Journal of Spectroscopy http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Corrosion Performance of AISI-309 Exposed to Molten Salts V2O5-Na2SO4 at 700°C Applying EIS and Electrochemical Techniques Tue, 14 Apr 2015 11:05:55 +0000 http://www.hindawi.com/journals/jspec/2015/826759/ The corrosion performance of AISI-309 exposed 5 days to molten salts 50 mol% V2O5-50 mol% Na2SO4 at 700°C is reported in this paper. Such evaluation was made using three electrochemical techniques: potentiodynamic polarization curve (), electrochemical impedance spectroscopy (EIS), and linear polarization resistance (). From , the Tafel slopes, , and were obtained. From Nyquist and Bode plots, it was possible to determine two different stages; the first one showed just one loop, which indicated the initial formation of Cr2O3 layer over the metallic surface; after that, the dissolution of Cr2O3 formed a porous layer, which became part of the corrosion products; at the same time a NiO layer combined with sulfur was forming, which was suggested as the second stage, represented by two capacitive loops. EIS plots were in agreement with the physical characterization made from SEM and EDS analyses. Fitting of EIS experimental data allowed us to propose two electrical circuits, being in concordance with the corrosion stages. Parameters obtained from the simulation of EIS data are also reported. From the results, it was stated that AISI-309 suffered intergranular corrosion due to the presence of sulfur, which diffused to the metallic surface through a porous Cr2O3 layer. E. F. Diaz, C. Cuevas-Arteaga, N. Flores-García, S. Mejía Sintillo, and O. Sotelo-Mazón Copyright © 2015 E. F. Diaz et al. All rights reserved. On the Structural Analysis of -Ray Induced Primary Free Radicals in UHMWPE and Vitamin E Stabilized UHMWPE by ESR Spectroscopy Sun, 05 Apr 2015 11:29:15 +0000 http://www.hindawi.com/journals/jspec/2015/653853/ Oriented allyl radicals are detected at room temperature in gamma irradiated UHMWPE. The effects of vitamin E and storage at room temperature on this oriented structure are also investigated during the study. While testing powder as well as compression-molded solids, with or without vitamin E, a typical ESR spectrum was recorded at room temperature following 100 kGy gamma dose and subsequent storage at −78.5°C for one year. The simulated results show that the relative abundance of 5% alkyl, 68% allyl, and 27% polyenyl produced a 98.7% best fit of experimental ones. Furthermore, the allyl radical signal gives approximately 20% of random orientations and 80% of oriented molecules. In oriented PE, measured at −196°C, Ohnishi et al. (1916) observed 25 lines within a total magnetic field width of approximately 133 G. Our spectra also show 25 lines spread over 136 G in UHMWPE powder samples and at room temperature after one year of storage. Malik Sajjad Mehmood, Muhammad Shah Jahan, Tariq Yasin, Muhammad Tariq, Mohammad Ahmad Choudhry, and Masroor Ikram Copyright © 2015 Malik Sajjad Mehmood et al. All rights reserved. GC-FID and NMR Spectroscopic Studies on Gamma Irradiated Walnut Lipids Tue, 31 Mar 2015 14:30:54 +0000 http://www.hindawi.com/journals/jspec/2015/532762/ Walnuts have an excellent fatty acid profile, beneficial for coronary heart diseases. A diet rich in walnuts has shown to decrease the total and LDL cholesterol levels as well as lipoprotein levels. In this study, the effects of different doses of γ-irradiation and different packaging conditions on proximate composition and fatty acid profile of walnuts (Juglans regia L.) were investigated merging data from different spectroscopic techniques. Walnuts moisture, ash, fat, and protein content as well as fatty acid profile were evaluated immediately after irradiation. GC-FID results showed that SFA increased and MUFA and PUFA decreased with the increase of irradiation dose. Moreover, MUFA/SFA and PUFA/SFA ratios decreased compared to control samples. Furthermore, NMR spectroscopy was implemented to examine possible discrimination patterns based on irradiation dose and packaging. This approach revealed the role of PUFA decrease with the parallel increase of irradiation dose while indicating the protective role of vacuum and MAP compared to air packaging. In conclusion, at irradiation doses of up to 5 kGy, the walnuts retained the nutritional benefits of its fatty acids, in particular MUFA and PUFA. Concerning the different types of packaging, greater stability in the nuts was observed using MAP packaging. Vassilia J. Sinanoglou, Irini F. Strati, Katerina Kokkotou, Dimitra Lantzouraki, Constantinos Makris, and Panagiotis Zoumpoulakis Copyright © 2015 Vassilia J. Sinanoglou et al. All rights reserved. Effect of Salicylic Acid and 5-Sulfosalicylic Acid on UV-Vis Spectroscopic Characteristics, Morphology, and Contact Angles of Spin Coated Polyaniline and Poly(4-aminodiphenylaniline) Thin Films Tue, 31 Mar 2015 05:57:11 +0000 http://www.hindawi.com/journals/jspec/2015/609175/ Polyaniline and poly(4-aminodiphenyl)aniline have been prepared following two different synthetic protocols (a traditional method