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Sample records for raman spectroscopic investigations

  1. Dual Raman-Brillouin spectroscopic investigation of plant stress response and development

    Science.gov (United States)

    Coker, Zachary; Troyanova-Wood, Maria; Marble, Kassie; Yakovlev, Vladislav

    2018-03-01

    Raman and Brillouin spectroscopy are powerful tools for non-invasive and non-destructive investigations of material chemical and mechanical properties. In this study, we use a newly developed custom-built dual Raman-Brillouin microspectroscopy instrument to build on previous works studying in-vivo stress response of live plants using only a Raman spectroscopy system. This dual Raman-Brillouin spectroscopy system is capable of fast simultaneous spectra acquisition from single-point locations. Shifts and changes in a samples Brillouin spectrum indicate a change in the physical characteristics of the sample, namely mechano-elasticity; in measuring this change, we can establish a relationship between the mechanical properties of a sample and known stress response agents, such as reactive oxygen species and other chemical constituents as indicated by peaks in the Raman spectra of the same acquisition point. Simultaneous application of these spectroscopic techniques offers great promise for future development and applications in agricultural and biological studies and can help to improve our understanding of mechanochemical changes of plants and other biological samples in response to environmental and chemically induced stresses at microscopic or cellular level.

  2. Raman and photoelectron spectroscopic investigation of high-purity niobium materials: Oxides, hydrides, and hydrocarbons

    Science.gov (United States)

    Singh, Nageshwar; Deo, M. N.; Nand, Mangla; Jha, S. N.; Roy, S. B.

    2016-09-01

    We present investigations of the presence of oxides, hydrides, and hydrocarbons in high-purity (residual resistivity ratio, ˜300) niobium (Nb) materials used in fabrication of superconducting radio frequency (SRF) cavities for particle accelerators. Raman spectroscopy of Nb materials (as-received from the vendor as well as after surface chemical- and thermal processing) revealed numerous peaks, which evidently show the presence of oxides (550 cm-1), hydrides (1277 and 1385 cm-1: ˜80 K temperature), and groups of hydrocarbons (1096, 2330, 2710, 2830, 2868, and 3080 cm-1). The present work provides direct spectroscopic evidence of hydrides in the electropolished Nb materials typically used in SRF cavities. Raman spectroscopy thus can provide vital information about the near-surface chemical species in niobium materials and will help in identifying the cause for the performance degradation of SRF cavities. Furthermore, photoelectron spectroscopy was performed on the Nb samples to complement the Raman spectroscopy study. This study reveals the presence of C and O in the Nb samples. Core level spectra of Nb (doublet 3d5/2 and 3d3/2) show peaks near 206.6 and 209.4 eV, which can be attributed to the Nb5+ oxidation state. The core level spectra of C 1 s of the samples are dominated by graphitic carbon (binding energy, 284.6 eV), while the spectra of O 1 s are asymmetrically peaked near binding energy of ˜529 eV, and that indicates the presence of metal-oxide Nb2O5. The valence-band spectra of the Nb samples are dominated by a broad peak similar to O 2p states, but after sputtering (for 10 min) a peak appears at ˜1 eV, which is a feature of the elemental Nb atom.

  3. Raman and terahertz spectroscopical investigation of cocrystal formation process of piracetam and 3-hydroxybenzoic acid

    Science.gov (United States)

    Du, Yong; Zhang, Huili; Xue, Jiadan; Fang, Hongxia; Zhang, Qi; Xia, Yi; Li, Yafang; Hong, Zhi

    2015-03-01

    Cocrystallization can improve physical and chemical properties of active pharmaceutical ingredient, and this feature has great potential in pharmaceutical development. In this study, the cocrystal of piracetam and 3-hydroxybenzoic acid under grinding condition has been characterized by Raman and terahertz spectroscopical techniques. The major vibrational modes of individual starting components and cocrystal are obtained and assigned. Spectral results show that the vibrational modes of the cocrystal are different from those of the corresponding parent materials. The dynamic process of such pharmaceutical cocrystal formation has also been monitored directly with Raman and THz spectra. The formation rate is pretty fast in first several 20 min grinding time, and then it becomes slow. After ∼35 min, such process has been almost completed. These results offer us the unique means and benchmark for characterizing the cocrystal conformation from molecule-level and also provide us rich information about the reaction dynamic during cocrystal formation process in pharmaceutical fields.

  4. Investigation into structure and dehydration dynamic of gallic acid monohydrate: A Raman spectroscopic study.

    Science.gov (United States)

    Cai, Qiang; Xue, Jiadan; Wang, Qiqi; Du, Yong

    2018-05-02

    The dehydration process of gallic acid monohydrate was carried out by heating method and characterized using Raman spectroscopic technique. Density functional theory calculation with B3LYP function is applied to simulate optimized structures and vibrational frequencies of anhydrous gallic acid and its corresponding monohydrated form. Different vibrational modes are assigned by comparison between experimental and theoretical Raman spectra of above two polymorphs. Raman spectra show that vibrational modes of the monohydrate are distinctively different from those of anhydrous one. Meanwhile, the dynamic information about dehydration process of gallic acid monohydrate could also be observed and monitored directly with the help of Raman spectral analysis. The decay rate of the characteristic band from gallic acid monohydrate and the growth rate of anhydrous one are pretty consistent with each other. It indicates that there is no intermediate present during the dehydration process of gallic acid monohydrate. The results could offer us benchmark works for identifying both anhydrous and hydrated pharmaceutical compounds, characterizing their corresponding molecular conformation within various crystalline forms, and also providing useful information about the process of dehydration dynamic at the microscopic molecular level. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Raman spectroscopic investigations of swift heavy ion irradiation effects in single-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Olejniczak, A.; Skuratov, V.A.; Lukaszewicz, J.P.

    2013-01-01

    In this study, we report the results on swift heavy ion irradiation effects in single-walled carbon nanotubes (SWNTs). Buckypapers, prepared of CVD grown, SWNTs were irradiated at room temperature with 167 MeV Xe ions to fluences in the range of 6×10 11 - 6.5×10 13 cm -2 and investigated using Raman spectroscopy. We observed a rich set of features in the intermediate frequency mode region. Some of them, being defect-induced, resembled fairly well the phonon density of states (DOS) of nanocrystalline glassy carbon. Analysis of the RBM modes has shown that the broader metallic tubes are characterized by higher radiation stability than thinner semiconducting ones. (authors)

  6. Raman Spectroscopic Studies of Methane Gas Hydrates

    DEFF Research Database (Denmark)

    Hansen, Susanne Brunsgaard; Berg, Rolf W.

    2009-01-01

    A brief review of the Raman spectroscopic studies of methane gas hydrates is given, supported by some new measurements done in our laboratory.......A brief review of the Raman spectroscopic studies of methane gas hydrates is given, supported by some new measurements done in our laboratory....

  7. A micro-Raman spectroscopic investigation of leukemic U-937 cells in aged cultures

    Science.gov (United States)

    Fazio, Enza; Trusso, Sebastiano; Franco, Domenico; Nicolò, Marco Sebastiano; Allegra, Alessandro; Neri, Fortunato; Musolino, Caterina; Guglielmino, Salvatore P. P.

    2016-04-01

    Recently it has been shown that micro-Raman spectroscopy combined with multivariate analysis is able to discriminate among different types of tissues and tumoral cells by the detection of significant alterations and/or reorganizations of complex biological molecules, such as nucleic acids, lipids and proteins. Moreover, its use, being in principle a non-invasive technique, appears an interesting clinical tool for the evaluation of the therapeutical effects and of the disease progression. In this work we analyzed molecular changes in aged cultures of leukemia model U937 cells with respect to fresh cultures of the same cell line. In fact, structural variations of individual neoplastic cells on aging may lead to a heterogeneous data set, therefore falsifying confidence intervals, increasing error levels of analysis and consequently limiting the use of Raman spectroscopy analysis. We found that the observed morphological changes of U937 cells corresponded to well defined modifications of the Raman contributions in selected spectral regions, where markers of specific functional groups, useful to characterize the cell state, are present. A detailed subcellular analysis showed a change in cellular organization as a function of time, and correlated to a significant increase of apoptosis levels. Besides the aforementioned study, Raman spectra were used as input for principal component analysis (PCA) in order to detect and classify spectral changes among U937 cells.

  8. Visible-IR and Raman micro-spectroscopic investigation of three Itokawa particles collected by Hayabusa

    Science.gov (United States)

    Brunetto, R.; Bonal, L.; Beck, P.; Dartois, E.; Dionnet, Z.; Djouadi, Z.; Füri, E.; Kakazu, Y.; Oudayer, P.; Quirico, E.; Engrand, C.

    2014-07-01

    HAYABUSA grains offer a unique perspective to better understand the link between asteroids and cosmomaterials available in the laboratory and to get an insight on the early stages of surface space weathering. The scientific objectives of our consortium are threefold: (i) the characterization of asteroidal surface processes (e.g., space weathering alteration); (ii) the assessment of parent-body alteration processes; (iii) the search for a possible association between S-type asteroids and micrometeorites. To this aim, our strategy is based on a combination of analytical techniques. Here we report a first series of results obtained through Visible-Infrared and Raman spectroscopy of three Itokawa particles (RA-QD02-0163, -0174, and -0213) collected by the Hayabusa spacecraft and provided by JAXA for our consortium. In a first step, our main objective was to collect maximum information without altering the particles. Reported results were thus obtained on the raw particles, both (i) in their original containers, and (ii) deposited on diamond windows. Raman and IR confocal spectra were acquired at the SMIS beamline of the French national synchrotron facility SOLEIL and at the Lyon Raman national facility using spots of 2 μ m for the Raman, and 10--20 μ m for the IR analyses. Point analyses and automatic mapping were performed. Analytical parameters (e.g., laser power on the sample) were optimized to prevent any damage. Diffuse reflectance spectra (i=45°, e=0°) in the visible and near-IR wavelengths were obtained with an IAS-CSNSM in-home system coupling a fiber spectrometer to an optical microscope, providing a 20-μ m spot on sample. In the case of particle -0163, Raman and IR results reveal a heterogeneous mixing of minerals, mostly olivine (Fo76), and Ca-rich (En50, Wo50) and Ca-poor (En85) pyroxenes. The modal distribution of these minerals is determined based on the spectral maps. The mineral compositions of -0163 are consistent with those previously reported on

  9. Raman and Terahertz Spectroscopic Investigation of Cocrystal Formation Involving Antibiotic Nitrofurantoin Drug and Coformer 4-aminobenzoic Acid

    Directory of Open Access Journals (Sweden)

    Yong Du

    2016-12-01

    Full Text Available Cocrystallization could improve most physicochemical properties of specific active pharmaceutical ingredients, which has great potential in pharmaceutical development. In this study, the cocrystal of nitrofurantoin and 4-aminobenzoic acid was prepared with solid-state (solvent-free or green-chemistry grinding approach, and the above cocrystal has been characterized by Raman and terahertz vibrational spectroscopic techniques. Spectral results show that the vibrational modes of the cocrystal within the whole spectral region are different from those of the corresponding parent materials. The dynamic process of such pharmaceutical cocrystal formation has also been monitored directly with Raman spectra. These results offer us unique means for characterizing the cocrystal conformation from the molecule-level, and provides us with rich information about the reaction dynamic of cocrystal formation within pharmaceutical fields.

  10. Raman spectroscopic investigation of superconducting YBa2Cu3O7/sub -//sub x/, semiconducting YBa2Cu3O6/sub +//sub x/, and possible impurity phases

    International Nuclear Information System (INIS)

    Mascarenhas, A.; Geller, S.; Xu, L.C.; Katayama-Yoshida, H.; Pankove, J.I.; Deb, S.K.

    1988-01-01

    A Raman spectroscopic investigation of specimens of superconducting YBa 2 Cu 3 O/sub 7-//sub x/ and of the possible impurity phases YBa 2 Cu 3 O/sub 6+//sub x/ (semiconductor), Y 2 BaCuO 5 , Y 2 Cu 2 O 5 , BaCuO 2 , CuO, Y 2 O 3 , and BaCO 3 indicates that in the range 100--700 cm -1 , there are six characteristic lines belonging to the superconductor. At 13 K, these lines are at 150, 338, 441, 507, 590, and 644 cm -1 . Comparison of the Raman spectra of the superconductor and the semiconductor indicates a mode stiffening of the pair at 338 and 441 cm -1 , but a mode softening of the pair at 507 and 590 cm -1 . A factor group analysis leads to a tentative assignment of the Raman and infrared allowed modes

  11. Raman spectroscopic studies on bacteria

    Science.gov (United States)

    Maquelin, Kees; Choo-Smith, Lin-P'ing; Endtz, Hubert P.; Bruining, Hajo A.; Puppels, Gerwin J.

    2000-11-01

    Routine clinical microbiological identification of pathogenic micro-organisms is largely based on nutritional and biochemical tests. Laboratory results can be presented to a clinician after 2 - 3 days for most clinically relevant micro- organisms. Most of this time is required to obtain pure cultures and enough biomass for the tests to be performed. In the case of severely ill patients, this unavoidable time delay associated with such identification procedures can be fatal. A novel identification method based on confocal Raman microspectroscopy will be presented. With this method it is possible to obtain Raman spectra directly from microbial microcolonies on the solid culture medium, which have developed after only 6 hours of culturing for most commonly encountered organisms. Not only does this technique enable rapid (same day) identifications, but also preserves the sample allowing it to be double-checked with traditional tests. This, combined with the speed and minimal sample handling indicate that confocal Raman microspectroscopy has much potential as a powerful new tool in clinical diagnostic microbiology.

  12. Raman spectroscopic biochemical mapping of tissues

    Science.gov (United States)

    Stone, Nicholas; Hart Prieto, Maria C.; Kendall, Catherine A.; Shetty, Geeta; Barr, Hugh

    2006-02-01

    Advances in technologies have brought us closer to routine spectroscopic diagnosis of early malignant disease. However, there is still a poor understanding of the carcinogenesis process. For example it is not known whether many cancers follow a logical sequence from dysplasia, to carcinoma in situ, to invasion. Biochemical tissue changes, triggered by genetic mutations, precede morphological and structural changes. These can be probed using Raman or FTIR microspectroscopy and the spectra analysed for biochemical constituents. Local microscopic distribution of various constituents can then be visualised. Raman mapping has been performed on a number of tissues including oesophagus, breast, bladder and prostate. The biochemical constituents have been calculated at each point using basis spectra and least squares analysis. The residual of the least squares fit indicates any unfit spectral components. The biochemical distribution will be compared with the defined histopathological boundaries. The distribution of nucleic acids, glycogen, actin, collagen I, III, IV, lipids and others appear to follow expected patterns.

  13. Raman spectroscopic studies of hydrogen clathrate hydrates.

    Science.gov (United States)

    Strobel, Timothy A; Sloan, E Dendy; Koh, Carolyn A

    2009-01-07

    Raman spectroscopic measurements of simple hydrogen and tetrahydrofuran+hydrogen sII clathrate hydrates have been performed. Both the roton and vibron bands illuminate interesting quantum dynamics of enclathrated H(2) molecules. The complex vibron region of the Raman spectrum has been interpreted by observing the change in population of these bands with temperature, measuring the absolute H(2) content as a function of pressure, and with D(2) isotopic substitution. Quadruple occupancy of the large sII clathrate cavity shows the highest H(2) vibrational frequency, followed by triple and double occupancies. Singly occupied small cavities display the lowest vibrational frequency. The vibrational frequencies of H(2) within all cavity environments are redshifted from the free gas phase value. At 76 K, the progression from ortho- to para-H(2) occurs over a relatively slow time period (days). The rotational degeneracy of H(2) molecules within the clathrate cavities is lifted, observed directly in splitting of the para-H(2) roton band. Raman spectra from H(2) and D(2) hydrates suggest that the occupancy patterns between the two hydrates are analogous, increasing confidence that D(2) is a suitable substitute for H(2). The measurements suggest that Raman is an effective and convenient method to determine the relative occupancy of hydrogen molecules in different clathrate cavities.

  14. Spectroscopic (far or terahertz, mid-infrared and Raman) investigation, thermal analysis and biological activity of piplartine

    Science.gov (United States)

    Srivastava, Anubha; Karthick, T.; Joshi, B. D.; Mishra, Rashmi; Tandon, Poonam; Ayala, A. P.; Ellena, Javier

    2017-09-01

    Research in the field of medicinal plants including Piper species like long pepper (Piper longum L.- Piperaceae) is increasing all over the world due to its use in traditional and Ayurvedic medicine. Piplartine (piperlongumine, 5,6-dihydro-1-[(2E)-1-oxo-3-(3,4,5-trimethoxyphenyl)-2-propenyl]-2(1H)-pyridinone), a biologically active alkaloid/amide was isolated from the phytochemical investigations of Piper species, as long pepper. This alkaloid has cytotoxic, anti-fungal, anti-diabetic, anti-platelet aggregation, anti-tumoral, anxiolytic, anti-depressant, anti-leishmanial, and genotoxic activities, but, its anticancer property is the most promising and has been widely explored. The main purpose of the work is to present a solid state characterization of PPTN using thermal analysis and vibrational spectroscopy. Quantum mechanical calculations based on the density functional theory was also applied to investigate the molecular conformation and vibrational spectrum, which was compared with experimental results obtained by Raman scattering, far (terahertz) and mid-infrared adsorption spectroscopy. NBO analysis has been performed which predict that most intensive interactions in PPTN are the hyperconjugative interactions between n(1) N6 and π*(O1sbnd C7) having delocalization energy of 50.53 kcal/mol, Topological parameters have been analyzed using 'AIM' analysis which governs the three bond critical points (BCPs), one di-hydrogen, and four ring critical points (RCPs). MEP surface has been plotted which forecast that the most negative region is associated with the electronegative oxygen atoms (sites for nucleophilic activity). Theoretically, to confirm that the title compound has anti-cancer, anti-diabetic and anti-platelet aggregation activities, it was analyzed by molecular docking interactions with the corresponding target receptors. The obtained values of H-bonding parameters and binding affinity prove that its anti-cancer activity is the more prominent than the

  15. Graphitic carbon nanospheres: A Raman spectroscopic investigation of thermal conductivity and morphological evolution by pulsed laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, Radhe; Sahoo, Satyaprakash, E-mail: satya504@gmail.com, E-mail: rkatiyar@hpcf.upr.edu; Chitturi, Venkateswara Rao; Katiyar, Ram S., E-mail: satya504@gmail.com, E-mail: rkatiyar@hpcf.upr.edu [Department of Physics, University of Puerto Rico, San Juan, Puerto Rico 00936-8377 (United States)

    2015-12-07

    Graphitic carbon nanospheres (GCNSs) were prepared by a unique acidic treatment of multi-walled nanotubes. Spherical morphology with a narrow size distribution was confirmed by transmission electron microscopy studies. The room temperature Raman spectra showed a clear signature of D- and G-peaks at around 1350 and 1591 cm{sup −1}, respectively. Temperature dependent Raman scattering measurements were performed to understand the phonon dynamics and first order temperature coefficients related to the D- and G-peaks. The temperature dependent Raman spectra in a range of 83–473 K were analysed, where the D-peak was observed to show a red-shift with increasing temperature. The relative intensity ratio of D- to G-peaks also showed a significant rise with increasing temperature. Such a temperature dependent behaviour can be attributed to lengthening of the C-C bond due to thermal expansion in material. The estimated value of the thermal conductivity of GCNSs ∼0.97 W m{sup −1} K{sup −1} was calculated using Raman spectroscopy. In addition, the effect of pulsed laser treatment on the GCNSs was demonstrated by analyzing the Raman spectra of post irradiated samples.

  16. Surface-enhanced Raman spectroscopic studies of the Au-pentacene interface: a combined experimental and theoretical investigation.

    Science.gov (United States)

    Adil, D; Guha, S

    2013-07-28

    It has recently been shown [D. Adil and S. Guha, J. Phys. Chem. C 116, 12779 (2012)] that a large enhancement in the Raman intensity due to surface-enhanced Raman scattering (SERS) is observed from pentacene when probed through the Au contact in organic field-effect transistors (OFET) structures. Here, the SERS spectrum is shown to exhibit a high sensitivity to disorder introduced in the pentacene film by Au atoms. The Raman signature of the metal-semiconductor interface in pentacene OFETs is calculated with density-functional theory by explicitly considering the Au-pentacene interaction. The observed enhancement in the 1380 cm(-1) and the 1560 cm(-1) regions of the experimental Raman spectrum of pentacene is successfully modeled by Au-pentacene complexes, giving insights into the nature of disorder in the pentacene sp(2) network. Finally, we extend our previous work on high-operating voltage pentacene OFETs to low-operating voltage pentacene OFETs. No changes in the SERS spectra before and after subjecting the OFETs to a bias stress are observed, concurrent with no degradation in the threshold voltage. This shows that bias stress induced performance degradation is, in part, caused by field-induced structural changes in the pentacene molecule. Thus, we confirm that the SERS spectrum can be used as a visualization tool for correlating transport properties to structural changes, if any, in organic semiconductor based devices.

  17. X-ray Photoelectron Spectroscopic and Raman microscopic investigation of the variscite group minerals: Variscite, strengite, scorodite and mansfieldite

    Science.gov (United States)

    Kloprogge, J. Theo; Wood, Barry J.

    2017-10-01

    Several structurally related AsO4 and PO4 minerals, were studied with Raman microscopy and X-ray Photoelectron Spectroscopy (XPS). XPS revealed only Fe, As and O for scorodite. The Fe 2p, As 3d, and O 1s indicated one position for Fe2 +, while 2 different environments for O and As were observed. The O 1s at 530.3 eV and the As 3d 5/2 at 43.7 eV belonged to AsO4, while minor bands for O 1s at 531.3 eV and As 3d 5/2 at 44.8 eV were due to AsO4 groups exposed on the surface possibly forming OH-groups. Mansfieldite showed, besides Al, As and O, a trace of Co. The PO4 equivalent of mansfieldite is variscite. The change in crystal structure replacing As with P resulted in an increase in the binding energy (BE) of the Al 2p by 2.9 eV. The substitution of Fe3 + for Al3 + in the structure of strengite resulted in a Fe 2p at 710.8 eV. An increase in the Fe 2p BE of 4.8 eV was found between mansfieldite and strengite. The scorodite Raman OH-stretching region showed a sharp band at 3513 cm- 1 and a broad band around 3082 cm- 1. The spectrum of mansfieldite was like that of scorodite with a sharp band at 3536 cm- 1 and broader maxima at 3100 cm- 1 and 2888 cm- 1. Substituting Al in the arsenate structure instead of Fe resulted in a shift of the metal-OH-stretching mode by 23 cm- 1 towards higher wavenumbers due to a slightly longer H-bonding in mansfieldite compared to scorodite. The intense band for scorodite at 805 cm- 1 was ascribed to the symmetric stretching mode of the AsO4. The medium intensity bands at 890, 869, and 830 cm- 1 were ascribed to the internal modes. A significant shift towards higher wavenumbers was observed for mansfieldite. The strengite Raman spectrum in the 900-1150 cm- 1 shows a strong band at 981 cm- 1 accompanied by a series of less intense bands. The 981 cm- 1 band was assigned to the PO4 symmetric stretching mode, while the weak band at 1116 cm- 1 was the corresponding antisymmetric stretching mode. The remaining bands at 1009, 1023 and 1035 cm- 1

  18. Raman spectroscopic studies on CeVO4 at high pressures

    International Nuclear Information System (INIS)

    Rao, Rekha; Garg, Alka B.; Wani, B.N.

    2011-01-01

    Raman scattering investigations of CeVO 4 at high pressures is reported. Polycrystalline CeVO 4 was prepared by solid state reaction of CeO 2 and V 2 O 5 . High pressure Raman spectroscopic measurements were carried out as per experimental details given

  19. Raman spectroscopic study of some chalcopyrite-xanthate flotation products

    CSIR Research Space (South Africa)

    Andreev, GN

    2003-12-16

    Full Text Available of normal vibrations of the corresponding individual compounds. The latter facilitated the Raman spectroscopic elucidation of the reaction products formed on the chalcopyrite surface in real industrial flotation conditions with a sodium isopropyl xanthate...

  20. Raman spectroscopic analysis identifies testicular microlithiasis as intratubular hydroxyapatite.

    Science.gov (United States)

    De Jong, B W D; De Gouveia Brazao, C A; Stoop, H; Wolffenbuttel, K P; Oosterhuis, J W; Puppels, G J; Weber, R F A; Looijenga, L H J; Kok, D J

    2004-01-01

    As diagnosed by ultrasonography, testicular microlithiasis is associated with various benign and malignant conditions. The molecular constitution of these microliths is largely unknown. Raman spectroscopy provides detailed in situ information about the molecular composition of tissues and to our knowledge it has not been applied to gonadal microliths. We analyzed the molecular composition of gonadal microlithiasis and its surrounding region using Raman spectroscopy in malignant and benign conditions. Multiple microliths from 6 independent samples diagnosed with gonadal microlithiasis by ultrasound and histologically confirmed were investigated by Raman spectroscopy. The samples included 4 testicular parenchyma samples adjacent to a germ cell tumor (4 seminomas), a gonadoblastoma of a dysgenetic gonad and testicular biopsy of a subfertile male without malignancy. Raman spectroscopic mapping demonstrated that testicular microliths were located within the seminiferous tubule. Glycogen surrounded all microliths in the samples associated with germ cell neoplasm but not in the benign case. The molecular composition of the 26 microliths in all 6 conditions was pure hydroxyapatite. Microliths in the testis are located in the seminiferous tubules and composed of hydroxyapatite. In cases of germ cell neoplasm they co-localize with glycogen deposits.

  1. Raman Spectroscopic Imaging of the Whole Ciona intestinalis Embryo during Development

    Science.gov (United States)

    Nakamura, Mitsuru J.; Hotta, Kohji; Oka, Kotaro

    2013-01-01

    Intracellular composition and the distribution of bio-molecules play central roles in the specification of cell fates and morphogenesis during embryogenesis. Consequently, investigation of changes in the expression and distribution of bio-molecules, especially mRNAs and proteins, is an important challenge in developmental biology. Raman spectroscopic imaging, a non-invasive and label-free technique, allows simultaneous imaging of the intracellular composition and distribution of multiple bio-molecules. In this study, we explored the application of Raman spectroscopic imaging in the whole Ciona intestinalis embryo during development. Analysis of Raman spectra scattered from C. intestinalis embryos revealed a number of localized patterns of high Raman intensity within the embryo. Based on the observed distribution of bio-molecules, we succeeded in identifying the location and structure of differentiated muscle and endoderm within the whole embryo, up to the tailbud stage, in a label-free manner. Furthermore, during cell differentiation, we detected significant differences in cell state between muscle/endoderm daughter cells and daughter cells with other fates that had divided from the same mother cells; this was achieved by focusing on the Raman intensity of single Raman bands at 1002 or 1526 cm−1, respectively. This study reports the first application of Raman spectroscopic imaging to the study of identifying and characterizing differentiating tissues in a whole chordate embryo. Our results suggest that Raman spectroscopic imaging is a feasible label-free technique for investigating the developmental process of the whole embryo of C. intestinalis. PMID:23977129

  2. Vibrational spectroscopic characterisation of salmeterol xinafoate polymorphs and a preliminary investigation of their transformation using simultaneous in situ portable Raman spectroscopy and differential scanning calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Hassan Refat H. [Chemical and Forensic Sciences/University Analytical Centre, School of Life Sciences, University of Bradford, Richmond Road, Bradford BD7 1DP (United Kingdom); Edwards, Howell G.M. [Chemical and Forensic Sciences/University Analytical Centre, School of Life Sciences, University of Bradford, Richmond Road, Bradford BD7 1DP (United Kingdom)], E-mail: H.G.M.Edwards@bradford.ac.uk; Hargreaves, Michael D.; Munshi, Tasnim; Scowen, Ian J.; Telford, Richard J. [Chemical and Forensic Sciences/University Analytical Centre, School of Life Sciences, University of Bradford, Richmond Road, Bradford BD7 1DP (United Kingdom)

    2008-07-14

    Knowledge and control of the polymorphic phases of chemical compounds are important aspects of drug development in the pharmaceutical industry. Salmeterol xinafoate, a long acting {beta}-adrenergic receptor agonist, exists in two polymorphic Forms, I and II. Raman and near infrared spectra were obtained of these polymorphs at selected wavelengths in the range of 488-1064 nm; significant differences in the Raman and near-infrared spectra were apparent and key spectral marker bands have been identified for the vibrational spectroscopic characterisation of the individual polymorphs which were also characterised with X ray diffractometry. The solid-state transition of salmeterol xinafoate polymorphs was studied using simultaneous in situ portable Raman spectroscopy and differential scanning calorimetry isothermally between transitions. This method assisted in the unambiguous characterisation of the two polymorphic forms by providing a simultaneous probe of both the thermal and vibrational data. The study demonstrates the value of a rapid in situ analysis of a drug polymorph which can be of potential value for at-line in-process control.

  3. Vibrational spectroscopic characterisation of salmeterol xinafoate polymorphs and a preliminary investigation of their transformation using simultaneous in situ portable Raman spectroscopy and differential scanning calorimetry

    International Nuclear Information System (INIS)

    Ali, Hassan Refat H.; Edwards, Howell G.M.; Hargreaves, Michael D.; Munshi, Tasnim; Scowen, Ian J.; Telford, Richard J.

    2008-01-01

    Knowledge and control of the polymorphic phases of chemical compounds are important aspects of drug development in the pharmaceutical industry. Salmeterol xinafoate, a long acting β-adrenergic receptor agonist, exists in two polymorphic Forms, I and II. Raman and near infrared spectra were obtained of these polymorphs at selected wavelengths in the range of 488-1064 nm; significant differences in the Raman and near-infrared spectra were apparent and key spectral marker bands have been identified for the vibrational spectroscopic characterisation of the individual polymorphs which were also characterised with X ray diffractometry. The solid-state transition of salmeterol xinafoate polymorphs was studied using simultaneous in situ portable Raman spectroscopy and differential scanning calorimetry isothermally between transitions. This method assisted in the unambiguous characterisation of the two polymorphic forms by providing a simultaneous probe of both the thermal and vibrational data. The study demonstrates the value of a rapid in situ analysis of a drug polymorph which can be of potential value for at-line in-process control

  4. Raman spectroscopic study of leptospiral glycolipoprotein

    Science.gov (United States)

    Bao, PeiDi; Bao, Lang; Huang, TianQuan; Liu, XinMing

    1998-04-01

    The Raman scattering spectra of two different samples of Leptospiral Glycoipoprotein (GLP-1 and GLP-2) which have different toxic effects have been obtained and investigated. Leptospirosis is one of the most harmful zoonosis. It is a serious public health issue in some area of Sichusan province. The two samples offer different structural informations of GLP molecules, it would be important to find the difference in contents, structures and the amino acid side - chains environment of the molecules between the two samples of GLP for understanding the different toxic effects. The intense Am I at 1651 cm-1 and weak Am III at 1283 cm-1 show that GLP-1 has a predominantly (alpha) -helix secondary structure. The intense Am I at 1674 cm-1 and intense Am III at 1246 cm-1 show that the conformation of GLP-2 has a high content of (Beta) - sheet and a low content of random - coil secondary structure. Strong Raman scattering occurs in the range 920- 980 cm-1, belong to the C-COO vibration and the stretching of the peptide backbone. The molecules of GLP-1 has trans-gauche-trans configuration of the C-S-S-C-C linkage and the molecules of GLP-2 has trans-gauche-gauche configuration of the C-C-S-S-C-C linkage. The intensity ratio of the two tyrosine liens at 830 cm-1 and 850 cm-1 is 1.1 and 1.23, indicate their tyrosine reduces environment respectively. Other side-chain environment in the two samples were discussed.

  5. INFRARED AND RAMAN SPECTROSCOPIC STUDY OF ION ...

    African Journals Online (AJOL)

    Infrared and Raman spectroscopy techniques have been used to study the ionic interactions of strontium(II) and barium(II) with thiocyanate ion in liquid ammonia. A number of bands were observed in both n (CN) and n (CS) regions of infrared and Raman spectra and these were assigned to 1:1 contact ion pair, ...

  6. Order-disorder phase transformations in quaternary pyrochlore oxide system: Investigated by X-ray diffraction, transmission electron microscopy and Raman spectroscopic techniques

    International Nuclear Information System (INIS)

    Radhakrishnan, A.N.; Prabhakar Rao, P.; Sibi, K.S.; Deepa, M.; Koshy, Peter

    2009-01-01

    Order-disorder transformations in a quaternary pyrochlore oxide system, Ca-Y-Zr-Ta-O, were studied by powder X-ray diffraction (XRD) method, transmission electron microscope (TEM) and FT-NIR Raman spectroscopic techniques. The solid solutions in different ratios, 4:1, 2:1, 1:1, 1:2, 1:4, 1:6, of CaTaO 3.5 and YZrO 3.5 were prepared by the conventional high temperature ceramic route. The XRD results and Rietveld analysis revealed that the crystal structure changed from an ordered pyrochlore structure to a disordered defect fluorite structure as the ratios of the solid solutions of CaTaO 3.5 and YZrO 3.5 were changed from 4:1 to 1:4. This structural transformation in the present system is attributed to the lowering of the average cation radius ratio, r A /r B as a result of progressive and simultaneous substitution of larger cation Ca 2+ for Y 3+ at A sites and smaller cation Ta 5+ for Zr 4+ at B sites. Raman spectroscopy and TEM analysis corroborated the XRD results. - Graphical abstract: Selected area electron diffraction (SAED) patterns showed highly ordered diffraction maxima with characteristic superlattice weak diffraction spots of the pyrochlore structure for (a) Ca 0.6 7Y 1.33 Zr 1.33 Ta 0.33 O 7 (C2YZT2) and bright diffraction maxima arranged in a ring pattern of the fluorite structure for (b) Ca 0.29 7Y 1.71 Zr 1.71 Ta 0.29 O 7 (CY6Z6T).

  7. Raman and infrared spectroscopic investigations of a ferroelastic phase transition in B a2ZnTe O6 double perovskite

    Science.gov (United States)

    Moreira, Roberto L.; Lobo, Ricardo P. S. M.; Ramos, Sérgio L. L. M.; Sebastian, Mailadil T.; Matinaga, Franklin M.; Righi, Ariete; Dias, Anderson

    2018-05-01

    The low-temperature vibrational properties of B a2ZnTe O6 double-perovskite ceramics obtained by the solid-state route were investigated by Raman scattering and Fourier-transform infrared reflectivity. We found that this material undergoes a reversible ferroelastic phase transition at around 140 K, well compatible with a recently proposed rhombohedral-to-monoclinic structural change that would occur below 165 K. Complementary calorimetric measurements showed that the phase transition has a first-order character, with an entropy jump compatible with a displacive mechanism. The vibrational spectra show clearly the splitting of the doubly degenerate E modes into nondegenerate representations of the low-symmetry phase. In particular, the lowest-frequency Raman mode presents soft-mode behavior and splits below the critical temperature, confirming the in-plane ferroelastic deformation in the low-temperature phase.

  8. Raman spectroscopic study of reaction dynamics

    Science.gov (United States)

    MacPhail, R. A.

    1990-12-01

    The Raman spectra of reacting molecules in liquids can yield information about various aspects of the reaction dynamics. The author discusses the analysis of Raman spectra for three prototypical unimolecular reactions, the rotational isomerization of n-butane and 1,2-difluoroethane, and the barrierless exchange of axial and equatorial hydrogens in cyclopentane via pseudorotation. In the first two cases the spectra are sensitive to torsional oscillations of the gauche conformer, and yield estimates of the torsional solvent friction. In the case of cyclopentane, the spectra can be used to discriminate between different stochastic models of the pseudorotation dynamics, and to determine the relevant friction coefficients.

  9. A micro-Raman spectroscopic investigation of leukemic U-937 cells treated with Crotalaria agatiflora Schweinf and the isolated compound madurensine

    Science.gov (United States)

    le Roux, Karlien; Prinsloo, Linda C.; Hussein, Ahmed A.; Lall, Namrita

    In South Africa traditional medicine plays an important role in primary health care and therefore it is very important that the medicinal use of plants is scientifically tested for toxicity and effectiveness. It was established that the ethanolic extract of the leaves of Crotalaria agatiflora, as well as the isolated compound madurensine, is moderately toxic against leukemic U-937 cells. Light microscopic investigations indicated that symptoms of cell death are induced during treatments, but flow cytometry analysis of treated cells, using annexin-V and propidium iodide, showed that apoptosis and necrosis are insignificantly induced. The Raman results suggested that protein extraction and DNA melting occur in the cells during treatment with the ethanolic extracts (IC50 value 73.9 μg/mL), drastically changing the molecular content of the cells. In contrast, treatment with madurensine (IC50 value 136.5 μg/mL), an isolated pyrrolizidine alkaloid from the ethanolic extract of the leaves, did not have the same effect. The results are also compared to that of cells treated with actinomycin D, a compound known to induce apoptosis. The investigation showed that micro-Raman spectroscopy has great promise to be used for initial screening of samples to determine the effects of different treatments on cancerous cell lines together with conventional methods. The results highlight the fact that for many natural products used for medicinal purposes, the therapeutic effect of the crude plant extract tends to be significantly more effective than the particular action of its individual constituents.

  10. Oral cancer screening: serum Raman spectroscopic approach

    Science.gov (United States)

    Sahu, Aditi K.; Dhoot, Suyash; Singh, Amandeep; Sawant, Sharada S.; Nandakumar, Nikhila; Talathi-Desai, Sneha; Garud, Mandavi; Pagare, Sandeep; Srivastava, Sanjeeva; Nair, Sudhir; Chaturvedi, Pankaj; Murali Krishna, C.

    2015-11-01

    Serum Raman spectroscopy (RS) has previously shown potential in oral cancer diagnosis and recurrence prediction. To evaluate the potential of serum RS in oral cancer screening, premalignant and cancer-specific detection was explored in the present study using 328 subjects belonging to healthy controls, premalignant, disease controls, and oral cancer groups. Spectra were acquired using a Raman microprobe. Spectral findings suggest changes in amino acids, lipids, protein, DNA, and β-carotene across the groups. A patient-wise approach was employed for data analysis using principal component linear discriminant analysis. In the first step, the classification among premalignant, disease control (nonoral cancer), oral cancer, and normal samples was evaluated in binary classification models. Thereafter, two screening-friendly classification approaches were explored to further evaluate the clinical utility of serum RS: a single four-group model and normal versus abnormal followed by determining the type of abnormality model. Results demonstrate the feasibility of premalignant and specific cancer detection. The normal versus abnormal model yields better sensitivity and specificity rates of 64 and 80% these rates are comparable to standard screening approaches. Prospectively, as the current screening procedure of visual inspection is useful mainly for high-risk populations, serum RS may serve as a useful adjunct for early and specific detection of oral precancers and cancer.

  11. Surface enhanced Raman scattering spectroscopic waveguide

    Science.gov (United States)

    Lascola, Robert J; McWhorter, Christopher S; Murph, Simona H

    2015-04-14

    A waveguide for use with surface-enhanced Raman spectroscopy is provided that includes a base structure with an inner surface that defines a cavity and that has an axis. Multiple molecules of an analyte are capable of being located within the cavity at the same time. A base layer is located on the inner surface of the base structure. The base layer extends in an axial direction along an axial length of an excitation section. Nanoparticles are carried by the base layer and may be uniformly distributed along the entire axial length of the excitation section. A flow cell for introducing analyte and excitation light into the waveguide and a method of applying nanoparticles may also be provided.

  12. Raman spectroscopic signature of vaginal fluid and its potential application in forensic body fluid identification.

    Science.gov (United States)

    Sikirzhytskaya, Aliaksandra; Sikirzhytski, Vitali; Lednev, Igor K

    2012-03-10

    Traces of human body fluids, such as blood, saliva, sweat, semen and vaginal fluid, play an increasingly important role in forensic investigations. However, a nondestructive, easy and rapid identification of body fluid traces at the scene of a crime has not yet been developed. The obstacles have recently been addressed in our studies, which demonstrated the considerable potential of Raman spectroscopy. In this study, we continued to build a full library of body fluid spectroscopic signatures. The problems concerning vaginal fluid stain identification were addressed using Raman spectroscopy coupled with advanced statistical analysis. Calculated characteristic Raman and fluorescent spectral components were used to build a multidimensional spectroscopic signature of vaginal fluid, which demonstrated good specificity and was able to handle heterogeneous samples from different donors. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  13. Electronic [UV-Visible] and vibrational [FT-IR, FT-Raman] investigation and NMR-mass spectroscopic analysis of terephthalic acid using quantum Gaussian calculations

    Science.gov (United States)

    Karthikeyan, N.; Joseph Prince, J.; Ramalingam, S.; Periandy, S.

    2015-03-01

    In this research work, the vibrational IR, polarization Raman, NMR and mass spectra of terephthalic acid (TA) were recorded. The observed fundamental peaks (IR, Raman) were assigned according to their distinctiveness region. The hybrid computational calculations were carried out for calculating geometrical and vibrational parameters by DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results were tabulated. The molecular mass spectral data related to base molecule and substitutional group of the compound was analyzed. The modification of the chemical property by the reaction mechanism of the injection of dicarboxylic group in the base molecule was investigated. The 13C and 1H NMR spectra were simulated by using the gauge independent atomic orbital (GIAO) method and the absolute chemical shifts related to TMS were compared with experimental spectra. The study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, were performed by hybrid Gaussian calculation methods. The orbital energies of different levels of HOMO and LUMO were calculated and the molecular orbital lobe overlapping showed the inter charge transformation between the base molecule and ligand group. From the frontier molecular orbitals (FMO), the possibility of electrophilic and nucleophilic hit also analyzed. The NLO activity of the title compound related to Polarizability and hyperpolarizability were also discussed. The present molecule was fragmented with respect to atomic mass and the mass variation depends on the substitutions have also been studied.

  14. Electronic [UV-Visible] and vibrational [FT-IR, FT-Raman] investigation and NMR-mass spectroscopic analysis of terephthalic acid using quantum Gaussian calculations.

    Science.gov (United States)

    Karthikeyan, N; Prince, J Joseph; Ramalingam, S; Periandy, S

    2015-03-15

    In this research work, the vibrational IR, polarization Raman, NMR and mass spectra of terephthalic acid (TA) were recorded. The observed fundamental peaks (IR, Raman) were assigned according to their distinctiveness region. The hybrid computational calculations were carried out for calculating geometrical and vibrational parameters by DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results were tabulated. The molecular mass spectral data related to base molecule and substitutional group of the compound was analyzed. The modification of the chemical property by the reaction mechanism of the injection of dicarboxylic group in the base molecule was investigated. The (13)C and (1)H NMR spectra were simulated by using the gauge independent atomic orbital (GIAO) method and the absolute chemical shifts related to TMS were compared with experimental spectra. The study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, were performed by hybrid Gaussian calculation methods. The orbital energies of different levels of HOMO and LUMO were calculated and the molecular orbital lobe overlapping showed the inter charge transformation between the base molecule and ligand group. From the frontier molecular orbitals (FMO), the possibility of electrophilic and nucleophilic hit also analyzed. The NLO activity of the title compound related to Polarizability and hyperpolarizability were also discussed. The present molecule was fragmented with respect to atomic mass and the mass variation depends on the substitutions have also been studied. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  15. Raman spectroscopic characterization of multiwall carbon nanotubes and of composites

    Directory of Open Access Journals (Sweden)

    L. Bokobza

    2012-07-01

    Full Text Available In this work Raman spectroscopy was used for extensive characterization of multiwall carbon nanotube (MWNTs and of MWCNTs/rubber composites. We have measured the Raman spectra of bundled and dispersed multiwall carbon nanotubes. All the Raman bands of the carbon nanotubes are seen to shift to higher wavenumbers upon debundling on account of less intertube interactions. Effects of laser irradiation were also investigated. Strong effects are observed by changing the wavelength of the laser excitation. On the other hand, at a given excitation wavelength, changes on the Raman bands are observed by changing the laser power density due to sample heating during the measurement procedure.

  16. Raman spectroscopic analysis of real samples: Brazilian bauxite mineralogy

    Science.gov (United States)

    Faulstich, Fabiano Richard Leite; Castro, Harlem V.; de Oliveira, Luiz Fernando Cappa; Neumann, Reiner

    2011-10-01

    In this investigation, Raman spectroscopy with 1064 and 632.8 nm excitation was used to investigate real mineral samples of bauxite ore from mines of Northern Brazil, together with Raman mapping and X-rays diffraction. The obtained results show clearly that the use of microRaman spectroscopy is a powerful tool for the identification of all the minerals usually found in bauxites: gibbsite, kaolinite, goethite, hematite, anatase and quartz. Bulk samples can also be analysed, and FT-Raman is more adequate due to better signal-to-noise ratio and representativity, although not efficient for kaolinite. The identification of fingerprinting vibrations for all the minerals allows the acquisition of Raman-based chemical maps, potentially powerful tools for process mineralogy applied to bauxite ores.

  17. Spectroscopic investigations (FT-IR & FT-Raman) and molecular docking analysis of 6-[1-methyl-4-nitro-1H-imidazol-5-yl) sulfonyl]-7H-purine

    Science.gov (United States)

    Prasath, M.; Govindammal, M.; Sathya, B.

    2017-10-01

    The Azathioprine is used as anticancer agent. Azathioprine is chemically called 6-[1-methyl-4-nitro-1H-imidazol-5-yl) sulfonyl]-7H-purine (6M4N5P). The vibrational analysis of the 6M4N5P compound was carried out by using FT-IR and FT-Raman spectroscopic techniques and compared with aspects. The optimized geometry, frequency and intensity of the vibrational bands of 6M4N5P were obtained from the HF and DFT methods with 6-31G (d,p) basis set. The harmonic vibrational frequencies were calculated and the scaled values have been compared with experimental FT-IR and FT-Raman spectra. The calculated Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) energies show that charge transfer occur within the molecule. MEP (Molecular Electrostatic Potential) is very useful in the investigation of the charge distributions and molecular structure. The molecule orbital contributions were determined by using the total density of states (TDOS). A molecular docking analysis has been carried out to understand the conformational change and electrostatic properties of 6M4N5P in the active site of Rac1-Receptor.

  18. Raman spectroscopic study of "The Malatesta": a Renaissance painting?

    Science.gov (United States)

    Edwards, Howell G M; Vandenabeele, Peter; Benoy, Timothy J

    2015-02-25

    Raman spectroscopic analysis of the pigments on an Italian painting described as a "Full Length Portrait of a Gentleman", known also as the "Malatesta", and attributed to the Renaissance period has established that these are consistent with the historical research provenance undertaken earlier. Evidence is found for the early 19th Century addition of chrome yellow to highlighted yellow ochre areas in comparison with a similar painting executed in 1801 by Sir Thomas Lawrence of John Kemble in the role of Hamlet, Prince of Denmark. The Raman data are novel in that no analytical studies have previously been made on this painting and reinforces the procedure whereby scientific analyses are accompanied by parallel historical research. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Raman spectroscopic analysis of a `noli me tangere' painting

    Science.gov (United States)

    Hibberts, Stephen; Edwards, Howell G. M.; Abdel-Ghani, Mona; Vandenabeele, Peter

    2016-12-01

    The discovery of an oil painting in seriously damaged condition with an important historical and a heterodox detail with possible origins in the late fifteenth century has afforded the opportunity for Raman microscopic analysis prior to its restoration being undertaken. The painting depicts a risen Christ following His crucifixion in a `noli me tangere' pose with three women in an Italian terrace garden with a stone balustrade overlooking a rural landscape and an undoubted view of late-medieval Florence. The picture has suffered much abuse and is in very poor condition, which is possibly attributable to its controversial portrayal of a polydactylic Christ with six toes on His right foot. By the late sixteenth century, after the Council of Trent, this portrayal would almost certainly have been frowned upon by the Church authorities or more controversially as a depiction of the holy. Raman spectroscopic analysis of the pigments places the painting as being consistent chronologically with the Renaissance period following the identification of cinnabar, haematite, red lead, lead white, goethite, verdigris, caput mortuum and azurite with no evidence of more modern synthetic pigments or of modern restoration having been carried out. An interesting pigment mixture found here is that of the organic dye carmine and cinnabar to produce a particular bright red pigment coloration. Stratigraphic examination of the paint fragments has demonstrated the presence of an orange resin layer immediately on top of the canvas substrate, effectively rendering the pigment as a sandwich between this substratal resin and the overlying varnish. The Raman spectroscopic evidence clearly indicates that an attribution of the artwork to the Renaissance is consistent with the scientific analysis of the pigment composition. This article is part of the themed issue "Raman spectroscopy in art and archaeology".

  20. Raman spectroscopic analysis of a 'noli me tangere' painting.

    Science.gov (United States)

    Hibberts, Stephen; Edwards, Howell G M; Abdel-Ghani, Mona; Vandenabeele, Peter

    2016-12-13

    The discovery of an oil painting in seriously damaged condition with an important historical and a heterodox detail with possible origins in the late fifteenth century has afforded the opportunity for Raman microscopic analysis prior to its restoration being undertaken. The painting depicts a risen Christ following His crucifixion in a 'noli me tangere' pose with three women in an Italian terrace garden with a stone balustrade overlooking a rural landscape and an undoubted view of late-medieval Florence. The picture has suffered much abuse and is in very poor condition, which is possibly attributable to its controversial portrayal of a polydactylic Christ with six toes on His right foot. By the late sixteenth century, after the Council of Trent, this portrayal would almost certainly have been frowned upon by the Church authorities or more controversially as a depiction of the holy. Raman spectroscopic analysis of the pigments places the painting as being consistent chronologically with the Renaissance period following the identification of cinnabar, haematite, red lead, lead white, goethite, verdigris, caput mortuum and azurite with no evidence of more modern synthetic pigments or of modern restoration having been carried out. An interesting pigment mixture found here is that of the organic dye carmine and cinnabar to produce a particular bright red pigment coloration. Stratigraphic examination of the paint fragments has demonstrated the presence of an orange resin layer immediately on top of the canvas substrate, effectively rendering the pigment as a sandwich between this substratal resin and the overlying varnish. The Raman spectroscopic evidence clearly indicates that an attribution of the artwork to the Renaissance is consistent with the scientific analysis of the pigment composition.This article is part of the themed issue 'Raman spectroscopy in art and archaeology'. © 2016 The Author(s).

  1. Primidone--an antiepileptic drug--characterisation by quantum chemical and spectroscopic (FTIR, FT-Raman, 1H, 13C NMR and UV-Visible) investigations.

    Science.gov (United States)

    Arjunan, V; Santhanam, R; Subramanian, S; Mohan, S

    2013-05-15

    The solid phase FTIR and FT-Raman spectra of primidone were recorded in the regions 4000-400 cm(-1) and 4000-100 cm(-1), respectively. The vibrational spectra were analysed and the observed fundamentals were assigned and analysed. The experimental wavenumbers were compared with the theoretical scaled vibrational wavenumbers determined by DFT methods. The Raman intensities were also determined with B3LYP/6-31G(d,p) method. The total electron density and molecular electrostatic potential surface of the molecule were constructed by using B3LYP/6-311++G(d,p) method to display electrostatic potential (electron+nuclei) distribution. The HOMO and LUMO energies were measured. Natural bond orbital analysis of primidone has been performed to indicate the presence of intramolecular charge transfer. The (1)H and (13)C NMR spectra were recorded and the chemical shifts of the molecule were calculated. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Spectroscopic Analysis of Neurotransmitters: A Theoretical and Experimental Raman Study

    Science.gov (United States)

    Alonzo, Matthew

    Surface-enhanced Raman spectroscopy (SERS) was applied to investigate the feasibility in the detection and monitoring of the dopamine (DA) neurotransmitter adsorbed onto silver nanoparticles (Ag NPs) at 10-11 molar, a concentration far below physiological levels. In addition, density functional theory (DFT) calculations were obtained with the Gaussian-09 analytical suite software to generate the theoretical molecular configuration of DA in its neutral, cationic, anionic, and dopaminequinone states for the conversion of computer-simulated Raman spectra. Comparison of theoretical and experimental results show good agreement and imply the presence of dopamine in all of its molecular forms in the experimental setting. The dominant dopamine Raman bands at 750 cm-1 and 795 cm-1 suggest the adsorption of dopaminequinone onto the silver nanoparticle surface. The results of this experiment give good insight into the applicability of using Raman spectroscopy for the biodetection of neurotransmitters.

  3. ATR-FTIR and Raman spectroscopic investigation of the electroporation-mediated transdermal delivery of a nanocarrier system containing an antitumour drug.

    Science.gov (United States)

    Balázs, Boglárka; Sipos, Péter; Danciu, Corina; Avram, Stefana; Soica, Codruta; Dehelean, Cristina; Varju, Gábor; Erős, Gábor; Budai-Szűcs, Mária; Berkó, Szilvia; Csányi, Erzsébet

    2016-01-01

    The aim of the present work was the optimization of the transdermal delivery of a lyotropic liquid crystal genistein-based formulation (LLC-GEN). LLC was chosen as medium in view of the poor solubility of GEN in water. Membrane diffusion and penetration studies were carried out with a Franz diffusion cell, through a synthetic membrane in vitro, a chick chorioallantoic membrane ex ovo, and ex vivo excised human epidermis. Thereafter, LLC-GEN was combined with electroporation (EP) to enhance the transdermal drug delivery. The synergistic effect of EP was verified by in vivo ATR-FTIR and ex vivo Raman spectroscopy on hairless mouse skin.

  4. Experimental Raman and infrared investigation of phenobarbital febarabamate, difebarbamate and tetrabamate

    Science.gov (United States)

    Buchet, R.; Bill, H.; Siegfried, B.

    The results of a Raman and an i.r. investigation show that the tetrabamate molecule is formed by the hydrogen bonded constituants phenobarbital, febarbamate. Detailed spectroscopic results are given on these four molecules.

  5. Comprehensive quantum chemical and spectroscopic (FTIR, FT-Raman, 1H, 13C NMR) investigations of O-desmethyltramadol hydrochloride an active metabolite in tramadol - An analgesic drug

    Science.gov (United States)

    Arjunan, V.; Santhanam, R.; Marchewka, M. K.; Mohan, S.

    2014-03-01

    O-desmethyltramadol is one of the main metabolites of tramadol widely used clinically and has analgesic activity. The FTIR and FT-Raman spectra of O-desmethyl tramadol hydrochloride are recorded in the solid phase in the regions 4000-400 cm-1 and 4000-100 cm-1, respectively. The observed fundamentals are assigned to different normal modes of vibration. Theoretical studies have been performed as its hydrochloride salt. The structure of the compound has been optimised with B3LYP method using 6-31G** and cc-pVDZ basis sets. The optimised bond length and bond angles are correlated with the X-ray data. The experimental wavenumbers were compared with the scaled vibrational frequencies determined by DFT methods. The IR and Raman intensities are determined with B3LYP method using cc-pVDZ and 6-31G(d,p) basic sets. The total electron density and molecular electrostatic potential surfaces of the molecule are constructed by using B3LYP/cc-pVDZ method to display electrostatic potential (electron + nuclei) distribution. The electronic properties HOMO and LUMO energies were measured. Natural bond orbital analysis of O-desmethyltramadol hydrochloride has been performed to indicate the presence of intramolecular charge transfer. The 1H and 13C NMR chemical shifts of the molecule have been anlysed.

  6. Raman spectroscopic studies of optically trapped red blood cells

    International Nuclear Information System (INIS)

    Dasgupta, R.; Gupta, P.K.

    2010-01-01

    Raman spectroscopic studies were performed on optically trapped red blood cells (RBCs) collected from healthy volunteers and patients suffering from malaria (Plasmodium vivax infection) using near infrared (785 nm) laser source. The results show significant alteration in the spectra averaged over ∼ 50 non-parasitized RBCs per sample. As compared to RBCs from healthy donors, in cells collected from malaria patients, a significant decrease in the intensity of the low spin (oxygenated-haemoglobin) marker Raman band at 1223 cm -1 (υ 13 or υ 42 ) along with a concomitant increase in the high spin (deoxygenated-haemoglobin) marker bands at 1210 cm -1 (υ 5 + υ 18 ) and 1546 cm -1 (υ 11 ) was observed. The changes primarily suggest a reduced haemoglobin-oxygen affinity for the non-parasitized red cells in malaria patients. The possible causes include up regulation of intra-erythrocytic 2,3-diphosphoglycerate and/or ineffective erythropoiesis resulted from the disease. During the above study we also observed that significant photo-damage may results to the intracellular haemoglobin (Hb) if higher laser power is used. For a laser power above ∼ 5 mW the observed increase in intensity of the Raman bands at 975 cm -1 (υ 46 ), 1244 cm -1 (υ 42 ) and 1366 cm -1 (υ 4 ) with increasing exposure time suggests photo-denaturation of Hb and the concomitant decrease in intensity of the Raman band at 1544 cm -1 (υ 11 ) suggests photo induced methaemoglobin formation. The photo damage of intracellular haemoglobin by the above processes was also observed to result in intracellular heme aggregation. (author)

  7. Raman spectroscopic characterisations and analytical discrimination between caffeine and demethylated analogues of pharmaceutical relevance

    Science.gov (United States)

    Edwards, H. G. M.; Munshi, T.; Anstis, M.

    2005-05-01

    The FT Raman spectrum of caffeine was analysed along with that of its demethylated analogues, theobromine and theophylline. The similar but not identical structures of these three compounds allowed a more detailed assignment of the Raman bands. Noticeable differences in the Raman spectra of these compounds were apparent and key marker bands have been identified for the spectroscopic identification of these three compounds.

  8. Spectroscopic investigation (FT-IR, FT-Raman), HOMO-LUMO, NBO, and molecular docking analysis of N-ethyl-N-nitrosourea, a potential anticancer agent

    Science.gov (United States)

    Singh, Priyanka; Islam, S. S.; Ahmad, Hilal; Prabaharan, A.

    2018-02-01

    Nitrosourea plays an important role in the treatment of cancer. N-ethyl-N-nitrosourea, also known as ENU, (chemical formula C3H7N3O2), is a highly potent mutagen. The chemical is an alkylating agent and acts by transferring the ethyl group of ENU to nucleobases (usually thymine) in nucleic acids. The molecular structure of N-ethyl-N-nitrosourea has been elucidated using experimental (FT-IR and FT-Raman) and theoretical (DFT) techniques. APT charges, Mulliken atomic charges, Natural bond orbital, Electrostatic potential, HOMO-LUMO and AIM analysis were performed to identify the reactive sites and charge transfer interactions. Furthermore, to evaluate the anticancer activity of ENU molecular docking studies were carried out against 2JIU protein.

  9. Raman spectroscopic study of the oxidation state of Eu in molten LiCl-KCl

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seung; Yun, Jong-Il [KAIST, Daejeon(Korea, Republic of)

    2016-10-15

    Spectroscopy can provide high reliability for the quantitative analysis of such system. The molar absorptivity of Eu(II) at 325 nm is reported as about 1645 M{sup -1}cm{sup -1}, which is too high to apply to higher concentration. A high-temperature Raman spectroscopy has been set and employed for analyzing the molecular structure and coordination complex and investigating the oxidation state of europium in molten LiCl-KCl. Europium can be present in divalent state while many other lanthanides exist in trivalent state. The thermodynamic properties of europium ions have been studied using electrochemical methods, spectroscopic methods, and EPR technique. Although there has been discrepancy of the reduced amount of europium in previous works, the majority of Eu(III) is thought to be reduced to Eu(II) in molten LiCl-KCl spontaneously at relatively low concentration (< 7.5 × 10{sup -4} M). Raman spectroscopy was employed to investigate the oxidation state of EuClx in LiCl-KCl at 500 .deg. C. The Raman scattering results suggest the majority of trivalent europium is reduced to divalent state with the composition change by vaporization. The Raman bands show highly asymmetric structure, quite different from regular octahedral structure.

  10. Raman Spectroscopic Study on Decorative Glasses in Thailand

    International Nuclear Information System (INIS)

    Won-In, K.; Ponkrapan, S.; Dararutana, P.

    2011-01-01

    Glasses have been used as decorative objects in Thailand for several hundred years. Decorative glasses can generally be seen as architectural components in old styled palaces and Buddhist objects. There were various colors ranging from transparent to amber, blue, green and red with different shades among glass of different colors. Fragments of archaeological glass samples were characterized for the first time using Raman microscopy with the aim of obtaining information that would lead to identification of the glass samples by means of laser scattering. The samples were also investigated using other techniques, such as particle induced X-ray emission spectroscopy and scanning electron microscope operated with energy dispersive X-ray fluorescence spectrometer. They were mostly lead-silica based glasses. The colors resulted from metal ions. The difference in chemical composition was confirmed by Raman signature spectra. (author)

  11. Multidimensional Raman spectroscopic signatures as a tool for forensic identification of body fluid traces: a review.

    Science.gov (United States)

    Sikirzhytski, Vitali; Sikirzhytskaya, Aliaksandra; Lednev, Igor K

    2011-11-01

    The analysis of body fluid traces during forensic investigations is a critical step in determining the key details of a crime. Several confirmatory and presumptive biochemical tests are currently utilized. However, these tests are all destructive, and no single method can be used to analyze all body fluids. This review outlines recent progress in the development of a novel universal approach for the nondestructive, confirmatory identification of body fluid traces using Raman spectroscopy. The method is based on the use of multidimensional spectroscopic signatures of body fluids and accounts for the intrinsic heterogeneity of dry traces and donor variation. The results presented here demonstrate that Raman spectroscopy has potential for identifying traces of semen, blood, saliva, sweat, and vaginal fluid with high confidence.

