scholarly journals Micro-Raman Spectroscopy Assessment of Chemical Compounds of Mantle Clinopyroxenes

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1084
Author(s):  
Anastasiya D. Kalugina ◽  
Dmitry A. Zedgenizov
Keyword(s):  
Raman Spectroscopy ◽  
Chemical Composition ◽  
Chemical Compounds ◽  
Peak Position ◽  
Mantle Xenoliths ◽  
Wide Range ◽  
Stretching Vibration ◽  
Raman Modes ◽  
Non Destructive ◽  
Heterovalent Isomorphism

The composition of clinopyroxenes is indicative for chemical and physical properties of mantle substrates. In this study, we present the results of Raman spectroscopy examination of clinopyroxene inclusions in natural diamonds (n = 51) and clinopyroxenes from mantle xenoliths of peridotites and eclogites from kimberlites (n = 28). The chemical composition of studied clinopyroxenes shows wide variations indicating their origin in different mantle lithologies. All clinopyroxenes have intense Raman modes corresponding to metal-oxygen translation (~300–500 cm−1), stretching vibrations of bridging O-Si-Obr (ν11~670 cm−1), and nonbridging atoms O-Si-Onbr (ν16~1000 cm−1). The peak position of the stretching vibration mode (ν11) for the studied clinopyroxenes varies in a wide range (23 cm−1) and generally correlates with their chemical composition and reflects the diopside-jadeite heterovalent isomorphism. These correlations may be used for rough estimation of these compounds using the non-destructive Raman spectroscopy technique.

scholarly journals Raman spectroscopy as a non-destructive tool to determine the chemical composition of urinary sediments

2021 ◽  
Vol 24 (S2) ◽  
pp. 1-10
Author(s):  
Sandra Tamosaityte ◽  
Milda Pucetaite ◽  
Arunas Zelvys ◽  
Sonata Varvuolyte ◽  
Vaiva Hendrixson ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Chemical Composition ◽  
Non Destructive

Archaeological investigations (archaeometry)

2018 ◽  
Vol 3 (9) ◽  
Author(s):  
Anastasia Rousaki ◽  
Luc Moens ◽  
Peter Vandenabeele
Keyword(s):  
Raman Spectroscopy ◽  
Organic Materials ◽  
Research Area ◽  
Fundamental Interest ◽  
Non Invasive ◽  
Wide Range ◽  
Research Questions ◽  
Non Destructive ◽  
Speed Of Analysis ◽  
Straightforward Interpretation

Abstract Archaeometry is the research area on the edge between humanities and natural sciences: it uses and optimises methods from chemistry, spectroscopy, physics, biology, etc. to help answering research questions from humanities. In general, these objects are investigated for several reasons. Besides the fundamental interest to know about the materials that were used in the past, the study of artefacts can support their preservation, either by helping to select optimal storage or display conditions, either by investigating decay pathways and suggesting solutions. Other reasons for art analysis include provenance studies, dating the artefact or identifying forgeries. Since several years, Raman spectroscopy is increasingly applied for the investigation of objects of art or archaeology. The technique is well-appreciated for the limited (or even absent) sample preparation, the relative straightforward interpretation of the spectra (by fingerprinting - comparing them against a database of reference pigments) and its speed of analysis. Moreover, the small spectral footprint – allowing to record a molecular spectrum of particles down to 1 µm, the typical size of pigment grains – is certainly a positive property of the technique. Raman spectroscopy can be considered as rather versatile, as inorganic as well as organic materials can be studied, and as the technique can gather information on crystalline as well as on non-crystalline phases. As a consequence, Raman spectroscopy can be used to study antique objects and twentieth-century synthetic (organic) materials – illustrating the wide range of applications. Finally, the technique is as non-destructive, provided the laser power is kept sufficiently low not to damage the artwork. In literature, the terms “non-invasive” and “non-destructive” are used, where the first term means that no sampling is involved, and the latter term indicates that no sample is taken or that during analysis the sample is not consumed (destroyed) and remains available for further analysis.

Vibrational Raman Scattering from high TC single Crystals

1987 ◽  
Vol 99 ◽  
Author(s):  
D. M. Krol ◽  
M. Stavola ◽  
L. F. Schneemeyer ◽  
J. V. Waszczak ◽  
W. Weber
Keyword(s):  
Chemical Composition ◽  
Raman Scattering ◽  
Single Crystals ◽  
Raman Spectra ◽  
Peak Position ◽  
High Tc ◽  
Stretching Vibration ◽  
Polarized Raman ◽  
Axial Stretching

ABSTRACTPolarized Raman spectra have been measured on single crystals of the high Tc materials A2BCu3Ox with A=Ba and Sr, B=Y and La and 6<x<7. The dependence of the 500 cm-i peak position (αzz)on chemical composition is in agreement with its assignment to the O(1) axial stretching vibration. The intensity of the 600 cm1 band, which has been ascribed to a defect induced Cu-O mode, strongly depends on the crystal preparation and resulting purity.