and a “green” method). Both the polymers have been spin coated with salicylic acid and 5-sulfosalicylic acid as the dopants, in order to obtain them in form of thin films. These materials have been characterized, thereof achieving important information on their water contact angles and surface morphology. A. Sironi, D. Marinotto, C. Riccardi, S. Zanini, E. Guerrini, C. Della Pina, and E. Falletta Copyright © 2015 A. Sironi et al. All rights reserved. Using Fourier Transform Infrared Spectroscopy to Study Effects of Magnetic Field Treatment on Wheat (Triticum aestivum L.) Seedlings Mon, 30 Mar 2015 11:27:23 +0000 http://www.hindawi.com/journals/jspec/2015/570190/ Magnetic field treatments have been utilized to promote germination and growth of a variety of species of plants; however the mechanism of concern has not been fully elucidated. In this research, wheat seedlings were treated with 500 mT and 1500 mT static magnetic field (SMF) for 10 and 20 min, respectively. Analyzing Fourier transform infrared spectra collected from leaves of seedlings showed that SMF treatments decreased the contents of lipids and proteins, shifted bands to higher wavenumbers in 3000–2800 cm−1 regions, and increased the ratio of CH2/CH3 which likely indicates a structural variation of lipids. For bands assigned to different second structures of proteins, slight bands shifting and changing the ratio of different second structures of proteins were observed due to SMF treatments. To summarize, the results revealed that lipids rather than proteins were sensitive to SMF treatments. The results provided insight into the SMF induced conformational changes of lipids and proteins in wheat leaves, which will help elucidate the biological mechanisms of SMF on plant growth and development. Zhenlin Wei, Dejie Jiao, and Junxiao Xu Copyright © 2015 Zhenlin Wei et al. All rights reserved. Spectroscopy Applied to Engineering Materials Thu, 26 Mar 2015 07:32:56 +0000 http://www.hindawi.com/journals/jspec/2015/693276/ Ming-Guo Ma, Wen Zeng, Shao-Wen Cao, Zhong-Chang Wang, and Jie-Fang Zhu Copyright © 2015 Ming-Guo Ma et al. All rights reserved. XPS, FTIR, EDX, and XRD Analysis of Al2O3 Scales Grown on PM2000 Alloy Wed, 25 Mar 2015 11:38:12 +0000 http://www.hindawi.com/journals/jspec/2015/868109/ This work is an original example to compare the results obtained after calcination of Al2O3 hydroxides and oxidation of alumino-formers alloys. FTIR and XPS signatures were obtained for various oxidation temperatures and compared with those known from the literature about calcination of Al2O3 precursors. The aim of this work is to evaluate the use of IR spectroscopy and XPS analysis to probe the structural varieties of Al2O3. For this objective, a study of the PM2000 oxidation at various temperatures was conducted by means of XRD, IR spectroscopy, XPS analysis, EDX analysis, and SEM observations. This allowed us to clearly differentiate the transition Al2O3 from the α-Al2O3 and, amongst the transition Al2O3, to differentiate the characteristic of the IR spectrum of γ-δ phases from that of the θ phase. K. Djebaili, Z. Mekhalif, A. Boumaza, and A. Djelloul Copyright © 2015 K. Djebaili et al. All rights reserved. Atomic Force Microscopy for Understanding Solvent Cointercalation into Graphite Electrode in Lithium Secondary Batteries Wed, 25 Mar 2015 08:38:41 +0000 http://www.hindawi.com/journals/jspec/2015/462140/ The electrochemical processes occurring at the surface of a highly ordered pyrolytic graphite (HOPG) electrode were investigated by in situ atomic force microscopy (AFM) to understand the solvent cointercalation involved in the formation of a surface film. AFM images were recorded under the conditions that AFM probe does not affect the electrode reaction. The AFM images show the morphological changes occurring at the electrode surface, indicating that two different types of reactions occurred in the film formation at the surface of the electrode. The formation of a blister structure was observed on the graphite surface, because of the decomposition of solvated lithium ions produced in the electrolyte solution and intercalation between the graphite layer and particulate materials. The solvent cointercalation reaction leading to the blister structure was more pronounced for the HOPG electrode with a higher value of mosaic spread. Yang-Soo Kim and Soon-Ki Jeong Copyright © 2015 Yang-Soo Kim and Soon-Ki Jeong. All rights reserved. The Improvement Effect of Dispersant in Fluorite Flotation: Determination by the Analysis of XRD and FESEM-EDX Wed, 25 Mar 2015 08:07:36 +0000 http://www.hindawi.com/journals/jspec/2015/859365/ Different dispersants were added in the dispersion process to improve the efficiency of fluorite flotation. The types and dosage of dispersant on the improvement of fluorite flotation were investigated; when the sodium polyacrylate (SPA) was used as the dispersant and its addition is 0.5%, the concentrate grade of CaF2 increased from 90% to 98% and the fluorite recovery increased from 81% to 85%. Methods of X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), and Energy