Strain-related carbon ordering on a sub-mm scale: a comparison of carbonate microfabrics and organic carbon nanostructure within a single sample.

2021 ◽  
Author(s):  
Lauren Kedar ◽  
Clare Bond ◽  
David Muirhead
Keyword(s):  
Organic Carbon ◽  
Thermal Maturity ◽  
Strain Localisation ◽  
Calcite Crystal ◽  
Carbon Nanostructure ◽  
Spectral Parameters ◽  
Carbon Particles ◽  
Heterogeneous Rock ◽  
Carbonate Sample ◽  
Raman Spectral

<p>Organic carbon in rocks undergoes nanostructural changes when exposed to increased temperatures or strain. These changes can be identified using Raman spectroscopy, giving information about thermal maturity and strain conditions. However, it is well documented that in a heterogeneous rock, strain can be highly localised, evident in microstructural variations such as strain shadows, sub-grain development, twinning, and the rotation and alignment of crystal axes. In this study we map microstructural textures in deformed calcite through optical microscopy and EBSD of calcite crystal axes. This textural map is compared to mapped Raman spectral parameters of organic carbon particles in the same thin section. A comparison of the maps allows assessment of the extent to which Raman spectral parameters and hence carbon nanostructure is influenced by strain at a sub-mm scale. The study highlights the sensitivity of organic carbon nanostructure to sub-mm scale changes in strain localisation within a single deformed carbonate sample.</p>

SYNTHESIS OF CATALYST-FREE AND TEMPERATURE CONTROLLED MORPHOLOGIES OF CARBON NANOSTRUCTURES USING BOTANICAL HYDROCARBON: CASTOR OIL

NANO ◽  
2011 ◽  
Vol 06 (03) ◽  
pp. 215-223 ◽  
Author(s):  
RAJESH KUMAR ◽  
R. S. TIWARI ◽  
O. N. SRIVASTAVA
Keyword(s):  
Electron Microscope ◽  
Castor Oil ◽  
Carbon Nanoparticles ◽  
Carbon Nanostructures ◽  
Tubular Structure ◽  
Carbon Nanostructure ◽  
Uniform Size ◽  
Carbon Particles ◽  
Transmission Electron ◽  
Botanical Hydrocarbon

Castor oil (combination of fatty acids) precursor containing hydrocarbon with less amount of oxygen is used first time for synthesis of different carbon nanostructures (i.e., agglomerated carbon nanoparticles, carbon nanobeads and carbon tubular structure). The agglomerated carbon nanoparticles, carbon nanobeads and carbon tubular structure were synthesized by applying CVD method at different temperature using castor oil as new carbon precursor without any catalyst. The synthesis of carbon nanostructure is free from additional catalyst as this hydrocarbon (castor oil) is cheap with abundant sources of carbon. The effect of pyrolysis temperatures on the size, quality and quantity of the synthesized carbon shape were investigated. Interestingly, the morphology of the carbon nanostructures can be controlled in shape from agglomerated carbon nanoparticle to nanobeads to carbon tubular structure just by increasing the temperature from 750°C to 800°C to 850°C, respectively. These nanobeads are chains of uniform size of graphitized carbon spheres. These chains comprised individual carbon particles size of ~ 450 nm. The products were characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR).

scholarly journals Raman Spectroscopic Study of Coal Samples during Heating

2019 ◽  
Vol 9 (21) ◽  
pp. 4699 ◽  
Author(s):  
Yingfang Xie ◽  
Jinglin You ◽  
Liming Lu ◽  
Min Wang ◽  
Jian Wang
Keyword(s):  
High Temperature ◽  
Spectroscopic Study ◽  
Spectral Characteristics ◽  
Blue Shift ◽  
Carbonaceous Materials ◽  
Temperature Dependent ◽  
Spectral Parameters ◽  
Raman Spectroscopic ◽  
Raman Spectroscopic Study ◽  
Raman Spectral