  12. Raman spectroscopic study of uranyl complex in alkali chloride melts

    International Nuclear Information System (INIS)

    Fujii, Toshiyuki; Uda, Takeshi; Iwadate, Yasuhiko; Nagai, Takayuki; Uehara, Akihiro; Yamana, Hajimu

    2013-01-01

    Raman spectra of alkali chloride melts containing 3 mol% U(VI) were measured at 823 K. The complexation of UO 2 Cl 4 2- in binary mixtures of LiCl-KCl, LiCl-RbCl, and LiCl-CsCl was investigated. The spectrum of UO 2 Cl 4 2- obtained was characterized by Raman active vibration modes, that is, totally symmetric stretching vibrations A 1g (ν 1 : OUO) and A 1g (ν 2 : UCl 4 ), and bending vibration E g (ν 8: UO 2 Cl 2 ). The dependence of polarizing power of solvent cations on the vibrational frequencies was clarified. The ν 8 frequencies were insensitive to the change in the polarizing power. On the other hand, the ν 1 and ν 2 frequencies increased with the rise of polarizing power. The Raman shifts suggest that the square bipyramidal structure of UO 2 Cl 4 2- is kept in various binary alkali chlorides, while O 2− and Cl − around U(VI) are clearly polarized by the increase of polarizing power

  13. HPLC assisted Raman spectroscopic studies on bladder cancer

    Science.gov (United States)

    Zha, W. L.; Cheng, Y.; Yu, W.; Zhang, X. B.; Shen, A. G.; Hu, J. M.

    2015-04-01

    We applied confocal Raman spectroscopy to investigate 12 normal bladder tissues and 30 tumor tissues, and then depicted the spectral differences between the normal and the tumor tissues and the potential canceration mechanism with the aid of the high-performance liquid chromatographic (HPLC) technique. Normal tissues were demonstrated to contain higher tryptophan, cholesterol and lipid content, while bladder tumor tissues were rich in nucleic acids, collagen and carotenoids. In particular, β-carotene, one of the major types of carotenoids, was found through HPLC analysis of the extract of bladder tissues. The statistical software SPSS was applied to classify the spectra of the two types of tissues according to their differences. The sensitivity and specificity of 96.7 and 66.7% were obtained, respectively. In addition, different layers of the bladder wall including mucosa (lumps), muscle and adipose bladder tissue were analyzed by Raman mapping technique in response to previous Raman studies of bladder tissues. All of these will play an important role as a directive tool for the future diagnosis of bladder cancer in vivo.

  14. Mid-infrared spectroscopic investigation

    International Nuclear Information System (INIS)

    Walter, L.; Vergo, N.; Salisbury, J.W.

    1987-01-01

    Mid-infrared spectroscopic research efforts are discussed. The development of a new instrumentation to permit advanced measurements in the mid-infrared region of the spectrum, the development of a special library of well-characterized mineral and rock specimens for interpretation of remote sensing data, and cooperative measurements of the spectral signatures of analogues of materials that may be present on the surfaces of asteroids, planets or their Moons are discussed

  15. Multidimensional Raman spectroscopic signature of sweat and its potential application to forensic body fluid identification.

    Science.gov (United States)

    Sikirzhytski, Vitali; Sikirzhytskaya, Aliaksandra; Lednev, Igor K

    2012-03-09

    This proof-of-concept study demonstrated the potential of Raman microspectroscopy for nondestructive identification of traces of sweat for forensic purposes. Advanced statistical analysis of Raman spectra revealed that dry sweat was intrinsically heterogeneous, and its biochemical composition varies significantly with the donor. As a result, no single Raman spectrum could adequately represent sweat traces. Instead, a multidimensional spectroscopic signature of sweat was built that allowed for the presentation of any single experimental spectrum as a linear combination of two fluorescent backgrounds and three Raman spectral components dominated by the contribution from lactate, lactic acid, urea and single amino acids. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Determination of drug content in semisolid formulations by non-invasive spectroscopic methods: FTIR - ATR, - PAS, - Raman and PDS

    International Nuclear Information System (INIS)

    Gotter, B; Hein, J; Neubert, R H H; Faubel, W; Heissler, St

    2010-01-01

    This study elucidates the potential use of photothermal deflection spectroscopy (PDS), FTIR photoacoustic (FTIR-PAS), FT Raman, and FTIR-attenuated total reflection (FTIR-ATR) spectroscopy as analytical tools for investigating the drug content in semisolid formulations. Regarding the analytical parameters, this study demonstrates the photothermal beam deflection to be definitely comparable to well established spectroscopic methods for this purpose. The correlation coefficients range from 0.990 to 0.999. Likewise, repeatability and limit of detection are comparable.

  17. Fourier Transform Infrared and Resonance Raman Spectroscopic Studies of Bacteriorhodopsin.

    Science.gov (United States)

    Earnest, Thomas Nixon

    Fourier transform infrared and resonance Raman spectroscopy were used to investigate the structure and function of the light-activated, transmembrane proton pump, bacteriorhodopsin, from the purple membrane of Halobacterium halobium. Bacteriorhodopsin (bR) is a 27,000 dalton integral membrane protein consisting of 248 amino acids with a retinylidene chromophore. Absorption of a photon leads to the translocation of one or two protons from the inside of the cell to the outside. Resonance Raman spectroscopy allows for the study of the configuration of retinal in bR and its photointermediates by the selective enhancement of vibrational modes of the chromophore. This technique was used to determine that the chromophore is attached to lysine-216 in both the bR _{570} and the M _{412} intermediates. In bR with tyrosine-64 selectively nitrated or aminated, the chromophore appears to have the same configuration in that bR _{570} (all- trans) and M _{412} (13- cis) states as it does in unmodified bR. Polarized Fourier transform infrared spectroscopy (FTIR) permits the study of the direction of transition dipole moments arising from molecular vibrations of the protein and the retinal chromophore. The orientation of alpha helical and beta sheet components was determined for bR with the average helical tilt found to lie mostly parallel to the membrane normal. The beta sheet structures also exhibit an IR linear dichroism for the amide I and amide II bands which suggest that the peptide backbone is mostly perpendicular to the membrane plane although it is difficult to determine whether the bands originate from sheet or turn components. The orientation of secondary structure components of the C-1 (residues 72-248) and C-2 (residues 1-71) fragments were also investigated to determine the structure of these putative membrane protein folding intermediates. Polarized, low temperature FTIR -difference spectroscopy was then used to investigate the structure of bR as it undergoes

  18. The pH dependent Raman spectroscopic study of caffeine

    Science.gov (United States)

    Kang, Jian; Gu, Huaimin; Zhong, Liang; Hu, Yongjun; Liu, Fang

    2011-02-01

    First of all the surface enhanced Raman spectroscopy (SERS) and normal Raman spectra of caffeine aqueous solution were obtained at different pH values. In order to obtain the detailed vibrational assignments of the Raman spectroscopy, the geometry of caffeine molecule was optimized by density functional theory (DFT) calculation. By comparing the SERS of caffeine with its normal spectra at different pH values; it is concluded that pH value can dramatically affect the SERS of caffeine, but barely affect the normal Raman spectrum of caffeine aqueous solution. It can essentially affect the reorientation of caffeine molecule to the Ag colloid surface, but cannot impact the vibration of functional groups and chemical bonds in caffeine molecule.

  19. Infrared absorption and Raman scattering spectroscopic studies of condensed ions

    International Nuclear Information System (INIS)

    Dao, N.Q.; Knidiri, M.

    1975-01-01

    Infrared and Raman spectra of the complex K 5 (UO 2 ) 2 F 9 were recorded in the region 4000 to 80 cm -1 . Factor group analysis was used to classify the internal vibrations of the binuclear ion (UO 2 ) 2 F 9 5- . Infrared and Raman spectra were assigned and splitting of the internal modes of the (UO 2 ) 2 F 9 5- anion interpreted. (author)

  20. Raman Spectroscopic Studies of YBa2Cu3O7 Coated Conductors

    International Nuclear Information System (INIS)

    Choi, Mi Kyeung; Mnh, Nguyen Van; Bae, J. S.; Jo, William; Yang, In Sang; Ko, Rock Kil; Ha, Hong Soo; Park, Chan

    2005-01-01

    We present results of Raman spectroscopic studies of superconducting YBa 2 Cu 3 O 7 (YBCO) coated conductors. Raman scattering is used to characterize optical phonon modes, oxygen content, c-axis misalignment, and second phases of the YBCO coated conductors at a micro scale. A two-dimensional mapping of Raman spectra with transport properties has been performed to elucidate the effect of local propertied on current path and superconducting phase. The information taken from the local measurement will be useful for optimizing the process condition.

  1. Raman spectroscopic study of plasma-treated salmon DNA

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Geon Joon; Kim, Yong Hee; Choi, Eun Ha [Plasma Bioscience Research Center, Kwangwoon University, Seoul 139-701 (Korea, Republic of); Kwon, Young-Wan [Department of Chemistry, Korea University, Seoul 136-701 (Korea, Republic of)

    2013-01-14

    In this research, we studied the effect of plasma treatment on the optical/structural properties of the deoxyribonucleic acid (DNA) extracted from salmon sperm. DNA-cetyltrimethylammonium (CTMA) films were obtained by complexation of DNA with CTMA. Circular dichroism (CD) and Raman spectra indicated that DNA retained its double helical structure in the solid film. The Raman spectra exhibited several vibration modes corresponding to the nuclear bases and the deoxyribose-phosphate backbones of the DNA, as well as the alkylchains of CTMA. Dielectric-barrier-discharge (DBD) plasma treatment induced structural modification and damage to the DNA, as observed by changes in the ultraviolet-visible absorption, CD, and Raman spectra. The optical emission spectra of the DBD plasma confirmed that DNA modification was induced by plasma ions such as reactive oxygen species and reactive nitrogen species.

  2. Spectroscopic investigations of neodymium cyclotriphosphates

    Energy Technology Data Exchange (ETDEWEB)

    Jouini, A.; Gacon, J.C.; Brenier, A.; Ferid, M.; Trabelsi-Ayadi, M

    2002-11-15

    In the framework of systematic investigations in the properties of rare-earth cyclotriphosphates, polycristalline samples of La{sub 1-x}Nd{sub x}P{sub 3}O{sub 9}{center_dot}3H{sub 2}O have been synthesized with x=5x10{sup -3}, 10{sup -2}, 5x10{sup -2}, 10{sup -1} and 1. Absorbance spectra were measured at 300 K in the 300-1000 nm region. Fluorescent emissions from the {sup 4}F{sub 3/2} multiplet were observed at 300 and 6 K under pulsed laser excitations in either the {sup 4}F{sub 7/2} or {sup 4}F{sub 3/2} multiplet and the decays of these emissions were measured. These decays are exponential with decay-times on the order of 100 ns for all values of x. No important lengthening is observed as either the Nd concentration is decreased from 100 to 0.5 at% or the temperature is lowered from 300 to 6 K. These results are in contradiction with those obtained for the anhydrous La{sub 1-x}Nd{sub x}(PO{sub 3}){sub 3} compounds prepared by progressively heating the corresponding La{sub 1-x}Nd{sub x}P{sub 3}O{sub 9}{center_dot}3H{sub 2}O powder materials, a fact which shows the predominant role played by the water molecules in the Nd{sup 3+} luminescence in the considered hydrated compounds.

  3. Raman spectroscopic determination of norbixin and tartrazine in sugar.

    Science.gov (United States)

    Uhlemann, Ute; Strelau, Katharina K; Weber, Karina; Da Costa Filho, Paulo Augusto; Rösch, Petra; Popp, Jürgen

    2012-08-01

    In this paper, a method for the detection of norbixin and tartrazine in sugar by means of resonance Raman spectroscopy is presented. The extraction was done in four steps using methanol and the measurements were performed in aqueous solution. The excitation wavelength was 514 nm for norbixin and 488 nm for tartrazine samples. The characteristic resonance Raman signals of the dyes were fitted by different functions. Depending on the R² values of the different fits, each spectrum was classified as positive or negative response. A detection limit of 250 ng g⁻¹ for norbixin and 989 ng g⁻¹ for tartrazine in solid sugar samples could be reached by logistic regression.

  4. A Combined Remote LIBS and Raman Spectroscopic Study of Minerals

    Science.gov (United States)

    Hubble, H. W.; Ghosh, M.; Sharma, S. K.; Horton, K. A.; Lucey, P. G.; Angel, S. M.; Wiens, R. C.

    2002-01-01

    In this paper, we explore the use of remote LIBS combined with pulsed-laser Raman spectroscopy for mineral analysis at a distance of 10 meters. Samples analyzed include: carbonates (both biogenic and abiogenic), silicates, and sulfates. Additional information is contained in the original extended abstract.

  5. RAMAN SPECTROSCOPIC ANALYSIS OF FERTILIZERS AND PLANT TISSUE FOR PERCHLORATE

    Science.gov (United States)

    Raman spectroscopy, without the need for prior chromatographic separation, was used for qualitative and quantitative analysis of 59 samples of fertilizers for perchlorate (ClO4-). These primarily lawn and garden products had no known link to Chile saltpeter, which is known to con...

  6. Lanthanum trilactate: Vibrational spectroscopic study - infrared/Raman spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Švecová, M.; Novák, Vít; Bartůněk, V.; Člupek, M.

    2016-01-01

    Roč. 87, Nov (2016), s. 123-128 ISSN 0924-2031 Institutional support: RVO:61388963 Keywords : lanthanum trilactate * tris(2-hydroxypropanoato-O1,O2) * lanthanum tris[2-(hydroxy-kappa O)propanoato-kappa O] * Raman spectra * infrared spectra * DFT Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.740, year: 2016

  7. Raman spectroscopic study of ancient South African domestic clay pottery

    Science.gov (United States)

    Legodi, M. A.; de Waal, D.

    2007-01-01

    The technique of Raman spectroscopy was used to examine the composition of ancient African domestic clay pottery of South African origin. One sample from each of four archaeological sites including Rooiwal, Lydenburg, Makahane and Graskop was studied. Normal dispersive Raman spectroscopy was found to be the most effective analytical technique in this study. XRF, XRD and FT-IR spectroscopy were used as complementary techniques. All representative samples contained common features, which were characterised by kaolin (Al 2Si 2O 5(OH) 5), illite (KAl 4(Si 7AlO 20)(OH) 4), feldspar (K- and NaAlSi 3O 8), quartz (α-SiO 2), hematite (α-Fe 2O 3), montmorillonite (Mg 3(Si,Al) 4(OH) 2·4.5H 2O[Mg] 0.35), and calcium silicate (CaSiO 3). Gypsum (CaSO 4·2H 2O) and calcium carbonates (most likely calcite, CaCO 3) were detected by Raman spectroscopy in Lydenburg, Makahane and Graskop shards. Amorphous carbon (with accompanying phosphates) was observed in the Raman spectra of Lydenburg, Rooiwal and Makahane shards, while rutile (TiO 2) appeared only in Makahane shard. The Raman spectra of Lydenburg and Rooiwal shards further showed the presence of anhydrite (CaSO 4). The results showed that South African potters used a mixture of clays as raw materials. The firing temperature for most samples did not exceed 800 °C, which suggests the use of open fire. The reddish brown and grayish black colours were likely due to hematite and amorphous carbon, respectively.

  8. Raman spectroscopic study on the excystation process in a single unicellular organism amoeba (Acanthamoeba polyphaga)

    Science.gov (United States)

    Lin, Yu-Chung; Perevedentseva, Elena; Cheng, Chia-Liang

    2015-05-01

    An in vivo Raman spectroscopic study of amoeba (Acanthamoeba polyphaga) is presented. The changes of the spectra during the amoeba cyst activation and excystation are analyzed. The spectra show the changes of the relative intensities of bands corresponding to protein, lipid, and carotenoid components during cyst activation. The presence of carotenoids in the amoeba is observed via characteristic Raman bands. These signals in the Raman spectra are intense in cysts but decrease in intensity with cyst activation and exhibit a correlation with the life cycle of amoeba. This work demonstrates the feasibility of using Raman spectroscopy for the detection of single amoeba microorganisms in vivo and for the analysis of the amoeba life activity. The information obtained may have implications for the estimation of epidemiological situations and for the diagnostics and prognosis of the development of amoebic inflammations.

  9. A Raman spectroscopic study of barium copper oxide

    International Nuclear Information System (INIS)

    Loo, B.H.; burns, D.H.; Roloin, T.D.

    1989-01-01

    Various physical treatments of BaCuO 2 samples result in irreversible changes in its Raman spectrum. The prominent peaks at 576 and 628 cm -1 in the spectra of sintered pellets of BaCuO 2 disappear upon further annealing in air or oxygen or upon mere regrinding of the pellets. Further annealing in air, oxygen, or vacuum does not restore these peaks. Similar but less intense peaks reappear upon exposure of pellets to laboratory environment for several weeks, but these broaden and disappear upon further exposure. These spectral characteristics contrast with those observed in Y123 Raman spectrum. It is concluded that the peaks at 582 cm -1 and 636 cm -1 in the spectra of sintered pellets of Y123 are not due to the presence of BaCuO 2

  10. Normal Raman and surface enhanced Raman spectroscopic experiments with thin layer chromatography spots of essential amino acids using different laser excitation sources

    Science.gov (United States)

    István, Krisztina; Keresztury, Gábor; Szép, Andrea

    2003-06-01

    A comparative study of the feasibility and efficiency of Raman spectroscopic detection of thin layer chromatography (TLC) spots of some weak Raman scatterers (essential amino acids, namely, glycine and L-forms of alanine, serine, valine, proline, hydroxyproline, and phenylalanine) was carried out using four different visible and near-infrared (NIR) laser radiations with wavelengths of 532, 633, 785, and 1064 nm. Three types of commercial TLC plates were tested and the possibility of inducing surface enhanced Raman scattering (SERS) by means of Ag-sol was also investigated. The spectra obtained from spotted analytes adsorbed on TLC plates were of very different quality strongly depending on the excitation wavelength, the wetness of the samples, and the compounds examined. The best results were obtained with the simple silica TLC plate, and it has been established that the longest wavelength (lowest energy) NIR excitation of a Nd:YAG laser is definitely more suitable for generating normal Raman scattering of analyte spots than any of the visible radiations. Concerning SERS with application of Ag-sol to the TLC spots, 1-3 orders of magnitude enhancement was observed with wet samples, the greatest with the 532 nm radiation and gradually smaller with the longer wavelength excitations. It is shown, however, that due to severe adsorption-induced spectral distortions and increased sensitivity to microscopic inhomogeneity of the sample, none of the SERS spectra obtained with the dispersive Raman microscope operating in the visible region were superior to the best NIR normal FT-Raman spectra, as far as sample identification is concerned.

  11. Raman Spectroscopic Analyses of Jaw Periosteal Cell Mineralization

    Directory of Open Access Journals (Sweden)

    Eva Brauchle

    2017-01-01

    Full Text Available To achieve safer patient treatments, serum-free cell culture conditions have to be established for cell therapies. In previous studies, we demonstrated that serum-free culture favored the proliferation of MSCA-1+ osteoprogenitors derived from the jaw periosteum. In this study, the in vitro formation of bone-specific matrix by MSCA-1+ jaw periosteal cells (JPCs, 3 donors was assessed and compared under serum-free and serum-containing media conditions using the marker-free Raman spectroscopy. Based on a standard fluorescence assay, JPCs from one patient were not able to mineralize under serum-containing culture conditions, whereas the other cells showed similar mineralization levels under both conditions. Raman spectra from mineralizing MSCA-1+ JPCs revealed higher levels of hydroxyapatite formation and higher mineral to matrix ratios under serum-free culture conditions. Higher carbonate to phosphate ratios and higher crystallinity in JPCs cultured under serum-containing conditions indicated immature bone formation. Due to reduced collagen production under serum-free conditions, we obtained significant differences in collagen maturity and proline to hydroxyproline ratios compared to serum-free conditions. We conclude that Raman spectroscopy is a useful tool for the assessment and noninvasive monitoring of in vitro mineralization of osteoprogenitor cells. Further studies should extend this knowledge and improve JPC mineralization by optimizing culture conditions.

  12. Utilizing Raman Spectroscopy and Surface-Enhanced Raman Spectroscopy to investigate healthy and cancerous colon samples

    International Nuclear Information System (INIS)

    Barzegar, A.; Rezaei, H.; Malekfar, R.

    2012-01-01

    In this study, spontaneous Raman scattering and surface-enhanced Raman scattering, Surface-Enhanced Raman Spectroscopy spectra have been investigated. The samples which were kept in the formalin solution selected from the human's healthy and cancerous colon tissues. The Surface-Enhanced Raman Spectroscopy spectra were collected by adding colloidal solution contained silver nanoparticles to the top of the samples. The recorded spectra were compared for the spontaneous Raman spectra of healthy and cancerous colon samples. The spontaneous and surface enhanced Raman scattering data were also collected and compared for both healthy and damaged samples.

  13. Polarized Raman spectroscopic characterization of normal and oral cancer blood plasma

    Science.gov (United States)

    Pachaiappan, Rekha; Prakasarao, Aruna; Singaravelu, Ganesan

    2017-02-01

    In India oral cancer ranks the top due to the habitual usage of tobacco in its various forms and remains the major burden. Hence priority is given for early diagnosis as it is the better solution for cure or to improve the survival rate. For the past three decades, optical spectroscopic techniques have shown its capacity in the discrimination of normal and malignant samples. Many research works have conventional Raman in the effective detection of cancer using the variations in bond vibrations of the molecules. However in addition polarized Raman provides the orientation and symmetry of biomolecules. If so can polarized Raman be the better choice than the conventional Raman in the detection of cancer? The present study aimed to found the answer for the above query. The conventional and polarized Raman spectra were acquired for the same set of blood plasma samples of normal subjects and oral malignant (OSCC) patients. Thus, obtained Raman spectral data were compared using linear discriminant analysis coupled with artificial neural network (LDA-ANN). The depolarization ratio of biomolecules such as antioxidant, amino acid, protein and nucleic acid bases present in blood plasma was proven to be the best attributes in the categorization of the groups. The polarized Raman results were promising in discriminating oral cancer blood plasma from that of normal blood plasma with improved efficiency. The results will be discussed in detail.

  14. Raman spectroscopic studies on exfoliated cells of oral and cervix

    Science.gov (United States)

    Hole, Arti; Sahu, Aditi; Shaikh, Rubina; Tyagi, Gunjan; Murali Krishna, C.

    2018-01-01

    Visual inspection followed by biopsy is the standard procedure for cancer diagnosis. Due to invasive nature of the current diagnostic methods, patients are often non-compliant. Hence, it is necessary to explore less invasive and rapid methods for early detection. Exfoliative cytology is a simple, rapid, and less invasive technique. It is thus well accepted by patients and is suitable for routine applications in population screening programs. Raman spectroscopy (RS) has been increasingly explored for disease diagnosis in the recent past. In vivo RS has previously shown promise in management of both oral and cervix cancers. In vivo applications require on-site instrumentation and stringent experimental conditions. Hence, RS of less invasive samples like exfoliated cells has been explored, as this facilitates collection at multiple screening centers followed by analysis at a centralized facility. In the present study, efficacy of Raman spectroscopy in classification of 15 normal and 29 abnormal oral exfoliated cells specimens and 28 normal and 38 abnormal cervix specimens were explored. Spectra were acquired by Raman microprobe (HE 785, Horiba-Jobin-Yvon, France) from several areas to span the pellet. Spectral acquisition parameters were: microscopic objective: 40X, power: 40 mW, acquisition time: 15 s and average: 3. PCA and PC-LDA of pre-processed spectra was carried out on a 4-model system of normal and tumor of both cervix and oral specimens. Leave-one-out-cross-validation findings indicate 73 % correct classification. Findings suggest RS of exfoliated cells may serve as a patient-friendly, non-invasive, rapid and objective method for management of cervix and oral cancers.

  15. Raman spectroscopic approach to monitor the in vitro cyclization of creatine → creatinine

    Science.gov (United States)

    Gangopadhyay, Debraj; Sharma, Poornima; Singh, Sachin Kumar; Singh, Pushkar; Tarcea, Nicolae; Deckert, Volker; Popp, Jürgen; Singh, Ranjan K.

    2015-01-01

    The creatine → creatinine cyclization, an important metabolic phenomenon has been initiated in vitro at acidic pH and studied through Raman spectroscopic and DFT approach. The equilibrium composition of neutral, zwitterionic and protonated microspecies of creatine has been monitored with time as the reaction proceeds. Time series Raman spectra show clear signature of creatinine formation at pH 3 after ∼240 min at room temperature and reaction is faster at higher temperature. The spectra at pH 1 and pH 5 do not show such signature up to 270 min implying faster reaction rate at pH 3.

  16. Vibrational spectroscopic investigation of polymorphs and cocrystals of indomethacin.

    Science.gov (United States)

    Ali, Hassan Refat H; Alhalaweh, Amjad; Velaga, Sitaram P

    2013-05-01

    Identification of optimal solid form of an active pharmaceutical ingredient and form control are very important in drug development. Thus, the structural information of these forms and in-depth insight on the modes of molecular interactions are necessary, and vibrational spectroscopic methods are well suited for this purpose. In-depth structural analysis of different solid forms of indomethacin (IND) using Raman and infrared (IR) spectroscopy is the objective. We have investigated the modes of molecular interactions in polymorphs (α and γ), amorphous and discovered cocrystals of IND with nicotinamide (NIC) and trans-cinnamic acid (CIN) coformers. The solid forms of IND have been prepared; their purity has been verified by differential scanning calorimetry and powder X-ray diffractometry and then studied in the solid-state by Raman and IR spectroscopy. The modes of the interactions were closely investigated from the vibrational data. The key vibrational features of IND solid forms have been specified. The IR (C=O) band at 1713 cm(-1) attributed to cyclic acid dimer of γ IND has disappeared in IND-NIC/CIN whilst retained in IND-SAC cocrystal. IND cocrystallizes in different conformations and crystal lattices with different coformers. The cyclic acid dimer of IND has been kept on its cocrystallization with saccharin and it could have been broken with NIC and CIN. The complementary nature of Raman and IR spectroscopy allowed unambiguous investigation of the chemical composition of pharmaceutical materials which is of particular importance in the absence of detailed structural information, as in the case of IND-NIC and IND-CIN.

  17. Comparative FT-Raman, FT-IR and colour shifts spectroscopic evaluation of gamma irradiated experimental models of oil paintings

    International Nuclear Information System (INIS)

    Manca, M.M.; Virgolici, M.; Cutrubinis, M.; Moise, I.V.; Ponta, C.C.; Negut, C.D.; Stanculescu, I.R.; Bucharest University

    2011-01-01

    Complete text of publication follows. The present study follows the changes of gamma irradiated historic pigments and experimental models of oil paintings with non-destructive and non-contact spectroscopic analytical techniques which are the only ones accepted by the conservators/restorers community. Molecular structure characterization was performed by FT-IR / Raman spectroscopy using a Bruker Vertex 70 class equipped with two mobile probes: a MIR fibre module for MIR probes (with LN2 cooled detector) and a Raman RAM II module (LN2 Ge detector) with a RAMPROBE fibre. Colour was measured by a portable reflectance spectrophotometer (Miniscan XE Plus, HunterLab) in diffuse/8 deg geometry with a beam diameter of 4 mm and specular component included. Correlations between colour shifts and changes in molecular structure induced by gamma irradiation were further investigated.

  18. Biodegradable starch-based films containing saturated fatty acids: thermal, infrared and raman spectroscopic characterization

    Directory of Open Access Journals (Sweden)

    Marcelo M. Nobrega

    Full Text Available Biodegradable films of thermoplastic starch and poly (butylene adipate co-terephthalate (PBAT containing fatty acids were characterized thermally and with infrared and Raman spectroscopies. The symmetrical character of the benzene ring in PBAT provided a means to illustrate the difference between these spectroscopic techniques, because a band appeared in the Raman spectrum but not in the infrared. The thermal analysis showed three degradation stages related to fatty acids, starch and PBAT. The incorporation of saturated fatty acids with different molecular mass (caproic, lauric and stearic did not change the nature of the chemical bonds among the components in the blends of starch, PBAT and glycerol, according to the thermal analysis, infrared and Raman spectroscopies.

  19. Raman spectroscopic analysis of the Maya wall paintings in Ek'Balam, Mexico

    Science.gov (United States)

    Vandenabeele, P.; Bodé, S.; Alonso, A.; Moens, L.

    2005-08-01

    Raman spectroscopy has been applied to the examination of wall painting fragments from the archaeological site of Ek'Balam (Yucatán, Mexico). Thirty-three samples have been studied, all originating from room 23 of the Acropolis, and being representative of the painting technique at Ek'Balam during the late Classic Maya period. Several pigments such as haematite, calcite, carbon, cinnabar and indigo were identified in these samples. The latter pigment was presumed to be present as 'Maya blue', which is an intercalation product of indigo and palygorskite clay. The observed Raman spectra are reported and some band assignments have been made. This survey is the first Raman spectroscopic examination of a whole set of pigments in archaeological Maya wall painting fragments.

  20. Doping of C-70 fullerene peapods with lithium vapor: Raman spectroscopic and Raman spectroelectrochemical studies

    Czech Academy of Sciences Publication Activity Database

    Kalbáč, Martin; Valeš, Václav; Kavan, Ladislav; Dunsch, L.

    2014-01-01

    Roč. 25, č. 48 (2014), 485706 ISSN 0957-4484 R&D Projects: GA ČR GAP204/10/1677 Institutional support: RVO:61388955 Keywords : fullerene peapods * Raman spectroelectrochemistry * Li doping Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.821, year: 2014

  1. Potential drug – nanosensor conjugates: Raman, infrared absorption, surface – enhanced Raman, and density functional theory investigations of indolic molecules

    Energy Technology Data Exchange (ETDEWEB)

    Pięta, Ewa, E-mail: Ewa.Pieta@ifj.edu.pl [Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Krakow (Poland); Paluszkiewicz, Czesława [Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Krakow (Poland); Oćwieja, Magdalena [J. Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, PL-30239 Krakow (Poland); Kwiatek, Wojciech M. [Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Krakow (Poland)

    2017-05-15

    Highlights: • Molecular fragments involved in the adsorption process were determined. • Formation of hydrogen bonds with the negatively charged gold substrates was observed. • Indole moiety strongly interacts with gold nanosensors. • The synthesized sensors are characterized by high stability and reproducibility. • Chemical mechanism plays a crucial role in the enhancement of the Raman signal. - Abstract: An extremely important aspect of planning cancer treatment is not only the drug efficiency but also a number of challenges associated with the side effects and control of this process. That is why it is worth paying attention to the promising potential of the gold nanoparticles combined with a compound treated as a potential drug. This work presents Raman (RS), infrared absorption (IR) and surface–enhanced Raman scattering (SERS) spectroscopic investigations of N–acetyl–5–methoxytryptamine (melatonin) and α–methyl–DL–tryptophan, regarding as anti breast cancer agents. The experimental spectroscopic analysis was supported by the quantum-chemical calculations based on the B3LYP hybrid density functional theory (DFT) at the B3LYP 6–311G(d,p) level of theory. The studied compounds were adsorbed onto two colloidal gold nanosensors synthesized by a chemical reduction method using sodium borohydride (SB) and trisodium citrate (TC), respectively. Its morphology characteristics were obtained using transmission electron microscopy (TEM). It has been suggested that the NH moiety from the aromatic ring, a well-known proton donor, causes the formation of hydrogen bonds with the negatively charged gold surface.

  2. Raman spectroscopic analysis for gastric and colorectal cancer in surgical treatment toward molecular-guided surgery

    Science.gov (United States)

    Koga, Shigehiro; Watanabe, Yuji; Oshima, Yusuke

    2018-02-01

    Raman spectroscopy provides a wealth of diagnostic information to the surgeon with in situ cancer detection and label-free histopathology in intraoperative conditions. Raman spectroscopy is a promising optical technique which can analyze biological tissues with light scattering. The difference in frequencies between the incident light and the scattering light are called Raman shifts, which correspond to the vibrational energy of the molecular bonds. Raman spectrum gives information about the molecular structure and composition in biological specimens. We had been previously reported that Raman spectroscopy could distinguish various histological types of human lung cancer cells from normal cells in vitro, and also confirmed that Raman spectra obtained from cancer cells and their environment including other cells and extracellular matrix in xenograft models and spontaneous metastasis models were distinguishable using Raman spectroscopy combined with fluorescence microscopy and photoluminescence imaging. Malignancy can be characterized not only by the cancer cells but also by the environmental factors including immune cells, stroma cells, secretion vesicles and extracellular matrix, but to identify and detect cancer diagnostic biomarkers in vivo on Raman spectroscopy is still challenging. Here we investigate morphological and molecular dynamics in advanced cancer specimens obtained from patients. We are also constructing a customdesigned Raman spectral imaging system for both in vitro and in vivo assay of tumor tissues to reveal the metastasis process and to evaluate therapeutic effects of anti-cancer drugs and their drug delivery toward the clinical application of the technique.

  3. Raman spectroscopic study of keratin 8 knockdown oral squamous cell carcinoma derived cells

    Science.gov (United States)

    Singh, S. P.; Alam, Hunain; Dmello, Crismita; Vaidya, Milind M.; Krishna, C. Murali

    2012-03-01

    Keratins are one of most widely used markers for oral cancers. Keratin 8 and 18 are expressed in simple epithelia and perform both mechanical and regulatory functions. Their expression are not seen in normal oral tissues but are often expressed in oral squamous cell carcinoma. Aberrant expression of keratins 8 and 18 is most common change in human oral cancer. Optical-spectroscopic methods are sensitive to biochemical changes and being projected as novel diagnostic tools for cancer diagnosis. Aim of this study was to evaluate potentials of Raman spectroscopy in detecting minor changes associated with differential level of keratin expression in tongue-cancer-derived AW13516 cells. Knockdown clones for K8 were generated and synchronized by growing under serum-free conditions. Cell pellets of three independent experiments in duplicate were used for recording Raman spectra with fiberoptic-probe coupled HE-785 Raman-instrument. A total of 123 and 96 spectra from knockdown clones and vector controls respectively in 1200-1800 cm-1 region were successfully utilized for classification using LDA. Two separate clusters with classification-efficiency of ~95% were obtained. Leave-one-out cross-validation yielded ~63% efficiency. Findings of the study demonstrate the potentials of Raman spectroscopy in detecting even subtle changes such as variations in keratin expression levels. Future studies towards identifying Raman signals from keratin in oral cells can help in precise cancer diagnosis.

  4. FTIR and Raman spectroscopic studies of selenium nanoparticles synthesised by the bacterium Azospirillum thiophilum

    Science.gov (United States)

    Tugarova, Anna V.; Mamchenkova, Polina V.; Dyatlova, Yulia A.; Kamnev, Alexander A.

    2018-03-01

    Vibrational (Fourier transform infrared (FTIR) and Raman) spectroscopic techniques can provide unique molecular-level information on the structural and compositional characteristics of complicated biological objects. Thus, their applications in microbiology and related fields are steadily increasing. In this communication, biogenic selenium nanoparticles (Se NPs) were obtained via selenite (SeO32-) reduction by the bacterium Azospirillum thiophilum (strain VKM B-2513) for the first time, using an original methodology for obtaining extracellular NPs. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed the Se NPs to have average diameters within 160-250 nm; their zeta potential was measured to be minus 18.5 mV. Transmission FTIR spectra of the Se NPs separated from bacterial cells showed typical proteinacious, polysaccharide and lipid-related bands, in line with TEM data showing a thin layer covering the Se NPs surface. Raman spectra of dried Se NPs layer in the low-frequency region (under 500 cm-1 down to 150 cm-1) showed a single very strong band with a maximum at 250 cm-1 which, in line with its increased width (ca. 30 cm-1 at half intensity), can be attributed to amorphous elementary Se. Thus, a combination of FTIR and Raman spectroscopic approaches is highly informative in non-destructive analysis of structural and compositional properties of biogenic Se NPs.

  5. Reduced and oxidised scytonemin: theoretical protocol for Raman spectroscopic identification of potential key biomolecules for astrobiology.

    Science.gov (United States)

    Varnali, Tereza; Edwards, Howell G M

    2014-01-03

    Scytonemin is an important UV-radiation protective biomolecule synthesised by extremophilic cyanobacteria in stressed terrestrial environments. Scytonemin and its reduced form have been both isolated experimentally and the Raman spectrum for scytonemin has been assigned and characterised experimentally both in extracts and in living extremophilic cyanobacterial colonies. Scytonemin is recognised as a key biomarker molecule for terrestrial organisms in stressed environments. We propose a new, theoretically plausible structure for oxidised scytonemin which has not been mentioned in the literature hitherto. DFT calculations for scytonemin, reduced scytonemin and the new structure modelled and proposed for oxidised scytonemin are reported along with their Raman spectroscopic data and λmax UV-absorption data obtained theoretically. Comparison of the vibrational spectroscopic assignments allows the three forms of scytonemin to be detected and identified and assist not only in the clarification of the major features in the experimentally observed Raman spectral data for the parent scytonemin but also support a protocol proposed for their analytical discrimination. The results of this study provide a basis for the search for molecules of this type in future astrobiological missions of exploration and the search for extinct and extant life terrestrially. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Defects in Individual Semiconducting Single Wall Carbon Nanotubes: Raman Spectroscopic and in Situ Raman Spectroelectrochemical Study

    Czech Academy of Sciences Publication Activity Database

    Kalbáč, Martin; Hsieh, Y. P.; Farhat, H.; Kavan, Ladislav; Hofmann, M.; Kong, J.; Dresselhaus, M. S.

    2010-01-01

    Roč. 10, č. 11 (2010), s. 4619-4626 ISSN 1530-6984 R&D Projects: GA ČR GC203/07/J067; GA AV ČR IAA400400804; GA AV ČR IAA400400911; GA AV ČR KAN200100801; GA MŠk ME09060 Institutional research plan: CEZ:AV0Z40400503 Keywords : single wall carbon nanotubes * Raman spectroscopy * defects Subject RIV: CG - Electrochemistry Impact factor: 12.186, year: 2010

  7. Comparison between infrared and Raman spectroscopic analysis of maturing rabbit cortical bone.

    Science.gov (United States)

    Turunen, Mikael J; Saarakkala, Simo; Rieppo, Lassi; Helminen, Heikki J; Jurvelin, Jukka S; Isaksson, Hanna

    2011-06-01

    The molecular composition of the organic and inorganic matrices of bone undergoes alterations during maturation. The aim of this study was to compare Fourier transform infrared (FT-IR) and near-infrared (NIR) Raman microspectroscopy techniques for characterization of the composition of growing and developing bone from young to skeletally mature rabbits. Moreover, the specificity and differences of the techniques for determining bone composition were clarified. The humeri of female New Zealand White rabbits, with age range from young to skeletally mature animals (four age groups, n = 7 per group), were studied. Spectral peak areas, intensities, and ratios related to organic and inorganic matrices of bone were analyzed and compared between the age groups and between FT-IR and Raman microspectroscopic techniques. Specifically, the degree of mineralization, type-B carbonate substitution, crystallinity of hydroxyapatite (HA), mineral content, and collagen maturity were examined. Significant changes during maturation were observed in various compositional parameters with one or both techniques. Overall, the compositional parameters calculated from the Raman spectra correlated with analogous parameters calculated from the IR spectra. Collagen cross-linking (XLR), as determined through peak fitting and directly from the IR spectra, were highly correlated. The mineral/matrix ratio in the Raman spectra was evaluated with multiple different peaks representing the organic matrix. The results showed high correlation with each other. After comparison with the bone mineral density (BMD) values from micro-computed tomography (micro-CT) imaging measurements and crystal size from XRD measurements, it is suggested that Raman microspectroscopy is more sensitive than FT-IR microspectroscopy for the inorganic matrix of the bone. In the literature, similar spectroscopic parameters obtained with FT-IR and NIR Raman microspectroscopic techniques are often compared. According to the present

  8. Raman spectroscopic study of “The Malatesta”: A Renaissance painting?

    Science.gov (United States)

    Edwards, Howell G. M.; Vandenabeele, Peter; Benoy, Timothy J.

    2015-02-01

    Raman spectroscopic analysis of the pigments on an Italian painting described as a "Full Length Portrait of a Gentleman", known also as the "Malatesta", and attributed to the Renaissance period has established that these are consistent with the historical research provenance undertaken earlier. Evidence is found for the early 19th Century addition of chrome yellow to highlighted yellow ochre areas in comparison with a similar painting executed in 1801 by Sir Thomas Lawrence of John Kemble in the role of Hamlet, Prince of Denmark. The Raman data are novel in that no analytical studies have previously been made on this painting and reinforces the procedure whereby scientific analyses are accompanied by parallel historical research.

  9. Raman spectroscopic sensing of carbonate intercalation in breast microcalcifications at stereotactic biopsy

    Science.gov (United States)

    Sathyavathi, R.; Saha, Anushree; Soares, Jaqueline S.; Spegazzini, Nicolas; McGee, Sasha; Rao Dasari, Ramachandra; Fitzmaurice, Maryann; Barman, Ishan

    2015-04-01

    Microcalcifications are an early mammographic sign of breast cancer and frequent target for stereotactic biopsy. Despite their indisputable value, microcalcifications, particularly of the type II variety that are comprised of calcium hydroxyapatite deposits, remain one of the least understood disease markers. Here we employed Raman spectroscopy to elucidate the relationship between pathogenicity of breast lesions in fresh biopsy cores and composition of type II microcalcifications. Using a chemometric model of chemical-morphological constituents, acquired Raman spectra were translated to characterize chemical makeup of the lesions. We find that increase in carbonate intercalation in the hydroxyapatite lattice can be reliably employed to differentiate benign from malignant lesions, with algorithms based only on carbonate and cytoplasmic protein content exhibiting excellent negative predictive value (93-98%). Our findings highlight the importance of calcium carbonate, an underrated constituent of microcalcifications, as a spectroscopic marker in breast pathology evaluation and pave the way for improved biopsy guidance.

  10. Raman spectroscopic differentiation of beef and horse meat using a 671 nm microsystem diode laser

    Science.gov (United States)

    Ebrahim, Halah Al; Sowoidnich, Kay; Kronfeldt, Heinz-Detlef

    2013-11-01

    A non-invasive Raman spectroscopic approach for meat species identification and quality detection was successfully demonstrated for the two closely related species beef and horse. Fresh beef and horse muscles were cut and ice-stored at 5 °C, and time-dependent Raman measurements were performed daily up to 12 days postmortem. Applying a 671 nm microsystem diode laser and a laser power of 50 mW, spectra were recorded with integration times of 1-4 s. A pronounced offset of the Raman spectra was observed between horse and beef, with high fluorescence background for horse compared to beef for all days of storage. Principal components analysis was applied for data evaluation revealing a clear distinction between beef and horse meat which can be attributed to differences in the myoglobin content of both species. Furthermore, separations according to aging and spoilage for the two species could be identified simultaneously. Therefore, Raman spectroscopy might be an efficient test method for meat species identification in combination with spoilage detection.

  11. A Raman spectroscopic study of thermally treated glushinskite--the natural magnesium oxalate dihydrate.

    Science.gov (United States)

    Frost, Ray L; Adebajo, Moses; Weier, Matt L

    2004-02-01

    Raman spectroscopy has been used to study the thermal transformations of natural magnesium oxalate dihydrate known in mineralogy as glushinskite. The data obtained by Raman spectroscopy was supplemented with that of infrared emission spectroscopy. The vibrational spectroscopic data was complimented with high resolution thermogravimetric analysis combined with evolved gas mass spectrometry. TG-MS identified two mass loss steps at 146 and 397 degrees C. In the first mass loss step water is evolved only, in the second step carbon dioxide is evolved. The combination of Raman microscopy and a thermal stage clearly identifies the changes in the molecular structure with thermal treatment. Glushinskite is the dihydrate phase in the temperature range up to the pre-dehydration temperature of 146 degrees C. Above 397 degrees C, magnesium oxide is formed. Infrared emission spectroscopy shows that this mineral decomposes at around 400 degrees C. Changes in the position and intensity of the CO and CC stretching vibrations in the Raman spectra indicate the temperature range at which these phase changes occur.

  12. Investigation of biomineralization by Raman spectroscopy

    Science.gov (United States)

    Fatscher, Robert William

    implants. These implants are designed to osteointegrate with the native healthy tissues in order to create a functionally stable and structural interface. Biomaterials such as hydroxyapatite and titania are known to increase the rate of bone regeneration in vivo.1 By accelerating the early response of bone forming cells to these implants, better fixation is achieved between the implant and the bone, shortening recovery times and increasing the viability of these implants. In the last part of this research an investigation of osteoblasts cultured at 14 days on five different heat-treated titania substrates was investigated by Raman spectroscopy, in order to observe the initial cellular response to the titania substrates. The heat-treatment of titania changes the amount of oxygen on it's surface which in turn effects the surface energy. A change in the surface energy of a material will affect the cellular response, by culturing cells on various heat-treated titania substrates a relationship between the surface energy and cellular response can be investigated. A faster cellular response would lead to an increased rate of bone regeneration shortening healing times and allowing for better fixation of the implant.

  13. Vacuum arc anode plasma. I. Spectroscopic investigation

    International Nuclear Information System (INIS)

    Bacon, F.M.

    1975-01-01

    A spectroscopic investigation was made of the anode plasma of a pulsed vacuum arc with an aluminum anode and a molybdenum cathode. The arc was triggered by a third trigger electrode and was driven by a 150-A 10-μs current pulse. The average current density at the anode was sufficiently high that anode spots were formed; these spots are believed to be the source of the aluminum in the plasma investigated in this experiment. By simultaneously measuring spectral emission lines of Al I, Al II, and Al III, the plasma electron temperature was shown to decrease sequentially through the norm temperatures of Al III, Al II, and Al I as the arc was extinguished. The Boltzmann distribution temperature T/subD/ of four Al III excited levels was shown to be kT/subD//e=2.0plus-or-minus0.5 V, and the peak Al III 4D excited state density was shown to be about 5times10 17 m -3 . These data suggest a non-local-thermodynamic-equilibrium (non-LTE) model of the anode plasma when compared with the Al 3+ production in the plasma. The plasma was theoretically shown to be optically thin to the observed Al III spectral lines

  14. Investigations of a Dual Seeded 1178 nm Raman Laser System

    Science.gov (United States)

    2016-01-14

    was obtained by Raman amplification of a distributed feedback diode laser in a variably strained polarization- maintaining fiber with a record-high...Calia, D.B., “50W CW visible laser source at 589 nm obtained via frequency doubling of three coherently combined narrow-band Raman fiber amplifiers...AFRL-RD-PS- TP-2016-0009 AFRL-RD-PS- TP-2016-0009 INVESTIGATIONS OF A DUAL SEEDED 1178 NM RAMAN LASER SYSTEM Leanne Henry, et al. 14 January

  15. Raman spectroscopic monitoring of the bioeffects of nitroglycerin on Hb-O II in single red blood cell

    Science.gov (United States)

    Chiang, Huihua Kenny; Ruan, Hung-Shiang; Cheng, Hung-You; Fang, Tung-Ting

    2007-02-01

    Raman spectroscopy has been shown to have the potential for providing oxygenated ability of erythrocytes. Raman line at 1638 cm-1 has also been reported as one significant oxygenic indicator for erythrocytes. In this research, we develop the Raman spectroscopic monitoring of the bioeffects of Nitroglycerin on hemoglobin oxygen saturation in a single red blood cell (RBC). Nitroglycerin has been frequently used in the management of angina pectoris. Nitroglycerin liberates nitric oxide (NO) to blood vessels. NO is an oxidizer that easily converts hemoglobin to methemoglobin. The conversion may cause the decrease of oxygenated ability of erythrocytes. In this study, we observed the oxidize state of erythrocytes caused by the over dosage of Nitroglycerin. When the dose of Nitroglycerin exceeds 2x10 -4 M, the oxygenic state of erythrocytes decreases significantly. The Raman spectroscopic results demonstrate the observation of the bioeffects of Nitroglycerin on hemoglobin.

  16. Comprehensive quantum chemical and spectroscopic (FTIR, FT-Raman, 1H, 13C NMR) investigations of O-desmethyltramadol hydrochloride an active metabolite in tramadol--an analgesic drug.

    Science.gov (United States)

    Arjunan, V; Santhanam, R; Marchewka, M K; Mohan, S

    2014-03-25

    O-desmethyltramadol is one of the main metabolites of tramadol widely used clinically and has analgesic activity. The FTIR and FT-Raman spectra of O-desmethyl tramadol hydrochloride are recorded in the solid phase in the regions 4000-400 cm(-1) and 4000-100 cm(-1), respectively. The observed fundamentals are assigned to different normal modes of vibration. Theoretical studies have been performed as its hydrochloride salt. The structure of the compound has been optimised with B3LYP method using 6-31G(**) and cc-pVDZ basis sets. The optimised bond length and bond angles are correlated with the X-ray data. The experimental wavenumbers were compared with the scaled vibrational frequencies determined by DFT methods. The IR and Raman intensities are determined with B3LYP method using cc-pVDZ and 6-31G(d,p) basic sets. The total electron density and molecular electrostatic potential surfaces of the molecule are constructed by using B3LYP/cc-pVDZ method to display electrostatic potential (electron+nuclei) distribution. The electronic properties HOMO and LUMO energies were measured. Natural bond orbital analysis of O-desmethyltramadol hydrochloride has been performed to indicate the presence of intramolecular charge transfer. The (1)H and (13)C NMR chemical shifts of the molecule have been anlysed. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Comprehensive quantum chemical and spectroscopic (FTIR, FT-Raman, (1)H, (13)C NMR) investigations of (1,2-epoxyethyl)benzene and (1,2-epoxy-2-phenyl)propane.

    Science.gov (United States)

    Arjunan, V; Anitha, R; Devi, L; Mohan, S; Yang, Haifeng

    2015-01-25

    Aromatic epoxides are causative factors for mutagenic and carcinogenic activity of polycyclic arenes. The 1,2- or 2,3-epoxy compounds are widely used to a considerable extent in the textile, plastics, pharmaceutical, cosmetics, detergent and photochemical industries. The FTIR and FT-Raman spectra of (1,2-epoxyethyl)benzene and (1,2-epoxy-2-phenyl)propane are recorded in the regions 4000-400 cm(-1) and 4000-100 cm(-1), respectively. The observed fundamentals are assigned to different normal modes of vibration. The structure of the compound has been optimised with B3LYP method using 6-311++G(**) and cc-pVTZ basis sets. The IR and Raman intensities are determined. The total electron density and molecular electrostatic potential surfaces of the molecule are constructed by using B3LYP/6-311++G(d,p) method to display electrostatic potential (electron+nuclei) distribution. The electronic properties HOMO and LUMO energies were measured. Natural bond orbital analysis of the compounds has been performed to indicate the presence of intramolecular charge transfer. The (1)H and (13)C NMR chemical shifts of the molecules have been analysed. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Feasibility study of Raman spectroscopy for investigating the mouse retina in vivo

    Science.gov (United States)

    Manna, Suman K.; de Oliveira, Marcos A. S.; Zhang, Pengfei; Maleppat, Ratheesh K.; Chang, Che-Wei; Pugh, Edward N.; Chan, James W.; Zawadzki, Robert J.

    2018-02-01

    The use of Raman spectroscopy in biochemistry has been very successful, particularly because of its ability to identify elementary chemical species. However, application of this spectroscopic technique for in vivo assessment is often limited by autofluorescence, which make detection of Raman signatures difficult. The mouse eye has been used as an optical testbed for investigation of a variety of disease models and therapeutic pathways. Implementation of in vivo Raman spectroscopy in mice retina would be valuable but needs to be examined in context of the intrinsic auto-fluorescence artifact and potential light damage if high probing beam powers were used. To evaluate feasibility, a Raman system was built on a custom SLO/OCT platform allowing mouse positioning and morphological data acquisition along with the Raman signal from a desired retinal eccentricity. The performance of the Raman system was first assessed with a model eye consisting of polystyrene in the image plane (retina), using excitation wavelengths of 488 nm, 561 nm, and 785 nm to determine whether auto-fluorescence would be reduced at longer wavelengths. To improve the SNR, the combined system is featured with the optical compatibility for these three excitations such that their corresponding spectra from a typical region of interest can be acquired consecutively during single imaging run. Our results include emission spectra acquired over 10 s with excitation energy less than 160 J.s-1.m-2 for all wavelengths and corresponding retinal morphology for different mouse strains including WT, BALB/c and ABCA4-/-.

  19. Spectroscopic investigation (FT-IR and FT-Raman), vibrational assignments, HOMO-LUMO analysis and molecular docking study of 1-hydroxy-4,5,8-tris(4-methoxyphenyl) anthraquinone

    Science.gov (United States)

    Renjith, R.; Sheena Mary, Y.; Tresa Varghese, Hema; Yohannan Panicker, C.; Thiemann, Thies; Shereef, Anas; Al-Saadi, Abdulaziz A.

    2015-12-01

    FT-IR and FT-Raman spectra of 1-hydroxy-4,5,8-tris(4-methoxyphenyl)anthraquinone were recorded and analyzed. The vibrational wavenumbers were computed using DFT quantum chemical calculations. The data obtained from wavenumber calculations were used to assign the vibrational bands obtained experimentally. A detailed molecular picture of the title compound and its interactions were obtained from NBO analysis. From the MEP plot it is clear that the negative electrostatic potential regions are mainly localized over carbonyl group. There is some evidence of a region of negative electrostatic potential due to π-electron density of the benzo groups. Molecular docking study shows that methoxy groups attached to the phenyl rings and hydroxyl group are crucial for binding and the title compound might exhibit inhibitory activity against PI3K and may act as an anti-neoplastic agent.

  20. RAMAN SPECTROSCOPIC STUDY ON PREDICTION OF TREATMENT RESPONSE IN CERVICAL CANCERS

    Directory of Open Access Journals (Sweden)

    S. RUBINA

    2013-04-01

    Full Text Available Concurrent chemoradiotherapy (CCRT is the choice of treatment for locally advanced cervical cancers; however, tumors exhibit diverse response to treatment. Early prediction of tumor response leads to individualizing treatment regimen. Response evaluation criteria in solid tumors (RECIST, the current modality of tumor response assessment, is often subjective and carried out at the first visit after treatment, which is about four months. Hence, there is a need for better predictive tool for radioresponse. Optical spectroscopic techniques, sensitive to molecular alteration, are being pursued as potential diagnostic tools. Present pilot study aims to explore the fiber-optic-based Raman spectroscopy approach in prediction of tumor response to CCRT, before taking up extensive in vivo studies. Ex vivo Raman spectra were acquired from biopsies collected from 11 normal (148 spectra, 16 tumor (201 spectra and 13 complete response (151 CR spectra, one partial response (8 PR spectra and one nonresponder (8 NR spectra subjects. Data was analyzed using principal component linear discriminant analysis (PC-LDA followed by leave-one-out cross-validation (LOO-CV. Findings suggest that normal tissues can be efficiently classified from both pre- and post-treated tumor biopsies, while there is an overlap between pre- and post-CCRT tumor tissues. Spectra of CR, PR and NR tissues were subjected to principal component analysis (PCA and a tendency of classification was observed, corroborating previous studies. Thus, this study further supports the feasibility of Raman spectroscopy in prediction of tumor radioresponse and prospective noninvasive in vivo applications.

  1. Raman Spectroscopic Studies of YBa{sub 2}Cu{sub 3}O{sub 7} Coated Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Mi Kyeung; Mnh, Nguyen Van; Bae, J. S.; Jo, William; Yang, In Sang [Ewha Womans University, Seoul (Korea, Republic of); Ko, Rock Kil; Ha, Hong Soo; Park, Chan [Korea Electrotecnology Research Institute, Changwon (Korea, Republic of)

    2005-04-15

    We present results of Raman spectroscopic studies of superconducting YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) coated conductors. Raman scattering is used to characterize optical phonon modes, oxygen content, c-axis misalignment, and second phases of the YBCO coated conductors at a micro scale. A two-dimensional mapping of Raman spectra with transport properties has been performed to elucidate the effect of local propertied on current path and superconducting phase. The information taken from the local measurement will be useful for optimizing the process condition.

  2. Raman Spectroelectrochemical Investigations of Immobilized Redox Proteins

    OpenAIRE

    Grochol, Jana

    2007-01-01

    Das Interesse an auf Elektroden immobilisierten Redoxproteinen ist in den letzten Jahren stark gestiegen. Die oberflächenverstärkte Resonanz-Raman- (SERR) Spektroelektrochemie eignet sich hervorragend zum Studium des heterogenen Elektronentransfers, da sie selektiv das Schwingungsspektrum der Redoxzentren der immobilisierten Spezies abfragt. SERR Spektroskopie kombiniert die Vorteile der Oberflächen- und Resonanz-Verstärkung, indem Hämproteine auf rauen Silberelektroden adsorbiert und in der ...

  3. Spectroscopic investigations on oxidized multi-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Anandhi, C. M. S.; Premkumar, S.; Asath, R. Mohamed; Mathavan, T.; Benial, A. Milton Franklin, E-mail: miltonfranklin@yahoo.com [Department of Physics, N.M.S.S.V.N. College, Madurai-625 019, Tamil Nadu (India)

    2016-05-06

    The pristine multi-walled carbon nanotubes (MWCNTs) were oxidized by the ultrasonication process. The oxidized MWCNTs were characterized by the X-ray diffraction (XRD), ultraviolet–visible (UV-Vis) and Fourier transform -Raman (FT-Raman) spectroscopic techniques. The XRD analysis confirms that the oxidized MWCNTs exist in a hexagonal structure and the sharp XRD peak corresponds to the (002) Bragg’s reflection plane, which indicates that the MWCNTs have higher crystalline nature. The UV-Vis analysis confirms that the MWCNTs functionalized with the carboxylic acid. The red shift was observed corresponds to the D band in the Raman spectrum, which reveals that the reduced disordered graphitic structure of oxidized MWCNTs. The strong Raman peak was observed at 2563 cm{sup -1} corresponds to the overtone of the D band, which is the characteristic vibrational mode of oxidized MWCNTs. The carboxylic acid functionalization of MWCNTs enhances the dispersibility, which paves the way for potential applications in the field of biosensors and targeted drug delivery.

  4. FT-Raman spectroscopic analysis of pigments from an Augustinian friary.

    Science.gov (United States)

    Edwards, Howell G M; Newton, Emma M; O'Connor, Sonia; Evans, D

    2010-08-01

    The Raman spectroscopic analysis of several stone samples with applied red pigments obtained from an archaeological excavation of an Augustinian friary discovered during the construction of an extension to Hull Magistrates Court in 1994 has revealed a surprising diversity of composition. Cinnabar, red lead and haematite have all been identified alone or in admixture; the cinnabar is exceptional in that it has only been found heavily adulterated with red ochre and red lead, as the other two pigments are found alone. There are signatures of limewash putty, which has been applied to the stone substrate prior to the painting, which is characteristic of the Roman method of wall painting, and there are no traces of gypsum found in the specimens studied. This evidence indicates an early mediaeval method of stone decoration.

  5. A Peltier cooling diamond anvil cell for low-temperature Raman spectroscopic measurements

    Science.gov (United States)

    Noguchi, Naoki; Okuchi, Takuo

    2016-12-01

    A new cooling system using Peltier modules is presented for a low-temperature diamond anvil cell instrument. This cooling system has many advantages: it is vibration-free, low-cost, and compact. It consists of double-stacked Peltier modules and heat sinks, where a cooled ethylene glycol-water mixture flows through a chiller. Current is applied to the Peltier modules by two programmable DC power supplies. Sample temperature can be controlled within the range 210-300 K with a precision of ±0.1 K via a Proportional-Integral-Differential (PID) control loop. A Raman spectroscopic study for the H2O ice VII-VIII transition is shown as an example of an application of the Peltier cooling diamond anvil cell system.

  6. Bacterioruberin and salinixanthin carotenoids of extremely halophilic Archaea and Bacteria: A Raman spectroscopic study

    Science.gov (United States)

    Jehlička, J.; Edwards, H. G. M.; Oren, A.

    2013-04-01

    Laboratory cultures of a number of red extremely halophilic Archaea (Halobacterium salinarum strains NRC-1 and R1, Halorubrum sodomense, Haloarcula valismortis) and of Salinibacter ruber, a red extremely halophilic member of the Bacteria, have been investigated by Raman spectroscopy using 514.5 nm excitation to characterize their carotenoids. The 50-carbon carotenoid α-bacterioruberin was detected as the major carotenoid in all archaeal strains. Raman spectroscopy also detected bacterioruberin as the main pigment in a red pellet of cells collected from a saltern crystallizer pond. Salinibacter contains the C40-carotenoid acyl glycoside salinixanthin (all-E, 2'S)-2'-hydroxy-1'-[6-O-(methyltetradecanoyl)-β-D-glycopyranosyloxy]-3',4'-didehydro-1',2'-dihydro-β,ψ-carotene-4-one), for which the Raman bands assignments of are given here for the first time.

  7. Raman spectroscopic study of a post-medieval wall painting in need of conservation.

    Science.gov (United States)

    Edwards, Howell G M; Farwell, Dennis W; Brooke, Christopher J

    2005-09-01

    Raman spectroscopic studies of four specimens from an important angel wall painting in need of conservation work in a medieval church have provided some information about the pigments and pigment compositions which will influence possible future preservation and restoration strategies. Excitation of the Raman spectra at 1,064 nm in macroscopic mode and at 785 nm in microscopic mode revealed that the white pigment on the angel's wings was a mixture of barytes with calcite and lead white in minor composition. Although the specimens provided were not directly associated with coloured regions of the painting, yellow and blue microcrystals were found and they were identified as chrome yellow and lazurite, respectively. Red and brown particles were identified as cinnabar/vermilion and haematite. Several green particles were also found but could not be identified. The green and blue crystals could be related to neighbouring coloured regions of the artwork and the yellow colour could be identified as a background to the angel figure. Particles of carbon were found to be dispersed throughout the specimens and can be ascribed to soot from candles, heating stoves or oil lamps providing lighting in the church. No evidence for biological deterioration was found from the spectra. The unusual pigment palette is strongly suggestive of a later date of painting than was originally believed but there is a possibility that an earlier rendition exists underneath. Following a review of the spectroscopic data, a more extensive sampling protocol is recommended, from which some stratigraphic evidence could identify the underlying plaster and possible artwork.

  8. Mediaeval cantorals in the Valladolid Biblioteca: FT-Raman spectroscopic study.

    Science.gov (United States)

    Edwards, H G; Farwell, D W; Rull Perez, F; Medina Garcia, J

    2001-03-01

    Raman spectroscopic studies of three mediaeval cantorals in the Biblioteca of the University of Valladolid has revealed information about the pigments used on these large manuscripts. Although executed in a simple colour palette, very pure cinnabar was used as the major colourant, offsetting the carbon black of the verses and script. A dark blue colour was achieved using a mixture of azurite (basic copper carbonate) and carbon, whereas a light blue colour was azurite alone. A grey colour was achieved using azurite, carbon particles and a calcareous 'limewash'. A yellow pigment, used sparely in the cantorals was ascribed to saffron; unusually, there was no evidence for the presence of the yellow mineral pigments orpiment, realgar and massicot. In several regions of the vellum specimens, evidence for biodeterioration was observed through the signatures of hydrated calcium oxalate. We report for the first time the Raman spectra of pigment in situ on a vellum fragment, which also shows evidence of substrate bands; comparison of black and red pigmented regions of vellum specimens has shown the presence of calcium oxalate in the black pigmented script but not in the red pigment regions, which suggests that the cinnabar in the red-pigmented regions acts as a toxic protectant for the vellum substrate against biological colonisation processes.

