Fourier transform infrared spectra of the

Figure 11.4 Fourier transform infrared spectra of the waxes derived from the pyrolysis of high-density polyethylene, low-density polyethylene and polypropylene...

Fig. 8. (A) X-ray diffraction spectra (unit, nm) and (B) polarized Fourier transform-infrared spectra of the four polymorphs in ricinoleic acid (SRS).

Infrared spectroscopy is used to identify and quantitatively analyse chemical compounds, mixtures, extent of reaction, and molecular stmcture. Various chemical compounds absorb infrared radiation at frequencies corresponding to their own molecular vibrational frequencies. Fourier transform infrared spectra of the textile surfaces is carried out to determine the functional groups and the extent of the reaction of the bioactive groups with the textile. 

Fourier transform infrared spectra of the chitosan films and the chitosan/clay films were collected using a Spectrum 400 Perkin Elmer operating in the range of 400-4000 cm i at a resolution of 4 cm. ... 

Bas Baskakov, O.I., Civis, S., Kawaguchi, K. High resolution emission Fourier transform infrared spectra of the 4p-5s and 5p-6s bands ofArH, J. Chem. Phys. 122, 114314 (2005) 1-11. 

Fourier-transformed infrared spectra of the photodegradated PPV film show a drastic increase in carbonyl groups due to the oxygen in air. Carbonyl moieties act as defects at which nonradiative decay occurs, so that there is a dramatic reduction of PL intensity [209,211]. A photooxidation study of PPV and its derivatives shows that the oxidation results in chain scission by breaking the vinylene group [209,210]. In addition to oxygen, other environmental factors cause degradation of the device, such as moisture and particles in air. In order to avoid them, device fabrication should be carried out under clean-room conditions. 

Fig. 4 Fourier transform infrared spectra of the silver nanoparticles produced using the cell extract of P. plecoglossicida. Significant vibration bands are labeled...

Figure 10.6. In situ Fourier transform infrared spectra of decane SCR-NO in the presence and absence of hydrogen on Ag/Al203 at 200°C. Evolution of intensities of the bands characteristic for adsorbed species (monodentate nitrates 1245 cm-1, bidentate nitrates 1295 cm-1, —CN 2150 cm-1 and —NCO 2230 cm-1. 1000 ppm NO, 6vol.%02,750 ppm decane, Oor 1000 ppm H2 (reproduced with permission from Ref. [12]).

The effect of parameters, such as temperature and fluid composition on extraction yield and selectivity are reported. Fourier transform infrared spectra of cork, extraction residues and extracts are also presented. 

This method gained a significant improvement with the introduction of the contemporary infrared technique with a Fourier transformer (FT-IR), permitting to obtain measurable values of adsorption of the infrared light even from single black foam films. The thickness of the aqueous core is derived from the adsorption at 3400 cm 1 which is related to the OH stretching vibration of the water molecules. Umemura et al. [114] have employed the polarised Fourier transformed infrared spectra for the study of the water content of NaDoS black films. The cell used to form films of ca. 2 cm2 area is illustrated in Fig. 2.19. By fitting the calculated curved of polarised FT-IR spectra to the respective experimentally obtained... 

A spectrometric application was performed by Lopez-Sanchez et al. (48), who applied hierarchical clustering with the Ward algorithm on attenuated total reflection Fourier transform infrared spectra of toothpastes in order to establish different groups in the sample population. 

Another example, but for spectroscopic data, is found in Gaetano et al. (54), who applied SVM on the Fourier-transform infrared spectra of olive oils in order to classify them according to geographical region. SVM performed... 

OPTICAL, PHYSICAL, THERMAL AND CHEMICAL PROPERTIES OF THE MOST FREQUENTLY COLLECTED PLASTICS FOURIER TRANSFORM INFRARED SPECTRA OF POLYMERS FREQUENTLY FOUND IN COLLECTIONS TERMS USED TO DESCRIBE THE DEGRADATION OF PLASTICS... 

Fourier transform infrared spectra of Csl pellets of the AI13- and GaAli2-sulfate and selenate salts and of the deuterated Al -sulfate salt were run on a Mattson Galaxy 4030 spectrometer at a resolution of 2 wavenumbers. 

Figure 3. Visible and Fourier transform infrared spectra of polySBCMU in various mixtures of CHCI3 and hexane The mole fraction of CHCI3 in hexane is indicated Polymer concentrations are 1 9 x 10" mol/lit for the visible spectra and 1 3 x 10"3 for the infrared spectra (From reference 1)...

