scholarly journals Best practices for operando depth-resolving battery experiments

2020 ◽  
Vol 53 (1) ◽  
pp. 133-139 ◽  
Author(s):  
Hao Liu ◽  
Zhuo Li ◽  
Antonin Grenier ◽  
Gabrielle E. Kamm ◽  
Liang Yin ◽  
...  
Keyword(s):  
Best Practices ◽  
Signal To Noise Ratio ◽  
Depth Profiling ◽  
State Of Charge ◽  
Cell Alignment ◽  
Spatially Resolved ◽  
Transmission Geometry ◽  
Transmission Measurements ◽  
Structural Insights ◽  
Accurate Quantification

Operando studies that probe how electrochemical reactions propagate through a battery provide valuable feedback for optimizing the electrode architecture and for mitigating reaction heterogeneity. Transmission-geometry depth-profiling measurements carried out with the beam directed parallel to the battery layers – in a radial geometry – can provide quantitative structural insights that resolve depth-dependent reaction heterogeneity which are not accessible from conventional transmission measurements that traverse all battery layers. However, these spatially resolved measurements are susceptible to aberrations that do not affect conventional perpendicular-beam studies. Key practical considerations that can impact the interpretation of synchrotron depth-profiling studies, which are related to the signal-to-noise ratio, cell alignment and lateral heterogeneity, are described. Strategies to enable accurate quantification of state of charge during rapid depth-profiling studies are presented.

scholarly journals A Sample Characterization Toolkit for Carbonate U-Pb Geochronology

2020 ◽  
Author(s):  
E. Troy Rasbury ◽  
Theodore M. Present ◽  
Paul Northrup ◽  
Ryan V. Tappero ◽  
Antonio Lanzirotti ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Reference Material ◽  
Best Practices ◽  
Sr Isotope ◽  
Turkana Basin ◽  
Spatially Resolved ◽  
Dolomite Sample ◽  
Three Samples ◽  
Sample Characterization ◽  
Barstow Formation

Abstract. Laser ablation U-Pb analyses of carbonate (LAcarb) samples has greatly expanded the potential for U-Pb dating to a variety of carbonate producing settings. Carbonates that were previously considered impossible to date using isotope dilution methods may preserve domains that are favorably interrogated when using spatially resolved laser ablation geochronology techniques. Work is ongoing to identify reference materials and to consider best practices for LAcarb. In this study we apply standard and emerging characterization toolsets on three natural samples with the dual goal of enhancing the study of carbonates and in establishing a new set of precisely characterized natural standards for LAcarb studies. We start with the existing carbonate reference material WC-1 from the Permian Reef Complex of Texas, building on the published description to offer a deeper look at U and fluids. We consider a tufa sample from the Miocene Barstow Formation of the Mojave Block, California, as a possible secondary calcite reference material due to its well-behaved U/Pb systematics. There are currently no natural dolomite standards. We present an unusual dolomite sample with very well-behaved U-Pb systematics from the Miocene of the Turkana Basin of Kenya as a possible dolomite reference material for LAcarb dating. In addition to using XRF mapping and spectroscopy to better understand U in these natural samples, we have analyzed multiple aliquots of each of them for 87Sr/86Sr. The Sr isotope compositions are reasonably homogeneous in all three samples, so that these could be used as Sr isotope standards as well. This combination could streamline split stream analyses of 87Sr/86Sr and U/Pb geochronology.

Contactless Spatially Resolved Measurement of Bulk Free-Carrier Lifetime in Silicon Ingots

1986 ◽  
Vol 69 ◽  
Author(s):  
S. M. Johnson ◽  
L. G. Johnson ◽  
R. Hemphill
Keyword(s):  
Spatial Dependence ◽  
Polycrystalline Silicon ◽  
Carrier Lifetime ◽  
Transient Absorption ◽  
Free Carrier ◽  
Large Area ◽  
Spatially Resolved ◽  
Probe Transmission ◽  
Transmission Measurements ◽  
Absorption Measurements

AbstractA contactless spatially resolved measurement of bulk free-carrier lifetime in polycrystalline silicon ingots was accomplished using optically modulated free-carrier infrared absorption. Using a CW Nd:YAG laser (λ = 1.319 μm) for a probe and novel pulsed, tunable, infrared dye laser (λ = 1.10 to 1.13 μm) with photon energies near the Si bandgap, for a pump, the free-carrier lifetime was determined from transient absorption measurements to a maximum depth of 3.0 cm from the surface of an ingot. The spatial dependence of the free-carrier lifetime and the distribution of precipitates (determined from infrared probe transmission measurements) measured along the growth axis of an ingot were found to be strongly related to the spatial dependence of the I–V characteristics of large area solar cells fabricated from the subsequently wafered ingot.