scholarly journals Chemical Composition of the Essential Oils of Three Ocimum basilicum L. Cultivars from Serbia

2018 ◽  
Vol 47 (2) ◽  
pp. 347-351 ◽  
Author(s):  
Aleksandra S. ILIĆ ◽  
Mališa P. ANTIĆ ◽  
Slavica C. JELAČIĆ ◽  
Tatjana M. ŠOLEVIĆ KNUDSEN
Keyword(s):  
Chemical Composition ◽  
Essential Oils ◽  
Biological Activities ◽  
Chemical Compounds ◽  
Biologically Active ◽  
Pharmaceutical Chemical ◽  
Oxygenated Monoterpenes ◽  
Wide Range ◽  
Sesquiterpene Hydrocarbons ◽  
Complex Chemical Composition

Basil essential oil (BEO) contains a wide range of chemical compounds whose content may vary depending on chemotypes, environmental conditions, agronomic techniques and particularly the origin of the plant. In our present study, essential oils (EOs) were isolated by hydrodistillation method from dry herbs of three basil cultivars and analyzed by GC-FID and GC-MS. Two of the tested cultivars belong to sweet basil group (B1 and B2) while the third one was large leafed ʽGenovese’ basil (B3). EO content in the dry herb was 0.65%, 0.41% and 0.62% respectively. The main classes of compounds of B1EO and B3EO were sesquiterpene hydrocarbons (38.39% and 37.95%), oxygenated monoterpenes (25.44% and 28.04%) and phenylpropanoids (17.43% and 15.71%). The main constituents of both EOs were monoterpene alcohol linalool (13.68% and 15.38%), phenoyl derivate eugenol (10.83% and 8.97%) and sesquiterpene hydrocarbon α-bergamotene (8.12% and 9.25%). In both EOs, epi-bicyclosesquiphellandrene was detected in considerable amount (7.03% and 8.07%). The most abundant compound classes in B2EO were oxygenated monoterpenes (52.07%), sesquiterpene hydrocarbons (24.27%) and phenylpropanoids (10.95%). Linalool was the dominant compound (40.97%), followed by epi-bicyclosesquiphellandrene (8.70%) and methyl chavicol (7.92%). The results showed complex chemical composition of BEOs and pointed out the presence of biologically active compounds of importance for different branches of the pharmaceutical, chemical and food industry. Although there are differences in the chemical composition of the BEOs, the obtained results show that all of the tested cultivars are rich in compounds which are responsible for biological activities. 

scholarly journals Microcavity Enhanced Raman Spectroscopy of Fullerene C60 Bucky Balls

Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1470 ◽  
Author(s):  
Vinayaka H. Damle ◽  
Miri Sinwani ◽  
Hagit Aviv ◽  
Yaakov R. Tischler
Keyword(s):  
Raman Spectroscopy ◽  
Low Cost ◽  
Spectroscopic Characterization ◽  
Low Energy ◽  
Cavity Resonance ◽  
Raman Spectroscopic ◽  
Raman Enhancement ◽  
Raman Modes ◽  
Selective Enhancement ◽  
Non Destructive

Raman spectroscopy is a widely used characterization technique in material science. It is a non-destructive tool with relatively simple instrumentation, and provides intrinsic qualitative information of analytes by probing their vibrational modes. In many cases, Raman enhancement is essential for detecting low-intensity signals in high-noise environments, spectrally unresolved features, and hidden modes. Here we present optical and Raman spectroscopic characterization of fullerene C 60 in a gold microcavity. The fabrication of single-layered gold mirrors is facile, low cost and direct but was proven to give considerably significant enhancement. The findings of this work demonstrate the cavity resonance as a powerful tool in obtaining tunability over individual peak for selective enhancement in the tuned spectral range. The PL of the material within the cavity has demonstrated a red shift assumed to be caused by the low-energy transitions. These transitions are induced by virtual low-energy states generated by the cavity. We further observe that adopting this principle enables resolution of active Raman modes that until now were unobserved. Finally, we assigned the new experimentally observed modes to the corresponding motions calculated by DFT.

PATH-43. RAMAN SPECTROSCOPY AS A TOOL IN NEUROSURGERY

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi125-vi125
Author(s):  
Felix Kleine Borgmann ◽  
Gilbert Georg Klamminger ◽  
Laurent Mombaerts ◽  
Karoline Klein ◽  
Finn Jelke ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Tumor Tissue ◽  
Central Nervous System Lymphoma ◽  
Surrounding Tissue ◽  
Sample Analysis ◽  
Tissue Identification ◽  
Important Differential Diagnosis ◽  
Wide Range ◽  
Neuronavigation System ◽  
Non Destructive

