Reflectance Infrared Fourier Transform Spectra Research Articles

Automated geological logging from FTIR reflectance spectra utilising geochemical and historical logging constraints

In iron ore exploration, mineral samples are obtained from a drill hole and their compositions logged as proportions of material types, which encapsulate mineralogical and textural attributes. This logging is used to inform the properties, i.e. mineralogical, grade, and handling, of the orebody during mining and processing. Logging has historically been recorded manually, and as such is subjective and time consuming.We have developed a system that uses objective datasets, namely Fourier Transform Infrared reflectance spectra, geochemical assays, and a priori geological constraints, within a machine learning system to objectively log these mineral samples. The system is trained on samples logged by expert geologists in a laboratory environment. The resultant objective logging optimally satisfies constraints including matching the theoretical chemistry (calculated from the logging) to the laboratory assays, and satisfying the sample’s known geological context.We present comparisons of the logged material type proportions recorded by expert geologists in a laboratory environment with the proportions produced by the objective logging system, and also against geologists’ field logging proportions of the same samples. These comparisons demonstrated that the objective logging system’s proportions closely matched the geochemically validated expert-logged proportions for important individual material types, and over larger mineralogical groupings, and groups of material types of different textural hardness. Additionally, the system outperformed field logging, relative to laboratory-based logging, according to r2 and RMSE metrics. These results demonstrate an improvement over geologists’ field logging, while removing the subjectivity inherent in the human logging process.

Epitaxial silicon transition zone measurements by spreading resistance profiling and Fourier transform infrared reflectometry

AbstractSilicon epitaxy is an essential building block in the manufacturing of complementary metal‐oxide semiconductor (CMOS) devices. Accurate determination of epitaxial layer thickness is indispensable for a uniform and reproducible process. In this paper, we compare thickness values of the transition zone (TZ) in silicon epitaxial wafers obtained by two of Semilab's production‐compatible electrical and optical characterization techniques: Fourier‐transform infrared (FTIR) reflectometry and spreading resistance profiling (SRP). We demonstrate a high correlation between TZ thicknesses obtained from the optical modeling of FTIR reflectance spectra and SRP profiles. The dependence of TZ thickness change on the high‐temperature annealing steps is also examined. FTIR reflectometry thus offers a quick, contactless alternative for obtaining structural parameters of an epitaxial layer, and these values can be well matched to those given by SRP.

Locality determination of inky black omphacite jades from Myanmar and Guatemala by nondestructive analysis

AbstractLocality identification of high‐quality inky black omphacite jades (inky jades) from Myanmar and Guatemala is becoming increasingly urgent. In this study, Raman, Fourier transform infrared (FTIR), and energy‐dispersive X‐ray fluorescence spectroscopy (EDXRF) were performed to distinguish samples of inky jade from the two localities. The Raman spectra revealed the presence of several types of minor minerals in Guatemalan samples, including titanite, albite, orthoclase, taramite, celsian, and cymrite, whereas the Myanmar samples consisted almost entirely of omphacite. Taramite and lath‐like celsian occurred only in Guatemalan samples and had significance in locality tracing. The Raman and FTIR reflectance spectra of omphacite shifted to low wavenumbers in proportional to isomorphic substitution Na+Al3+ → Ca2+(Mg2+, Fe2+). Semiquantitative calculations based on the Raman (~680 cm−1) and IR modes (~658, ~576, and ~424 cm−1) showed consistent jadeite end‐member components (~43% to ~64%) in the Myanmar samples, whereas those (~23% to ~87.5%) of the Guatemalan samples were wider and generally lower. In addition, the full width at half maximum values (FWHMs) of Raman shifts near 680 cm−1 in the Myanmar samples (avg. 15.03 cm−1) were less than those (avg. 16.81 cm−1) of the Guatemalan specimens. Linear discriminant analysis (LDA) based on Raman spectroscopy identified most samples with accuracy of 85.5%. Combined with results by EDXRF, these analyses revealed the characteristics of a relatively narrow range of Na+Al3+ → Ca2+Mg2+ isomorphism for the Myanmar jades and a more developed Na+Al3+ → Ca2+(Mg2+, Fe2+) isomorphism for the Guatemalan jades. This study might have implications for commercial applications, archeological research, and judicial expertise.