scholarly journals LLAMA: The MBH–σ⋆ relation of the most luminous local AGNs

2020 ◽  
Vol 634 ◽  
pp. A114 ◽  
Author(s):  
Turgay Caglar ◽  
Leonard Burtscher ◽  
Bernhard Brandl ◽  
Jarle Brinchmann ◽  
Richard I. Davies ◽  
...  
Keyword(s):  
Black Hole ◽  
Near Infrared ◽  
Velocity Dispersion ◽  
Signal To Noise Ratio ◽  
Broad Line ◽  
Host Galaxies ◽  
Spatially Resolved ◽  
Stellar Velocity ◽  
Black Hole Masses

Context. The MBH–σ⋆ relation is considered a result of coevolution between the host galaxies and their supermassive black holes. For elliptical bulge hosting inactive galaxies, this relation is well established, but there is still discussion concerning whether active galaxies follow the same relation. Aims. In this paper, we estimate black hole masses for a sample of 19 local luminous active galactic nuclei (AGNs; LLAMA) to test their location on the MBH–σ⋆ relation. In addition, we test how robustly we can determine the stellar velocity dispersion in the presence of an AGN continuum and AGN emission lines, and as a function of signal-to-noise ratio. Methods. Supermassive black hole masses (MBH) were derived from the broad-line-based relations for Hα, Hβ, and Paβ emission line profiles for Type 1 AGNs. We compared the bulge stellar velocity dispersion (σ⋆) as determined from the Ca II triplet (CaT) with the dispersion measured from the near-infrared CO (2-0) absorption features for each AGN and find them to be consistent with each other. We applied an extinction correction to the observed broad-line fluxes and we corrected the stellar velocity dispersion by an average rotation contribution as determined from spatially resolved stellar kinematic maps. Results. The Hα-based black hole masses of our sample of AGNs were estimated in the range 6.34 ≤ log MBH ≤ 7.75 M⊙ and the σ⋆CaT estimates range between 73 ≤ σ⋆CaT ≤ 227 km s−1. From the so-constructed MBH − σ⋆ relation for our Type 1 AGNs, we estimate the black hole masses for the Type 2 AGNs and the inactive galaxies in our sample. Conclusions. We find that our sample of local luminous AGNs is consistent with the MBH–σ⋆ relation of lower luminosity AGNs and inactive galaxies, after correcting for dust extinction and the rotational contribution to the stellar velocity dispersion.

scholarly journals Spatially resolved fibre cavity ring down spectroscopy

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Rongzhang Chen ◽  
Zhaoqiang Peng ◽  
Mohan Wang ◽  
Aidong Yan ◽  
Shuo Li ◽  
...  
Keyword(s):  
Rayleigh Scattering ◽  
Signal To Noise Ratio ◽  
Ring Cavity ◽  
Optical Gain ◽  
High Sensitivity ◽  
Spatial Location ◽  
Cavity Ring Down Spectroscopy ◽  
Spatially Resolved ◽  
Active Fibre ◽  
Cavity Ring Down

AbstractThis paper presents a fibre cavity ring down spectroscopy probed by Rayleigh scattering optical frequency domain reflectometry (OFDR), which provides spatial location of stimuli and improved signal to noise ratio for distributed sensing measurements. A section of optical fibre was integrated into an active fibre ring cavity with optical gain and interrogated by the OFDR system for 11 cycles with a single laser scan. Through the cavity ring down configuration, root-mean-squared (RMS) noise of distributed temperature and strain measurements was reduced to 6.9 mK and less than 0.1 με, respectively for 1-cm spatially resolved measurements. Our work shows that the active fibre cavity configuration can be combined with distributed fibre sensing schemes to achieve both high spatial resolution and high sensitivity measurements.

Atomistic Simulation and Density Functional Analysis of Ni(111)-ZrO2(100)(Cubic) and NiO(111)-Ni(111)-ZrO2(100)(Cubic) Interfaces

2000 ◽  
Vol 654 ◽  
Author(s):  
Chang-Xin Guo ◽  
Donald E. Ellis ◽  
Vinayak P. Dravid ◽  
Luke Brewer
Keyword(s):  
First Principles ◽  
Atomistic Simulation ◽  
Density Functional ◽  
Depth Profiling ◽  
Interface Plane ◽  
Functional Theory ◽  
Spatially Resolved ◽  
Microscopy Data ◽  
Energy Profiling ◽  
Good Agreement

AbstractThe atomic arrangement and electronic structure in the vicinity of Ni(111)- ZrO2(100)(Cubic) and NiO(111)-Ni(111)-ZrO2(100)(Cubic) interfaces have been studied by atomistic simulation and by first-principles Density Functional theory. “Depth Profiling” is carred out in both methodologies, to determine modifications of cohesive energy and electron distribution of atomic layers from the interface plane. The energy profiling results show the interface consists of only a few atomic layers. Simulation results and electron density analyses are in good agreement with High Resolution Spatially Resolved Electron Microscopy data.