dispersive X-ray spectrometer (EDX) were used to characterize the sample. According to the analysis of results, the optimal sample consisted of CaF2 and very little CaCO3 in the size range of 0–5 μm. It could be concluded that the mechanism of improvement for the concentrate grade and recovery of CaF2 was attributed to the change of potential energy barrier which caused the separation of particles with different charge. All results indicate that SPA has a great potential to be an efficient and cost-effective dispersant for the improvement of fluorite flotation. Y. J. Li, F. Y. Sun, Y. Zhou, and L. Zeng Copyright © 2015 Y. J. Li et al. All rights reserved. EPR Spectroscopy Investigation of Cu2+ Ions Adsorbed in Tannin-Formaldehyde Resins of Mimosa (Acacia mearnsii) Bark Extracts Tue, 24 Mar 2015 13:46:29 +0000 http://www.hindawi.com/journals/jspec/2015/978270/ The chemical environment of Cu2+ ions adsorbed in tannin-formaldehyde resins of Acacia mearnsii bark extracts, prepared from polybutene, is investigated by EPR spectroscopy at 300 K. The spectrum is simulated considering two isolated axial Cu(II) species (Species 1: , , , and ; Species 2: , , , and ), superposed to a broad line (; linewidth = 30.0(5) mT) assigned to Cu(II) aggregates. Measurements at 77 K did not improve spectral resolution. Heating at 413 K changes the hyperfine parameters of Species 2 (, , , and ) and slightly modifies the parameters of the broad line (; linewidth = 40.00(50) mT) but does not change Species 1, assigned to Cu(II) species immobilized into resin pores in cathecolate-type coordination sites. Species 2 is assigned to Cu(II) species immobilized at the outer resin surface. Upon extended heating, a reversible formation of semiquinone-type paramagnetic radicals () is observed, assigned to the partial collapse of the resin polymeric network. Marcelo H. Herbst and Ney V. Vugman Copyright © 2015 Marcelo H. Herbst and Ney V. Vugman. All rights reserved. Insight into the Interaction between the HIV-1 Integrase Inhibitor Elvitegravir and Bovine Serum Albumin: A Spectroscopic Study Tue, 24 Mar 2015 12:30:06 +0000 http://www.hindawi.com/journals/jspec/2015/435674/ The interaction between the anti-HIV drug Elvitegravir (EVG) and bovine serum albumin (BSA) was investigated by fluorescence spectroscopy and UV-visible absorption spectra. The mechanism for quenching the fluorescence of BSA by EVG is discussed. It was found that EVG can quench the intrinsic fluorescence of BSA through a static quenching procedure. The quenching type, association constant, and number of binding sites were investigated. The binding constant of EVG with BSA was calculated at different temperatures based on fluorescence quenching results. The thermodynamic parameters , , and were determined. The positive and negative and values showed that a spontaneous interaction may involve both roles of hydrophobic interaction and hydrogen bonding. The interaction of BSA with EVG was also confirmed by UV absorption spectra. The average distance, , between donor (BSA) and acceptor (EVG) was obtained according to Förster’s theory of nonradiation energy transfer. Synchronous fluorescence and three-dimensional fluorescence spectra were used to investigate the conformational change of BSA molecules that occur upon addition of EVG and showed, upon binding, a possibility of increasing hydrophobicity around tryptophan residues of BSA. Ali Saber Abdelhameed Copyright © 2015 Ali Saber Abdelhameed. All rights reserved. Detection of Dissolved Carbon Monoxide in Transformer Oil Using 1.567 m Diode Laser-Based Photoacoustic Spectroscopy Tue, 24 Mar 2015 10:12:42 +0000 http://www.hindawi.com/journals/jspec/2015/737635/ Carbon monoxide (CO) is one of the most important fault characteristic gases dissolved in power transformer oil. With the advantages of high sensitivity and accuracy, long-term stability, and short detection time, photoacoustic spectroscopy (PAS) has been proven to be one promising sensing technology for trace gas recognition. In this investigation, a tunable PAS experimental system based on a distributed-feedback (DFB) diode laser was proposed for recognizing dissolved CO in transformer oil. The molecular spectral line of CO gas detection was selected at 1.567 μm in the whole experiment. Relationships between the photoacoustic (PA) signal and gas pressure, temperature, laser power, and CO gas concentration were measured and discussed in detail, respectively. Finally, based on the least square regression theory, a novel quantitative identification method for CO gas detection with the PAS experimental system was proposed. And a comparative research about the gas detection performances performed by the PAS system and gas chromatography (GC) measurement was presented. All results lay a solid foundation for exploring a portable and tunable CO gas PAS detection device for practical application in future. Qu Zhou, Chao Tang, Shiping Zhu, Weigen Chen, and Xiaojuan Peng Copyright © 2015 Qu Zhou et al. All rights reserved. Hydrothermal Synthesis and Structural Characterization of NiO/SnO2 Composites and Hydrogen