Figure 2 Infrared spectra of polystyrene with (curve a) a mixture of crystalline and amorphous forms, (curve b) a mixture of crystalline forms only, (curve c) one pure crystalline form obtained by spectral subtraction, (curve d) another pure crystalline form obtained by spectral subtraction and (curve e) subtraction result of curves b - c - d. Reproduced with permission of John Wiley Sons Limited from Musto P, Tavone S, Guerra G and DeRosa C (1997) Evaluation by Fourier transform infrared spectroscopy of the different forms of syndiotactic polystyrene samples. Journal of Polymer Science B 35 1055-1066.

We have obtained the near-infrared Fourier transform Raman spectra of the primary donor of Rc. gelatinosus in its reduced and oxidized states and have compared them with those of Rb. sphaeroides. Using 1064 nm excitation, i) the reresonance Raman spectrum of the primary donor in its reduced state (P) via its 865 nm absorption band, and ii) the resonance Raman spectrum of P in its cation, radical state (P -) via its 1245 nm absorption band, are selectively observed. The details of these resonance enhancements and the selective observation of the primary donor in these two redox states are described for the specific case of Rb. sphaeroides elsewhere... 

Principal component analysis has been used in combination with spectroscopy in other types of multicomponent analyses. For example, compatible and incompatible blends of polyphenzlene oxides and polystyrene were distinguished using Fourier-transform-infrared spectra (59). Raman spectra of sulfuric acid/water mixtures were used in conjunction with principal component analysis to identify different ions, compositions, and hydrates (60). The identity and number of species present in binary and tertiary mixtures of polycycHc aromatic hydrocarbons were deterrnined using fluorescence spectra (61). 

The infrared spectra of the different samples were taken with a Fourier Transform infrared spectrometer (Digilab FTS-14) using the double beam mode vs. air as reference. 150 scans per sample and 100 scans per reference, at a resolution of 4 cm-l, were taken for every sample. All spectra were stored on tape, and a digital substraction of the after- and- before UV exposure (or any other sample treatment) spectra was performed, whenever needed, by an on-line computer, thus permitting a better visualization of the spectral changes in the polymer by UV- photooxidation. 

Non-ionic surfactants of a commercial washing powder were separated by supercritical fluid chromatography (SFC) and determined by APCI-MS. The constituents were first extracted by supercritical fluid extraction (SFE) using C02 with or without methanol as a modifier. Variations of the conditions resulted in a selective extraction of the analytes, which could be determined without further purification. Six groups of surfactants were observed, four of which are alkyl-polyethoxylates. The presence of APEO could be excluded by identification recording SFC-FTIR (Fourier transform infrared) spectra [31]. 

Structural study of polysaccharides and other carbohydrates in solution or in the amorphous state has been significantly enhanced through the application of Fourier-transform, infrared spectroscopy. Among the advantages of this method may be mentioned the high quality of the spectra, and the in-house ability to interact with the computer, so that the digitized spectra may be stored and manipulated in such a way that additional information is obtained. The application of F.t.-i.r. spectroscopy in the field of carbohydrate chemistry and biochemistry is still in its infancy,182 but... 

The arrival of Fourier-transform infrared spectrometers in the early 1970s afforded much better spectra in the <5CH3/(5CH2/vC=C region, partly because of... 

Autoscaling can also be used when all of the variables have the same units and come from the same instrument. However, it can be detrimental if the total variance information is relevant to the problem being solved. For example, if one wants to do an exploratory chemometric analysis of a series of FTIR (Fourier transform infrared) spectra in order to determine the relative sensitivities of different wavenumbers (X-variables) to a property of interest, then it would be wise to avoid autoscaling and retain the total variance information because this information is relevant for assessing the sensitivities of different X-variables. 

Infrared spectroscopy has been widely applied when studying the silica surface.1 Figure 3.3 shows typical FTIR (Fourier Transform Infrared) spectra with photoacoustic detection (cfr. appendix A) of Kieselgel 60, treated for 17 h at (a) 373 K (b) 673 K and (c) 973 K. The Y-scales of the three spectra are not comparable. 

The most basic information that is needed for constructing a global potential energy surface for gas phase MD simulations is the structures and vibrational frequencies. The earliest information about gas-phase RDX molecular structures was obtained from theoretical calculations [54-58]. In 1984 Karpowicz and Brill [59] reported Fourier transform infrared spectra for vapor-phase (and for the a - and p -phase) RDX in 1984, however, their data precluded a complete description of the molecular conformations and vibrational spectroscopy. More recently, Shishkov et al. [60] presented a more complete description based on electron-scattering data and molecular modeling. They concluded that the data were best reproduced by RDX in the chair conformation with all the nitro groups in axial positions. 

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