scholarly journals Graphite oxidation chemistry is relevant for designing cleaning strategies for radiocarbon dating samples

2019 ◽  
Vol 11 (22) ◽  
pp. 2880-2887 ◽  
Author(s):  
Amir Joorab Doozha ◽  
Kristin M. Poduska
Keyword(s):  
Graphite Oxide ◽  
Radiocarbon Dating ◽  
Carbon Materials ◽  
Graphite Oxidation ◽  
Oxidation Chemistry

We demonstrate that mixtures of graphite and lab-oxidized graphenic carbon materials can be separated into three individual components (graphite, graphene/graphite oxide and oxidative debris) by a series of aqueous treatments.

Research on Carbon Materials with Synthesis and Characterization of Graphene-Based

2014 ◽  
Vol 1003 ◽  
pp. 100-104
Author(s):  
Pei Pei Li ◽  
Bao Xiang Deng
Keyword(s):  
Thermal Stability ◽  
Graphite Oxide ◽  
Electronic Structures ◽  
Carbon Materials ◽  
Reduction Method ◽  
Synthesis And Characterization ◽  
Two Dimensional ◽  
Graphite Oxidation ◽  
Oxidation Reduction

Carbon materials has been a popular application materials, especially in graphene. Graphene, the mother of all graphitic materials, has emerged to become an exciting two-dimensional material with wondrous properties. Atomic and electronic structures of graphene have been investigated by employing a variety of micro-scopic, spectroscopic, and other techniques. The results show it has better thermal stability, and larger surface area than graphite, graphite oxide. Keywords: graphite; oxidation-reduction method; graphite oxide; graphene

scholarly journals Raman investigation of laser-induced structural defects of graphite oxide films

2018 ◽  
Vol 167 ◽  
pp. 04011 ◽  
Author(s):  
Valentino Romano ◽  
Lorenzo Torrisi ◽  
Mariapompea Cutroneo ◽  
Vladimir Havranek ◽  
Giovanna D’Angelo
Keyword(s):  
Raman Spectroscopy ◽  
Laser Irradiation ◽  
Graphite Oxide ◽  
Figure Of Merit ◽  
Structural Changes ◽  
Carbon Materials ◽  
Structural Defects ◽  
Laser Fluences ◽  
Research Activities ◽  
Non Destructive

Since the beginning of intensive studies on graphene and graphitic materials, Raman spectroscopy has always been used as a characterisation technique. This is due to two main reasons: the non-destructive nature of this experimental technique and its ability to distinguish between the plethora of existing carbon materials. One of the most challenging research activities concerns the production of graphene microcircuits. To address this issue, a possible strategy is to directly reduce and pattern graphite oxide (GO) film by laser irradiation. The objective of this study is to evaluate the laser irradiation-induced structural changes on thin GO films by using Micro-Raman spectroscopy. We used as a source a Nd:YAG laser (1064 nm) and different laser fluences: 15 J/cm2, 7.5 J/cm2 and 5 J/cm2. We have analyzed the modifications of the main Raman contributions of these graphitic materials: the D band (defect induced band), the G band (band due to sp2 hybridized carbon atoms) and the 2D band (D band overtone). In particular, we found out that our figure of merit (FOM) parameters, i.e. the intensity ratio ID/IG (for the D band and G band) and I2D/IG (for the 2D band and G band), change with the laser fluences, revealing a different effect induced by the laser irradiation. The best results are found in the sample irradiated with 5 J/cm2, suggesting that higher fluences do not lead to better results.

scholarly journals Preparation and photocatalytic activity of TiO2-exfoliated graphite oxide composite using an ecofriendly graphite oxidation method

2015 ◽  
Vol 359 ◽  
pp. 868-874 ◽  
Author(s):  
Vanessa Zanon Baldissarelli ◽  
Thiago de Souza ◽  
Luisa Andrade ◽  
Luiz Fernando Cappa de Oliveira ◽  
Humberto Jorge José ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Graphite Oxide ◽  
Exfoliated Graphite ◽  
Oxidation Method ◽  
Oxide Composite ◽  
Graphite Oxidation

Three-dimensional distribution of ribulose-1, 5-bisphosphate carboxylase/oxygemase during the early development of proplastids in dark-grown Euglena cells transferred to an inorganic medium

1990 ◽  
Vol 48 (3) ◽  
pp. 906-907
Author(s):  
Tomoko Ehara ◽  
Shuji Sumida ◽  
Tetsuaki Osafune ◽  
Eiji Hase
Keyword(s):  
Cell Suspension ◽  
Euglena Gracilis ◽  
Carbon Materials ◽  
Three Dimensional ◽  
Peripheral Region ◽  
Plastid Development ◽  
Bisphosphate Carboxylase ◽  
Inorganic Medium ◽  
Ribulose 1 ◽  
Dimensional Distribution

As shown previously, Euglena cells grown in Hutner’s medium in the dark without agitation accumulate wax as well as paramylum, and contain proplastids showing no internal structure except for a single prothylakoid existing close to the envelope. When the cells are transferred to an inorganic medium containing ammonium salt and the cell suspension is aerated in the dark, the wax was oxidatively metabolized, providing carbon materials and energy 23 for some dark processes of plastid development. Under these conditions, pyrenoid-like structures (called “pro-pyrenoids”) are formed at the sites adjacent to the prolamel larbodies (PLB) localized in the peripheral region of the proplastid. The single prothylakoid becomes paired with a newly formed prothylakoid, and a part of the paired prothylakoids is extended, with foldings, in to the “propyrenoid”. In this study, we observed a concentration of RuBisCO in the “propyrenoid” of Euglena gracilis strain Z using immunoelectron microscopy.

RADIOCARBON DATING DYNAMICS OF LANDSLIDES IN THE UPPER REACHES OF THE MZYMTA RIVER BASIN (WESTERN CAUCASUS)

2018 ◽  
pp. 66-72
Author(s):  
Yu. K. Vasil’chuk ◽  
E. S. Slyshkina ◽  
A. V. Bershov
Keyword(s):  
River Basin ◽  
Radiocarbon Dating ◽  
Northern Slope ◽  
Southern Slope ◽  
Western Caucasus ◽  
Ancient Landslide

The article contains materials on the study of landslide deposits in the upper reaches of the Mzymta river basin. The results of14C analysis showed that the youngest landslides are common on the southern slope of the Psekhako Ridge and date back to less than 200 and 390±90, 400±70 years ago BP and more than 770±150 years BP. The most ancient landslide-collapse on the northern slope of the Aibga Ridge and dates back to 1110±90 years BP.

The excavation of a medieval ring-ditch enclosure at Hayknowes Farm, Annan, Dumfries and Galloway

2001 ◽  
Vol 23 (2) ◽  
pp. 119-139
Author(s):  
R. A. GREGORY ◽  
D. W. HALL ◽  
D. W. SHIMWELL
Keyword(s):  
Radiocarbon Dating ◽  
Structural Phase ◽  
Morphological Characteristics ◽  
Internal Structures

Excavation at a crop-mark site found close to Annan, Dumfries and Galloway, revealed evidence of a ring-ditch containing a number of intriguing internal structures. Initially this was presumed to be a prehistoric monument, but pottery and radiocarbon dating, unexpectedly, indicated that the main structural phase of the site falls between the 11th-13th centuries AD. This suggests that a degree of caution is required when interpreting crop-mark sites on morphological characteristics alone. Moreover this excavation makes clear that morphological interpretation can have a constraining influence on excavation strategy, so caution is required when designing fieldwork programmes.

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