Lattice vibrational characteristics and structure-property relationships of Ca(Mg1/2W1/2)O3 microwave dielectric ceramics with different sintering temperatures

Ca(Mg 1/2 W 1/2 )O 3 (CMW) microwave dielectric ceramics were synthesized by the solid state reaction method and were sintered at the temperatures in the range of 1450–1550 °C for 4 h. X-ray diffraction and Rietveld refinement results confirmed that the main phase of the samples belongs to the monoclinic crystal structure (P2 1 /c space group). The vibrational modes were determined using the Raman scattering and Fourier transform infrared reflection (FTIR) spectra, and the lattice vibrational characteristics were revealed in detail. The fitting curves of FTIR spectra were obtained by the four-parameter semi-quantum model that was used to calculate the intrinsic properties of samples, and the influence of the infrared mode on the intrinsic properties was elucidated. The structure-property relationships were constructed based on the Raman modes. The optimal dielectric properties of CMW ceramics are of ε r = 18.37, tanδ = 2.71 × 10 −4 and were obtained for the sintering temperature of 1500 °C.

Evaluation of the solubility of 11-keto-β-boswellic acid and its histological effect on the diabetic mice liver using a novel technique

Background and Aim:The literature is scant on the effect of 11-keto-β-boswellic acid (KBA) on the liver of diabetes-induced mice. This study was designed to develop a rapid, sensitive, accurate, and inexpensive detection technique for evaluating the solubility of KBA obtained from the gum resin of Omani frankincense (Boswellia sacra) in the liver of streptozotocin-induced diabetic mice using Fourier transform infrared (FTIR) reflectance spectroscopy coupled with principal components analysis (PCA). It also aimed to investigate the effect of KBA on histological changes in the hepatocytes of diabetic mice.Materials and Methods:Eighteen mice were assigned to the healthy control group, the diabetic control group, or the KBA-treated diabetic group. Liver tissue samples from all groups were scanned using an FTIR reflectance spectrophotometer in reflection mode. FTIR reflectance spectra were collected in the wavenumber range of 400-4000 cm−1 using an attenuated total reflectance apparatus.Results:FTIR reflectance spectra were analyzed using PCA. The PCA score plot, which is an exploratory multivariate data set, revealed complete segregation among the three groups’ liver samples based on changes in the variation of wavenumber position in the FTIR reflectance spectra, which indicated a clear effect of KBA solubility on treatments. Histological analysis showed an improvement in the liver tissues, with normal structures of hepatocytes exhibiting mild vacuolation in their cytoplasm.Conclusion:KBA improved the morphology of liver tissues in the diabetic mice and led to complete recovery of the damage observed in the diabetic control group. FTIR reflectance spectroscopy coupled with PCA could be deployed as a rapid, low-cost, and non-destructive detection method for evaluating treatment effects in diseased liver tissue based on the solubility of KBA.

UV-visible-infrared spectral survey of Antarctic carbonaceous chondrite chips

Antarctic carbonaceous chondrite (CC) meteorite chip samples in the Japanese and US collections have been studied by an ultraviolet (UV), visible (Vis), and near-infrared (NIR) (UVVNIR) spectrometer and a Fourier-transform infrared (FTIR) spectrometer, targeting small areas of about 2–6 mm in diameter. UVVNIR and FTIR reflectance spectra of 169 spots on 148 CC chips were measured on their naturally broken surfaces with no sample preparation. Among them, 83 spectra were accepted as reasonably free of terrestrial weathering or surface texture effects. X-ray diffraction (XRD) and FTIR measurements of a weathered sample revealed that gypsum likely formed on its surface after recovery from Antarctica. Principal component analysis (PCA) of the UVVNIR-FTIR combined spectra allowed distinguishing powder and chip or surface texture and identifying their class and thermal metamorphism. Gaussian fitting of the 3 μm absorption band of hydrous CC samples allowed for removal of the spectral effects of adsorbed H2O and for the extraction of structural absorption bands which are characteristic of CC classes and degree of aqueous alteration. These results suggest that CC-like rocks on small asteroids without fine regolith can be identified through spectral reflectance measurements by spacecraft, landers, or rovers.