Sensing Properties Tue, 24 Mar 2015 09:13:17 +0000 http://www.hindawi.com/journals/jspec/2015/450485/ Pure SnO2 and NiO doped SnO2 nanostructures were successfully synthesized via a simple and environment-friendly hydrothermal method. X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectra (XPS) were used to investigate the crystalline structures, surface morphologies and microstructures, and element components and their valences of the as-synthesized samples. Furthermore, planar chemical gas sensors based on the synthesized pure SnO2 and NiO/SnO2 composites were fabricated and their sensing performances to hydrogen, an important fault characteristic gas dissolved in power transformer oil, were investigated in detail. Gas sensing experiments indicate that the NiO/SnO2 composites showed much higher gas response and lower working temperature than those of pure SnO2, which could be ascribed to the formation of p-n heterojunctions between p-type NiO and n-type SnO2. These results demonstrate that the as-synthesized NiO/SnO2 composites a promising hydrogen sensing material. Chao Wei, Bin Bo, Fengbo Tao, Yuncai Lu, Shudi Peng, Wei Song, and Qu Zhou Copyright © 2015 Chao Wei et al. All rights reserved. Evaluation of Salmon Adhesion on PET-Metal Interface by ATR, FT-IR, and Raman Spectroscopy Tue, 24 Mar 2015 06:55:45 +0000 http://www.hindawi.com/journals/jspec/2015/835798/ The material employed in this study is an ecoefficient, environmentally friendly, chromium (VI)-free (noncarcinogenic) metal polymer. The originality of the research lies in the study of the effect of new production procedures of salmon on metal packaging with multilayer polyethylene terephthalate (PET) polymer coatings. Our hypothesis states that the adhesion of postmortem salmon muscles to the PET polymer coating produces surface and structural changes that affect the functionality and limit the useful life of metal containers, compromising therefore their recycling capacity as ecomaterials. This work is focused on studying the effects of the biochemical changes of postmortem salmon on the PET coating and how muscle degradation favors adhesion to the container. The experimental design considered a series of laboratory tests of containers simulating the conditions of canned salmon, chemical and physical tests of food-contact canning to evaluate the adhesion, and characterization of changes in the multilayer PET polymer by electron microscopy, ATR, FT-IR, and Raman spectroscopy analyses. The analyses determined the effect of heat treatment of containers on the loss of freshness of canned fish and the increased adhesion to the container wall, and the limited capability of the urea treatment to remove salmon muscle from the container for recycling purposes. E. Zumelzu, M. J. Wehrhahn, F. Rull, H. Pesenti, O. Muñoz, and R. Ugarte Copyright © 2015 E. Zumelzu et al. All rights reserved. Orientation Mapping of Extruded Polymeric Composites by Polarized Micro-Raman Spectroscopy Tue, 24 Mar 2015 06:43:03 +0000 http://www.hindawi.com/journals/jspec/2015/518054/ Molecular orientation has a strong influence on polymeric composite materials’ mechanical properties. In this paper we describe the use of polarized micro-Raman spectroscopy as a powerful tool to map out the molecular orientation of a uniaxially oriented polypropylene- (PP-) based composite material. Initial samples exhibited a high degree of surface fibrillation upon cutting. Raman spectroscopy was used to characterize the degree of orientation in the skin and guide the development of the posttreatment process to optimize the skin relaxation while maintaining the high degree of orientation in the rest of the board. The PP oriented polymer composite (OPC) was oriented through an extrusion process and its surface was then treated to achieve relaxation. Micro-Raman analysis at the surface region demonstrated the surface orientation relaxation, and the results provide an effective way to correlate the extent of relaxation and process conditions. Larger scale orientation mapping was also carried out over the entire cross-section (12.7 cm × 2.54 cm). The results agree well with prior expectation of the molecular orientation based on the extrusion and subsequent quenching process. The methodologies described here can be readily applied to other polymeric systems. Xiaoyun Chen, M. Anne Leugers, Tim Kirch, and Jamie Stanley Copyright © 2015 Xiaoyun Chen et al. All rights reserved. NIRS Characterization of Paper Pulps to Predict Kappa Number Mon, 23 Mar 2015 13:15:10 +0000 http://www.hindawi.com/journals/jspec/2015/104609/ Rice is one of the most abundant food crops in the world and its straw stands as an important source of fibres both from an economic and an environmental point of view. Pulp characterization is of special relevance in works involving alternative raw materials, since pulp properties are closely linked to the quality of the final product. One of the analytical techniques that can be used in pulp characterization is near-infrared spectroscopy (NIRS). The use of NIRS has economic and technical advantages over conventional