scholarly journals Raman Spectroscopy and Statistical Analysis of the Silicate Species and Group Connectivity in Cesium Silicate Glass Forming System

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Armenak Osipov ◽  
Leyla Osipova ◽  
Rimma Zainullina
Keyword(s):  
Experimental Data ◽  
Raman Spectroscopy ◽  
Statistical Analysis ◽  
Raman Spectra ◽  
Dynamic Equilibrium ◽  
Structural Units ◽  
Melt Temperature ◽  
Deconvolution Analysis ◽  
Glass Forming ◽  
Increasing Temperature

The Raman spectra of x%Cs2O-(100 − x)%SiO2 (x=17, 22, 27, 33, and 37 mol%) glasses and melts were measured in the temperature range of 293 to 1553 K. The concentrations of the Qn species were calculated as a function of the composition and temperature based on the deconvolution analysis of the spectra. It was found that a dynamic equilibrium among structural units in the melts with x>17 mol% can be described by disproportionation reaction Q3⇔Q4+Q2. The enthalpy of this reaction was found to be equal to 32 ± 6, 43 ± 8, 56 ± 10, and 52 ± 9 for x=22, 27, 33, and 37 mol%, respectively. The nonideal entropy of mixing (ΔSmix) depends on the melt temperature and increases almost linearly with increasing temperature. The Qn, Q2–Q2, and Qn,ijkl distributions with x ranging from 0 to 55 mol% were modeled using experimental data for the concentrations of the Qn units.

Raman spectra of quasi-binary glasses As2S3−GeS2 doped with Er

2013 ◽  
Vol 37 (1) ◽  
pp. 33-38
Author(s):  
V. B. Petrović ◽  
I. O. Gúth ◽  
S. R. Lukić-Petrović
Keyword(s):  
Raman Spectroscopy ◽  
Rare Earth ◽  
Raman Spectra ◽  
Chalcogenide Glasses ◽  
Glass Matrix ◽  
Earth Element ◽  
Structural Units ◽  
Low Intensity ◽  
Quasibinary System ◽  
Different Origin

Abstract This work is concerned with a study of chalcogenide glasses doped with the rare-earth element erbium. The study was carried out on samples of the quasibinary system As2S3−GeS2 doped with erbium at the concentrations of 0, 0.01, 0.1, 0.5 and 1 at %. Raman spectroscopy was used to identify the presence of particular structural units in the glass matrix. The spectra of all the samples are characterized by an intense peak appearing as a consequence of the stretching of the As-S and Ge-S bonds. Further, several low-intensity peaks of different origin were also registered. These peaks arise due to the stretching of the bonds in the ring S8 and the bonds resulting from the existence of the ethane-type molecules (GeSn) in some of the samples. The peaks in the spectrum of the sample with the highest erbium content are characterized by the peaks that can be attributed to the stretching of the bond Er-S.

scholarly journals Using Raman Spectroscopy to Investigate the Molecular Level Characteristics of Endometriosis-=SUP=-*-=/SUP=-

2020 ◽  
Vol 128 (8) ◽  
pp. 1223
Author(s):  
Sevim Akyuz ◽  
Sefa Celik ◽  
Abdullah Taner Usta ◽  
Aysen E. Ozel ◽  
Gozde Yi lmaz -=SUP=-4-=/SUP=- ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Statistical Analysis ◽  
Raman Spectra ◽  
Young Women ◽  
Molecular Level ◽  
Multivariate Statistical ◽  
Tissue Samples ◽  
Linear Discriminant ◽  
Keywords Endometriosis

Endometriosis is a benign gynecologic disorder. It is particularly common among young women and may make pregnancy difficult. In this study molecular level characterization of endometriosis tissues were performed using Raman spectroscopy in combination with multivariate statistical analysis. Three hundred sixty-six Raman spectra recorded from different points of seventy two tissue samples, taken from the cyst walls of twelve patients were examined. Principle Component Analysis (PCA) followed by Linear Discriminant Analysis (LDA) were performed on the Raman data, and the samples were then classified into three groups; severe, moderate, and weak endometriosis. In the severe endometriosis group, the relative band intensities of DNA were increased. Moreover, increase in pyrrole moieties and kynurenine were seen. The results show that endometriosis severity correlates to increase in DNA concentration, and degradation of tryptophan due to increased indoleamine-pyrrole 2, 3-dioxygenase (IDO) activity, and an increase in kynurenine concentration and pyrrole intermediate. It is concluded that Raman spectroscopy is capable of providing a quick diagnosis, ahead of the pathology result being reported. Keywords: Endometriosis; Raman spectra, PCA-LDA analysis.

