scholarly journals Lichen preservation in amber: morphology, ultrastructure, chemofossils, and taphonomic alteration

Fossil Record ◽  
2015 ◽  
Vol 18 (2) ◽  
pp. 127-135 ◽  
Author(s):  
C. Hartl ◽  
A. R. Schmidt ◽  
J. Heinrichs ◽  
L. J. Seyfullah ◽  
N. Schäfer ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Fossil Record ◽  
Sem Analysis ◽  
Tissue Preservation ◽  
X Ray ◽  
Fungal Hyphae ◽  
Lichen Thallus ◽  
History Of ◽  
Huge Variety ◽  
Scanning Electron

Abstract. The fossil record of lichens is scarce and many putative fossil lichens do not show an actual physiological relationship between mycobionts and photobionts or a typical habit, and are therefore disputed. Amber has preserved a huge variety of organisms in microscopic fidelity, and so the study of amber fossils is promising for elucidating the fossil history of lichens. However, so far it has not been tested as to how amber inclusions of lichens are preserved regarding their internal characters, ultrastructure, and chemofossils. Here, we apply light microscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and Raman spectroscopy to an amber-preserved Eocene lichen in order to gain information about the preservation of the fossil. The lichen thallus displays lifelike tissue preservation including the upper and lower cortex, medulla, photobiont layer, apothecia, and soredia. SEM analysis revealed globular photobiont cells in contact with the fungal hyphae, as well as impressions of possible former crystals of lichen compounds. EDX analysis permitted the differentiation between halite and pyrite crystals inside the lichen which were likely formed during the later diagenesis of the amber piece. Raman spectroscopy revealed the preservation of organic compounds and a difference between the composition of the cortex and the medulla of the fossil.

scholarly journals On the Investigation of Microstructured Charcoal as an ANFO Blasting Enhancer

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4681 ◽  
Author(s):  
Suzana Gotovac Atlagic ◽  
Andrzej Biessikirski ◽  
Łukasz Kuterasiński ◽  
Michał Dworzak ◽  
Michał Twardosz ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Ammonium Nitrate ◽  
Sem Analysis ◽  
Fuel Oil ◽  
Detonation Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphitic Structure ◽  
Detonation Temperature ◽  
Scanning Electron

In this study, we examined the influence of microstructured charcoal (MC) when added to ammonium nitrate fuel oil (ANFO) samples. We performed a study that investigated ANFOs structure, crystallinity, and morphology by utilizing infrared spectroscopy (IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM), respectively. MC characteristics were probed by Raman spectroscopy and SEM analysis. SEM analysis indicated how fuel oil (FO) covered ammonium nitrate prill. Moreover, the surface of the MC was covered by specific microfibers and microtubes. The disordered graphitic structure of the MC was also confirmed by Raman spectroscopy. Simulation of blasting properties revealed that the addition of MC should decrease blasting parameters like heat explosion, detonation pressure, and detonation temperature. However, the obtained differences are negligible in comparison with the regular ANFO. All analyses indicated that MC was a good candidate as an additive to ANFO.

scholarly journals Investigation of Silicon Carbide Polytypes by Raman Spectroscopy

2014 ◽  
Vol 51 (3) ◽  
pp. 51-57 ◽  
Author(s):  
G. Chikvaidze ◽  
N. Mironova-Ulmane ◽  
A. Plaude ◽  
O. Sergeev
Keyword(s):  
Crystal Structure ◽  
Silicon Carbide ◽  
Raman Spectroscopy ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Stacking Faults ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Abstract Polytypes of colourless and coloured single crystals of silicon carbide (SiC) grown on SiC substrates by chemical vapour deposition are studied using Raman spectroscopy supplemented by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. The SEM analysis of the defect stacking faults, inclusions of defects and their distribution has shown that they correlate with the peak positions of the obtained Raman spectra and with the XRD data on the crystal structure

scholarly journals Improving the reactivity of phenylacetylene macrocycles toward topochemical polymerization by side chains modification

2014 ◽  
Vol 10 ◽  
pp. 1613-1619 ◽  
Author(s):  
Simon Rondeau-Gagné ◽  
Jules Roméo Néabo ◽  
Maxime Daigle ◽  
Katy Cantin ◽  
Jean-François Morin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raman Spectroscopy ◽  
Self Assembly ◽  
Significant Enhancement ◽  
Side Chains ◽  
X Ray Diffraction ◽  
X Ray ◽  
Topochemical Polymerization ◽  
Scanning Electron

The synthesis and self-assembly of two new phenylacetylene macrocycle (PAM) organogelators were performed. Polar 2-hydroxyethoxy side chains were incorporated in the inner part of the macrocycles to modify the assembly mode in the gel state. With this modification, it was possible to increase the reactivity of the macrocycles in the xerogel state to form polydiacetylenes (PDAs), leading to a significant enhancement of the polymerization yields. The organogels and the PDAs were characterized using Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM).

scholarly journals The effect of CaCO3 addition on the crystallization behavior of ZnO crystal glaze fired at different gloss firing and crystallization temperatures