Mechanisms of Caromatic-C bonds cleavage in lignin over NbOx-supported Ru catalyst

Efficient and selective cleavage of Caromatic-C linkages in lignin to enhance the productivity of monocyclic aromatic hydrocarbons is an extremely challenging and attractive task. Previously, we reported a Ru/NbOPO4 catalyst that realized the catalytic cleavage of both interunit C-C and C-O bonds in one-pot lignin conversions [Chem, 2019, 5, 1521–1536]. However, the roles of NbOx species in the selective Caromatic-C cleavage are not clear and need to be extensively studied. Herein, we focus on the exploration of the catalytic mechanisms of Caromatic-C bond cleavage over NbOx-supported Ru catalyst, by comparing with those of Ru/TiO2, Ru/ZrO2, and Ru/Al2O3 catalysts. It shows that the Ru/Nb2O5 catalyst exhibits high activity and remarkable selectivity to monocyclic hydrocarbons. A combined diffuse reflectance infrared Fourier Transform spectra (DRIFTS) and density functional theory (DFT) calculation analysis unambiguously confirmed that (i) NbOx not only can strongly adsorb phenylcyclohexane via benzene ring, but also selectively activate Caromatic-C bond between benzene ring and cyclohexane; (ii) NbOx can promote the protonation of phenylcyclohexane with the assistance of H3PO4; and (iii) NbOx can significantly reduce the barrier of Caromatic-C bonds cleavage of the carbocation intermediate (C6H5(H)C6H11+). A detail underlying mechanism has been established, which would have further implications to promote the design of new, high efficient catalysts.

Morphology control in PVDF membranes using PEG/PVP additives and mixed solvents

The effects of the mixed two solvents, Dimethylacetamide (DMAc) and Dimethylformamide (DMF), and Polyethylene glycol (PEG) and Polyvinylpyrrolidone (PVP) as additives on performance of Polyvinylidene fluoride (PVDF) membranes were studied. Initially, PEG200 was used as a primary additive at fixed percentage of 5% wt. PVP was then blended with PEG200 in different concentrations. PVDF and DMAc were used as polymer and solvent in the casting solutions, respectively. To control the diffusion rate of PVP in the presence of PEG200 and PVP blend, mixtures of DMAc and DMF were used as the mixed solvent in the casting solutions. Asymmetric PVDF membranes were prepared via phase inversion process in a water bath and the effects of two additives and two solvents on the membrane morphology, pure water flux (PWF), hydrophilicity and rejection (R) were investigated. Attenuated Total Reflection Fourier Transform Infrared Spectra (ATR-FTIR) analysis was used to show the residual PVP on the surface of the membranes. Atomic Force Microscopy (AFM) was utilized to determine roughness of membrane surface. The use of mixed solvents in the casting solution resulted in reduction of PVP diffusion rate and increment of PEG diffusion rate. Eventually, PWF and R values reduced, while porosity and hydrophilicity increased.