techniques. This paper aims to discuss the convenience of using NIRS to predict Kappa number in rice straw pulps produced under different conditions. We found that the resulting Kappa number can be acceptably estimated by NIRS, as the errors obtained with that method are similar to those found for other techniques. Ana Moral, Elena Cabeza, Roberto Aguado, and Antonio Tijero Copyright © 2015 Ana Moral et al. All rights reserved. Research on Fluorescence Spectroscopy Characteristics of Dissolved Organic Matter of Landfill Leachate in the Rear Part of Three Gorges Reservoir Mon, 23 Mar 2015 13:06:38 +0000 http://www.hindawi.com/journals/jspec/2015/785406/ Three-dimensional fluorescence and infrared spectroscopy analysis of the leachate dissolved organic matter (DOM) of the Three Gorges was reported in spring, summer, and autumn seasons, respectively. Studies show that, that organic matter of landfill leachate in Yongchuan, Dazu and Jiangjin is the class of fulvic-like acid and protein-like fluorescence. The study also found that the longer the time of the pile of garbage, the lower the content of class of protein-like concentration, and the higher the concentration of fulvic-like acid, indicating that the protein waste material in the humification process is easy degradation. However, the same source of DOM is similar in the functional group composition and molecular structure. Characteristic frequency area analysis showed that humic acids (HA), and fulvic acids (FA) contain more than hydrophilic organic matter (HyI) aromatic ring structure, and FA aromatic ring structure is the most. Because of Chung-amide NH deformation vibration, there are strong absorption peaks in the 1562~1572 cm−1 for various components; HyI contains many organic nitrogen compounds and fatty acids. Zhigang Xie and Wei Guan Copyright © 2015 Zhigang Xie and Wei Guan. All rights reserved. Monitoring of Spectral Map Changes from Normal State to Superconducting State in High- Superconductor Films Using Raman Imaging Mon, 23 Mar 2015 13:05:54 +0000 http://www.hindawi.com/journals/jspec/2015/276537/ We have explored the chemical structure of TlBa2Ca2Cu3O9 high- superconductor films with Tl-1223 phase to monitor spectral map changes from normal state to superconducting state using the technique of Raman imaging. Raman images were performed for 12 different temperatures in the 77–293 K range. At room temperature, the Raman images were characterized by a single color but as the temperature dropped a new color appeared and when the temperature of 77 K is reached and the superconducting state is assured, the Raman images were characterized by the red, green, and blue colors. Our study could suggest that the superconducting state emerged around 133 K, in full agreement with those reported in the literature. A cross-checking was done applying principal component analysis (PCA) to other sets of Raman spectra of our films measured at different temperatures. PCA result showed that the spectra can be grouped into two temperature ranges, one in the 293–153 K range and the other in the 133–77 K range suggesting that transition to the superconducting state occurred at some temperature around 133 K. This is the first report of preliminary results evaluating the usefulness of Raman imaging in determination of transition temperature of superconductor films. J. L. González-Solís, R. Sánchez-Ruiz, I. A. Arana-Zamora, J. C. Martínez-Espinosa, M. L. Pérez-Arrieta, and C. Falcony-Guajardo Copyright © 2015 J. L. González-Solís et al. All rights reserved. Binding Cellulose and Chitosan via Intermolecular Inclusion Interaction: Synthesis and Characterisation of Gel Mon, 23 Mar 2015 11:39:46 +0000 http://www.hindawi.com/journals/jspec/2015/179258/ A novel cellulose-chitosan gel was successfully prepared in three steps: (1) ferrocene- (Fc-) cellulose with degrees of substitution (DS) of 0.5 wt% was synthesised by ferrocenecarboxylic acid and cellulose within dimethylacetamide/lithium chloride (DMAc/LiCl); (2) the β-cyclodextrin (β-CD) groups were introduced onto the chitosan chains by reacting chitosan with epichlorohydrin in dimethyl sulphoxide and a DS of 0.35 wt%; (3) thus, the cellulose-chitosan gel was obtained via an intermolecular inclusion interaction of Fc-cellulose and β-CD-chitosan in DMA/LiCl, that is, by an intermolecular inclusion interaction, between the Fc groups of cellulose and the β-CD groups on the chitosan backbone at room temperature. The successful synthesis of Fc-cellulose and β-CD-chitosan was characterised by 13C-NMR spectroscopy. The gel based on β-CD-chitosan and Fc-cellulose was formed under mild conditions which can engender autonomous healing between cut surfaces after 24 hours: the gel cannot self-heal while the cut surfaces were coated with a solution of a competitive guest (adamantane acid). The cellulose-chitosan complex made by this method underwent self-healing. Therefore, this study provided a novel method of expanding the application of chitosan by binding it with another polymer. Jiufang Duan, Chunrui Han, Liujun Liu, Jianxin Jiang, Jianzhang Li, Yiqiang Li, and