2010 ◽  
Vol 42 (3) ◽  
pp. 345-355 ◽  
Author(s):  
A.R. Jamaludin ◽  
S.R. Kasim ◽  
Z.A. Ahmad
Keyword(s):  
Electron Microscope ◽  
Crystallization Temperature ◽  
Crystallization Behavior ◽  
Isothermal Holding ◽  
Sem Analysis ◽  
Ceramic Product ◽  
X Ray ◽  
Glazed Ceramic ◽  
Zno Crystal ◽  
Scanning Electron

A glazed ceramic product with crystalline structure gives an artistic effect. In this study, the effects of calcium carbonate (CaCO3) addition into glaze batches on the crystallization behavior of crystal glaze were studied. Samples were fired at different gloss firing temperatures ranging from 1000-1200?C with 1060?C crystallization temperature. Xray diffraction (XRD) and energy dispersive X-ray spectrometer (EDX) analysis of the phases identified these crystals as willemite (Zn2SiO4) in the form of spherulites. Scanning electron microscope (SEM) analysis indicated that willemite crystals are in the acicular needle like shape. XRD result showed that the intensities of crystal peaks decreased with the addition of CaCO3 up to 3.0 wt%. However, there was no willemite crystals formation as the amount of CaCO3 raised to 5.0 wt%. Besides that, the results also indicated that willemite growth occurs during isothermal holding at crystallization temperature instead of during cooling from gloss firing temperature.

Facile Electrospinning Preparation of Y3Al5O12 Nanobelts

2013 ◽  
Vol 448-453 ◽  
pp. 3041-3045
Author(s):  
Fei Bi ◽  
Xiang Ting Dong ◽  
Jin Xian Wang ◽  
Gui Xia Liu ◽  
Wen Sheng Yu
Keyword(s):  
Sol Gel ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Ftir Analysis ◽  
X Ray ◽  
Novel Structure ◽  
Group I ◽  
Sol Gel Process ◽  
Composite Nanobelts ◽  
Scanning Electron

PVP/[Y(NO3)3+Al (NO3)3] composite nanobelts were fabricated via electrospinning combined with sol-gel process and novel structure of Y3Al5O12(denoted as YAG for short) nanobelts have been obtained after calcination of the relevant composite nanobelts. The structural properties were characterized by X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). XRD analysis indicated that the composite nanobelts were amorphous, and YAG nanobelts were cubic in structure with space group Ia3d. FTIR analysis manifested that pure YAG nanobelts were formed at 900oC. SEM analysis and histograms revealed that the width of the composite nanobelts and YAG nanobelts were 3.5 μm and 2.4 μm, and the thickness were 240 nm and 112 nm, respectively, under the 95% confidence level. The formation mechanism of YAG nanobelts was discussed in detail.

Wear Behavior of TiB2/GNPs and B4C/GNPs Reinforced AA6061 Matrix Composites

2021 ◽  
Vol 143 (11) ◽  
Author(s):  
Safa Polat ◽  
Yavuz Sun ◽  
Engin C¸evik
Keyword(s):  
Wear Behavior ◽  
Sem Analysis ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Pressure Infiltration ◽  
X Ray ◽  
Wear Rates ◽  
Graphene Nanoparticles ◽  
Infiltration Method ◽  
Scanning Electron

Abstract In this study, it was aimed to investigate the effects of reinforcements used for improving the thermal properties of AA6061 alloy on wear resistance. For this purpose, AA6061 matrix composites were produced by pressure infiltration method using ceramic microparticles (TiB2 and B4C) and graphene nanoparticles (GNPs). The produced composites were first characterized by porosity measurement, X-ray diffraction (XRD), and scanning electron microscopy (SEM) analysis. Then, the wear behavior was examined under three different loads (20–40–60 N) with the reciprocating ball on the flat method in a dry environment. Specific wear-rates were calculated according to the Archard principle by measuring the depth and width of the traces after tests with a profilometer. Wearing mechanisms were determined with the help of optical and microstructure images. According to the obtained results, it was found that B4C + GNPs reinforced samples were more resistant to abrasion at low loads, but TiB2 + GNPs reinforced samples were higher at higher loads.

scholarly journals Photocatalytic activity of graphene oxide–TiO 2 thin films sensitized by natural dyes extracted from Bactris guineensis

2019 ◽  
Vol 6 (3) ◽  
pp. 181824 ◽  
Author(s):  
William Vallejo ◽  
Angie Rueda ◽  
Carlos Díaz-Uribe ◽  
Carlos Grande ◽  
Patricia Quintana
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Graphene Oxide ◽  
Photocatalytic Degradation ◽  
Photoelectron Spectroscopy ◽  
Chemical Characterization ◽  
Sem Analysis ◽  
Visible Range ◽  
X Ray ◽  
Natural Sensitizer