Raman spectroscopy can be used to record the characteristic spectra of carbonaceous materials. The D and G bands are the most popular and most important spectral characteristics when discussing carbonaceous materials. In this paper, a Raman spectroscopic study of different coals was first carried out using a 355 nm wavelength laser beam as an excitation source. The spectral parameters of the resultant spectra were evaluated and analyzed. Raman spectral characteristics of different kinds of coals were explored. The high temperature-dependent Raman spectra of the coals were further collected in a temperature range from 298 to 1473 K in order to investigate the transformations of the internal structure of the coals during the pyrolysis process. An abnormal blue shift of the G band occurred at moderate temperature (600–900 K), and the intensity of the G band became weaker at high temperatures, indicating pyrolysis and graphitization of the sample at moderate and high temperature, respectively.

scholarly journals Primary and secondary organic carbon downwind of Mexico City

2009 ◽  
Vol 9 (18) ◽  
pp. 6793-6814 ◽  
Author(s):  
X.-Y. Yu ◽  
R. A. Cary ◽  
N. S. Laulainen
Keyword(s):  
Organic Carbon ◽  
Mexico City ◽  
Linear Regression Analysis ◽  
Total Carbon ◽  
Particulate Carbon ◽  
Carbon Particles ◽  
Matter Transport ◽  
Secondary Organic Carbon ◽  
T1 And T2 ◽  
Odd Nitrogen

Abstract. In order to study particulate matter transport and transformation in the Megacity environment, fine particulate carbon was measured simultaneously at two supersites, suburban T1 and rural T2, downwind of Mexico City during the MILAGRO field campaign in March 2006. Organic carbon (OC), element carbon (EC), and total carbon (TC=OC+EC) were determined in near real-time using a Sunset semi-continuous OCEC field analyzer. The semi-empirical EC tracer method was used to derive primary organic carbon (POC) and secondary organic carbon (SOC). Diurnal variations of primary and secondary carbon were observed at T1 and T2, which resulted from boundary layer inversion and impacted by local traffic patterns. The majority of organic carbon particles at T1 and T2 were secondary. The SOCTC% (SOC%=SOC/TC×100%) at T1 ranged from 0.5–93.8% with an average of 63.5±17.2%. The SOCTC% at T2 ranged from 9.3–98.1% with an average of 67.4±12.4%. The average EC to PM2.5 percentage (ECPM%=EC/PM2.5×100%) and OCPM% were 6.0% and 20.0% over the whole sampling time at T1. The POC to PM percentage (POCPM%) and SOCPM% were 3.7% and 16.3%, respectively at the same site. The maximum ECPM% was 21.2%, and the maximum OCPM% was 57.2% at T1. The maximum POCPM% was 12.9%, and the maximum SOCPM% was 49.7% at T1. Comparison of SOC and POC at T1 and T2 showed similar characteristics under favorable meteorological conditions, which indicated that transport from T1 towards T2 took place. Strong correlations between EC and carbon monoxide (CO) and odd nitrogen species (NO and NOx) were observed at T1. This indicated that EC had nearby sources, such as local traffic emissions. The EC/CO ratio derived by linear regression analysis, with units of μg C/m3 and μg/m3, respectively, was 0.004 at T1. Correlations were also seen between OC and SOC vs. the sum of oxidants, such as O3 and NO2, suggesting the secondary nature of carbons observed at T1.

scholarly journals Diagenesis and Thermal Maturity of the Cogollo Group rocks in the ANH-CR-Montecarlo-1X well, Cesar-Ranchería Basin, Colombia

2021 ◽  
Vol 48 (3) ◽  
Author(s):  
Carlos A Ríos ◽  
Mayra A Vargas ◽  
Mario García
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Temporal Distribution ◽  
Thermal Maturity ◽  
Secondary Porosity ◽  
Diagenetic Processes ◽  
Geological Unit ◽  
Porosity And Permeability ◽  
The Impact ◽  
Ferrous Carbonate

