scholarly journals Evolution and Enabling Capabilities of Spatially Resolved Techniques for the Characterization of Heterogeneously Catalyzed Reactions

ACS Catalysis ◽  
2016 ◽  
Vol 6 (2) ◽  
pp. 1356-1381 ◽  
Author(s):  
Kevin Morgan ◽  
Jamal Touitou ◽  
Jae-Soon Choi ◽  
Ciarán Coney ◽  
Christopher Hardacre ◽  
...  
Keyword(s):  
Spatially Resolved ◽  
Catalyzed Reactions

ChemInform Abstract: Evolution and Enabling Capabilities of Spatially Resolved Techniques for the Characterization of Heterogeneously Catalyzed Reactions

ChemInform ◽  
2016 ◽  
Vol 47 (14) ◽  
Author(s):  
Kevin Morgan ◽  
Jamal Touitou ◽  
Jae-Soon Choi ◽  
Ciaran Coney ◽  
Christopher Hardacre ◽  
...  
Keyword(s):  
Spatially Resolved ◽  
Catalyzed Reactions

scholarly journals Use of Amperometric and Potentiometric Probes in Scanning Electrochemical Microscopy for the Spatially-Resolved Monitoring of Severe Localized Corrosion Sites on Aluminum Alloy 2098-T351

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1132 ◽  
Author(s):  
Rejane M. P. da Silva ◽  
Javier Izquierdo ◽  
Mariana X. Milagre ◽  
Abenchara M. Betancor-Abreu ◽  
Isolda Costa ◽  
...  
Keyword(s):  
Scanning Electrochemical Microscopy ◽  
Oxygen Depletion ◽  
Localized Corrosion ◽  
Alloy Surface ◽  
Al Alloy ◽  
Spatially Resolved ◽  
Lower Oxygen ◽  
Local Ph ◽  
Electrochemical Microscopy

Amperometric and potentiometric probes were employed for the detection and characterization of reactive sites on the 2098-T351 Al-alloy (AA2098-T351) using scanning electrochemical microscopy (SECM). Firstly, the probe of concept was performed on a model Mg-Al galvanic pair system using SECM in the amperometric and potentiometric operation modes, in order to address the responsiveness of the probes for the characterization of this galvanic pair system. Next, these sensing probes were employed to characterize the 2098-T351 alloy surface immersed in a saline aqueous solution at ambient temperature. The distribution of reactive sites and the local pH changes associated with severe localized corrosion (SLC) on the alloy surface were imaged and subsequently studied. Higher hydrogen evolution, lower oxygen depletion and acidification occurred at the SLC sites developed on the 2098-T351 Al-alloy.

scholarly journals Loading and spatially resolved characterization of a cold atomic ensemble inside a hollow-core fiber

2021 ◽  
Vol 103 (6) ◽  
Author(s):  
Thorsten Peters ◽  
Leonid P. Yatsenko ◽  
Thomas Halfmann
Keyword(s):  
Atomic Ensemble ◽  
Hollow Core ◽  
Spatially Resolved ◽  
Core Fiber

scholarly journals Time- and spatially-resolved characterization of electrical discharge machining plasma

2008 ◽  
Vol 17 (2) ◽  
pp. 024008 ◽  
Author(s):  
A Descoeudres ◽  
Ch Hollenstein ◽  
G Wälder ◽  
R Demellayer ◽  
R Perez
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Spatially Resolved

scholarly journals The risk to fishery performance associated with spatially resolved management of Antarctic krill (Euphausia superba) harvesting

2009 ◽  
Vol 66 (10) ◽  
pp. 2148-2154 ◽  
Author(s):  
Simeon L. Hill ◽  
Philip N. Trathan ◽  
David J. Agnew
Keyword(s):  
Antarctic Krill ◽  
Euphausia Superba ◽  
Ecosystem Approach ◽  
Fishing Effort ◽  
Target Species ◽  
Ecosystem Models ◽  
Spatially Resolved ◽  
Management Actions ◽  
Antarctic Krill Euphausia Superba