Submicron Simultaneous IR and Raman Spectroscopy (IR+Raman): Breakthrough Developments in Optical Photothermal IR (O-PTIR) Combined for Enhanced Failure Analysis

2019 ◽  
Author(s):  
Jay Anderson ◽  
Mustafa Kansiz ◽  
Michael Lo ◽  
Curtis Marcott
Keyword(s):  
Raman Spectroscopy ◽  
Failure Analysis ◽  
Data Quality ◽  
Raman Spectra ◽  
Spatial Resolution ◽  
Far Field ◽  
Field Mode ◽  
Microscopic Scale ◽  
Analytical Tools ◽  
Ir And Raman

Abstract Failure analysis of organics at the microscopic scale is an increasingly important requirement, with traditional analytical tools such as FTIR and Raman microscopy, having significant limitations in either spatial resolution or data quality. We introduce here a new method of obtaining Infrared microspectroscopic information, at the submicron level in reflection (far-field) mode, called Optical-Photothermal Infrared (O-PTIR) spectroscopy, that can also generate simultaneous Raman spectra, from the same spot, at the same time and with the same spatial resolution. This novel combination of these two correlative techniques can be considered to be complimentary and confirmatory, in which the IR confirms the Raman result and vice-versa, to yield more accurate and therefore more confident organic unknowns analysis.

scholarly journals Quantitative and Qualitative Analysis of Some Inorganic Compounds by Raman Spectroscopy

1994 ◽  
Vol 48 (7) ◽  
pp. 875-883 ◽  
Author(s):  
Daniel R. Lombardi ◽  
Chao Wang ◽  
Bin Sun ◽  
Augustus W. Fountain ◽  
Thomas J. Vickers ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Raman Spectroscopy ◽  
Qualitative Analysis ◽  
Raman Spectra ◽  
Solid Phase ◽  
Inorganic Compounds ◽  
Core Material ◽  
Storage Tanks ◽  
Hanford Site ◽  
Sampling Probe

Raman spectra have been measured for a number of nitrates, nitrites, sulfates, ferrocyanides, and ferricyanides, both in the solid phase and in aqueous solution. Accurate locations of peak maxima are given. Limits of detection for some of the compounds are given for solutions and for solid mixtures in NaNO3. Preliminary measurements have been made on core material recovered from the storage tanks on the Hanford site in Richland, Washington. Representative spectra are presented, showing that it is possible to observe responses of individual components from measurements made directly on untreated cores, with the use of a fiberoptic sampling probe.

scholarly journals Indication of high lipid content in epithelial-mesenchymal transitions of breast tissues

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Siti Norbaini Sabtu ◽  
S. F. Abdul Sani ◽  
L. M. Looi ◽  
S. F. Chiew ◽  
Dharini Pathmanathan ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Raman Spectroscopy ◽  
Multivariate Analysis ◽  
Nucleic Acids ◽  
Raman Spectra ◽  
Cancer Progression ◽  
Component Analysis ◽  
Breast Cancer Tissue ◽  
Metabolic Changes ◽  
Cancer Tissue

AbstractThe epithelial-mesenchymal transition (EMT) is a crucial process in cancer progression and metastasis. Study of metabolic changes during the EMT process is important in seeking to understand the biochemical changes associated with cancer progression, not least in scoping for therapeutic strategies aimed at targeting EMT. Due to the potential for high sensitivity and specificity, Raman spectroscopy was used here to study the metabolic changes associated with EMT in human breast cancer tissue. For Raman spectroscopy measurements, tissue from 23 patients were collected, comprising non-lesional, EMT and non-EMT formalin-fixed and paraffin embedded breast cancer samples. Analysis was made in the fingerprint Raman spectra region (600–1800 cm−1) best associated with cancer progression biochemical changes in lipid, protein and nucleic acids. The ANOVA test followed by the Tukey’s multiple comparisons test were conducted to see if there existed differences between non-lesional, EMT and non-EMT breast tissue for Raman spectroscopy measurements. Results revealed that significant differences were evident in terms of intensity between the non-lesional and EMT samples, as well as the EMT and non-EMT samples. Multivariate analysis involving independent component analysis, Principal component analysis and non-negative least square were used to analyse the Raman spectra data. The results show significant differences between EMT and non-EMT cancers in lipid, protein, and nucleic acids. This study demonstrated the capability of Raman spectroscopy supported by multivariate analysis in analysing metabolic changes in EMT breast cancer tissue.

scholarly journals Combining Mechanistic Modeling and Raman Spectroscopy for Monitoring Antibody Chromatographic Purification

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 683 ◽  
Author(s):  
Feidl ◽  
Garbellini ◽  
Luna ◽  
Vogg ◽  
Souquet ◽  
...  
Keyword(s):  
Experimental Data ◽  
Raman Spectroscopy ◽  
Estimation Procedure ◽  
Mechanistic Modeling ◽  
Spectroscopic Techniques ◽  
Chromatographic Purification ◽  
On Line ◽  
Filter Approach ◽  
Underlying Mechanisms ◽  
Combining Information

Chromatography is widely used in biotherapeutics manufacturing, and the corresponding underlying mechanisms are well understood. To enable process control and automation, spectroscopic techniques are very convenient as on-line sensors, but their application is often limited by their sensitivity. In this work, we investigate the implementation of Raman spectroscopy to monitor monoclonal antibody (mAb) breakthrough (BT) curves in chromatographic operations with a low titer harvest. A state estimation procedure is developed by combining information coming from a lumped kinetic model (LKM) and a Raman analyzer in the frame of an extended Kalman filter approach (EKF). A comparison with suitable experimental data shows that this approach allows for the obtainment of reliable estimates of antibody concentrations with reduced noise and increased robustness.