Recording, Processing and Extracting Information From Sequences of Spatially Resolved Eels Spectra

1997 ◽  
Vol 3 (S2) ◽  
pp. 939-940
Author(s):  
N. Brun ◽  
C. Colliex ◽  
K. Suenaga ◽  
M. Tencé ◽  
N. Bonnet
Keyword(s):  
Energy Loss ◽  
Signal To Noise Ratio ◽  
Energy Channel ◽  
Spectral Changes ◽  
New Methods ◽  
Spatially Resolved ◽  
Efficient Processing ◽  
Spectrum Imaging ◽  
Electron Energy Loss ◽  
Loss Range

The sophisticated acquisition procedures now available in time or space resolved spectroscopies, also known as spectrum-imaging modes, produce large amounts of data which require specific developments for efficient processing and information extraction. For instance, in electron energy-loss spectroscopy (EELS), a line-spectrum consists of typically one hundred spectra recorded at regular intervals when scanning the subnanometer incident electron probe across the feature of interest: interfaces, multilayers or nanostructures of various shapes and dimensions. The useful information in any of these spectra depends on many factors such as the problem under investigation, the involved energy-loss range or the signal-to-noise ratio of the different features. However it is generally contained in the spectral changes, as well in energy channel as in position along the sequence.To detect, measure and identify these variations, new methods have to be developed and the accompanying algorithms to be implemented. A first category encompasses all the routines which apply successively to all spectra in the sequence the well-known software which have been elaborated for processing individual spectra.

scholarly journals Spectroscopic detection of coronal plasma flows in loops undergoing thermal non-equilibrium cycles

2020 ◽  
Vol 634 ◽  
pp. A54 ◽  
Author(s):  
Gabriel Pelouze ◽  
Frédéric Auchère ◽  
Karine Bocchialini ◽  
Clara Froment ◽  
Susanna Parenti ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Line Of Sight ◽  
Doppler Velocity ◽  
Temperature Plasma ◽  
Imaging Spectrometer ◽  
Periodic Flows ◽  
Evaporation And Condensation ◽  
Spatially Resolved ◽  
Euv Imaging ◽  
Non Equilibrium

Context. Long-period intensity pulsations were recently detected in the EUV emission of coronal loops and attributed to cycles of plasma evaporation and condensation driven by thermal non-equilibrium (TNE). Numerical simulations that reproduce this phenomenon also predict the formation of periodic flows of plasma at coronal temperatures along some of the pulsating loops. Aims. We aim to detect these predicted flows of coronal-temperature plasma in pulsating loops. Methods. We used time series of spatially resolved spectra from the EUV imaging spectrometer (EIS) onboard Hinode and tracked the evolution of the Doppler velocity in loops in which intensity pulsations have previously been detected in images of SDO/AIA. Results. We measured signatures of flows that are compatible with the simulations but only for a fraction of the observed events. We demonstrate that this low detection rate can be explained by line of sight ambiguities combined with instrumental limitations, such as low signal-to-noise ratio or insufficient cadence.

X-ray Microprobe Studies of Materials Problems Related to Microelectromechanical Systems (MEMS) Structures

1999 ◽  
Vol 605 ◽  
Author(s):  
N. Mölders ◽  
P.J. Schilling ◽  
J. Göttert ◽  
H.O. Moser ◽  
V. Saile
Keyword(s):  
Microelectromechanical Systems ◽  
Mems Devices ◽  
X Ray ◽  
Spatially Resolved ◽  
Fluorescence Measurements ◽  
Transmission Measurements ◽  
Properties Of Materials ◽  
Materials Used ◽  
Micro Systems

AbstractThe understanding of the physical, chemical and mechanical properties of materials used in micro-electromechanical systems (MEMS) is essential for the successful application. For the characterization of such materials, it is often necessary to utilize a probe which can gather information on the same scale as the devices themselves. Based on these needs, x-ray microprobe analysis has been employed to perform spatially resolved measurements on several problems related to the fabrication of MEMS devices. These include spatially resolved transmission measurements of the homogeneity of transmitted flux through a graphite mask, micro-fluorescence measurements to assess elemental distributions, and micro-XANES measurements to follow the breakdown of new sulfone-based x-ray resists. These studies demonstrate the value of such an instrument in the characterization of micro-systems.

Sign in / Sign up

Export Citation Format

Share Document