Discrimination of tea varieties based on FTIR spectroscopy and an adaptive improved possibilistic c‐means clustering

In order to identify tea varieties quickly, efficiently, and nondestructively, an adaptive improved possibilistic c-means (AIPCM) clustering with the fuzzy Mahalanobis distance was proposed to classify the Fourier transform infrared reflectance (FTIR) spectra of tea samples. Three varieties of tea samples were scanned and FTIR spectra were acquired for 96 tea samples of different geographical origins using the FTIR-7600 infrared spectrometer. Multiple scatter correction was employed to eliminate light scattering of FTIR spectral data. After that, principal component analysis and linear discriminant analysis were applied to reduce the dimensionality of FTIR spectra and extract the discriminant information, respectively. Then, the data were clustered by several fuzzy clustering algorithms. AIPCM had the highest clustering accuracy and its accuracy achieved up to 98.5%. The experimental results showed that FTIR spectroscopy coupled with AIPCM clustering was superior in classification of tea varieties. Practical applications Tea is a popular healthy drink, but there are counterfeit tea products for lack of the effective detection and classification methods in the markets. For this reason, FTIR technique coupled with an AIPCM clustering was applied to the identification of tea varieties, and this method has the advantages of nondestructive, fast, and high accuracy. This study can provide an effective classification method for other foods.

Phase Transformation, Optical and Emission Performance of Zinc Silicate Glass-Ceramics Phosphor Derived from the ZnO–B2O3–SLS Glass System

A new transparent zinc silicate glass-ceramic was derived from the 55ZnO–5B2O3–40SLS glass system via a controlled heat-treatment method. The precursor glass sample was placed through the heat-treatment process at different temperatures to study the progress in phase transformation, optical performance and emission intensity of the zinc silicate glass-ceramics. For this project, material characterization was measured through several tests using densimeter and linear shrinkage measurement, X-ray diffraction (XRD), Fourier transform infrared reflection (FTIR), ultraviolet–visible (UV–Vis) and photoluminescence (PL) spectroscopy. The density and linear shrinkage measurements show that the density of the particular glass-ceramic samples increases with the progression of heating temperature. The XRD analysis displays the result in which the zinc silicate crystal starts to grow after the sample was treated at 700 °C. In addition, the FTIR spectra indicated that the crystallization of the zinc silicate phase occurred with the appearance of SiO4, ZnO4 and Si-O-Zn bands. UV–visible exhibited the small changes when the value for the optical band gap decreased from 3.867 to 3.423 eV, influenced by the temperature applied to the sample. Furthermore, the PL spectroscopy showed an enhancement of broad green emission at 534 nm upon the increased heat-treatment temperature. Thus, it can be concluded there is the progression of crystal growth as the heat-treatment temperature increased; three emission peaks appeared at 529, 570 and 682 nm for the green, yellow and red emissions, respectively.

Rapid intraoperative diagnosis of gynecological cancer by ATR-FTIR spectroscopy of fresh tissue biopsy.

A rapid and reliable intraoperative diagnostic technique to support clinical decisions was developed using Fourier-transform infrared (FTIR) spectroscopy. Twenty-six fresh tissue samples were collected intraoperatively from patients undergoing gynecological surgeries. Frozen section (FS) histopathology aimed to discriminate between malignant and benign tumors was performed, and attenuated total reflection (ATR) FTIR spectra were collected from these samples. Digital dehydration and principal component analysis and linear discriminant analysis (PCA-LDA) models were developed to classify samples into malignant and benign groups. Two validation schemes were employed: k-fold and "leave one out." FTIR absorption spectrum of a fresh tissue sample was obtained in less than 5 minutes. The fingerprint spectral region of malignant tumors was consistently different from that of benign tumors. The PCA-LDA discrimination model correctly classified the samples into malignant and benign groups with accuracies of 96% and 93% for the k-fold and "leave one out" validation schemes, respectively. We showed that a simple tissue preparation followed by ATR-FTIR spectroscopy provides accurate means for very rapid tumor classification into malignant and benign gynecological tumors. With further development, the proposed method has high potential to be used as an adjunct to the intraoperative FS histopathology technique.