  9. LED phototherapy on midpalatal suture after rapid maxilla expansion: a Raman spectroscopic study

    Science.gov (United States)

    Rosa, Cristiane B.; Habib, Fernando Antonio L.; de Araújo, Telma M.; dos Santos, Jean N.; Cangussu, Maria Cristina T.; Barbosa, Artur Felipe S.; de Castro, Isabele Cardoso V.; Soares, Luiz Guilherme P.; Pinheiro, Antonio L. B.

    2015-03-01

    A quick bone formation after maxillary expansion would reduce treatment timeand the biomodulating effects of LED light could contribute for it. The aim of this study was to analyze the effect of LED phototherapy on the acceleration of bone formation at the midpalatal suture after maxilla expansion. Thirty rats divided into 6 groups were used on the study at 2 time points - 7 days: Control; Expansion; and Expansion + LED; and 14 days: Expansion; Expansion + LED in the first week; Expansion and LED in the first and second weeks. LED irradiation occurred at every 48 h during 2 weeks. Expansion was accomplished using a spatula and maintained with a triple helicoid of 0.020" stainless steel orthodontic wire. A LED light (λ850 ± 10nm, 150mW ± 10mW, spot of 0.5cm2, t=120 sec, SAEF of 18J/cm2) was applied in one point in the midpalatal suture immediately behind the upper incisors. Near infrared Raman spectroscopic analysis of the suture region was carried and data submitted to statistical analyzes (p≤0.05). Raman spectrum analysis demonstrated that irradiation increased hydroxyapatite in the midpalatal suture after expansion. The results of this indicate that LED irradiation; have a positive biomodulation contributing to the acceleration of bone formation in the midpalatal suture after expansion procedure.

  10. Analytical Raman spectroscopic study for discriminant analysis of different animal-derived feedstuff: Understanding the high correlation between Raman spectroscopy and lipid characteristics.

    Science.gov (United States)

    Gao, Fei; Xu, Lingzhi; Zhang, Yuejing; Yang, Zengling; Han, Lujia; Liu, Xian

    2018-02-01

    The objectives of the current study were to explore the correlation between Raman spectroscopy and lipid characteristics and to assess the potential of Raman spectroscopic methods for distinguishing the different sources of animal-originated feed based on lipid characteristics. A total of 105 lipid samples derived from five animal species have been analyzed by gas chromatography (GC) and FT-Raman spectroscopy. High correlations (r 2 >0.94) were found between the characteristic peak ratio of the Raman spectra (1654/1748 and 1654/1445) and the degree of unsaturation of the animal lipids. The results of FT-Raman data combined with chemometrics showed that the fishmeal, poultry, porcine and ruminant (bovine and ovine) MBMs could be well separated based on their lipid spectral characteristics. This study demonstrated that FT-Raman spectroscopy can mostly exhibit the lipid structure specificity of different species of animal-originated feed and can be used to discriminate different animal-originated feed samples. Copyright © 2017. Published by Elsevier Ltd.

  11. Raman Spectroscopic Study of As-Deposited and Exfoliated Defected Graphene Grown on (001 Si Substrates by CVD

    Directory of Open Access Journals (Sweden)

    T. I. Milenov

    2017-01-01

    Full Text Available We present here results on a Raman spectroscopic study of the deposited defected graphene on Si substrates by chemical vapor deposition (thermal decomposition of acetone. The graphene films are not deposited on the (001 Si substrate directly but on two types of interlayers of mixed phases unintentionally deposited on the substrates: а diamond-like carbon (designated here as DLC and amorphous carbon (designated here as αC are dominated ones. The performed thorough Raman spectroscopic study of as-deposited as well as exfoliated specimens by two different techniques using different excitation wavelengths (488, 514, and 613 nm as well as polarized Raman spectroscopy establishes that the composition of the designated DLC layers varies with depth: the initial layers on the Si substrate consist of DLC, nanodiamond species, and C70 fullerenes while the upper ones are dominated by DLC with an occasional presence of C70 fullerenes. The αC interlayer is dominated by turbostratic graphite and contains a larger quantity of C70 than the DLC-designated interlayers. The results of polarized and unpolarized Raman spectroscopic studies of as-grown and exfoliated graphene films tend to assume that single- to three-layered defected graphene is deposited on the interlayers. It can be concluded that the observed slight upshift of the 2D band as well as the broadening of 2D band should be related to the strain and doping.

  12. Statistical investigation of spectroscopic binary stars

    International Nuclear Information System (INIS)

    Tutukov, A.V.; Yungelson, L.R.

    1980-01-01

    A catalog of physical parameters of about 1000 spectroscopic binary stars (SB), based on the Batten catalog, its extensions, and newly published data has been compiled. Masses of stars' components (M 1 and M 2 ), mass ratios of components (q=M 1 /M 2 ) and orbital angular momenta are computed, wherever possible. It is probable that the initial mass function of the primaries is non-monotonic and is described only approximately by a power-law. A number of assumed 'initial' distributions of M 1 , q and the semiaxes of orbits were transformed with the aim of obtaining 'observed' distributions taking into account the observational selection due to the luminosities of the components, their radial velocities, inclinations of the orbits, and the effects of matter exchange between the components. (Auth.)

  13. Spectroscopic investigation of oxidized solder surfaces

    International Nuclear Information System (INIS)

    Song, Jenn-Ming; Chang-Chien, Yu-Chien; Huang, Bo-Chang; Chen, Wei-Ting; Shie, Chi-Rung; Hsu, Chuang-Yao

    2011-01-01

    Highlights: → UV-visible spectroscopy is successfully used to evaluate the degree of discoloring of solders. → The surface oxides of solders can also be identified by UV-visible absorption spectra. → The discoloration of solder surface can be correlated with optical characterization of oxides. → A strategy against discoloring by alloying was also suggested. - Abstract: For further understanding of the discoloration of solder surfaces due to oxidation during the assembly and operation of electronic devices, UV-vis and X-ray photoelectron spectroscopic analyses were applied to evaluate the degree of discoloring and identify the surface oxides. The decrease in reflectance of the oxidized solder surface is related to SnO whose absorption band is located within the visible region. A trace of P can effectively depress the discoloration of solders under both solid and semi-solid states through the suppression of SnO.

  14. Removal of Aqueous Boron by Using Complexation of Boric Acid with Polyols: A Raman Spectroscopic Study

    Energy Technology Data Exchange (ETDEWEB)

    Eom, Ki Heon; Jeong, Hui Cheol; An, Hye Young; Lim, Jun-Heok; Lee, Jea-Keun; Won, Yong Sun [Pukyong National University, Busan (Korea, Republic of)

    2015-12-15

    Boron is difficult to be removed from seawater by simple RO (reverse osmosis) membrane process, because the size of boric acid (B(OH){sub 3}), the major form of aqueous boron, is as small as the nominal pore size of RO membrane. Thus, the complexation of boric acid with polyols was suggested as an alternative way to increase the size of aqueous boron compounds and the complexation behavior was investigated with Raman spectroscopy. As a reference, the Raman peak for symmetric B-O stretching vibrational mode both in boric acid and borate ion (B(OH){sub 4}{sup -}) was selected. A Raman peak shift (877 cm{sup -1} →730 cm{sup -1}) was observed to confirm that boric acid in water is converted to borate ion as the pH increases, which is also correctly predicted by frequency calculation. Meanwhile, the Raman peak of borate ion (730 cm{sup -1}) did not appear as the pH increased when polyols were applied into aqueous solution of boric acid, suggesting that the boric acid forms complexing compounds by combining with polyols.

  15. Raman spectroscopic analysis of gunshot residue offering great potential for caliber differentiation.

    Science.gov (United States)

    Bueno, Justin; Sikirzhytski, Vitali; Lednev, Igor K

    2012-05-15

    Near-infrared (NIR) Raman microspectroscopy combined with advanced statistics was used to differentiate gunshot residue (GSR) particles originating from different caliber ammunition. The firearm discharge process is analogous to a complex chemical reaction. The reagents of this process are represented by the chemical composition of the ammunition, firearm, and cartridge case. The specific firearm parameters determine the conditions of the reaction and thus the subsequent product, GSR. We found that Raman spectra collected from these products are characteristic for different caliber ammunition. GSR particles from 9 mm and 0.38 caliber ammunition, collected under identical discharge conditions, were used to demonstrate the capability of confocal Raman microspectroscopy for the discrimination and identification of GSR particles. The caliber differentiation algorithm is based on support vector machines (SVM) and partial least squares (PLS) discriminant analyses, validated by a leave-one-out cross-validation method. This study demonstrates for the first time that NIR Raman microspectroscopy has the potential for the reagentless differentiation of GSR based upon forensically relevant parameters, such as caliber size. When fully developed, this method should have a significant impact on the efficiency of crime scene investigations.

  16. Molecular structure and spectroscopic properties of 4-nitrocatechol at different pH: UV-visible, Raman, DFT and TD-DFT calculations

    International Nuclear Information System (INIS)

    Cornard, Jean-Paul; Rasmiwetti; Merlin, Jean-Claude

    2005-01-01

    We investigated theoretically, by density functional theoretical calculations and by vibrational and electronic spectroscopies, the structure and the molecular spectroscopic properties of the 4-nitrocatechol molecule with varying pH. The lower energy stable structures of the neutral, monoanion and dianion forms were compared, and influence of water solvation was examined. The Raman and UV-visible spectra of 4-nitrocatechol and of its singly deprotonated form were recorded by varying the pH from 2 to 9. A calculation of the vibrational frequencies has allowed a complete assignment of the Raman spectra of the two forms of 4-nitrocatechol, and has permitted to investigate the evolution of vibrational normal modes upon deprotonation. Based on the molecular orbital analysis and the time dependent DFT (TD-DFT) calculations, we discussed the electronic structure and the assignment of the absorption bands in the electronic spectra of 4-nitrocatechol and mono-deprotonated 4-nitrocatechol

  17. Spectroscopic (FT-IR, FT-Raman and UV-Visible) investigations, NMR chemical shielding anisotropy (CSA) parameters of 2,6-Diamino-4-chloropyrimidine for dye sensitized solar cells using density functional theory.

    Science.gov (United States)

    Gladis Anitha, E; Joseph Vedhagiri, S; Parimala, K

    2015-02-05

    The molecular structure, geometry optimization, vibrational frequencies of organic dye sensitizer 2,6-Diamino-4-chloropyrimidine (DACP) were studied based on Hartree-Fock (HF) and density functional theory (DFT) using B3LYP methods with 6-311++G(d,p) basis set. Ultraviolet-Visible (UV-Vis) spectrum was investigated by time dependent DFT (TD-DFT). Features of the electronic absorption spectrum in the UV-Visible regions were assigned based on TD-DFT calculation. The absorption bands are assigned to transitions. The interfacial electron transfer between semiconductor TiO2 electrode and dye sensitizer DACP is due to an electron injection process from excited dye to the semiconductor's conduction band. The observed and the calculated frequencies are found to be in good agreement. The energies of the frontier molecular orbitals (FMOS) have also been determined. The chemical shielding anisotropic (CSA) parameters are calculated from the NMR analysis, Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Raman scattering investigation of the water-bridge phenomenon: Some preliminary results

    Directory of Open Access Journals (Sweden)

    Francesco Aliotta

    2010-09-01

    Full Text Available A floating water-bridge is formed if a high-voltage direct current is applied between two beakers filled of chemically pure water. Raman spectra of the OH-stretching region have been obtained at ambient condition of temperature and pressure. These preliminary results seem to indicate that the hydrogen-bond structure is only slightly modified by the presence of the electric field applied to form the floating water-bridge in agreement with recent neutron scattering investigation. In fact, the polarized Raman spectrum of the pure water and of the water-bridge is almost superimposable. We are planning to carry out further spectroscopic analysis, at different thermodynamic conditions, for better understanding the role played by the hydrogen-bond in driving the formation of the floating water-bridge.

  19. Temperature and Salinity Effects on Quantitative Raman Spectroscopic Analysis of Dissolved Volatiles Concentration in Geofluids

    Science.gov (United States)

    Wu, X.; Lu, W.

    2017-12-01

    The concentration detection of the volatiles such as CH4 and CO2 in the hydrothermal systems and fluid inclusions is critical for understanding the fluxes of volatiles from mantle to crust and atmosphere. In-situ Raman spectroscopy has been developed successfully in laboratory, fluid inclusions and submarine environment because of its non-destructive and non-contact advantages. For improving the ability of detecting different species quantitatively by in-situ Raman spectroscopy in the extreme environment, such as the hydrothermal system and fluid inclusion, we studied the temperature- and salinity-dependence of Raman scattering cross section (RSCS) of the water OH stretching band at temperatures from 20 to 300 oC under 30 MPa. This is important because the water is often used as internal standard in the Raman quantitative application. Based on our previous study of NaCl-H2O system, we made further investigation on the CaCl2-H2O system. Our results revealed that the cation shows negligible effect on the RSCS of water OH stretching band, while the cations seems to have more obvious different effect on the structure of water within high temperatures. Besides the NaCl-CH4-H2O system, we also take the CO2-H2O system into account. Further conclusion can be made that the variation of the Raman quantitative factor (QF) (both PAR/mCH4 and PAR/mCO2) with the temperature and salinity is mainly caused by the temperature- and Cl- concentration-dependence of the relative RSCS of the water OH stretching band. If the Raman quantitative factor at ambient condition still being used, the RSCS of the water OH stretching band would induce about 47%, 34% and 29% error for the determined concentration of dissolved CH4 or CO2 (in mol/kg·H2O) by in-situ Raman spectroscopy for 0 m Cl-, 3 m Cl- and 5 m Cl- aqueous system when the temperature increases from 20 to 300 oC, respectively. Considering the wide range of the temperature and salinity in hydrothermal systems and fluid inclusions, the

  20. EPR spectroscopic investigation of psoriatic finger nails.

    Science.gov (United States)

    Nakagawa, Kouichi; Minakawa, Satoko; Sawamura, Daisuke

    2013-11-01

    Nail lesions are common features of psoriasis and found in almost half of the patients. However, there is no feasible spectroscopic method evaluating changes and severity of nail psoriasis. EPR (electron paramagnetic resonance) might be feasible for evaluating nail conditions in the patients of psoriasis. Finger nails of five cases with nail psoriasis, (three females and two males) were examined. Nail samples were subjected to the EPR assay. The small piece of the finger nail (1.5 × 5 mm(2)) was incubated in ~50 μM 5-DSA (5-doxylstearic acid) aqueous solutions for about 60 min at 37°C. After rinsing and wiping off the excess 5-DSA solution, the nail samples were measured by EPR. EPR spectra were analyzed using the intensity ratio (Fast/Slow) of the two motions at the peaks of the lower magnetic field. We observed two distinguishable sites on the basis of the EPR results. In addition, the modern EPR calculation was performed to analyze the spectra obtained. The nail psoriasis-related region is 2~3 times higher than that of the control. The present EPR results show that there are two distinguishable sites in the nail. In the case of nail psoriasis, the fragile components are 2~3 times more than those of the control. Thus, the EPR method is thought to be a novel and reliable method of evaluating the nail psoriasis. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Dielectric and FT-Raman spectroscopic approach to molecular identification of breast tumor tissues.

    Science.gov (United States)

    Abd El-Hakam, Rasha; Khalil, Safaa; Mahani, Ragab

    2015-01-01

    FT-Raman spectra and dielectric properties of benign and malignant women breast tissues in vitro were investigated. FT-Raman spectra for the malignant tissues showed a remarkably decrease in the lipid/protein ratio. Dielectric properties of women breast tissues measured in the low frequency range (42-10(6)Hz) were interpreted in spite of electrode polarization effect. Experimental results showed a contrast between the dielectric properties of malignant (Grade II) and benign tissues within the frequency range studied. The permittivity of malignant to normal breast tissue was found to be 160:1 while it could be 1.3:1 for fibrocystic breast tissues. These findings could contribute to distinguish between two breast tissues. The differences in spectral features between benign and malignant tissues may lead to breast cancer detection. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Raman spectroscopic analysis of the carotenoid concentration in egg yolks depending on the feeding and housing conditions of the laying hens.

    Science.gov (United States)

    Hesterberg, Karoline; Schanzer, Sabine; Patzelt, Alexa; Sterry, Wolfram; Fluhr, Joachim W; Meinke, Martina C; Lademann, Jürgen; Darvin, Maxim E

    2012-01-01

    Resonance Raman spectroscopic measurements are suited to analyze the concentration of carotenoid antioxidants in biological samples. Previously, it has been shown that the carotenoid concentration of nutritional egg yolks has a direct influence on the carotenoid content of human skin in vivo. In the present study, resonance Raman spectroscopy was used to analyze the carotenoid concentration in the yolks of hen eggs, which were housed in battery cages or alternatively on free-range grassland. The egg yolks of hens, which had access to grassland, contained approximately double the amount of carotenoid concentration than the egg yolks of hens housed in battery cages (p egg yolks, depending on fodder, housing and weather conditions, were investigated. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. A portable Raman acoustic levitation spectroscopic system for the identification and environmental monitoring of algal cells.

    Science.gov (United States)

    Wood, Bayden R; Heraud, Philip; Stojkovic, Slobodanka; Morrison, Danielle; Beardall, John; McNaughton, Don

    2005-08-01

    We report the coupling of a portable Raman spectrometer to an acoustic levitation device to enable environmental monitoring and the potential taxonomic identification of microalgae. Spectra of living cells were recorded at 785 nm using a fiber-optic probe coupled to a portable Raman spectrometer. The spectra exhibit an excellent signal-to-noise ratio and clearly show bands from chlorophyll a and beta-carotene. Spectra of levitated photobleached microalgae clearly show a reduction in chlorophyll a concentration relative to beta-carotene after 10 min of exposure to a quartz halogen lamp. Spectra recorded from levitated nitrogen-limited cells also show a significant reduction in bands associated with chlorophyll a, as compared to nitrogen-replete cells. To investigate the diagnostic capability of the technique, four species of microalgae were analyzed. Good quality spectra of all four species were obtained showing varying ratios of beta-carotene to chlorophyll. The combination of an acoustic levitation device and a portable Raman spectrometer shows potential as a taxonomic and environmental monitoring tool with direct application to field studies in remote environments.

  4. Scanning angle Raman spectroscopy: Investigation of Raman scatter enhancement techniques for chemical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Matthew W. [Iowa State Univ., Ames, IA (United States)

    2013-01-01

    This thesis outlines advancements in Raman scatter enhancement techniques by applying evanescent fields, standing-waves (waveguides) and surface enhancements to increase the generated mean square electric field, which is directly related to the intensity of Raman scattering. These techniques are accomplished by employing scanning angle Raman spectroscopy and surface enhanced Raman spectroscopy. A 1064 nm multichannel Raman spectrometer is discussed for chemical analysis of lignin. Extending dispersive multichannel Raman spectroscopy to 1064 nm reduces the fluorescence interference that can mask the weaker Raman scattering. Overall, these techniques help address the major obstacles in Raman spectroscopy for chemical analysis, which include the inherently weak Raman cross section and susceptibility to fluorescence interference.

  5. Raman investigation of molybdenum disulfide with different polytypes

    Science.gov (United States)

    Lee, Jae-Ung; Kim, Kangwon; Han, Songhee; Ryu, Gyeong Hee; Lee, Zonghoon; Cheong, Hyeonsik

    The Raman spectra of molybdenum disulfide (MoS2) with different polytypes are investigated. Although 2H-MoS2 is most common in nature, the 3R phase can exist due to a small difference in the formation energy. However, only a few studies are reported for the 3R phase, and most studies have focused on the 2H phase. We found the 2H, 3R and mixed phases of exfoliated few-layer MoS2 from natural molybdenite crystals. The crystal structures of 2H- and 3R-MoS2 are confirmed by the HR-TEM measurements. By using 3 different excitation energies, we compared the Raman spectra of different polytypes in detail. We show that the Raman spectroscopy can be used to identify not only the number of layers but also the polytypes of MoS2.

  6. A pH dependent Raman and surface enhanced Raman spectroscopic studies of citrazinic acid aided by theoretical calculations

    Science.gov (United States)

    Sarkar, Sougata; Chowdhury, Joydeep; Dutta, Soumen; Pal, Tarasankar

    2016-12-01

    A pH dependent normal Raman scattering (NRS) and surface enhanced Raman scattering (SERS) spectral patterns of citrazinic acid (CZA), a biologically important molecule, have been investigated. The acid, with different pKa values ( 4 and 11) for the two different functional groups (-COOH and -OH groups), shows interesting range of color changes (yellow at pH 14 and brown at pH 2) with the variation in solution pH. Thus, depending upon the pH of the medium, CZA molecule can exist in various protonated and/or deprotonated forms. Here we have prescribed the existence different possible forms of CZA at different pH (Forms ;C;, ;H; and ;Dprot; at pH 14 and Forms ;A;, ;D;, and ;P; at pH 2 respectively). The NRS spectra of these solutions and their respective SERS spectra over gold nanoparticles were recorded. The spectra clearly differ in their spectral profiles. For example the SERS spectra recorded with the CZA solution at pH 2 shows blue shift for different bands compared to its NRS window e.g. 406 to 450 cm- 1, 616 to 632 cm- 1, 1332 to 1343 cm- 1 etc. Again, the most enhanced peak at 1548 cm- 1 in NRS while in the SERS window this appears at 1580 cm- 1. Similar observation was also made for CZA at pH 14. For example, the 423 cm- 1 band in the NRS profile experience a blue shift and appears at 447 cm- 1 in the SERS spectrum as well as other bands at 850, 1067 and 1214 cm- 1 in the SERS window are markedly enhanced. It is also worth noting that the SERS spectra at the different pH also differ from each other. These spectral differences indicate the existence of various adsorptive forms of the CZA molecule depending upon the pH of the solution. Therefore based on the experimental findings we propose different possible molecular forms of CZA at different pH (acidic and alkaline) conditions. For example forms 'A', 'D' and 'P' existing in acidic pH (pH 2) and three other deprotonated forms 'C', 'H' and 'Dprot' in alkaline pH (pH 14). The DFT calculations for these

  7. Spectroscopic investigations of polymorphism of alcohols

    International Nuclear Information System (INIS)

    Sciesinska, E.

    1991-01-01

    The paper presents absorption spectroscopy investigations of polymorphism of four alcohols: cyclopentanol, cyclohexanol, cycloheptanol and t-butanol in the mid infrared range. The study of cyclohexanol is more extended and included some neutron scattering and adiabatic calorimetry results. Multiplet structures of the low frequency skeletal modes (of the CO bending modes in particular) together with the lattice range modes were used to determine the hydrogen bond configurations for the low temperature ordered phases of those alcohols. In the case of cyclopentanol and cycloheptanol it was found also that all their phases are of linear polymer type. The differences between those phases are related to the symmetry of polymers and the stiffness of hydrogen bonding as well as to conformational and orientational order or disorder of molecules. However cyclohexanol and t-butanol both show linear and cyclic polymer phases. The most important finding of this work is that the ordered crystal phases of the studied cyclic alcohols contain two different conformations of the molecules. This new class of molecular crystals is called the conformationally mixed crystals class. A particular multiplet structure of OH (OD) torsion bands of the studied alcohols founds for the ordered linear polymer phases is the other important results of the paper. (author). 181 refs, 26 figs, 15 tab

  8. Raman spectroscopic analyses of preserved historical specimens of human hair attributed to Robert Stephenson and Sir Isaac Newton.

    Science.gov (United States)

    Edwards, Howell G M; Hassan, Nik F N; Wilson, Andrew S

    2004-10-01

    The Raman spectra of two historical specimens of human hair attributed to the engineer Robert Stephenson and scientist Sir Isaac Newton, preserved in private collections are reported. Comparisons are made with the Raman spectra of modern hair specimens and with hair from archaeological excavations. The hair spectra collected with a laser excitation of 785 nm are of a better quality than those collected using 1064 nm. The historical hair specimens are remarkably well-defined spectroscopically in terms of the amide I vibrational mode and the [small nu](SS), ascribed to a predominantly gauche-gauche-gauche CSSC conformation. The contrast with degraded hair specimens recovered from archaeological excavations is striking. The presence of a weak feature near 2590 cm(-1) in the hair samples attributed to a [small nu](SH) vibration could be indicative of a reduction process operative on the CSSC cystine keratotic linkages and a possible origin of this is bacterial biodegradation identified histologically. This study demonstrates the molecular information available from non-destructive Raman spectroscopic analysis from single hair shafts or small bundles of fibres which complements information available from histological and destructive analytical techniques for rare biological specimens subjected to conservation or curation procedures in museums or private collections.

  9. The biocompatibility of carbon hydroxyapatite/β-glucan composite for bone tissue engineering studied with Raman and FTIR spectroscopic imaging.

    Science.gov (United States)

    Sroka-Bartnicka, Anna; Kimber, James A; Borkowski, Leszek; Pawlowska, Marta; Polkowska, Izabela; Kalisz, Grzegorz; Belcarz, Anna; Jozwiak, Krzysztof; Ginalska, Grazyna; Kazarian, Sergei G

    2015-10-01

    The spectroscopic approaches of FTIR imaging and Raman mapping were applied to the characterisation of a new carbon hydroxyapatite/β-glucan composite developed for bone tissue engineering. The composite is an artificial bone material with an apatite-forming ability for the bone repair process. Rabbit bone samples were tested with an implanted bioactive material for a period of several months. Using spectroscopic and chemometric methods, we were able to determine the presence of amides and phosphates and the distribution of lipid-rich domains in the bone tissue, providing an assessment of the composite's bioactivity. Samples were also imaged in transmission using an infrared microscope combined with a focal plane array detector. CaF2 lenses were also used on the infrared microscope to improve spectral quality by reducing scattering artefacts, improving chemometric analysis. The presence of collagen and lipids at the bone/composite interface confirmed biocompatibility and demonstrate the suitability of FTIR microscopic imaging with lenses in studying these samples. It confirmed that the composite is a very good background for collagen growth and increases collagen maturity with the time of the bone growth process. The results indicate the bioactive and biocompatible properties of this composite and demonstrate how Raman and FTIR spectroscopic imaging have been used as an effective tool for tissue characterisation.

  10. Raman spectroscopic analysis of the responds of desert cyanobacterium Nostoc sp under UV-B radiation

    Science.gov (United States)

    Wang, Gaohong; Hao, Zongjie; Hu, Chunxiang; Liu, Yongding

    Cyanobacteria are renowned for tolerating extremes of desiccation, UV radiation, freezethaw cycles, hypersalinity and oligotrophy, which make them as candidate par excellence for terraforming in extraterrestrial planet. Recently Raman spectrum was applied to study the biochemical information changes in different field of life science. In this study, we investigated the respond of desert cyanobactreium Nostoc sp under UV-B radiation via FT-Raman spectra. It was found that the spectral biomarkers of protectant molecular of UV radiation such as β-carotene and scytonemin were induced by UV-B radiation, but Chlorophyll a content was decreased, and also the photosynthesis activity was inhibited significantly. After light adaptation without UV-B radiation, the Chlorophyll a content and photosynthesis activity returned to high level, butβ-carotene and scytonemin content remained in the cells. Those results indicated that desert Cyanobacteria have good adaptation ability for UV-B radiation and synthesis of protectant molecular may be an effective strategy for its adaptation in evolution.

  11. Surface enhanced Raman spectroscopic studies on aspirin : An experimental and theoretical approach

    Energy Technology Data Exchange (ETDEWEB)

    Premkumar, R.; Premkumar, S.; Parameswari, A.; Mathavan, T.; Benial, A. Milton Franklin, E-mail: miltonfranklin@yahoo.com [Department of Physics, N.M.S.S.V.N College, Madurai-625019, Tamilnadu, India. (India); Rekha, T. N. [PG and Research Department of Physics, Lady Doak College, Madurai-625 002, Tamilnadu, India. (India)

    2016-05-06

    Surface enhanced Raman scattering (SERS) studies on aspirin molecule adsorbed on silver nanoparticles (AgNPs) were investigated by experimental and density functional theory approach. The AgNPs were synthesized by the solution-combustion method and characterized by the X-ray diffraction and high resolution-transmission electron microscopy techniques. The averaged particle size of synthesized AgNPs was calculated as ∼55 nm. The normal Raman spectrum (nRs) and SERS spectrum of the aspirin were recorded. The molecular structure of the aspirin and aspirin adsorbed on silver cluster were optimized by the DFT/ B3PW91 method with LanL2DZ basis set. The vibrational frequencies were calculated and assigned on the basis of potential energy distribution calculation. The calculated nRs and SERS frequencies were correlated well with the observed frequencies. The flat-on orientation was predicted from the nRs and SERS spectra, when the aspirin adsorbed on the AgNPs. Hence, the present studies lead to the understanding of adsorption process of aspirin on the AgNPs, which paves the way for biomedical applications.

  12. Raman spectroscopic study of calcite III to aragonite transformation under high pressure and high temperature

    Science.gov (United States)

    Liu, Chuanjiang; Zheng, Haifei; Wang, Duojun

    2017-10-01

    In our study, a series of Raman experiments on the phase transition of calcite at high pressure and high temperature were investigated using a hydrothermal diamond anvil cell and Raman spectroscopy technique. It was found that calcite I transformed to calcite II and calcite III at pressures of 1.62 and 2.12 GPa and room temperature. With increasing temperature, the phase transition of calcite III to aragonite occurred. Aragonite was retained upon slowly cooling of the system, indicating that the transition of calcite III to aragonite was irreversible. Based on the available data, the phase boundary between calcite III and aragonite was determined by the following relation: P(GPa) = 0.013 × T(°C) + 1.22 (100°C ≤ T ≤ 170°C). It showed that the transition pressure linearly rose with increasing temperature. A better understanding of the stability of calcite III and aragonite is of great importance to further explore the thermodynamic behavior of carbonates and carbon cycling in the mantle.

  13. Surface enhanced Raman spectroscopic studies on aspirin : An experimental and theoretical approach

    International Nuclear Information System (INIS)

    Premkumar, R.; Premkumar, S.; Parameswari, A.; Mathavan, T.; Benial, A. Milton Franklin; Rekha, T. N.

    2016-01-01

    Surface enhanced Raman scattering (SERS) studies on aspirin molecule adsorbed on silver nanoparticles (AgNPs) were investigated by experimental and density functional theory approach. The AgNPs were synthesized by the solution-combustion method and characterized by the X-ray diffraction and high resolution-transmission electron microscopy techniques. The averaged particle size of synthesized AgNPs was calculated as ∼55 nm. The normal Raman spectrum (nRs) and SERS spectrum of the aspirin were recorded. The molecular structure of the aspirin and aspirin adsorbed on silver cluster were optimized by the DFT/ B3PW91 method with LanL2DZ basis set. The vibrational frequencies were calculated and assigned on the basis of potential energy distribution calculation. The calculated nRs and SERS frequencies were correlated well with the observed frequencies. The flat-on orientation was predicted from the nRs and SERS spectra, when the aspirin adsorbed on the AgNPs. Hence, the present studies lead to the understanding of adsorption process of aspirin on the AgNPs, which paves the way for biomedical applications.

  14. Investigation of Ferroelectric Domain Walls by Raman Spectroscopy

    Science.gov (United States)

    Stone, Gregory A.

    investigations on other interfaces such as front, side and bottom surfaces revealed a similar appearance of modes due to distortion of wave fronts and reflection. These surfaces are studied to provide insight into mechanism that give rise to Raman modes typically absent for the particular orientation of the crystal.

  15. Fourier transform Raman spectroscopic characterisation of cells of the plant-associated soil bacterium Azospirillum brasilense Sp7

    Science.gov (United States)

    Kamnev, A. A.; Tarantilis, P. A.; Antonyuk, L. P.; Bespalova, L. A.; Polissiou, M. G.; Colina, M.; Gardiner, P. H. E.; Ignatov, V. V.

    2001-05-01

    Structural and compositional features of bacterial cell samples and of lipopolysaccharide-protein complex isolated from the cell surface of the plant-growth-promoting rhizobacterium Azospirillum brasilense (wild-type strain Sp7) were characterised using Fourier transform (FT) Raman spectroscopy. The structural spectroscopic information obtained is analysed and considered together with analytical data on the content of metal cations (Co 2+, Cu 2+ and Zn 2+) in the bacterial cells grown in a standard medium as well as in the presence of each of the cations (0.2 mM). The latter, being taken up by bacterial cells from the culture medium in significant amounts, were shown to induce certain metabolic changes in the bacterium revealed in FT-Raman spectra, which is discussed from the viewpoint of bacterial response to environmental stresses.

  16. Raman spectroscopic assessment of degree of conversion of bulk-fill resin composites--changes at 24 hours post cure.

    Science.gov (United States)

    Par, M; Gamulin, O; Marovic, D; Klaric, E; Tarle, Z

    2015-01-01

    The aim of this study was to determine degree of conversion (DC) of solid and flowable bulk-fill composites immediately and after 24 hours and investigate the variations of DC at surface and depths up to 4 mm. Eight bulk-fill composites (Tetric EvoCeram Bulk Fill [shades IVA and IVB], Quixfil, X-tra fil, Venus Bulk Fill, X-tra Base, SDR, Filtek Bulk Fill) were investigated, and two conventional composites (GrandioSO, X-Flow) were used as controls. The samples (n = 5) were cured for 20 seconds with irradiance of 1090 mW/cm(2). Raman spectroscopic measurements were made immediately after curing on sample surfaces and after 24 hours of dark storage at surface and at incremental depths up to 4 mm. Mean DC values were compared using repeated measures analysis of variance (ANOVA) and t-test for dependent samples. Surface DC values immediately after curing ranged from 59.1%-71.8%, while the 24-hour postcure values ranged from 71.3%-86.1%. A significant increase of DC was observed 24 hours post cure for all bulk-fill composites, which amounted from 11.3% to 16.9%. Decrease of DC through depths up to 4 mm varied widely among bulk-fill composites and ranged from 2.9% to 19.7%. All bulk-fill composites presented a considerable 24-hour postcure DC increase and clinically acceptable DC at depths up to 4 mm. Conventional control composites were sufficiently cured only up to 2 mm, despite significant postcure polymerization.

  17. Micro-Raman spectroscopic identification of bacterial cells of the genus Staphylococcus and dependence on their cultivation conditions.

    Science.gov (United States)

    Harz, M; Rösch, P; Peschke, K-D; Ronneberger, O; Burkhardt, H; Popp, J

    2005-11-01

    Microbial contamination is not only a medical problem, but also plays a large role in pharmaceutical clean room production and food processing technology. Therefore many techniques were developed to achieve differentiation and identification of microorganisms. Among these methods vibrational spectroscopic techniques (IR, Raman and SERS) are useful tools because of their rapidity and sensitivity. Recently we have shown that micro-Raman spectroscopy in combination with a support vector machine is an extremely capable approach for a fast and reliable, non-destructive online identification of single bacteria belonging to different genera. In order to simulate different environmental conditions we analyzed in this contribution different Staphylococcus strains with varying cultivation conditions in order to evaluate our method with a reliable dataset. First, micro-Raman spectra of the bulk material and single bacterial cells that were grown under the same conditions were recorded and used separately for a distinct chemotaxonomic classification of the strains. Furthermore Raman spectra were recorded from single bacterial cells that were cultured under various conditions to study the influence of cultivation on the discrimination ability. This dataset was analyzed both with a hierarchical cluster analysis (HCA) and a support vector machine (SVM).

  18. Book Review: Reiner Salzer and Heinz W. Siesler (Eds.): Infrared and Raman spectroscopic imaging, 2nd ed

    International Nuclear Information System (INIS)

    Moore, David Steven

    2015-01-01

    This second edition of 'Infrared and Raman Spectroscopic Imaging' propels practitioners in that wide-ranging field, as well as other readers, to the current state of the art in a well-produced and full-color, completely revised and updated, volume. This new edition chronicles the expanded application of vibrational spectroscopic imaging from yesterday's time-consuming point-by-point buildup of a hyperspectral image cube, through the improvements afforded by the addition of focal plane arrays and line scan imaging, to methods applicable beyond the diffraction limit, instructs the reader on the improved instrumentation and image and data analysis methods, and expounds on their application to fundamental biomedical knowledge, food and agricultural surveys, materials science, process and quality control, and many others

  19. Synergistic effects of atmospheric pressure plasma-emitted components on DNA oligomers: a Raman spectroscopic study.

    Science.gov (United States)

    Edengeiser, Eugen; Lackmann, Jan-Wilm; Bründermann, Erik; Schneider, Simon; Benedikt, Jan; Bandow, Julia E; Havenith, Martina

    2015-11-01

    Cold atmospheric-pressure plasmas have become of increasing importance in sterilization processes especially with the growing prevalence of multi-resistant bacteria. Albeit the potential for technological application is obvious, much less is known about the molecular mechanisms underlying bacterial inactivation. X-jet technology separates plasma-generated reactive particles and photons, thus allowing the investigation of their individual and joint effects on DNA. Raman spectroscopy shows that particles and photons cause different modifications in DNA single and double strands. The treatment with the combination of particles and photons does not only result in cumulative, but in synergistic effects. Profilometry confirms that etching is a minor contributor to the observed DNA damage in vitro. Schematics of DNA oligomer treatment with cold atmospheric-pressure plasma. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. High-pressure Raman investigation of the semiconductor antimony oxide

    Energy Technology Data Exchange (ETDEWEB)

    Geng, Aihui; Cao, Lihua [State Key Lab on High Power Semiconductor Laser, Changchun University of Science and Technology, 130022 Changchun (China); Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 130012 Changchun (China); Wan, Chunming [State Key Lab on High Power Semiconductor Laser, Changchun University of Science and Technology, 130022 Changchun (China); Ma, Yanmei [Department of Agronomy, Jilin University, 130062 Changchun (China)

    2011-05-15

    The in situ high-pressure behavior of the semiconductor antimony trioxide (Sb{sub 2}O{sub 3}) has been investigated by Raman spectroscopy techniques in a diamond anvil cell up to 20 GPa at room temperature. New peaks in the external lattice mode range emerged at a pressure above 8.6-15 GPa, suggesting that the structural phase transition occurred. The pressure dependence of Raman frequencies was obtained. The band at 139 cm{sup -1} (assigned to group mode) has a pressure dependence of -0.475 cm{sup -1}/GPa and reveals significant softening at high pressure. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Investigation of the Sensitivity of Transmission Raman Spectroscopy for Polymorph Detection in Pharmaceutical Tablets.

    Science.gov (United States)

    Feng, Hanzhou; Bondi, Robert W; Anderson, Carl A; Drennen, James K; Igne, Benoît

    2017-08-01

    Polymorph detection is critical for ensuring pharmaceutical product quality in drug substances exhibiting polymorphism. Conventional analytical techniques such as X-ray powder diffraction and solid-state nuclear magnetic resonance are utilized primarily for characterizing the presence and identity of specific polymorphs in a sample. These techniques have encountered challenges in analyzing the constitution of polymorphs in the presence of other components commonly found in pharmaceutical dosage forms. Laborious sample preparation procedures are usually required to achieve satisfactory data interpretability. There is a need for alternative techniques capable of probing pharmaceutical dosage forms rapidly and nondestructively, which is dictated by the practical requirements of applications such as quality monitoring on production lines or when quantifying product shelf lifetime. The sensitivity of transmission Raman spectroscopy for detecting polymorphs in final tablet cores was investigated in this work. Carbamazepine was chosen as a model drug, polymorph form III is the commercial form, whereas form I is an undesired polymorph that requires effective detection. The concentration of form I in a direct compression tablet formulation containing 20% w/w of carbamazepine, 74.00% w/w of fillers (mannitol and microcrystalline cellulose), and 6% w/w of croscarmellose sodium, silicon dioxide, and magnesium stearate was estimated using transmission Raman spectroscopy. Quantitative models were generated and optimized using multivariate regression and data preprocessing. Prediction uncertainty was estimated for each validation sample by accounting for all the main variables contributing to the prediction. Multivariate detection limits were calculated based on statistical hypothesis testing. The transmission Raman spectroscopic model had an absolute prediction error of 0.241% w/w for the independent validation set. The method detection limit was estimated at 1.31% w/w. The

  2. Raman spectroscopic studies on single supersaturated droplets of sodium and magnesium acetate.

    Science.gov (United States)

    Wang, Liang-Yu; Zhang, Yun-Hong; Zhao, Li-Jun

    2005-02-03

    Raman spectroscopy was used to study structural changes, in particular, the formation of contact-ion pairs in supersaturated aqueous NaCH(3)COO and Mg(CH(3)COO)(2) droplets at ambient temperatures. The single droplets levitated in an electrodynamic balance (EDB), lost water, and became supersaturated when the relative humidity (RH) decreased. For NaCH(3)COO droplet the water-to-solute molar ratio (WSR) was 3.87 without solidification when water molecules were not enough to fill in the first hydration layer of Na(+), in favor of the formation of contact-ion pairs. However, the symmetric stretching vibration band (nu(3) mode) of free -COO(-) constantly appeared at 1416 cm(-1), and no spectroscopic information related to monodentate, bidentate, or bridge bidentate contact-ion pairs was observed due to the weak interactions between the Na(+) and acetate ion. On the other hand, the band of methyl deformation blue shifted from 1352 to 1370 cm(-1) (at RH = 34.2%, WSR = 2.43), corresponding to the solidification process of a novel metastable phase in the highly supersaturated solutions. With further decreasing RH, a small amount of supersaturated solution still existed and was proposed to be hermetically covered by the metastable phase of the particle. In contrast, the interaction between Mg(2+) and acetate ion is much stronger. When WSR decreased from 21.67 to 2.58 for the Mg(CH(3)COO)(2) droplet, the band of C-C-symmetric stretching (nu(4) mode) had a blue shift from 936 to 947 cm(-1). The intensity of the two new shoulders (approximately 1456 and approximately 1443 cm(-1)) of the nu(3) band of free -COO(-) at 1420 cm(-1) increased with the decrease of WSR. These changes were attributed to the formation of contact-ion pairs with bidentate structures. In particular, the small frequency difference between the shoulder at approximately 1443 cm(-1) and the nu(3) band of the free -COO(-) group (approximately 1420 cm(-1)) was proposed to be related to the formation of a chain

  3. A Raman spectroscopic study of organic matter in interplanetary dust particles and meteorites using multiple wavelength laser excitation

    OpenAIRE

    Starkey, N. A.; Franchi, I. A.; Alexander, C. M. O'D.

    2013-01-01

    Raman spectroscopy was used to investigate insoluble organic matter (IOM) from a range of chondritic meteorites, and a suite of interplanetary dust particles (IDPs). Three monochromatic excitation wavelengths (473 nm, 514 nm, 632 nm) were applied sequentially to assess variations in meteorite and IDP Raman peak parameters (carbon D and G bands) as a function of excitation wavelength (i.e., dispersion). Greatest dispersion occurs in CVs > OCs > CMs > CRs with type 3 chondrites compared at diff...

  4. Raman Spectroscopic Study of the Vapour Phase of 1-Methylimidazolium Ethanoate, a Protic Ionic Liquid

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Canongia Lopes, Jose N.; Ferreira, Rui

    2010-01-01

    The gas phase over the ionic liquid 1-methylimidazolium ethanoate, [Hmim][O2CCH3], was studied by means of Raman spectroscopy. Raman spectra are presented, the species in the gas phase are identified, and their bands are assigned. The results are interpreted using ab initio quantum mechanical...

  5. Infrared and Raman spectroscopic study of ion pairing of strontium(II ...

    African Journals Online (AJOL)

    ABSTRACT. Infrared and Raman spectroscopy techniques have been used to study the ionic interactions of strontium(II) and barium(II) with thiocyanate ion in liquid ammonia. A number of bands were observed in both ν(CN) and ν(CS) regions of infrared and Raman spectra and these were assigned to 1:1 contact ion pair, ...

  6. Using Raman spectroscopic imaging for non-destructive analysis of filler distribution in chalk filled polypropylene

    DEFF Research Database (Denmark)

    Boros, Evelin; Porse, Peter Bak; Nielsen, Inga

    2016-01-01

    A feasibility study on using Raman spectral imaging for visualization and analysis of filler distribution in chalk filled poly-propylene samples has been carried out. The spectral images were acquired using a Raman spectrometer with 785 nm light source.Eight injection-molded samples with concentr...

  7. Raman spectroscopic studies of isotopic diatomic molecules and a technique for measuring stable isotope ratios using Raman scattering

    International Nuclear Information System (INIS)

    Harney, R.C.

    1976-01-01

    A method for measuring stable isotope ratios using Raman scattering has been developed. This method consists of simultaneously counting photons scattered out of a high-intensity laser beam by different isotopically-substituted molecules. A number of studies of isotopic diatomic molecules have been made. The Q-branches of the Raman spectra of the isotopic molecules 14 N 15 N and 16 O 18 O were observed at natural abundance in nitrogen and oxygen samples. Comparison of the ratios of the intensities of the Q-branches of the major nitrogen and oxygen isotopic molecules with mass spectrometric determinations of the isotopic compositions yielded scattering cross sections of 14 N 15 N relative to 14 N 14 N and 16 O 18 O relative to 16 O 16 O. These cross section ratios differ from unity, a difference which can be explained by considering nuclear mass effects on the Franck-Condon factors of the molecular transitions. The measured intensities of the 14 N 15 N and 16 O 18 O Q-branches provided the baseline data needed to make the previously-mentioned extrapolation. High-resolution (approximately 0.15 cm -1 ) spectra of the Q-branches of 14 N 14 N and 16 O 16 O yielded a direct determination of α/sub e/ (the difference between the rotational constant in the ground and first excited vibrational states) for these molecules. The measured values are in excellent agreement with those obtained by other means. Complete Raman spectra (pure rotation, rotation-vibration, and high-resolution Q-branch) were obtained on a sample of pure 18 O 18 O. Analysis of this data yielded the molecular parameters: the equilibrium internuclear separation r/sub e/, the moment of inertia I/sub e/, and the energy parameters α/sub e/, B/sub e/, and ΔG/sub 1 / 2 /. These are in good agreement with data obtained by microwave spectroscopy

  8. A Simple Surface-Enhanced Raman Spectroscopic Method for on-Site Screening of Tetracycline Residue in Whole Milk

    Directory of Open Access Journals (Sweden)

    Sagar Dhakal

    2018-02-01

    Full Text Available Therapeutic and subtherapeutic use of veterinary drugs has increased the risk of residue contamination in animal food products. Antibiotics such as tetracycline are used for mastitis treatment of lactating cows. Milk expressed from treated cows before the withdrawal period has elapsed may contain tetracycline residue. This study developed a simple surface-enhanced Raman spectroscopic (SERS method for on-site screening of tetracycline residue in milk and water. Six batches of silver colloid nanoparticles were prepared for surface enhancement measurement. Milk-tetracycline and water-tetracycline solutions were prepared at seven concentration levels (1000, 500, 100, 10, 1, 0.1, and 0.01 ppm and spiked with silver colloid nanoparticles. A 785 nm Raman spectroscopic system was used for spectral measurement. Tetracycline vibrational modes were observed at 1285, 1317 and 1632 cm−1 in water-tetracycline solutions and 1322 and 1621 cm−1 (shifted from 1317 and 1632 cm−1, respectively in milk-tetracycline solutions. Tetracycline residue concentration as low as 0.01 ppm was detected in both the solutions. The peak intensities at 1285 and 1322 cm−1 were used to estimate the tetracycline concentrations in water and milk with correlation coefficients of 0.92 for water and 0.88 for milk. Results indicate that this SERS method is a potential tool that can be used on-site at field production for qualitative and quantitative detection of tetracycline residues.

  9. A Simple Surface-Enhanced Raman Spectroscopic Method for on-Site Screening of Tetracycline Residue in Whole Milk.

    Science.gov (United States)

    Dhakal, Sagar; Chao, Kuanglin; Huang, Qing; Kim, Moon; Schmidt, Walter; Qin, Jianwei; Broadhurst, C Leigh

    2018-02-01

    Therapeutic and subtherapeutic use of veterinary drugs has increased the risk of residue contamination in animal food products. Antibiotics such as tetracycline are used for mastitis treatment of lactating cows. Milk expressed from treated cows before the withdrawal period has elapsed may contain tetracycline residue. This study developed a simple surface-enhanced Raman spectroscopic (SERS) method for on-site screening of tetracycline residue in milk and water. Six batches of silver colloid nanoparticles were prepared for surface enhancement measurement. Milk-tetracycline and water-tetracycline solutions were prepared at seven concentration levels (1000, 500, 100, 10, 1, 0.1, and 0.01 ppm) and spiked with silver colloid nanoparticles. A 785 nm Raman spectroscopic system was used for spectral measurement. Tetracycline vibrational modes were observed at 1285, 1317 and 1632 cm -1 in water-tetracycline solutions and 1322 and 1621 cm -1 (shifted from 1317 and 1632 cm -1 , respectively) in milk-tetracycline solutions. Tetracycline residue concentration as low as 0.01 ppm was detected in both the solutions. The peak intensities at 1285 and 1322 cm -1 were used to estimate the tetracycline concentrations in water and milk with correlation coefficients of 0.92 for water and 0.88 for milk. Results indicate that this SERS method is a potential tool that can be used on-site at field production for qualitative and quantitative detection of tetracycline residues.

  10. Effect of mechanical stress on the Raman and infrared bands of hydroxylapatite: A quantum mechanical first principle investigation.

    Science.gov (United States)

    Ulian, Gianfranco; Valdrè, Giovanni

    2018-01-01

    The calcium apatite minerals are among the most studied in the biomaterial field because of their similarity with the mineral phase of bone tissues, which is mainly the hexagonal polymorph of hydroxylapatite. Given the growing interest both in the microscopic processes governing the behaviour of these natural biomaterials and in recent experimental methods to investigate the Raman response of hydroxylapatite upon mechanical loading, we report in the present work a detailed quantum mechanical analysis by DFT/B3LYP-D* approach on the Raman and infrared responses of hydroxylapatite upon deformation of its unit cell. From the vibrational results, the piezo-spectroscopic components Δν = Π ij σ ij were calculated. For the first time to the authors' knowledge quantum mechanics (QM) was applied to resolve the piezo-spectroscopic response of hydroxylapatite. The QM results on the uniaxial stress responses of this phase on the piezo-spectroscopic components Π 11 and Π 33 of the symmetric P-O stretching mode were 2.54 ± 0.09cm -1 /GPa and 2.56 ± 0.06cm -1 /GPa, respectively (Raman simulation) and 2.48 ± 0.15cm -1 /GPa and Π 33 = 2.74 ± 0.08cm -1 /GPa, respectively, of the asymmetric P-O stretching (infrared spectroscopy simulation). These results are in excellent agreement with previous experimental data reported in literature. The quantum mechanical analysis of the other vibrational bands (not present in literature) shed more light on this new and very important application of both Raman and IR spectroscopies and extend the knowledge of the behaviour of hydroxylapatite, suggesting and addressing further experimental research and analytic strategy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Quantum-mechanical DFT calculation supported Raman spectroscopic study of some amino acids in bovine insulin.

    Science.gov (United States)

    Tah, Bidisha; Pal, Prabir; Roy, Sourav; Dutta, Debodyuti; Mishra, Sabyashachi; Ghosh, Manash; Talapatra, G B

    2014-08-14

    In this article Quantum mechanical (QM) calculations by Density Functional Theory (DFT) have been performed of all amino acids present in bovine insulin. Simulated Raman spectra of those amino acids are compared with their experimental spectra and the major bands are assigned. The results are in good agreement with experiment. We have also verified the DFT results with Quantum mechanical molecular mechanics (QM/MM) results for some amino acids. QM/MM results are very similar with the DFT results. Although the theoretical calculation of individual amino acids are feasible, but the calculated Raman spectrum of whole protein molecule is difficult or even quite impossible task, since it relies on lengthy and costly quantum-chemical computation. However, we have tried to simulate the Raman spectrum of whole protein by adding the proportionate contribution of the Raman spectra of each amino acid present in this protein. In DFT calculations, only the contributions of disulphide bonds between cysteines are included but the contribution of the peptide and hydrogen bonds have not been considered. We have recorded the Raman spectra of bovine insulin using micro-Raman set up. The experimental spectrum is found to be very similar with the resultant simulated Raman spectrum with some exceptions. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Circumventing substrate interference in the Raman spectroscopic identification of blood stains.

    Science.gov (United States)

    McLaughlin, Gregory; Sikirzhytski, Vitali; Lednev, Igor K

    2013-09-10

    Raman spectroscopy has demonstrated remarkable capabilities in identifying blood in controlled laboratory conditions. However, substrate interference presents a significant challenge toward characterizing body fluid traces with Raman spectroscopy at a crime scene. Here, several possible solutions are explored, including the selection of laser excitation, isolating the signal of blood using spectral subtraction and using a favorable substrate for collection which minimizes interference. Simulated blood stain evidence was prepared and analyzed using a Raman microscope with variable laser capabilities. It is shown that the best approach for detecting blood depends on the nature of the substrate and the type of interference encountered. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  13. A microfluidic surface enhanced Raman spectroscopic biosensor using aptamer functionalized nanopillars

    DEFF Research Database (Denmark)

    Yang, J.; Palla, M.; Bosco, F. G.

    2013-01-01

    This paper presents a microchip incorporating an aptamer-functionalized nanopillar substrate, enabling the specific detection of low-abundance biomolecules using surface enhanced Raman spectroscopy (SERS). In a temperature controlled microchamber, aptamers immobilized on the nanostructure surface...

  14. Combined micro-PIXE and NIR Raman spectroscopic plaque characterisation in a human atherosclerotic aorta sample

    International Nuclear Information System (INIS)

    Brands, P.J.M.; Poll, S.W.E. van de; Quaedackers, J.A.; Mutsaers, P.H.A.; Puppels, G.J.; Laarse, A. van der; Voigt, M.J.A. de

    2001-01-01

    Raman spectroscopy can be applied to characterise the chemical composition of an atherosclerotic plaque in vivo. In the near future this technique may become available for use in (coronary) arteries of living patients. For this moment, Raman spectroscopy is applied on artery samples in vitro, to study progression and regression of atherosclerotic plaque. Raman spectroscopy provides chemical information on a molecular basis. In this study, micro-particle induced X-ray emission (micro-PIXE) is applied to provide additional information on the elemental composition of the artery. Furthermore, the combined techniques allow for validation of the structures studied with Raman spectroscopy. This study proves that it is possible to combine and compare both techniques using the same region on the same sample if proper sample preparation is applied. Comparison shows that regions appearing in the Raman spectroscopy results can also be distinguished in micro-PIXE and backscattering spectroscopy (BS) distributions and vice versa. Combining both techniques makes it possible to separate phospholipids from triglycerides. Combined Raman spectroscopy and micro-PIXE/BS is recommended for studying progression and regression of atherosclerosis

  15. Investigation of silicate mineral sanidine by vibrational and NMR spectroscopic methods

    Science.gov (United States)

    Anbalagan, G.; Sankari, G.; Ponnusamy, S.; kumar, R. Thilak; Gunasekaran, S.

    2009-10-01

    Sanidine, a variety of feldspar minerals has been investigated through optical absorption, vibrational (IR and Raman), EPR and NMR spectroscopic techniques. The principal reflections occurring at the d-spacings, 3.2892, 3.2431, 2.9022 and 2.6041 Å confirm the presence of sanidine structure in the mineral. Sanidine shows five prominent characteristic infrared absorption bands in the region 1200-950, 770-720, 590-540 and 650-640 cm -1. The Raman spectrum shows the strongest band at 512 cm -1 characteristic of the feldspar structure, which contains four membered rings of tetrahedra. The UV-vis-NIR absorption spectrum had strong absorption features at 6757, 5780 and 5181 cm -1 due to the combination of fundamental OH- stretching. The bands at 11236 and 8196 cm -1and the strong, well-defined band at (30303 cm -1 attest the presence of Fe 2+ and Fe 3+, respectively, in the sample. The signals at g = 4.3 and 3.7 are interpreted in terms of Fe 3+ at two distinct tetrahedral positions Tl and T2 of the monoclinic crystal structure The 29Si NMR spectrum shows two peaks at -97 and -101 ppm corresponding to T2 and T1, respectively, and one peak in 27Al NMR for Al(IV).

  16. Raman and FTIR spectroscopic studies on two hydroxylated tung oils (HTO) bearing conjugated double bonds

    Science.gov (United States)

    Zhuang, Yuwei; Ren, Zhiyong; Jiang, Lei; Zhang, Jiaxiang; Wang, Huafen; Zhang, Guobao

    2018-06-01

    Tung oil (TO) was used as a model compound to study two hydroxylated tung oils (HTO), prepared from TO by either aminolysis (HTO-am) or alcoholysis (HTO-al). Main bands in Raman and FTIR spectra were initially assigned based on the detailed analysis of the compound spectra before and after exposure to elevated temperature (200 °C). The effect of heat treatment in air on spectral bands, and especially on the changes associated with double bonds, were then investigated. In the present work, changes in spectral bands due to heat treatment were compared with those revealed in the previous work of others. The results show that the conjugated triene structure of TO has been retained during alcoholysis and aminolysis, to yield the HTOs studied; yet the change of the triene structure caused by heating is different among the three samples; the H-bonding strength between OH and Cdbnd O in HTO-am is higher than that in HTO-al; the changes in HTO vOH and vCdbnd O bands in FTIR caused by the present heat treatment were significant; for TO, there is a big difference between changes in spectra as caused by thermal exposure, compared to those caused by ageing under UV light or exposure to a catalyst. The present work has laid additional groundwork for further study of the reactions of such triply conjugated double bond structures under different ageing conditions.

  17. Development of an in-line Raman spectroscopic method for continuous API quantification during twin-screw wet granulation.

    Science.gov (United States)

    Harting, Julia; Kleinebudde, Peter

    2018-04-01

    Raman spectroscopy was evaluated as a process analytical technology (PAT) tool for continuous API quantification during twin-screw wet granulation. Therefore, a Raman probe was implemented in front of the granulator barrel. This setup enabled the collection of Raman spectra upon a constant granule flow. To develop an in-line PLS calibration model, eight binary mixtures of the API and lactose monohydrate with API contents between 5 and 50% were pre-blended and granulated in a twin-screw granulator with a screw speed of 150 rpm and a powder feed rate of 40 g/min. Water was used as a granulation liquid with different liquid to solid ratios depending on the API content. Ibuprofen and diclofenac sodium were chosen as model drugs and separated PLS models were built for each API. The predictive performance of the developed PLS models was determined by granulating and monitoring new test samples containing different API concentrations. This evaluation showed that the models were able to predict the API concentration with an RMSEP of 0.59% for ibuprofen and 1.5% for diclofenac sodium. In a second part, the developed in-line Raman spectroscopic method was used to determine the API concentration during a split feeding process. Therefore, the API and lactose monohydrate were added by two independently adjustable feeders into the twin-screw granulator barrel. The in-line spectroscopy analysis which was verified by UV-analysis indicated that the mixing ability of the twin-screw granulator was good for the used settings and all adjusted API concentrations. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Sulfates on Mars: A systematic Raman spectroscopic study of hydration states of magnesium sulfates

    Science.gov (United States)

    Wang, A.; Freeman, J.J.; Jolliff, B.L.; Chou, I.-Ming

    2006-01-01

    The martian orbital and landed surface missions, OMEGA on Mar Express and the two Mars Explorations Rovers, respectively, have yielded evidence pointing to the presence of magnesium sulfates on the martian surface. In situ identification of the hydration states of magnesium sulfates, as well as the hydration states of other Ca- and Fe- sulfates, will be crucial in future landed missions on Mars in order to advance our knowledge of the hydrologic history of Mars as well as the potential for hosting life on Mars. Raman spectroscopy is a technique well-suited for landed missions on the martian surface. In this paper, we report a systematic study of the Raman spectra of the hydrates of magnesium sulfate. Characteristic and distinct Raman spectral patterns were observed for each of the 11 distinct hydrates of magnesium sulfates, crystalline and non-crystalline. The unique Raman spectral features along with the general tendency of the shift of the position of the sulfate ??1 band towards higher wavenumbers with a decrease in the degree of hydration allow in situ identification of these hydrated magnesium sulfates from the raw Raman spectra of mixtures. Using these Raman spectral features, we have started the study of the stability field of hydrated magnesium sulfates and the pathways of their transformations at various temperature and relative humidity conditions. In particular we report on the Raman spectrum of an amorphous hydrate of magnesium sulfate (MgSO4??2H2O) that may have specific relevance for the martian surface. ?? 2006 Elsevier Inc. All rights reserved.

