scholarly journals Microscopic And Spectroscopic Research Of The MWCNTs-Re Nanocomposites

2015 ◽  
Vol 60 (3) ◽  
pp. 2047-2052 ◽  
Author(s):  
A.D. Dobrzańska-Danikiewicz ◽  
W. Wolany ◽  
D. Cichocki ◽  
D. Łukowiec
Keyword(s):  
Raman Spectroscopy ◽  
Comparative Analysis ◽  
High Temperature ◽  
Manufacturing Process ◽  
Covalent Modification ◽  
Band Intensity ◽  
Structural Defects ◽  
Forms Of Carbon

Abstract The combination of TEM research and Raman spectroscopy to characterization of MWNTs-Re nanocomposites gives a new notion about the structure and quality of materials obtained. TEM studies indicate that the functionalization method significantly influences the morphology of obtained MWCNTs-Re nanocomposites. Due to the specific spectrum recorded for the MWCNTs they can be distinguished from other forms of carbon, furthermore comparative analysis of the results at different stages of the manufacturing process confirms the covalent modification of the MWCNTs structure. The D-band intensity compared to the G-band intensity provides valuable information about the quality of the sample, in particular indicates the existence of contamination and/or the presence of structural defects. Preliminary results suggest that the high-temperature manufacturing process of MWCNTs-Re nanocomposite improves the quality of the carbon material intended for the experiment.

Characterization of Structural Quality of Bonded Silicon-On-Insulator Wafers by Spectroscopic Ellipsometry and Raman Spectroscopy

2004 ◽  
Vol 809 ◽  
Author(s):  
N. V. Nguyen ◽  
J. E. Maslar ◽  
Jin-Yong Kim ◽  
Jin-Ping Han ◽  
Jin-Won Park ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Dielectric Function ◽  
Spectroscopic Ellipsometry ◽  
Crystalline Silicon ◽  
Silicon On Insulator ◽  
Structural Defects ◽  
Structural Quality ◽  
Ellipsometry Data

ABSTRACTThe crystalline quality of bonded Silicon-On-Insulator (SOI) wafers were examined by spectroscopic ellipsometry and Raman spectroscopy. Both techniques detect slight structural defects in the SOI layer. If a pure crystalline silicon dielectric function is assumed for the SOI layer, the spectroscopic ellipsometry data fitting yields an unacceptably large discrepancy between the experimental and modeled data. The best fits for all the samples result in a dielectric function of the SOI layer that consists of a physical mixture of crystalline silicon and about 4 % to 7 % of amorphous silicon. Using such a mixture indicates that there are still some defects in the SOI layer when compared with the high-quality bulk crystalline silicon. This observation is further supported by Raman spectroscopy measurements. The Raman spectra of all SOI samples exhibit a feature at about 495 cm−1 that is not observed in the crystalline silicon spectrum. Features similar to the 495 cm−1 feature have been reported in the literature and attributed to dislocations or faults in the silicon lattice.

scholarly journals Chemical and sensory characterization of plum spirits obtained from cultivar Cacanska Rodna and its parent cultivars

2019 ◽  
Vol 84 (12) ◽  
pp. 1381-1390 ◽  
Author(s):  
Branko Popovic ◽  
Olga Mitrovic ◽  
Aleksandar Leposavic ◽  
Svetlana Paunovic ◽  
Darko Jevremovic ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Ethyl Acetate ◽  
Volatile Compounds ◽  
Sensory Quality ◽  
Alcoholic Fermentation ◽  
Processing Method ◽  
Hexanoic Acid ◽  
Sensory Characteristics

During the two-year research, a comparative analysis of the contents of 24 major volatile compounds and sensory characteristics of the plum spirits produced by spontaneous alcoholic fermentation of the plum mashes with or without stones from cultivar Cacanska Rodna and its parent cultivars ? Stanley and Pozegaca were carried out. The plum spirits obtained from Cacanska Rodna cultivar contain lower amounts of methanol, 1-hexanol, ethyl acetate and acetaldehyde and higher amounts of 3-methyl-1-butanol and 2-phenylethanol than the spirits from its parent cultivars. Contents of 1-propanol, 1-butanol and hexanoic acid in the spirits obtained from Cacanska Rodna cultivar were lower than the contents in the spirits from Pozegaca and higher than those in the spirits obtained from Stanley. The sensory quality of plum spirits, in addition to the cultivar, has been significantly influenced by the presence of stones in the mash during processing of plums into spirits. In processing plums with stones, the best-graded plum spirit was from Pozegaca (17.88), whereas in processing without stones, the best was Cacanska Rodna spirit (17.78). The spirits obtained from Stanley cultivar had the lowest sensory grades regardless of the processing method.

