Compression effect on sustained-release and water absorption properties of cellulose tablets studied by heterospectral two-dimensional (2D) correlation analysis

2012 ◽  
Vol 4 (6) ◽  
pp. 1530-1537 ◽  
Author(s):  
Hideyuki Shinzawa ◽  
Kimie Awa ◽  
Yukihiro Ozaki
RSC Advances ◽  
2016 ◽  
Vol 6 (6) ◽  
pp. 4397-4409 ◽  
Author(s):  
Jing Zhao ◽  
Jihai Zhang ◽  
Tao Zhou ◽  
Xifei Liu ◽  
Qiang Yuan ◽  
...  

FTIR spectroscopy in combination with scaling-MW2D and 2D correlation analysis is used to study the reaction pathways of polyacrylonitrile copolymer fibers pre-oxidation.


2014 ◽  
Vol 1069 ◽  
pp. 176-182 ◽  
Author(s):  
Hideyuki Shinzawa ◽  
Kosuke Hashimoto ◽  
Hidetoshi Sato ◽  
Wataru Kanematsu ◽  
Isao Noda

ACS Catalysis ◽  
2015 ◽  
Vol 5 (6) ◽  
pp. 3588-3599 ◽  
Author(s):  
Qisong Xu ◽  
LiangFeng Guo ◽  
Tung Nguyen Dinh ◽  
Angie Cheong ◽  
Marc Garland

2002 ◽  
Vol 56 (12) ◽  
pp. 1562-1567 ◽  
Author(s):  
Young Mee Jung ◽  
Hyeon Suk Shin ◽  
Seung Bin Kim ◽  
Isao Noda

The direct combination of chemometrics and two-dimensional (2D) correlation spectroscopy is considered. The use of a reconstructed data matrix based on the significant scores and loading vectors obtained from the principal component analysis (PCA) of raw spectral data is proposed as a method to improve the data quality for 2D correlation analysis. The synthetic noisy spectra were analyzed to explore the novel possibility of the use of PCA-reconstructed spectra, which are highly noise suppressed. 2D correlation analysis of this reconstructed data matrix, instead of the raw data matrix, can significantly reduce the contribution of the noise component to the resulting 2D correlation spectra.


2016 ◽  
Vol 18 (27) ◽  
pp. 17973-17982 ◽  
Author(s):  
R. Geitner ◽  
J. Kötteritzsch ◽  
M. Siegmann ◽  
R. Fritzsch ◽  
T. W. Bocklitz ◽  
...  

C60-fullerene–anthracene self-healing copolymers were studied by time-, temperature- and concentration-dependent FT-Raman spectroscopy and advanced 2D correlation analysis.


2005 ◽  
Vol 59 (8) ◽  
pp. 1060-1067 ◽  
Author(s):  
Peter Haider ◽  
Gary L. Haller ◽  
Lisa Pfefferle ◽  
Dragos Ciuparu

Surface characterization and catalysis can significantly benefit from the application of generalized two-dimensional (2D) correlation analysis. This two-dimensional approach allows a better resolution of overlapping peaks, can reveal new features not readily observable in the raw spectra, gives clear evidence for spectral intensities that change as an effect of a perturbation applied to the system, and allows the establishment of time sequences for the changes occurring in different spectral features of interest for determining reaction intermediates and/or mechanisms. The interpretation of the synchronous and asynchronous plots was observed to lead to erroneous time sequences when spectral features change in a nonmonotonic way, such as a biphasic or oscillatory behavior, under the influence of a perturbation. We propose a new approach to the 2D correlation analysis to avoid misinterpretation of the results calculated in the asynchronous plot. Progressive correlation analysis (ProCorA) calculates the synchronous plot from the first two spectra of the data matrix and one spectrum is added at every step of the analysis. The sequence of changes can be set up from the progressive evolution of peaks in both the synchronous and asynchronous plots.


2005 ◽  
Vol 19 (01n03) ◽  
pp. 281-284 ◽  
Author(s):  
IN-SANG YANG ◽  
YOUNG MEE JUNG ◽  
SEUNG BIN KIM ◽  
M. V. KLEIN

Two-dimensional (2D) correlation analysis is applied to the temperature dependence on the Raman spectra of superconducting YNi 2 B 2 C single crystal. 2D correlation analysis on the temperature dependence of the B 1g superconducting gap peak shows strong correlation with the Ni B 1g phonon peak near 200 cm -1. The analysis on the B 1g phonon peak itself shows that the peak is composed of essentially two peaks at 197 and 203 cm -1, and only the weight of the two peaks changes as the temperature changes. The result suggests that there are two distinctive environments of the Ni - B bonds in YNi 2 B 2 C system at the superconducting state.


2003 ◽  
Vol 57 (2) ◽  
pp. 164-167 ◽  
Author(s):  
Z. W. Yu ◽  
I. Noda

Data pretreatment is of importance in two-dimensional (2D) correlation analysis when composition is used as a perturbation parameter. For composition-oriented studies, different normalization methods based on both external parameters (i.e., concentration) and internal parameters (i.e., absorbance from individual components) have been compared. It was found that when there is no overlapping between absorption bands of interest, no normalization is needed for data pretreatment. When overlapped bands must be used for 2D correlation analysis, the mean-centered normalization method could be used to obtain correct signs in synchronous spectra for a transformation process in the specific form of A → kC. The intensity of the 2D spectrum, however, may not accurately reflect quantitative information of the overall extent of spectral intensity variation observed during experiments.


2003 ◽  
Vol 57 (8) ◽  
pp. 984-990 ◽  
Author(s):  
Hyun Chul Choi ◽  
Young Mee Jung ◽  
Seung Bin Kim

We applied soft X-ray absorption spectroscopy (XAS) and two-dimensional (2D) correlation analysis to the first lithium insertion–extraction cycle in a Li1+xV3O8/Li cell in order to investigate the electrochemical reactions of lithium with the Li1+xV3O8 electrode. The V LII,III-edge and O K-edge spectra of the Li1+xV3O8 electrode were obtained for varying electrode lithium content. The insertion of lithium leads to the reduction of the V5+ species present in the pristine Li1+xV3O8 electrode, and to the red shift and the broadening of the spectral features of the V LII,III edge compared to those of the pristine electrode. In the extraction process, the main spectral features at the highest value of the extraction of lithium show some differences compared to the features of the pristine electrode spectrum due to the residual lithium ions in the Li1+xV3O8 structure. The O K-edge spectra revealed that the insertion of lithium mainly affects the V 4sp–O 2p bonds and consequently induces a change in bonding geometry. The 2D correlation analysis of these spectra clearly shows that V–O bonds are significantly perturbed by the insertion–extraction of lithium into the Li1+xV3O8 electrode.


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