Concerning the Application of FT-IR to the Study of Coal: A Critical Assessment of Band Assignments and the Application of Spectral Analysis Programs

1981 ◽  
Vol 35 (5) ◽  
pp. 475-485 ◽  
Author(s):  
Paul C. Painter ◽  
Randy W. Snyder ◽  
Michael Starsinic ◽  
Michael M. Coleman ◽  
Deborah W. Kuehn ◽  
...  

The problems associated with the application of FT-IR to the characterization of coal structure are critically discussed. The controversies concerning band assignments are considered and it is concluded that the strong 1600 cm−1 band can be assigned to an aromatic ring stretching mode that in most coals is intensity enhanced by the presence of phenolic groups. The application of computer routines to the determination of OH and CH groups is considered. Established criteria for curve fitting are applied to the problem. Qualitative identification of functional groups is achieved, but consistent quantitative measurements will require a determination of the relationship between the extinction coefficients of resolved bands.

2011 ◽  
Vol 239-242 ◽  
pp. 1382-1385
Author(s):  
Na Xu ◽  
Xiao Dong Shen ◽  
Sheng Cui

The electrochromic PANI film was prepared by emulsion polymerization with dodecyl benzene sulphonic acid (DBSA) as dopant and ammonium persulfate (APS) as initiator. Ultrasonic dispersion was adopted in the polymerization. The electrochemical properties, the surface morphology and structure of the prepared PANI film was characterized by means of Fourier Transform infrared spectroscopy (FT-IR), cyclic voltammograms (CV) and field emission scanning electron microscope (FE-SEM), respectively. The relationship between the morphology and properties of PANI film was detailedly discussed. The PANI film exhibited an excellent electrochromism with reversible color changes form yellow to purple. The PANI film also had quite good reaction kinetics with fast switching speed, and the response time for oxidation and reduction were 65 ms and 66 ms, respectively.


Irriga ◽  
2001 ◽  
Vol 6 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Marcio Antonio Vilas Boas ◽  
Eurides Kuster Macedo Júnior ◽  
Silvio Cesar Sampaio ◽  
Melânia Inês Valiati

CARACTERIZAÇÃO HIDRÁULICA DO MICROASPERSOR DAN SPRINKLERS GRUPO MODULAR                                     Márcio Antônio Vilas BoasEurides Kuster Macedo JuniorSilvio César SampaioMelânia Inês ValiatiUNIOESTE - Universidade Estadual do Oeste do ParanáCEP: 85814-110 - Cascavel – PR - Brasil - Cx. Postal   711Fone: (045) 225 -2100  (R-249) - Fax : (045) [email protected]  1 RESUMO  Este  trabalho  teve  como  objetivo  avaliar as características hidráulicas  do  microaspersor DAN SPRINKLERS do grupo modular de fabricação da DAN SPRINKLERS - ISRAEL, de uso recente no Oeste do Paraná. Os ensaios foram realizados no Laboratório de Hidráulica do Departamento de Engenharia da Universidade Estadual do Oeste do Paraná – UNIOESTE. Na  avaliação dos microaspersores  estudou-se, a variação decorrente do processo de fabricação e a determinação da equação característica da relação vazão–pressão. Os microaspersores do Grupo modular com diâmetros de bocais 0,94; 1,16;1,41;1,92 e 2,34 mm,  foram submetidos às pressões de 100, 150, 200, 250, 300 e 350 kPa. As equações características determinadas indicaram que o microaspersor testado não é auto-compensante , tolerante a sensibilidade de variações de pressões e que a equação potencial se ajusta bem aos dados. Os coeficientes de variação de fabricação obtidos foram menores que 5%, classificando-se, de acordo com a Norma ISO, como de categoria A. UNITERMOS: Microaspersão, coeficiente de variação, modelo potencial.  VILAS BÔAS, M. A., MACEDO JUNIOR, E. K. HYDRAULIC CHARACTERIZATION OF MICROSPRINKLER DAN SPRINKLER - MODULATE GROUP   2 ABSTRACT This work had as objective to evaluate the characteristics hydraulic of the microsprinklers of the group to modulate of production of DAN SPRINKLERS - ISRAEL, of recent use in the West of Paraná. The tests was accomplished in the Laboratory of Hydraulics of the Department of Engineering of the State University of the West of Paraná - UNIOESTE. In the evaluation of the microasprinklers it was studied such characteristics as, the variation due to the production process and the determination of the characteristic equation of the relationship vazão-pressure. The microsprinklers of the Group to modulate with diameters of nozzle 0,94; 1,16;1,41;1,92 and 2,34 mm, the pressures were submitted 100, 150, 200, 250, 300 and 350 kPa. The certain characteristic equations showed that the tested microsprinklers is not solemnity-compensante and that the potential equation was fit well to the data. The obtained coefficients of production variation were everybody below 5% being able to not this way to classify them in agreement with for ISO  category as A. KEYWORDS: Microsprinkler, coefficient variation, power function.


