scholarly journals Pyrolysis kinetics and thermal decomposition behavior of polycarbonate - a TGA-FTIR study

2014 ◽  
Vol 18 (3) ◽  
pp. 833-842 ◽  
Author(s):  
Esin Apaydin-Varol ◽  
Sevgi Polat ◽  
Ayse Putun
Keyword(s):  
Activation Energy ◽  
Fourier Transform ◽  
Reaction Order ◽  
Fourier Transform Infrared ◽  
Pyrolysis Kinetics ◽  
Heating Rates ◽  
Exponential Factor ◽  
Thermogravimetric Analyzer ◽  
Fourier Transform Infrared Spectrometer ◽  
Infrared Spectrometer

This study covers the thermal degradation of polycarbonate by means of Thermogravimetric Analyzer coupled with Fourier transform infrared spectrometer (TGA-FTIR). Thermogravimetric analysis of polycarbonate was carried out at four different heating rates of 5, 10, 15, and 20?C per minute from 25?C to 1000?C under nitrogen atmosphere. The results indicated that polycarbonate was decomposed in the temperature range of 425-600?C. The kinetic parameters, such as activation energy, pre-exponential factor and reaction order were determined using five different kinetic models; namely Coast-Redfern, Friedman, Kissinger, Flynn-Wall-Ozawa (FWO), and Kissinger-Akahira-Sunose (KAS). Overall decomposition reaction order was determined by Coats-Redfern method as 1.5. Average activation energy was calculated as 150.42, 230.76, 216.97, and 218.56 kJ/mol by using Kissinger, Friedman, FWO, and KAS models, respectively. Furthermore, the main gases released during the pyrolysis of polycarbonate were determined as CO2, CH4, CO, H2O, and other lower molecular weight hydrocarbons such as aldehydes, ketones and carbonyls by using thermogravimetric analyzer coupled with Fourier transform infrared spectrometer.

Kinetic Study on Pyrolysis of Gentamicin Residue

2014 ◽  
Vol 955-959 ◽  
pp. 2803-2808
Author(s):  
Ren Ping Liu ◽  
Rui Yao ◽  
Hui Li
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
Thermochemical Conversion ◽  
Pyrolysis Kinetics ◽  
Heating Rates ◽  
Exponential Factor ◽  
Thermogravimetric Analyzer ◽  
Basic Work ◽  
Mechanism Function ◽  
Kinetics Of

Gentamicin bacteria residue contains high organic compound. The technology of thermochemical conversion can effectively solve the problem of bulk gentamicin residue disposal, research on pyrolysis kinetics of the reaction is the basic work for thermochemical conversion . In this paper, Pyrolysis experiments were carried out in a thermogravimetric analyzer under inert conditions and operated at different heating rates (5, 10, 20 K/min).Two different kinetic models, the iso-conversional Ozawa–Flynn–Wall (Ozawa) models and Satava method were applied on TGA data of gentamicin residue to calculate the kinetic parameters including activation energy, pre-exponential factor and Mechanism function. The results showed that: gentamicin bacteria residue lost most weight of it between 100-650 °C , about 74.23% of the whole sample can decompose under high temperature. The pyrolysis function for gentamicin residue should be G(α) =[-ln(1-α)]3.

Broadband terahertz dielectric measurement based on multi-beam interference and Fourier transform infrared spectrometer

2018 ◽  
Vol 32 (25) ◽  
pp. 1850298
Author(s):  
Jie Shi ◽  
Mao-Rong Wang ◽  
Kai Zhong ◽  
Chu Liu ◽  
Jia-Lin Mei ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Room Temperature ◽  
Fourier Transform Infrared ◽  
Refraction Index ◽  
Good Alternative ◽  
Dielectric Measurement ◽  
Terahertz Time Domain Spectroscopy ◽  
Fourier Transform Infrared Spectrometer ◽  
Limited Frequency ◽  
Infrared Spectrometer

We demonstrate a method for obtaining optical coefficients over a broad terahertz spectral range from 1.5 THz to 16 THz at room temperature. Based on the interferograms directly acquired by a Fourier transform infrared spectrometer (FTIR), multi-beam interference principle combining Fresnel’s formula is employed to extract the refraction index and the extinction coefficient, giving the basis for calculating dielectric coefficients. It avoids the uncertainty and phase instability while using Kramers–Kronig (KK) relations and overcomes the limited frequency range of terahertz time-domain spectroscopy (TDS). Moreover, this method has better stability and is needless of cutting useful information between neighboring interference peaks for thin samples compared with TDS, making it a general processing method for interferograms and a good alternative for terahertz dielectric measurement.

scholarly journals Intensity Simulation of a Fourier Transform Infrared Spectrometer

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1833 ◽  
Author(s):  
Zhuoya Ni ◽  
Qifeng Lu ◽  
Yishu Xu ◽  
Hongyuan Huo
Keyword(s):  
Fourier Transform ◽  
Brightness Temperature ◽  
Michelson Interferometer ◽  
Fourier Transform Infrared ◽  
Core Element ◽  
Simulation Process ◽  
Fourier Transform Infrared Spectrometer ◽  
Infrared Spectrometer ◽  
Input Spectrum ◽  
The Fourier Transform

This paper introduces an intensity simulation for the Fourier transform infrared spectrometer whose core element is the Michelson interferometer to provide support for the on-orbit monitoring of the instrument and to improve the data processing and application of the Fourier transform spectrometer. The Geostationary Interferometric Infrared Imager (GIIRS) aboard on Fengyun-4B (FY-4B) satellite, which will be launched in 2020, aims to provide hyperspectral infrared observations. An intensity simulation of the Michelson interferometer based on the GIIRS’s instrument parameters is systematically analyzed in this paper. Off-axis effects and non-linearity response are two important factors to be considered in this simulation. Off-axis effects mainly cause the wavenumber shift to induce a large brightness temperature error compared with the input spectrum, and the non-linearity response reduces the energy received by the detector. Then, off-axis effects and a non-linearity response are added to the input spectrum successively to obtain the final spectrum. Off-axis correction and non-linearity correction are also developed to give a full simulation process. Comparing the corrected spectrum with the input spectrum, we can see that the brightness temperature errors have a magnitude of 10−3 K, and this fully proves the reliability and rationality of the whole simulation process.

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