  19. Improved removal of blood contamination from ThinPrep cervical cytology samples for Raman spectroscopic analysis.

    Science.gov (United States)

    Traynor, Damien; Duraipandian, Shiyamala; Martin, Cara M; O'Leary, John J; Lyng, Fiona M

    2018-05-01

    There is an unmet need for methods to help in the early detection of cervical precancer. Optical spectroscopy-based techniques, such as Raman spectroscopy, have shown great potential for diagnosis of different cancers, including cervical cancer. However, relatively few studies have been carried out on liquid-based cytology (LBC) pap test specimens and confounding factors, such as blood contamination, have been identified. Previous work reported a method to remove blood contamination before Raman spectroscopy by pretreatment of the slides with hydrogen peroxide. The aim of the present study was to extend this work to excessively bloody samples to see if these could be rendered suitable for Raman spectroscopy. LBC ThinPrep specimens were treated by adding hydrogen peroxide directly to the vial before slide preparation. Good quality Raman spectra were recorded from negative and high grade (HG) cytology samples with no blood contamination and with heavy blood contamination. Good classification between negative and HG cytology could be achieved for samples with no blood contamination (sensitivity 92%, specificity 93%) and heavy blood contamination (sensitivity 89%, specificity 88%) with poorer classification when samples were combined (sensitivity 82%, specificity 87%). This study demonstrates for the first time the improved potential of Raman spectroscopy for analysis of ThinPrep specimens regardless of blood contamination. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  20. Shortwave-infrared Raman spectroscopic classification of water fractions in articular cartilage ex vivo

    Science.gov (United States)

    Unal, Mustafa; Akkus, Ozan

    2018-01-01

    Water loss is an early onset indicator of osteoarthritis. Although Raman spectroscopy (RS) holds the potential for measurement of cartilage hydration, the knowledge of Raman OH-stretch bands of biological tissue is very limited. We assesed here the sensitivity of RS to identify and classify water types in the cartilage. Raman spectrum measurements over the high wavenumber range were employed to identify different water fractions in articular cartilage. Raman spectra were collected from wet and sequentially dehydrated cartilage along with pure collagen type II and chondroitin sulfate standards. OH-stretch band of cartilage is dominated by mobile water, up to 95% of total intensities. We identified six peaks in cartilage spectrum using second-derivative analysis: peaks at 3200 and 3650 cm-1 are associated with organic matrix (both collagen and proteglycan) and matrix-bound water molecules. Peaks at 3250, 3453, and 3630 cm-1 are associated with collagen and collagen-related water molecules, whereas the peak at 3520 cm-1 is associated with proteoglycan (PG) and PG-related water molecules. The current work is the first thorough analysis of the Raman OH-stretch band of the cartilage and with the knowledge generated by this study, it may now be possible to study on cartilage hydration by RS.

  1. Intercalation of hydrotalcites with hexacyanoferrate(II) and (III)-a thermoRaman spectroscopic study

    International Nuclear Information System (INIS)

    Frost, Ray L.; Musumeci, Anthony W.; Bouzaid, Jocelyn; Adebajo, Moses O.; Martens, Wayde N.; Theo Kloprogge, J.

    2005-01-01

    Raman spectroscopy using a hot stage indicates that the intercalation of hexacyanoferrate(II) and (III) in the interlayer space of a Mg, Al hydrotalcites leads to layered solids where the intercalated species is both hexacyanoferrate(II) and (III). Raman spectroscopy shows that depending on the oxidation state of the initial hexacyanoferrate partial oxidation and reduction takes place upon intercalation. For the hexacyanoferrate(III) some partial reduction occurs during synthesis. The symmetry of the hexacyanoferrate decreases from O h existing for the free anions to D 3d in the hexacyanoferrate interlayered hydrotalcite complexes. Hot stage Raman spectroscopy reveals the oxidation of the hexacyanoferrate(II) to hexacyanoferrate(III) in the hydrotalcite interlayer with the removal of the cyanide anions above 250 deg. C. Thermal treatment causes the loss of CN ions through the observation of a band at 2080cm -1 . The hexacyanoferrate (III) interlayered Mg, Al hydrotalcites decomposes above 150 deg. C

  2. Raman spectroscopic study of acute oxidative stress induced changes in mice skeletal muscles

    Science.gov (United States)

    Sriramoju, Vidyasagar; Alimova, Alexandra; Chakraverty, Rahul; Katz, A.; Gayen, S. K.; Larsson, L.; Savage, H. E.; Alfano, R. R.

    2008-02-01

    The oxidative stress due to free radicals is implicated in the pathogenesis of tissue damage in diseases such as muscular dystrophy, Alzheimer dementia, diabetes mellitus, and mitochrondrial myopathies. In this study, the acute oxidative stress induced changes in nicotinamide adenine dinucleotides in mouse skeletal muscles are studied in vitro using Raman spectroscopy. Mammalian skeletal muscles are rich in nicotinamide adenine dinucleotides in both reduced (NADH) and oxidized (NAD) states, as they are sites of aerobic and anaerobic respiration. The relative levels of NAD and NADH are altered in certain physiological and pathological conditions of skeletal muscles. In this study, near infrared Raman spectroscopy is used to identify the molecular fingerprints of NAD and NADH in five-week-old mice biceps femoris muscles. A Raman vibrational mode of NADH is identified in fresh skeletal muscle samples suspended in buffered normal saline. In the same samples, when treated with 1% H IIO II for 5 minutes and 15 minutes, the Raman spectrum shows molecular fingerprints specific to NAD and the disappearance of NADH vibrational bands. The NAD bands after 15 minutes were more intense than after 5 minutes. Since NADH fluoresces and NAD does not, fluorescence spectroscopy is used to confirm the results of the Raman measurements. Fluorescence spectra exhibit an emission peak at 460 nm, corresponding to NADH emission wavelength in fresh muscle samples; while the H IIO II treated muscle samples do not exhibit NADH fluorescence. Raman spectroscopy may be used to develop a minimally invasive, in vivo optical biopsy method to measure the relative NAD and NADH levels in muscle tissues. This may help to detect diseases of muscle, including mitochondrial myopathies and muscular dystrophies.

  3. Native alunogen: A Raman spectroscopic study of a well-described specimen

    Science.gov (United States)

    Košek, Filip; Culka, Adam; Žáček, Vladimír; Laufek, František; Škoda, Radek; Jehlička, Jan

    2018-04-01

    Alunogen (Al2(SO4)3 · 17H2O) is a common secondary mineral in the terrestrial environment (acid mine drainage, volcanic or coal-fire fumaroles), and is also formed through the acidic weathering of aluminosilicates. Moreover, alunogen has been suggested as a part of the Al-bearing deposits on Mars. The identification of alunogen in secondary sulfate mixtures by Raman spectroscopy strictly depends on good knowledge of alunogen spectral features and band positions. However, comprehensive Raman data of alunogen of natural origin are lacking. This study reports on Raman spectra obtained from two natural specimens originating from a burning coal dump at the Schoeller mine, Kladno, Czech Republic, along with the additional characterizations by infrared spectroscopy, X-ray diffraction, and electron microprobe. For comparison purposes, a Raman spectrum of a synthetic analogue was also obtained. The studied specimens have (Al1.99Fe3+0.01)2 (SO4)3·17H2O as their calculated empirical formula, and the structural parameters correspond to the previously reported data for alunogen. Both natural specimens and the synthetic analogue showed uniform Raman spectra with no extensive band splitting in the sulfate vibrational regions. The most intensive Raman band associated with the symmetric stretching vibration of the SO4 tetrahedra (ν1) is located at 992 cm-1. A multicomponent band was observable in the characteristic region for OH-related vibrations. A small variation in the spectral intensity of the hydroxyl bands suggests that the studied specimens could possibly be slightly dehydrated.

  4. Direct identification of on-bead peptides using surface-enhanced Raman spectroscopic barcoding system for high-throughput bioanalysis.

    Science.gov (United States)

    Kang, Homan; Jeong, Sinyoung; Koh, Yul; Geun Cha, Myeong; Yang, Jin-Kyoung; Kyeong, San; Kim, Jaehi; Kwak, Seon-Yeong; Chang, Hye-Jin; Lee, Hyunmi; Jeong, Cheolhwan; Kim, Jong-Ho; Jun, Bong-Hyun; Kim, Yong-Kweon; Hong Jeong, Dae; Lee, Yoon-Sik

    2015-05-28

    Recently, preparation and screening of compound libraries remain one of the most challenging tasks in drug discovery, biomarker detection, and biomolecular profiling processes. So far, several distinct encoding/decoding methods such as chemical encoding, graphical encoding, and optical encoding have been reported to identify those libraries. In this paper, a simple and efficient surface-enhanced Raman spectroscopic (SERS) barcoding method using highly sensitive SERS nanoparticles (SERS ID) is presented. The 44 kinds of SERS IDs were able to generate simple codes and could possibly generate more than one million kinds of codes by incorporating combinations of different SERS IDs. The barcoding method exhibited high stability and reliability under bioassay conditions. The SERS ID encoding based screening platform can identify the peptide ligand on the bead and also quantify its binding affinity for specific protein. We believe that our SERS barcoding technology is a promising method in the screening of one-bead-one-compound (OBOC) libraries for drug discovery.

  5. The spectroscopic (FT-IR, FT-Raman, dispersive Raman and NMR) study of ethyl-6-chloronicotinate molecule by combined density functional theory.

    Science.gov (United States)

    Karabacak, Mehmet; Calisir, Zuhre; Kurt, Mustafa; Kose, Etem; Atac, Ahmet

    2016-01-15

    In this study, ethyl-6-chloronicotinate (E-6-ClN) molecule is recorded in the region 4000-400 cm(-1) and 3500-100 cm(-1) (FT-IR, FT-Raman and dispersive Raman, respectively) in the solid phase. ((1))H and ((13))C nuclear magnetic resonance (NMR) spectra are recorded in DMSO solution. The structural and spectroscopic data of the molecule are obtained for two possible isomers (S1 and S2) from DFT (B3LYP) with 6-311++G(d,p) basis set calculations. The geometry of the molecule is fully optimized, vibrational spectra are calculated and fundamental vibrations are assigned on the basis of the potential energy distribution (PED) of the vibrational modes. ((1))H and ((13))C NMR chemical shifts are calculated by using the gauge-invariant atomic orbital (GIAO) method. The electronic properties, such as excitation energies, oscillator strengths, wavelengths, HOMO and LUMO energies, are performed by time-dependent density functional theory (TD-DFT). Total and partial density of state and overlap population density of state diagrams analysis are presented for E-6-ClN molecule. Furthermore, frontier molecular orbitals (FMO), molecular electrostatic potential, and thermodynamic features are performed. In addition to these, reduced density gradient of the molecule is performed and discussed. As a conclusion, the calculated results are compared with the experimental spectra of the title compound. The results of the calculations are applied to simulate the vibrational spectra of the molecule, which show excellent agreement with the observed ones. The theoretical and tentative results will give us a detailed description of the structural and physicochemical properties of the molecule. Natural bond orbital analysis is done to have more information stability of the molecule arising from charge delocalization, and to reveal the information regarding charge transfer within the molecules. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Raman spectroscopic study on sodium hyaluronate: an effect of proton and gamma irradiation

    Czech Academy of Sciences Publication Activity Database

    Synytsya, A.; Alexa, P.; Wagner, Richard; Davídková, Marie; Volka, K.

    2011-01-01

    Roč. 42, č. 3 (2011), s. 544-550 ISSN 0377-0486 Institutional research plan: CEZ:AV0Z10480505 Keywords : sodium hyaluronate * proton irradiation * gamma irradiation * Raman spectroscopy Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.087, year: 2011 http://onlinelibrary.wiley.com/doi/10.1002/jrs.2724/full

  7. In-situ high-temperature Raman spectroscopic studies of aluminosilicate liquids

    Science.gov (United States)

    Daniel, Isabelle; Gillet, Philippe; Poe, Brent T.; McMillan, Paul F.

    1995-03-01

    We have measured in-situ Raman spectra of aluminosilicate glasses and liquids with albite (NaAlSi3 O8) and anorthite (CaAl2Si2O8) compositions at high temperatures, through their glass transition range up to 1700 and 2000 K, respectively. For these experiments, we have used a wire-loop heating device coupled with micro-Raman spectroscopy, in order to achieve effective spatial filtering of the extraneous thermal radiation. A major concern in this work is the development of methodology for reliably extracting the first and second order contributions to the Raman scattering spectra of aluminosilicate glasses and liquids from the high temperature experimental data, and analyzing these in terms of vibrational (anharmonic) and configurational changes. The changes in the first order Raman spectra with temperature are subtle. The principal low frequency band remains nearly constant with increasing temperature, indicating little change in the T-O-T angle, and that the angle bending vibration is quite harmonic. This is in contrast to vitreous SiO2, studied previously. Above Tg, intensity changes in the 560 590 cm-1 regions of both sets of spectra indicate configurational changes in the supercooled liquids, associated with formation of additional Al-O-Al linkages, or 3-membered (Al, Si)-containing rings. Additional intensity at 800 cm-1 reflects also some rearrangement of the Si-O-Al network.

  8. Diamond/carbon nanotube composites: Raman, FTIR and XPS spectroscopic studies

    Czech Academy of Sciences Publication Activity Database

    Varga, Marián; Ižák, Tibor; Vretenár, V.; Kozak, Halyna; Holovský, Jakub; Artemenko, Anna; Hulman, M.; Skákalová, V.; Lee, D. S.; Kromka, Alexander

    2016-01-01

    Roč. 111, Jan (2016), s. 54-61 ISSN 0008-6223 R&D Projects: GA ČR GC15-22102J; GA MŠk(CZ) 7AMB14SK037 Institutional support: RVO:68378271 Keywords : diamond * carbon nanotubes * spectroscopy * Raman * FTIR * XPS Subject RIV: JI - Composite Materials Impact factor: 6.337, year: 2016

  9. Raman spectroscopic studies of the polymorphism in ZrO2 at high pressures

    International Nuclear Information System (INIS)

    Arashi, H.; Ishigame, M.

    1982-01-01

    The Raman spectra of ZrO 2 at high pressures are measured at room temperature using a diamondanvil pressure-cell. Two kinds of pressure transmitting medium, methanol and NaCl, are used to see the effect of stress components on the phase transformation. The pressure of phase transformation shows a considerable difference between the two media. In the case of methanol, a phase transformation is observed at 3.5 GPa, while in the case of NaCl, at 5.4 GPa. In the high-pressure phase, 19 Raman bands are observed. This number of bands far exceeds that which is expected for the tetragonal phase, D/sub 4h/ 15 in space group. From the relation between the number of Raman bands and the crystal structure, it is more reasonable to consider that the high-pressure phase belongs to a orthorhombic system. The space group of the high-pressure phase is discussed on the basis of the observed number of Raman bands. (author)

  10. Laser Raman Spectroscopic Characterization of Shocked Plagioclase from the Lonar Impact Crater, India.

    Science.gov (United States)

    Chakrabarti, R.; Basu, A. R.; Peterson, J.; Misra, S.

    2004-12-01

    We report Raman spectra of shocked plagioclase grains from the Lonar impact Crater of India. The Lonar Crater, located in the Buldana district of Maharashtra, India (19° 58'N, 76° 31'E), is an almost circular depression in the 65Ma old basalt flows of the Deccan Traps. Age estimates of this impact crater range from 10-50ka. Tektite and basalt samples were collected for this study from the rim of the crater, which is raised about 20 meters above the surrounding plains. For comparison, a Manicouagan maskelynite and an unaltered mid-oceanic ridge basalt with plagioclase laths were also analyzed. Polished thin sections of all these samples were first petrographically studied. The MORB plagioglase as well as the plagioclase from Lonar host-basalts show first order interference colors and distinct multiple lamellar twinning. The Manicouagan maskelynite is isotropic under crossed-polars. The Lonar tektite samples characteristically demonstrate spherules which are identified by their perfectly circular cross-section and isotropic nature. The spherules also contain fragments of the host basalt with plagioclase laths showing lamellar twinning. The groundmass within the spherules shows lath shaped plagioclase grains, most of which show varying degrees of isotropism due to maskelynitization. Raman scattering measurements were performed using the 514.5 nm line of an argon ion laser at an intensity of 40 kW/cm2. An inverted microscope (Nikon TE3000) with 50x objective (NA 0.55) was used for confocal imaging. A holographic notch filter removed residual laser scatter and the Raman scattering was detected by a silicon CCD at -90° C (Princeton Instruments Spec10-400R). Raman spectra were collected from ~250 cm-1 through 2000 cm-1. Raman spectra of crystalline unshocked plagioclase feldspars from the MORB and the Lonar host basalt show strongest peaks at 265 cm-1, 410 cm-1, 510 cm-1 and 1110 cm-1. The results remain the same for different points in a single grain but vary slightly

  11. Raman Spectroscopic Signature Markers of Dopamine-Human Dopamine Transporter Interaction in Living Cells.

    Science.gov (United States)

    Silwal, Achut P; Yadav, Rajeev; Sprague, Jon E; Lu, H Peter

    2017-07-19

    Dopamine (DA) controls many psychological and behavioral activities in the central nervous system (CNS) through interactions with the human dopamine transporter (hDAT) and dopamine receptors. The roles of DA in the function of the CNS are affected by the targeted binding of drugs to hDAT; thus, hDAT plays a critical role in neurophysiology and neuropathophysiology. An effective experimental method is necessary to study the DA-hDAT interaction and effects of variety of drugs like psychostimulants and antidepressants that are dependent on this interaction. In searching for obtaining and identifying the Raman spectral signatures, we have used surface enhanced Raman scattering (SERS) spectroscopy to record SERS spectra from DA, human embryonic kidney 293 cells (HEK293), hDAT-HEK293, DA-HEK293, and DA-hDAT-HEK293. We have demonstrated a specific 2D-distribution SERS spectral analytical approach to analyze DA-hDAT interaction. Our study shows that the Raman modes at 807, 839, 1076, 1090, 1538, and 1665 cm -1 are related to DA-hDAT interaction, where Raman shifts at 807 and 1076 cm -1 are the signature markers for the bound state of DA to probe DA-hDAT interaction. On the basis of density function theory (DFT) calculation, Raman shift of the bound state of DA at 807 cm -1 is related to combination of bending modes α(C3-O10-H21), α(C2-O11-H22), α(C7-C8-H18), α(C6-C4-H13), α(C7-C8-H19), and α(C7-C8-N9), and Raman shift at 1076 cm -1 is related to combination of bending modes α(H19-N9-C8), γ(N9-H19), γ(C8-H19), γ(N9-H20), γ(C8-H18), and α(C7-C8-H18). These findings demonstrate that protein-ligand interactions can be confirmed by probing change in Raman shift of ligand molecules, which could be crucial to understanding molecular interactions between neurotransmitters and their receptors or transporters.

  12. Overview of recent and current spectroscopic investigations with hydrogen isotopologues for KATRIN

    Energy Technology Data Exchange (ETDEWEB)

    Brunst, Tim; Mirz, Sebastian; Groessle, Robin; Krasch, Bennet [Karlsruhe Institute of Technology KIT (Germany). Institute for Technical Physics (ITEP), Tritium Laboratory Karlsruhe (TLK); Collaboration: KATRIN-Collaboration

    2016-07-01

    The Karlsruhe Tritium Neutrino Experiment (KATRIN) investigates the energy spectrum of the tritium β decay near its energetic endpoint in order to determine the electron anti-neutrino mass with a sensitivity of 200 meV/c{sup 2} (90 % C.L.). Therefore, molecular tritium gas is decaying in a windowless gaseous tritium source (WGTS). The physical properties of the gas in the WGTS, like composition, ortho/para ratio or rotational population, need to be stabilised on a 10{sup -3} level due to their direct impact on the initial state distribution of the investigated β decay. In order to obtain a complete model of the molecular processes in the sample various spectroscopic measurements of mixtures with non-radioactive isotopologues (H{sub 2},HD,D{sub 2}) have been using IR spectroscopy in the liquid at temperatures <25 K and Raman spectroscopy in the gaseous phase at room temperature. This poster presents an overview of recent and current investigations with TApIR: The investigation of dimer and cluster formation under KATRIN conditions, as well as the ongoing task to investigate mixtures beyond the thermal equilibrium with highly concentrated HD and the design of a tritium compatible system for temperatures between (15-293) K.

  13. Lichen biomarkers upon heating: a Raman spectroscopic study with implications for extra-terrestrial exploration

    Science.gov (United States)

    Miralles, I.; Capel Ferrón, C.; Hernández, V.; López-Navarrete, J. T.; Jorge-Villar, S. E.

    2017-01-01

    Lithopanspermia Theory has suggested that life was transferred among planets by meteorites and other rocky bodies. If the planet had an atmosphere, this transfer of life had to survive drastic temperature changes in a very short time in its entry or exit. Only organisms able to endure such a temperature range could colonize a planet from outer space. Many experiments are being carried out by NASA and European Space Agency to understand which organisms were able to survive and how. Among the suite of instruments designed for extraplanetary exploration, particularly for Mars surface exploration, a Raman spectrometer was selected with the main objective of looking for life signals. Among all attributes, Raman spectroscopy is able to identify organic and inorganic compounds, either pure or in admixture, without requiring sample manipulation. In this study, we used Raman spectroscopy to examine the lichen Squamarina lentigera biomarkers. We analyse spectral signature changes after sample heating under different experimental situations, such as (a) laser, (b) analysis accumulations over the same spot and (c) environmental temperature increase. Our goal is to evaluate the capability of Raman spectroscopy to identify unambiguously life markers even if heating has induced spectral changes, reflecting biomolecular transformations. Usnic acid, chlorophyll, carotene and calcium oxalates were identified by the Raman spectra. From our experiments, we have seen that usnic acid, carotene and calcium oxalates (the last two have been suggested to be good biomarkers) respond in a different way to environmental heating. Our main conclusion is that despite their abundance in nature or their inorganic composition the resistance to heat makes some molecules more suitable than others as biomarkers.

  14. ESR spectroscopic investigations of the radiation-grafting of fluoropolymers

    Energy Technology Data Exchange (ETDEWEB)

    Huebner, G; Roduner, E [University of Stuttgart (Germany); Brack, H P; Scherer, G G [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    ESR spectroscopic investigations have clarified the influence of several preparative parameters on the reaction rates and yields obtained in the radiation-grafting method used at PSI to prepare proton-conducting polymer membranes. At a given irradiation dose, a higher concentration of reactive radical sites was detected in ETFE films than in FEP films. This higher concentration explains the higher grafting levels and rates of the ETFE films found in our previous grafting experiments. Taken together, the in-situ ESR experiments and grafting experiments show that the rates of disappearance of radical species and grafting rates and final grafting levels depend strongly on the reaction temperature and the oxygen content of the system. Average grafted chain lengths were calculated to contain about 1,000 monomer units. (author) 2 figs., 4 refs.

  15. Spectroscopic investigation of degradation of rapseed oil methyl esters

    International Nuclear Information System (INIS)

    Kampars, V.

    2003-01-01

    Investigation of rapseed oil methyl esters by US VIS and FTIR spectroscopy during the heating at 80 deg C were carried out. The degradation begins immediately after beginning of experiment. The main process at first stage is destroying of carotenoids and oxidation of polyunsaturated fatty acids by forming conjugated polyenes. Between the formation of conjugated triens and destroying of carotenoids exist definite interconnection, but there isn't evidence for the protective activity of carotenoids. As follows from FTIR spectroscopy the increase of carbonyl compounds concentration begins immediately after the start of experiment and continues all the time. Despite to the complex character the peak at 220 nm is only one spectroscopic characteristic with a sharp alteration point and may be used for the fast and simple detection of storage stability of bio diesels. (authors)

  16. The first in situ micro-Raman spectroscopic analysis of prehistoric cave art of Rouffignac St-Cernin, France

    International Nuclear Information System (INIS)

    Lahlil, Sophia; Lebon, Matthieu; Beck, Lucile; Rousseliere, Helene; Vignaud, Colette; Reiche, Ina; Menu, Michel; Paillet, Patrick; Plassard, Frederic

    2012-01-01

    The first in situ micro-Raman spectroscopic study of prehistoric drawings found in the cave of Rouffignac-Saint-Cernin (Dordogne, France) was carried out. Rouffignac cave art, assigned to the upper Magdalenian Paleolithic period (13500-12000 bp), is constituted of more than 250 drawings and engraving including 158 mammoths. There are about a hundred drawings, all made of black pigments. Until now, destructive chemical analyses performed on one sample, as well as recent micro X-ray fluorescence (μ-XRF) in situ analyses have shown that the drawings contain manganese oxides. Because no carbon has yet been found, no direct dating of the drawings could be performed. This new study of the Rouffignac cave using non-destructive in situ micro-analyses aims at confirming or not the absence of carbon-based drawings and at understanding the apparent homogeneity of the parietal representations by the identification of the crystalline phases constituting the black pigments. The adaptability of portable equipment as well as the feasibility of in situ micro-Raman analyses in a cave environment was tested. The results obtained are compared with in situ XRF, and X-ray diffraction microanalysis is performed at the same time in the cave. We demonstrate that a portable Raman instrument is very useful to analyze non-destructively drawings in the following difficult conditions: high humidity, various wall geometries, and small amounts of material studied. These results show that the black manganese oxides romanechite and pyrolusite were used as pigments by prehistorical artists. Carbon and carotenoids have been found locally. Differences between the various figures are highlighted and hypotheses about the drawings production are proposed. (authors)

  17. Thermal stability and hot-stage Raman spectroscopic study of Ca-montmorillonite modified with different surfactants: A comparative study

    International Nuclear Information System (INIS)

    Sun, Zhiming; Park, Yuri; Zheng, Shuilin; Ayoko, Godwin A.; Frost, Ray L.

    2013-01-01

    Highlights: • A typical Ca-montmorillonite was modified with three surfactants through ion exchange. • The organoclays were characterized by XRD, TG and hot stage Raman. • The structural geometry and thermal properties of organoclays were analyzed. • The prepared organoclays show potential prospects in the environmental remediation. - Abstract: Three long chain cationic surfactants were intercalated into Ca-montmorillonite through ion exchange and the obtained organoclays were characterized by X-ray diffraction (XRD), high resolution thermogravimetric analysis (TG) and Raman spectroscopy. The intercalation of surfactants not only changes the surface properties of clay from hydrophilic to hydrophobic but also greatly increases the basal spacing of the interlayers based on XRD analysis. The thermal stability of organoclays intercalated with three surfactants (TTAB, DTAB and CTAB) and the different arrangements of the surfactant molecules intercalated into Ca-montmorillonite were determined by TG-DTG analysis. A Raman spectroscopic study on the Ca-montmorillonite modified by three surfactants prepared at different concentrations provided the detailed conformational ordering of different intercalated long-chain surfactants under different conditions. The wavenumber of the antisymmetric stretching mode is more sensitive than that of the symmetric stretching mode to the mobility of the tail of the amine chain. At room temperature, the conformational ordering is more easily affected by the packing density in the lateral model. With the increase of the temperature, the positions of both the antisymmetric and symmetric stretching bands shift to higher wavenumbers, which indicates a decrease of conformational ordering. This study offers new insights into the structure and properties of Ca-montmorillonite modified with different long chain surfactants. Moreover, the experimental results confirm the potential applications of organic Ca-montmorillonites for the removal

  18. Continuous statistical modelling for rapid detection of adulteration of extra virgin olive oil using mid infrared and Raman spectroscopic data.

    Science.gov (United States)

    Georgouli, Konstantia; Martinez Del Rincon, Jesus; Koidis, Anastasios

    2017-02-15

    The main objective of this work was to develop a novel dimensionality reduction technique as a part of an integrated pattern recognition solution capable of identifying adulterants such as hazelnut oil in extra virgin olive oil at low percentages based on spectroscopic chemical fingerprints. A novel Continuous Locality Preserving Projections (CLPP) technique is proposed which allows the modelling of the continuous nature of the produced in-house admixtures as data series instead of discrete points. The maintenance of the continuous structure of the data manifold enables the better visualisation of this examined classification problem and facilitates the more accurate utilisation of the manifold for detecting the adulterants. The performance of the proposed technique is validated with two different spectroscopic techniques (Raman and Fourier transform infrared, FT-IR). In all cases studied, CLPP accompanied by k-Nearest Neighbors (kNN) algorithm was found to outperform any other state-of-the-art pattern recognition techniques. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Investigating Nanoscale Electrochemistry with Surface- and Tip-Enhanced Raman Spectroscopy.

    Science.gov (United States)

    Zaleski, Stephanie; Wilson, Andrew J; Mattei, Michael; Chen, Xu; Goubert, Guillaume; Cardinal, M Fernanda; Willets, Katherine A; Van Duyne, Richard P

    2016-09-20

    The chemical sensitivity of surface-enhanced Raman spectroscopy (SERS) methodologies allows for the investigation of heterogeneous chemical reactions with high sensitivity. Specifically, SERS methodologies are well-suited to study electron transfer (ET) reactions, which lie at the heart of numerous fundamental processes: electrocatalysis, solar energy conversion, energy storage in batteries, and biological events such as photosynthesis. Heterogeneous ET reactions are commonly monitored by electrochemical methods such as cyclic voltammetry, observing billions of electrochemical events per second. Since the first proof of detecting single molecules by redox cycling, there has been growing interest in examining electrochemistry at the nanoscale and single-molecule levels. Doing so unravels details that would otherwise be obscured by an ensemble experiment. The use of optical spectroscopies, such as SERS, to elucidate nanoscale electrochemical behavior is an attractive alternative to traditional approaches such as scanning electrochemical microscopy (SECM). While techniques such as single-molecule fluorescence or electrogenerated chemiluminescence have been used to optically monitor electrochemical events, SERS methodologies, in particular, have shown great promise for exploring electrochemistry at the nanoscale. SERS is ideally suited to study nanoscale electrochemistry because the Raman-enhancing metallic, nanoscale substrate duly serves as the working electrode material. Moreover, SERS has the ability to directly probe single molecules without redox cycling and can achieve nanoscale spatial resolution in combination with super-resolution or scanning probe microscopies. This Account summarizes the latest progress from the Van Duyne and Willets groups toward understanding nanoelectrochemistry using Raman spectroscopic methodologies. The first half of this Account highlights three techniques that have been recently used to probe few- or single-molecule electrochemical

  20. Raman spectroscopic studies of Nd{sub 0.75}Sm{sub 0.25}GaO{sub 3} single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Nithya, R., E-mail: nithya@igcar.gov.in; Ravindran, T. R. [Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, TN (India); Daniel, D. J. [Centre for Crystal Growth, SSN College of Engineering, Kalavakkam-603110, TN (India)

    2015-06-24

    Single crystals of Nd{sub 1-x}Sm{sub x}GaO{sub 3} (x= 0 and 0.25) were grown by a four mirror IR image furnace using floating zone technique. The crystals are characterized by X-ray diffraction and Raman spectroscopic measurements. NGO adopts orthorhombic structure with Pbnm symmetry and samarium substituted compound also exhibited the same structure as that of the pristine compound without secondary phases. Polarized Raman spectra are measured at ambient temperature in a back scattering geometry. Spectra exhibit low intensity first-order Raman bands. In addition, several high intensity second-order Raman bands have been observed in the frequency range 2000 to 4000 cm{sup −1}.

  1. Raman spectroscopic characterization of CH4 density over a wide range of temperature and pressure

    Science.gov (United States)

    Shang, Linbo; Chou, I-Ming; Burruss, Robert; Hu, Ruizhong; Bi, Xianwu

    2014-01-01

    The positions of the CH4 Raman ν1 symmetric stretching bands were measured in a wide range of temperature (from −180 °C to 350 °C) and density (up to 0.45 g/cm3) using high-pressure optical cell and fused silica capillary capsule. The results show that the Raman band shift is a function of both methane density and temperature; the band shifts to lower wavenumbers as the density increases and the temperature decreases. An equation representing the observed relationship among the CH4 ν1 band position, temperature, and density can be used to calculate the density in natural or synthetic CH4-bearing inclusions.

  2. Surface-enhanced raman spectroscopic studies of ellagic acid in silver colloids

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Jang; Cheong, Byeong Seo; Cho, Han Gook [Dept. of Chemistry, Incheon National University, Incheon (Korea, Republic of)

    2015-06-15

    Surface-enhanced Raman scattering (SERS) spectroscopy has been applied for the vibrational characterization of ellagic acid (EA), a natural organic dye, using citrate-reduced silver colloids. The infrared and FT-Raman spectra of EA in the solid state were examined for comparison. Spectral assignments of the observed bands were aided by density functional theory (DFT) calculations employing the B3LYP functional. The variations in the SERS spectrum with pH and excitation wavelength were analyzed to gain information on the adsorption- and pH-dependent behaviors of the natural dye on the metal surface. On the basis of the observed spectral features and DFT calculations, the adsorption configuration of EA on the silver metal surface is proposed.

  3. FT-Raman spectroscopic study of calcium-rich and magnesium-rich carbonate minerals.

    Science.gov (United States)

    Edwards, Howell G M; Villar, Susana E Jorge; Jehlicka, Jan; Munshi, Tasnim

    2005-08-01

    Calcium and magnesium carbonates are important minerals found in sedimentary environments. Although sandstones are the most common rock colonized by endolith organisms, the production of calcium and magnesium carbonates is important in survival strategies of organisms and as a source for the removal of oxalate ions. Extremophile organisms in some situations may convert or destroy carbonates of calcium and magnesium, which gives important information about the conditions under which these organisms can survive. The identification on the surface of Mars of 'White Rock' formations, in Juventae Chasma or Sabaea Terra, as possibly carbonate rocks makes the study of these minerals a prerequisite of remote Martian exploration. Here, we show the protocol for the identification by Raman spectroscopy of different calcium and magnesium carbonates and we present a database of relevance in the search for life, extinct or extant, on Mars; this will be useful for the assessment of data obtained from remote, miniaturized Raman spectrometers now proposed for Mars exploration.

  4. Coherent anti-Stokes Raman scattering spectroscope/microscope based on a widely tunable laser source

    Science.gov (United States)

    Dementjev, A.; Gulbinas, V.; Serbenta, A.; Kaucikas, M.; Niaura, G.

    2010-03-01

    We present a coherent anti-Stokes Raman scattering (CARS) microscope based on a robust and simple laser source. A picosecond laser operating in a cavity dumping regime at the 1 MHz repetition rate was used to pump a traveling wave optical parametric generator, which serves as a two-color excitation light source for the CARS microscope. We demonstrate the ability of the presented CARS microscope to measure CARS spectra and images by using several detection schemes.

  5. High wavenumber Raman spectroscopic characterization of normal and oral cancer using blood plasma

    Science.gov (United States)

    Pachaiappan, Rekha; Prakasarao, Aruna; Suresh Kumar, Murugesan; Singaravelu, Ganesan

    2017-02-01

    Blood plasma possesses the biomolecules released from cells/tissues after metabolism and reflects the pathological conditions of the subjects. The analysis of biofluids for disease diagnosis becomes very attractive in the diagnosis of cancers due to the ease in the collection of samples, easy to transport, multiple sampling for regular screening of the disease and being less invasive to the patients. Hence, the intention of this study was to apply near-infrared (NIR) Raman spectroscopy in the high wavenumber (HW) region (2500-3400 cm-1) for the diagnosis of oral malignancy using blood plasma. From the Raman spectra it is observed that the biomolecules protein and lipid played a major role in the discrimination between groups. The diagnostic algorithms based on principal components analysis coupled with linear discriminant analysis (PCA-LDA) with the leave-one-patient-out cross-validation method on HW Raman spectra yielded a promising results in the identification of oral malignancy. The details of results will be discussed.

  6. A Combined Raman Spectroscopic and Thermogravimetric Analysis Study on Oxidation of Coal with Different Ranks

    Directory of Open Access Journals (Sweden)

    Weiqing Zhang

    2015-01-01

    Full Text Available Raman spectroscopy and nonisothermal thermogravimetric analysis (TGA measurements have been reported for different rank coals (lignite, bituminous coal, and anthracite and the relationship between the measurements was examined. It was found that the Raman spectra parameters can be used to characterize structure changes in the different rank coals, such as the band area ratios based on the curve-fitted results. Higher ranked coal was found to have higher values of IGR/IAll and IG+GR/IAll but lower values of ID/I(G+GR, IDL/I(G+GR, IS+SL/I(G+GR, and I(GL+GL'/I(G+GR. The oxidation properties of the coal samples were characterized by the reactivity indexes Tig, T20%, and Tmax from TGA data which were found to correlate well with the band area ratios of IGR/IAll, IG+GR/IAll, and IS+SL/I(G+GR. Based on these correlations, the Raman band area ratios were found to correlate with the oxidation activity of coal providing additional structural information which can be used to understand the changes in the TGA measurements.

  7. High-pressure measuring cell for Raman spectroscopic studies of natural gas

    DEFF Research Database (Denmark)

    Hansen, Susanne Brunsgaard; Berg, Rolf W.; Stenby, Erling Halfdan

    2001-01-01

    A system for obtaining Raman spectra of gases at high pressure has been constructed. In order to ensure that a natural gas sample is totally representative, a high-pressure gas-measuring cell has been developed, built up by stainless steel fittings and a sapphire tube. The design and construction...... of this cell are described. A perfect pressure seal has been demonstrated up to 15.0 MPaA (MPa absolute). The cell has been successfully used to obtain Raman spectra of natural gas samples. Some of these spectra are presented and assigned. The most remarkable observation in the spectra is that it is possible...... to detect hydrogen sulfide at concentrations of 1-3 mg H2S/Nm(3). An attempt to make a quantitative analysis of natural gas by the so-called "ratio method" is presented. In addition to this, the relative normalized differential Raman scattering cross sections for ethane and i-butane molecules at 8.0 MPa...

  8. A Combined Raman Spectroscopic and Thermogravimetric Analysis Study on Oxidation of Coal with Different Ranks.

    Science.gov (United States)

    Zhang, Weiqing; Jiang, Shuguang; Hardacre, Christopher; Goodrich, Peter; Wang, Kai; Shao, Hao; Wu, Zhengyan

    2015-01-01

    Raman spectroscopy and nonisothermal thermogravimetric analysis (TGA) measurements have been reported for different rank coals (lignite, bituminous coal, and anthracite) and the relationship between the measurements was examined. It was found that the Raman spectra parameters can be used to characterize structure changes in the different rank coals, such as the band area ratios based on the curve-fitted results. Higher ranked coal was found to have higher values of I GR/I All and I (G + GR)/I All but lower values of I D/I (G+GR), I DL/I (G+GR), I (S + SL)/I (G+GR), and I (GL+GL')/I (G+GR). The oxidation properties of the coal samples were characterized by the reactivity indexes T ig, T 20%, and T max from TGA data which were found to correlate well with the band area ratios of I GR/I All, I (G + GR)/I All, and I (S + SL)/I (G+GR). Based on these correlations, the Raman band area ratios were found to correlate with the oxidation activity of coal providing additional structural information which can be used to understand the changes in the TGA measurements.

  9. Spectroscopic analysis of 8-hydroxyquinoline derivatives and investigation of its reactive properties by DFT and molecular dynamics simulations

    Science.gov (United States)

    Sureshkumar, B.; Mary, Y. Sheena; Resmi, K. S.; Panicker, C. Yohannan; Armaković, Stevan; Armaković, Sanja J.; Van Alsenoy, C.; Narayana, B.; Suma, S.

    2018-03-01

    Two 8-hydroxyquinoline derivatives, 5,7-dichloro-8-hydroxyquinoline (57DC8HQ) and 5-chloro-7-iodo-8-hydroxy quinoline (5CL7I8HQ) have been investigated in details by means of spectroscopic characterization and computational molecular modelling techniques. FT-IR and FT-Raman experimental spectroscopic approaches have been utilized in order to obtain detailed spectroscopic signatures of title compounds, while DFT calculations have been used in order to visualize and assign vibrations. The computed values of dipole moment, polarizability and hyperpolarizability indicate that the title molecules exhibit NLO properties. The evaluated HOMO and LUMO energies demonstrate the chemical stability of the molecules. NBO analysis is made to study the stability of the molecules arising from hyperconjugative interactions and charge delocalization. DFT calculations have been also used jointly with MD simulations in order to investigate in details global and local reactivity properties of title compounds. Also, molecular docking has been also used in order to investigate affinity of title compounds against decarboxylase inhibitor and quinoline derivatives can be a lead compounds for developing new antiparkinsonian drug.

  10. FT-Raman spectroscopic study of bayerite, boehmite, diaspore and gibbsite

    International Nuclear Information System (INIS)

    Ruan, H.D.; Frost, R.L.; Kloprogge, J.T.

    1998-01-01

    Full text: Bayerite and gibbsite are alumina trihydrate (Al(OH) 3 ). Gibbsite occurs abundantly in nature, usually as a major mineral component in bauxite whereas bayerite is rarely found in nature. Boehmite and diaspore are alumina oxohydroxide (AlOOH) and are two other important minerals in bauxite. The Raman spectra of these four minerals were obtained using a Fourier transform Raman spectrometer operating at 1064 nm. The spectra can be divided into two regions, the low frequency region from 200 to 1200 cm -1 and the hydroxyl stretching region from 3000 to 3700 cm -1 . Bayerite spectrum shows five absorption bands, 3652, 3542, 3449, 3438, and 3421 cm -1 and the gibbsite spectrum shows four strong and sharp absorption bands, 3619, 3523, 3433 and 3363 cm -1 in the hydroxyl stretching region. These values are consistent with those reported by Huneke et al. (1980) and Frost et al. (1999a). Four broad bands, 3426, 3365, 3229 and 2935 cm -1 and three weak bands, 3420, 3216 and 3090 cm -1 are present in this region for diaspore and boehmite. The Raman bands correspond well with the infrared absorption bands at 3620, 3525 cm -1 for gibbsite, 3365 cm -1 for diaspore and 3423, 3096 cm -1 for boehmite (Frost et al., 1999c) and these bands are assigned to be Raman and infrared active. The spectra of bayerite, gibbsite and diaspore are complex while the spectrum of boehmite only illustrates four absorption bands in the low frequency region. Common bands of RT-Raman spectra at 1019, 892, 816, 710, 568, 539, 506, 429, 395, 379, 21, 306, 255 and 242 cm -1 were observed for gibbsite, 1079,1068, 898, 866, 545, 434, 388, 322, 292, 250 and 239 cm -1 for bayerite, 705, 608, 446, 260 and 216 cm -1 for diaspore, and 674, 495 and 360 cm -1 for boehmite. The differences in the vibrational spectra of bayerite, gibbsite, diaspore and boehmite are due to differences in the molecular structure of these minerals. The 705, 446 and 260 cm -1 bands are the most intense in the Raman spectra of

  11. High vacuum tip-enhanced Raman spectroscope based on a scanning tunneling microscope.

    Science.gov (United States)

    Fang, Yurui; Zhang, Zhenglong; Sun, Mengtao

    2016-03-01

    In this paper, we present the construction of a high-vacuum tip-enhanced Raman spectroscopy (HV-TERS) system that allows in situ sample preparation and measurement. A detailed description of the prototype instrument is presented with experimental validation of its use and novel ex situ experimental results using the HV-TERS system. The HV-TERS system includes three chambers held under a 10(-7) Pa vacuum. The three chambers are an analysis chamber, a sample preparation chamber, and a fast loading chamber. The analysis chamber is the core chamber and contains a scanning tunneling microscope (STM) and a Raman detector coupled with a 50 × 0.5 numerical aperture objective. The sample preparation chamber is used to produce single-crystalline metal and sub-monolayer molecular films by molecular beam epitaxy. The fast loading chamber allows ex situ preparation of samples for HV-TERS analysis. Atomic resolution can be achieved by the STM on highly ordered pyrolytic graphite. We demonstrate the measurement of localized temperature using the Stokes and anti-Stokes TERS signals from a monolayer of 1,2-benzenedithiol on a gold film using a gold tip. Additionally, plasmonic catalysis can be monitored label-free at the nanoscale using our device. Moreover, the HV-TERS experiments show simultaneously activated infrared and Raman vibrational modes, Fermi resonance, and some other non-linear effects that are not observed in atmospheric TERS experiments. The high spatial and spectral resolution and pure environment of high vacuum are beneficial for basic surface studies.

  12. High vacuum tip-enhanced Raman spectroscope based on a scanning tunneling microscope

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Yurui [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P. O. Box 603-146, Beijing 100190 (China); Bionanophotonics, Department of Applied Physics, Chalmers University of Technology, Göteborg, SE 41296 (Sweden); Zhang, Zhenglong [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P. O. Box 603-146, Beijing 100190 (China); School of Physics and Information Technology, Shaanxi Normal University, 710062 Xi’an (China); Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, 07745 Jena (Germany); Sun, Mengtao, E-mail: mtsun@iphy.ac.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P. O. Box 603-146, Beijing 100190 (China)

    2016-03-15

    In this paper, we present the construction of a high-vacuum tip-enhanced Raman spectroscopy (HV-TERS) system that allows in situ sample preparation and measurement. A detailed description of the prototype instrument is presented with experimental validation of its use and novel ex situ experimental results using the HV-TERS system. The HV-TERS system includes three chambers held under a 10{sup −7} Pa vacuum. The three chambers are an analysis chamber, a sample preparation chamber, and a fast loading chamber. The analysis chamber is the core chamber and contains a scanning tunneling microscope (STM) and a Raman detector coupled with a 50 × 0.5 numerical aperture objective. The sample preparation chamber is used to produce single-crystalline metal and sub-monolayer molecular films by molecular beam epitaxy. The fast loading chamber allows ex situ preparation of samples for HV-TERS analysis. Atomic resolution can be achieved by the STM on highly ordered pyrolytic graphite. We demonstrate the measurement of localized temperature using the Stokes and anti-Stokes TERS signals from a monolayer of 1,2-benzenedithiol on a gold film using a gold tip. Additionally, plasmonic catalysis can be monitored label-free at the nanoscale using our device. Moreover, the HV-TERS experiments show simultaneously activated infrared and Raman vibrational modes, Fermi resonance, and some other non-linear effects that are not observed in atmospheric TERS experiments. The high spatial and spectral resolution and pure environment of high vacuum are beneficial for basic surface studies.

  13. High Energy Solar Spectroscopic Imager (HESSI) Team Investigations

    Science.gov (United States)

    Emslie, A. Gordon

    1998-01-01

    This report covers activities on the above grant for the period through the end of September 1997. The work originally proposed to be performed under a three-year award was converted at that time to a two-year award for the remainder of the period, and is now funded under award NAGS-4027 through Goddard Space Flight Center. The P.I. is a co-investigator on the High Energy Solar Spectroscopic Imager (HESSI) team, selected as a Small-Class Explorer (SNMX) mission in 1997. He has also been a participant in the Space Physics Roadmap Planning Group. Our research has been strongly influenced by the NASA mission opportunities related to these activities. The report is subdivided into four sections, each dealing with a different aspect of our research within this guiding theme. Personnel involved in this research at UAH include the P.I. and graduate students Michele Montgomery and Amy Winebarger. Much of the work has been carried out in collaboration with investigators at other institutions, as detailed below. Attachment: Laser wakefield acceleration and astrophysical applications.

  14. Microscopic and spectroscopic investigation of an explanted opacified intraocular lens

    Energy Technology Data Exchange (ETDEWEB)

    Simon, V., E-mail: viosimon@phys.ubbcluj.ro [Babeş-Bolyai University, Faculty of Physics and Interdisciplinary Research Institute on Bio-Nano-Sciences, 400084 Cluj-Napoca (Romania); Radu, T.; Vulpoi, A. [Babeş-Bolyai University, Faculty of Physics and Interdisciplinary Research Institute on Bio-Nano-Sciences, 400084 Cluj-Napoca (Romania); Rosca, C. [Optilens Clinic of Ophthalmology, 400604 Cluj-Napoca (Romania); Eniu, D. [Iuliu Haţieganu University of Medicine and Pharmacy, Department of Molecular Sciences, 400349 Cluj-Napoca (Romania)

    2015-01-15

    Highlights: • Changes on intraocular lens (IOL) surface after implantation. • Partial opacification of IOL central area. • Elemental composition on IOL surface prior to and after implantation. • First XPS depth profiling examination of the opacifying deposits. • Cell-mediated hydroxyapatite structuring. - Abstract: The investigated polymethylmethacrylate intraocular lens explanted an year after implantation presented a fine granularity consisting of ring-like grains of about 15 μm in diameter. In order to evidence the changes occurred on intraocular lens relative to morphology, elemental composition and atomic environments, microscopic and spectroscopic analyses were carried out using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), energy-dispersive X-ray (EDS), and X-ray photoelectron (XPS) spectroscopies. The results revealed that the grains contain hydroxyapatite mineral phase. A protein layer covers the lens both in opacified and transparent zones. The amide II band is like in basal epithelial cells. The shape and size of the grains, and the XPS depth profiling results indicate the possibility of a cell-mediated process involving lens epithelial cells which fagocitated apoptotic epithelial cells, and in which the debris derived from cell necrosis were calcified. To the best of our knowledge, this is the first investigation on explanted intraocular lenses using XPS depth profiling in order to examine the inside of the opacifying deposits.

  15. Raman and EPR spectroscopic studies of chromium-doped diamond-like carbon films

    Czech Academy of Sciences Publication Activity Database

    Savchenko, Dariia; Vorlíček, Vladimír; Prokhorov, Andriy; Kalabukhova, E.; Lančok, Ján; Jelínek, Miroslav

    2018-01-01

    Roč. 83, Mar (2018), s. 30-37 ISSN 0925-9635 R&D Projects: GA MŠk(CZ) LO1409; GA MŠk(CZ) LM2015088; GA ČR(CZ) GA15-05864S Institutional support: RVO:68378271 Keywords : EPR * micro-Raman spectroscopy * diamond-like films * carbon-related defects * chromium Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 2.561, year: 2016

  16. Infra-red and Raman spectroscopic studies of infected and affected dentine

    International Nuclear Information System (INIS)

    Aminzadeh, A.; Aminzadeh, A.; Khosravy, K.

    2002-01-01

    Diagnosis of infected and affected dentine is an important factor in clinical restorative treatment of dentine. In this study, the IR and Raman spectra of the sound dentine, infected dentine and affected dentine are reported. The structure of infected dentine and affected dentine has been compared with the sound dentine and hydroxyapatite. It is shown while the infected dentine has lost its structure, the affected dentine has more or less a structure similar to the sound dentine. The molecular structure of collagen remains unchanged in both infected and affected dentine

  17. A Raman spectroscopic study of organic matter in interplanetary dust particles and meteorites using multiple wavelength laser excitation

    Science.gov (United States)

    Starkey, N. A.; Franchi, I. A.; Alexander, C. M. O'd.

    2013-10-01

    Raman spectroscopy was used to investigate insoluble organic matter (IOM) from a range of chondritic meteorites, and a suite of interplanetary dust particles (IDPs). Three monochromatic excitation wavelengths (473 nm, 514 nm, 632 nm) were applied sequentially to assess variations in meteorite and IDP Raman peak parameters (carbon D and G bands) as a function of excitation wavelength (i.e., dispersion). Greatest dispersion occurs in CVs > OCs > CMs > CRs with type 3 chondrites compared at different excitation wavelengths displaying conformable relationships, in contrast to type 2 chondrites. These findings indicate homogeneity in the structural nature of type 3 chondrite IOM, while organic matter (OM) in type 2 chondrites appears to be inherently more heterogeneous. If type 2 and type 3 chondrite IOM shares a common source, then thermal metamorphism may have a homogenizing effect on the originally more heterogeneous OM. IDP Raman G bands fall on an extension of the trend displayed by chondrite IOM, with all IDPs having Raman parameters indicative of very disordered carbon, with almost no overlap with IOM. The dispersion effect displayed by IDPs is most similar to CMs for the G band, but intermediate between CMs and CRs for the D band. The existence of some overlapping Raman features in the IDPs and IOM indicates that their OM may share a common origin, but the IDPs preserve more pristine OM that may have been further disordered by ion irradiation. H, C, and N isotopic data for the IDPs reveal that the disordered carbon in IDPs corresponds with higher δ15N and lower δ13C.

  18. Spectroscopic and structural investigation of undoped and Er{sup 3+} doped hafnium silicate layers

    Energy Technology Data Exchange (ETDEWEB)

    Khomenkova, L., E-mail: khomen@ukr.net [CIMAP CEA/CNRS/ENSICAEN/UCBN, 6 Blvd. Maréchal Juin, 14050 Caen Cedex 4 (France); V. Lashkaryov Institute of Semiconductor Physics at NASU, 41 Pr. Nauky, Kyiv 03028 (Ukraine); An, Y.-T. [CIMAP CEA/CNRS/ENSICAEN/UCBN, 6 Blvd. Maréchal Juin, 14050 Caen Cedex 4 (France); Khomenkov, D. [Taras Shevchenko National University of Kyiv, Faculty of Physics, 4 Pr. Hlushkov, Kyiv 03022 (Ukraine); Portier, X.; Labbé, C.; Gourbilleau, F. [CIMAP CEA/CNRS/ENSICAEN/UCBN, 6 Blvd. Maréchal Juin, 14050 Caen Cedex 4 (France)

    2014-11-15

    This paper demonstrates the functionality of radio-frequency magnetron sputtering for the fabrication of undoped and Er-doped Si-rich-HfO{sub 2} films with specific structural and spectroscopic properties. The effect of post-deposition treatment on film properties was investigated by means of Fourier-transform infrared spectroscopy, Raman scattering and photoluminescence methods, as well as Transmission Electron microscopy. It was observed that annealing treatment at 850–1000 °C causes phase separation process and the formation of HfO{sub 2}, SiO{sub 2} and pure Si phases. This process stimulates also an intense light emission in the 700–950-nm spectral range under broad band excitation. The phase separation mechanism as well as the nature of radiative transitions were discussed. Photoluminescence was ascribed to carrier recombination in silicon clusters and host defects. The appearance of silicon clusters was also confirmed by the comparison of luminescent properties of pure HfO{sub 2}, SiO{sub 2}, Si-rich-HfO{sub 2} and Si-rich-SiO{sub 2} films. Additional argument for Si clusters’ formation was obtained under investigation of Er-doped Si-rich HfO{sub 2} films. These latter demonstrated 1.54-µm Er{sup 3+} luminescence under non-resonant excitation originating from an energy transfer from Si clusters towards Er{sup 3+} ions.

  19. Investigation on Clarified Fruit Juice Composition by Using Visible Light Micro-Raman Spectroscopy

    OpenAIRE

    Camerlingo, Carlo; Zenone, Flora; Delfino, Ines; Diano, Nadia; Mita, Damiano Gustavo; Lepore, Maria

    2007-01-01

    Liquid samples of clarified apple and apricot juices at different production stages were investigated using visible light micro-Raman spectroscopy in order to assess its potential in monitoring fruit juice production. As is well-known, pectin plays a strategic role in the production of clarified juice and the possibility of using Raman for its detection during production was therefore evaluated. The data analysis has enabled the clear identification of pectin. In particular, Raman spectra of ...

  20. Temperature-dependent μ-Raman investigation of struvite crystals.

    Science.gov (United States)

    Prywer, Jolanta; Kasprowicz, D; Runka, T

    2016-04-05

    The effect of temperature on the vibrational properties of struvite crystals grown from silica gels was systematically studied by μ-Raman spectroscopy. The time-dependent Raman spectra recorded in the process of long time annealing of struvite crystal at 353 K do not indicate structural changes in the struvite crystal with the time of annealing. The temperature-dependent Raman spectra recorded in the range 298-423 K reveal a phase transition in struvite at about 368 K. Above this characteristic temperature, some of bands assigned to vibrations of the PO4 and NH4 tetrahedra and water molecules observed in the Raman spectra in low temperatures (orthorhombic phase) change their spectral parameters or disappear, which indicates a transition to a higher symmetry structure of struvite in the range of high temperatures. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Raman spectroscopic identification of size-selected airborne particles for quantitative exposure assessment

    International Nuclear Information System (INIS)

    Steer, Brian; Gorbunov, Boris; Price, Mark C; Podoleanu, Adrian

    2016-01-01

    In this paper we present a method for the quantification of chemically distinguished airborne particulate matter, required for health risk assessment. Rather than simply detecting chemical compounds in a sample, we demonstrate an approach for the quantification of exposure to airborne particles and nanomaterials. In line with increasing concerns over the proliferation of engineered particles we consider detection of synthetically produced ZnO crystals. A multi-stage approach is presented whereby the particles are first aerodynamically size segregated from a lab-generated single component aerosol in an impaction sampler. These size fractionated samples are subsequently analysed by Raman spectroscopy. Imaging analysis is applied to Raman spatial maps to provide chemically specific quantification of airborne exposure against background which is critical for health risk evaluation of exposure to airborne particles. Here we present a first proof-of-concept study of the methodology utilising particles in the 2–4 μm aerodynamic diameter range to allow for validation of the approach by comparison to optical microscopy. The results show that the combination of these techniques provides independent size and chemical discrimination of particles. Thereby a method is provided to allow quantitative and chemically distinguished measurements of aerosol concentrations separated into exposure relevant size fractions. (paper)

  2. Infrared and laser-Raman spectroscopic studies of thermally-induced globular protein gels.

    Science.gov (United States)

    Clark, A H; Saunderson, D H; Suggett, A

    1981-03-01

    Infrared and laser-Raman spectroscopy have been used to follow secondary structure changes during the heat-set gelation of a number of aqueous (D2O) globular protein solutions. Measurements of the infrared Amide I' absorption band around 1650 cm-1, for BSA gels of varying clarity and texture, have shown that the very considerable variations in network structure underlying these materials are not reflected in obvious differences in secondary structure. In all cases aggregation is accompanied by development of beta-sheet of a kind common in fibrous protein systems, but for BSA at least this does not appear to vary significantly in amount from one gel type to another. Infrared studies of gels formed from other protein systems have confirmed this tendency for beta-sheet to develop during aggregation, and the tendency is further substantiated by laser-Raman evidence which provides the extra information that in most of the examples studied alpha-helix content simultaneously falls. From these, and other observations, some generalisations are made about the thermally-induced sol-to-gel transformations of globular proteins.

  3. Conformational aspects of dibenzo-tetroxecin: A structural, Raman spectroscopic and computational study

    Science.gov (United States)

    Gordon, Keith C.; McAdam, C. John; Moratti, Stephen C.; Shillito, Georgina E.; Simpson, Jim

    2017-10-01

    Crystalline dibenzo-tetroxecin (I) has been prepared from a reaction between catechol and dichloromethane and its molecular and crystal structure, together with the Raman spectrum of the material in the solid state and in solution, is reported. The molecular structure shows the molecule adopts an anti or stepped conformation. Density functional theory (DFT) optimisation and frequency calculations using the B3LYP functional with the 6-31G(d) basis set showed the presence of syn- and anti-conformers of (I), with the anti-conformer predicted to be the lower in energy by 13.6 kJ mol-1. The vibrational frequencies and relative Raman intensities of the anti-conformer are well modelled by the DFT calculations. The bond lengths and angles obtained for the anti-conformer are also in good agreement with the crystal structure. The crystal structure of (I) is stabilised by intermolecular Csbnd H⋯O hydrogen bonds that generate a three dimensional network.

  4. Raman spectroscopic detection of peripheral nerves towards nerve-sparing surgery

    Science.gov (United States)

    Minamikawa, Takeo; Harada, Yoshinori; Takamatsu, Tetsuro

    2017-02-01

    The peripheral nervous system plays an important role in motility, sensory, and autonomic functions of the human body. Preservation of peripheral nerves in surgery, namely nerve-sparing surgery, is now promising technique to avoid functional deficits of the limbs and organs following surgery as an aspect of the improvement of quality of life of patients. Detection of peripheral nerves including myelinated and unmyelinated nerves is required for the nerve-sparing surgery; however, conventional nerve identification scheme is sometimes difficult to identify peripheral nerves due to similarity of shape and color to non-nerve tissues or its limited application to only motor peripheral nerves. To overcome these issues, we proposed a label-free detection technique of peripheral nerves by means of Raman spectroscopy. We found several fingerprints of peripheral myelinated and unmyelinated nerves by employing a modified principal component analysis of typical spectra including myelinated nerve, unmyelinated nerve, and adjacent tissues. We finally realized the sensitivity of 94.2% and the selectivity of 92.0% for peripheral nerves including myelinated and unmyelinated nerves against adjacent tissues. Although further development of an intraoperative Raman spectroscopy system is required for clinical use, our proposed approach will serve as a unique and powerful tool for peripheral nerve detection for nerve-sparing surgery in the future.

  5. [Raman spectroscopic study of binary PbO-TeO2 glasses].

    Science.gov (United States)

    Huang, Li; You, Jing-Lin; Chen, Hui; Jiang, Guo-Chang

    2008-07-01

    Raman spectra of lead tellurite glasses and their melts were measured. Results show that four coordinate tellurite units convert into three coordinate units with increasing the concentration of PbO, and the number of non-bridging oxygen bonds (NBO) increases accordingly in this system. Three spectral peaks in the high frequency range were assigned to stretching vibration of bridging oxygen in four coordinate tellurite units (Q(b)), stretching vibration of non-bridging oxygen in four coordinate tellurite units (Q(nb)) and in three coordinate tellurite units (T(nb)). The relative density of four coordinate structure units decreases and the three coordinate tellurite units considerably exist in tellurite glasses when the concentration of PbO > 50%. Besides, the Raman frequencies of the three species' peaks become blue-shifted because of the temperature induced crystallization at high temperature, and the peak intensities increase and the peaks sharpen. The peaks merge together and become much broader while the glass is heated above the melting point because of multiple microstructure units coexisting.

  6. Polarized Raman spectroscopic study of relaxed high density amorphous ices under pressure.

    Science.gov (United States)

    Suzuki, Yoshiharu; Tominaga, Yasunori

    2010-10-28

    We have made high density amorphous ice (HDA) by the pressure-induced amorphization of hexagonal ice at 77 K and measured the volume change on isobaric heating in a pressure range between 0.1 and 1.5 GPa. The volume of HDA on heating below ∼0.35 GPa increases, while the volume of HDA on heating above ∼0.35 GPa decreases. The polarized OH-stretching Raman spectra of the relaxed HDAs are compared with that of the unannealed HDA. The relaxed HDAs are prepared at 0.2 GPa at 130 K and 1.5 GPa at 160 K. It is found that the relatively strong totally symmetric OH-stretching vibration mode around 3100 cm(-1) exists in the depolarized reduced Raman spectrum χ(VH)(") of the unannealed HDA and that its intensity rapidly decreases by relaxation. The χ(VH)(") profiles of the relaxed HDA are similar to those of liquid water. These results indicate that the HDA reaches a nearly equilibrium state by annealing and the intrinsic state of HDA relates to a liquid state. The pressure-volume curve of the relaxed HDA at 140 K seems to be smooth in the pressure range below 1.5 GPa.

  7. Raman and 11B nuclear magnetic resonance spectroscopic studies of alkaline-earth lanthanoborate glasses

    International Nuclear Information System (INIS)

    Brow, R.K.; Tallant, D.R.; Turner, G.L.