2018 ◽  
Vol 10 (1) ◽  
pp. 21
Author(s):  
Iyan Sopyan ◽  
Intan Mutiara Sari ◽  
Insan Sunan K.

Objective: Interactions of active pharmaceutical ingredients (API) as well as pharmaceutical excipients don’t occur in a pharmaceutical dosage form. Base on structures of paracetamol (PCT) and chlorphenamine maleate (CTM), its combination is possible to give a physical interaction in the solid state. This study was conducted to investigate the physical interaction of PCT and CTM in the solid state.Methods: Characterization used the polarization microscope, solubility test, powder x-ray diffraction (PXRD) to observe peak shifting in 2Ɵ angle, and fourier transform infrared spectroscopy (FT-IR) to examine wavenumber shifting.Results: Results of solubility exhibited an increased solubility percentage with increasing concentration. Polarization microscope analysis presented a combination of crystal morphology after the two substances were mixed in an equimolar ratio. The result of melting point determination of each pure substance was 172 °C for PCT, 132 °C for CTM, and 170 °C for the mixture of the two substances in various ratios. Diffractogram showed the shifting at angle 2Ɵ: 20.715, 19.355-23.500 and 21.840, 26.455-20.330 for concentration ratio of PCT: CTM in (132:0.5) and (330:1) respectively and any change in the functional group was observed from infrared spectrum.Conclusion: All evaluation of PCT and CTM in the solid state has exhibited the interaction in solid condition.


2010 ◽  
Vol 69 ◽  
pp. 123-128 ◽  
Author(s):  
Salvatore Andini ◽  
Raffaele Cioffi ◽  
Francesco Colangelo ◽  
Claudio Ferone ◽  
Fabio Montagnaro ◽  
...  

In this work three samples of MSWI ash have been stabilized in systems containing coal fly ash and able to give geopolymers through a polycondensation reaction. Monolithic products were obtained with both MSWI ashes as received and after chloride partial removal by water washing. The polycondensation products have been characterized qualitatively by means of FT-IR spectroscopy and scanning electron microscopy (SEM) and quantitatively through the determination of the amount of reacted water and silicate. Differently from traditional cement based stabilization systems, those based on geopolymerization show a chemical behaviour almost insensitive to the presence of chlorides and sulphates in the MSWI ash. On the other hand, the microstructure is strongly affected by the content of soluble salts.


1989 ◽  
Vol 170 ◽  
Author(s):  
Juan C. Figueroa ◽  
Linda S. Schadler ◽  
Campbell Laird

AbstractThe effect of fiber surface treatments on the relationship between the tensile strength of a filament and the shear strength of its interphase is one of the central issues facing composite materials technologists today. We demonstrate here that analysis of fragmentation phenomena in monofilament composites can simultaneously yield information about these two parameters. Characterization of shear stress transfer zones in non-critical fragments has led us to the determination of interphase strength.A phenomenological treatment that highlights the role of the matrix in the fragmentation process is presented here. This analysis considers issues such as the strain energy exchange between a failing fiber and the matrix, as well as interphase relaxation due to the viscoelastic nature of the matrix. Our observations of the fragmentation phenomena in AU4/polycarbonate monofilament composites indicate that the fiber/matrix interaction in this system is governed by micromechanical locking.