In ANH-CR-Montecarlo-1X well located in the southern sector of the Cesar-Ranchería basin, Colombia, rocks of the middle Cretaceous outcrop, which have been defined as belonging to the Cogollo Group. The present study concerns with the diagenetic evolution and thermal maturity of this geological unit, integrating petrographic techniques (thin section microscopy and scanning electron microscopy), geochemistry (total organic carbon and pyrolysis rock-eval) and basic petrophysics, to establish the thermal maturity and the potential of rocks as reservoirs of conventional and unconventional hydrocarbons. The results of petrographic and diagenetic analysis revealed that the rocks compositionally correspond to quartz sandstones and graywackes and carbonate rocks to mudstones and wackestones; which were affected by diagenetic processes such as compaction, mineral neoformations distinguishing minerals from the group of clays that cover the grains of the framework, and other types of precipitates of cements such as silica, ferrous and non-ferrous carbonate, some of these present partial and/or total dissolution, for which secondary porosity is recognized, also metasomatisms, where processes of chloritization and illitization of the argillaceous matrix are observed, alteration of feldspars to ferrous and non-ferrous carbonate, which affects the porosity and permeability of the rock; and recrystallization from micrite to sparite and carbonate precipitation in calcareous rocks. The study also showed that the rocks were more affected by compaction than precipitation of the different cements. The research contributes to the understanding of the impact of diagenetic processes on porosity, as well as their spatial and temporal distribution, providing diagenetic paragenesis for both siliciclastic and carbonatic rocks. When we classifying siliciclastic rocks as potential reservoir rocks, low potential results were obtained as conventional reservoirs but has good potential as non-conventional reservoirs (tight sandstones), this respect to porosity and permeability data. The geochemical studies in the calcareous rocks exhibited low to good content of total organic carbon, overmaturity state and a low generation potential with type III and IV kerogens.

scholarly journals Effect of short-term formaldehyde fixation on Raman spectral parameters of bone quality

2018 ◽  
Vol 23 (11) ◽  
pp. 1 ◽  
Author(s):  
Imke A.K. Fiedler ◽  
Michele Casanova ◽  
Tobias Keplinger ◽  
Björn Busse
Keyword(s):  
Bone Quality ◽  
Short Term ◽  
Spectral Parameters ◽  
Raman Spectral

1D depth burial history and thermal maturity modelling of the Toolebuc Formation, Queensland

2016 ◽  
Vol 56 (2) ◽  
pp. 590
Author(s):  
Behnam Talebi
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Vitrinite Reflectance ◽  
Tight Oil ◽  
Thermal Maturity ◽  
Burial History ◽  
The Us ◽  
Petroleum Wells ◽  
Erosional Event ◽  
Eromanga Basin

The Toolebuc Formation in the Eromanga and Carpentaria basins in western Queensland shares many characteristics with successful tight oil plays in the US. A study by the Geological Survey of Queensland has examined key parameters for this formation, including depth, thickness, lithology, mineralogy, maturity (both vitrinite reflectance and Tmax), total organic carbon and mud gas compositions and identified a possible play fairway in the central Eromanga Basin. Mudgas wetness ratios indicate that in areas modelled to be more mature, oil may be present in the Toolebuc Formation. These areas are typically in the central Eromanga Basin where the Toolebuc Formation is deepest, though oil responses have been calculated for wells that are shallower. This is contradicted by the apparent maturity of the formation based on vitrinite reflectance and Tmax measurements. Initial burial history modelling of the six petroleum wells indicates that DIO Hammond–1, SSL Clinton–1, DIO Tanbar North–1 and DIO Marengo–1 are in main oil window (0.7–1.0 %Ro) while DIO Denley–1 and DIO Ingella–1 are in the early oil window (0.55–0.7 %Ro). A single erosional event of 550 m of the Winton Formation has been assumed for this modelling. These wells are the deepest intersections of the Toolebuc Formation where it has been modelled to have higher maturity, and mudgas wetness ratios indicate oil may be present. Further refinement of these models and examination of additional wells is needed to better understand the potential for the Toolebuc Formation to have generated petroleum.

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