Infrared chemical mapping of degradation products in cross-sections from paintings and painted objects

Paintings and painted objects are quite susceptible to degradation, as paint layers are usually composed of complex mixtures of materials that can participate in chemical degradation processes. The identification of the constituent materials in paint (including binders, pigments, and fillers) and the degradation products within paint layers is of particular importance to ensuring the conservation of paintings, by providing important information both about their material history as well as their state of conservation. Metal fatty acid salts (metal soaps) are degradation products that can form in situ from interactions between inorganic pigments and free fatty acids in oil-based binding media, and can cause significant condition issues in paintings. Fourier transform infrared (FTIR) spectroscopy is one of the leading analytical techniques for the study of metal soaps. In this article, the materials analysis of several cross-sections from paintings and painted objects from works in Canadian collections is presented. Recent results on the use of external reflection FTIR (R-FTIR) spectroscopy to identify and map the distribution of paint components and metal soap degradation products is presented. In particular, zinc, lead, calcium, and copper fatty acid salts were all readily identified in paint cross-sections by R-FTIR spectroscopy, along with several pigments and the oil binding medium. The results shown here are among the first detailed examinations of these metal soaps in paint cross-sections using R-FTIR spectroscopy. The use of highly polished samples in which specular reflection is dominant allowed for spectral transformations to be applied to generate transmission/absorption-like spectra which facilitated identification of these species. The distribution of these species across the cross-sections was mapped by integrating characteristic absorption features in the R-FTIR spectra. Attenuated total internal reflection (ATR) FTIR spectroscopy was also performed on several samples, which provided additional compositional details at the interface of paint layers and degradation products.

Investigation of the robust hydrothermal stability of Cu/LTA for NH3-SCR reaction

Recently copper ion-exchanged LTA zeolites were proved to be robust for NH3-SCR reaction. In this study, Cu/LTA catalysts with Si/Al = 15 and Cu/Al = 0.4 were synthesized via incipient wetness impregnation (IWI) method, following degreening/hydrothermal aging at different temperatures (750, 800, 850, 900 °C), and used to catalyze standard SCR, fast SCR and NH3/NO oxidation reactions. Catalysts were characterized with surface area/pore volume, powder X-Ray diffraction (XRD), nuclear magnetic resonance (NMR), H2-temperature programmed reduction (H2-TPR) and in situ Diffuse Reflectance Infrared Fourier Transform Spectra (DRIFTS). Through the BET surface areas, XRD and NMR results, it can be found that the framework structure stability of Cu/LTA catalysts during hydrothermal aging was outstanding, even after harsh aging at 900 °C. Moreover, various Cu species, including Z-Cu2+, Z-[Cu(OH)]+ and CuOx clusters, were quantified for Cu/LTA catalysts hydrothermally aged under various temperatures with H2-TPR and in situ DRIFTS. An imperative finding in this study is the exceptional hydrothermal stability of [Cu(OH)]+ and the gradual conversions of both Cu2+ and CuOx clusters to [Cu(OH)]+ with increasing aging temperature. It is worth noting that this phenomenon is exactly the opposite of Cu/SSZ-13. As it is known from the literature (Song et al., 2017), the formation of CuOx not only decreases the selectivity of NOx conversion, but also can cause deterioration of zeolite structure, since the ion-exchanged copper stabilizes the zeolite. This may also explain why the hydrothermal stability of Cu/LTA samples is outstanding.

Strong confinement of optical fields using localized surface phonon polaritons in cubic boron nitride.

Phonon polaritons (PhPs) are long-lived electromagnetic modes that originate from the coupling of infrared (IR) photons with the bound ionic lattice of a polar crystal. Cubic-boron nitride (cBN) is such a polar, semiconductor material which, due to the light atomic masses, can support high-frequency optical phonons. Here we report on random arrays of cBN nanostructures fabricated via an unpatterned reactive ion etching process. Fourier-transform infrared reflection spectra suggest the presence of localized surface PhPs within the reststrahlen band, with quality factors in excess of 38 observed. These can provide the basis of next-generation IR optical components such as antennas for communication, improved chemical spectroscopies, and enhanced emitters, sources, and detectors.