    1996-01-01

    Glasses from the RO·La 2 O 3 ·B 2 O 3 (R = Mg, Ca, and Ba) systems have been examined. Glass formation is centered along the metaborate tie line, from La(BO 2 ) 3 to R(BO 2 ) 2 . Glasses generally have transition temperatures >600 C and expansion coefficients between 60 x 10 -7 /C and 100 x 10 -7 /C. Raman and solid-state nuclear magnetic resonance spectroscopies reveal changes in the metaborate network that depend on both the [R]:[La] ratio and the type of alkaline-earth ion. The fraction of tetrahedral sites is generally reduced in alkaline-earth-rich glasses, with magnesium glasses possessing the lowest concentration of B[4]. Raman spectra indicate that, with increasing [R]:[La] ratio, the preferred metaborate anion changes from a double-chain structure associated with crystalline La(BO 2 ) 3 to the single-chain and ring metaborate anions found in crystalline R(BO 2 ) 2 phases. In addition, disproportionation of the metaborate anions leads to the formation of a variety of other species, including pyroborates with terminal oxygens and more-polymerized species, such as diborates, with tetrahedral borons. Such structural changes are related to the ease of glass formation and some of the glass properties

  8. Spectroscopic investigation of Indium Bromide for lighting purposes

    NARCIS (Netherlands)

    Mulders, H.C.J.; Kroesen, G.M.W.; Haverlag, M.; Haverlag, M.; Kroesen, G.M.W.; Tagushi, T.

    2010-01-01

    Laser Induced Fluorescence was used to study the radiative properties of InBr for lighting purposes. Results include the temperature dependence of the fluorescence decay time, spectroscopic constants and rotational temperature determination from a LIF spectrum.

  9. Improvement of the spectroscopic investigation of pellet ablation clouds

    International Nuclear Information System (INIS)

    Koubiti, M.; Ferri, S.; Godbert-Mouret, L.; Marandet, Y.; Rosato, J.; Stamm, R.; Goto, M.; Morita, S.

    2012-11-01

    The method allowing the characterization of the so-called ablation cloud of a pellet from its spectroscopic emission lines (intensities and shapes) is described. It is illustrated using measurements concerning carbon and aluminum pellets injected in the Large Helical Devices (LHD). The electron densities in pellet ablation clouds are sufficiently high that the energy levels of the main emitting species are at Local Thermodynamic Equilibrium (LTE). This justifies the electron temperature determination from the measured intensities using Boltzmann plots. In the case of carbon pellet, the C II 723 nm line was previously fitted with a convolution of a Lorentzian and a Gaussian profiles to determine the electron density. It is proposed here to use more elaborate theoretical profiles accounting for the Stark-Zeeman contributions in order to obtain more accurate plasma parameters especially for the high-resolution spectra in which both Zeeman and Stark features are visible. We present some preliminary comparisons with such spectra which were measured recently in LHD and discuss the possible improvement of the considered investigation technique once all the contributions to the line profile are effectively included. (author)

  10. Controlled Clustering of Gold Nanoparticles using Solid-support for Surface-enhanced Raman Spectroscopic Probes

    International Nuclear Information System (INIS)

    Chang, Hyejin; Chae, Jinjoo; Jeong, Hong; Kang, Homan; Lee, Yoonsik

    2014-01-01

    We fabricated small clusters of gold nanoparticles by using solid-supported aggregation of gold nanoparticles. The fabricated Au nanoclusters consisting mainly of dimers showed homogeneous characteristics in cluster size and SERS intensity. The SERS enhancement of 4-ABT molecules in an effective area within 2-nm gap appeared to be approximately 10. Detachment process by ultrasonication was successively carried out in order to use the nanoclusters as SERS probes. The possibility of these clusters as SERS probe was proved in terms of signal and cluster size. Single molecule-level sensitivity of surface-enhanced Raman scattering (SERS) was known approximately fifteen years ago. Ever since there have been many different applications benefiting from the ultra-high sensitivity such as single molecule detection, chemical sensing and bio-molecular probes. Especially, SERS has drawn much attention in bio-multiplexing probes owing to its unique optical characteristics claiming extremely narrow bandwidth, high sensitivity of light signals, and non-bleaching feature

  11. Raman Spectroscopic Studies of Methane-Ethane Mixtures as a Function of Pressure

    DEFF Research Database (Denmark)

    Hansen, Susanne Brunsgaard; Berg, Rolf W.; Stenby, Erling Halfdan

    2001-01-01

    Raman spectra of methane and methane-ethane mixtures (100, 85, and 49 mole % CH4) have been obtained as a function of pressure in the pressure range 0.1 to 15.3 MPaA (MPa absolute). For these mixtures methane nu (1) (symmetric C-H stretching) band positions are given as a function of pressure......; for pure methane they are in agreement with previous results. The new data on the methane nu (1) band position of ethane-containing mixtures clearly depend on the kind of molecules surrounding the vibrating methane molecule. The nu (1) band position decreases with increasing pressure; the stronger...... the dependency, the higher the content of ethane. The ethane nu (1) band position in the two mixtures showed the same kind of dependency, A qualitative explanation for this behavior is attempted, relating it to changes in van der Waals-type interactions on pressure....

  12. Single molecule Raman spectroscopic assay to detect transgene from GM plants.

    Science.gov (United States)

    Kadam, Ulhas S; Chavhan, Rahul L; Schulz, Burkhard; Irudayaraj, Joseph

    2017-09-01

    Substantial concerns have been raised for the safety of transgenics on human health and environment. Many organizations, consumer groups, and environmental agencies advocate for stringent regulations to avoid transgene products' contamination in food cycle or in nature. Here we demonstrate a novel approach using surface enhanced Raman spectroscopy (SERS) to detect and quantify transgene from GM plants. We show a highly sensitive and accurate quantification of transgene DNA from multiple transgenic lines of Arabidopsis. The assay allows us to detect and quantify the transgenes as low as 0.10 pg without need for PCR-amplification. This technology is relatively cheap, quick, simple, and suitable for detection at low target concentration. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Rapid bacterial antibiotic susceptibility test based on simple surface-enhanced Raman spectroscopic biomarkers

    Science.gov (United States)

    Liu, Chia-Ying; Han, Yin-Yi; Shih, Po-Han; Lian, Wei-Nan; Wang, Huai-Hsien; Lin, Chi-Hung; Hsueh, Po-Ren; Wang, Juen-Kai; Wang, Yuh-Lin

    2016-03-01

    Rapid bacterial antibiotic susceptibility test (AST) and minimum inhibitory concentration (MIC) measurement are important to help reduce the widespread misuse of antibiotics and alleviate the growing drug-resistance problem. We discovered that, when a susceptible strain of Staphylococcus aureus or Escherichia coli is exposed to an antibiotic, the intensity of specific biomarkers in its surface-enhanced Raman scattering (SERS) spectra drops evidently in two hours. The discovery has been exploited for rapid AST and MIC determination of methicillin-susceptible S. aureus and wild-type E. coli as well as clinical isolates. The results obtained by this SERS-AST method were consistent with that by the standard incubation-based method, indicating its high potential to supplement or replace existing time-consuming methods and help mitigate the challenge of drug resistance in clinical microbiology.

  14. Neutron spectroscopic and Raman studies of interaction between water and proline

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Peng [Department of Space Science and Applied Physics, Shandong University at Weihai, Weihai 264209 (China); State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China); Han Shenghao [Department of Space Science and Applied Physics, Shandong University at Weihai, Weihai 264209 (China); Zhang Ying [State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China); Ford, Robert C. [MIB, University of Manchester, Manchester M60 1QD (United Kingdom); Li Jichen [Department of Physics and Astronomy, University of Manchester, Manchester M60 1QD (United Kingdom)], E-mail: j.c.li@manchester.ac.uk

    2008-04-18

    A series of measurements for the vibrational dynamics of water around proline were made by using inelastic neutron scattering and Raman spectroscopy techniques. Comparing the spectra at different hydrations, we found that proline has very different hydrophilic property compared with other amino acids we have studied [Y. Zhang et al., J. Phys. Chem. B 109 (2005) 17784]. We interpret these differences in terms of the unique structure of proline with an imino group which is fixed rigidly in the pyrrolidine ring. As result, we may observe a non-ionic form of proline solid transformed to an ionic state after hydration. This phenomenon was not seen in other amino acids we have studied so far.

  15. Controlled Clustering of Gold Nanoparticles using Solid-support for Surface-enhanced Raman Spectroscopic Probes

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hyejin; Chae, Jinjoo; Jeong, Hong [Department of Chemistry Education, Seoul (Korea, Republic of); Kang, Homan; Lee, Yoonsik [Interdisciplinary Program in Nano-Science and Technology, Pohang (Korea, Republic of)

    2014-03-15

    We fabricated small clusters of gold nanoparticles by using solid-supported aggregation of gold nanoparticles. The fabricated Au nanoclusters consisting mainly of dimers showed homogeneous characteristics in cluster size and SERS intensity. The SERS enhancement of 4-ABT molecules in an effective area within 2-nm gap appeared to be approximately 10. Detachment process by ultrasonication was successively carried out in order to use the nanoclusters as SERS probes. The possibility of these clusters as SERS probe was proved in terms of signal and cluster size. Single molecule-level sensitivity of surface-enhanced Raman scattering (SERS) was known approximately fifteen years ago. Ever since there have been many different applications benefiting from the ultra-high sensitivity such as single molecule detection, chemical sensing and bio-molecular probes. Especially, SERS has drawn much attention in bio-multiplexing probes owing to its unique optical characteristics claiming extremely narrow bandwidth, high sensitivity of light signals, and non-bleaching feature.

  16. The effect of phototherapies on bone repair of euthyroid and hypothyroid rats: Raman spectroscopic study

    Science.gov (United States)

    Soares, Amanda P.; Rodriguez, Tania T.; Soares, Luiz G. P.; dos Santos, Jean Nunes; Silveira, Landulfo; Pinheiro, Antonio Luiz B.

    2018-04-01

    The repair of bone tissue is complex and can be influenced by several local and systemic factors that can delay the repair. Laser and LED phototherapies have shown positive results in the repair of bone tissue. The aim of this study was to evaluate, through Raman spectroscopy, the influence of laser (λ780 nm) and LED (λ850 nm) phototherapies in the repair of surgical defects in femurs of euthyroid and hypothyroid rats. Thirty Albinus Wistar rats were randomly divided into 6 groups. The animals of the hypothyroid groups were submitted to surgical removal of the thyroid gland. After general anesthesia, a surgical bone defect was created in the femur of each animal and filled with blood clot in all groups. In group I (Euthyroid) the defect was created in euthyroid animals; In Group II (Hypo) the defect was created in hypothyroid animals; In Group III (Euthyroid Laser) the defect was irradiated with Laser; on Group IV (Hypo Laser) the defect was made in a hypothyroid animal and irradiated with Laser; on Group V (Euthyroid LED) the defect was irradiated with LED and on Group VI (Hypo LED) the defect was created in hypothyroid animals and LED irradiated. Irradiation was carried out at every 48-h for 15 days. Specimens were taken and stored in liquid nitrogen. Intensity of peaks of phosphate HA ( 960 cm-1), carbonated HA ( 1,070 cm-1) and collagen ( 1,414 cm-1) were measured by Raman Spectroscopy. The results showed that the health status had significant influence all peaks. Irradiation influenced only the peak of 1454 cm-1. It is concluded that phototherapies influences bone repair in cases of thyroid diseases.

  17. Micro-Raman depth profile investigations of beveled Al+-ion implanted 6H-SiC samples

    International Nuclear Information System (INIS)

    Zuk, J.; Romanek, J.; Skorupa, W.

    2009-01-01

    6H-SiC single crystals were implanted with 450 keV Al + -ions to a fluence of 3.4 x 10 15 cm -2 , and in a separate experiment subjected to multiple Al + implantations with the four energies: 450, 240, 115 and 50 keV and different fluences to obtain rectangular-like depth distributions of Al in SiC. The implantations were performed along [0 0 0 1] channeling and non-channeling ('random') directions. Subsequently, the samples were annealed for 10 min at 1650 deg. C in an argon atmosphere. The depth profiles of the implanted Al atoms were obtained by secondary ion mass spectrometry (SIMS). Following implantation and annealing, the samples were beveled by mechanical polishing. Confocal micro-Raman spectroscopic investigations were performed with a 532 nm wavelength laser beam of a 1 μm focus diameter. The technique was used to determine precisely the depth profiles of TO and LO phonon lines intensity in the beveled samples to a depth of about 2000 nm. Micro-Raman spectroscopy was also found to be useful in monitoring very low levels of disorder remaining in the Al + implanted and annealed 6H-SiC samples. The micro-Raman technique combined with sample beveling also made it possible the determination of optical absorption coefficient profiles in implanted subsurface layers.

  18. 1064nm FT-Raman spectroscopy for investigations of plant cell walls and other biomass materials

    Science.gov (United States)

    Umesh P. Agarwal

    2014-01-01

    Raman spectroscopy with its various special techniques and methods has been applied to study plant biomass for about 30 years. Such investigations have been performed at both macro- and micro-levels. However, with the availability of the Near Infrared (NIR) (1064 nm) Fourier Transform (FT)-Raman instruments where, in most materials, successful fluorescence suppression...

  19. Spectroscopic [FT-IR and FT-Raman] and molecular modeling (MM) study of benzene sulfonamide molecule using quantum chemical calculations

    Science.gov (United States)

    Vinod, K. S.; Periandy, S.; Govindarajan, M.

    2016-07-01

    The spectroscopic and molecular modeling (MM) study includes, FT-IR, FT-Raman and 13C NMR and 1H NMR spectra of the Benzene sulfonamide were recorded for the analysis. The observed experimental and theoretical frequencies (IR and Raman) were assigned according to their distinctive region. The present study of this title molecule have been carried out by hybrid computational calculations of HF and DFT (B3LYP) methods with 6-311+G(d,p) and 6-311++G(d,p) basis sets and the corresponding results are tabulated. The structural modifications of the compound due to the substitutions of NH2 and SO2 were investigated. The minimum energy conformers of the compound were studied using conformational analysis. The alternations of the vibrational pattern of the base structure related to the substitutions were analyzed. The thermodynamic parameters (such as zero-point vibrational energy, thermal energy, specific heat capacity, rotational constants, entropy, and dipole moment) of Benzene sulfonamide have been calculated. The donor acceptor interactions of the compound and the corresponding UV transitions are found out using NBO analysis. The NMR spectra were simulated by using the gauge independent atomic orbital (GIAO) method with B3LYP methods and the 6-311++G(d,p) basis set and their spectra were simulated and the chemical shifts related to TMS were compared. A quantum computational study on the electronic and optical properties absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, were performed by HF and DFT methods. The energy gap of the present compound was calculated related to HOMO and LUMO energies which confirm the occurring of charge transformation between the base and ligand group. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. The thermodynamic properties (heat capacity, entropy, and enthalpy) of the title compound at different temperatures were calculated in gas phase and

  20. In situ photoelectrochemistry and Raman spectroscopic characterization on the surface oxide film of nickel electrode in 30 wt.% KOH solution

    International Nuclear Information System (INIS)

    Nan Junmin; Yang Yong; Lin Zugeng

    2006-01-01

    The oxide films of nickel electrode formed in 30 wt.% KOH solution under potentiodynamic conditions were characterized by means of electrochemical, in situ PhotoElectrochemistry Measurement (PEM) and Confocal Microprobe Raman spectroscopic techniques. The results showed that a composite oxide film was produced on nickel electrode, in which aroused cathodic or anodic photocurrent depending upon polarization potentials. The cathodic photocurrent at -0.8 V was raised from the amorphous film containing nickel hydroxide and nickel monoxide, and mainly attributed to the formation of NiO through the separation of the cavity and electron when laser light irradiates nickel electrode. With the potential increasing to more positive values, Ni 3 O 4 and high-valence nickel oxides with the structure of NiO 2 were formed successively. The composite film formed in positive potential aroused anodic photocurrent from 0.33 V. The anodic photocurrent was attributed the formation of oxygen through the cavity reaction with hydroxyl on solution interface. In addition, it is demonstrated that the reduction resultants of high-valence nickel oxides were amorphous, and the oxide film could not be reduced completely. A stable oxide film could be gradually formed on the surface of nickel electrode with the cycling and aging in 30 wt.% KOH solution

  1. Romano-British wall paintings: Raman spectroscopic analysis of fragments from two urban sites of early military colonisation

    Science.gov (United States)

    Edwards, H. G. M.; Middleton, P. S.; Hargreaves, M. D.

    2009-08-01

    Raman spectroscopic analyses of 1st century AD Romano-British villa wall-painting fragments from two important military and early urban centres at Colchester and Lincoln have demonstrated some interesting contrasts in technique and palette usage. Colchester, the earliest fortified settlement, developed a sophisticated painting and craft industry compared with Lincoln in the assimilation of novel substrate preparation ideas and pigment adoption. The earliest use of the rather rare purple mineral pigment, caput mortuum, hitherto reported in only a few Roman villas elsewhere in mainland Europe, is in evidence in this early phase settlement and the use of gypsum as a special ground preparation agent as an additive to the more common limewash putty to enhance the effect of the use of lazurite as a pigment is worthy of note in this context. Otherwise, the pigments are seen to be those that are quite normally encountered in Roman villas, namely, haematite, goethite, terre verte, and carbon. The results of this study indicate that at Colchester there was a continued development in technique into the colonial phase compared with a stagnation in Lincoln; these scientific results have created a stimulus for further historical research into pigment and techniques development for wall paintings at the fringe of the Roman Empire in the 1st-3rd Centuries AD.

  2. Surface-enhanced Raman spectroscopic monitor of triglyceride hydrolysis in a skin pore phantom

    Science.gov (United States)

    Weldon, Millicent K.; Morris, Michael D.

    1999-04-01

    Bacterial hydrolysis of triglycerides is followed in a sebum probe phantom by microprobe surface-enhanced Raman scattering (SERS) spectroscopy. The phantom consists of a purpose-built syringe pump operating at physiological flow rates connected to a 300 micron i.d. capillary. We employ silicon substrate SERS microprobes to monitor the hydrolysis products. The silicon support allows some tip flexibility that makes these probes ideal for insertion into small structures. Propionibacterium acnes are immobilized on the inner surface of the capillary. These bacteria hydrolyze the triglycerides in a model sebum emulsion flowing through the capillary. The transformation is followed in vitro as changes in the SERS caused by hydrolysis of triglyceride to fatty acid. The breakdown products consists of a mixture of mono- and diglycerides and their parent long chain fatty acids. The fatty acids adsorb as their carboxylates and can be readily identified by their characteristic spectra. The technique can also confirm the presence of bacteria by detection of short chain carboxylic acids released as products of glucose fermentation during the growth cycle of these cells. Co-adsorption of propionate is observed. Spatial localization of the bacteria is obtained by ex-situ line imaging of the probe.

  3. Electrical and Raman spectroscopic studies of vertically aligned multi-walled carbon nanotubes.

    Science.gov (United States)

    Mathur, Ashish; Tweedie, Mark; Roy, Susanta Sinha; Maguire, P D; McLaughlin, James A

    2009-07-01

    Microwave plasma enhanced chemical vapour deposition (MPECVD) was used for the production of carbon nanotubes. Vertically aligned multi-walled carbon nanotubes (MWCNTs) were grown on silicon substrates coated with cobalt thin films of thickness ranging from 0.5 nm to 3 nm. Prior to the nanotube growth the catalyst were treated with N2 plasma for 5-10 minutes that break the films into small nanoparticles which favour the growth of nanotubes. The CNTs were grown at a substrate temperature of 700 degrees C for 5, 10 and 15 minutes. The height of the CNT films ranging from 10 microm-30 microm indicating that the initial growth rate of the CNTs are very high at a rate of approximately 100 nm/sec. Electrical resistivity of the above samples was evaluated from I-V measurements. The activation energy (E(a)) was also calculated from the temperature dependent studies and it was found that the E(a) lies in the range of 15-35 meV. Raman spectroscopy was used to identify the quality of the nanotubes.

  4. Resonance Raman Spectroscopic Evaluation of Skin Carotenoids as a Biomarker of Carotenoid Status for Human Studies

    Science.gov (United States)

    Mayne, Susan T.; Cartmel, Brenda; Scarmo, Stephanie; Jahns, Lisa; Ermakov, Igor V.; Gellermann, Werner

    2013-01-01

    Resonance Raman Spectroscopy (RRS) is a non-invasive method that has been developed to assess carotenoid status in human tissues including human skin in vivo. Skin carotenoid status has been suggested as a promising biomarker for human studies. This manuscript describes research done relevant to the development of this biomarker, including its reproducibility, validity, feasibility for use in field settings, and factors that affect the biomarker such as diet, smoking, and adiposity. Recent studies have evaluated the response of the biomarker to controlled carotenoid interventions, both supplement-based and dietary [e.g., provision of a high-carotenoid fruit and vegetable (F/V)-enriched diet], demonstrating consistent response to intervention. The totality of evidence supports the use of skin carotenoid status as an objective biomarker of F/V intake, although in the cross-sectional setting, diet explains only some of the variation in this biomarker. However, this limitation is also a strength in that skin carotenoids may effectively serve as an integrated biomarker of health, with higher status reflecting greater F/V intake, lack of smoking, and lack of adiposity. Thus, this biomarker holds promise as both a health biomarker and an objective indicator of F/V intake, supporting its further development and utilization for medical and public health purposes. PMID:23823930

  5. Raman spectroscopy as a tool for investigating lipid protein interactions

    DEFF Research Database (Denmark)

    Petersen, Frederic Nicolas Rønne; Helix Nielsen, Claus

    2009-01-01

    ]) as well as improved technical equipment for signal capture (such as improved sensitivity of charge-coupled devices [CCDs]). Combined, these technological advances have brought Raman spectroscopy into a new era in which hitherto inaccessible or hardly accessible research areas now are becoming possible...

  6. Heating stage Raman and infrared emission spectroscopic study of the dehydroxylation of synthetic Mg-hydrotalcite

    International Nuclear Information System (INIS)

    Kloprogge, J.T.; Hickey, L.; Frost, R.L.

    1998-01-01

    Spectroscopy (IES) and heating stage Raman microscopy. Heating stage Raman microscopy reveals that upon heating and subsequent dehydration the bands at 553, 1052, 3503, 3603 and 3689 cm -1 associated with the (Mg, A1) 3 -OH translation, deformation and stretching vibrations decrease in intensity due to changes in the stacking order of the hydroxide layers. During this rearrangement around 150-175deg C the free interlayer nitrate forms a type of bridging nitrato complex with the metals in the hydroxide layers as evidenced by the disappearance of the normal free nitrate vibrations at 716, 1067 and 1386 cm -1 and the formation of a new band at 1039 cm -1 . Further heating to 300 deg C results in the dehydroxylation and decarbonisation of the hydrotalcite, which is only partially reversed upon cooling in air over a period of more than 12 hours. The Mg-hydrotalcite IES spectra show major changes around 350-400 deg C indicating the end of the dehydroxylation. In this temperature range Al-OH bands at 772, 923 and 1029 cm -1 disappear. New bands are observed around 713, 797 and 1075 cm -1 . The first and the last band plus the 545 cm -1 band indicate the formation of spinel (MgAl 2 O 4 ). The band around 713 cm -1 is also close to the ν LO position of MgO at 717 cm -1 , which is another product formed after dehydroxylation. However, decarbonisation is not complete at this stage as evidenced by both a continuing weight loss in the TGA up to at least 625 deg C and a decreasing carbonate signal in the IES up to 800 deg C

  7. Quantum computational studies, spectroscopic (FT-IR, FT-Raman and UV-Vis) profiling, natural hybrid orbital and molecular docking analysis on 2,4 Dibromoaniline

    Science.gov (United States)

    Abraham, Christina Susan; Prasana, Johanan Christian; Muthu, S.; Rizwana B, Fathima; Raja, M.

    2018-05-01

    The research exploration will comprise of investigating the molecular structure, vibrational assignments, bonding and anti-bonding nature, nonlinear optical, electronic and thermodynamic nature of the molecule. The research is conducted at two levels: First level employs the spectroscopic techniques - FT-IR, FT-Raman and UV-Vis characterizing techniques; at second level the data attained experimentally is analyzed through theoretical methods using and Density Function Theories which involves the basic principle of solving the Schrodinger equation for many body systems. A comparison is drawn between the two levels and discussed. The probability of the title molecule being bio-active theoretically proved by the electrophilicity index leads to further property analyzes of the molecule. The target molecule is found to fit well with Centromere associated protein inhibitor using molecular docking techniques. Higher basis set 6-311++G(d,p) is used to attain results more concurrent to the experimental data. The results of the organic amine 2, 4 Dibromoaniline is analyzed and discussed.

  8. Surface enhanced Raman spectroscopic direct determination of low molecular weight biothiols in umbilical cord whole blood.

    Science.gov (United States)

    Kuligowski, Julia; El-Zahry, Marwa R; Sánchez-Illana, Ángel; Quintás, Guillermo; Vento, Máximo; Lendl, Bernhard

    2016-04-07

    Biothiols play an essential role in a number of biological processes in living organisms including detoxification and metabolism. Fetal to neonatal transition poses a pro-oxidant threat for newborn infants, especially those born prematurely. A reliable and rapid tool for the direct determination of thiols in small volume whole blood (WB) samples would be desirable for its application in clinical practice. This study shows the feasibility of Surface Enhanced Raman Spectroscopy (SERS) using a silver colloid prepared by reduction of silver nitrate using hydroxylamine, as the SERS substrate for the quantification of thiols in WB samples after a simple precipitation step for protein removal. Bands originating from biothiols (790, 714 and 642 cm(-1)) were enhanced by the employed SERS substrate and the specificity of the detected SERS signal was tested for molecules presenting -SH functional groups. A statistically significant correlation between the obtained SERS signals and the thiol concentration measured using a chromatographic reference method in umbilical cord WB samples could be demonstrated. Using WB GSH concentrations obtained from the chromatographic reference procedure, a Partial Least Squares (PLS) regression model covering GSH concentrations from 13 to 2200 μM was calculated obtaining a root mean square error of prediction (RMSEP) of 381 μM when applied to an external test set. The developed approach uses small blood sample volumes (50 μL), which is important for clinical applications, especially in the field of neonatology. This feasibility study shows that the present approach combines all the necessary characteristics for its potential application in clinical practice.

  9. Sequence dependent DNA conformations: Raman spectroscopic studies and a model of action of restriction enzymes

    International Nuclear Information System (INIS)

    Nishimura, Y.

    1985-01-01

    Raman spectra have been examined to clarify the polymorphic forms of DNA, A, B, and Z forms. From an analysis the authors found that the guanine ring breathing vibration is sensitive to its local conformation. Examination of nine crystals of guanosine residues in which the local conformations are well established revealed that a guanosine residue with a C3'endo-anti gives a strong line at 666+-2 cm/sup -1/, O4'endo-anti at 682 cm/sup -1/, C1'exo-anti at 673 cm/sup -1/, C2'endo-anti at 677 cm/sup -1/ and syn-forms around 625 cm/sup -1/. Using this characteristic line, they were able to obtain the local conformations of guanosine moieties in poly(dG-dC). Such a sequence derived variation is suggested to be recognized by sequence specific proteins such as restriction enzymes. The authors found a correlation between sequence dependent DNA conformation and a mode of action of restriction enzymes. The cutting mode of restriction enzymes is classified into three groups. The classification of whether the products have blunt ends, two-base-long cohesive ends, or four-base-long cohesive ends depends primarily on the substrate, not on the enzyme. It is suggested that sequence dependent DNA conformation causes such a classification by the use of the Calladine-Dickerson analysis. In the recognition of restriction enzymes, the methyl group in a certain sequence is considered to play an important role by changing the local conformation of DNA

  10. An Ultraviolet Resonance Raman Spectroscopic Study of Cisplatin and Transplatin Interactions with Genomic DNA.

    Science.gov (United States)

    Geng, Jiafeng; Aioub, Mena; El-Sayed, Mostafa A; Barry, Bridgette A

    2017-09-28

    Ultraviolet resonance Raman (UVRR) spectroscopy is a label-free method to define biomacromolecular interactions with anticancer compounds. Using UVRR, we describe the binding interactions of two Pt(II) compounds, cisplatin (cis-diamminedichloroplatinum(II)) and its isomer, transplatin, with nucleotides and genomic DNA. Cisplatin binds to DNA and other cellular components and triggers apoptosis, whereas transplatin is clinically ineffective. Here, a 244 nm UVRR study shows that purine UVRR bands are altered in frequency and intensity when mononucleotides are treated with cisplatin. This result is consistent with previous suggestions that purine N7 provides the cisplatin-binding site. The addition of cisplatin to DNA also causes changes in the UVRR spectrum, consistent with binding of platinum to purine N7 and disruption of hydrogen-bonding interactions between base pairs. Equally important is that transplatin treatment of DNA generates similar UVRR spectral changes, when compared to cisplatin-treated samples. Kinetic analysis, performed by monitoring decreases of the 1492 cm -1 band, reveals biphasic kinetics and is consistent with a two-step binding mechanism for both platinum compounds. For cisplatin-DNA, the rate constants (6.8 × 10 -5 and 6.5 × 10 -6 s -1 ) are assigned to the formation of monofunctional adducts and to bifunctional, intrastrand cross-linking, respectively. In transplatin-DNA, there is a 3.4-fold decrease in the rate constant of the slow phase, compared with the cisplatin samples. This change is attributed to generation of interstrand, rather than intrastrand, adducts. This longer reaction time may result in increased competition in the cellular environment and account, at least in part, for the lower pharmacological efficacy of transplatin.

  11. In-line Raman spectroscopic monitoring and feedback control of a continuous twin-screw pharmaceutical powder blending and tableting process.

    Science.gov (United States)

    Nagy, Brigitta; Farkas, Attila; Gyürkés, Martin; Komaromy-Hiller, Szofia; Démuth, Balázs; Szabó, Bence; Nusser, Dávid; Borbás, Enikő; Marosi, György; Nagy, Zsombor Kristóf

    2017-09-15

    The integration of Process Analytical Technology (PAT) initiative into the continuous production of pharmaceuticals is indispensable for reliable production. The present paper reports the implementation of in-line Raman spectroscopy in a continuous blending and tableting process of a three-component model pharmaceutical system, containing caffeine as model active pharmaceutical ingredient (API), glucose as model excipient and magnesium stearate as lubricant. The real-time analysis of API content, blend homogeneity, and tablet content uniformity was performed using a Partial Least Squares (PLS) quantitative method. The in-line Raman spectroscopic monitoring showed that the continuous blender was capable of producing blends with high homogeneity, and technological malfunctions can be detected by the proposed PAT method. The Raman spectroscopy-based feedback control of the API feeder was also established, creating a 'Process Analytically Controlled Technology' (PACT), which guarantees the required API content in the produced blend. This is, to the best of the authors' knowledge, the first ever application of Raman-spectroscopy in continuous blending and the first Raman-based feedback control in the formulation technology of solid pharmaceuticals. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Ultrafast spectroscopic investigation of a fullerene poly(3-hexylthiophene) dyad

    Science.gov (United States)

    Banerji, Natalie; Seifter, Jason; Wang, Mingfeng; Vauthey, Eric; Wudl, Fred; Heeger, Alan J.

    2011-08-01

    We present the femtosecond spectroscopic investigation of a covalently linked dyad, PCB-P3HT, formed by a segment of the conjugated polymer P3HT (regioregular poly(3-hexylthiophene)) that is end capped with the fullerene derivative PCB ([6,6]-phenyl-C61-butyric acid ester), adapted from PCBM. The fluorescence of the P3HT segment in tetrahydrofuran (THF) solution is reduced by 64% in the dyad compared to a control compound without attached fullerene (P3HT-OH). Fluorescence upconversion measurements reveal that the partial fluorescence quenching of PCB-P3HT in THF is multiphasic and occurs on an average time scale of 100 ps, in parallel to excited-state relaxation processes. Judging from ultrafast transient absorption experiments, the origin of the quenching is excitation energy transfer from the P3HT donor to the PCB acceptor. Due to the much higher solubility of P3HT compared to PCB in THF, the PCB-P3HT dyad molecules self-assemble into micelles. When pure C60 is added to the solution, it is incorporated into the fullerene-rich center of the micelles. This dramatically increases the solubility of C60 but does not lead to significant additional quenching of the P3HT fluorescence by the C60 contained in the micelles. In PCB-P3HT thin films drop-cast from THF, the micelle structure is conserved. In contrast to solution, quantitative and ultrafast (microscopy images. Ultrafast charge separation occurs also for the fibrous morphology, but the transient absorption experiments show fast loss of part of the charge carriers due to intensity-induced recombination and annihilation processes and monomolecular interfacial trap-mediated or geminate recombination. The yield of the long-lived charge carriers in the highly organized fibers is however comparable to that obtained with annealed P3HT:PCBM blends. PCB-P3HT can therefore be considered as an active material in organic photovoltaic devices.

  13. Raman and X-ray absorption spectroscopic studies of hydrothermally altered alkali-borosilicate nuclear waste glass

    Energy Technology Data Exchange (ETDEWEB)

    McKeown, David A., E-mail: davidm@vsl.cua.ed [Vitreous State Laboratory, Catholic University of America, 620 Michigan Ave., N.E., Washington, DC 20064 (United States); Buechele, Andrew C.; Viragh, Carol; Pegg, Ian L. [Vitreous State Laboratory, Catholic University of America, 620 Michigan Ave., N.E., Washington, DC 20064 (United States)

    2010-04-01

    Raman spectroscopy and X-ray absorption spectroscopy (XAS) are used to characterize structural changes that took place in hydrothermally altered (Na,K)-alumina-borosilicate glasses with different Na/K ratios, formulated as part of a durability study to investigate the behavior of glasses for nuclear waste storage. The hydrothermal experiments, or vapor hydration tests (VHT), were performed on each glass for 3 and 20 days at 200 deg. C to accelerate and approximate long-term alteration processes that may occur in a nuclear waste repository. Results found for both glasses and their VHT altered counterparts show little, if any, structural influence from the different starting Na/K ratios. X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, and Raman spectroscopy indicate that the altered samples are mostly amorphous with small amounts of analcime-like and leucite-like crystals within 200 mum of the sample surface and contain up to 9.7 wt.% water or OH. The Raman data are nearly identical for the amorphous portions of all altered VHT samples investigated, and indicate that two glass structural changes took place during alteration: one, partial depolymerization of the alumina-borosilicate network, and two, introduction of water or OH. Al and Si XAS data indicate tetrahedral AlO{sub 4} and SiO{sub 4} environments in the original glasses as well as in the altered samples. Small energy shifts of the Si K-edge also show that the altered VHT samples have less polymerized networks than the original glass. Na XAS data indicate expanded Na environments in the VHT samples with longer Na-O distances and more nearest-neighbor oxygen atoms, compared with the original glasses, which may be due to hydrous species introduced into the expanding Na-sites.

  14. Raman Mapping for the Investigation of Nano-phased Materials

    Science.gov (United States)

    Gouadec, G.; Bellot-Gurlet, L.; Baron, D.; Colomban, Ph.

    Nanosized and nanophased materials exhibit special properties. First they offer a good compromise between the high density of chemical bonds by unit volume, needed for good mechanical properties and the homogeneity of amorphous materials that prevents crack initiation. Second, interfaces are in very high concentration and they have a strong influence on many electrical and redox properties. The analysis of nanophased, low crystallinity materials is not straigtforward. The recording of Raman spectra with a geometric resolution close to 0.5 \\upmu {text{ m}^3} and the deep understanding of the Raman signature allow to locate the different nanophases and to predict the properties of the material. Case studies are discussed: advanced polymer fibres, ceramic fibres and composites, textured piezoelectric ceramics and corroded (ancient) steel.

  15. Electrochemical and spectroscopic in situ techniques for the investigation of the phosphating of zinc coated steel

    International Nuclear Information System (INIS)

    Tomandl, A.

    2003-05-01

    In this work spectroscopic and electrochemical techniques were developed for the investigation of surface treatments used in steel industry. ICP-atomic emission spectroscopy (ICP-AES), Raman spectroscopy and the Quartz crystal microbalance (QCM) were applied to the investigation of the kinetics of phosphating as well as the properties of phosphate layers. Phosphating of zinc coated steel leads to the formation of a crystalline layer consisting of zinc phosphate and is employed to enhance paint adhesion and corrosion protection. For the high reaction rates necessary in industrial production lines, oxidation agents are added to the phosphating bathes to accelerate the reaction. The oxidation agents provide an additional reduction reaction beside the hydrogen formation and therefore decrease the number of gas bubbles, which would block the zinc surface and reduce the rate of phosphating. With addition of H2O2 or nitrates the rate of layer formation is distinctly increased. In a combined experiment of ICP-AES with QCM and potential transients, it was shown that the presence of these accelerators in the phosphating bath increases the rate of zinc dissolution and hence leads to a faster formation of the phosphate layer. In under paint corrosion of painted, zinc coated steel phosphate layers are exposed to a highly alkaline environment. The stability of a phosphate layer against alkaline attack is therefore essential for its performance in corrosion protection. To enhance the alkaline stability Mn and Ni are added to modern phosphating bathes. The incorporation of these elements reduces the dissolution rate in 0.1 M NaOH proportional to their concentration in the phosphate layer. The dissolution of Zn, P, Mn and Ni was determined quantitatively with ICP-AES. Raman spectroscopy showed the formation of a Mn-hydroxide layer during alkaline attack, which protects the phosphate layer and reduces further dissolution. On basis of these results the reaction of phosphate layers

  16. Raman spectroscopic analysis of cyanogenic glucosides in plants: development of a Flow Injection Surface-Enhanced Raman Scatter (FI-SERS) method for determination of cyanide

    DEFF Research Database (Denmark)

    Thygesen, Lisbeth Garbrecht; Jørgensen, Kirsten; Møller, Birger Lindberg

    2004-01-01

    Cyanogenic glucosides were studied using Raman spectroscopy. Spectra of the crystal forms of linamarin, linustatin, neolinustatin, amygdalin, sambunigrin, and dhurrin were obtained using a Raman spectrograph microscope equipped with a 532 nm laser. The position of the signal from the CdropN tripl...

  17. Raman and infrared spectroscopic studies of the structure of water (H2O, HOD, D2O) in stoichiometric crystalline hydrates and in electrolyte solutions

    International Nuclear Information System (INIS)

    Buanam-Om, C.

    1981-01-01

    The chapter of reviews presents in particular the Badger-Bauer-rule, distance and angle dependence of O-H...Y hydrogen bond and the structure of aqueous electrolyte solutions. A chapter of vibrational spectroscopic investigations of crystalline hydrates - metal perchlorate hydrates follows. Two further chapters just so investigate metal halide hydrates and some sulfate hydrates and related systems. The following chapter describes near infrared spectroscopic investigations of HOD(D 2 O) and its electrolyte solutions. The concluding chapter contains thermodynamic consequences and some properties of electrolyte solutions from vibrational spectroscopic investigations. (SPI) [de

  18. Spectroscopic (UV/VIS, Raman) and Electrophoresis Study of Cytosine-Guanine Oligonucleotide DNA Influenced by Magnetic Field.

    Science.gov (United States)

    Banihashemian, Seyedeh Maryam; Periasamy, Vengadesh; Boon Tong, Goh; Abdul Rahman, Saadah

    2016-01-01

    Studying the effect of a magnetic field on oligonucleotide DNA can provide a novel DNA manipulation technique for potential application in bioengineering and medicine. In this work, the optical and electrochemical response of a 100 bases oligonucleotides DNA, cytosine-guanine (CG100), is investigated via exposure to different magnetic fields (250, 500, 750, and 1000 mT). As a result of the optical response of CG100 to the magnetic field, the ultra-violet-visible spectrum indicated a slight variation in the band gap of CG100 of about 0.3 eV. Raman spectroscopy showed a significant deviation in hydrogen and phosphate bonds' vibration after exposure to the magnetic field. Oligonucleotide DNA mobility was investigated in the external electric field using the gel electrophoresis technique, which revealed a small decrease in the migration of CG100 after exposure to the magnetic field.

  19. Spectroscopic (UV/VIS, Raman and Electrophoresis Study of Cytosine-Guanine Oligonucleotide DNA Influenced by Magnetic Field.

    Directory of Open Access Journals (Sweden)

    Seyedeh Maryam Banihashemian

    Full Text Available Studying the effect of a magnetic field on oligonucleotide DNA can provide a novel DNA manipulation technique for potential application in bioengineering and medicine. In this work, the optical and electrochemical response of a 100 bases oligonucleotides DNA, cytosine-guanine (CG100, is investigated via exposure to different magnetic fields (250, 500, 750, and 1000 mT. As a result of the optical response of CG100 to the magnetic field, the ultra-violet-visible spectrum indicated a slight variation in the band gap of CG100 of about 0.3 eV. Raman spectroscopy showed a significant deviation in hydrogen and phosphate bonds' vibration after exposure to the magnetic field. Oligonucleotide DNA mobility was investigated in the external electric field using the gel electrophoresis technique, which revealed a small decrease in the migration of CG100 after exposure to the magnetic field.

  20. Investigation by raman spectroscopy of the decomposition process of HKUST-1 upon exposure to air

    OpenAIRE

    Todaro, M.; Alessi, A.; Sciortino, L.; Agnello, S.; Cannas, M.; Gelardi, F.; Buscarino, G.

    2016-01-01

    We report an experimental investigation by Raman spectroscopy of the decomposition process of Metal-Organic Framework (MOF) HKUST-1 upon exposure to air moisture (T=300 K, 70% relative humidity). The data collected here are compared with the indications obtained from a model of the process of decomposition of this material proposed in literature. In agreement with that model, the reported Raman measurements indicate that for exposure times longer than 20 days relevant irreversible processes t...

  1. In-situ Raman and X-ray photoelectron spectroscopic studies on the pitting corrosion of modified 9Cr-1Mo steel in neutral chloride solution

    Science.gov (United States)

    Ramya, S.; Nanda Gopala Krishna, D.; Mudali, U. Kamachi

    2018-01-01

    In-situ Raman and X-ray photoelectron spectroscopic studies were performed for the identification of native and corroded surface oxide layers of modified 9Cr-1Mo steel. The Raman data obtained for native oxide layer of modified 9Cr-1Mo steel revealed that it was mainly composed of oxides of Fe and Cr. The presence of alloying element Mo was found to be less significant in the native oxide film. The oxides of Cr were dominant at the surface and were found to be decreasing closer to metal/oxide layer interface. The changes in the chemical composition of the native films upon in-situ pitting during potentiostatic polarization experiment were characterized by in-situ Raman analysis. The corrosion products of potentiostatically polarized modified 9Cr-1Mo steel was composed of dominant Fe (III) phases viz., γ- Fe2O3, α and γ - FeOOH along with the oxides of chromium. The results from Raman analysis were corroborated with the XPS experiments on as received and pitted samples of modified 9Cr-1Mo steel specimens. It was observed that the oxides of Cr and Mo contributed for the stability of the surface layer by forming Cr2O3 and MoO3. Also, the study attempted to find out the intermediate corrosion products inside the metastable pits to account for the pseudo passive behavior of modified 9Cr-1Mo steel in 0.1 M NaCl solution.

  2. Raman-spectroscopic (Fe/Fe+Mg, CO2) and Structural studies of Mg-Fe cordierites

    International Nuclear Information System (INIS)

    Haefeker, U.

    2013-01-01

    In the course of this dissertation synthetic hexagonal and orthorhombic Mg-Fe-cordierites have been investigated with Raman-spectroscopy and XRD methods. Cordierite´s Mg- and Fe-end-members as well as their Mg-Fe solid solutions with the chemical formula (Mg, Fe 2+ ) 2 Al 4 Si 5 O 18 *nH 2 O have been synthesized. Raman-data of synthetic hydrous Mg- and Fe-cordierites have been obtained in the wavenumber-region 100-1250 cm-1 and the experimental data were then compared with the results of quantum-mechanical calculations. 86 theoretical bands could be related to specific vibrational modes of the tetrahedral and octahedral sites of the cordierite structure. Maximum and mean deviation between experimentally-derived bands and calculated modes were ±7 cm -1 for Mg-cordierite and ±19 cm -1 for Fe-cordierite. Spectra comparison revealed a trend of peak downshifting as a consequence of Fe-incorporation. The calculations now allow more accurate interpretation of the Raman spectra with respect to structural changes of cordierite, resulting from Al-Si ordering and Mg-Fe exchange. Atomic motions in cordierite have been compared with those of the structurally similar mineral beryl. Investigations of 16 H 2 O-bearing synthetic well-ordered Mg-Fe-cordierites (XFe =0-1) with micro-Raman spectroscopy revealed a linear correlation between the Fe/Mg ratio and the position of certain Raman peaks. The peaks (wave-number Mg-/Fe-cordierite) at 122/111, 262/257, 430/418, 579/571, 974/967, and 1012/1007 cm -1 were selected for a detailed deconvolution analysis . The shifts of these peaks were then plotted vs. XFe and regression of the data lead to the formulation of a set of linear equations. In addition, the effect of different H 2 O contents and the degree of Al-Si ordering on the Fe/Mg determination were also investigated. Testing the calibration against data from six well-characterized natural cordierite samples yielded excellent agreement. Existing calibration diagrams for CO 2

  3. Spectroscopic analysis and molecular docking of imidazole derivatives and investigation of its reactive properties by DFT and molecular dynamics simulations

    Science.gov (United States)

    Thomas, Renjith; Hossain, Mossaraf; Mary, Y. Sheena; Resmi, K. S.; Armaković, Stevan; Armaković, Sanja J.; Nanda, Ashis Kumar; Ranjan, Vivek Kumar; Vijayakumar, G.; Van Alsenoy, C.

    2018-04-01

    Solvent-free synthesis pathway for obtaining two imidazole derivatives (2-chloro-1-(4-methoxyphenyl)-4,5-dimethyl-1H-imidazole (CLMPDI) and 1-(4-bromophenyl)-2-chloro-4,5-dimethyl-1H-imidazole (BPCLDI) has been reported in this work, followed by detailed experimental and computational spectroscopic characterization and reactivity study. Spectroscopic methods encompassed IR, FT-Raman and NMR techniques, with the mutual comparison of experimentally and computationally obtained results at DFT/B3LYP level of theory. Reactivity study based on DFT calculations encompassed molecular orbitals analysis, followed by calculations of molecular electrostatic potential (MEP) and average local ionization energy (ALIE) values, Fukui functions and bond dissociation energies (BDE). Additionally, the stability of title molecules in water has been investigated via molecular dynamics (MD) simulations, while interactivity with aspulvinonedimethylallyl transferase protein has been evaluated by molecular docking procedure. CLMPDI compound showed antimicrobial activity against all four bacterial strain in both gram positive and gram negative bacteria while, BPCLDI showed only in gram positive bacteria, Staphylococcus Aureus (MTCC1144). The first order hyperpolarizability of CLMPDI and BPCLDI are 20.15 and 6.10 times that of the standard NLO material urea.

  4. Investigation of skin cancer treatment efficiency by raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M. S.; Kim, D. W. [Kyungpook National University, Taegu (Korea)

    2000-04-01

    From the successful perform of the molecular structures of various kinds of human skin cancer. We can predict the types of cancer when a small abnormal change change occurs on skin by raman spectrum. When we applied the cancer causing chemicals, bezopyrene, to nude mouse, it did not develop to cancer. But we had radiated UV light after developed to skin cancer in a few days. We can deduce the development of human skin cancer from the result of nude mouse skin cancer, because the two skin are structurally very similar to each other. From the results of own research we could conform the UV light is essential for the development of skin cancer. The results of own research can be directly apply to early detection and proper treatment of skin cancer in hospital. 32 refs., 40 figs., 16 tabs. (Author)

  5. Confinement in single walled carbon nanotubes investigated by spectroscopic ellipsometry

    International Nuclear Information System (INIS)

    Battie, Y.; Jamon, D.; Lauret, J.S.; Gu, Q.; Gicquel-Guézo, M.; En Naciri, A.; Loiseau, A.

    2014-01-01

    Thick films of single walled carbon nanotubes (SWCNTs) with different diameter and chirality distributions are characterized by combining transmission electron microscopy and spectroscopic ellipsometry. The dependence of the dielectric function with the increase of the SWCNT diameter occurs with a drastic redshift of the S 11 , S 22 and M 11 transition energies. The transfer integral parameter γ 0 of SWCNT is also evaluated and analyzed. We demonstrate that parts of the optical properties of SWCNTs are attributed to a one dimensional confinement effect. - Highlights: • Ellipsometric measurements are performed on carbon nanotube thick films. • The complex dielectric functions of conventional carbon nanotubes are given. • Confinement effects explain the variations of dielectric function of nanotubes

  6. Investigation of the S1/ICT equilibrium in fucoxanthin by ultrafast pump-dump-probe and femtosecond stimulated Raman scattering spectroscopy.

    Science.gov (United States)

    Redeckas, Kipras; Voiciuk, Vladislava; Vengris, Mikas

    2016-05-01

    Time-resolved multi-pulse spectroscopic methods-pump-dump-probe (PDP) and femtosecond stimulated Raman spectroscopy-were used to investigate the excited state photodynamics of the carbonyl group containing carotenoid fucoxanthin (FX). PDP experiments show that S1 and ICT states in FX are strongly coupled and that the interstate equilibrium is rapidly (<5 ps) reestablished after one of the interacting states is deliberately depopulated. Femtosecond stimulated Raman scattering experiments indicate that S1 and ICT are vibrationally distinct species. Identification of the FSRS modes on the S1 and ICT potential energy surfaces allows us to predict a possible coupling channel for the state interaction.

  7. Investigation of germanium implanted with aluminum by multi-laser micro-Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sanson, A., E-mail: andrea.sanson@unipd.it [Dipartimento di Fisica e Astronomia, Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); Napolitani, E. [MATIS IMM-CNR at Dipartimento di Fisica e Astronomia, Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); Impellizzeri, G. [MATIS IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, I-95123 Catania (Italy); Giarola, M. [Dipartimento di Informatica, Università di Verona, Strada le Grazie 15, I-37134 Verona (Italy); De Salvador, D. [Dipartimento di Fisica e Astronomia, Università di Padova, Via Marzolo 8, I-35131 Padova (Italy); Privitera, V.; Priolo, F. [MATIS IMM-CNR and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, I-95123 Catania (Italy); Mariotto, G. [Dipartimento di Informatica, Università di Verona, Strada le Grazie 15, I-37134 Verona (Italy); Carnera, A. [Dipartimento di Fisica e Astronomia, Università di Padova, Via Marzolo 8, I-35131 Padova (Italy)

    2013-08-31

    Germanium samples, implanted with aluminum and annealed, have been investigated by micro-Raman spectroscopy using different excitation lines with the aim of gaining insights about the Al distribution at different depths beneath the sample surface and to correlate the Raman spectra with the electrical and chemical profiles, obtained by Spreading Resistance Profiling (SRP) and Secondary Ions Mass Spectrometry (SIMS) measurements, respectively. The intensity of the Al–Ge Raman peak at about 370 cm{sup −1}, due to the local vibrational mode of the substitutional Al atoms in the Ge matrix, has been directly related to the SRP behavior, while no correlation has been observed with SIMS profiles. These findings show that the electrically active content is entirely due to the substitutional Al atoms. Finally, a clear down shift is observed for the Ge–Ge Raman peak at ∼ 300 cm{sup −1}, which also seems to be directly related to the active content of Al dopant atoms. This work shows that micro-Raman spectroscopy can be a suitable tool for the study of doping profiles in Ge. - Highlights: ► Al-implanted Ge and annealed were studied by micro-Raman spectroscopy. ► Using different laser lines we have investigated the implants at different depths. ► The Al–Ge Raman peak at about 370 cm{sup −1} is directly related to the SRP behavior. ► The electrically active content is entirely due to the substitutional Al atoms. ► Carrier effects are observed on the Ge–Ge peak at ∼ 300 cm{sup −1}.

  8. Investigation of germanium implanted with aluminum by multi-laser micro-Raman spectroscopy

    International Nuclear Information System (INIS)

    Sanson, A.; Napolitani, E.; Impellizzeri, G.; Giarola, M.; De Salvador, D.; Privitera, V.; Priolo, F.; Mariotto, G.; Carnera, A.

    2013-01-01

    Germanium samples, implanted with aluminum and annealed, have been investigated by micro-Raman spectroscopy using different excitation lines with the aim of gaining insights about the Al distribution at different depths beneath the sample surface and to correlate the Raman spectra with the electrical and chemical profiles, obtained by Spreading Resistance Profiling (SRP) and Secondary Ions Mass Spectrometry (SIMS) measurements, respectively. The intensity of the Al–Ge Raman peak at about 370 cm −1 , due to the local vibrational mode of the substitutional Al atoms in the Ge matrix, has been directly related to the SRP behavior, while no correlation has been observed with SIMS profiles. These findings show that the electrically active content is entirely due to the substitutional Al atoms. Finally, a clear down shift is observed for the Ge–Ge Raman peak at ∼ 300 cm −1 , which also seems to be directly related to the active content of Al dopant atoms. This work shows that micro-Raman spectroscopy can be a suitable tool for the study of doping profiles in Ge. - Highlights: ► Al-implanted Ge and annealed were studied by micro-Raman spectroscopy. ► Using different laser lines we have investigated the implants at different depths. ► The Al–Ge Raman peak at about 370 cm −1 is directly related to the SRP behavior. ► The electrically active content is entirely due to the substitutional Al atoms. ► Carrier effects are observed on the Ge–Ge peak at ∼ 300 cm −1

  9. Investigation of the Brill transition in nylon 6,6 by Raman, THz-Raman, and two-dimensional correlation spectroscopy.

    Science.gov (United States)

    Bertoldo Menezes, D; Reyer, A; Musso, M

    2018-02-05

    The Brill transition is a phase transition process in polyamides related with structural changes between the hydrogen bonds of the lateral functional groups (CO) and (NH). In this study, we have used the potential of Raman spectroscopy for exploring this phase transition in polyamide 6,6 (nylon 6,6), due to the sensitivity of this spectroscopic technique to small intermolecular changes affecting vibrational properties of relevant functional groups. During a step by step heating and cooling process of the sample we collected Raman spectra allowing us from two-dimensional Raman correlation spectroscopy to identify which spectral regions suffered the largest influence during the Brill transition, and from Terahertz Stokes and anti-Stokes Raman spectroscopy to obtain complementary information, e.g. on the temperature of the sample. This allowed us to grasp signatures of the Brill transition from peak parameters of vibrational modes associated with (CC) skeletal stretches and (CNH) bending, and to verify the Brill transition temperature at around 160°C, as well as the reversibility of this phase transition. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. A surface enhanced Raman scattering spectroscopic study of UO{sub 2}{sup 2+} at trace concentration

    Energy Technology Data Exchange (ETDEWEB)

    Franzen, Carola [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes; Carstensen, Lale [Technische Univ. Dresden (Germany); Firkala, T. [Helmholtz Institute Freiberg for Resource Technology, Freiberg (Germany); Steudtner, Robin [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Resource Ecology

    2017-06-01

    Techniques for rapid screening of uranium in environmental samples are needed. This study entails the development of Surface-Enhanced Raman scattering (SERS) spectroscopy for analyzing uranium(VI) in aqueous media with improved sensitivity.

  11. Automatic and objective oral cancer diagnosis by Raman spectroscopic detection of keratin with multivariate curve resolution analysis

    Science.gov (United States)

    Chen, Po-Hsiung; Shimada, Rintaro; Yabumoto, Sohshi; Okajima, Hajime; Ando, Masahiro; Chang, Chiou-Tzu; Lee, Li-Tzu; Wong, Yong-Kie; Chiou, Arthur; Hamaguchi, Hiro-O.

    2016-01-01

    We have developed an automatic and objective method for detecting human oral squamous cell carcinoma (OSCC) tissues with Raman microspectroscopy. We measure 196 independent Raman spectra from 196 different points of one oral tissue sample and globally analyze these spectra using a Multivariate Curve Resolution (MCR) analysis. Discrimination of OSCC tissues is automatically and objectively made by spectral matching comparison of the MCR decomposed Raman spectra and the standard Raman spectrum of keratin, a well-established molecular marker of OSCC. We use a total of 24 tissue samples, 10 OSCC and 10 normal tissues from the same 10 patients, 3 OSCC and 1 normal tissues from different patients. Following the newly developed protocol presented here, we have been able to detect OSCC tissues with 77 to 92% sensitivity (depending on how to define positivity) and 100% specificity. The present approach lends itself to a reliable clinical diagnosis of OSCC substantiated by the “molecular fingerprint” of keratin.

  12. Raman spectroscopic studies of the interaction of oxalic acid and sodium oxalate used as corrosion inhibitors with copper

    Science.gov (United States)

    Jeziorowski, H.; Moser, B.

    1985-09-01

    The Raman spectra of the liquid-solid interface recorded in situ show the formation of a salt complex of the inhibitor molecules and the copper ions. This suggests that this chemisorbed surface species produces the protective layer.

  13. Proceedings of 4 conference on hyperfine interaction spectroscopic investigations

    International Nuclear Information System (INIS)

    Shpinel', V.S.

    1992-01-01

    Results of theoretical and experimental investigations on nuclear-spectroscopy of hyperfine interactions are presented. Possibility of the data use for technological and materials sceince problems is demonstrated

  14. Micro-Raman investigations of InN-GaN core-shell nanowires on Si (111) substrate

    OpenAIRE

    P. Sangeetha; K. Jeganathan; V. Ramakrishnan

    2013-01-01

    The electron-phonon interactions in InN-GaN core-shell nanowires grown by plasma assisted- molecular beam epitaxy (MBE) on Si (111) substrate have been analysed using micro-Raman spectroscopic technique with the excitation wavelength of 633, 488 and 325 nm. The Raman scattering at 633 nm reveals the characteristic E2 (high) and A1 (LO) phonon mode of InN core at 490 and 590 cm−1 respectively and E2 (high) phonon mode of GaN shell at 573 cm−1. The free carrier concentration of InN core is foun...

  15. A Raman spectroscopic determination of the kinetics of decomposition of ammonium chromate (NH 4) 2CrO 4

    Science.gov (United States)

    De Waal, D.; Heyns, A. M.; Range, K.-J.

    1989-06-01

    Raman spectroscopy was used as a method in the kinetic investigation of the thermal decomposition of solid (NH 4) 2CrO 4. Time-dependent measurements of the intensity of the totally symmetric stretching CrO mode of (NH 4) 2CrO 4 have been made between 343 and 363 K. A short initial acceleratory period is observed at lower temperatures and the decomposition reaction decelerates after the maximum decomposition rate has been reached at all temperatures. These results can be interpreted in terms of the Avrami-Erofe'ev law 1 - (χ r) {1}/{2} = kt , where χr is the fraction of reactant at time t. At 358 K, k is equal to 1.76 ± 0.01 × 10 -3 sec -1 for microcrystals and for powdered samples. Activation energies of 97 ± 10 and 49 ± 0.9 kJ mole -1 have been calculated for microcrystalline and powdered samples, respectively.

  16. Spectroscopic (FT-IR, FT-Raman, 1H- and 13C-NMR, Theoretical and Microbiological Study of trans o-Coumaric Acid and Alkali Metal o-Coumarates

    Directory of Open Access Journals (Sweden)

    Małgorzata Kowczyk-Sadowy

    2015-02-01

    Full Text Available This work is a continuation of research on a correlation between the molecular structure and electronic charge distribution of phenolic compounds and their biological activity. The influence of lithium, sodium, potassium, rubidium and cesium cations on the electronic system of trans o-coumaric (2-hydroxy-cinnamic acid was studied. We investigated the relationship between the molecular structure of the tested compounds and their antimicrobial activity. Complementary molecular spectroscopic techniques such as infrared (FT-IR, Raman (FT-Raman, ultraviolet-visible (UV-VIS and nuclear magnetic resonance (1H- and 13C-NMR were applied. Structures of the molecules were optimized and their structural characteristics were calculated by the density functional theory (DFT using the B3LYP method with 6-311++G** as a basis set. Geometric and magnetic aromaticity indices, atomic charges, dipole moments and energies were also calculated. Theoretical parameters were compared to the experimental characteristics of investigated compounds. Correlations between certain vibrational bands and some metal parameters, such as electronegativity, ionization energy, atomic and ionic radius, were found. The microbial activity of studied compounds was tested against Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Proteus vulgaris and Candida albicans.

  17. Investigation on Clarified Fruit Juice Composition by Using Visible Light Micro-Raman Spectroscopy.

    Science.gov (United States)

    Camerlingo, Carlo; Zenone, Flora; Delfino, Ines; Diano, Nadia; Mita, Damiano Gustavo; Lepore, Maria

    2007-10-03

    Liquid samples of clarified apple and apricot juices at different productionstages were investigated using visible light micro-Raman spectroscopy in order to assessits potential in monitoring fruit juice production. As is well-known, pectin plays a strategicrole in the production of clarified juice and the possibility of using Raman for its detectionduring production was therefore evaluated. The data analysis has enabled the clearidentification of pectin. In particular, Raman spectra of apple juice samples from washedand crushed fruits revealed a peak at 845 cm -1 (typical of pectin) which disappears in theRaman spectra of depectinised samples. The fructose content was also revealed by thepresence of four peaks at 823 cm -1 , 872 cm -1 , 918 cm -1 and 975 cm -1 . In the case of apricotjuice, several Raman fingerprints of β-carotene at 1008, 1159 and 1520 cm -1 were alsohighlighted. Present results resulted interesting for the exclusive use of optical methods forthe quantitative determination of the above-mentioned substances in place of thebiochemical assays generally used for this purpose, which are time consuming and requiredifferent chemical reagents for each of them.

  18. Investigation on Clarified Fruit Juice Composition by Using Visible Light Micro-Raman Spectroscopy

    Directory of Open Access Journals (Sweden)

    Maria Lepore

    2007-10-01

    Full Text Available Liquid samples of clarified apple and apricot juices at different productionstages were investigated using visible light micro-Raman spectroscopy in order to assessits potential in monitoring fruit juice production. As is well-known, pectin plays a strategicrole in the production of clarified juice and the possibility of using Raman for its detectionduring production was therefore evaluated. The data analysis has enabled the clearidentification of pectin. In particular, Raman spectra of apple juice samples from washedand crushed fruits revealed a peak at 845 cm-1 (typical of pectin which disappears in theRaman spectra of depectinised samples. The fructose content was also revealed by thepresence of four peaks at 823 cm-1, 872 cm-1, 918 cm-1 and 975 cm-1. In the case of apricotjuice, several Raman fingerprints of β-carotene at 1008, 1159 and 1520 cm-1 were alsohighlighted. Present results resulted interesting for the exclusive use of optical methods forthe quantitative determination of the above-mentioned substances in place of thebiochemical assays generally used for this purpose, which are time consuming and requiredifferent chemical reagents for each of them.