2012 ◽  
Vol 554-556 ◽  
pp. 1216-1222
Author(s):  
Hai Xin Shi ◽  
Yan Zhen Yin ◽  
Xiao Xi Hu ◽  
Shu Fei Jiao

The canna amylose (CAM) was separated from canna starch grown in China and purified both using the method of n-butanol recrystallization. The purity, morphology, spectral properties and molecular weight of CAM were characterized by ultraviolet and visible spectrophotometer (UV/Vis), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscope (FT-IR) and Ubbelohde viscometer. Maximum absorption wavelength of the purified CAM (635-638 nm) and it’s blue values (BV) (1.167 ± 0.209) prove that the purification of the CAM by n-butanol recrystallization was successfully carried out. The SEM results show that CAM granule surface become rougher and the CAM granule size become smaller than that of canna starch. The XRD results suggest that most of CAM granule is amorphous. And the FT-IR results show that the basic chemical groups of canna starch are also presented in CAM. However, the amorphous area of CAM is increased. The intrinsic viscosity and viscosity-average molecular weight of CAM is 78.5 mL/g and 1.65×105, respectively.


2009 ◽  
Vol 63 (9) ◽  
pp. 1041-1049 ◽  
Author(s):  
Johannes Kiefer ◽  
Katharina Obert ◽  
Jürgen Fries ◽  
Andreas Bösmann ◽  
Peter Wasserscheid ◽  
...  

The conversion of biogenic carbohydrate feedstock to chemicals or energy equivalents is a promising approach to solve the problem of limited fossil fuel reserves. Some concepts to accomplish these transformations are based on ionic liquids (ILs) due to their ability to dissolve biopolymers, such as cellulose, and even complex biopolymer mixtures, such as wood. However, concerning control of such conversions, a reliable tool for process analytics is required. In this paper we demonstrate the applicability of Fourier transform infrared (FT-IR) spectroscopy to perform quantitative concentration measurements of glucose and cellobiose as two examples of carbohydrates dissolved in the room-temperature ionic liquid [EMIM][OAc] (1-ethyl-3-methylimidazolium acetate). For this purpose, binary mixtures in the range 0–20 wt% have been studied. A previously developed method for the data analysis, which was based on the Beer–Lambert relation, has been universalized by employing empirical correlations between the measured quantity (i.e., extinction) and the carbohydrate concentration. In the entire spectral range under investigation (500–4000 cm−1) numerous individual wavenumbers have been identified, allowing quantitative measurements with high accuracy and precision.


2021 ◽  
Vol 25 (11) ◽  
pp. 138-142
Author(s):  
Anamica . ◽  
Poorn Prakash Pande

In this study, we report the synthesis and characterization of polymer hydrogels. The polymer gels have been prepared from acrylic acid (AA) monomer using allyl pentaerythritol as the crosslinker in the presence of potassium persulfate initiator. The synthesized polymer gels have been characterized by Fourier-transform infrared (FT-IR) spectroscopy. The swelling capacity and crosslink density of the synthesized polymer gels have been determined and it was found that some of the polymer samples behave like super-absorbent polymers. These polymeric-gels can be utilized in various applications viz. as a catalyst for dye removal, for anion removal from water and for heavy metal removal etc.


Langmuir ◽  
2011 ◽  
Vol 27 (13) ◽  
pp. 8486-8493 ◽  
Author(s):  
Jason K. Cooper ◽  
Alexandra M. Franco ◽  
Sheraz Gul ◽  
Carley Corrado ◽  
Jin Z. Zhang

2004 ◽  
Vol 126 (4) ◽  
pp. 574-579 ◽  
Author(s):  
Baozhong Yang ◽  
C. Steve Suh

Spectral analysis has been widely applied to the detection of bifurcation and the determination of the extent to which dynamic instability and chaotic responses develop. However, because spectral analysis employs stationary sinusoids in representing time-varying signals of inherent nonlinearity, the use of Fourier domain methodologies would inexorably risk misinterpreting the true characteristics and obscuring the underlying physics of the nonlinear system being investigated. The fact that the amplitude and frequency of all the individual spectral component of a nonlinear, nonstationary dynamic response are modulated and coupled in time necessarily implies that, if the inception and transition of a bifurcated state of unstable motion is to be fully characterized, amplitude modulation and frequency modulation need to be temporally decoupled. The fundamental notion of instantaneous frequency defines frequency as the temporal gradient of phase and thus provides a powerful mechanism through which amplitude modulation and frequency modulation can be disassociated. Results of applying instantaneous frequency to the characterization of bifurcation and evolution of instability for a cracked rotor also indicate that instantaneous frequency interprets nonlinear rotary responses with sound physical bases.


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