Removal of benzothiophene and dibenzothiophene from hydrocarbon fuels using CuCe mesoporous Y zeolites in the presence of aromatics

Adsorptive desulfurization of sulfur compounds in transportation fuels, such as benzothiophenes from gasoline and jet fuels and dibenzothiophenes from diesel, can be inhibited by diffusion limitations in porous materials as well as the presence of aromatic hydrocarbons. In this study we demonstrate that adsorptive desulfurization using bimetal-exchanged mesoporous Y zeolites can overcome these challenges without sacrificing high sulfur adsorption capacity. The mesopores shorten the diffusion path length toward the internal active sites of the zeolite, while the metals (in this study Ce and Cu), not only create relatively stronger bonds, but also multiple adsorption configurations. The bimetallic mesoporous Y zeolites were prepared using a templated top-down approach, followed by the introduction of the metals, Cu and Ce, via ion-exchange. The ability of each zeolite to remove sulfur compounds is demonstrated by fixed-bed experiments. Model fuels were prepared using benzothiophene and dibenzothiophene in octane, benzene and naphthalene. The adsorption mechanisms of benzothiophene and dibenzothiophene were further studied, at the molecular level, using in-situ Diffuse Reflectance Infrared Fourier Transform Spectra (DRIFTS). Our results indicate that the metals display high affinity for the aforementioned sulfur compounds, via either π-complexation or σbond interaction. Specifically, Ce-exchanged Y zeolites exhibit multiple adsorption modes, as they can adsorb the sulfur compounds via the both configurations. Furthermore, the mesoporosity in Y zeolites enable the adsorption of dibenzothiophene with a diffusion coefficient of 4.5x greater than the parent Y zeolite. In conclusion, bimetallic mesoporous Y zeolites exhibited DBT capacity of almost 50 mL/g, five times more than parent Y, due to both improved mass transfer and high adsorption energy.

Discrimination of tea varieties using FTIR spectroscopy and allied Gustafson-Kessel clustering

For the purpose of classifying tea varieties, allied Gustafson-Kessel (AGK) clustering was proposed to cluster the Fourier transform infrared reflectance (FTIR) spectra of tea samples. As a fuzzy clustering algorithm, AGK can not only produce fuzzy membership and typicality values but also cluster various shapes of data with the help of Gustafson-Kessel (GK) clustering. After FTIR spectra were collected by FTIR-7600 infrared spectrometer, they were preprocessed with multiple scatter correction (MSC). To reduce the dimensionality of FTIR spectra and make the classification of data easily, principal component analysis (PCA) and linear discriminant analysis (LDA) were used to process the FTIR spectra. After that, fuzzy c-means (FCM) clustering, possibilistic c-means (PCM) clustering, AGK clustering and allied fuzzy c-means (AFCM) clustering were performed to cluster data, respectively. The clustering accuracy of AGK achieved 93.9% which was the highest one than other fuzzy clustering algorithms. The results obtained in experiments showed that AGK coupled with FTIR spectroscopy could provide an effective discrimination model for classification of tea varieties successfully.

Predicting the cell-wall compositions of Pinus radiata (radiata pine) wood using ATR and transmission FTIR spectroscopies

Because plant cell walls vary in their polysaccharide compositions and lignin contents, their monosaccharide compositions and lignin contents are often determined, but these analyses are time consuming and laborious. We therefore investigated Fourier transform infrared (FTIR) spectroscopy coupled with partial least squares (PLS) regression analysis as a way of rapidly predicting the monosaccharide compositions and lignin contents of the cell walls of compression wood (CW) and opposite wood (OW) of the gymnosperm Pinus radiata. The effects were investigated of sample moisture content (ambient or dry) and sample particle size (large particles, < 0.422 mm or small particles, < 0.178 mm) of milled wood on attenuated total reflectance (ATR) and transmission FTIR spectra, as well as the PLS-1 models and subsequent predictions. PLS-1 models were built using mixtures of CW and OW as the training set, to provide a linear range of monosaccharide compositions and lignin contents. Models were externally validated by predicting another set of wood mixtures before predicting CW and OW of a separate test set. Most of the monosaccharide amounts in the separate test set were best predicted by ATR spectroscopy of ambient large particles, achieving the lowest standard error values for the monosaccharides arabinose (0.36%), xylose (1.05%), galactose (1.79%), glucose (6.32%), and 4-O-methylglucuronic acid (0.20%). The results show the feasibility of using ATR spectroscopy of ambient large particles for the rapid prediction of monosaccharide compositions and lignin contents of plant cell walls.