Chao Guan Copyright © 2015 Jiufang Duan et al. All rights reserved. Excitation Induced Tunable Emission in Ce3+/Eu3+ Codoped BiPO4 Nanophosphors Tue, 17 Mar 2015 08:17:36 +0000 http://www.hindawi.com/journals/jspec/2015/493607/ Ce3+, Eu3+ ions singly doped, and Ce3+/Eu3+ codoped bismuth phosphate (BiPO4) nanophosphors were synthesized by a simple precipitation method and their structural, morphological, and photoluminescence properties were investigated. The structural and morphological analysis confirms the pure hexagonal crystal structure of the synthesized nanophosphors. From the Fourier transform infrared (FTIR) spectra various absorption bands respective to functional groups such as PO4 and phonon vibrations including the bending modes of the PO4 units are identified. The Ce3+ doped nanophosphors show spectrally broad luminescence in the blue (centred at 459 nm) wavelength region under the direct optical excitation of Ce3+ at 417 nm. For Eu3+ doped nanophosphors, five emission bands have been observed with 394 nm excitation wavelength. Among them, 595 nm has shown bright yellowish-orange emission. These results demonstrate that by appropriately tuning the excitation wavelength of these codoped nanophosphors the emission color in the visible region (blue and orange) can be flexibly controlled in a single sample without varying its chemical composition and size. The mechanism for this excitation energy dependent tunable emission is explained on the basis of nonenergy transfer (ET) occurring among Ce3+/Eu3+ dopant ions. Sarabjot Singh, G. Lakshminarayana, Manoj Sharma, Thang Duy Dao, K. Chen, Yoshiki Wada, T. Takeda, and T. Nagao Copyright © 2015 Sarabjot Singh et al. All rights reserved. Ultrafast Probe of Carrier Diffusion and Nongeminate Processes in a Single CdSSe Nanowire Thu, 12 Mar 2015 13:41:44 +0000 http://www.hindawi.com/journals/jspec/2015/574754/ We measure ultrafast carrier dynamics in a single CdSSe nanowire at different excitation fluences using an ultrafast Kerr-gated microscope. The time-resolved emission exhibits a dependence on excitation fluence, with the onset of the emission varying on the picosecond time scale with increasing laser power. By fitting the emission to a model for amplified spontaneous emission (ASE), we are able to extract the nonradiative carrier recombination lifetime and nongeminate recombination constant. The extracted nongeminate recombination constant suggests that our measurement technique allows the access to the nondiffusion limited recombination regime in nanowires with low carrier mobility. Peter S. Eldridge, Jolie C. Blake, and Lars Gundlach Copyright © 2015 Peter S. Eldridge et al. All rights reserved. Oxide Nanolayers in Stratified Samples Studied by X-Ray Resonant Raman Scattering at Grazing Incidence Tue, 10 Mar 2015 06:49:06 +0000 http://www.hindawi.com/journals/jspec/2015/618279/ X-ray resonant Raman scattering is applied at grazing incidence conditions with the aim of discriminating and identifying chemical environment of iron in different layers of stratified materials using a low resolution energy dispersive system. The methodology allows for depth studies with nanometric resolution. Nanostratified samples of Fe oxides were studied at the Brazilian synchrotron facility (LNLS) using monochromatic radiation and an EDS setup. The measurements were carried out in grazing incident regime with incident photon energy lower than and close to the Fe-K absorption edge. The result allowed for characterizing oxide nanolayers, not observable with conventional geometries, identifying the oxidation state present in a particular depth of a sample surface with nanometric, or even subnanometric, resolution using a low-resolution system. Juan José Leani, Héctor Jorge Sánchez, and Carlos Alberto Pérez Copyright © 2015 Juan José Leani et al. All rights reserved. The Effect of Highly Hydroxylated Fullerenol C60(OH)36 on Human Erythrocyte Membrane Organization Mon, 09 Mar 2015 08:54:56 +0000 http://www.hindawi.com/journals/jspec/2015/825914/ The mechanism of the interaction of highly hydroxylated fullerenol C60(OH)36 with erythrocyte membranes was studied by electron spin resonance spectroscopy (ESR) of stearic acid derivatives labeled with a nitroxyl radical at C-12 or C-16 and with a nitroxyl derivative of maleimide covalently attached to sulfhydryl groups of membrane proteins. A significant increase in membrane fluidity in the hydrophobic region of the lipid bilayer was observed for 12-doxylstearic acid at fullerenol concentrations of 100 mg/L or 150 mg/L, while for 16-doxylstearic acid significant increase in fluidity was only observed at 150 mg/L. Fullerenol at 100 mg/L or 150 mg/L caused conformational changes in membrane proteins, expressed as an increase in the hw/hs parameter, when fullerenol was added before the maleimide spin label (MSL) to the membrane suspension. The increase of the hw/hs parameter may be caused by changes in lipid-protein or protein-protein interactions which increase the mobility of the MSL label and as a result increase the membrane fluidity. Incubation of the membranes