scholarly journals Rapid electron transfer by the carbon matrix in natural pyrogenic carbon

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Tianran Sun ◽  
Barnaby D. A. Levin ◽  
Juan J. L. Guzman ◽  
Akio Enders ◽  
David A. Muller ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Carbon Matrix ◽  
Pyrogenic Carbon

Impact of Graphitic Structures in Pyrogenic Carbon on Microbial Reduction of Ferrihydrite

2021 ◽  
Author(s):  
wentao yu ◽  
baoliang chen
Keyword(s):  
Electron Transfer ◽  
Pyrolysis Temperature ◽  
Shewanella Oneidensis ◽  
Exchange Capacity ◽  
Microbial Reduction ◽  
Systematic Evaluation ◽  
Extracellular Electron Transfer ◽  
Pyrogenic Carbon ◽  
The Impact

<p>Pyrogenic carbon plays important roles in microbial reduction of ferrihydrite by shuttling electrons in the extracellular electron transfer (EET) processes. Despite its importance, a full assessment on the impact of graphitic structures in pyrogenic carbon on microbial reduction of ferrihydrite has not been conducted. This study is a systematic evaluation of microbial ferrihydrite reduction by Shewanella oneidensis MR-1 in the presence of pyrogenic carbon with various graphitization extents. The results showed that the rates and extents of microbial ferrihydrite reduction were significantly enhanced in the presence of pyrogenic carbon, and increased with increasing pyrolysis temperature. Combined spectroscopic and electrochemical analyses suggested that the rate of microbial ferrihydrite reduction were dependent on the electrical conductivity of pyrogenic carbon (i.e., graphitization extent), rather than the electron exchange capacity. The key role of graphitic structures in pyrogenic carbon in mediating EET was further evidenced by larger microbial electrolysis current with pyrogenic carbon prepared at higher pyrolysis temperatures. This study provides new insights into the electron transfer in the pyrogenic carbon-mediated microbial reduction of ferrihydrite.</p>

Simultaneous Quantification of Electron Transfer by Carbon Matrices and Functional Groups in Pyrogenic Carbon

2018 ◽  
Vol 52 (15) ◽  
pp. 8538-8547 ◽  
Author(s):  
Tianran Sun ◽  
Barnaby D. A. Levin ◽  
Michael P. Schmidt ◽  
Juan J. L. Guzman ◽  
Akio Enders ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Functional Groups ◽  
Simultaneous Quantification ◽  
Pyrogenic Carbon

scholarly journals Suppressing peatland methane production by electron snorkeling through pyrogenic carbon in controlled laboratory incubations

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tianran Sun ◽  
Juan J. L. Guzman ◽  
James D. Seward ◽  
Akio Enders ◽  
Joseph B. Yavitt ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Methane Production ◽  
Fire Regime ◽  
Extracellular Electron Transfer ◽  
Climate Conditions ◽  
Fire Emissions ◽  
Global Carbon Budget ◽  
Pyrogenic Carbon ◽  
Climate Cooling ◽  
Northern Peatlands

AbstractNorthern peatlands are experiencing more frequent and severe fire events as a result of changing climate conditions. Recent studies show that such a fire-regime change imposes a direct climate-warming impact by emitting large amounts of carbon into the atmosphere. However, the fires also convert parts of the burnt biomass into pyrogenic carbon. Here, we show a potential climate-cooling impact induced by fire-derived pyrogenic carbon in laboratory incubations. We found that the accumulation of pyrogenic carbon reduced post-fire methane production from warm (32 °C) incubated peatland soils by 13–24%. The redox-cycling, capacitive, and conductive electron transfer mechanisms in pyrogenic carbon functioned as an electron snorkel, which facilitated extracellular electron transfer and stimulated soil alternative microbial respiration to suppress methane production. Our results highlight an important, but overlooked, function of pyrogenic carbon in neutralizing forest fire emissions and call for its consideration in the global carbon budget estimation.

A light optical diffractometer for electron microscopical images operating in line

1978 ◽  
Vol 36 (1) ◽  
pp. 86-87
Author(s):  
P. Bonhomme ◽  
A. Beorchia
Keyword(s):  
Electron Microscopy ◽  
Electron Transfer ◽  
Electron Microscope ◽  
Image Converter ◽  
Coherent Light ◽  
Spatial Filters ◽  
Electron Image ◽  
Electron Microscopical ◽  
Working Parameters ◽  
Amorphous Part

We have already described (1.2.3) a device using a pockel's effect light valve as a microscopical electron image converter. This converter can be read out with incoherent or coherent light. In the last case we can set in line with the converter an optical diffractometer. Now, electron microscopy developments have pointed out different advantages of diffractometry. Indeed diffractogram of an image of a thin amorphous part of a specimen gives information about electron transfer function and a single look at a diffractogram informs on focus, drift, residual astigmatism, and after standardizing, on periods resolved (4.5.6). These informations are obvious from diffractogram but are usualy obtained from a micrograph, so that a correction of electron microscope parameters cannot be realized before recording the micrograph. Diffractometer allows also processing of images by setting spatial filters in diffractogram plane (7) or by reconstruction of Fraunhofer image (8). Using Electrotitus read out with coherent light and fitted to a diffractometer; all these possibilities may be realized in pseudoreal time, so that working parameters may be optimally adjusted before recording a micrograph or before processing an image.

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