  19. Raman spectroscopy of white wines.

    Science.gov (United States)

    Martin, Coralie; Bruneel, Jean-Luc; Guyon, François; Médina, Bernard; Jourdes, Michael; Teissedre, Pierre-Louis; Guillaume, François

    2015-08-15

    The feasibility of exploiting Raman scattering to analyze white wines has been investigated using 3 different wavelengths of the incoming laser radiation in the near-UV (325 nm), visible (532 nm) and near infrared (785 nm). To help in the interpretation of the Raman spectra, the absorption properties in the UV-visible range of two wine samples as well as their laser induced fluorescence have also been investigated. Thanks to the strong intensity enhancement of the Raman scattered light due to electronic resonance with 325 nm laser excitation, hydroxycinnamic acids may be detected and analyzed selectively. Fructose and glucose may also be easily detected below ca. 1000 cm(-1). This feasibility study demonstrates the potential of the Raman spectroscopic technique for the analysis of white wines. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Investigation of SOI Raman Lasers for Mid-Infrared Gas Sensing

    Science.gov (United States)

    Passaro, Vittorio M.N.; De Leonardis, Francesco

    2009-01-01

    In this paper, the investigation and detailed modeling of a cascaded Raman laser, operating in the midwave infrared region, is described. The device is based on silicon-on-insulator optical waveguides and a coupled resonant microcavity. Theoretical results are compared with recent experiments, demonstrating a very good agreement. Design criteria are derived for cascaded Raman lasers working as continuous wave light sources to simultaneously sense two types of gases, namely C2H6 and CO2, at a moderate power level of 130 mW. PMID:22408481

  1. Investigation of resonant Raman scattering in type II GaAs/AlAs superlattices

    International Nuclear Information System (INIS)

    Choi, H.

    2001-01-01

    As a consequence of the band alignment in GaAs/AIAs superlattices (SLs) and the indirect nature of bulk AIAs, quantum confinement can be used to engineer a Type II system. This produces an electron population in the AIAs longitudinal (X z ) or transverse (X xy ) zone-edge states, which is separated in both direct and reciprocal space from the hole population in the GaAs zone-centre (Γ) states. This thesis is an investigation of the electronic and vibrational structure of Type II GaAs/AIAs SLs using theoretical models and spectroscopic techniques, with special emphasis on Type II resonant Raman (RR) scattering. The majority of this thesis concerns short-period GaAs/AIAs SLs with X z as the lowest conduction band state. A model of the SL electronic band structure is presented, including the effects of interband Γ-X z mixing and the X-point camel's back structure. Interband mixing makes Γ-X z radiative transitions observable in photoluminescence (PL) and RR experiments. Phonon-assisted transitions from the X z state are also observed in PL experiments. Several of the participating phonon modes are unambiguously identified, in good agreement with recent reports. This thesis presents the first detailed experimental and theoretical study of Type II RR scattering from the incoming channel of the X z -related Type II bandgap. The X z - related Type II incoming RR spectra in the GaAs optic phonon region are compared with the Γ-related Type I outgoing RR spectra within several theoretical models. Thereby, the mechanisms of the Type II RR scattering, the origins of the RR lineshape and the polarisation dependence, are fully explained, clarifying the spectral features observed in the GaAs zone-centre optic phonon region. The Type II resonance also allows the observation of zone boundary (X-point) phonons from intervalley (IV) scattering. A model of the IV electron-phonon interaction involving X conduction band electrons and zone boundary phonons in Type II SLs is presented

  2. FT-Raman and FT-Infrared investigations of archaeological artefacts from Foeni Neolithic site (Banat, Romania

    Directory of Open Access Journals (Sweden)

    Simona Cîntă Pînzaru

    2008-08-01

    Full Text Available An impressive collection of chert artefacts from the Foeni Neolithic archaeological site (Timiş County, Banat region, Romania is hosted by the Banat Museum in Timişoara. A representative set of seven specimens was non-destructively investigated using FT-Raman and ATR-FT-IR spectroscopy. The research was carried out for checking if these readily-available, non-destructive, fast, and cheap methods, which do not require preliminary sample preparation could provide significant information for characterizing the mineral composition of chert artefacts. Based on vibrational data, it was confirmed that the raw material was represented by microcrystalline quartz and moganite, with local concentrations of accessory minerals (calcite, dolomite, and clay minerals. In spite of their wide macroscopic heterogeneity (colour, transparency, based on single point FT-Raman measurements the chert artefacts could not be assigned to distinctive groups of raw silica materials, in order to provide specific arguments for provenance studies. However, the presence of specific accessory minerals (dolomite, illite pointed to distinctive genetic conditions in the case of one lithic material. Sets of measurements (mapping are required for statistically characterizing each artefact specimen. IR data were less significant, due to the rough surface texture of the specimens in contact with the ZnSe crystal of the ATR-FT-IR module. However, illite was identified based solely on its contribution to the IR spectrum. This pioneering study on chert artefacts from Romania based on optical spectroscopic methods shows that there are good premises for a systematic investigation of highly-valuable museum collections, in particular in terms of chert geology.

  3. The joined use of n.i. spectroscopic analyses - FTIR, Raman, visible reflectance spectrometry and EDXRF - to study drawings and illuminated manuscripts

    International Nuclear Information System (INIS)

    Bruni, S.; Guglielmi, V.; Caglio, S.; Poldi, G.

    2008-01-01

    Some art objects being small and very precious prevents conservators and conservation scientists from whatever kind of sampling, so that only completely non-invasive (n.i.) studies are permitted. Besides, also moving the object is sometimes forbidden: this happens for jewels as well as for manuscripts, illuminated codices, drawings and paintings. Some important physical n.i. analyses, such as PIXE and PIGE, therefore cannot be used in many cases. With these limitations, only imaging techniques in X, UV, Visible and IR bands, and a few spectroscopic methods that can be carried out with portable instruments can be applied, i.e. molecular spectroscopies like Fourier transform infrared (FTIR), Raman, UV visible and near IR reflectance spectrometry (UV-Vis-NIR RS) and atomic spectroscopy like energy dispersive X-ray fluorescence (EDXRF). The use of only one or two of these techniques is usually far from giving all the information required to achieve a full characterization of materials used by the artist or during restorations, and to understand some conservative problems of the object. On the contrary, a joined use of n.i. analyses can supply a larger set of data, allowing for cross checks. With this aim we show a fully integrated spectroscopic approach to polychrome objects, and, in particular, to drawings and illuminated manuscripts, using portable instruments, specifically μ-FTIR, μ-Raman, Vis-RS and EDXRF, where also the Raman signal does not suffer fluorescence caused by varnish coating and from binder. We propose the joined use of all these four physical analyses to characterize materials - support, pigments, dyes, binders, etc. - on a complex case: a painted and drawn parchment of the late 15th century, or the beginning of the 16th, partly attributed to Andrea Mantegna. The collected spectroscopic data have been compared to proper spectral databases, some of which specifically realized in our laboratories. Also, mixtures of pigments and their stratigraphical

  4. Nuclear spectroscopic investigations of the decay of /sup 155/Eu

    Energy Technology Data Exchange (ETDEWEB)

    Patt, B H

    1974-01-01

    The investigations carried out on the ..beta..-decay of /sup 155/Eu confirm some decay data of this nucleus and explain a few disagreements on the decay scheme. Using the half-life, the ..beta..-boundary energies and branching ratios, the log ft values of the individual ..beta..-transitions were calculated. Finally, by means of ..beta gamma..-coincidence measurements on the semiconductor spectrometer, the inner partial spectra ..beta../sub 3/ and ..beta../sub 4/ were separated for the first time. Form factor investigations were carried out on these spectra which, despite the high log ft values, confirm the allowed character of these transitions.

  5. Investigation of intervertebral disc degeneration using multivariate FTIR spectroscopic imaging

    NARCIS (Netherlands)

    Mader, Kerstin T.; Peeters, Mirte; Detiger, Suzanne E. L.; Helder, Marco N.; Smit, Theo H.; Le Maitre, Christine L.; Sammon, Chris

    2016-01-01

    Traditionally tissue samples are analysed using protein or enzyme specific stains on serial sections to build up a picture of the distribution of components contained within them. In this study we investigated the potential of multivariate curve resolution-alternating least squares (MCR-ALS) to

  6. Volume properties and spectroscopy: A terahertz Raman investigation of hen egg white lysozyme

    Science.gov (United States)

    Sassi, Paola; Perticaroli, Stefania; Comez, Lucia; Giugliarelli, Alessandra; Paolantoni, Marco; Fioretto, Daniele; Morresi, Assunta

    2013-12-01

    The low frequency depolarized Raman spectra of 100 mg/ml aqueous solutions of hen egg white lysozyme (HEWL) have been collected in the 25-85 °C range. Short and long exposures to high temperatures have been used to modulate the competition between the thermally induced reversible and irreversible denaturation processes. A peculiar temperature evolution of spectra is evidenced under prolonged exposure of the protein solution at temperatures higher than 65 °C. This result is connected to the self-assembling of polypeptide chains and testifies the sensitivity of the technique to the properties of both protein molecule and its surrounding. Solvent free spectra have been obtained after subtraction of elastic and solvent components and assigned to a genuine vibrational contribution of hydrated HEWL. A straight similarity is observed between the solvent-free THz Raman feature and the vibrational density of states as obtained by molecular dynamics simulations; according to this, we verify the relation between this spectroscopic observable and the effective protein volume, and distinguish the properties of this latter respect to those of the hydration shell in the pre-melting region.

  7. Moessbauer spectroscopic investigations of Fe/Mn-Fischer-Tropsch-catalysts

    International Nuclear Information System (INIS)

    Deppe, P.; Papp, H.; Rosenberg, M.

    1986-01-01

    The phase composition of Fe/Mn oxide catalysts of different compositions after 200 h of Fischer-Tropsch synthesis have been investigated by Moessbauer spectroscopy at room temperature, 77 K and 5 K. The final composition of the bulk catalysts depends strongly on the Mn content and the temperature of reduction before the synthesis. Catalytic activity and selectivity are partly correlated to this phase composition. (Auth.)

  8. Mg-doped hydroxyapatite nanoplates for biomedical applications: A surfactant assisted microwave synthesis and spectroscopic investigations

    International Nuclear Information System (INIS)

    Mishra, Vijay Kumar; Bhattacharjee, Birendra Nath; Parkash, Om; Kumar, Devendra; Rai, Shyam Bahadur

    2014-01-01

    Highlights: • Microwave irradiation technique: employed for the synthesis of Mg-HAp nanoplates. • Surfactant (EDTA) assisted synthesis of Mg-HAp. • FT-IR and Raman analysis of functional groups of Mg-HAp. - Abstract: Nanoplates of Mg doped hydroxyapatite (Mg-HAp) were derived successfully and rapidly via microwave irradiation technique. Hydroxyapatite (HAp) is the hard tissues and main inorganic component in mammals. Different nanostructures of HAp exist in different parts of human bone but nanorods are very common due to its intrinsic nature to grow in rode-like structure under physiological as well as under applied ambient conditions in laboratory. On the addition of Mg at very low level (0.06 mol%) in pure HAp results the formation of 2-D plate-like nanostructures rather than rod-like which is the matter of interest. In this attempt our efforts have been focused on the study of effect of Mg incorporation on structural and spectroscopic properties of HAp prepared via microwave irradiation technique. This technique is preferred due to several advantages viz. very fast as well as homogeneous heating, time/energy saving and eco-friendliness. The calcium nitrate tetrahydrate (Ca(NO 3 ) 2 ⋅4H 2 O)) as a source of calcium, magnesium nitrate hexahydrate (Mg(NO 3 ) 2 ⋅6H 2 O) as a source of magnesium, disodium hydrogen phosphate dihydrate (NaH 2 PO 4 ⋅2H 2 O) as a source of phosphorous and sodium ethylene diamine tetra acetate (NaEDTA) as a surfactant were used as starting reagents. Sodium hydroxide (NaOH) pellets were employed to adjust the pH value of final solution. The solution of fixed pH value was kept into the microwave oven generating waves of frequency 2.45 GHz (water absorption frequency) and power 750 W for 8 min. The precipitate thus obtained was washed, centrifuged and then dried at 100 °C for 2 h. Dried powder was then calcined at 700 °C for 2 h. The bright white powder thus obtained was characterized structurally using X-ray diffraction and

  9. Mg-doped hydroxyapatite nanoplates for biomedical applications: A surfactant assisted microwave synthesis and spectroscopic investigations

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Vijay Kumar [Department of Physics, Faculty of Science, Banaras Hindu University, Varanasi 221005 (India); Bhattacharjee, Birendra Nath; Parkash, Om [Department of Ceramic Engineering, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005 (India); Kumar, Devendra, E-mail: devendra.cer@iitbhu.ac.in [Department of Ceramic Engineering, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005 (India); Rai, Shyam Bahadur, E-mail: sbrai49@yahoo.co.in [Department of Physics, Faculty of Science, Banaras Hindu University, Varanasi 221005 (India)

    2014-11-25

    Highlights: • Microwave irradiation technique: employed for the synthesis of Mg-HAp nanoplates. • Surfactant (EDTA) assisted synthesis of Mg-HAp. • FT-IR and Raman analysis of functional groups of Mg-HAp. - Abstract: Nanoplates of Mg doped hydroxyapatite (Mg-HAp) were derived successfully and rapidly via microwave irradiation technique. Hydroxyapatite (HAp) is the hard tissues and main inorganic component in mammals. Different nanostructures of HAp exist in different parts of human bone but nanorods are very common due to its intrinsic nature to grow in rode-like structure under physiological as well as under applied ambient conditions in laboratory. On the addition of Mg at very low level (0.06 mol%) in pure HAp results the formation of 2-D plate-like nanostructures rather than rod-like which is the matter of interest. In this attempt our efforts have been focused on the study of effect of Mg incorporation on structural and spectroscopic properties of HAp prepared via microwave irradiation technique. This technique is preferred due to several advantages viz. very fast as well as homogeneous heating, time/energy saving and eco-friendliness. The calcium nitrate tetrahydrate (Ca(NO{sub 3}){sub 2}⋅4H{sub 2}O)) as a source of calcium, magnesium nitrate hexahydrate (Mg(NO{sub 3}){sub 2}⋅6H{sub 2}O) as a source of magnesium, disodium hydrogen phosphate dihydrate (NaH{sub 2}PO{sub 4}⋅2H{sub 2}O) as a source of phosphorous and sodium ethylene diamine tetra acetate (NaEDTA) as a surfactant were used as starting reagents. Sodium hydroxide (NaOH) pellets were employed to adjust the pH value of final solution. The solution of fixed pH value was kept into the microwave oven generating waves of frequency 2.45 GHz (water absorption frequency) and power 750 W for 8 min. The precipitate thus obtained was washed, centrifuged and then dried at 100 °C for 2 h. Dried powder was then calcined at 700 °C for 2 h. The bright white powder thus obtained was characterized

  10. Terahertz spectroscopic investigation of gallic acid and its monohydrate

    Science.gov (United States)

    Zhang, Bo; Li, Shaoping; Wang, Chenyang; Zou, Tao; Pan, Tingting; Zhang, Jianbing; Xu, Zhou; Ren, Guanhua; Zhao, Hongwei

    2018-02-01

    The low-frequency spectra of gallic acid (GA) and its monohydrate were investigated by terahertz time-domain spectroscopy (THz-TDS) in the range of 0.5 to 4.5 THz. The dehydration process of GA monohydrate was monitored on-line. The kinetic mechanism of the dehydration process was analyzed depending on the THz spectral change at different temperatures. The results indicate that the diffusion of water molecule dominates the speed of the entire dehydration process. Solid-state density functional theory (DFT) calculations of the vibrational modes of both GA and its monohydrate were performed based on their crystalline structures for better interpreting the experimental THz spectra. The results demonstrate that the characterized features of GA mainly originate from the collective vibrations of molecules. And the interactions between GA and water molecules are responsible for THz fingerprint of GA monohydrate. Multi-techniques including differential scanning calorimetry and thermogravimetry (DSC-TG) and powder X-ray diffraction (PXRD) were also carried out to further investigate GA and its monohydrate.

  11. In-vivo morphologic and spectroscopic investigation of Psoriasis

    Science.gov (United States)

    Kapsokalyvas, Dimitrios; Cicchi, Riccardo; Bruscino, Nicola; Alfieri, Domenico; Massi, Daniela; Lotti, Torello; Pavone, Francesco S.

    2011-07-01

    Psoriasis is an autoimmune disease of the skin characterized by hyperkeratosis, hyperproliferation of the epidermis, inflammatory cell accumulation and increased dilatation of dermal papillary blood vessels. Cases of psoriasis were investigated in vivo with optical means in order to evaluate the potential of in vivo optical biopsy. A Polarization Multispectral Dermoscope was employed for the macroscopic observation. Features such as the 'dotted' blood vessels pattern was observed with high contrast. High resolution image sections of the epidermis and the dermis were produced with a custom made Multiphoton Microscope. Imaging extended from the surface of the lesion down to the papillary dermis, at a depth of 200 μm. In the epidermis, a characteristic morphology of the stratum corneum found only in Psoriasis was revealed. Additionally, the cytoplasmic area of the cells in the stratum spinosum layer was found to be smaller than normal. In the dermis the morphological features were more pronounced, where the elongated dermal papillae dominated the papillary layer. Their length exceeds 100μm, which is a far greater value compared to that of healthy skin. These in vivo observations are consistent with the ex vivo histopathological observations, supporting both the applicability and potentiality of multispectral dermoscopy and multiphoton microscopy in the field of in vivo optical investigation and biopsy of skin.

  12. Spectroscopic investigation of Ni speciation in hardened cement paste.

    Science.gov (United States)

    Vespa, M; Dähn, R; Grolimund, D; Wieland, E; Scheidegger, A M

    2006-04-01

    Cement-based materials play an important role in multi-barrier concepts developed worldwide for the safe disposal of hazardous and radioactive wastes. Cement is used to condition and stabilize the waste materials and to construct the engineered barrier systems (container, backfill, and liner materials) of repositories for radioactive waste. In this study, Ni uptake by hardened cement paste has been investigated with the aim of improving our understanding of the immobilization process of heavy metals in cement on the molecular level. X-ray absorption spectroscopy (XAS) coupled with diffuse reflectance spectroscopy (DRS) techniques were used to determine the local environment of Ni in cement systems. The Ni-doped samples were prepared at two different water/cement ratios (0.4, 1.3) and different hydration times (1 hour to 1 year) using a sulfate-resisting Portland cement. The metal loadings and the metal salts added to the system were varied (50 up to 5000 mg/kg; NO3(-), SO4(2-), Cl-). The XAS study showed that for all investigated systems Ni(ll) is predominantly immobilized in a layered double hydroxide (LDH) phase, which was corroborated by DRS measurements. Only a minor extent of Ni(ll) precipitates as Ni-hydroxides (alpha-Ni(OH)2 and beta-Ni(OH)2). This finding suggests that Ni-Al LDH, rather than Ni-hydroxides, is the solubility-limiting phase in the Ni-doped cement system.

  13. Molecular structure, vibrational spectroscopic analysis (IR & Raman), HOMO-LUMO and NBO analysis of anti-cancer drug sunitinib using DFT method

    Science.gov (United States)

    Mıhçıokur, Özlem; Özpozan, Talat

    2017-12-01

    Oxindole and its derivatives have wide applications in different industries such as in synthetic & natural fibers, dyes for hair and plastic materials in addition to their biological importance. In the present study, one of the oxindole derivatives, N-(2-diethylaminoethyl)-5-[(Z)-(5-fluoro-2-oxo-1H-indol-3-ylidene)methyl]-2,4-dimethyl-1H-pyrrole-3-carboxamide (Sunitinib), which is used as an anti-cancer drug, was investigated in terms of structural, vibrational spectroscopic and theoretical analysis. The calculations have been performed for gaseous, aqueous and DMSO phases, respectively. Potential Energy Surface (PES) scan has been carrried out to obtain the most stable structures of all the phases of the title molecule using B3LYP/6-31G(d,p) level and the geometrical variations among them are discussed. The solvent effect for Sunitinib in aqueous and DMSO phases have been performed by means of the self-consistent recognition reaction field (SCRF) method as implemented in the integral equation formalism polarized continuum model (IEFPCM). On the other hand, NBO analysis has been carried out to understand probable hydrogen bonding sites and charge transfers. Additionally, the HOMO and the LUMO energies are calculated using B3LYP/6-31G(d,p) to determine the intra molecular charge transfers (ICT) within the molecule and the kinetic stabilities for each phases. The molecular electrostatic potential surface (MESP) has been plotted over the optimized structure to estimate the reactive sites of electrophilic and nucleophilic attacks regarding Sunitinib molecule. The potential energy distribution (PED) has been calculated using VEDA4 program and vibrational assignments of the experimental spectra (IR & Raman) have been elucidated by means of the calculated vibrational spectra. The observed vibrational spectra of Sunitinib is compared with the calculated spectra obtained by using B3LYP functional both with 6-31G(d,p) and 6-311++G(d,p) basis sets. Theoretical results

  14. Photometric and spectroscopic investigation of carbon stars. 1

    International Nuclear Information System (INIS)

    Vetesnik, M.

    1984-01-01

    The photoelectric light curves for carbon star UX Dra were derived in three colours and are discussed. Their shape shows a regular alternation of one deep and one shallow minima, which suggest the light curve of an eclipsing binary. The period variations of the star are analyzed on the basis of old photographic observations. The radial velocity curve of the star based on the measurements of the Swan molecular bands C 2 (1,0) and C 2 (0,1) exhibits a minimum preceding the primary light minima by about 0.15 P. The period P is 336 days, i.e. twice the mean period observed so far for the light variations of the star. The total absorption in the Swan molecular bands in dependence on the light phase of the star is investigated. The period of variability in molecular absorption equals the period of the radial velocity curve. Three possible mechanisms are considered to explain the light, radial velocity and molecular absorption chanqes of the star: radial pulsations, rotation of a heterogeneous single star, and occultations of two revolving components in a binary system. (author)

  15. Laser spectroscopic investigation of singly and doubly charged thorium ions

    Energy Technology Data Exchange (ETDEWEB)

    Thielking, Johannes; Meier, David-Marcel; Glowacki, Przemyslaw; Okhapkin, Maksim V.; Peik, Ekkehard [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)

    2017-07-01

    The {sup 229}Th isotope possesses a unique, low-energy nuclear isomeric state at about 7.8(5) eV. This fact has stimulated the development of novel ideas in the borderland between atomic and nuclear physics, for example the use as an optical nuclear clock. Since the required precise information on the isomer energy is not yet available, it is intensely searched for using different experimental approaches. For the excitation of the nuclear isomer via electronic bridge or NEET processes, we plan to use two-photon laser excitation of high-lying electronic levels in Th{sup +}. We recently expanded our search range to higher energies and measured 38 previously unknown energy levels in the range from 7.8 eV to 8.7 eV. We also prepare to study the nuclear structure of the isomeric state in cooperation with the Maier-Leibnitz-Laboratorium at LMU Munich, using trapped recoil ions, where the isomeric state is populated via α-decay from {sup 233}U. For this purpose we investigate the hyperfine structure of suitable transitions of Th{sup 2+}.

  16. Bonding of radioactive contamination. III. Auger electron spectroscopic investigation

    International Nuclear Information System (INIS)

    Rankin, W.N.; Whitkop, P.G.

    1983-01-01

    The mechanisms by which radioactive contamination would be bonded to a DWPF canister surface are being investigated. Tests with low pressure water and air-injected water decontamination of radioactive specimens showed that bonding of contamination increases rapidly with postoxidation temperature. Even with the least severe temperature conditions expected on the waste glass canister, bonding is so great that decontamination cannot be affected by water-only techniques. A preoxidation film increased rather than decreased bonding. This memorandum describes detailed surface analyses of coupons simulating DWPF canister surfaces. Based on this examination we conclude: contamination will be dispersed throughout the oxide film on DWPF canisters. Contamination is concentrated at the surface, decreasing farther into the oxide film; some samples contain sludge contamination at the steel/oxide interface. This was not the case for semi-volatile (Cs 2 O) contamination; in samples with contamination at the steel/oxide interface, at least 80% of the contamination is usually in the oxide layer; no difference in contamination dispersion between preoxidized and non-preoxidized samples was found; and postoxidation atmosphere had no effect on the contamination dispersion within the oxide layer. 6 references, 9 figures

  17. Surface-enhanced Raman spectroscopic study of DNA and 6-mercapto-1-hexanol interactions using large area mapping

    DEFF Research Database (Denmark)

    Frøhling, Kasper Bayer; Alstrøm, Tommy Sonne; Bache, Michael

    2016-01-01

    intensities and peak positions it is possible to directly inspect the interplay between DNA and 6-mercapto-1-hexanol on gold covered nanopillars. It is demonstrated that optimised functionalization parameters can be extracted from the Raman spectra directly. Using the peak-fitting approach it is possible...

  18. Deep-UV Raman spectroscopic analysis of structure and dissolution rates of silica-rich sodium borosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, Eric M [ORNL; WindischJr., Charles F. [Pacific Northwest National Laboratory (PNNL); Burton, Sarah D. [Pacific Northwest National Laboratory (PNNL); Bovaird, Chase C. [Pacific Northwest National Laboratory (PNNL)

    2010-01-01

    As part of ongoing studies to evaluate relationships between structure and rates of dissolution of silicate glasses in aqueous media, sodium borosilicate glasses of composition Na2O xB2O3 (3 x)SiO2, with x 1 (Na2O/B2O3 ratio 1), were analyzed using deep-UV Raman spectroscopy. Results were quantified in terms of the fraction of SiO4 tetrahedra with one non-bridging oxygen (Q3) and then correlated with Na2O and B2O3 content. The Q3 fractionwas found to increase with increasing Na2O content, in agreement with studies on related glasses, and, as long as the value of x was not too high, this contributed to higher rates of dissolution in single pass flow-through testing. In contrast, dissolution rates were less strongly determined by the Q3 fraction when the value of x was near unity, and appeared to grow larger upon further reduction of the Q3 fraction. Results were interpreted to indicate the increasingly important role of network hydrolysis in the glass dissolution mechanism as the BO4 tetrahedron replaces the Q3 unit as the charge-compensating structure for Na+ ions. Finally, the use of deep-UV Raman spectroscopy was found to be advantageous in studying finely powdered glasses in cases where visible Raman spectroscopy suffered from weak Raman scattering and fluorescence interference.

  19. Longitudinal Raman Spectroscopic Observation of Skin Biochemical Changes due to Chemotherapeutic Treatment for Breast Cancer in Small Animal Model

    Directory of Open Access Journals (Sweden)

    Myeongsu Seong

    2017-01-01

    Full Text Available The cancer field effect (CFE has been highlighted as one of indirect indications for tissue variations that are insensitive to conventional diagnostic techniques. In this research, we had a hypothesis that chemotherapy for breast cancer would affect skin biochemical compositions that would be reflected by Raman spectral changes. We used a fiber-optic probe-based Raman spectroscopy to perform preliminary animal experiments to validate the hypothesis. Firstly, we verified the probing depth of the fiber-optic probe (~800 μm using a simple intravenous fat emulsion-filled phantom having a silicon wafer at the bottom inside a cuvette. Then, we obtained Raman spectra during breast cancer treatment by chemotherapy from a small animal model in longitudinal manner. Our results showed that the treatment causes variations of biochemical compositions in the skin. For further validation, the Raman spectra will have to be collected from more populations and spectra will need to be compared with immunohistochemistry of the breast tissue.

  20. Raman Spectroscopic Analysis of Biochemical Changes in Individual Triglyceride-Rich Lipoproteins in the Pre- and Postprandial State

    Energy Technology Data Exchange (ETDEWEB)

    Chan, J; Motton, D; Rutledge, J; Keim, N; Huser, T

    2004-09-13

    Individual triglyceride-rich lipoprotein (TGRL) particles derived from human volunteers are non-destructively analyzed by laser tweezers Raman microspectroscopy and information on their composition and distribution is obtained. The Raman signature of single optically trapped very low-density lipoproteins (VLDL), a subclass of TGRL, which play an important role in cardiovascular disease, exhibits distinct peaks associated with molecular vibrations of fatty acids, proteins, lipids, and structural rearrangements of lipids. Our analysis of pre- and postprandial VLDL exhibits the signature of biochemical changes in individual lipoprotein particles following the consumption of meals. Interaction of VLDL with endothelium leads to the breakdown of complex triacylglycerols and the formation of a highly ordered core of free saturated fatty acids in the particle. A particle distribution analysis reveals trends in the degree to which this process has occurred in particles at different times during the postprandial period. Differences in particle distributions based on the different ratios of polyunsaturated to saturated fats in the consumed meals are also easily discerned. Individual lipoprotein particles hydrolyzed in-vitro through addition of lipoprotein lipase (LpL) exhibit strikingly similar changes in their Raman spectra. These results demonstrate the feasibility of monitoring the dynamics of lipid metabolism of individual TGRL particles as they interact with LpL in the endothelial cell wall using Raman spectroscopy.

  1. Predicting meat quality traits of ovine m. semimembranosus, both fresh and following freezing and thawing, using a hand held Raman spectroscopic device.

    Science.gov (United States)

    Fowler, Stephanie M; Schmidt, Heinar; van de Ven, Remy; Wynn, Peter; Hopkins, David L

    2015-10-01

    Complementary studies were conducted to determine the potential for a Raman spectroscopic hand held device to predict meat quality traits of fresh lamb m. semimembranosus (topside) after ageing and freezing/thawing. Spectra were collected from 80 fresh muscles at 24h and 5d PM, another 80 muscles were measured at 24h, 5d and following freezing/thawing. Shear force, cooking loss, sarcomere length, colour, particle size, collagen content, pH24, pHu, purge and thaw loss were also measured. Results indicated a potential to predict pHu (R(2)cv=0.59), pH24 (R(2)cv=0.48) and purge (R(2)cv=0.42) using spectra collected 24h PM. L* could be predicted using spectra collected 24h (R(2)cv=0.33) or 5d PM (R(2)cv=0.33). This suggests that Raman spectroscopy is suited to identifying carcases which deviate from the normal metabolic processes and related meat quality traits. Copyright © 2015. Published by Elsevier Ltd.

  2. Effects of hydrogen peroxide bleaching strips on tooth surface color, surface microhardness, surface and subsurface ultrastructure, and microchemical (Raman spectroscopic) composition.

    Science.gov (United States)

    Duschner, Heinz; Götz, Hermann; White, Donald J; Kozak, Kathleen M; Zoladz, James R

    2006-01-01

    This study examined the effects of hydrogen peroxide tooth bleaching strips on the surface hardness and morphology of enamel and the ultrastructure and chemical composition of enamel and dentin in vitro. Sound human molars were ground and polished to prepare a uniform substrate for bleaching treatments. A cycling treatment methodology was employed which alternated ex vivo human salivary exposures with bleaching treatments under conditions of controlled temperature and durations of treatment. Bleaching treatments included commercial Crest Whitestrips bleaching strips, which utilize hydrogen peroxide in a gel as the in situ bleaching source at 6.0 and 6.5% concentrations of H2O2. Control treatments included an untreated group. Crest Whitestrips bleaching included treatment exposures simulating 2x the recommended clinical exposures (28 hours bleaching). Surface color measurements were taken prior to and following bleaching to ensure tooth bleaching activity. The effects of bleach on physical properties of enamel were assessed with microhardness measures. Ultrastructural effects were classified by surface and subsurface confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) techniques. In addition, the effects of bleaching on tooth microchemical composition was studied in different tooth regions by coincident assessment of Raman spectroscopic signature. Color assessments confirmed significant ex vivo tooth bleaching by Whitestrips. Surface microhardness and SEM measures revealed no deleterious effects on the enamel surfaces. CLSM micromorphological assessments supported the safety of hydrogen peroxide bleaching strips both on surface and subsurface enamel, DEJ, and dentin ultrastructure. Raman spectroscopy analysis demonstrated no obvious effects of bleaching treatments on the microchemical composition of enamel and dentin. These results confirm that tooth bleaching with hydrogen peroxide whitening strips does not produce changes in surface

  3. HF-EPR, Raman, UV/VIS light spectroscopic, and DFT studies of the ribonucleotide reductase R2 tyrosyl radical from Epstein-Barr virus.

    Directory of Open Access Journals (Sweden)

    Ane B Tomter

    Full Text Available Epstein-Barr virus (EBV belongs to the gamma subfamily of herpes viruses, among the most common pathogenic viruses in humans worldwide. The viral ribonucleotide reductase small subunit (RNR R2 is involved in the biosynthesis of nucleotides, the DNA precursors necessary for viral replication, and is an important drug target for EBV. RNR R2 generates a stable tyrosyl radical required for enzymatic turnover. Here, the electronic and magnetic properties of the tyrosyl radical in EBV R2 have been determined by X-band and high-field/high-frequency electron paramagnetic resonance (EPR spectroscopy recorded at cryogenic temperatures. The radical exhibits an unusually low g₁-tensor component at 2.0080, indicative of a positive charge in the vicinity of the radical. Consistent with these EPR results a relatively high C-O stretching frequency associated with the phenoxyl radical (at 1508 cm⁻¹ is observed with resonance Raman spectroscopy. In contrast to mouse R2, EBV R2 does not show a deuterium shift in the resonance Raman spectra. Thus, the presence of a water molecule as a hydrogen bond donor moiety could not be identified unequivocally. Theoretical simulations showed that a water molecule placed at a distance of 2.6 Å from the tyrosyl-oxygen does not result in a detectable deuterium shift in the calculated Raman spectra. UV/VIS light spectroscopic studies with metal chelators and tyrosyl radical scavengers are consistent with a more accessible dimetal binding/radical site and a lower affinity for Fe²⁺ in EBV R2 than in Escherichia coli R2. Comparison with previous studies of RNR R2s from mouse, bacteria, and herpes viruses, demonstrates that finely tuned electronic properties of the radical exist within the same RNR R2 Ia class.

  4. Raman Investigation of Temperature Profiles of Phospholipid Dispersions in the Biochemistry Laboratory

    Science.gov (United States)

    Craig, Norman C.

    2015-06-01

    The temperature dependence of self-assembled, cell-like dispersions of phospholipids is investigated with Raman spectroscopy in the biochemistry laboratory. Vibrational modes in the hydrocarbon interiors of phospholipid bilayers are strongly Raman active, whereas the vibrations of the polar head groups and the water matrix have little Raman activity. From Raman spectra increases in fluidity of the hydrocarbon chains can be monitored with intensity changes as a function of temperature in the CH-stretching region. The experiment uses detection of scattered 1064-nm laser light (Nicolet NXR module) by a Fourier transform infrared spectrometer (Nicolet 6700). A thermoelectric heater-cooler device (Melcor) gives convenient temperature control from 5 to 95°C for samples in melting point capillaries. Use of deuterium oxide instead of water as the matrix avoids some absorption of the exciting laser light and interference with intensity observations in the CH-stretching region. Phospholipids studied range from dimyristoylphosphotidyl choline (C14, transition T = 24°C) to dibehenoylphosphotidyl choline (C22, transition T = 74°C).

  5. Investigation of L(+)-Ascorbic Acid with Raman Spectroscopy in Visible and UV Light

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    2015-01-01

    Abstract: Raman spectroscopy investigations of l(+)-ascorbic acid and its mono- and di-deprotonated anions (AH(-) and A(2-)) are reviewed and new measurements reported with several wavelengths, 229, 244, 266, 488, and 532nm. Results are interpreted, assisted by new DFT/B3LYP quantum chemical calc......). Relatively weak preresonance enhancement was seen for A(2-) when excitation was done with 229nm UV light, allowing water bands to become observable as for normal visible light Raman spectra....... calculations with 6-311++G(d,p) basis sets for several conformations of ascorbic acid and the anions. Raman spectra were measured during titration with NaOH base in an oxygen-poor environment to avoid fluorescence when solutions were alkaline. The ultraviolet (UV) absorption band for ascorbic acid in aqueous......cm(-1). Finally, for the ascorbate di-anion, absorption was found at similar to 298.4nm with molar absorptivity of similar to 7,000 L mol(-1) cm(-1) and below similar to 220nm. With UV light (244 and 266nm), strongly basic solutions gave pronounced Raman resonance enhancement at similar to 1556cm(-1...

  6. Investigation of domain walls in PPLN by confocal raman microscopy and PCA analysis

    Science.gov (United States)

    Shur, Vladimir Ya.; Zelenovskiy, Pavel; Bourson, Patrice

    2017-07-01

    Confocal Raman microscopy (CRM) is a powerful tool for investigation of ferroelectric domains. Mechanical stresses and electric fields existed in the vicinity of neutral and charged domain walls modify frequency, intensity and width of spectral lines [1], thus allowing to visualize micro- and nanodomain structures both at the surface and in the bulk of the crystal [2,3]. Stresses and fields are naturally coupled in ferroelectrics due to inverse piezoelectric effect and hardly can be separated in Raman spectra. PCA is a powerful statistical method for analysis of large data matrix providing a set of orthogonal variables, called principal components (PCs). PCA is widely used for classification of experimental data, for example, in crystallization experiments, for detection of small amounts of components in solid mixtures etc. [4,5]. In Raman spectroscopy PCA was applied for analysis of phase transitions and provided critical pressure with good accuracy [6]. In the present work we for the first time applied Principal Component Analysis (PCA) method for analysis of Raman spectra measured in periodically poled lithium niobate (PPLN). We found that principal components demonstrate different sensitivity to mechanical stresses and electric fields in the vicinity of the domain walls. This allowed us to separately visualize spatial distribution of fields and electric fields at the surface and in the bulk of PPLN.

  7. Raman investigation of GaP–Si interfaces grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Bondi, A.; Cornet, C.; Boyer, S.; Nguyen Thanh, T.; Létoublon, A.; Pedesseau, L.; Durand, O. [Université Européenne de Bretagne, INSA, FOTON, UMR CNRS 6082, 20 Avenue des Buttes de Coësmes, F-35708 Rennes (France); Moreac, A. [Institut de Physique de Rennes, UMR-CNRS n°6251, Université Rennes1, Campus de Beaulieu — 35042 Rennes cedex (France); Ponchet, A. [CEMES, UPR CNRS 8011, F-31055 Toulouse (France); Le Corre, A. [Université Européenne de Bretagne, INSA, FOTON, UMR CNRS 6082, 20 Avenue des Buttes de Coësmes, F-35708 Rennes (France); Even, J., E-mail: jacky.even@insa.rennes.fr [Université Européenne de Bretagne, INSA, FOTON, UMR CNRS 6082, 20 Avenue des Buttes de Coësmes, F-35708 Rennes (France)

    2013-08-31

    Raman spectroscopy was used to investigate the residual strain in thin GaP layers deposited on Si substrates by molecular beam epitaxy. Different growth conditions were used to obtain a clean GaP–Si interface, including migration enhanced epitaxy. The strain induced Raman shifts of the longitudinal and the transverse optical GaP lattice modes were analyzed. The effects of crystalline defects are discussed, supported by high resolution transmission electron microscopy and X-ray scattering studies. Finally, Raman Spectroscopy reveals the presence of disorder (or surface)-activated optical phonons. This result is discussed in the light of surface morphology analyses. - Highlights: ► GaP thin layers grown by molecular beam epitaxy on Si substrates. ► Strain-induced Raman shifts of the optical GaP modes are analyzed. ► Simulation of optical GaP modes by density functional perturbation theory. ► Comparison with X-ray diffraction and electron and scanning probe microscopy data.

  8. Investigation by Raman Spectroscopy of the Decomposition Process of HKUST-1 upon Exposure to Air

    Directory of Open Access Journals (Sweden)

    Michela Todaro

    2016-01-01

    Full Text Available We report an experimental investigation by Raman spectroscopy of the decomposition process of Metal-Organic Framework (MOF HKUST-1 upon exposure to air moisture (T=300 K, 70% relative humidity. The data collected here are compared with the indications obtained from a model of the process of decomposition of this material proposed in literature. In agreement with that model, the reported Raman measurements indicate that for exposure times longer than 20 days relevant irreversible processes take place, which are related to the occurrence of the hydrolysis of Cu-O bonds. These processes induce small but detectable variations of the peak positions and intensities of the main Raman bands of the material, which can be related to Cu-Cu, Cu-O, and O-C-O stretching modes. The critical analyses of these changes have permitted us to obtain a more detailed description of the process of decomposition taking place in HKUST-1 upon interaction with moisture. Furthermore, the reported Raman data give further strong support to the recently proposed model of decomposition of HKUST-1, contributing significantly to the development of a complete picture of the properties of this considerable deleterious effect.

  9. Luminescence and micro-Raman investigations on inclusions of unusual habit in chrysoprase from Turkey

    International Nuclear Information System (INIS)

    Ayvacıklı, M.; Garcia-Guinea, J.; Jorge, A.; Akalın, İ.; Kotan, Z.; Can, N.

    2012-01-01

    Chemical analyses performed on chrysoprase from Turkey have shown many trace elements as well as rare earth impurities. Quantitative chemical analyses of inclusions in minerals can improve our understanding of the chemistry of surface. The environmental scanning electron microscope (ESEM) with an attached X-ray energy dispersive system (EDS) is capable of producing rapid and accurate major element chemical analyses of individual inclusions in crystals larger than about 30 μm in diameter. The samples were examined with lifetime-resolved and spatially-resolved cathodoluminescence (CL), and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Spatially resolved CL results at room temperature were recorded for two different areas. Bulk area displays with low CL emission and pores contain iron phases such as chromite, hematite and anatase which cause the green color. For the raw data in the lifetime resolved CL spectrum, at least three broad emission bands were detected in a yellow band of the highest intensity at about 550 nm, a weaker orange band at about 650 nm, and a red band at 720 nm. It is assumed that there are links between the CL emissions and the presence of some transition metal and REE elements, but it is obvious that all trace elements do not play a direct role. Micro-Raman measurements were performed on chrysoprase and these showed a characteristic intensive Raman band peaked at 464 cm −1 which can be inferred to ν 2 doubly symmetric bending mode of [SiO 4 /M] centers. Raman spectrum of all inclusions found in the material are also given and discussed in detail. - Highlights: ► Luminescence and Raman investigations of Chrysoprase. ► Characteristic intensive Raman band peaked at 464 cm −1 . ► Ironed phases such as chromite, hematite and anatase.

  10. Infrared, Raman and Magnetic Resonance Spectroscopic study of SiO.sub.2./sub.:C nanopowders

    Czech Academy of Sciences Publication Activity Database

    Savchenko, Dariia; Vorlíček, Vladimír; Kalabukhova, E.; Sitnikov, A.; Vasin, A.; Kysil, D.; Sevostianov, S.; Tertykh, V.; Nazarov, A.

    2017-01-01

    Roč. 12, č. 1 (2017), 1-12, č. článku 292. ISSN 1931-7573 R&D Projects: GA MŠk LO1409; GA MŠk LM2015088 Institutional support: RVO:68378271 Keywords : EPR * Raman spectroscopy * carbosil * carbon nanodots * carbon-related defects Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.)

  11. Raman spectroscopic study of the aging and nitration of actinide processing anion-exchange resins in concentrated nitric acid

    International Nuclear Information System (INIS)

    Buscher, C. T.; Donohoe, R. J.; Mecklenburg, S. L.; Berg, J. M.; Tait, C. D.; Huchton, K. M.; Morris, D. E.

    1999-01-01

    Degradation of two types of anion exchange resins, Dowex 11 and Reillex HPQ, from the action of concentrated nitric acid (4 to 12 M) and radiolysis [from depleted uranium as UO 2 2+ nitrate species and 239 Pu as Pu(IV) nitrate species] was followed as a function of time with Raman vibrational spectroscopy. Elevated temperatures (∼50 degree sign C) were used in the absence of actinide metal loading to simulate longer exposures of the resin to a HNO 3 process stream and waste storage conditions. In the absence of actinide loading, only minor changes in the Dowex resin at acid concentrations ≤10 M were observed, while at 12 M acid concentration, the emergence of a Raman peak at 1345 cm-1 indicates the addition of nitro functional groups to the resin. Similar studies with the Reillex resin show it to be more resistant to nitric acid attack at all acid concentrations. Incorporation of weakly radioactive depleted uranium as the UO 2 2+ nitrate species to the ion-exchange sites of Dowex 11 under differing nitric acid concentrations (6 to 12 M) at room temperature showed no Raman evidence of resin degradation or nitration, even after several hundred days of contact. In contrast, Raman spectra for Dowex 11 in the presence of 239 Pu as Pu(IV) nitrate species reveal numerous changes indicating resin alterations, including a new mode at 1345 cm-1 consistent with a Pu(IV)-nitrate catalyzed addition of nitro groups to the resin backbone. (c) 2000 Society for Applied Spectroscopy

  12. Deep-UV Raman spectroscopic analysis of structure and dissolution rates of silica-rich sodium borosilicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Windisch, Charles F.; Pierce, Eric M.; Burton, Sarah D.; Bovaird, Chase C.

    2011-03-24

    As part of ongoing studies to evaluate the relationships between structural variations in silicate glasses and rates of glass dissolution in aqueous media, molecular structures present in sodium borosilicate glasses of composition Na2O.xB2O3.(3-x)SiO2, with x 1 (Na2O/B2O3 ratio 1), were analyzed using deep-UV Raman spectroscopy. The results were quantified in terms of the fraction of SiO4 tetrahedra with one non-bridging oxygen (Q3) and then correlated with Na2O and B2O3 content. Increasing Na2O was found to raise the fraction of Q3 units in the glasses systematically, in agreement with studies on related glasses, and, as long as the value of x was not too high, contribute to higher rates of dissolution in single pass flow-through testing. The finding was obtained across more than one series of silica-rich glasses prepared for independent dissolution studies. In contrast, dissolution rates were less strongly determined by the Q3 fraction when the value of x was near unity and appeared to grow larger upon further reduction of the Q3 fraction. The results were interpreted to indicate the increasingly important role of network hydrolysis in the glass dissolution mechanism as the BO4 tetrahedron replaces the Q3 unit as the charge-compensating structure for Na+ ions. Finally, the use of deep-UV Raman spectroscopy was found to be advantageous in studying finely powdered glasses in cases where visible Raman spectroscopy suffered from weak Raman scattering and fluorescence interference.

  13. Raman spectroscopic analysis of oral squamous cell carcinoma and oral dysplasia in the high-wavenumber region

    Science.gov (United States)

    Carvalho, Luis Felipe C. S.; Bonnier, Franck; O'Callaghan, Kate; O'Sullivan, Jeff; Flint, Stephen; Neto, Lazaro P. M.; Soto, Cláudio A. T.; dos Santos, Laurita; Martin, Airton A.; Byrne, Hugh J.; Lyng, Fiona M.

    2015-06-01

    Raman spectroscopy can provide a molecular-level signature of the biochemical composition and structure of cells with excellent spatial resolution and could be useful to monitor changes in composition for early stage and non-invasive cancer diagnosis, both ex-vivo and in vivo. In particular, the fingerprint spectral region (400-1,800 cm-1) has been shown to be very promising for optical biopsy purposes. However, limitations to discrimination of dysplastic and inflammatory processes based on the fingerprint region still persist. In addition, the Raman spectral signal of dysplastic cells is one important source of misdiagnosis of normal versus pathological tissues. The high wavenumber region (2,800-3,600 cm-1) provides more specific information based on N-H, O-H and C-H vibrations and can be used to identify the subtle changes which could be important for discrimination of samples. In this study, we demonstrate the potential of the highwavenumber spectral region by collecting Raman spectra of nucleoli, nucleus and cytoplasm from oral epithelial cancer (SCC-4) and dysplastic (DOK) cell lines and from normal oral epithelial primary cells, in vitro, which were then analyzed by area under the curve as a method to discriminate the spectra. In this region, we will show the discriminatory potential of the CH vibrational modes of nucleic acids, proteins and lipids. This technique demonstrated more efficient discrimination than the fingerprint region when we compared the cell cultures.

  14. FT-Raman spectroscopic characterization of enamel surfaces irradiated with Nd:YAG and Er:YAG lasers

    Directory of Open Access Journals (Sweden)

    Sima Shahabi

    2016-12-01

    Full Text Available Background. Despite recent advances in dental caries prevention, caries is common and remains a serious health problem. Laser irradiation is one of the most common methods in preventive measures in recent years. Raman spectroscopy technique is utilized to study the microcrystalline structure of dental enamel. In this study, FT-Raman spectroscopy was used to evaluate chemical changes in enamel structure irradiated with Nd:YAG and Er:YAG lasers. Methods. We used 15 freshly-extracted, non-carious, human molars that were treated as follows: No treatment was carried out in group A (control group; Group B was irradiated with Er:YAG laser for 10 seconds under air and water spray; and Group C was irradiated with Nd:YAG laser for 10 seconds under air and water spray. After treatment, the samples were analyzed by FT-Raman spectroscopy. Results. The carbonate content evaluation with regard to the integrated area under the curve (1065/960 cm–1 exhibited a significant reduction in its ratio in groups B and C. The organic content (2935/960 cm-1 area exhibited a significant decrease after laser irradiation in group B and C. Conclusion. The results showed that the mineral and organic matrices of enamel structure were affected by laser irradiation; therefore, it might be a suitable method for caries prevention.

  15. Quantitative investigation of Raman selection rules and validation of the secular equation for trigonal LiNbO3

    International Nuclear Information System (INIS)

    Pezzotti, Giuseppe; Hagihara, Hirofumi; Zhu Wenliang

    2013-01-01

    Some theoretical aspects of the vibrational behaviour of trigonal lithium niobate (LiNbO 3 ) are studied and discussed in detail based on spectroscopic experimental assessments. Polarized Raman spectroscopy is systematically applied to retrieve the fundamental parameters governing the dependence of Raman intensity on crystallographic orientation, through quantitating the complete set of individual elements for the second-rank Raman tensors of the LiNbO 3 cell (C 3v (3m) point group, R3c space group). Moreover, computational algorithms are also explicitly constructed to describe the spectral shifts of the selected Raman bands when subjected to unknown stress fields. Accordingly, we have experimentally confirmed the validity of the secular equation for the trigonal cell and quantitatively substantiated its application through the determination of the full set of phonon deformation potentials for seven independent bands among those available in the LiNbO 3 vibrational spectrum. Finally, a brief discussion is offered about the significance of the presented characterizations in the technological field of LiNbO 3 devices, including the newly shown possibility of quantitatively and concurrently unfolding from polarized Raman spectra both crystallographic and mechanical information in their vectorial and tensorial nature, respectively. (paper)

  16. Some experiences with absorption, phonon Raman, and luminescence spectroscopic probes of crystal structure of f-element compounds

    International Nuclear Information System (INIS)

    Peterson, J.R.

    1992-01-01

    Structural information is crucial to the study and understanding of the basic chemical properties of the f elements. X-ray diffraction (XRD) techniques are usually used to obtain crystal structure information. However, the transuranium (5f) elements, because of their radioactivity and limited availability, present problems for standard XRD analysis. For some time now we have been developing and using various spectroscopic probes of crystal structure; an overview of our research in this area is presented here

  17. Synthesis, spectroscopic investigations, DFT studies, molecular docking and antimicrobial potential of certain new indole-isatin molecular hybrids: Experimental and theoretical approaches

    Science.gov (United States)

    Almutairi, Maha S.; Zakaria, Azza S.; Ignasius, P. Primsa; Al-Wabli, Reem I.; Joe, Isaac Hubert; Attia, Mohamed I.

    2018-02-01

    Indole-isatin molecular hybrids 5a-i have been synthesized and characterized by different spectroscopic methods to be evaluated as new antimicrobial agents against a panel of Gram positive bacteria, Gram negative bacteria, and moulds. Compound 5h was selected as a representative example of the prepared compounds 5a-i to perform computational investigations. Its vibrational properties have been studied using FT-IR and FT-Raman with the aid of density functional theory approach. The natural bond orbital analysis as well as HOMO and LUMO molecular orbitals investigations of compound 5h were carried out to explore its possible intermolecular delocalization or hyperconjugation and its possible interactions with the target protein. Molecular docking of compound 5h predicted its binding mode with the fungal target protein.

  18. Microstructure and spectroscopic investigations of calcium zinc bismuth phosphate glass ceramics doped with manganese ions

    Science.gov (United States)

    Suneel Kumar, A.; Sambasiva Rao, M. V.; Chinna Ram, G.; Krishna Rao, D.

    2018-01-01

    Multi-component 10CaF2-20ZnO-(15 - x)Bi2O3-55P2O5:xMnO (0 ≤ x ≤ 2.5) glass ceramics were synthesised by melt quenching technique and heat treatment. The prepared glass ceramics were characterised by XRD, DTA, EDS and SEM. Spectroscopic studies such as optical absorption, EPR, FTIR and Raman were also carried out on these glass ceramics. The XRD and SEM studies have indicated that ceramic samples contain well defined and randomly distributed grains of different crystalline phases. The observed increase of enthalpy from DTA patterns up to 1 mol% of MnO indicates that the crystallisation starts initially from the surface of the material then gradually it is extended to the volume of the material and this influence is meagre at higher concentrations of MnO. The absorption spectra of manganese doped glass ceramics have exhibited two types of conventional bands; one due to Mn2+ ions and other due to Mn3+ ions. The EPR spectra of MnO doped glass ceramics showed a resonance signal around g2 = 2.023 with a six line hyperfine structure and another signal at about g1 = 4.314. The relative intensity and half-width of these two signals are observed to increase with the increase in the concentration of manganese ions up to 1 mol% beyond this concentration it is found to decrease. Such observation indicates the conversion of part of Mn2+ ions into Mn3+ ions in the glass ceramic matrix. The observed increase in the intensity of symmetrical structural units at the expense of asymmetrical structural units from the FTIR and Raman spectra at higher concentration of MnO indicating that Mn2+ ions occupy the network forming positions in the glass ceramic structure.

  19. A combined Raman spectroscopic and theoretical investigation of fundamental vibrational bands of furfuryl alcohol (2-furanmethanol)

    DEFF Research Database (Denmark)

    Barsberg, S.; Berg, Rolf W.

    2006-01-01

    . study of FA in weakly interacting environments. It is the first study of FA vibrational properties based on d. functional theory (DFT/B3LYP), and a recently proposed hybrid approach to the calcn. of fundamental frequencies, which also includes an anharmonic contribution. FA occupies five different...

  20. Next generation in-situ optical Raman sensor for seawater investigations

    Science.gov (United States)

    Kolomijeca, A.; Kwon, Y.-H.; Ahmad, H.; Kronfeldt, H.-D.

    2012-04-01

    We introduce the next generation of optical sensors based on a combination of surfaced enhanced Raman scattering (SERS) and shifted excitation Raman difference spectroscopy (SERDS) suited for investigations of tiny concentrations of pollutions in the seawater. First field measurements were carried out in the Arctic area which is of global interest since it is more affected by global warming caused climatic changes than any other areas of our planet and it is a recipient for many toxic organic pollutants. A significant long-range atmospheric transport of pollutants to Svalbard is mainly originated from industrialized countries in Europe and North America during the last decades. Therefore, the main interest is to investigate the Arctic water column and also the sediments. Standard chemical methods for water/sediment analysis are extremely accurate but complex and time-consuming. The primary objective of our study was to develop a fast response in-situ optical sensor for easy to use and quick analysis. The system comprises several components: a handheld measurement head containing a 671 nm microsystem diode laser and the Raman optical bench, a laser driver electronics board, a custom-designed miniature spectrometer with an optical resolution of 8 cm-1 and a netbook to control the spectrometer as well as for data evaluation. We introduced for the first time the portable Raman sensor system on an Artic sea-trial during a three week cruise on board of the James Clark Ross research vessel in August 2011. Numerous Raman and SERS measurements followed by SERDS evaluations were taken around locations 78° N and 9° E. Different SERS substrates developed for SERS measurements in sea-water were tested for their capability to detect different substances (PAHs) in the water down to very small (nmol/l) concentrations. Stability tests of the substrates were carried out also for the applicability of our system e.g. on a mooring. Details of the in-situ Raman sensor were presented

  1. Soft X-ray spectroscopic investigations in experiments on Z-pinch stabilization

    International Nuclear Information System (INIS)

    Pikuz, S.A.; Skobelev, I.Yu.

    1996-01-01

    X-ray spectroscopic methods were used to investigate the spatial distribution of Z-pinch plasma parameters. Experiments were carried out on the GAEL pulse line generator in Ecole Polytechnique (France) with different types of load. Obtained results for the concentration of electrons and plasma temperature showed that higher plasma homogeneity was obtained in experiments with complex load. Spectrograms demonstrate the stabilization effect of the A1-jet. (orig.)

  2. Soft X-ray spectroscopic investigations in experiments on Z-pinch stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Pikuz, S.A. [Rossijskaya Akademiya Nauk, Moscow (Russian Federation). Fizicheskij Inst.; Shelkovenko, T.A. [Rossijskaya Akademiya Nauk, Moscow (Russian Federation). Fizicheskij Inst.; Romanova, V.M. [Rossijskaya Akademiya Nauk, Moscow (Russian Federation). Fizicheskij Inst.; Etlicher, B. [Ecole Polytechnique, Palaseau (France). Lab. de Phys. des Mililux Ionises; Attelan, S. [Ecole Polytechnique, Palaseau (France). Lab. de Phys. des Mililux Ionises; Chuvatin, A.S. [Ecole Polytechnique, Palaseau (France). Lab. de Phys. des Mililux Ionises; Faenov, A.Ya. [MISDC VNIIFTRI, Moscow (Russian Federation); Skobelev, I.Yu. [MISDC VNIIFTRI, Moscow (Russian Federation)

    1996-04-01

    X-ray spectroscopic methods were used to investigate the spatial distribution of Z-pinch plasma parameters. Experiments were carried out on the GAEL pulse line generator in Ecole Polytechnique (France) with different types of load. Obtained results for the concentration of electrons and plasma temperature showed that higher plasma homogeneity was obtained in experiments with complex load. Spectrograms demonstrate the stabilization effect of the A1-jet. (orig.).

  3. High pressure Raman scattering study on the phase stability of LuVO4

    International Nuclear Information System (INIS)

    Rao, Rekha; Garg, Alka B.; Sakuntala, T.; Achary, S.N.; Tyagi, A.K.

    2009-01-01

    High pressure Raman spectroscopic investigations have been carried out on rare earth orthovanadate LuVO 4 upto 26 GPa. Changes in the Raman spectrum around 8 GPa across the reported zircon to scheelite transition are investigated in detail and compared with those observed in other vanadates. Co-existence of the zircon and scheelite phases is observed over a pressure range of about 8-13 GPa. The zircon to scheelite transition is irreversible upon pressure release. Subtle changes are observed in the Raman spectrum above 16 GPa which could be related to scheelite ↔ fergusonite transition. Pressure dependencies of the Raman active modes in the zircon and the scheelite phases are reported. - Graphical abstract: Study of scheelite-fergusonite transition in RVO 4 by Raman spectroscopy is rare. Here we report Raman spectroscopic investigations of LuVO 4 at high pressure to obtain insight into nature of post-scheelite phases.

  4. Specific binding of a dihydropyrimidinone derivative with DNA: Spectroscopic, calorimetric and modeling investigations

    International Nuclear Information System (INIS)

    Wang Gongke; Yan Changling; Wang Dongchao; Li Dan; Lu Yan

    2012-01-01

    One of the dihydropyrimidinone derivative 5-(ethoxycarbonyl)-6-methyl-4-(4-methoxyphenyl) -3,4-dihydropyrimidin-2(1H)-one (EMMD) was synthesized, and its binding properties with calf-thymus DNA (ctDNA) were investigated using spectroscopic, viscometric, isothermal titration calorimetric (ITC) and molecular modeling techniques. Fluorescence spectra suggested that the fluorescence enhancement of the binding interaction of EMMD to ctDNA was a static process with ground state complex formation. The binding constant determined with spectroscopic titration and ITC was found to be in the same order of 10 4 M −1 . According to the results of the viscosity analysis, fluorescence competitive binding experiment, fluorescence quenching studies, absorption spectral and ITC investigations, it can be concluded that EMMD is intercalative binding to ctDNA. Furthermore, the results of molecular modeling confirmed those obtained from spectroscopic, viscosimetric and ITC investigations. Additionally, ITC studies also indicated that the binding interaction is predominantly enthalpy driven. - Highlights: ► Medically important dihydropyrimidinones derivative EMMD is synthesized. ► EMMD is intercalative binding into ctDNA helix. ► Hydrogen bonding may play an essential role in the binding of EMCD with ctDNA. ► This binding interaction is predominantly enthalpy driven.

  5. Raman and IR spectroscopic structural characterization of LiAlO2 powders prepared using a liquid mix technique

    International Nuclear Information System (INIS)

    Cornilsen, B.C.; Loyselle, P.L.; Saporta, J.D.

    1990-01-01

    γ-LiAlO 2 and β-LiAlO 2 have been characterized using Raman and infrared spectroscopy. Powders have been prepared using two different preparation techniques: a solution method known as the liquid mix technique (LMT) and the traditional ceramic method. The authors find that the LMT allows direct production of single phase γ-LiAlO 2 at 600 degrees C, below that found using other preparation methods. Furthermore, this solution technique appears to avoid formation of the β-LiAlO 2 intermediate phase. At lower temperatures, the LMT product is a disordered precursor of γ- LiAlO 2

  6. Remote Raman - laser induced breakdown spectroscopy (LIBS) geochemical investigation under Venus atmospheric conditions

    Energy Technology Data Exchange (ETDEWEB)

    Clegg, Sanuel M [Los Alamos National Laboratory; Barefield, James E [Los Alamos National Laboratory; Humphries, Seth D [Los Alamos National Laboratory; Wiens, Roger C [Los Alamos National Laboratory; Vaniman, D. T. [Los Alamos National Laboratory; Sharma, S. K. [UNIV OF HAWAII; Misra, A. K. [UNIV OF HAWAII; Dyar, M. D. [MT. HOLYOKE COLLEGE; Smrekar, S. E. [JET PROPULSION LAB.

