Statistical approaches in the analysis of in situ thermo‐Raman spectroscopic data for gypsum as a basis for studying dehydration and phase transformations in crystalline hydrates

2021 ◽  
Author(s):  
Elizaveta A. Pankrushina ◽  
Sergey L. Votyakov ◽  
Yuliya V. Shchapova
Keyword(s):  
Phase Transformations ◽  
Spectroscopic Data ◽  
Raman Spectroscopic ◽  
Statistical Approaches ◽  
Crystalline Hydrates

The use of transmission and analytical electron microscopy in studying reactions and phase transformations in thin film

1993 ◽  
Vol 51 ◽  
pp. 842-843
Author(s):  
K. Barmak
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transformations ◽  
Analytical Electron Microscopy ◽  
Ex Situ ◽  
Multilayer Thin Films ◽  
Absolute Concentration ◽  
Analytical Electron ◽  
Deposition Step

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.

scholarly journals Microwave induced in situ amorphisation facilitated by crystalline hydrates

2021 ◽  
pp. 105858
Author(s):  
Tobias Palle Holm ◽  
Matthias Manne Knopp ◽  
Korbinian Löbmann ◽  
Ragna Berthelsen
Keyword(s):  
Crystalline Hydrates

scholarly journals Synthesis and Characterisation of Molecular Polarised-Covalent Thorium-Rhenium and -Ruthenium Bonds

Inorganics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 30
Author(s):  
Joseph P. A. Ostrowski ◽  
Ashley J. Wooles ◽  
Stephen T. Liddle
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Spectroscopic Data ◽  
Raman Spectroscopic ◽  
Ir And Raman ◽  
Alkane Elimination

Separate reactions of [Th{N(CH2CH2NSiMe2But)2(CH2CH2NSi(Me)(But)(μ-CH2)]2 (1) with [Re(η5-C5H5)2(H)] (2) or [Ru(η5-C5H5)(H)(CO)2] (3) produced, by alkane elimination, [Th(TrenDMBS)Re(η5-C5H5)2] (ThRe, TrenDMBS = {N(CH2CH2NSiMe2But)3}3-), and [Th(TrenDMBS)Ru(η5-C5H5)(CO)2] (ThRu), which were isolated in crystalline yields of 71% and 62%, respectively. Complex ThRe is the first example of a molecular Th-Re bond to be structurally characterised, and ThRu is only the second example of a structurally authenticated Th-Ru bond. By comparison to isostructural U-analogues, quantum chemical calculations, which are validated by IR and Raman spectroscopic data, suggest that the Th-Re and Th-Ru bonds reported here are more ionic than the corresponding U-Re and U-Ru bonds.

Zirconium phase transformations observed by “in-situ” XRD analysis

Vacuum ◽  
2012 ◽  
Vol 86 (6) ◽  
pp. 785-788 ◽  
Author(s):  
Jan Riha ◽  
Pavol Sutta ◽  
Andrej Vincze ◽  
Rostislav Medlin
Keyword(s):  
Phase Transformations ◽  
Xrd Analysis ◽  
In Situ Xrd

An in situ Raman spectroscopic method for quantification of polyethylene glycol (PEG) in waterlogged archaeological wood

Holzforschung ◽  
2020 ◽  
Vol 74 (11) ◽  
pp. 1043-1051
Author(s):  
Åke Henrik-Klemens ◽  
Katarina Abrahamsson ◽  
Charlotte Björdal ◽  
Alexandra Walsh
Keyword(s):  
Polyethylene Glycol ◽  
Spectroscopic Method ◽  
Calibration Model ◽  
Efficient Treatment ◽  
Raman Spectroscopic ◽  
Archaeological Wood ◽  
Validation Set ◽  
Impregnation Period ◽  
Polymer Impregnation

AbstractThe weakened microstructure of archaeological wood (AW) objects from waterlogged environments necessitates consolidation to avoid anisotropic shrinkage upon drying. Polymer impregnation through submergence or spraying treatments is commonly applied, and for larger and thicker objects, the impregnation period can stretch over decades. Thus, for efficient treatment, continuous monitoring of the impregnation status is required. Today, such monitoring is often destructive and expensive, requiring segments for extraction and chromatographic quantification. This study proposes an in situ Raman spectroscopic method for quantification of polyethylene glycol (PEG) in waterlogged AW. A calibration model was built on standards of PEG, cellulose powder, and milled wood lignin using orthogonal partial least squares (OPLS). The OPLS model had a strong linear relationship, and the PEG content in wood of varying degrees of degradation could be determined. However, the accuracy of the model was low with a root mean square error of prediction of 11 wt%. The low accuracy was traced to the heterogeneity in the calibration and validation set samples with regard to the small probing volume of the confocal instrumental setup.

In situ Raman Spectroscopic Observation of Polymer Chains in Semi-Crystalline Polyethylene Solids

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Yusuke Hiejima ◽  
Takumitsu Kida ◽  
Koh-hei Nitta
Keyword(s):  
Conformational Changes ◽  
Tensile Elongation ◽  
Spectroscopic Observation ◽  
Polymer Chains ◽  
Trans Conformation ◽  
Raman Spectroscopic ◽  
Higher Temperature ◽  
Microscopic Origin ◽  
Crystalline Polyethylene

AbstractIn situ Raman spectroscopy is applied for polyethylene solid under various environments to elucidate the morphological and conformational changes. The trans conformation retains up to higher temperature for high-density polyethylene, reflecting higher stability of the orthorhombic crystals composed of stacked trans chains. It is suggested that the conversion of the non-crystalline trans chains to the crystalline phase is the microscopic origin of thermal history in the crystallinity, whereas the transformation between the trans and gauche conformers is practically in thermal equilibrium. Microscopic and dynamic mechanism of deformation during uniaxial stretching is investigated for the molecular orientation and the microscopic load sharing on the crystalline and amorphous chains. Lower crystallinity results in smoother and higher orientation toward the stretching direction, as well as higher load on the amorphous chains, during tensile elongation.

scholarly journals Reversible Phase Transformations during In-Situ Heating of Uncapped Ge2Sb2Te5 Films

2021 ◽  
Vol 27 (S1) ◽  
pp. 2412-2414
Author(s):  
Chanchal Ghosh ◽  
Manish Singh ◽  
Paul Kotula ◽  
Helena Silva ◽  
C. Barry Carter
Keyword(s):  
Phase Transformations ◽  
In Situ Heating ◽  
Reversible Phase

Mapping gold nanoparticles on and in edible leaves in situ using surface enhanced Raman spectroscopy

RSC Advances ◽  
2016 ◽  
Vol 6 (65) ◽  
pp. 60152-60159 ◽  
Author(s):  
Zhiyun Zhang ◽  
Huiyuan Guo ◽  
Yingqing Deng ◽  
Baoshan Xing ◽  
Lili He
Keyword(s):  
Gold Nanoparticles ◽  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Mapping Technique ◽  
Raman Spectroscopic ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Spinach Leaves

A surface enhanced Raman spectroscopic (SERS) mapping technique was applied to qualitatively detect and characterize gold nanoparticles on and in spinach leaves in situ.

scholarly journals Fusion of MALDI Spectrometric Imaging and Raman Spectroscopic Data for the Analysis of Biological Samples

2018 ◽  
Vol 6 ◽  
Author(s):  
Oleg Ryabchykov ◽  
Juergen Popp ◽  
Thomas Bocklitz
Keyword(s):  
Biological Samples ◽  
Spectroscopic Data ◽  
Raman Spectroscopic
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