Quantitative Analysis of Raman Spectra in Si/SiGe Nanostructures

2013 ◽  
Vol 1510 ◽  
Author(s):  
Selina Mala ◽  
Leonid Tsybeskov ◽  
Jean-Marc Baribeau ◽  
Xiaohua Wu ◽  
David J. Lockwood
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Quantitative Analysis ◽  
Raman Spectra ◽  
Instrumental Response ◽  
Sample Surface ◽  
Stray Light ◽  
Raman Signal ◽  
Longitudinal Acoustic ◽  
Local Sample

ABSTRACTWe present comprehensive quantitative analysis of Raman spectra in two-(Si/SiGe superlattices) and three-(Si/SiGe cluster multilayers) dimensional nanostructures. We find that the Raman spectra baseline is due to the sample surface imperfection and instrumental response associated with the stray light. The Raman signal intensity is analyzed, and Ge composition is calculated and compared with the experimental data. The local sample temperature and thermal conductivity are calculated, and the spectrum of longitudinal acoustic phonons is explained.

Application of Raman Spectroscopy to the Study of Adsorption Effects at Liquid-Solid Interfaces

1982 ◽  
Vol 36 (4) ◽  
pp. 471-473 ◽  
Author(s):  
Klaus Witke
Keyword(s):  
Raman Spectroscopy ◽  
Carbon Tetrachloride ◽  
Adsorption Isotherm ◽  
Minimal Surface ◽  
Linear Relationship ◽  
Surface Area ◽  
Long Range ◽  
Raman Spectra ◽  
Sample Cell ◽  
Minimal Surface Area

A sample cell for investigating suspensions or emulsions by Raman spectroscopy in the optically favorable 90° scattering arrangement is described. The Raman spectra of pyridine in a suspension of Aerosil 200 in carbon tetrachloride are recorded. The adsorption isotherm of pyridine is determined from the intensities of the Raman lines at 1008 and 990 cm−1. Over a long range of coverage a linear relationship exists between reciprocal concentrations of chemisorbed and dissolved molecules. The minimal surface area that is occupied by a chemisorbed molecule is determined to be approximately 0.75 nm2.

scholarly journals Raman Spectra of Nanodiamonds: New Treatment Procedure Directed for Improved Raman Signal Marker Detection

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Raoul R. Nigmatullin ◽  
Dumitru Baleanu ◽  
Diana Povarova ◽  
Numan Salah ◽  
Sami S. Habib ◽  
...  
Keyword(s):  
Raman Spectra ◽  
High Refractive Index ◽  
Spectroscopic Studies ◽  
Raman Signal ◽  
Heating Rates ◽  
Inert Core ◽  
Optimal Linear ◽  
Linear Smoothing ◽  
New Treatment ◽  
Increasing Temperature

Detonation nanodiamonds (NDs) have shown to be promising agents in several industries, ranging from electronic to biomedical applications. These NDs are characterized by small particle size ranging from 3 to 6 nm, while having a reactive surface and a stable inert core. Nanodiamonds can exhibit novel intrinsic properties such as fluorescence, high refractive index, and unique Raman signal making them very attractive imaging agents. In this work, we used several nanodiamond preparations for Raman spectroscopic studies. We exposed these nanodiamonds to increasing temperature treatments at constant heating rates (425–575°C) aiding graphite release. We wanted to correlate changes in the nanodiamond surface and properties with Raman signal which could be used as adetection marker. These observations would hold potential utility in biomedical imaging applications. First, the procedure of optimal linear smoothing was applied successfully to eliminate the high-frequency fluctuations and to extract the smoothed Raman spectra. After that we applied the secondary Fourier transform as the fitting function based on some significant set of frequencies. The remnant noise was described in terms of the beta-distribution function. We expect this data treatment to provide better results in biomolecule tracking using nanodiamond base Raman labeling.

Raman Spectra of Ion Implanted Graphite

1981 ◽  
Vol 7 ◽  
Author(s):  
B.S. Elman ◽  
H. Mazurek ◽  
M.S. Dresselhaus ◽  
G. Dresselhaus
Keyword(s):  
Raman Spectroscopy ◽  
Ion Implantation ◽  
Raman Spectra ◽  
Annealing Temperature ◽  
Annealing Process ◽  
Lattice Order ◽  
Annealing Temperatures ◽  
High Fluences ◽  
Lattice Damage ◽  
The Way

ABSTRACTRaman spectroscopy is used in a variety of ways to monitor different aspects of the lattice damage caused by ion implantation into graphite. Particular attention is given to the use of Raman spectroscopy to monitor the restoration of lattice order by the annealing process, which depends critically on the annealing temperature and on the extent of the original lattice damage. At low fluences the highly disordered region is localized in the implanted region and relatively low annealing temperatures are required, compared with the implantation at high fluences where the highly disordered region extends all the way to the surface. At high fluences, annealing temperatures comparable to those required for the graphitization of carbons are necessary to fully restore lattice order.

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