Abstract Hill, S. L., Trathan, P. N., and Agnew, D. J. 2009. The risk to fishery performance associated with spatially resolved management of Antarctic krill (Euphausia superba) harvesting. – ICES Journal of Marine Science, 66: 2148–2154. The ecosystem approach to fisheries attempts to define objectives for target species, the wider ecosystem, and critically, the fishery itself. Proposals for implementing the approach often include spatial restrictions on harvesting, so it is important to understand how these will affect fishery performance. One metric of potential performance is the probability of encountering exploitable densities of a target species at the scale of fishing operations. The probability of encountering exploitable densities of Antarctic krill, Euphausia superba, at the scale of 1 nautical mile during an acoustic survey was predicted by bathymetry and the mean krill density at the larger scale at which the fishery is managed. This suggests that the risk to fishery performance will increase if management actions relocate the fishery into deeper water. The results also suggest that ecosystem models resolved to the spatial scale of management units could usefully predict effects at the scale of fishing operations. However, correct parameterization of these models will require better characterization of threshold densities for efficient exploitation. Finally, the distribution of catch and fishing effort over an entire fishing season reflected the distribution of krill density observed during the survey.

scholarly journals Assessing the Stability of Surface Lights for use in Retrievals of Nocturnal Atmospheric Parameters

2019 ◽  
Author(s):  
Jeremy E. Solbrig ◽  
Steven D. Miller ◽  
Jianglong Zhang ◽  
Lewis Grasso ◽  
Anton Kliewer
Keyword(s):  
Near Infrared ◽  
Correlation Coefficients ◽  
Visible Spectrum ◽  
Light Sources ◽  
Infrared Observations ◽  
Spatially Resolved ◽  
Relative Standard ◽  
Geometric Variables ◽  
The Stability

Abstract. Detection and characterization of aerosols is inherently limited at night due to a lack of sensitivity—information typically provided by visible spectrum observations. The VIIRS Day/Night Band (DNB) onboard the Suomi-NPP satellite is a first-of-its-kind calibrated sensor capable of collecting visible/near-infrared observations during both day and night. Multiple studies have suggested that anthropogenic light emissions such as those from cities and gas flares may be useable as light sources for retrieval of atmospheric properties including cloud and aerosol optical depth. However, their use in this capacity requires proper characterization of their intrinsic variation, which represents a source of retrieval uncertainty. In this study we use 18 months of cloud-cleared VIIRS data collected over five selected geographic domains to assess the stability of anthropogenic light emissions and their response to varied satellite and lunar geometries. Timeseries are developed for each location in each domain for DNB radiance, four infrared channels, and satellite and lunar geometric variables, and spatially-resolved correlation coefficients are computed between DNB radiance and each of the other variables. This analysis finds that while many emissive light sources are too unstable to be used reliably for atmospheric retrievals, some sources exhibit a sufficient stability (relative standard deviation

scholarly journals Spatially Resolved Characterization of Biogenic Manganese Oxide Production within a Bacterial Biofilm

2005 ◽  
Vol 71 (3) ◽  
pp. 1300-1310 ◽  
Author(s):  
Brandy Toner ◽  
Sirine Fakra ◽  
Mario Villalobos ◽  
Tony Warwick ◽  
Garrison Sposito
Keyword(s):  
Careful Consideration ◽  
Bacterial Biofilm ◽  
Bacterial Cells ◽  
X Ray ◽  
Spatially Resolved ◽  
Nexafs Spectroscopy ◽  
Promising Tool ◽  
Scanning Transmission ◽  
X Ray Absorption

ABSTRACT Pseudomonas putida strain MnB1, a biofilm-forming bacterial culture, was used as a model for the study of bacterial Mn oxidation in freshwater and soil environments. The oxidation of aqueous Mn+2 [Mn+2 (aq)] by P. putida was characterized by spatially and temporally resolving the oxidation state of Mn in the presence of a bacterial biofilm, using scanning transmission X-ray microscopy (STXM) combined with near-edge X-ray absorption fine structure (NEXAFS) spectroscopy at the Mn L2,3 absorption edges. Subsamples were collected from growth flasks containing 0.1 and 1 mM total Mn at 16, 24, 36, and 48 h after inoculation. Immediately after collection, the unprocessed hydrated subsamples were imaged at a 40-nm resolution. Manganese NEXAFS spectra were extracted from X-ray energy sequences of STXM images (stacks) and fit with linear combinations of well-characterized reference spectra to obtain quantitative relative abundances of Mn(II), Mn(III), and Mn(IV). Careful consideration was given to uncertainty in the normalization of the reference spectra, choice of reference compounds, and chemical changes due to radiation damage. The STXM results confirm that Mn+2 (aq) was removed from solution by P. putida and was concentrated as Mn(III) and Mn(IV) immediately adjacent to the bacterial cells. The Mn precipitates were completely enveloped by bacterial biofilm material. The distribution of Mn oxidation states was spatially heterogeneous within and between the clusters of bacterial cells. Scanning transmission X-ray microscopy is a promising tool for advancing the study of hydrated interfaces between minerals and bacteria, particularly in cases where the structure of bacterial biofilms needs to be maintained.

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