Abstract BACKGROUND Raman Spectra have been shown to be sufficiently characteristic to their samples of origin that they can be used in a wide range of applications including distinction of intracranial tumors. While not replacing pathological analysis, the advantage of non-destructive sample analysis and extremely fast feedback make this technique an interesting tool for surgical use. METHODS We sampled intractanial tumors from more than 300 patients at the Centre Hospitalier Luxembourg over a period of three years and compared the spectra of different tumor entities, different tumor subregions and healthy surrounding tissue. We created machine-learning based classifiers that include tissue identification as well as diagnostics. RESULTS To this end, we solved several classes in the intracranial tumor classification, and developed classifiers to distinguish primary central nervous system lymphoma from glioblastoma, which is an important differential diagnosis, as well as meningioma from the surrounding healthy dura mater for identification of tumor tissue. Within glioblastoma, we resolve necrotic, vital tumor tissue and peritumoral infiltration zone.We are currently developing a multi-class classifier incorporating all tissue types measured. CONCLUSIONS Raman Spectroscopy has the potential to aid the surgeon in the surgery theater by providing a quick assessment of the tissue analyzed with regards to both tumor identity and tumor margin identification. Once a reliable classifier based on sufficient patient samples is developed, this may even be integrated into a surgical microscope or a neuronavigation system.

Luminescence from individual dislocations in II-VI and III-V semiconductors

1991 ◽  
Vol 49 ◽  
pp. 834-835
Author(s):  
J W Steeds
Keyword(s):  
Group Iv ◽  
Luminescence Properties ◽  
Carrier Recombination ◽  
Transmission Electron ◽  
Wide Range ◽  
Basic Physics ◽  
Semiconducting Compounds ◽  
Diamond Group ◽  
Non Destructive ◽  
Technological Significance

There is a wide range of experimental results related to dislocations in diamond, group IV, II-VI, III-V semiconducting compounds, but few of these come from isolated, well-characterized individual dislocations. We are here concerned with only those results obtained in a transmission electron microscope so that the dislocations responsible were individually imaged. The luminescence properties of the dislocations were studied by cathodoluminescence performed at low temperatures (~30K) achieved by liquid helium cooling. Both spectra and monochromatic cathodoluminescence images have been obtained, in some cases as a function of temperature.There are two aspects of this work. One is mainly of technological significance. By understanding the luminescence properties of dislocations in epitaxial structures, future non-destructive evaluation will be enhanced. The second aim is to arrive at a good detailed understanding of the basic physics associated with carrier recombination near dislocations as revealed by local luminescence properties.

Therapeutic Properties of Several Chemical Compounds from Salvia officinalis L. in Alzheimer’s Disease

2020 ◽  
Vol 21 ◽  
Author(s):  
Georgiana Uță ◽  
Denisa Ștefania Manolescu ◽  
Speranța Avram
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Side Effects ◽  
Chemical Compounds ◽  
Natural Compounds ◽  
Salvia Officinalis ◽  
Chemical Structures ◽  
In Silico Studies ◽  
Wide Range ◽  
Salvia Officinalis L

Background.: Currently, the pharmacological management in Alzheimer's disease is based on several chemical structures, represented by acetylcholinesterase and N-methyl-D-aspartate (NMDA) receptor ligands, with still unclear molecular mechanisms, but severe side effects. For this reason, a challenge for Alzheimer's disease treatment remains to identify new drugs with reduced side effects. Recently, the natural compounds, in particular certain chemical compounds identified in the essential oil of peppermint, sage, grapes, sea buckthorn, have increased interest as possible therapeutics. Objectives.: In this paper, we have summarized data from the recent literature, on several chemical compounds extracted from Salvia officinalis L., with therapeutic potential in Alzheimer's disease. Methods.: In addition to the wide range of experimental methods performed in vivo and in vitro, also we presented some in silico studies of medicinal compounds. Results. Through this mini-review, we present the latest information regarding the therapeutic characteristics of natural compounds isolated from Salvia officinalis L. in Alzheimer's disease. Conclusion.: Thus, based on the information presented, we can say that phytotherapy is a reliable therapeutic method in a neurodegenerative disease.

scholarly journals Raman Spectroscopy Investigation of Graphene Oxide Reduction by Laser Scribing

2021 ◽  
Vol 7 (2) ◽  
pp. 48
Author(s):  
Vittorio Scardaci ◽  
Giuseppe Compagnini
Keyword(s):  
Raman Spectroscopy ◽  
Graphene Oxide ◽  
Reduce Graphene Oxide ◽  
Oxide Reduction ◽  
Material Parameters ◽  
Laser Scribing ◽  
Wide Range ◽  
Scan Speed ◽  
Laser Reduction

Laser scribing has been proposed as a fast and easy tool to reduce graphene oxide (GO) for a wide range of applications. Here, we investigate laser reduction of GO under a range of processing and material parameters, such as laser scan speed, number of laser passes, and material coverage. We use Raman spectroscopy for the characterization of the obtained materials. We demonstrate that laser scan speed is the most influential parameter, as a slower scan speed yields poor GO reduction. The number of laser passes is influential where the material coverage is higher, producing a significant improvement of GO reduction on a second pass. Material coverage is the least influential parameter, as it affects GO reduction only under restricted conditions.

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