In vitro oxidative degradation of a spinal posterior dynamic stabilization device.

This study quantified the changes of the frequency-dependant viscoelastic properties of the BDyn (S14 Implants, Pessac, France) spinal posterior dynamic stabilization (PDS) device due to in vitro oxidation. Six polycarbonate urethane (PCU) rings and six silicone cushions were degraded using a 20% hydrogen peroxide/0.1 M cobalt (II) chloride hexahydrate, at 37°C, for 24 days. The viscoelastic properties of the individual components and the components assembled into the BDyn PDS device were determined using Dynamic Mechanical Analysis at frequencies from 0.01 to 30 Hz. Attenuated Total Reflectance Fourier Transform Infra-Red spectra demonstrated chemical structure changes, of the PCU, associated with oxidation while Scanning Electron Microscope images revealed surface pitting. No chemical structure or surface morphology changes were observed for the silicone cushion. The BDyn device storage and loss stiffness ranged between 84.46 N/mm to 99.36 N/mm and 8.13 N/mm to 21.99 N/mm, respectively. The storage and loss stiffness for the components and BDyn device increased logarithmically with respect to frequency. Viscoelastic properties, between normal and degraded components, were significantly different for specific frequencies only. This study demonstrates the importance of analyzing changes of viscoelastic properties of degraded biomaterials and medical devices into which they are incorporated, using a frequency sweep. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1237-1244, 2018.

Rapid Quantitative Analysis of Forest Biomass Using Fourier Transform Infrared Spectroscopy and Partial Least Squares Regression.

Fourier transform infrared reflectance (FTIR) spectroscopy has been used to predict properties of forest logging residue, a very heterogeneous feedstock material. Properties studied included the chemical composition, thermal reactivity, and energy content. The ability to rapidly determine these properties is vital in the optimization of conversion technologies for the successful commercialization of biobased products. Partial least squares regression of first derivative treated FTIR spectra had good correlations with the conventionally measured properties. For the chemical composition, constructed models generally did a better job of predicting the extractives and lignin content than the carbohydrates. In predicting the thermochemical properties, models for volatile matter and fixed carbon performed very well (i.e., R 2 > 0.80, RPD > 2.0). The effect of reducing the wavenumber range to the fingerprint region for PLS modeling and the relationship between the chemical composition and higher heating value of logging residue were also explored. This study is new and different in that it is the first to use FTIR spectroscopy to quantitatively analyze forest logging residue, an abundant resource that can be used as a feedstock in the emerging low carbon economy. Furthermore, it provides a complete and systematic characterization of this heterogeneous raw material.

Structural and optical properties of Eu3+ activated low cost zinc soda lime silica glasses

A low cost method was employed to synthesize ZnO-SLS:xEu3+ phosphors using recyclable bottle glass as silica source. The structural and optical properties of ZnO-SLS:xEu3+ (x=0, 1, 2, 3, 4 and 5wt.%) glasses were determined using X-ray diffraction (XRD), Fourier transform infrared reflectance (FTIR), UV-visible (Uv-Vis) and photoluminescence (PL) spectroscopy. Structural investigation using XRD measurement had broadened the halo peak with the doping of dopants. FTIR spectra showed the glass system consists of –OH and SiO4 bands. Meanwhile, the optical measurement using UV-Vis absorption has been induced a blue shift of the electronic absorption edge. The emission peak intensity of ZnO-SLS:xEu3+ phosphors was enhanced with the progression of doping concentration and thus, revealed their potential as red emitting phosphors under 400nm excitation.