    2010-12-13

    The extreme Venus surface temperatures ({approx}740 K) and atmospheric pressures ({approx}93 atm) create a challenging environment for surface missions. Scientific investigations capable of Venus geochemical observations must be completed within hours of landing before the lander will be overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing the geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. and Sharma et al. demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with Raman - LIBS and demonstrate quantitative analysis under Venus surface conditions. Raman and LIBS are highly complementary analytical techniques capable of detecting both the mineralogical and geochemical composition of Venus surface materials. These techniques have the potential to profoundly increase our knowledge of the Venus surface composition, which is currently limited to geochemical data from Soviet Venera and VEGA landers that collectively suggest a surface composition that is primarily tholeiitic basaltic with some potentially more evolved compositions and, in some locations, K-rich trachyandesite. These landers were not equipped to probe the surface mineralogy as can be accomplished with Raman spectroscopy. Based on the observed compositional differences and recognizing the imprecise nature of the existing data, 15 samples were chosen to constitute a Venus-analog suite for this study, including five basalts, two each of andesites, dacites, and sulfates, and single samples of a foidite, trachyandesite, rhyolite, and basaltic trachyandesite under Venus conditions. LIBS data reduction involved generating a partial least squares (PLS) model with a subset of the rock powder standards to

  7. Qualitative and quantitative changes in phospholipids and proteins investigated by spectroscopic techniques in animal depression model

    Science.gov (United States)

    Depciuch, J.; Sowa-Kucma, M.; Nowak, G.; Papp, M.; Gruca, P.; Misztak, P.; Parlinska-Wojtan, M.

    2017-04-01

    Depression becomes nowadays a high mortality civilization disease with one of the major causes being chronic stress. Raman, Fourier Transform Infra Red (FTIR) and Ultraviolet-Visible (UV-vis) spectroscopies were used to determine the changes in the quantity and structure of phospholipids and proteins in the blood serum of rats subjected to chronic mild stress, which is a common animal depression model. Moreover, the efficiency of the imipramine treatment was evaluated. It was found that chronic mild stress not only damages the structure of the phospholipids and proteins, but also decreases their level in the blood serum. A 5 weeks imipramine treatment did increase slightly the quantity of proteins, leaving the damaged phospholipids unchanged. Structural information from phospholipids and proteins was obtained by UV-vis spectroscopy combined with the second derivative of the FTIR spectra. Indeed, the structure of proteins in blood serum of stressed rats was normalized after imipramine therapy, while the impaired structure of phospholipids remained unaffected. These findings strongly suggest that the depression factor, which is chronic mild stress, may induce permanent (irreversible) damages into the phospholipid structure identified as shortened carbon chains. This study shows a possible new application of spectroscopic techniques in the diagnosis and therapy monitoring of depression.

  8. Energy profile, spectroscopic (FT-IR, FT-Raman and FT-NMR) and DFT studies of 4-bromoisophthalic acid

    Science.gov (United States)

    Arjunan, V.; Thirunarayanan, S.; Mohan, S.

    2018-04-01

    The stable conformer of 4-bromoisophthalic acid (BIPA) has been identified by potential energy profile analysis. All the structural parameters of 4-bromoisophthalic acid are determined by B3LYP method with 6-311++G**, 6-31G** and cc-pVTZ basis sets. The fundamental vibrations are analysed with the use of FT-IR (4000-400 cm-1) and FT-Raman (4000-100 cm-1) spectra. The harmonic vibrational frequencies are theoretically calculated and compared with experimental FTIR and FT-Raman frequencies. The 1H and 13C NMR spectra have been analysed and compared with theoretical 1H and 13C NMR chemical shifts calculated by gauge independent atomic orbital (GIAO) method. The electronic properties, such as HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energies are determined by B3LYP/cc-pVTZ method. The electron density distribution and site of chemical reactivity of BIPA molecule have been obtained by mapping electron density isosurface with molecular electrostatic potential (MEP). Stability of the molecules arising from hyperconjugative interactions, charge delocalizations have been analysed by using natural bond orbital (NBO) analysis. The thermodynamic properties and atomic natural charges of the compound are analysed and the reactive sites of the molecule are identified. The global and local reactivity descriptors are evaluated to analyse the chemical reactivity and site selectivity of molecule through Fukui functions.

  9. Advanced statistical analysis of Raman spectroscopic data for the identification of body fluid traces: semen and blood mixtures.

    Science.gov (United States)

    Sikirzhytski, Vitali; Sikirzhytskaya, Aliaksandra; Lednev, Igor K

    2012-10-10

    Conventional confirmatory biochemical tests used in the forensic analysis of body fluid traces found at a crime scene are destructive and not universal. Recently, we reported on the application of near-infrared (NIR) Raman microspectroscopy for non-destructive confirmatory identification of pure blood, saliva, semen, vaginal fluid and sweat. Here we expand the method to include dry mixtures of semen and blood. A classification algorithm was developed for differentiating pure body fluids and their mixtures. The classification methodology is based on an effective combination of Support Vector Machine (SVM) regression (data selection) and SVM Discriminant Analysis of preprocessed experimental Raman spectra collected using an automatic mapping of the sample. This extensive cross-validation of the obtained results demonstrated that the detection limit of the minor contributor is as low as a few percent. The developed methodology can be further expanded to any binary mixture of complex solutions, including but not limited to mixtures of other body fluids. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  10. Localized tip enhanced Raman spectroscopic study of impurity incorporated single GaN nanowire in the sub-diffraction limit

    International Nuclear Information System (INIS)

    Patsha, Avinash; Dhara, Sandip; Tyagi, A. K.

    2015-01-01

    The localized effect of impurities in single GaN nanowires in the sub-diffraction limit is reported using the study of lattice vibrational modes in the evanescent field of Au nanoparticle assisted tip enhanced Raman spectroscopy (TERS). GaN nanowires with the O impurity and the Mg dopants were grown by the chemical vapor deposition technique in the catalyst assisted vapor-liquid-solid process. Symmetry allowed Raman modes of wurtzite GaN are observed for undoped and doped nanowires. Unusually very strong intensity of the non-zone center zone boundary mode is observed for the TERS studies of both the undoped and the Mg doped GaN single nanowires. Surface optical mode of A 1 symmetry is also observed for both the undoped and the Mg doped GaN samples. A strong coupling of longitudinal optical (LO) phonons with free electrons, however, is reported only in the O rich single nanowires with the asymmetric A 1 (LO) mode. Study of the local vibration mode shows the presence of Mg as dopant in the single GaN nanowires

  11. Localized tip enhanced Raman spectroscopic study of impurity incorporated single GaN nanowire in the sub-diffraction limit

    Energy Technology Data Exchange (ETDEWEB)

    Patsha, Avinash, E-mail: avinash.phy@gmail.com, E-mail: dhara@igcar.gov.in; Dhara, Sandip; Tyagi, A. K. [Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2015-09-21

    The localized effect of impurities in single GaN nanowires in the sub-diffraction limit is reported using the study of lattice vibrational modes in the evanescent field of Au nanoparticle assisted tip enhanced Raman spectroscopy (TERS). GaN nanowires with the O impurity and the Mg dopants were grown by the chemical vapor deposition technique in the catalyst assisted vapor-liquid-solid process. Symmetry allowed Raman modes of wurtzite GaN are observed for undoped and doped nanowires. Unusually very strong intensity of the non-zone center zone boundary mode is observed for the TERS studies of both the undoped and the Mg doped GaN single nanowires. Surface optical mode of A{sub 1} symmetry is also observed for both the undoped and the Mg doped GaN samples. A strong coupling of longitudinal optical (LO) phonons with free electrons, however, is reported only in the O rich single nanowires with the asymmetric A{sub 1}(LO) mode. Study of the local vibration mode shows the presence of Mg as dopant in the single GaN nanowires.

  12. Raman Spectroscopic Analysis Reveals Abnormal Fatty Acid Composition in Tumor Micro- and Macroenvironments in Human Breast and Rat Mammary Cancer.

    Science.gov (United States)

    You, Sixian; Tu, Haohua; Zhao, Youbo; Liu, Yuan; Chaney, Eric J; Marjanovic, Marina; Boppart, Stephen A

    2016-09-06

    Fatty acids play essential roles in the growth and metastasis of cancer cells. To facilitate their avid growth and proliferation, cancer cells not only alter the fatty acid synthesis and metabolism intracellularly and extracellularly, but also in the macroenvironment via direct or indirect pathways. We report here, using Raman micro-spectroscopy, that an increase in the production of polyunsaturated fatty acids (PUFAs) was identified in both cancerous and normal appearing breast tissue obtained from breast cancer patients and tumor-bearing rats. By minimizing confounding effects from mixed chemicals and optimizing the signal-to-noise ratio of Raman spectra, we observed a large-scale transition from monounsaturated fatty acids to PUFAs in the tumor while only a small subset of fatty acids transitioned to PUFAs in the tumor micro- and macroenvironment. These data have important implications for further clarifying the macroenvironmental effect of cancer progression and provide new potential approaches for characterizing the tumor micro- and macroenvironment of breast cancer in both pre-clinical animal studies and clinical applications.

  13. Raman and optical spectroscopic studies of small-to-large polaron crossover in the perovskite manganese oxides

    International Nuclear Information System (INIS)

    Yoon, S.; Liu, H.L.; Schollerer, G.; Cooper, S.L.; Han, P.D.; Payne, D.A.; Cheong, S.; Fisk, Z.

    1998-01-01

    We present an optical reflectance and Raman-scattering study of the A 1-x A ' x MnO 3 system as a function of temperature and doping (0.2≤x≤0.5). The metal-semiconductor transition in the A 1-x A ' x MnO 3 system is characterized by a change from a diffusive electronic Raman-scattering response in the high-temperature paramagnetic phase, to a flat continuum scattering response in the low-temperature ferromagnetic phase. We interpret this change in the scattering response as a crossover from a small-polaron-dominated regime at high temperatures to a large-polaron-dominated low-temperature regime. Interestingly, we observe evidence for the coexistence of large and small polarons in the low-temperature ferromagnetic phase. We contrast these results with those obtained for EuB 6 , which is a low-T c magnetic semiconductor with similar properties to the manganites, but with a substantially reduced carrier density and polaron energy. copyright 1998 The American Physical Society

  14. Investigation of dodecane in three-dimensional porous graphene sponge by Raman mapping

    International Nuclear Information System (INIS)

    Guo, Xitao; Zafar, Amina; Shi, Zhixiang; Ni, Zhenhua; Bi, Hengchang; Sun, Litao; Liang, Zheng

    2016-01-01

    Three-dimensional (3D) carbon nano-materials, e.g. a graphene sponge (GS) are promising candidates for the removal of pollutants and the separation of oil and water. A systematic study on how oils or organic solvents disperse in the porous structures of 3D carbon nano-materials, and the factors affecting their sorption process, would be beneficial for designing a superior sorbent with desirable porous structures. Here, confocal Raman spectroscopic imaging was utilized to explore the absorption and desorption processes of dodecane (a constituent in petroleum products) in 3D porous GS with different pore size. It was found that dodecane predominately locates within the interior pores composed of reduced graphene oxide (rGO) sheets, which provide storage spaces for the absorbed molecules. The larger pore GS has a higher absorption capacity and faster desorption rate compared to the smaller one, which is due to the higher pore volume and weaker interaction with the absorbed molecules. A possible mechanism was also proposed to explain the role of porous macrostructures on the absorption and desorption properties of GSs. (paper)

  15. Ion implantation effects in single crystal Si investigated by Raman spectroscopy

    International Nuclear Information System (INIS)

    Harriman, T.A.; Lucca, D.A.; Lee, J.-K.; Klopfstein, M.J.; Herrmann, K.; Nastasi, M.

    2009-01-01

    A study of the effects of Ar ion implantation on the structural transformation of single crystal Si investigated by confocal Raman spectroscopy is presented. Implantation was performed at 77 K using 150 keV Ar ++ with fluences ranging from 2 x 10 13 to 1 x 10 15 ions/cm 2 . The Raman spectra showed a progression from crystalline to highly disordered structure with increasing fluence. The 520 cm -1 c-Si peak was seen to decrease in intensity, broaden and exhibit spectral shifts indicating an increase in lattice disorder and changes in the residual stress state. In addition, an amorphous Si band first appeared as a shoulder on the 520 cm -1 peak and then shifted to lower wavenumbers as a single broadband peak with a spectral center of 465 cm -1 . Additionally, the emergence of the a-Si TA phonon band and the decrease of the c-Si 2TA and 2TO phonon bands also indicated the same structural transition from crystalline to highly disordered. The Raman results were compared to those obtained by channeling RBS.

  16. Investigation of the interaction between magnetic nanoparticles surface-coated with carboxymethyldextran and blood cells using Raman spectroscopy

    International Nuclear Information System (INIS)

    Santana, J.F.B.; Soler, M.A.G.; Silva, S.W. da; Guedes, M.H.; Lacava, Z.G.M.; Azevedo, R.B.; Morais, P.C.

    2005-01-01

    This study reports on in vitro biological tests performed with a biocompatible magnetic fluid based on carboxymethyldextran-coated magnetite nanoparticles (CMDM). Micro Raman spectroscopy was used to investigate the effect of dispersing (CMDM) nanoparticles in mice blood. We focused our investigation in the use of the Raman spectroscopy for monitoring the hemoglobin structural changes, which may be associated with the oxygen-binding process

  17. Intercalation of iron hexacyano complexes in Zn,Al hydrotalcite. Part 2. A mid-infrared and Raman spectroscopic study

    International Nuclear Information System (INIS)

    Kloprogge, J.T.; Weier, Matt; Crespo, Inmaculada; Ulibarri, M.A.; Barriga, Cristobalina; Rives, V.; Martens, W.N.; Frost, R.L.

    2004-01-01

    Combined mid-IR and Raman spectroscopies indicate that intercalation of hexacyanoferrate (II) and (III) in the interlayer space of a Zn,Al hydrotalcite dried at 60 deg. C leads to layered solids where the intercalated species correspond to both hexacyanoferrate(II) and (III). This is an indication that depending on the oxidation state of the initial hexacyanoferrate, partial oxidation and reduction takes place upon intercalation. The symmetry of the intercalated hexacyanoferrate decreases from O h existing in the free anions to D 3d . The observation of a broad band around 2080 cm -1 is indicative of the removal of cyanide from the intercalation complex to the outside surface of the crystals. Its position in the intercalation complex is probably filled by a hydroxyl group

  18. Raman, photoluminescence and EPR spectroscopic characterization of europium(III) oxide–lead dioxide–tellurite glassy network

    Energy Technology Data Exchange (ETDEWEB)

    Dehelean, A. [National Research and Development Institute for Isotopic and Molecular Technologies, Cluj-Napoca (Romania); Rada, S. [Technical University of Cluj-Napoca (Romania); Popa, A.; Suciu, R.C. [National Research and Development Institute for Isotopic and Molecular Technologies, Cluj-Napoca (Romania); Culea, E., E-mail: eugen.culea@phys.utcluj.ro [Technical University of Cluj-Napoca (Romania)

    2016-09-15

    Raman, photoluminescence and EPR spectroscopies were used to characterize some xEu{sub 2}O{sub 3}·(100−x)[4TeO{sub 2}·PbO{sub 2}] glasses with x=0–50 mol% obtained by melt quenching technique. Raman spectra of these glasses were interpreted in terms of vibration modes of deformed Te–O–Te linkages due to the intercalation of [PbO{sub n}] and [EuO{sub n}] entities produced by addition of Eu{sub 2}O{sub 3} to the host lead–tellurite glass. Photoluminescence spectra of xEu{sub 2}O{sub 3}·(100−x)[4TeO{sub 2}·PbO{sub 2}] glasses reveal the presence of Pb{sup 2+}, Eu{sup 2+} and Eu{sup 3+} ions. EPR data confirm the presence of Eu{sup 2+} ions in the europium–lead–tellurite glassy network and offer information about the compositional evolution of the Eu{sup 2+} ions local environment and Eu{sup 3+}↔Eu{sup 2+} redox process. PL and EPR data show that the decrease of the Eu{sup 2+} ions luminescence intensity for the x≥40 mol% Eu{sub 2}O{sub 3} region is not due to the clusterization of europium ions but is due the decrease of the amount of Eu{sup 2+} ions as result of changes in the Eu{sup 3+}→Eu{sup 2+} redox equilibrium.

  19. Raman spectroscopic analysis of human skin tissue sections ex-vivo: evaluation of the effects of tissue processing and dewaxing

    Science.gov (United States)

    Ali, Syed M.; Bonnier, Franck; Tfayli, Ali; Lambkin, Helen; Flynn, Kathleen; McDonagh, Vincent; Healy, Claragh; Clive Lee, T.; Lyng, Fiona M.; Byrne, Hugh J.

    2013-06-01

    Raman spectroscopy coupled with K-means clustering analysis (KMCA) is employed to elucidate the biochemical structure of human skin tissue sections and the effects of tissue processing. Both hand and thigh sections of human cadavers were analyzed in their unprocessed and formalin-fixed, paraffin-processed (FFPP), and subsequently dewaxed forms. In unprocessed sections, KMCA reveals clear differentiation of the stratum corneum (SC), intermediate underlying epithelium, and dermal layers for sections from both anatomical sites. The SC is seen to be relatively rich in lipidic content; the spectrum of the subjacent layers is strongly influenced by the presence of melanin, while that of the dermis is dominated by the characteristics of collagen. For a given anatomical site, little difference in layer structure and biochemistry is observed between samples from different cadavers. However, the hand and thigh sections are consistently differentiated for all cadavers, largely based on lipidic profiles. In dewaxed FFPP samples, while the SC, intermediate, and dermal layers are clearly differentiated by KMCA of Raman maps of tissue sections, the lipidic contributions to the spectra are significantly reduced, with the result that respective skin layers from different anatomical sites become indistinguishable. While efficient at removing the fixing wax, the tissue processing also efficiently removes the structurally similar lipidic components of the skin layers. In studies of dermatological processes in which lipids play an important role, such as wound healing, dewaxed samples are therefore not appropriate. Removal of the lipids does however accentuate the spectral features of the cellular and protein components, which may be more appropriate for retrospective analysis of disease progression and biochemical analysis using tissue banks.

  20. In-situ Raman spectroscopic study of aluminate speciation in H2O-KOH solutions at high pressures and temperatures

    Science.gov (United States)

    Mookherjee, M.; Keppler, H.; Manning, C. E.

    2009-12-01

    The solubility of corundum in H2O is low even at high pressure and temperatures. Therefore, it is commonly assumed that alumina remains essentially immobile during fluid-rock interaction. However, field and experimental evidence suggests that alumina solubility is strongly enhanced in the presence of silica as well as in alkaline solutions. In order to understand what controls the alumina solubility and how it is enhanced as a function of fluid composition, we conducted Raman-spectroscopic study of Al speciation in aqueous fluids at high pressure and temperature. Experiments were carried out in an externally heated hydrothermal diamond-anvil cell equipped with low-fluorescence diamonds and iridium gaskets. Raman spectra were collected with a Horiba Jobin-Yvon Labram HR spectrometer using the 514 nm line of an argon laser for excitation. In a first series of experiments, the speciation of alumina was studied in a 1 M KOH solution in equilibrium with corundum up to 700 oC and ~1 GPa. The Raman spectra show a prominent band at 618 cm-1 interpreted to arise from Al-O stretching vibrations associated with the tetrahedral [Al(OH)4]1- species. At higher pressure and temperature, an additional vibrational mode appears in the spectra at 374 cm-1 (full width at half maximum ~ 20 cm-1). This feature is tentatively attributed to [(OH)3Al-O-Al(OH)3]2- (Moolenaar et al. 1970, Jour. Phys. Chem., 74, 3629-3636). No evidence for KAl(OH)4 was observed, consistent with piston cylinder experiments at 700 oC and 1 GPa (Wohlers & Manning, 2009, Chem. Geol., 262, 310). Upon cooling from high-pressure and high temperature, slow kinetics of corundum regrowth lead to oversaturation in the solutions, as evidenced by sharp peaks at 930 and 1066 cm-1 observed upon cooling. These features are probably due to colloidal aluminum hydroxide. The results provide the first evidence for aluminate polymerization at high pressure and temperature, and offer insights into the causes for enhancement of

  1. Investigation of various factors influencing Raman spectra interpretation with the use of likelihood ratio approach.

    Science.gov (United States)

    Michalska, Aleksandra; Martyna, Agnieszka; Zadora, Grzegorz

    2018-01-01

    The main aim of this study was to verify whether selected analytical parameters may affect solving the comparison problem of Raman spectra with the use of the likelihood ratio (LR) approach. Firstly the LR methodologies developed for Raman spectra of blue automotive paints obtained with the use of 785nm laser source (results published by the authors previously) were implemented for good quality spectra recorded for these paints with the use of 514.5nm laser source. For LR models construction two types of variables were used i.e. areas under selected pigments bands and coefficients derived from discrete wavelet transform procedure (DWT). Few experiments were designed for 785nm and 514.5nm Raman spectra databases after constructing well performing LR models (low rates of false positive and false negative answers and acceptable results of empirical cross entropy approach). In order to verify whether objective magnification described by its numerical aperture affects spectra interpretation, three objective magnifications -20×(N.A.=0.4.), 50×(N.A.=0.75) and 100×(N.A.=0.85) within each of the applied laser sources (514.5nm and 785nm) were tested for a group of blue solid and metallic automotive paints having the same sets of pigments depending on the applied laser source. The findings obtained by two types of LR models indicate the importance of this parameter for solving the comparison problem of both solid and metallic automotive paints regardless of the laser source used for measuring Raman signal. Hence, the same objective magnification, preferably 50× (established based on the analysis of within- and between-samples variability and F-factor value), should be used when focusing the laser on samples during Raman measurements. Then the influence of parameters (laser power and time of irradiation) of one of the recommended fluorescence suppression techniques, namely photobleaching, was under investigation. Analysis performed on a group of solid automotive paint

  2. Hydrogel-Embedded Model Photocatalytic System Investigated by Raman and IR Spectroscopy Assisted by Density Functional Theory Calculations and Two-Dimensional Correlation Analysis.

    Science.gov (United States)

    Geitner, Robert; Götz, Stefan; Stach, Robert; Siegmann, Michael; Krebs, Patrick; Zechel, Stefan; Schreyer, Kristin; Winter, Andreas; Hager, Martin D; Schubert, Ulrich S; Gräfe, Stefanie; Dietzek, Benjamin; Mizaikoff, Boris; Schmitt, Michael; Popp, Jürgen

    2018-03-15

    The presented study reports the synthesis and the vibrational spectroscopic characterization of different matrix-embedded model photocatalysts. The goal of the study is to investigate the interaction of a polymer matrix with photosensitizing dyes and metal complexes for potential future photocatalytic applications. The synthesis focuses on a new rhodamine B derivate and a Pt(II) terpyridine complex, which both contain a polymerizable methacrylate moiety and an acid labile acylhydrazone group. The methacrylate moieties are afterward utilized to synthesize functional model hydrogels mainly consisting of poly(ethylene glycol) methacrylate units. The pH-dependent and temperature-dependent behavior of the hydrogels is investigated by means of Raman and IR spectroscopy assisted by density functional theory calculations and two-dimensional correlation spectroscopy. The spectroscopic results reveal that the Pt(II) terpyridine complex can be released from the polymer matrix by cleaving the C═N bond in an acid environment. The same behavior could not be observed in the case of the rhodamine B dye although it features a comparable C═N bond. The temperature-dependent study shows that the water evaporation has a significant influence neither on the molecular structure of the hydrogel nor on the model photocatalytic moieties.

  3. Raman spectroscopy used for structural investigations of anodically formed ZrO2

    International Nuclear Information System (INIS)

    Koneska, Zagorka; Arsova, Irena

    2003-01-01

    The structure of the oxide formed on Zr(99% + Hf) with anodic oxidation at different potentials in 1 mol/dm 3 H 3 PO 4 and 2 mol/dm 3 KOH solutions were investigated using Raman spectroscopy. Normally the anodic oxides of Zr form only crystals. Under certain circumstances, amorphous anodic ZrO 2 can be observed. Amorphous phase is observed for the anodically formed zirconium oxides in H 3 PO 4 . The oxide formed in KOH at potential of 80 V, where sparks appears on the Zr electrode showed crystalline structure. (Original)

  4. Raman spectroscopic analysis of the increase of the carotenoid antioxidant concentration in human skin after a 1-week diet with ecological eggs

    Science.gov (United States)

    Hesterberg, Karoline; Lademann, Jürgen; Patzelt, Alexa; Sterry, Wolfram; Darvin, Maxim E.

    2009-03-01

    Skin aging is mainly caused by the destructive action of free radicals, produced by the UV light of the sun. The human skin has developed a protection system against these highly reactive molecules in the form of the antioxidative potential. Carotenoids are one of the main components of the antioxidants of the human skin. From former studies, it is known that skin aging is reduced in individuals with high levels of carotenoids. Because most of the antioxidants cannot be produced by the human organism, they must be up taken by nutrition. Using noninvasive Raman spectroscopic measurements it is demonstrated that not only fruits and vegetables but also eggs contain high concentrations of antioxidants including carotenoids, which are even doubled in the case of ecological eggs. After a 1-week diet with ecological eggs performed by six volunteers, it is found that the concentration of the carotenoids in the skin of the volunteers increased by approx. 20%. Our study does not intend to recommend exorbitant egg consumption, as eggs also contain harmful cholesterol. But in the case of egg consumption, ecological eggs from hens kept on pasture should be preferred to also receive a benefit for the skin.

  5. Spectroscopic ellipsometry investigations of optical anisotropy in obliquely deposited hafnia thin films

    Energy Technology Data Exchange (ETDEWEB)

    Tokas, R. B., E-mail: tokasstar@gmail.com; Jena, Shuvendu; Thakur, S.; Sahoo, N. K. [Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai-85 (India); Haque, S. Maidul; Rao, K. Divakar [Photonics & Nanotechnology Section, Atomic & Molecular Physics Division, Bhabha Atomic Research Centre facility, Visakhapatnam-530012 (India)

    2016-05-23

    In present work, HfO{sub 2} thin films have been deposited at various oblique incidences on Si substrates by electron beam evaporation. These refractory oxide films exhibited anisotropy in refractive index predictably due to special columnar microstructure. Spectroscopic ellipsometry being a powerful tool for optical characterization has been employed to investigate optical anisotropy. It was observed that the film deposited at glancing angle (80°) exhibits the highest optical anisotropy. Further, anisotropy was noticed to decrease with lower values of deposition angles while effective refractive index depicts opposite trend. Variation in refractive index and anisotropy has been explained in light of atomic shadowing during growth of thin films at oblique angles.

  6. Influence of phototherapies on the outcome of complete tibial fractures grafted or not with MTA: Raman spectroscopic study on rabbits

    Science.gov (United States)

    Pinheiro, Antônio L. B.; Soares, Luiz G. P.; da Silva, Aline C. P.; Santos, Nicole R. S.; da Silva, Anna Paula L. T.; Neves, Bruno Luiz R. C.; Soares, Amanda P.; Silveira, Landulfo

    2018-02-01

    The aim of the present study was to assess, by means of Raman spectroscopy, the repair of complete surgical tibial fractures fixed with wire osteosynthesis or miniplates treated or not with infrared laser (λ780 nm) or infrared LED (λ850 +/- 10 nm) lights, 142.8 J/cm2 per treatment, associated or not to the use of mineral trioxide aggregate (MTA) cement. Surgical fractures were created on 36 rabbits and fixed with WO or miniplates and some groups were grafted with MTA. Irradiated groups received lights at every other day for 15 days and sacrifice occurred after 30 days. The results showed that only irradiation with either laser or LED influenced the peaks of phosphate ( 960 cm-1) and carbonated ( 1,070 cm-1) hydroxyapatite. Collagen peak (1,450 cm-1) was influenced by both the use of MTA and irradiation with either laser or LED. It is concluded that the use of either laser or LED phototherapy associated to MTA cement was efficacious on improving the repair of complete tibial fractures treated with wire osteosynthesis or miniplates.

  7. Chromate adsorption on selected soil minerals: Surface complexation modeling coupled with spectroscopic investigation

    Energy Technology Data Exchange (ETDEWEB)

    Veselská, Veronika, E-mail: veselskav@fzp.czu.cz [Department of Environmental Geosciences, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcka 129, CZ-16521, Prague (Czech Republic); Fajgar, Radek [Department of Analytical and Material Chemistry, Institute of Chemical Process Fundamentals of the CAS, v.v.i., Rozvojová 135/1, CZ-16502, Prague (Czech Republic); Číhalová, Sylva [Department of Environmental Geosciences, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcka 129, CZ-16521, Prague (Czech Republic); Bolanz, Ralph M. [Institute of Geosciences, Friedrich-Schiller-University Jena, Carl-Zeiss-Promenade 10, DE-07745, Jena (Germany); Göttlicher, Jörg; Steininger, Ralph [ANKA Synchrotron Radiation Facility, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, DE-76344, Eggenstein-Leopoldshafen (Germany); Siddique, Jamal A.; Komárek, Michael [Department of Environmental Geosciences, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcka 129, CZ-16521, Prague (Czech Republic)

    2016-11-15

    Highlights: • Study of Cr(VI) adsorption on soil minerals over a large range of conditions. • Combined surface complexation modeling and spectroscopic techniques. • Diffuse-layer and triple-layer models used to obtain fits to experimental data. • Speciation of Cr(VI) and Cr(III) was assessed. - Abstract: This study investigates the mechanisms of Cr(VI) adsorption on natural clay (illite and kaolinite) and synthetic (birnessite and ferrihydrite) minerals, including its speciation changes, and combining quantitative thermodynamically based mechanistic surface complexation models (SCMs) with spectroscopic measurements. Series of adsorption experiments have been performed at different pH values (3–10), ionic strengths (0.001–0.1 M KNO{sub 3}), sorbate concentrations (10{sup −4}, 10{sup −5}, and 10{sup −6} M Cr(VI)), and sorbate/sorbent ratios (50–500). Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy were used to determine the surface complexes, including surface reactions. Adsorption of Cr(VI) is strongly ionic strength dependent. For ferrihydrite at pH <7, a simple diffuse-layer model provides a reasonable prediction of adsorption. For birnessite, bidentate inner-sphere complexes of chromate and dichromate resulted in a better diffuse-layer model fit. For kaolinite, outer-sphere complexation prevails mainly at lower Cr(VI) loadings. Dissolution of solid phases needs to be considered for better SCMs fits. The coupled SCM and spectroscopic approach is thus useful for investigating individual minerals responsible for Cr(VI) retention in soils, and improving the handling and remediation processes.

  8. Structural, Spectroscopic (FT-IR, Raman and NMR, Non-linear Optical (NLO, HOMO-LUMO and Theoretical (DFT/CAM-B3LYP Analyses of N-Benzyloxycarbonyloxy-5-Norbornene-2,3-Dicarboximide Molecule

    Directory of Open Access Journals (Sweden)

    Nuri ÖZTÜRK

    2018-02-01

    Full Text Available The experimental spectroscopic investigation of N-benzyloxycarbonyloxy-5-norbornene-2,3-dicarboximide (C17H15NO5 molecule has been done using 1H and 13C NMR chemical shifts, FT-IR and Raman spectroscopies. Conformational forms have been determined depending on orientation of N-benzyloxycarbonyloxy and 5-norbornene-2,3-dicarboximide (NDI groups of the title compound. The structural geometric optimizations, vibrational wavenumbers, NMR chemical shifts (in vacuum and chloroform and HOMO-LUMO analyses for all conformers of the title molecule have been done with DFT/CAM-B3LYP method at the 6-311++G(d,p basis set. Additionally, based on the calculated HOMO and LUMO energy values, some molecular properties such as ionization potential (I, electron affinity (A, electronegativity (χ, chemical hardness (h, chemical softness (z, chemical potential (μ and electrophilicity index (w parameters are determined for all conformers. The non-linear optical (NLO properties have been studied for the title molecule. We can say that the experimental spectral data are in accordance with calculated values.

  9. Differential Control of Heme Reactivity in Alpha and Beta Subunits of Hemoglobin: A Combined Raman Spectroscopic and Computational Study

    Science.gov (United States)

    2015-01-01

    The use of hybrid hemoglobin (Hb), with mesoheme substituted for protoheme, allows separate monitoring of the α or β hemes along the allosteric pathway. Using resonance Raman (rR) spectroscopy in silica gel, which greatly slows protein motions, we have observed that the Fe–histidine stretching frequency, νFeHis, which is a monitor of heme reactivity, evolves between frequencies characteristic of the R and T states, for both α or β chains, prior to the quaternary R–T and T–R shifts. Computation of νFeHis, using QM/MM and the conformational search program PELE, produced remarkable agreement with experiment. Analysis of the PELE structures showed that the νFeHis shifts resulted from heme distortion and, in the α chain, Fe–His bond tilting. These results support the tertiary two-state model of ligand binding (Henry et al., Biophys. Chem.2002, 98, 149). Experimentally, the νFeHis evolution is faster for β than for α chains, and pump–probe rR spectroscopy in solution reveals an inflection in the νFeHis time course at 3 μs for β but not for α hemes, an interval previously shown to be the first step in the R–T transition. In the α chain νFeHis dropped sharply at 20 μs, the final step in the R–T transition. The time courses are fully consistent with recent computational mapping of the R–T transition via conjugate peak refinement by Karplus and co-workers (Fischer et al., Proc. Natl. Acad. Sci. U. S. A.2011, 108, 5608). The effector molecule IHP was found to lower νFeHis selectively for α chains within the R state, and a binding site in the α1α2 cleft is suggested. PMID:24991732

  10. FT-Raman spectroscopic study of skin wound healing in diabetic rats treated with Cenostigma macrophyllum Tul

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, Nayana Pinheiro Machado de Freitas; Martins, Marcelino, E-mail: nayanamachado@oi.com.br [Faculdade Diferencial Integral (FACID), Teresina, PI (Brazil); Costa, Charlytton Luis Sena da; Maia Filho, Antonio Luis [Universidade Estadual do Piaui (UESPI), Teresina, PI (Brazil); Raniero, Leandro; Martin, Airton Abrahao; Arisawa, Emilia Angela Loschiavo [Universidade do Vale do Paraiba (UNIVAP), Sao Jose dos Campos, SP (Brazil). Instituto de Pesquisa e Desenvolvimento

    2014-07-01

    Introduction: patients with diabetes mellitus exhibit a delay in the lesion repair process. The active components of Cenostigma macrophyllum may represent a viable alternative to facilitate the recovery of these lesions. The aim of this study was to evaluate the effects of emulsion oil-water Cenostigma macrophyllum in the repair process of lesions in rats with induced diabetes. Methods: 63 male rats (Wistar, 200-250 g body weight, 30-40 days old) were distributed into the following groups: control (C), diabetic (D) and diabetic treated with Cenostigma macrophyllum (P), subdivided based on the experimental times, days 7, 14 and 28, with 21 animals per main group. Diabetes mellitus (DM) was induced by administration of streptozotocin (50 mg/kg via penile vein and 12-h fasting) and confirmed at day 21 (glycemic index > 240 mg/dL). In the animals of group P, 0.5 ml of the oil-water emulsion obtained from the plant seed was used. The samples were removed and hemisectioned, and one portion was used for the quantitative histological analysis of collagen using Masson's trichrome staining, while another portion was analyzed by FT-Raman spectroscopy. Results: A higher percentage area of the volume of collagen fibers was observed for the experimental time Day 14 in group P compared with group D (p < 0.001). Regarding the ratio of areas of the amides I (1700-1600 cm{sup -1}) and III (1245-1345 cm{sup -1}), the groups D and P show the opposite behavior. Conclusion: Cenostigma macrophyllum accelerated the repair process in skin of diabetic ratsfor14 days. (author)

  11. FT-Raman spectroscopic analysis of Nd:YAG and Er,Cr:YSGG laser irradiated enamel for preventive purposes

    Science.gov (United States)

    Ana, P. A.; Kauffmann, C. M. F.; Bachmann, L.; Soares, L. E. S.; Martin, A. A.; Gomes, A. S. L.; Zezell, D. M.

    2014-03-01

    This study evaluated the effect of combining laser irradiation with fluoride on an enamel microstructure and demineralization by FT-Raman spectroscopy (FTRS). Eighty human enamel slabs were divided into eight groups: (G1) untreated; (G2) acidulated phosphate fluoride application (APF—1.23% F- for 4 min) (G3) Nd:YAG irradiation (84.9 J cm-2, 60 mJ/pulse) (G4) Nd:YAG + APF; (G5) APF + Nd:YAG; (G6) Er,Cr:YSGG irradiation (2.8 J cm-2, 12.5 mJ/pulse) (G7) Er,Cr:YSGG + APF; and (G8) APF + Er,Cr:YSGG. After treatment, the samples were submitted to a ten-day pH-cycling model. Chemical changes were determined on the slabs before and after treatment, and also after pH-cycling, by FTRS in the range 400-4000 cm-1. The inorganic bands at 440, 590, 870, 960, 1100 cm-1, and the organic bands at 1270, 1450, 1670, 2945 cm-1 were considered. Demineralization promoted reduction in organic contents; Nd:YAG laser irradiation promoted loss of carbonate and organic content, while Er,Cr:YSGG did not produce significant changes in the relative band intensities of organic and inorganic contents of the enamel. In lased samples, no effects caused by pH-cycling on enamel were observed. In conclusion, laser treatment and its association with fluoride can somehow interfere with the demineralization dynamics, reducing its effects over the enamel.

  12. FT-Raman spectroscopic analysis of Nd:YAG and Er,Cr:YSGG laser irradiated enamel for preventive purposes

    International Nuclear Information System (INIS)

    Ana, P A; Kauffmann, C M F; Gomes, A S L; Bachmann, L; Soares, L E S; Martin, A A; Zezell, D M

    2014-01-01

    This study evaluated the effect of combining laser irradiation with fluoride on an enamel microstructure and demineralization by FT-Raman spectroscopy (FTRS). Eighty human enamel slabs were divided into eight groups: (G1) untreated; (G2) acidulated phosphate fluoride application (APF—1.23% F − for 4 min); (G3) Nd:YAG irradiation (84.9 J cm −2 , 60 mJ/pulse); (G4) Nd:YAG + APF; (G5) APF + Nd:YAG; (G6) Er,Cr:YSGG irradiation (2.8 J cm −2 , 12.5 mJ/pulse); (G7) Er,Cr:YSGG + APF; and (G8) APF + Er,Cr:YSGG. After treatment, the samples were submitted to a ten-day pH-cycling model. Chemical changes were determined on the slabs before and after treatment, and also after pH-cycling, by FTRS in the range 400−4000 cm −1 . The inorganic bands at 440, 590, 870, 960, 1100 cm −1 , and the organic bands at 1270, 1450, 1670, 2945 cm −1 were considered. Demineralization promoted reduction in organic contents; Nd:YAG laser irradiation promoted loss of carbonate and organic content, while Er,Cr:YSGG did not produce significant changes in the relative band intensities of organic and inorganic contents of the enamel. In lased samples, no effects caused by pH-cycling on enamel were observed. In conclusion, laser treatment and its association with fluoride can somehow interfere with the demineralization dynamics, reducing its effects over the enamel. (paper)

  13. Nuclear resonance vibrational spectroscopic studies of iron-containing biomolecules

    International Nuclear Information System (INIS)

    Ohta, Takehiro; Seto, Makoto

    2014-01-01

    In this review, we report recent nuclear resonance vibrational spectroscopic (NRVS) studies of iron-containing biomolecules and their model complexes. The NRVS is synchrotron-based element-specific vibrational spectroscopic methods. Unlike Raman and infrared spectroscopy, the NRVS can investigate all iron motions without selection rules, which provide atomic level insights into the structure/reactivity correlation of biologically relevant iron complexes. (author)

  14. QM/MM methodology, docking and spectroscopic (FT-IR/FT-Raman, NMR, UV) and Fukui function analysis on adrenergic agonist

    Science.gov (United States)

    Uma Maheswari, J.; Muthu, S.; Sundius, Tom

    2015-02-01

    The Fourier transform infrared, FT-Raman, UV and NMR spectra of Ternelin have been recorded and analyzed. Harmonic vibrational frequencies have been investigated with the help of HF with 6-31G (d,p) and B3LYP with 6-31G (d,p) and LANL2DZ basis sets. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by GIAO method. The polarizability (α) and the first hyperpolarizability (β) values of the investigated molecule have been computed using DFT quantum mechanical calculations. Stability of the molecule arising from hyper conjugative interactions, and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The electron density-based local reactivity descriptors such as Fukui functions were calculated to explain the chemical selectivity or reactivity site in Ternelin. Finally the calculated results were compared to simulated infrared and Raman spectra of the title compound which show good agreement with observed spectra. Molecular docking studies have been carried out in the active site of Ternelin and reactivity with ONIOM was also investigated.

  15. Formation of hydrothermal tin deposits: Raman spectroscopic evidence for an important role of aqueous Sn(IV) species

    Science.gov (United States)

    Schmidt, Christian

    2018-01-01

    The speciation of tin and the solubility of cassiterite in H2O + HCl were determined at temperatures to 600 °C using in situ Raman spectroscopy. In addition, information on the fluid-melt partition of Sn was obtained at 700 °C and indicated a preference of the fluid only at HCl concentrations that are much higher than in fluids exsolved from natural felsic melts. Dissolution of cassiterite generally resulted in formation of Sn(IV) species unless reduced conditions were generated by hydrogen permeation or carbohydrates in the starting material. The prevalent aqueous Sn(IV) species was [SnCl4(H2O)2]0, with additional [SnCl3(H2O)3]+ and [SnCl5(H2O)]-. The only detectable Sn(II) species was very likely [Sn(II)Cl3]-. Cassiterite solubility increased with HCl concentration and was generally high in H2O+HCl fluids, with no strong dependencies on temperature, pressure, or the oxidation state of tin in the fluid. The Sn(IV) concentrations at 500 and 600 °C determined from the integrated ν1[Sn(IV)sbnd Cl] band intensity are in good agreement with literature data on the cassiterite solubility in H2O + HCl at oxygen fugacities along the hematite-magnetite buffer. The combined results from previous experimental studies and this study demonstrate that HCl molality is a crucial parameter for hydrothermal mobilization and transport of tin and for cassiterite precipitation, and that pH, pressure and temperature are less important. Current models on hydrothermal tin deposit formation need to be augmented to include Sn(IV)sbnd Cl complexes as significant tin-transporting species. Irrespective of the oxidation state of tin in the fluid, cassiterite precipitates due to reaction of the hydrothermal fluid with the wall rock (greisen or skarn formation), dilution (mixing with meteoric water) or a decrease in the HCl activity in the aqueous liquid by boiling. A redox reaction is only required for tin transported as Sn(II) to be converted to Sn(IV).

  16. Low- and high-frequency Raman investigations on caffeine: polymorphism, disorder and phase transformation.

    Science.gov (United States)

    Hédoux, Alain; Decroix, Anne-Amandine; Guinet, Yannick; Paccou, Laurent; Derollez, Patrick; Descamps, Marc

    2011-05-19

    Raman investigations are carried out both in crystalline forms of caffeine and during the isothermal transformation of the orientationally disordered form I into the stable form II at 363 K. The time dependence of the Raman spectrum exhibits no significant change in the intramolecular regime (above 100 cm(-1)), resembling the spectrum of the liquid state. By contrast, significant changes are observed below 100 cm(-1), and the low-frequency spectra of forms I and II are observed to be different from that of the liquid. The temperature dependence of the 5-600 cm(-1) spectrum gives information on the static disorder through the analysis of collective motions, while information on dynamic disorder are obtained from the study of the 555 cm(-1) band corresponding to internal vibrations in the pyrimidine ring. This analysis indubitably reveals that form II is also orientationally disordered with a local molecular arrangement that mimics that in form I and the liquid state. The comparison of the low-frequency spectra recorded in theophylline and form II of caffeine allows one to describe the stable form of caffeine from the packing arrangement of anhydrous theophylline with the consideration of reorientational molecular disorder. © 2011 American Chemical Society

  17. Micro-Raman investigations of InN-GaN core-shell nanowires on Si (111) substrate

    Energy Technology Data Exchange (ETDEWEB)

    Sangeetha, P.; Ramakrishnan, V. [Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai-625 021 (India); Jeganathan, K. [Centre for Nanoscience and Nanotechnology, School of Physics, Bharathidasan University, Tiruchirappalli-620 024 (India)

    2013-06-15

    The electron-phonon interactions in InN-GaN core-shell nanowires grown by plasma assisted- molecular beam epitaxy (MBE) on Si (111) substrate have been analysed using micro-Raman spectroscopic technique with the excitation wavelength of 633, 488 and 325 nm. The Raman scattering at 633 nm reveals the characteristic E{sub 2} (high) and A{sub 1} (LO) phonon mode of InN core at 490 and 590 cm{sup -1} respectively and E{sub 2} (high) phonon mode of GaN shell at 573 cm{sup -1}. The free carrier concentration of InN core is found to be low in the order {approx} 10{sup 16} cm{sup -3} due to the screening of charge carriers by thin GaN shell. Diameter of InN core evaluated using the spatial correlation model is consistent with the transmission electron microscopic measurement of {approx}15 nm. The phonon-life time of core-shell nanowire structure is estimated to be {approx}0.4 ps. The micro-Raman mapping and its corresponding localised spectra for 325 nm excitation exhibit intense E{sub 2} (high) phonon mode of GaN shell at 573 cm{sup -1} as the decrease of laser interaction length and the signal intensity is quenched at the voids due to high spacing of NWs.

  18. Micro-Raman investigations of InN-GaN core-shell nanowires on Si (111) substrate

    Science.gov (United States)

    Sangeetha, P.; Jeganathan, K.; Ramakrishnan, V.

    2013-06-01

    The electron-phonon interactions in InN-GaN core-shell nanowires grown by plasma assisted- molecular beam epitaxy (MBE) on Si (111) substrate have been analysed using micro-Raman spectroscopic technique with the excitation wavelength of 633, 488 and 325 nm. The Raman scattering at 633 nm reveals the characteristic E2 (high) and A1 (LO) phonon mode of InN core at 490 and 590 cm-1 respectively and E2 (high) phonon mode of GaN shell at 573 cm-1. The free carrier concentration of InN core is found to be low in the order ˜ 1016 cm-3 due to the screening of charge carriers by thin GaN shell. Diameter of InN core evaluated using the spatial correlation model is consistent with the transmission electron microscopic measurement of ˜15 nm. The phonon-life time of core-shell nanowire structure is estimated to be ˜0.4 ps. The micro-Raman mapping and its corresponding localised spectra for 325 nm excitation exhibit intense E2 (high) phonon mode of GaN shell at 573 cm-1 as the decrease of laser interaction length and the signal intensity is quenched at the voids due to high spacing of NWs.

  19. Micro-Raman investigations of InN-GaN core-shell nanowires on Si (111 substrate

    Directory of Open Access Journals (Sweden)

    P. Sangeetha

    2013-06-01

    Full Text Available The electron-phonon interactions in InN-GaN core-shell nanowires grown by plasma assisted- molecular beam epitaxy (MBE on Si (111 substrate have been analysed using micro-Raman spectroscopic technique with the excitation wavelength of 633, 488 and 325 nm. The Raman scattering at 633 nm reveals the characteristic E2 (high and A1 (LO phonon mode of InN core at 490 and 590 cm−1 respectively and E2 (high phonon mode of GaN shell at 573 cm−1. The free carrier concentration of InN core is found to be low in the order ∼ 1016 cm−3 due to the screening of charge carriers by thin GaN shell. Diameter of InN core evaluated using the spatial correlation model is consistent with the transmission electron microscopic measurement of ∼15 nm. The phonon-life time of core-shell nanowire structure is estimated to be ∼0.4 ps. The micro-Raman mapping and its corresponding localised spectra for 325 nm excitation exhibit intense E2 (high phonon mode of GaN shell at 573 cm−1 as the decrease of laser interaction length and the signal intensity is quenched at the voids due to high spacing of NWs.

  20. Micro-Raman investigations of InN-GaN core-shell nanowires on Si (111) substrate

    International Nuclear Information System (INIS)

    Sangeetha, P.; Ramakrishnan, V.; Jeganathan, K.

    2013-01-01

    The electron-phonon interactions in InN-GaN core-shell nanowires grown by plasma assisted- molecular beam epitaxy (MBE) on Si (111) substrate have been analysed using micro-Raman spectroscopic technique with the excitation wavelength of 633, 488 and 325 nm. The Raman scattering at 633 nm reveals the characteristic E 2 (high) and A 1 (LO) phonon mode of InN core at 490 and 590 cm −1 respectively and E 2 (high) phonon mode of GaN shell at 573 cm −1 . The free carrier concentration of InN core is found to be low in the order ∼ 10 16 cm −3 due to the screening of charge carriers by thin GaN shell. Diameter of InN core evaluated using the spatial correlation model is consistent with the transmission electron microscopic measurement of ∼15 nm. The phonon-life time of core-shell nanowire structure is estimated to be ∼0.4 ps. The micro-Raman mapping and its corresponding localised spectra for 325 nm excitation exhibit intense E 2 (high) phonon mode of GaN shell at 573 cm −1 as the decrease of laser interaction length and the signal intensity is quenched at the voids due to high spacing of NWs.

  1. Synthesis, structure, spectroscopic investigations, and computational studies of optically pure β-ketoamide

    International Nuclear Information System (INIS)

    Mtat, D.; Touati, R.; Guerfel, T.; Walha, K.; Ben Hassine, B.

    2016-01-01

    Chemical preparation, X-ray single crystal diffraction, IR and NMR spectroscopic investigations of a novel nonlinear optical organic compound (C 17 H 22 NO 2 Cl) are described. The compound crystallizes in the orthorhombic system with the non-centrosymmetric sp. gr. P2 1 2 1 2 1 . In the crystal structure, molecules are interconnected by N–H…O hydrogen bonds forming infinite chains along a axis. The Hirshfeld surface and associated fingerprint plots of the compound are presented to explore the nature of intermolecular interactions and their relative contributions in building the solid-state architecture. The molecular HOMO–LUMO compositions and their respective energy gaps are also drawn to explain the activity of the compound. The first hyperpolarizability β tot of the title compound is determined using DFT calculations. The optical properties are also investigated by UV–Vis absorption spectrum.

  2. An adiabatic spectroscopic investigation of the CsRb system in ground and numerous excited states

    Science.gov (United States)

    Souissi, Hanen; Jellali, Soulef; Maha, Chaieb; Habli, Héla; Oujia, Brahim; Gadéa, Florent Xavier

    2017-10-01

    Via ab-initio approximations, we investigate the electronic and structural features of the CsRb molecule. Adiabatic potential energy curves of 261,3Σ+, 181,3Π and 61,3Δ electronic states with their derived spectroscopic constants as well as vibrational levels spacing have been carried out and well explained. Our approach is founded on an Effective Core Potential (ECP) describing the valence electrons of the system. Using a large Gaussian basis set, the full valence Configuration Interaction can be applied easily on the two-effective valence electrons of the CsRb system. Furthermore, a detailed analysis of the electric dipolar properties has been made through the investigation of both permanent and transition dipole moments (PDM and TDM). It is significant that the ionic character connected with electron transfer that is linked to Cs+ Rb- state has been clearly illustrated in the adiabatic permanent dipole moment.

  3. Synthesis, structure, spectroscopic investigations, and computational studies of optically pure β-ketoamide

    Energy Technology Data Exchange (ETDEWEB)

    Mtat, D.; Touati, R. [Université de Monastir, Laboratoire de Synthèse Organique Asymétrique et Catalyse Homogène (UR11ES56), Faculté des Sciences (Tunisia); Guerfel, T., E-mail: taha-guerfel@yahoo.fr [Université de Kairouan, Laboratoire d’Electrochimie, Matériaux et Environnement (Tunisia); Walha, K. [Université de Sfax, M.E.S.Lab. Faculté des Sciences de Sfax (Tunisia); Ben Hassine, B. [Université de Monastir, Laboratoire de Synthèse Organique Asymétrique et Catalyse Homogène (UR11ES56), Faculté des Sciences (Tunisia)

    2016-12-15

    Chemical preparation, X-ray single crystal diffraction, IR and NMR spectroscopic investigations of a novel nonlinear optical organic compound (C{sub 17}H{sub 22}NO{sub 2}Cl) are described. The compound crystallizes in the orthorhombic system with the non-centrosymmetric sp. gr. P2{sub 1}2{sub 1}2{sub 1}. In the crystal structure, molecules are interconnected by N–H…O hydrogen bonds forming infinite chains along a axis. The Hirshfeld surface and associated fingerprint plots of the compound are presented to explore the nature of intermolecular interactions and their relative contributions in building the solid-state architecture. The molecular HOMO–LUMO compositions and their respective energy gaps are also drawn to explain the activity of the compound. The first hyperpolarizability β{sub tot} of the title compound is determined using DFT calculations. The optical properties are also investigated by UV–Vis absorption spectrum.

  4. Spectroscopic investigation of the vibrational quasi-continuum arising from internal rotation of a methyl group

    Energy Technology Data Exchange (ETDEWEB)

    Hougen, J.T. [NIST, Gaithersburg, MD (United States)

    1993-12-01

    The goal of this project is to use spectroscopic techniques to investigate in detail phenomena involving the vibrational quasi-continuum in a simple physical system. Acetaldehyde was chosen for the study because: (i) methyl groups have been suggested to be important promotors of intramolecular vibrational relaxation, (ii) the internal rotation of a methyl group is an easily describle large-amplitude motion, which should retain its simple character even at high levels of excitation, and (iii) the aldehyde carbonyl group offers the possibility of both vibrational and electronic probing. The present investigation of the ground electronic state has three parts: (1) understanding the {open_quotes}isolated{close_quotes} internal-rotation motion below, at, and above the top of the torsional barrier, (2) understanding in detail traditional (bond stretching and bending) vibrational fundamental and overtone states, and (3) understanding interactions involving states with multiquantum excitations of at least one of these two kinds of motion.

  5. Intermolecular interaction of fosinopril with bovine serum albumin (BSA): The multi-spectroscopic and computational investigation.

    Science.gov (United States)

    Zhou, Kai-Li; Pan, Dong-Qi; Lou, Yan-Yue; Shi, Jie-Hua

    2018-04-16

    The intermolecular interaction of fosinopril, an angiotensin converting enzyme inhibitor with bovine serum albumin (BSA), has been investigated in physiological buffer (pH 7.4) by multi-spectroscopic methods and molecular docking technique. The results obtained from fluorescence and UV absorption spectroscopy revealed that the fluorescence quenching mechanism of BSA induced by fosinopril was mediated by the combined dynamic and static quenching, and the static quenching was dominant in this system. The binding constant, K b , value was found to lie between 2.69 × 10 3 and 9.55 × 10 3  M -1 at experimental temperatures (293, 298, 303, and 308 K), implying the low or intermediate binding affinity between fosinopril and BSA. Competitive binding experiments with site markers (phenylbutazone and diazepam) suggested that fosinopril preferentially bound to the site I in sub-domain IIA on BSA, as evidenced by molecular docking analysis. The negative sign for enthalpy change (ΔH 0 ) and entropy change (ΔS 0 ) indicated that van der Waals force and hydrogen bonds played important roles in the fosinopril-BSA interaction, and 8-anilino-1-naphthalenesulfonate binding assay experiments offered evidence of the involvements of hydrophobic interactions. Moreover, spectroscopic results (synchronous fluorescence, 3-dimensional fluorescence, and Fourier transform infrared spectroscopy) indicated a slight conformational change in BSA upon fosinopril interaction. Copyright © 2018 John Wiley & Sons, Ltd.

  6. Spectroscopic Parameter and Molecular Constant Investigations on Low-Lying States of BeF Radical

    Directory of Open Access Journals (Sweden)

    Jin Feng Sun

    2012-02-01

    Full Text Available The potential energy curves (PECs of X2Σ+, A2Πr and B2Σ+ states of BeF radical have been investigated using the complete active space self-consistent-field (CASSCF method, followed by the highly accurate valence internally contracted multireference configuration interaction (MRCI approach at the correlation-consistent basis sets, cc-pV5Z for Be and aug-cc-pV6Z for F. Based on the PECs of X2Σ+, A2Πr and B2Σ+ states, the spectroscopic parameters (De, Re, ωe, ωeχe, αe and Be have also been determined in the present work. With the PECs determined at the present level of theory, vibrational states have been predicted for each state when the rotational quantum number J equals zero (J = 0. The vibrational levels, inertial rotation and centrifugal distortion constants are determined for the three states, and the classical turning points are also calculated for the X2Σ+ state. Compared with the available experiments and other theories, it can be seen that the present spectroscopic parameter and molecular constant results are more fully in agreement with the experimental findings.

  7. Spectroscopic investigation on the interaction of titanate nanotubes with bovine serum albumin

    International Nuclear Information System (INIS)

    Zhao, L.Z.; Zhao, Y.S.; Teng, H.H.; Shi, S.Y.; Ren, B.X.

    2014-01-01

    In order to understand the transport mechanism and evaluate the biological safety of titanate nanotubes, the interactions of titanate nanotubes (TNTs) with bovine serum albumin (BSA) were investigated by applying spectroscopic methods under simulated physiological conditions. After taking into account the inner filter effect, the fluorescence intensity of BSA was found to be significantly enhanced by the presence of TNTs, indicating that the microenvironment of tryptophan and tyrosine residues in BSA became more hydrophobic. In addition, the absorption spectra of BSA showed a hyperchromic effect around 280 nm as the concentration of TNTs increased, suggesting that TNTs changed the microenvironment of the tryptophan and tyrosine residues. This is consistent with the results from fluorescence spectroscopy studies. However, circular dichroism spectroscopy revealed that no significant conformational change in BSA occurred during the interaction. We believe that Trp-213 was buried more compactly in the internal hydrophobic region, and hydrophobicity increased around Trp-134 with increasing TNTs concentration. From a spectroscopic point of view, this work elucidates the interaction mechanism of titanate nanotubes with BSA, and the methods used in this paper can also be applied to explore the molecular mechanism underlying toxicity of other nanomaterials. (authors)

  8. Spectroscopic investigations of lanthanides and actinides using simultaneous LIF and photoionization techniques

    International Nuclear Information System (INIS)

    Shah, M.L.

    2017-01-01

    Laser-induced fluorescence (LIF) and laser-induced photoionization (LIP) are powerful spectroscopic techniques individually. These techniques have been used extensively for studying the atomic spectra. The potential of these two techniques increases enormously when used simultaneously because of their complimentary nature. Among these two, the resonance ionization spectroscopy is most sensitive, but in some cases the spectra obtained using this photoionization technique can provide the incomplete atomic energy levels information. The complete energy level information can be obtained when both the LIF and LIP techniques are used simultaneously. These techniques have been developed in our laboratory. By employing together both the LIF and LIP techniques for simultaneous detection and utilization of LIF and LIP signals not only helped in developing new methodologies but also helped in getting complete spectral information apart from the measurements of atomic parameters. For the first time, laser-induced fluorescence and laser-induced photoionization techniques are used simultaneously for the spectroscopic investigations of atoms of lanthanides and actinides. The density matrix (DM) formalism is used to validate the experimental results. (author)

  9. In Situ Raman Spectroscopic Observations of Gas-Saturated Rising Oil droplets: Simulation with Decane as an Oil-Equivalent Substitute

    Science.gov (United States)

    Peltzer, E. T.; Walz, P. M.; Brewer, P. G.

    2016-02-01

    Oil droplets rising from the sea floor, whether from seeps or well leakage, contain very large quantities of dissolved gas that profoundly affects their density and critical oil-water interfacial characteristics. The primary dissolved gas is methane which may be up to 30% of the molar volume. This can create a hydrate skin as the methane gas is shed from the oil as it rises through the water column, thus decreasing in pressure and increasing in temperature, and steadily changing the rising droplet buoyancy. We have explored this phenomenon by executing controlled ROV based experiments with a "bubble cup" technique in which a small volume of gas saturated decane (saturated with pure methane, a mix of methane and nitrogen , or a mix of methane and CO2) is interrogated by laser Raman spectroscopy. The use of decane as an oil "substitute" is required since natural oil samples are highly fluorescent due to the presence of polycyclic aromatic hydrocarbons. We have devised Matlab techniques for extracting the spectroscopic dissolved methane signal from the thicket of decane peaks that surround it. We have directly observed the rate at which gases are lost from the "oil" per unit area at depths in the water column that are both within and outside the hydrate forming phase boundary. We have compared the behavior of both a non-hydrate forming dissolved gas (nitrogen) with CO2 where the hydrate phase boundary is at significantly shallower depth. The results indicate complex interfacial behavior and physical chemistry. We did not observe direct gas bubble formation on the decane outer surface but did observe gas bubble formation within the oil droplets as they rose through the water column. Because there are significant energy barriers for homogeneous bubble formation within the decane phase, we took this as evidence of significant gas super-saturation within the oil droplet. The gas loss rates increased significantly in all cases when the hydrate phase boundary was crossed.

  10. Impact of leach on lead vanado-iodoapatite [Pb5(VO4)3I]: An infrared and Raman spectroscopic study

    International Nuclear Information System (INIS)

    Zhang Ming; Maddrell, E.R.; Abraitis, P.K.; Salje, E.K.H.

    2007-01-01

    Structural changes in lead vanado-iodoapatite [Pb 5 (VO 4 ) 3 I], leached in KOH/KCO 3 H buffer solution at 90 deg. C, were investigated using infrared (IR) and Raman spectroscopy. The untreated material shows characteristic phonon bands in three wavenumber regions (50-250, 300-500 and 750-870 cm -1 ). In comparison with a natural apatite, the replacement of phosphate by vanadium in the apatite structure leads to stretching and bending vibrations of the structural tetrahedra shift to lower frequencies. The leached samples all show extra bands between 3000 and 3600 cm -1 , characterised by two features: a broad tail and two sharp absorption bands near 3490 and 3538 cm -1 . The former is attributed to the H 2 O species absorbed by the gains or located between grain boundaries, whereas the latter two bands, which have the similar frequencies as those of hydroxyls in fluorapatite, are assigned as OH species which substitutes iodine in the leached materials. The leached samples also show an extra Raman band near 1058 cm -1 and IR bands near 1370 and 1420 cm -1 , which are the characteristic vibrations of CO 3 units. The uncorrelated relative intensities between CO 3 and OH bands and the absence of the characteristic C-OH vibrations (near 1017 and 1300 cm -1 ) of the HCO 3 ion in the Raman spectra indicate that hydrogen- and carbon-related species mainly exist in the form of CO 3 and OH rather than HCO 3 . CO 3 ions could be incorporated into the tetrahedral sites by substitution of VO 4 (B-type substitution) as a result of the leached-induced loss of vanadium

  11. Detection of latent prints by Raman imaging

    Science.gov (United States)

    Lewis, Linda Anne [Andersonville, TN; Connatser, Raynella Magdalene [Knoxville, TN; Lewis, Sr., Samuel Arthur

    2011-01-11

    The present invention relates to a method for detecting a print on a surface, the method comprising: (a) contacting the print with a Raman surface-enhancing agent to produce a Raman-enhanced print; and (b) detecting the Raman-enhanced print using a Raman spectroscopic method. The invention is particularly directed to the imaging of latent fingerprints.