PREPARATION AND CHARACTERIZATION OF CaZrO3COATING ON GRAPHITE FOR TiNi ALLOY MELTING

2019 ◽  
Vol 27 (05) ◽  
pp. 1950152
Author(s):  
BIN ZHAN ◽  
YUE ZHANG ◽  
YUNFENG XIAO ◽  
CAIFEN WANG ◽  
XIANGDONG ZHANG
Keyword(s):  
High Temperature ◽  
Color Change ◽  
Raw Material ◽  
Flame Spraying ◽  
Tini Alloy ◽  
High Temperature Process ◽  
Calcium Metal ◽  
Melting Material

Graphite is a favorable melting material of TiNi alloy. In order to reduce the carbon increment during high temperature process, the protective CaZrO3 coating has been prepared using different methods. First, CaZrO3 powder was synthesized via solid-state reaction using calcium metal as raw material. The coating on graphite was prepared by flame spraying, plasma spraying and dipping sintering, then it was observed and characterized. The results show that the apparent quality of the obtained coating is intactness. Here, the spraying coating is composition uniform and structure compact; the dipping coating exhibits an obvious color change and presents the typical porous structure.

Raman Spectroscopy of Graphitic Foams

2004 ◽  
Vol 851 ◽  
Author(s):  
Eduardo B. Barros ◽  
Nasser S. Demir ◽  
Antonio G. Souza Filho ◽  
Josué Medes Filho ◽  
Ado Jorio ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Raman Spectroscopy ◽  
National Laboratory ◽  
Weight Ratio ◽  
Spectroscopy Study ◽  
Oak Ridge ◽  
Very High ◽  
Graphitic Foam

ABSTRACTTo better understand the very high thermal conductivity to weight ratio of the graphitic foams recently developed at the Oak Ridge National Laboratory, a Raman spectroscopy study was performed. It was also shown that the Raman scattering can be useful for the characterization of the graphitic foam, being able to evaluate the quality of the samples with respect to the density and location of lattice defects.

scholarly journals The Influence of Angstrom-Scale Roughness on the Laser-Induced Damage Threshold of Single-Crystal ZnGeP2

Crystals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 83
Author(s):  
Nikolai Yudin ◽  
Andrei Khudoley ◽  
Mikhail Zinoviev ◽  
Sergey Podzvalov ◽  
Elena Slyunko ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Single Crystal ◽  
Magnetic Particles ◽  
Damage Threshold ◽  
Structural Defects ◽  
Physical Limitations ◽  
Laser Induced Damage ◽  
Crystal Volume

Magnetorheological processing was applied to polish the working surfaces of single-crystal ZnGeP2, in which a non-aqueous liquid with the magnetic particles of carbonyl iron with the addition of nanodiamonds was used. Samples of a single-crystal ZnGeP2 with an Angstrom level of surface roughness were received. The use of magnetorheological polish allowed the more accurate characterization of the possible structural defects that emerged on the surface of a single crystal and had a size of ~0.5–1.5 μm. The laser-induced damage threshold (LIDT) value at the indicated orders of magnitude of the surface roughness parameters was determined not by the quality of polishing, but by the number of point depressions caused by the physical limitations of the structural configuration of the crystal volume. These results are in good agreement with the assumption made about a significant effect of the concentration of dislocations in a ZnGeP2 crystal on LIDT.

Raman scattering characterization of (100) and (111) oriented diamond films grown in the same run by hot filament chemical vapor deposition

1994 ◽  
Vol 9 (11) ◽  
pp. 2839-2844 ◽  
Author(s):  
G. Popovici ◽  
S. Khasawinah ◽  
T. Sung ◽  
M.A. Prelas ◽  
B.V. Spitsyn ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Diamond Film ◽  
Vapor Deposition ◽  
Diamond Films ◽  
Chemical Deposition ◽  
Chemical Vapor ◽  
Infrared Excitation ◽  
Hot Filament

The crystalline quality of a diamond film with two different preferential orientations (100) and (111), obtained in the same run by hot filament chemical deposition, has been studied. The quality of the film determined by Raman spectroscopy measurements was found to be nearly the same for both orientations. The second order Raman spectrum for diamond film was observed by using an infrared excitation.

scholarly journals Study of the Degree of Cure through Thermal Analysis and Raman Spectroscopy in Composite-Forming Processes

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3991 ◽  
Author(s):  
Juan A. García-Manrique ◽  
Bernabé Marí ◽  
Amparo Ribes-Greus ◽  
Llúcia Monreal ◽  
Roberto Teruel ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Thermal Characterization ◽  
Degree Of Polymerization ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Degree Of Cure ◽  
Composite Forming ◽  
Out Of Autoclave

The curing of composite materials is one of the parameters that most affects their mechanical behavior. The inspection methods used do not always allow a correct characterization of the curing state of the thermosetting resins. In this work, Raman spectroscopy technology is used for measuring the degree of cure. The results are compared with conventional thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and scanning electron microscope (SEM). Carbon fiber specimens manufactured with technologies out of autoclave (OoA) have been used, with an epoxy system Prepreg System, SE 84LV. The results obtained with Raman technology show that it is possible to verify the degree of polymerization, and the information is complementary from classical thermal characterization techniques such as TGA and DSC; thus, it is possible to have greater control in curing and improving the quality of the manufactured parts.

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