This study synthesized and characterized composites of graphene oxide and TiO 2 (GO–TiO 2 ). GO–TiO 2 thin films were deposited using the doctor blade technique. Subsequently, the thin films were sensitized with a natural dye extracted from a Colombian source ( Bactris guineensis ). Thermogravimetric analysis, X-ray diffraction, Raman spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance measurements were used for physico-chemical characterization. All the samples were polycrystalline in nature, and the diffraction signals corresponded to the TiO 2 anatase crystalline phase. Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR) verified the synthesis of composite thin films, and the SEM analysis confirmed the TiO 2 films morphological modification after the process of GO incorporation and sensitization. XPS results suggested a possibility of appearance of titanium (III) through the formation of oxygen vacancies (O v ). Furthermore, the optical results indicated that the presence of the natural sensitizer and GO improved the optical properties of TiO 2 in the visible range. Finally, the photocatalytic degradation of methylene blue was studied under visible irradiation in aqueous solution, and pseudo-first-order model was used to obtain kinetic information about photocatalytic degradation. These results indicated that the presence of GO has an important synergistic effect in conjunction with the natural sensitizer, reaching a photocatalytic yield of 33%.

Synthesis, Structural Analysis of Cadmium Sulphide Nanocrystallites

2019 ◽  
Vol 969 ◽  
pp. 169-174
Author(s):  
R. Sivanand ◽  
S. Chellammal ◽  
S. Manivannan
Keyword(s):  
Size Variation ◽  
Cadmium Sulphide ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Precipitation Method ◽  
Capping Agent ◽  
Energy Dispersive Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

In this paper, the effect of size variation of cadmium sulphide nanocrystallites which have been prepared by precipitation method is analyzed. These prepared samples were studied using X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Energy dispersive analysis of spectroscopy (EDAX) techniques. SEM analysis represents the morphological nature of prepared samples and EDAX indicates the confirmation of elements present in the sample. XRD analysis determines the size of the samples and identifies the structure using miller indices (h k l values) of the nanocrystallies matches with JCPDS. From the XRD analysis, the size variation which depends on dopant, capping agent are discussed and corresponding results are reported in this paper.

Histologic and Ultrastructural Analysis in a Case of Massive Failure of Zirconia Ball Head

2002 ◽  
Vol 12 (4) ◽  
pp. 388-393
Author(s):  
G. Maccauro ◽  
L. Petrella ◽  
L. Proietti ◽  
V. De Santis ◽  
C. Piconi
Keyword(s):  
Zirconium Oxide ◽  
Internal Surface ◽  
Giant Cells ◽  
Sem Analysis ◽  
Ultrastructural Analysis ◽  
Periprosthetic Tissue ◽  
X Ray ◽  
Internal Part ◽  
Scanning Electron

The in vivo histological and ultrastructural analysis of periprosthetic tissue collected at time of revision surgery for failure of a 28 mm yttria-tetragonal zirconium oxide polycrystal (YTZP) ball head, 2 years after implantation is reported. Histologic analysis showed Zirconia particles, rounded to polygonal ranging from 2μm to more than 10μm intra or extra cellular in a stroma without vessels with few giant cells. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX) showed the different shape from rounded to polygonal of Zirconia. SEM analysis of the internal part of Zirconia ball head showed the presence of different fracture lines especially in the internal surface

scholarly journals Brilliant angle-independent structural colours preserved in weevil scales from the Swiss Pleistocene

2020 ◽  
Vol 16 (4) ◽  
pp. 20200063
Author(s):  
Luke T. McDonald ◽  
Suresh Narayanan ◽  
Alec Sandy ◽  
Vinodkumar Saranathan ◽  
Maria E. McNamara
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
Three Dimensional ◽  
Far Field ◽  
Poor Knowledge ◽  
X Ray ◽  
Evolutionary Origins ◽  
X Ray Scattering ◽  
Colour Palette ◽  
Scanning Electron

Extant weevils exhibit a remarkable colour palette that ranges from muted monochromatic tones to rainbow-like iridescence, with the most vibrant colours produced by three-dimensional photonic nanostructures housed within cuticular scales. Although the optical properties of these nanostructures are well understood, their evolutionary history is not fully resolved, in part due to a poor knowledge of their fossil record. Here, we report three-dimensional photonic nanostructures preserved in brightly coloured scales of two weevils, belonging to the genus Phyllobius or Polydrusus , from the Pleistocene (16–10 ka) of Switzerland. The scales display vibrant blue, green and yellow hues that resemble those of extant Phyllobius/Polydrusus . Scanning electron microscopy and small-angle X-ray scattering analyses reveal that the subfossil scales possess a single-diamond photonic crystal nanostructure. In extant Phyllobius/Polydrusus , the near-angle-independent blue and green hues function primarily in crypsis. The preservation of far-field, angle-independent structural colours in the Swiss subfossil weevils and their likely function in substrate matching confirm the importance of investigating fossil and subfossil photonic nanostructures to understand the evolutionary origins and diversification of colours and associated behaviours (e.g. crypsis) in insects.

Sign in / Sign up

Export Citation Format

Share Document