with the MSL before the addition of fullerenol blocked the available membrane protein –SH groups and minimized the interaction of fullerenol with them. This confirms that fullerenol interacts with erythrocyte membrane proteins via available protein –SH groups. Jacek Grebowski and Anita Krokosz Copyright © 2015 Jacek Grebowski and Anita Krokosz. All rights reserved. Midinfrared FT-IR as a Tool for Monitoring Herbaceous Biomass Composition and Its Conversion to Furfural Wed, 04 Mar 2015 13:59:36 +0000 http://www.hindawi.com/journals/jspec/2015/719042/ A semiquantitative analysis by means of midinfrared FT-IR spectroscopy was tuned for the simultaneous determination of cellulose, hemicellulose, and lignin in industrial crops such as giant reed (Arundo donax L.) and switchgrass (Panicum virgatum L.). Ternary mixtures of pure cellulose, hemicellulose, and lignin were prepared and a direct correlation area/concentration was achieved for cellulose and lignin, whereas indirect correlations were found for hemicellulose quantification. Good correspondences between the values derived from our model and those reported in the literature or obtained according to the official Van Soest method were ascertained. Average contents of 40–45% of cellulose, 20–25% of hemicellulose, and 20–25% of lignin were obtained for different samples of giant reed species. In the case of switchgrass, a content of 36% of cellulose, 28% of hemicellulose, and 26% of lignin was achieved. This analysis was also carried out on giant reed and switchgrass residues after a mild hydrolysis step carried out with dilute hydrochloric acid for the production of furfural with good yield. Reasonable compositional data were obtained, thus allowing an indirect monitoring which helps the optimization of the hydrothermal pretreatment for furfural production from hemicellulose fractions. Anna Maria Raspolli Galletti, Aldo D’Alessio, Domenico Licursi, Claudia Antonetti, Giorgio Valentini, Alessandro Galia, and Nicoletta Nassi o Di Nasso Copyright © 2015 Anna Maria Raspolli Galletti et al. All rights reserved. Oxidative Stability of Baru (Dipteryx alata Vogel) Oil Monitored by Fluorescence and Absorption Spectroscopy Wed, 04 Mar 2015 11:25:48 +0000 http://www.hindawi.com/journals/jspec/2015/803705/ Baru (Dipteryx alata Vogel) is a native fruit of the Brazilian savanna that provides a nutritive oil, which also has medicinal properties. Baru fruits were collected in central-western Brazil, and the oil was obtained by pressing the seeds. The Baru oil was heated at 110°C for 24 h, and its oxidative stability was investigated by using fluorescence and absorption spectroscopy. The data showed that both absorption and fluorescence were able to precisely monitor the oil degradation induced by the thermooxidative process. The results revealed a rapid growth of the primary compounds generation in the first 16 hours of degradation. Significant amounts of secondary compounds began to be generated after 14 hours. Vanessa D. Silva, José N. Conceição, Ivan P. Oliveira, Caroline H. Lescano, Rozanna M. Muzzi, Omar P. S. Filho, Edemilson C. Conceição, Gleison A. Casagrande, and Anderson R. L. Caires Copyright © 2015 Vanessa D. Silva et al. All rights reserved. Effect of the Unsaturation of the Hydrocarbon Chain of Fatty-Amides on the Corrosion of Carbon Steel Using EIS and Real-Time Corrosion Measurement Mon, 02 Mar 2015 09:32:17 +0000 http://www.hindawi.com/journals/jspec/2015/184140/ Fatty-amide derivatives were evaluated to study the effect of the double bonds into the hydrocarbon chain (C18) on the corrosion behavior of carbon steel. Electrochemical impedance spectroscopy (EIS) and real-time corrosion measurements were used to evaluate the inhibition mechanism of the fatty-amides on carbon steel in CO2-saturated (3% NaCl + 10% diesel) emulsion at 50°C. EIS results demonstrated that the unsaturation present into the hydrocarbon chain contributes to the efficiency of fatty-amides, because they can be adsorbed on the metal surface by a flat-adsorption process reducing the presence of active sites and blocking the corrosion process and preventing the diffusion of corrosive species, such as H2O, H+, Cl−, and . Real-time corrosion measurements also indicated that the effectiveness of the inhibitors is dependent on the unsaturation into the hydrocarbon chain, being also a good technique to determine the stability of the adsorption process of the inhibitors. J. Porcayo-Calderon, I. Regla, E. Vazquez-Velez, L. M. Martinez de la Escalera, J. Canto, and M. Casales-Diaz Copyright © 2015 J. Porcayo-Calderon et al. All rights reserved. A Simple Approach to Distinguish Classic and Formaldehyde-Free Tannin Based Rigid Foams by ATR FT-IR Thu, 26 Feb 2015 10:22:03 +0000 http://www.hindawi.com/journals/jspec/2015/902340/ Tannin based rigid foams (TBRFs) have been produced with formaldehyde since 1994. Only recently several methods have been developed in order to produce these foams without using formaldehyde. TBRFs with and without formaldehyde are visually indistinguishable; therefore a method for determining the differences