
R. Guinebretière ◽  
A. Boulle ◽  
R. Bachelet ◽  
O. Masson ◽  
P. Thomas
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Reciprocal Space ◽  
Primary Beam ◽  
Sample Holder ◽  
Reciprocal Space Mapping ◽  
X Ray ◽  
Translation Stage

A laboratory X-ray diffractometer devoted to thein situcharacterization of the microstructure of epitaxic thin films at temperatures up to 1500 K has been developed. The sample holder was built using refractory materials, and a high-accuracy translation stage allows correction of the dilatation of both the sample and the sample holder. The samples are oriented with respect to the primary beam with two orthogonal rotations allowing the registration of symmetric as well as asymmetric reciprocal space maps (RSMs). The association of a monochromatic primary beam and a position-sensitive detector allows the measurement of RSMs in a few minutes for single crystals and in a few hours for imperfect epitaxic thin films. A detailed description of the setup is given and its potential is illustrated by high-temperature RSM experiments performed on yttria-doped zirconia epitaxic thin films grown on sapphire substrates.

scholarly journals In Situ Compensation Method for Precise Integral SQUID Magnetometry of Miniscule Biological, Chemical, and Pow-der Specimens Requiring the Use of Capsules

2022 ◽  
Author(s):  
Katarzyna Gas ◽  
Maciej Sawicki
Keyword(s):  
Reduction Method ◽  
Experimental Methodology ◽  
Sample Holder ◽  
Squid Magnetometry ◽  
In Situ Reduction ◽  
Magnetic Characterization ◽  
Data Reduction Method ◽  
Alignment Errors

Steadily growing interest in magnetic characterization of organic compounds for therapeutic purposes or of other irregularly shaped specimens calls for refinements of experimental methodology to satisfy experimental challenges. Encapsulation in capsules remains the method of choice, but its applicability in precise magnetometry is limited. This is particularly true for minute specimens in the single milligram range as they are outweighed by the capsules and are subject to large alignment errors. We present here a completely new experimental methodology that permits 30-fold in situ reduction of the signal of capsules by substantially restoring the symmetry of the sample holder that is otherwise broken by the presence of the capsule. In practical terms it means that the standard 30 mg capsule is seen by the magnetometer as approximately a 1 mg object, effectively opening the window for precise magnetometry of single milligram specimens. The method is shown to work down to 1.8 K and in the whole range of the magnetic fields. The method is demonstrated and validated using the reciprocal space option of MPMS-SQUID magnetometers; however, it can be easily incorporated in any magnetometer that can accommodate straw sample holders (i.e., the VSM-SQUID). Importantly, the improved sensitivity is accomplished relying only on the standard accessories and data reduction method provided by the SQUID manufacturer, eliminating the need for elaborate raw data manipulations.

scholarly journals Form and function in hillslope hydrology: in situ imaging and characterization of flow-relevant structures

2017 ◽  
Vol 21 (7) ◽  
pp. 3749-3775 ◽  
Author(s):  
Conrad Jackisch ◽  
Lisa Angermann ◽  
Niklas Allroggen ◽  
Matthias Sprenger ◽  
Theresa Blume ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Hydraulic Conductivity ◽  
Soil Water ◽  
Time Lapse ◽  
Saturated Hydraulic Conductivity ◽  
Form And Function ◽  
And Function ◽  
Hillslope Scale

Abstract. The study deals with the identification and characterization of rapid subsurface flow structures through pedo- and geo-physical measurements and irrigation experiments at the point, plot and hillslope scale. Our investigation of flow-relevant structures and hydrological responses refers to the general interplay of form and function, respectively. To obtain a holistic picture of the subsurface, a large set of different laboratory, exploratory and experimental methods was used at the different scales. For exploration these methods included drilled soil core profiles, in situ measurements of infiltration capacity and saturated hydraulic conductivity, and laboratory analyses of soil water retention and saturated hydraulic conductivity. The irrigation experiments at the plot scale were monitored through a combination of dye tracer, salt tracer, soil moisture dynamics, and 3-D time-lapse ground penetrating radar (GPR) methods. At the hillslope scale the subsurface was explored by a 3-D GPR survey. A natural storm event and an irrigation experiment were monitored by a dense network of soil moisture observations and a cascade of 2-D time-lapse GPR trenches. We show that the shift between activated and non-activated state of the flow paths is needed to distinguish structures from overall heterogeneity. Pedo-physical analyses of point-scale samples are the basis for sub-scale structure inference. At the plot and hillslope scale 3-D and 2-D time-lapse GPR applications are successfully employed as non-invasive means to image subsurface response patterns and to identify flow-relevant paths. Tracer recovery and soil water responses from irrigation experiments deliver a consistent estimate of response velocities. The combined observation of form and function under active conditions provides the means to localize and characterize the structures (this study) and the hydrological processes (companion study Angermann et al., 2017, this issue).

In situ characterization of structural changes and the fraction of aligned carbon nanotube networks produced by stretching

Carbon ◽  
2012 ◽  
Vol 50 (10) ◽  
pp. 3859-3867 ◽  
Author(s):  
Shu Li ◽  
Jin Gyu Park ◽  
Zhiyong Liang ◽  
Theo Siegrist ◽  
Tao Liu ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Structural Changes ◽  
In Situ Characterization ◽  
Carbon Nanotube Networks

In-Situ X-Ray Characterization of LiMn2O4: A Comparison of Structural and Electrochemical Behavior

1997 ◽  
Vol 496 ◽  
Author(s):  
Mark A. Rodriguez ◽  
David Ingersoll ◽  
Daniel H. Doughty
Keyword(s):  
Crystal Structure ◽  
Structural Changes ◽  
Phase Changes ◽  
X Ray ◽  
In Situ Xrd ◽  
Electrochemical Cycling ◽  
Kinetic Effects ◽  
Carbon Anodes

ABSTRACTLixMn2O4 materials are of considerable interest in battery research and development. The crystal structure of this material can significantly affect the electrochemical performance. The ability to monitor the changes of the crystal structure during use, that is during electrochemical cycling, would prove useful to verify these types of structural changes. We report in-situ XRD measurements of LiMn2O4 cathodes with the use of an electrochemical cell designed for in-situ X-ray analysis. Cells prepared using this cell design allow investigation of the changes in the LiMn2O4 structure during charge and discharge. We describe the variation in lattice parameters along the voltage plateaus and consider the structural changes in terms of the electrochemical results on each cell. Kinetic effects of LiMn2O4 phase changes are also addressed. Applications of the in-situ cell to other compounds such as LiCoO2 cathodes and carbon anodes are presented as well.

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