scholarly journals Facile and fast determination of Si/Al ratio of zeolites using FTIR spectroscopy technique

2021 ◽  
Vol 311 ◽  
pp. 110683
Author(s):  
Yik-Ken Ma ◽  
Severinne Rigolet ◽  
Laure Michelin ◽  
Jean-Louis Paillaud ◽  
Svetlana Mintova ◽  
...  
2021 ◽  
Vol 2086 (1) ◽  
pp. 012140
Author(s):  
D D Firsov ◽  
M Yu Chernov ◽  
V A Solov’ev ◽  
O S Komkov

Abstract Infrared photoreflectance (PR) spectra of In(Ga,Al)As/GaAs metamorphic heterostructures have been obtained using a novel photomodulation FTIR spectroscopy technique. An analysis of the PR spectra features allowed us to estimate the critical point energies corresponding to the direct interband transitions in various regions of the In(Ga,Al)As heterostructures, and distinguish the PR signals originating from Fabry-Perot interference. Observation of Franz-Keldysh oscillations originating from the InAlAs virtual substrate and an InGaAs waveguide layer has enabled determination of the built-in electric field intensities within the heterostructures. The obtained results open up possibilities for contactless control of free carrier concentration in In(Ga,Al)As/GaAs metamorphic heterostructures developed for growth of emitters of mid-IR spectral range.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Sinem Tunçer ◽  
Rafig Gurbanov

AbstractObjectivesThe expression level of Vascular Endothelial Growth Factor (VEGF) is assumed as a prognostic marker for several tumor types, including colorectal cancer. Therefore, the determination of pre- and post-therapy levels of VEGF appears to have great value in the assessment of tumor prognosis. Enzyme-Linked Immunosorbent Assay (ELISA) is commonly used for the determination of serum or plasma VEGF levels, but the method is costly and time-consuming. In this study, we aimed to describe a rapid and cost-effective analysis method to discriminate VEGF overexpressing colorectal cancer-derived conditioned medium (CM).MethodsAttenuated Total Reflection (ATR)-Fourier Transform Infrared (FTIR) spectroscopy, combined with Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA), was used to differentiate VEGF overexpressing colorectal cancer cell line CM from CM obtained from the corresponding control cells which express and secrete relatively lower amount of VEGF.ResultsSamples belong to VEGF overexpressing colorectal cancer cells were clearly distinguished from the control group with very high PC scores as PC1 + PC2 = 96%. Besides, a 100% accurate distinction between these two groups was achieved by the LDA analysis.ConclusionsATR-FTIR spectroscopy combined with pattern recognition techniques was able to discriminate CM of VEGF overexpressing colorectal cancer cells with high efficiency and accuracy.


2004 ◽  
Vol 18 (4) ◽  
pp. 665-668 ◽  
Author(s):  
M.M.H Huisman ◽  
A Oosterveld ◽  
H.A Schols

Biochemistry ◽  
2012 ◽  
Vol 51 (26) ◽  
pp. 5339-5347 ◽  
Author(s):  
Damien Farrell ◽  
Helen Webb ◽  
Michael A. Johnston ◽  
Thomas A. Poulsen ◽  
Fergal O’Meara ◽  
...  

2016 ◽  
Vol 8 (37) ◽  
pp. 6705-6710 ◽  
Author(s):  
Pengcheng Han ◽  
Daming Dong ◽  
Xiaofan Du ◽  
Leizi Jiao ◽  
Xiande Zhao

Laser-induced breakdown spectroscopy was used for the fast determination of calcium concentration in the internal tissues of a single seed. Compared with conventional methods, LIBS had obvious advantages, such as a little analysis spot, little ablation, high precision, and small influence on the seed vigor.


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