between these foams had to be found. The attenuated total reflectance infrared spectroscopy (ATR FT-IR) investigation of the TBRFs presented in this paper allowed discrimination between the formaldehyde-containing (classic) and formaldehyde-free TBRFs. The spectra of the formaldehyde-free TBRFs, indeed, present decreased band intensity related to the C–O stretching vibration of (i) the methylol groups and (ii) the furanic rings. This evidence served to prove the chemical difference between the two TBRFs and explained the slightly higher mechanical properties measured for the classic TBRFs. Gianluca Tondi, Martin Link, Chuan Wei Oo, and Alexander Petutschnigg Copyright © 2015 Gianluca Tondi et al. All rights reserved. Fourier Transform Infrared Spectroscopic Imaging of Fracture Healing in the Normal Mouse Thu, 26 Feb 2015 06:34:38 +0000 http://www.hindawi.com/journals/jspec/2015/659473/ Fourier transform infrared spectroscopic imaging (FTIRI) was used to study bone healing with spatial analysis of various callus tissues in wild type mice. Femoral fractures were produced in 28 male C57BL mice by osteotomy. Animals were sacrificed at 1, 2, 4, and 8 weeks to obtain callus tissue at well-defined healing stages. Following microcomputerized tomography, bone samples were cut in consecutive sections for FTIRI and histology, allowing for spatial correlation of both imaging methods in different callus areas (early calcified cartilage, woven bone, areas of intramembranous and endochondral bone formation). Based on FTIRI, mineral/matrix ratio increased significantly during the first 4 weeks of fracture healing in all callus areas and correlated with bone mineral density measured by micro-CT. Carbonate/phosphate ratio was elevated in newly formed calcified tissue and at week 2 attained values comparable to cortical bone. Collagen maturity and mineral crystallinity increased during weeks 1–8 in most tissues while acid phosphate substitution decreased. Temporal and callus area dependent changes were detected throughout the healing period. These data assert the usefulness of FTIRI for evaluation of fracture healing in the mouse and its potential to evaluate pathologic fracture healing and the effects of therapeutic interventions. Hans Gollwitzer, Xu Yang, Lyudmila Spevak, Lyudmila Lukashova, Allina Nocon, Kara Fields, Nancy Pleshko, Hayden William Courtland, Mathias P. Bostrom, and Adele L. Boskey Copyright © 2015 Hans Gollwitzer et al. All rights reserved. Green Synthesis and Characterization of Carbon Nanotubes/Polyaniline Nanocomposites Mon, 23 Feb 2015 14:46:10 +0000 http://www.hindawi.com/journals/jspec/2015/297804/ Carbon nanotubes/polyaniline (CNT/PANI) nanocomposites were synthesized by the interfacial polymerization of aniline in the presence of CNTs using two green solvents, water and an ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF4]), as the two phases. The formation and incorporation of PANI on the surface of the CNTs were confirmed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy ultraviolet-visible spectroscopy, and X-ray photoelectron spectroscopy. The analyses showed that the surface of the CNTs was coated with different morphologies of thin PANI layers depending on whether a HCl or HNO3 solution was used. The thermal stability of the composites was much better than that of the bare CNTs and pure PANI. The as-prepared composites were also used to modify the nickel foam electrodes for characterization of the electrochemical properties. Van Hoa Nguyen and Jae-Jin Shim Copyright © 2015 Van Hoa Nguyen and Jae-Jin Shim. All rights reserved. SrAl2O4:Eu2+(,Dy3+) Nanosized Particles: Synthesis and Interpretation of Temperature-Dependent Optical Properties Mon, 23 Feb 2015 07:58:58 +0000 http://www.hindawi.com/journals/jspec/2015/541958/ SrAl2O4 nanosized particles (NPs) undoped as well as doped with Eu2+ and Dy3+ were prepared by combustion synthesis for the discussion of their intensively debated spectroscopic properties. Emission spectra of SrAl2O4:Eu2+(,Dy3+) NPs are composed by a green band at 19 230 cm−1 (520 nm) at room temperature, assigned to anomalous luminescence originated by Eu2+ in this host lattice. At low temperatures, a blue emission band at 22 520 cm−1 (444 nm) is observed. Contrary to most of the interpretations provided in the literature, we assign this blue emission band very reliably to a normal 4f6(7FJ)5d(t2g)→4f7(8S7/2) transition of Eu2+ substituting the Sr2+ sites. This can be justified by the presence of a fine structure in the excitation spectra due to the different 7FJ levels () of the 4f6 core. Moreover, Fano antiresonances with the 6IJ () levels could be observed. In addition, the Stokes shifts ( 980 cm−1 and 5 270 cm−1 for the blue and green emission, resp.), the Huang-Rhys parameters of and 6, and the average phonon energies of and 470 cm−1 coupled with the electronic states could be reliably determined. Huayna Terraschke, Markus Suta, Matthias Adlung, Samira Mammadova, Nahida Musayeva, Rasim Jabbarov, Mihail Nazarov, and Claudia Wickleder Copyright © 2015 Huayna Terraschke et al. All rights reserved.