  12. Spectroscopic (vibrational, NMR and UV-vis.) and quantum chemical investigations on 4-hexyloxy-3-methoxybenzaldehyde.

    Science.gov (United States)

    Abbas, Ashgar; Gökce, Halil; Bahçeli, Semiha

    2016-01-05

    In this study, the 4-hexyloxy-3-methoxybenzaldehyde compound as one of the derivatives of vanillin which is a well known flavoring agent, C14H20O3, has been investigated by experimentally and extensively utilizing density functional theory (DFT) at the B3LYP/6-311++G(d,p) level. In this context, the optimized geometry, vibrational frequencies, (1)H and (13)C NMR chemical shifts, UV-vis. (in gas phase and in methanol solvent) spectra, HOMO-LUMO analysis, molecular electrostatic potential (MEP), thermodynamic parameters and atomic charges of 4-hexyloxy-3-methoxybenzaldehyde have been calculated. In addition, theoretically predicted IR, Raman and UV-vis. (in gas phase and in methanol solvent) spectra of the mentioned molecule have been constructed. The results calculated were compared with the experimental data. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Microscopic description of protein thermostabilization mechanisms with disaccharides from Raman spectroscopy investigations

    Energy Technology Data Exchange (ETDEWEB)

    Hedoux, A; Affouard, F; Descamps, M; Guinet, Y; Paccou, L [Laboratoire de Dynamique et Structure des Materiaux Moleculaires UMR CNRS 8024, Universite de Lille 1, UFR de Physique, Batiment P5, 59 655 Villeneuve d' Ascq Cedex (France)

    2007-05-23

    The mechanisms of protein thermostabilization by sugar were analysed for three disaccharides (maltose, sucrose and trehalose) characterized by the same chemical formula (C{sub 12}H{sub 22}O{sub 11}). Raman scattering investigations simultaneously carried out in the low-frequency range and in the amide I band region provide a microscopic description of the process of protein thermal denaturation. From this detailed description, the influence of sugar on this process was analysed. The principal effect of sugars is to stabilize the tertiary structure, in which the biomolecule preserves its native conformation, through a strengthening of O-H interactions. This study shows that the bioprotective properties of sugars are mainly based on interactions between water and sugar. The exceptional properties of trehalose to preserve the native state of lysozyme by heating can be associated with its capability to distort the tetra-bonded hydrogen bond network of water.

  14. Calibration transfer of a Raman spectroscopic quantification method for the assessment of liquid detergent compositions between two at-line instruments installed at two liquid detergent production plants.

    Science.gov (United States)

    Brouckaert, D; Uyttersprot, J-S; Broeckx, W; De Beer, T

    2017-09-01

    Calibration transfer of partial least squares (PLS) quantification models is established between two Raman spectrometers located at two liquid detergent production plants. As full recalibration of existing calibration models is time-consuming, labour-intensive and costly, it is investigated whether the use of mathematical correction methods requiring only a handful of standardization samples can overcome the dissimilarities in spectral response observed between both measurement systems. Univariate and multivariate standardization approaches are investigated, ranging from simple slope/bias correction (SBC), local centring (LC) and single wavelength standardization (SWS) to more complex direct standardization (DS) and piecewise direct standardization (PDS). The results of these five calibration transfer methods are compared reciprocally, as well as with regard to a full recalibration. Four PLS quantification models, each predicting the concentration of one of the four main ingredients in the studied liquid detergent composition, are aimed at transferring. Accuracy profiles are established from the original and transferred quantification models for validation purposes. A reliable representation of the calibration models performance before and after transfer is thus established, based on β-expectation tolerance intervals. For each transferred model, it is investigated whether every future measurement that will be performed in routine will be close enough to the unknown true value of the sample. From this validation, it is concluded that instrument standardization is successful for three out of four investigated calibration models using multivariate (DS and PDS) transfer approaches. The fourth transferred PLS model could not be validated over the investigated concentration range, due to a lack of precision of the slave instrument. Comparing these transfer results to a full recalibration on the slave instrument allows comparison of the predictive power of both Raman

  15. Combined quantum chemical density functional theory and spectroscopic Raman and UV-vis-NIR study of oligothienoacenes with five and seven rings.

    Science.gov (United States)

    Osuna, Reyes Malavé; Zhang, Xinnan; Matzger, Adam Jay; Hernandez, Víctor; López Navarrete, Juan Teodomiro

    2006-04-20

    In this article, we report the characterization of novel oligothienoacenes with five and seven fused thiophene rings, materials with potential applications in organic electronics. In contrast to usual alpha-linked oligothiophenes, these fused oligothiophenes have a larger band gap than most semiconductors currently used in the fabrication of organic field-effect transistors (OFETs) and therefore they are expected to be more stable in air. The synthesis of these fused-ring oligomers was motivated by the notion that a more rigid and planar structure should reduce defects (such as torsion about single bonds between alpha-linked units or S-syn defects) and thus improve conjugation for better charge-carrier mobility. The conjugational properties of these two molecular materials have been investigated by means of FT-Raman spectroscopy, revealing that conjugation still increases in passing from the five-ring oligomer to that with seven-rings. DFT and TDDFT quantum chemical calculations have been performed, at the B3LYP/6-31G level, to assess information regarding the minimum-energy molecular structure, topologies, and absolute energies of the frontier molecular orbitals (MOs.) around the gap, vibrational normal modes related to the main Raman features, and vertical one-electron excitations giving rise to the main optical absorptions.

  16. Interactions between {beta}-carboline alkaloids and bovine serum albumin: Investigation by spectroscopic approach

    Energy Technology Data Exchange (ETDEWEB)

    Nafisi, Shohreh, E-mail: drshnafisi@gmail.com [Department of Chemistry, Islamic Azad University, Central Tehran Branch (IAUCTB), Tehran (Iran, Islamic Republic of); Panahyab, Ataollah [Department of Chemistry, Islamic Azad University, Central Tehran Branch (IAUCTB), Tehran (Iran, Islamic Republic of); Bagheri Sadeghi, Golshan [Department of Biology, Islamic Azad University, Science and Research Branch, Tehran (Iran, Islamic Republic of)

    2012-09-15

    {beta}-Carboline alkaloids are present in medicinal plants such as Peganum harmala L. that have been used as folk medicine in anticancer therapy. BSA is the major soluble protein constituent of the circulatory system, and has many physiological functions including the transport of a variety of compounds. This study is the first attempt to investigate the binding of {beta}-carboline alkaloids to BSA by using a constant protein concentration and varying drug concentrations at pH 7.2. FTIR and UV-Vis spectroscopic methods were used to analyze the binding modes of {beta}-carboline alkaloids, the binding constants and the effects of drug complexation on BSA stability and conformation. Spectroscopic evidence showed that {beta}-carboline alkaloids bind BSA via hydrophobic interaction and van der Waals contacts along with H-bonding with the -NH groups, with overall binding constants of K{sub harmine-BSA}=2.04 Multiplication-Sign 10{sup 4} M{sup -1}, K{sub tryptoline-BSA}=1.2 Multiplication-Sign 10{sup 4} M{sup -1}, K{sub harmaline-BSA}=5.04 Multiplication-Sign 10{sup 3} M{sup -1}, K{sub harmane-BSA}=1.41 Multiplication-Sign 10{sup 3} M{sup -1} and K{sub harmalol-BSA}=1.01 Multiplication-Sign 10{sup 3} M{sup -1}, assuming that there is one drug molecule per protein. The BSA secondary structure was altered with a major decrease of {alpha}-helix from 64% (free protein) to 59% (BSA-harmane), 56% (BSA-harmaline and BSA-harmine), 55% (BSA-tryptoline), 54% (BSA-harmalol) and {beta}-sheet from 15% (free protein) to 6-8% upon {beta}-carboline alkaloids complexation, inducing a partial protein destabilization. - Highlights: Black-Right-Pointing-Pointer We model the binding of {beta}-carboline alkaloids to BSA by using the spectroscopic methods. Black-Right-Pointing-Pointer We investigate the effects of drug complexation on BSA stability and conformation. Black-Right-Pointing-Pointer A partial protein destabilization occurred at high alkaloids concentration. Black

  17. Interactions between β-carboline alkaloids and bovine serum albumin: Investigation by spectroscopic approach

    International Nuclear Information System (INIS)

    Nafisi, Shohreh; Panahyab, Ataollah; Bagheri Sadeghi, Golshan

    2012-01-01

    β-Carboline alkaloids are present in medicinal plants such as Peganum harmala L. that have been used as folk medicine in anticancer therapy. BSA is the major soluble protein constituent of the circulatory system, and has many physiological functions including the transport of a variety of compounds. This study is the first attempt to investigate the binding of β-carboline alkaloids to BSA by using a constant protein concentration and varying drug concentrations at pH 7.2. FTIR and UV–Vis spectroscopic methods were used to analyze the binding modes of β-carboline alkaloids, the binding constants and the effects of drug complexation on BSA stability and conformation. Spectroscopic evidence showed that β-carboline alkaloids bind BSA via hydrophobic interaction and van der Waals contacts along with H-bonding with the –NH groups, with overall binding constants of K harmine–BSA =2.04×10 4 M −1 , K tryptoline–BSA =1.2×10 4 M −1 , K harmaline–BSA =5.04×10 3 M −1 , K harmane–BSA =1.41×10 3 M −1 and K harmalol–BSA =1.01×10 3 M −1 , assuming that there is one drug molecule per protein. The BSA secondary structure was altered with a major decrease of α-helix from 64% (free protein) to 59% (BSA–harmane), 56% (BSA–harmaline and BSA–harmine), 55% (BSA–tryptoline), 54% (BSA–harmalol) and β-sheet from 15% (free protein) to 6–8% upon β-carboline alkaloids complexation, inducing a partial protein destabilization. - Highlights: ► We model the binding of β-carboline alkaloids to BSA by using the spectroscopic methods. ► We investigate the effects of drug complexation on BSA stability and conformation. ► A partial protein destabilization occurred at high alkaloids concentration. ► Alkaloids bind BSA via hydrophobic interactions and H-bonding with the ---NH groups. ► BSA can be considered as a good carrier for transportation of β-carboline alkaloids.

  18. The interaction between 4-aminoantipyrine and bovine serum albumin: Multiple spectroscopic and molecular docking investigations

    International Nuclear Information System (INIS)

    Teng Yue; Liu Rutao; Li Chao; Xia Qing; Zhang Pengjun

    2011-01-01

    4-Aminoantipyrine (AAP) is widely used in the pharmaceutical industry, in biochemical experiments and in environmental monitoring. AAP as an aromatic pollutant in the environment poses a great threat to human health. To evaluate the toxicity of AAP at the protein level, the effects of AAP on bovine serum albumin (BSA) were investigated by multiple spectroscopic techniques and molecular modeling. After the inner filter effect was eliminated, the experimental results showed that AAP effectively quenched the intrinsic fluorescence of BSA via static quenching. The number of binding sites, the binding constant, the thermodynamic parameters and binding subdomain were measured, and indicated that AAP could spontaneously bind with BSA on subdomain IIIA through electrostatic forces. Molecular docking results revealed that AAP interacted with the Glu 488 and Glu 502 residues of BSA. Furthermore, the conformation of BSA was demonstrably changed in the presence of AAP. The skeletal structure of BSA loosened, exposing internal hydrophobic aromatic ring amino acids and peptide strands to the solution.

  19. DC diode sputtering of titanium: determination of optimal deposition conditions by electrical and spectroscopic investigations

    International Nuclear Information System (INIS)

    Poitevin, J.M.; Lemperiere, G.; Fourrier, C.

    1976-01-01

    An argon DC glow discharge in a diode sputtering system fitted with a titanium cathode is investigated. The first results fix the boundaries of good working conditions for the discharge; mathematical relations are established for the pressure range 40 to 120 mTorr, anode-cathode lengths from 15 to 60 mm and current densities from 0.6 to 2 mA cm -2 . The deposition rate is found to be proportional to the electrical power if the product pd is kept constant, but the ratio of the deposition rate to discharge power exhibits a maximum for d approximately equal 1.5 lsub(e). Spectroscopic studies of the discharge close to the substrate surface show that the intensity of some arc and spark lines of titanium is also proportional to the deposition rate. Emission spectroscopy shows that hydrogen is produced and quickly pumped during the presputtering stage; its evacuation is necessary to obtain good metallic films. (author)

  20. Raman scattering investigation of Bi2Te3 hexagonal nanoplates prepared by a solvothermal process in the absence of NaOH

    International Nuclear Information System (INIS)

    Liang Yujie; Wang Wenzhong; Zeng Baoqing; Zhang Guling; Huang Jing; Li Jin; Li Te; Song Yangyang; Zhang Xiuyu

    2011-01-01

    Research highlights: → Hexagonal Bi 2 Te 3 thin nanoplates were synthesized by a simple solvothermal method. → Optical properties of the nanoplates were investigated by micro-Raman spectroscopy. → Infrared (IR) active mode (A 1u ) is greatly activated in Raman scattering spectrum. → Infrared (IR) active mode (A 1u ) shows up in Raman spectrum of hexagonal nanoplates. → Raman spectrum clearly shows crystal symmetry breaking of hexagonal nanoplates. - Abstract: Hexagonal Bi 2 Te 3 nanoplates were synthesized by a simple solvothermal process in the absence of NaOH. The composition, morphology and size of the as-prepared products were characterized by powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). Raman scattering optical properties of the as-prepared Bi 2 Te 3 nanoplates were investigated by micro-Raman spectroscopy. The Raman spectrum shows that infrared (IR) active mode (A 1u ), which must be odd parity and is Raman forbidden for bulk crystal due to its inversion symmetry, is greatly activated and shown up clearly in Raman scattering spectrum. We attribute the appearance of infrared active (A 1u ) in Raman spectrum to crystal symmetry breaking of Bi 2 Te 3 hexagonal nanoplates. The as-grown Bi 2 Te 3 hexagonal nanoplates, exhibiting novel Raman optical properties compared with bulk crystals, may find potential applications in thermoelectric devices.

  1. Charge transfer in carbon nanotube actuators investigated using in situ Raman spectroscopy

    International Nuclear Information System (INIS)

    Gupta, S.; Hughes, M.; Windle, A.H.; Robertson, J.

    2004-01-01

    Charge transfer dynamics on the surface of single-wall carbon nanotube sheets is investigated using in situ Raman spectroscopy in order to understand the actuation mechanism of an electrochemical actuator and to determine associated parameters. We built an actuator from single-wall carbon nanotube mat and studied its actuation in several alkali metal (Li, Na, and K) and alkaline earth (Ca) halide and sulfate solutions in order to clarify the role of counterion as mobile ions in the film. The variation of bonding with applied potential was monitored using in situ Raman spectroscopy. This is because Raman can detect changes in C-C bond length: the radial breathing mode at ∼190 cm-1 varies inversely with the nanotube diameter, and the G band at ∼1590 cm-1 varies with the axial bond length. In addition, the intensities of both the modes vary with the emptying/depleting or filling of the bonding and antibonding states due to electrochemical charge injection. We discussed the variation of peak height and wave numbers of these modes providing valuable information concerning electrochemical charge injection on the carbon nanotube mat surface. We found in-plane microscopic compressive strain (∼-0.25%) and the equivalent charge transfer per carbon atom (f c ∼-0.005) as an upper bound for the actuators studied hereby. It is demonstrated that though the present analysis does comply with the proposition for the actuation principle made earlier, the quantitative estimates are significantly lower if compared with those of reported values. Furthermore, the extent of variation, i.e., coupled electro-chemo-mechanical response of single-wall carbon nanotubes (SWNT) mat depended upon the type of counterion used (Group I versus Group II). The cyclic voltammetry and ac electrochemical impedance spectroscopy results were described briefly, which help to demonstrate well-developed capacitive behavior of SWNT mat and to estimate the specific capacitances as well. Summarizing, the

  2. Raman spectroscopy in the analysis of cellulose nanomaterials

    Science.gov (United States)

    Umesh P. Agarwal

    2017-01-01

    Cellulose nanomaterials (CNs) are new types of materials derived from celluloses and offer unique challenges and opportunities for Raman spectroscopic investigations. CNs can be classified into the categories of cellulose nanocrystals (CNCs, also known as cellulose whisker) and cellulose nanofibrils (CNFs, also known as nanofibrillated cellulose or NFCs) which when...

  3. Thermal structural evolutions of DMPC-water biomimetic systems investigated by Raman Spectroscopy.

    Science.gov (United States)

    Fasanella, A; Cosentino, K; Beneduci, A; Chidichimo, G; Cazzanelli, E; Barberi, R C; Castriota, M

    2018-06-01

    Many cell membranes of living organisms can be represented as phospholipid bilayers immersed into a water environment. The physical-chemical interactions at the membranes/water interface are responsible for the stabilization of the membranes. In addition, the drug efficiency, the pharmaceutical mechanism and the improvement of the drug design can be addressed to the interactions between the membranes-water interface with the drug and to the membrane-drug interface. In this framework, it is important to find membranes models able to simulate and simultaneously simplify the biological systems to better understand both physical and chemical interactions at the interface level. Dimyristoylphosphatidylcholine (DMPC) is a synthetic phospholipid used in order to make Multilamellar Vesicle (MLV), Large Unilamellar Vesicle (LUV) and Giant Unilamellar Vesicle (GUV). In order to understand the mechanisms of vesicle formation, we have analyzed mixtures of DMPC and water by micro-Raman spectroscopy at different temperatures in the range between 10 and 35 °C. Particularly, we analyzed the temperature dependence of the CN vibrational frequency, which appears well correlated to the order degree of the various phases. These investigations, beyond the determination of phospholipid hydrocarbon chains order, provide information about the conformation of the lipid membranes. We have identified the mixture of DMPC/water that is best suited for Raman studies and can be used as an in-vitro model for biological systems. A peculiar frequency shift across the transition gel-ripple-liquid crystalline phases has been proposed as a useful diagnostic marker to detect the "order degree" and subsequently the phases of biomimetic membranes made by DMPC. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Macroscopic and spectroscopic investigations on the immobilization of radionuclides by hardened cement paste

    International Nuclear Information System (INIS)

    Wieland, E.; Bonhoure, I.; Tits, J.; Scheidegger, A.M.; Bradbury, M.H.

    2002-01-01

    The uptake of safety-relevant radionuclides was studied using a combination of macroscopic (wet chemistry) and spectroscopic (X-ray absorption fine structure (XAFS) spectroscopy) techniques with the aim of gaining a mechanistic understanding of the uptake processes on hardened cement paste (HCP) and deducing robust sets of sorption values. HCP contains impurities of metal cations in the ppb to ppm concentration range. As a consequence, the inventories of stable isotopes are expected to be significant in a cementitious near-field and may even exceed the radionuclide inventories of the waste matrix for many safety-relevant radioelements. In view of the significant inventories of stable isotopes, it is suggested that isotopic exchange - replacement of stable isotopes by their radioactive counterparts in the cement matrix - is an important immobilisation process in HCP. However, it is not a priori known what proportion of each elemental inventory is available for isotopic exchange. Wet chemistry studies with Cs and Sr show that the total inventory of these elements is reversibly bound and that their partitioning between HCP and pore water can be modelled using the distribution values deduced from studies of the corresponding tracers ( 137 Cs and 85 Sr). This finding corroborates the relevance of isotopic exchange in cementitious systems. Wet chemistry investigations need to be complemented by spectroscopic techniques, e.g., XAFS, in order to gain a mechanistic understanding of the chemical processes by which waste ions become immobilised in cement-based matrices. XAFS can be used to obtain information at the atomic/molecular level, i.e., the type, number and distance of neighbouring atoms. XAFS studies on cementitious systems are still rather rare, and therefore information on the potential and limitations of this technique is sparse. Mechanistic aspects of the immobilisation processes are discussed for some safety-relevant radionuclides (e.g. Ni and Sr) using the

  5. In Situ Raman Spectroscopic Study of Gypsum (CaSO4·2H2O) and Epsomite (MgSO4·7H2O) Dehydration Utilizing an Ultrasonic Levitator.

    Science.gov (United States)

    Brotton, Stephen J; Kaiser, Ralf I

    2013-02-21

    We present an original apparatus combining an acoustic levitator and a pressure-compatible process chamber. To characterize in situ the chemical and physical modifications of a levitated, single particle while heated to well-defined temperatures using a carbon dioxide laser, the chamber is interfaced to a Raman spectroscopic probe. As a proof-of-concept study, by gradually increasing the heating temperature, we observed the variations in the Raman spectra as 150 μg of crystals of gypsum and epsomite were dehydrated in anhydrous nitrogen gas. We display spectra showing the decreasing intensities of the ν1 symmetric and ν3 asymmetric stretching modes of water with time and the simultaneous shift of the ν1(SO4(2-)) symmetric stretch mode to higher wavenumbers. Our results demonstrate that the new apparatus is well suited to study the dehydration of levitated species such as minerals and offers potential advantages compared with previous experiments on bulk samples.

  6. Investigations of different doping concentration of phosphorus and boron into silicon substrate on the variable temperature Raman characteristics

    Science.gov (United States)

    Li, Xiaoli; Ding, Kai; Liu, Jian; Gao, Junxuan; Zhang, Weifeng

    2018-01-01

    Different doped silicon substrates have different device applications and have been used to fabricate solar panels and large scale integrated circuits. The thermal transport in silicon substrates are dominated by lattice vibrations, doping type, and doping concentration. In this paper, a variable-temperature Raman spectroscopic system is applied to record the frequency and linewidth changes of the silicon peak at 520 cm-1 in five chips of silicon substrate with different doping concentration of phosphorus and boron at the 83K to 1473K temperature range. The doping has better heat sensitive to temperature on the frequency shift over the low temperature range from 83K to 300K but on FWHM in high temperature range from 300K to 1473K. The results will be helpful for fundamental study and practical applications of silicon substrates.

  7. Electrochemical and in-situ Surface-Enhanced Raman Spectroscopic (SERS) study of passive films formed on low-carbon steel in highly alkaline environments

    Science.gov (United States)

    Mancio, Mauricio

    In reinforced concrete, a passive layer forms because of the alkaline conditions in the pores of the cement paste, where large concentrations of hydroxides create a solution with pH typically between 12 and 14. The corrosion resistance of the material depends on the characteristics and integrity of the passive film; however, currently very limited information is available about the passive films formed on carbon steel under such conditions. This work presents an electrochemical and in-situ Surface-Enhanced Raman Spectroscopic (SERS) study of passive films formed on low-carbon steel in highly alkaline environments. More specifically, the study focuses on the characterization of the films formed on ASTM A36 steel reinforcing bar exposed to aqueous solutions that aim to reproduce the chemistry of the environment typically found within the cement paste. Electrochemical techniques such as cyclic potentiodynamic polarization curves, galvanostatic cathodic polarization and linear polarization resistance were employed, in addition to in-situ Surface Enhanced Raman Spectroscopy (SERS). The experimental setup was built in a way that SERS experiments could be performed simultaneously with potentiodynamic polarization curves, enabling a detailed analysis of the formation and reduction of the surface films as a function of applied potential. Three solutions with different pH levels were used for the polarization and SERS experiments, namely 0.55M KOH + 0.16M NaOH ([OH-]=0.71), 0.08M KOH + 0.02M NaOH ([OH-]=0.10) and 0.008M KOH + 0.002M NaOH ([OH-]=0.01). Additional NaOH solutions in which the pH was varied from 13 to 9 and the ionic strength from 10 -5 to 10-1 were prepared for a pilot study using linear polarization resistance. Results show that the features observed in the cyclic potentiodynamic polarization curves correlated well with the potential arrests observed in the GCP plots as well as with the changes observed in the SERS spectra, providing valuable information about

  8. Spectroscopic Investigations and DFT Calculations on 3-(Diacetylamino-2-ethyl-3H-quinazolin-4-one

    Directory of Open Access Journals (Sweden)

    Yusuf Sert

    2016-01-01

    Full Text Available The theoretical and experimental vibrational frequencies of 3-(diacetylamino-2-ethyl-3H-quinazolin-4-one (2 were investigated. The experimental Laser-Raman spectrum (4000–100 cm−1 and FT-IR spectrum (4000–400 cm−1 of the newly synthesized compound were recorded in the solid phase. Both the theoretical vibrational frequencies and the optimized geometric parameters such as bond lengths and bond angles have for the first time been calculated using density functional theory (DFT/B3LYP and DFT/M06-2X quantum chemical methods with the 6-311++G(d,p basis set using Gaussian 03 software. The vibrational frequencies were assigned with the help of potential energy distribution (PED analysis using VEDA 4 software. The calculated vibrational frequencies and the optimized geometric parameters were found to be in good agreement with the corresponding reported experimental data. Also, the energies of the lowest unoccupied molecular orbital (LUMO, highest occupied molecular orbital (HOMO, and other related molecular energies for 3-(diacetylamino-2-ethyl-3H-quinazolin-4-one (2 have been investigated using the same computational methods.

  9. Development of laser Raman and x-ray photoelectron spectroscopic parameters as an additional thermal maturity indicator to the conodont alteration index

    International Nuclear Information System (INIS)

    Marshall, C.P.; Wilson, M.A.

    1999-01-01

    Full text: Laser Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) was applied in an attempt to quantify and elucidate the chemical transformations of the conodont alteration index (CAI) in artificially matured conodonts. Coniform elements of the genus Drepanodus from the Ordovician Emanuel Formation and pectiniform elements of the genus Polygnathus from the Devonian Napier Formation, both from the Canning Basin were used in this investigation. Samples where specifically chosen to study the effects of genus, element morphology, geological age, lithology and depositional environment upon the CAI. The first order Raman spectra (900-1800 cm-1) of both sets of conodonts show three bands. These are assigned to apatite at 965 cm-1, D band (defects present in the structural units and disorder) at 1345 cm-1 and the G band (carbon-carbon in plane stretching vibration or structural ordered carbon) at 1600 cm-1. The Raman spectra recorded for both sample sets, CAI range of 1-7 are characteristic of poorly/ highly disordered carbon within the conodont organic matter. Further more, the D band becomes progressively narrower and more intense the higher the thermal treatment. The G band becomes narrower until CAI 4 and after that has no systematic change apart from the intensity decreasing with temperature. The most noteworthy spectral characteristic in relation to thermal maturity is the clearly defined linear trend of decreasing D band line-width with increasing rank. The carbon 1s photoelectron regions acquired from both sample sets contain three peaks. These peaks are assigned to carbon bonded to sp3 and sp2 hybridized carbon (284.7 eV), alcohol (287.2 eV) and carboxyl (288.3 eV) functional groups. With increasing thermal treatment all the carbon constituents show a linear decrease in abundance. The poorly/ highly disordered carbon shows no progressive ordering with increasing thermal treatment. This is also in agreement with the XPS results, in which the aliphatic

  10. Micro-raman and tip-enhanced raman spectroscopy of carbon allotropes

    NARCIS (Netherlands)

    Hoffmann, G.G.; With, de G.; Loos, J.

    2008-01-01

    Raman spectroscopic data are obtained on various carbon allotropes like diamond, amorphous carbon, graphite, graphene and single wall carbon nanotubes by micro-Raman spectroscopy, tip-enhanced Raman spectroscopy and tip-enhanced Raman spectroscopy imaging, and the potentials of these techniques for

  11. Molecular structure, vibrational analysis (IR and Raman) and quantum chemical investigations of 1-aminoisoquinoline

    Science.gov (United States)

    Sivaprakash, S.; Prakash, S.; Mohan, S.; Jose, Sujin P.

    2017-12-01

    Quantum chemical calculations of energy and geometrical parameters of 1-aminoisoquinoline [1-AIQ] were carried out by using DFT/B3LYP method using 6-311G (d,p), 6-311G++(d,p) and cc-pVTZ basis sets. The vibrational wavenumbers were computed for the energetically most stable, optimized geometry. The vibrational assignments were performed on the basis of potential energy distribution (PED) using VEDA program. The NBO analysis was done to investigate the intra molecular charge transfer of the molecule. The frontier molecular orbital (FMO) analysis was carried out and the chemical reactivity descriptors of the molecule were studied. The Mulliken charge analysis, molecular electrostatic potential (MEP), HOMO-LUMO energy gap and the related properties were also investigated at B3LYP level. The absorption spectrum of the molecule was studied from UV-Visible analysis by using time-dependent density functional theory (TD-DFT). Fourier Transform Infrared spectrum (FT-IR) and Raman spectrum of 1-AIQ compound were analyzed and recorded in the range 4000-400 cm-1 and 3500-100 cm-1 respectively. The experimentally determined wavenumbers were compared with those calculated theoretically and they complement each other.

  12. Preliminary investigation of an atmospheric microplasma using Raman and Thomson laser scattering

    Science.gov (United States)

    Sommers, Bradley; Adams, Steven

    2014-10-01

    A triple grating spectrometer system has been coupled with an ultraviolet laser at 266 nm for the purpose of investigating Rayleigh, Raman, and Thomson scattering within atmospheric plasma sources. Such laser interactions present a non-invasive diagnostic to investigate small scale atmospheric plasma sources, which have recently garnered interest for applications in remote optical sensing, materials processing, and environmental decontamination. In this work, the laser scatter and temperature relationship were calibrated with a heated nitrogen cell held at atmospheric pressure while subsequent scattering measurements were made in atmospheric discharges composed of nitrogen and air. An adjustable electrode configuration and dc circuit were assembled to produce a microdischarge operating in normal glow mode, thus providing a non-thermal plasma in which the translational, rotational, vibrational and electron temperatures are not in equilibrium. Preliminary results include measurements of these temperatures, which were calculated by fitting simulated scattering spectra to the experimental data obtained using the triple grating spectrometer. Measured temperatures were also compared with those obtained using standard optical emission spectroscopy methods. Special thanks to the NRC Research Associateship Program.

  13. Raman, SEM-EDS and XRPD investigations on pre-Columbian Central America "estucado" pottery

    Science.gov (United States)

    Casanova Municchia, Annalaura; Micheli, Mario; Ricci, Maria Antonietta; Toledo, Michelle; Bellatreccia, Fabio; Lo Mastro, Sergio; Sodo, Armida

    2016-03-01

    Seventeen different colored fragments from six selected pre-Columbian estucado ceramics from El Salvador have been investigated by Raman spectroscopy, scanning electron microscope coupled to an energy dispersive spectrometer (SEM/EDS) and X-ray powder diffraction (XRPD). The peculiarity of this kind of ceramics consist of the unusual presence of a white engobe, traditionally termed stucco, between the ceramic body and the decoration elements, hence the name estucado ceramics. The aim of this work was to study the unusual manufacturing technique and to identify the chemical composition of the engobe and of the pigment palette. The results showed that the stucco layer is made of clay (kaolinite) with traces of titanium oxide (anatase). Remarkably, this is the same composition of the white pigments used for the decoration layer, thus excluding an early use of natural titanium oxide as a white pigment in the estucado productions as suggested in previous investigations. Moreover, the presence of kaolinite and anatase both in the stucco and in the decoration layer suggests a cold-working or low temperature technique. The red, yellow and green decorations were realized by the use of natural ochre, while in all the blue and gray decorations Maya blue pigment was identified. Finally, an amorphous carbon pigment of vegetal origin and manganese oxide were used to obtain black pigments.

  14. Spatially resolved investigation of the oil composition in single intact hyphae of Mortierella spp. with micro-Raman spectroscopy.

    Science.gov (United States)

    Münchberg, Ute; Wagner, Lysett; Spielberg, Eike T; Voigt, Kerstin; Rösch, Petra; Popp, Jürgen

    2013-02-01

    Zygomycetes are well known for their ability to produce various secondary metabolites. Fungi of the genus Mortierella can accumulate highly unsaturated lipids in large amounts as lipid droplets. However, no information about the spatial distribution or homogeneity of the oil inside the fungi is obtainable to date due to the invasive and destructive analytical techniques applied so far. Raman spectroscopy has been demonstrated to be well suited to investigate biological samples on a micrometre scale. It also has been shown that the degree of unsaturation of lipids can be determined from Raman spectra. We applied micro-Raman spectroscopy to investigate the spatial distribution and composition of lipid vesicles inside intact hyphae. For Mortierella alpina and Mortierella elongata distinct differences in the degree of unsaturation and even the impact of growth conditions are determined from the Raman spectra. In both species we found that the fatty acid saturation in the vesicles is highly variable in the first 600 μm of the growing hyphal tip and fluctuates towards a constant composition and saturation ratio in all of the remaining mycelium. Our approach facilitates in vivo monitoring of the lipid production and allows us to investigate the impact of cultivation parameters on the oil composition directly in the growing hyphae without the need for extensive extraction procedures. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. In situ spectroscopic investigation of the cobalt-catalyzed oxidation of lignin model compounds in ionic liquids

    NARCIS (Netherlands)

    Zakzeski, J.|info:eu-repo/dai/nl/326160256; Bruijnincx, P.C.A.|info:eu-repo/dai/nl/33799529X; Weckhuysen, B.M.|info:eu-repo/dai/nl/285484397

    2011-01-01

    The cobalt-catalyzed oxidation of lignin and lignin model compounds using molecular oxygen in ionic liquids proceeds readily under mild conditions, but mechanistic insight and evidence for the species involved in the catalytic cycle is lacking. In this study, a spectroscopic investigation of the

  16. A deuterium and carbon nuclear magnetic resonance spectroscopic investigation of blood flow and carbohydrate metabolism

    International Nuclear Information System (INIS)

    Bosch, C.S.E.

    1988-01-01

    The purpose of this study is the development and application of nuclear magnetic resonance (NMR) spectroscopic techniques for this study of whole tissue metabolism, tissue perfusion and blood flow. The feasibility of spin imaging deuterium-enriched tissue water is demonstrated in cat brain in vivo and in situ. The potential application of D 2 O administration to deuterium-flow-imaging is considered. NMR investigations of hepatic carbohydrate metabolism were performed in rat liver in vivo and in situ. A coaxial, double-surface-coil, double-resonance probe was developed for carbon detection while decoupling neighboring proton scalar interactions ( 13 C-[ 1 H]) in hepatic tissue within the living animal. Hormonal and substrate regulation of hepatic glucose and glycogen metabolism was investigated by monitoring the metabolic fate of an administered c-dose of [1- 13 C]glucose. Label flux was directed primarily into newly-synthesized 13 C-labeled glycogen. A multiple resonance ( 1 H, 13 C, 31 P) liver perfusion probe was designed for complimentary carbohydrate metabolic studies in rat liver in vitro. A description of the 13 C-[ 1 H]/ 31 P NMR perfusion probe is given. The surgical technique used for liver excision and peripheral life-support apparatus required to maintain hepatic function are also detailed

  17. Spectroscopic investigation of zinc tellurite glasses doped with Yb3 + and Er3 + ions

    Science.gov (United States)

    Bilir, Gökhan; Kaya, Ayfer; Cinkaya, Hatun; Eryürek, Gönül

    2016-08-01

    This paper presents a detailed spectroscopic investigation of zinc tellurite glasses with the compositions (0.80 - x - y) TeO2 + (0.20) ZnO + xEr2O3 + yYb2O3 (x = 0, y = 0; x = 0.004, y = 0; x = 0, y = 0.05 and x = 0.004, y = 0.05 per moles). The samples were synthesized by the conventional melt quenching method. The optical absorption and emission measurements were conducted at room temperature to determine the spectral properties of lanthanides doped zinc tellurite glasses and, to study the energy transfer processes between dopant lanthanide ions. The band gap energies for both direct and indirect possible transitions and the Urbach energies were measured from the absorption spectra. The absorption spectra of the samples were analyzed by using the Judd-Ofelt approach. The effect of the ytterbium ions on the emission properties of erbium ions was investigated and the energy transfer processes between dopant ions were studied by measuring the up-conversion emission properties of the materials. The color quality parameters of obtained visible up-conversion emission were also determined as well as possibility of using the Er3 + glasses as erbium doped fiber amplifiers at 1.55 μm in infrared emission region.

  18. Spectroscopic investigation of zinc tellurite glasses doped with Yb(3+) and Er(3+) ions.

    Science.gov (United States)

    Bilir, Gökhan; Kaya, Ayfer; Cinkaya, Hatun; Eryürek, Gönül

    2016-08-05

    This paper presents a detailed spectroscopic investigation of zinc tellurite glasses with the compositions (0.80-x-y) TeO2+(0.20) ZnO+xEr2O3+yYb2O3 (x=0, y=0; x=0.004, y=0; x=0, y=0.05 and x=0.004, y=0.05 per moles). The samples were synthesized by the conventional melt quenching method. The optical absorption and emission measurements were conducted at room temperature to determine the spectral properties of lanthanides doped zinc tellurite glasses and, to study the energy transfer processes between dopant lanthanide ions. The band gap energies for both direct and indirect possible transitions and the Urbach energies were measured from the absorption spectra. The absorption spectra of the samples were analyzed by using the Judd-Ofelt approach. The effect of the ytterbium ions on the emission properties of erbium ions was investigated and the energy transfer processes between dopant ions were studied by measuring the up-conversion emission properties of the materials. The color quality parameters of obtained visible up-conversion emission were also determined as well as possibility of using the Er(3+) glasses as erbium doped fiber amplifiers at 1.55μm in infrared emission region. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. In-situ investigation of the calcination process of mixed oxide xerogels with Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Panitz, J C [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    The controlled calcination of materials derived by sol-gel reactions is important for the evolution of the final structure. Raman spectroscopy is an ideal tool for the identification of surface species under in-situ conditions, as demonstrated in the following for the example of a molybdenum oxide-silica xerogel. Raman spectra of this particular sample were recorded at temperatures as high as 1173 K, and compared with those of a reference material.(author) 3 figs., 4 refs.

  20. Vibrational spectroscopic and dielectric properties investigations of phase transitions in KMgPO4 compound

    Science.gov (United States)

    Miladi, L.; Oueslati, A.; Guidara, K.

    2017-11-01

    The potassium orthophosphate KMgPO4 with a β-tridymite structure was synthesized via solid-state reaction. X-ray diffraction study confirms the formation of a single phase material which crystallizes at room temperature in monoclinic system. This compound has been investigated by vibrational spectroscopy in the temperature range573-723 K. Thermal analysis shows that this composition undergoes two phase transitions at T1=633Kand T2=693 K.The evolution of Raman line ν and half -width Δν versus temperature introduces huge changes which are associated with the phase transitions originating from the reorientation of the PO4 tetrahedron. Besides, an analysis of the dielectric constants ε‧ and ε″versus temperature at several frequencies shows a distribution of relaxation times. This relaxation is probably due to the change in dynamical state of the K+ cation. The ac conductivity behavior can be understood in terms of the motions of K+ cations along the tunnels which are formed by six-membered rings of MgO4 and PO4 tetrahedron linked by common vertices. The activation energies values obtained from the thermal evolution of the conductivity are: Ea1=0.52 eV (T693 K).

  1. Computational NMR, IR/RAMAN calculations in sodium pravastatin: Investigation of the Self-Assembled Nanostructure of Pravastatin-LDH (Layered Double Hydroxides) Systems

    Science.gov (United States)

    Petersen, Philippe; Cunha, Vanessa; Gonçalves, Marcos; Petrilli, Helena; Constantino, Vera; Instituto de Física, Departamento de Física de Materiais e Mecânica Team; Instituto de Química, Departamento de Química Fundamental Team

    2013-03-01

    Layered double hydroxides (LDH) can be used as nanocontainers for immobilization of Pravastatin, in order to obtain suitable drug carriers. The material's structure and spectroscopic properties were analyzed by NMR, IR/RAMAN and supported by theoretical calculations. Density Functional Theory (DFT) calculations were performed using the Gaussian03 package. The geometry optimizations were performed considering the single crystal X-ray diffraction data of tert-octylamonium salt of Pravastatin. Tetramethylsilane (TMS), obtained with the same basis set, was used as reference for calculating the chemical shift of 13C. A scaling factor was used to compare theoretical and experimental harmonic vibrational frequencies. Through the NMR and IR/RAMAN spectra, we were able to make precise assignments of the NMR and IR/RAMAN of Sodium Pravastatin. We acknowledge support from CAPES, INEO and CNPQ.

  2. Electrochemical and Spectroscopic Study of Mononuclear Ruthenium Water Oxidation Catalysts: A Combined Experimental and Theoretical Investigation

    KAUST Repository

    de Ruiter, J. M.; Purchase, R. L.; Monti, A.; van der Ham, C. J. M.; Gullo, M. P.; Joya, K. S.; D'Angelantonio, M.; Barbieri, A.; Hetterscheid, D. G. H.; de Groot, H. J. M.; Buda, F.

    2016-01-01

    derivatives). The proposed catalytic cycle and intermediates are examined using density functional theory (DFT), radiation chemistry, spectroscopic techniques, and electrochemistry to establish the water oxidation mechanism. The stability of the catalyst

  3. Investigation of Chinese archaic jade by PIXE and μRaman spectrometry

    International Nuclear Information System (INIS)

    Chen, T.H.; Calligaro, T.; Pages-Camagna, S.; Menu, M.

    2004-01-01

    External-beam particle-induced X-ray emission (PIXE) and μRaman spectrometry were used for elemental and structural studies of Chinese archaic nephrite jades of the Guimet Asian Museum in Paris in a non-destructive way. Nephrite is a variety of tremolite-actinolite of the amphibole group, with variable iron and magnesium contents. In the present work, in addition to identification of materials, the cation distribution in nephrite was investigated. Cation order-disorder is related to thermodynamic properties of minerals, and hence associated with geological conditions of the mineral formation. Besides, it plays an important role in the mechanism of coloration. So far, little work has been done on the cation distribution in nephrite. We thus initiated this research expecting to answer open questions concerning art and archaeological issues such as jade provenance and colour. The OH stretching vibration band of nephrite, depending on the electronegativity of the bonded cations, presents a fine structure. The study of this fine structure, together with the total cation content obtained by PIXE, allows estimation of the cation distribution in nephrite. In this study, six jade artefacts, dated from the Neolithic period to the Han dynasty (about 3000 BC to 220 AD), with diverse colours including white, yellow-green, green, dark green and black, were analysed. The data obtained permits establishing a geological database for determination of nephrite provenance and explaining the correlation between colour and cation distribution. (orig.)

  4. Spectroscopic investigations on Pr3+ ions doped lead telluro-borate glasses for photonic applications

    Science.gov (United States)

    Suthanthirakumar, P.; Mariyappan, M.; Marimuthu, K.

    2018-04-01

    A new series of Lead telluro-borate glasses doped with different concentrations of Pr3+ ions (xPLTB) were prepared by melt quenching technique and their structural and spectroscopic properties were investigated by recording XRD, FTIR, optical absorption and luminescence spectral measurements. XRD measurements confirm the amorphous nature and the FTIR spectra reveal the presence of different vibrational modes of borate and tellurite networks in the prepared glasses. The bonding parameter values (δ) obtained from the absorption band positions indicates that the bonding between Pr3+ ions and their surrounding ligands is of ionic in nature. The optical band gap (Eopt) corresponding to the direct and indirect allowed transitions were determined with the framework of tauc's plot. From the luminescence spectra, important radiative parameters such as stimulated emission cross-section (σPE) , branching ratios (βR) and radiative lifetime (τR) were calculated for the dominant emission transition 3P0→3H4 (blue) in order to suggest the suitability of the studied glasses for suitable photonic applications.

  5. FT-IR, NMR spectroscopic and quantum mechanical investigations of two ferrocene derivatives

    Directory of Open Access Journals (Sweden)

    Ö. Alver

    2017-07-01

    Full Text Available New ferrocene derivatives as N-(3-piperidin-1-ylpropylferrocenamide (Fc-3ppa and N-(pyridine-3-ylmethylferrocenamide (Fc-3pica and structural investigations were carried out with 1H, 13C, DEPT 45 or 135, HETCOR, COSY NMR and FT-IR spectroscopic techniques. Characterization of Fc-3ppa (FeC19H26N2O and Fc-3pica (FeC17H16N2O was also supported by density functional theory (DFT used by B3LYP functional and 6-31G(d or 6-311++G(d,p basis sets. From the combination of all the results, it can be clearly seen that syntheses of Fc-3ppa and Fc-3pica have been successfully achieved. Theoretical values are successfully compared against experimental data and B3LYP method is able to provide satisfactory results for predicting NMR properties and vibrational frequencies of the synthesized ferrocene based systems.

  6. Electrochemical and Spectroscopic Study of Mononuclear Ruthenium Water Oxidation Catalysts: A Combined Experimental and Theoretical Investigation

    KAUST Repository

    de Ruiter, J. M.

    2016-09-20

    One of the key challenges in designing light-driven artificial photosynthesis devices is the optimization of the catalytic water oxidation process. For this optimization it is crucial to establish the catalytic mechanism and the intermediates of the catalytic cycle, yet a full description is often difficult to obtain using only experimental data. Here we consider a series of mononuclear ruthenium water oxidation catalysts of the form [Ru(cy)(L)(H2O)](2+) (cy = p-cymene, L = 2,2\\'-bipyridine and its derivatives). The proposed catalytic cycle and intermediates are examined using density functional theory (DFT), radiation chemistry, spectroscopic techniques, and electrochemistry to establish the water oxidation mechanism. The stability of the catalyst is investigated using online electrochemical mass spectrometry (OLEMS). The comparison between the calculated absorption spectra of the proposed intermediates with experimental spectra, as well as free energy calculations with electrochemical data, provides strong evidence for the proposed pathway: a water oxidation catalytic cycle involving four proton-coupled electron transfer (PCET) steps. The thermodynamic bottleneck is identified as the third PCET step, which involves O-O bond formation. The good agreement between the optical and thermodynamic data and DFT predictions further confirms the general applicability of this methodology as a powerful tool in the characterization of water oxidation catalysts and for the interpretation of experimental observables.

  7. Infrared Spectroscopic Study For Structural Investigation Of Lithium Lead Silicate Glasses

    International Nuclear Information System (INIS)

    Ahlawat, Navneet; Aghamkar, Praveen; Ahlawat, Neetu; Agarwal, Ashish; Monica

    2011-01-01

    Lithium lead silicate glasses with composition 30Li 2 O·(70-x)PbO·xSiO 2 (where, x = 10, 20, 30, 40, 50 mol %)(LPS glasses) were prepared by normal melt quench technique at 1373 K for half an hour in air to understand their structure. Compositional dependence of density, molar volume and glass transition temperature of these glasses indicates more compactness of the glass structure with increasing SiO 2 content. Fourier transform infrared (FTIR) spectroscopic data obtained for these glasses was used to investigate the changes induced in the local structure of samples as the ratio between PbO and SiO 2 content changes from 6.0 to 0.4. The observed absorption band around 450-510 cm -1 in IR spectra of these glasses indicates the presence of network forming PbO 4 tetrahedral units in glass structure. The increase in intensity with increasing SiO 2 content (upto x = 30 mol %) suggests superposition of Pb-O and Si-O bond vibrations in absorption band around 450-510 cm -1 . The values of optical basicity in these glasses were found to be dependent directly on PbO/SiO 2 ratio.

  8. Infrared and Raman spectroscopic characterizations on new Fe sulphoarsenate hilarionite (Fe2(III)(SO4)(AsO4)(OH)·6H2O): Implications for arsenic mineralogy in supergene environment of mine area

    Science.gov (United States)

    Liu, Jing; He, LiLe; Dong, Faqin; Frost, Ray L.

    2017-01-01

    Hilarionite (Fe2 (SO4)(AsO4)(OH)·6H2O) is a new Fe sulphoarsenates mineral, which recently is found in the famous Lavrion ore district, Atliki Prefecture, Greece. The spectroscopic study of hilarionite enriches the data of arsenic mineralogy in supergene environment of a mine area. The infrared and Raman means are used to characterize the molecular structure of this mineral. The IR bands at 875 and 905 cm- 1 are assigned to the antisymmetric stretching vibrations of AsO43 -. The IR bands at 1021, 1086 and 1136 cm- 1 correspond to the possible antisymmetric and symmetric stretching vibrations of SO42 -. The Raman bands at 807, 843 and 875 cm- 1 clearly show that arsenate components in the mineral structure, which are assigned to the symmetric stretching vibrations (ν1) of AsO43 - (807 and 843 cm- 1) and the antisymmetric vibration (ν3) (875 cm- 1). IR bands provide more sulfate information than Raman, which can be used as the basis to distinguish hilarionite from kaňkite. The powder XRD data shows that hilarionite has obvious differences with the mineral structure of kaňkite. The thermoanalysis and SEM-EDX results show that hilarionite has more sulfate than arsenate.

  9. An Investigation on Micro-Raman Spectra and Wavelet Data Analysis for Pemphigus Vulgaris Follow-up Monitoring.

    Science.gov (United States)

    Camerlingo, Carlo; Zenone, Flora; Perna, Giuseppe; Capozzi, Vito; Cirillo, Nicola; Gaeta, Giovanni Maria; Lepore, Maria

    2008-06-01

    A wavelet multi-component decomposition algorithm has been used for data analysis of micro-Raman spectra of blood serum samples from patients affected by pemphigus vulgaris at different stages. Pemphigus is a chronic, autoimmune, blistering disease of the skin and mucous membranes with a potentially fatal outcome. Spectra were measured by means of a Raman confocal microspectrometer apparatus using the 632.8 nm line of a He-Ne laser source. A discrete wavelet transform decomposition method has been applied to the recorded Raman spectra in order to overcome problems related to low-level signals and the presence of noise and background components due to light scattering and fluorescence. This numerical data treatment can automatically extract quantitative information from the Raman spectra and makes more reliable the data comparison. Even if an exhaustive investigation has not been done in this work, the feasibility of the follow-up monitoring of pemphigus vulgaris pathology has been clearly proved with useful implications for the clinical applications.

  10. An Investigation on Micro-Raman Spectra and Wavelet Data Analysis for Pemphigus Vulgaris Follow-up Monitoring.

    Directory of Open Access Journals (Sweden)

    Maria Lepore

    2008-06-01

    Full Text Available A wavelet multi-component decomposition algorithm has been used for data analysis of micro-Raman spectra of blood serum samples from patients affected by pemphigus vulgaris at different stages. Pemphigus is a chronic, autoimmune, blistering disease of the skin and mucous membranes with a potentially fatal outcome. Spectra were measured by means of a Raman confocal microspectrometer apparatus using the 632.8 nm line of a He-Ne laser source. A discrete wavelet transform decomposition method has been applied to the recorded Raman spectra in order to overcome problems related to low-level signals and the presence of noise and background components due to light scattering and fluorescence. This numerical data treatment can automatically extract quantitative information from the Raman spectra and makes more reliable the data comparison. Even if an exhaustive investigation has not been done in this work, the feasibility of the follow-up monitoring of pemphigus vulgaris pathology has been clearly proved with useful implications for the clinical applications.

  11. An FT-Raman, FT-IR, and Quantum Chemical Investigation of Stanozolol and Oxandrolone

    Directory of Open Access Journals (Sweden)

    Tibebe Lemma

    2017-12-01

    Full Text Available We have studied the Fourier Transform Infrared (FT-IR and the Fourier transform Raman (FT-Raman spectra of stanozolol and oxandrolone, and we have performed quantum chemical calculations based on the density functional theory (DFT with a B3LYP/6-31G (d, p level of theory. The FT-IR and FT-Raman spectra were collected in a solid phase. The consistency between the calculated and experimental FT-IR and FT-Raman data indicates that the B3LYP/6-31G (d, p can generate reliable geometry and related properties of the title compounds. Selected experimental bands were assigned and characterized on the basis of the scaled theoretical wavenumbers by their total energy distribution. The good agreement between the experimental and theoretical spectra allowed positive assignment of the observed vibrational absorption bands. Finally, the calculation results were applied to simulate the Raman and IR spectra of the title compounds, which show agreement with the observed spectra.

  12. Spectroscopic and TDDFT investigation on highly selective fluorogenic chemosensor and construction of molecular logic gates

    Energy Technology Data Exchange (ETDEWEB)

    Basheer, Sabeel M [Department of Chemistry, National Institute of Technology, Tiruchirappalli 620 015 (India); Kumar, Saravana Loganathan Ashok [Department of Chemistry, GRT Institute of Engineering Technology, Tiruttani (India); Kumar, Moorthy Saravana [Research and PG Department of Chemistry, Saraswathi Narayanan College, Madurai 625022 (India); Sreekanth, Anandaram, E-mail: sreekanth@nitt.edu [Department of Chemistry, National Institute of Technology, Tiruchirappalli 620 015 (India)

    2017-03-01

    1,5-Bis(2-fluorene)thiocarbohydrazone (FBTC) was designed and synthesized for selective sensing of fluoride and copper ions. The binding constants of FBTC towards fluoride and copper ions have been calculated using the Benesi-Hildebrand equation, and FBTC has more binding affinity towards copper ion than fluoride ion. The {sup 1}H NMR and {sup 13}C NMR titration studies strongly support the deprotonation was taken from the N–H protons followed by the formation of hydrogen bond via N–H{sup …}F. To understand the fluoride ion sensing mechanism, theoretical investigation had been carried out using the density functional theory and time-dependent density functional theory. The theoretical data well reproduced the experimental results. The deprotonation process has a moderate transition barrier (481.55 kcal/mol). The calculated ΔE and ΔG values (− 253.92 and − 192.41 kcal/mol respectively) suggest the feasibility of sensing process. The potential energy curves give the optimized structures of FBTC-F complex in the ground state and excited state, which states the proton transition occurs at the excited state. The excited state proton transition mechanism was further confirmed with natural bond orbital analysis. The reversibility of the sensor was monitored by the alternate addition of F{sup −} and Cu{sup 2+} ions, which was explained with “Read-Erase-Write-Read” behaviour. The multi-ion detection of sensor used to construct the molecular logic gate, such as AND, OR, NOR and INHIBITION logic gates. - Highlight: • Synthesis and characterised the thiosemicarbohydrazone derivative • Experimental evolution of selective fluoride and copper sensing via both colorimetric and spectroscopic studies • The proposed sensing mechanism of fluoride and copper ion were further confirmed with DFT and TD-DFT investigation • Receptor was turned as molecular switches and molecular logic gates.

  13. Spectroscopic investigations of novel pharmaceuticals: Stability and resonant interaction with laser beam

    Science.gov (United States)

    Smarandache, Adriana; Boni, Mihai; Andrei, Ionut Relu; Handzlik, Jadwiga; Kiec-Kononowicz, Katarzyna; Staicu, Angela; Pascu, Mihail-Lucian

    2017-09-01

    This paper presents data about photophysics of two novel thio-hydantoins that exhibit promising pharmaceutical properties in multidrug resistance control. Time stability studies are necessary to establish the proper use of these compounds in different applications. As for their administration as drugs, it is imperative to know their shelf life, as well as storage conditions. At the same time, laser induced modified properties of the two new compounds are valuable to further investigate their specific interactions with other materials, including biological targets. The two new thio-hydantoins under generic names SZ-2 and SZ-7 were prepared as solutions in dimethyl sulfoxide at different concentrations, as well as in deionised water. For the stability assay they were kept in various light/temperature conditions up to 60 days. The stability was estimates based on UV-vis absorption measurements. The samples in bulk shape were exposed different time intervals to laser radiation emitted at 266 nm as the fourth harmonic of a Nd:YAG laser. The resonant interaction of the studied compounds with laser beams was analysed through spectroscopic methods UV-vis and FTIR absorption, as well as laser induced fluorescence spectroscopy. As for stability assay, only solutions kept in dark at 4 °C have preserved the absorption characteristics, considering the cumulated measuring errors, less than one week. The vibrational changes that occur in their FTIR and modified fluorescence spectra upon laser beam exposure are also discussed. A result of the experimental analysis is that modifications are induced in molecular structures of the investigated compounds by resonant interaction with laser radiation. This fact evidences that the molecules are photoreactive and their characteristics might be shaped through controlled laser radiation exposure using appropriate protocols. This conclusion opens many opportunities both in the biomedical field, but also in other industrial activities

  14. Spectroscopic investigation of Bovine Liver Catalase interactions with a novel phen-imidazole derivative of platinum.

    Science.gov (United States)

    Ghobadi, Roohollah; Divsalar, Adeleh; Harifi-Mood, Ali Reza; Saboury, Ali Akbar

    2018-02-01

    Successful clinical experience of using cisplatin and its derivatives in cancer therapy has encouraged scientists to synthesize new metal complexes with the aim of interacting with special targets such as proteins In this regard, biological effects of [Pt(FIP)(Phen)](NO 3 ) 2 compound which contains a novel phen-imidazole ligand, FIP, was investigated on bovine liver catalase (BLC) structure and function. Various spectroscopic methods such as UV-visible, fluorescence, and circular dichroism (CD) were applied at two temperatures 25 and 37°C for kinetics and structural studies. As a consequence, the enzymatic activity decreased slightly with increasing the platinum compound's concentration up to 30 μM and then remained constant at near 80% after this concentration. On the other hand, the fluorescence quenching measurements revealed that despite slight changes in activity, catalase experiences notable alterations in three-dimensional environment around the chromophores of the enzyme structure with increasing platinum complex concentration. Moreover, quenching data showed that BLC has two binding sites for Pt complex and hydrogen bonding interactions play a major role in the binding process. Furthermore, CD spectroscopy data showed that Pt(II) complex induces significant decrease in α-helix content of the secondary structure of BLC, but notable increase in random coil proportion accompanying a slight decrease in β-sheet content. All in all, hydrogen bonding interactions which are mainly involved in the binding process of the novel phen-imidazole compound to BLC significantly alter the protein structure but slightly change its function. This might be a promising outcome for chemotherapists and medicinal chemists to investigate in vivo properties of this novel metal complex with significant binding tendency to a macromolecule in the low concentrations without decreasing its intrinsic function.

  15. SEM, EDX and Raman and infrared spectroscopic study of brianyoungite Zn3(CO3,SO4)(OH)4 from Esperanza Mine, Laurion District, Greece

    Science.gov (United States)

    Frost, Ray L.; López, Andrés; Wang, Lina; Scholz, Ricardo; Sampaio, Ney Pinheiro

    2015-10-01

    The mineral brianyoungite, a carbonate-sulphate of zinc, has been studied by scanning electron microscopy (SEM) with chemical analysis using energy dispersive spectroscopy (EDX) and Raman and infrared spectroscopy. Multiple carbonate stretching modes are observed and support the concept of non-equivalent carbonate units in the brianyoungite structure. Intense Raman band at 1056 cm-1 with shoulder band at 1038 cm-1 is assigned to the CO32- ν1 symmetric stretching mode. Two intense Raman bands at 973 and 984 cm-1 are assigned to the symmetric stretching modes of the SO42- anion. The observation of two bands supports the concept of the non-equivalence of sulphate units in the brianyoungite structure. Raman bands at 704 and 736 cm-1 are assigned to the CO32- ν4 bending modes and Raman bands at 507, 528, 609 and 638 cm-1 are assigned to the CO32- ν2 bending modes. Multiple Raman and infrared bands in the OH stretching region are observed, proving the existence of water and hydroxyl units in different molecular environments in the structure of brianyoungite. Vibrational spectroscopy enhances our knowledge of the molecular structure of brianyoungite.

  16. Strain, doping, and disorder effects in GaAs/Ge/Si heterostructures: A Raman spectroscopy investigation

    Science.gov (United States)

    Mlayah, A.; Carles, R.; Leycuras, A.

    1992-01-01

    The present work is devoted to a Raman study of GaAs/Ge/Si heterostructures grown by the vapor-phase epitaxy technique. We first show that the GaAs epilayers are submitted to a biaxial tensile strain. The strain relaxation generates misfit dislocations and thus disorder effects which we analyze in terms of translational invariance loss and Raman selection rules violation. The first-order Raman spectra of annealed samples exhibit an unexpected broadband we identify as due to scattering by a coupled LO phonon-damped plasmon mode. This is corroborated by an accurate line-shape analysis which accounts for the recorded spectra and makes evident the presence of free carriers within the GaAs layers. Their density is estimated from the deduced plasmon frequency and also using a method we have presented in a previous work.

  17. Spectroscopic [FT-IR and FT-Raman] and theoretical [UV-Visible and NMR] analysis on α-Methylstyrene by DFT calculations

    Science.gov (United States)

    Karthikeyan, N.; Joseph Prince, J.; Ramalingam, S.; Periandy, S.

    2015-05-01

    In the present research work, the FT-IR, FT-Raman and 13C and 1H NMR spectra of the α-Methylstyrene were recorded. The observed fundamental frequencies in finger print as well as functional group regions were assigned according to their uniqueness region. The Gaussian computational calculations are carried out by HF and DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results were tabulated. The impact of the presence of vinyl group in phenyl structure of the compound is investigated. The modified vibrational pattern of the molecule associated vinyl group was analyzed. Moreover, 13C NMR and 1H NMR were calculated by using the gauge independent atomic orbital (GIAO) method with B3LYP methods and the 6-311++G(d,p) basis set and their spectra were simulated and the chemical shifts linked to TMS were compared. A study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies were carried out. The kubo gap of the present compound was calculated related to HOMO and LUMO energies which confirm the occurring of charge transformation between the base and ligand. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. The NLO properties related to Polarizability and hyperpolarizability based on the finite-field approach were also discussed.

  18. Prospects for in vivo Raman spectroscopy

    International Nuclear Information System (INIS)

    Hanlon, E.B.; Manoharan, R.; Koo, T.-W.; Shafer, K.E.; Motz, J.T.; Fitzmaurice, M.; Kramer, J.R.; Itzkan, I.; Dasari, R.R.; Feld, M.S.

    2000-01-01

    Raman spectroscopy is a potentially important clinical tool for real-time diagnosis of disease and in situ evaluation of living tissue. The purpose of this article is to review the biological and physical basis of Raman spectroscopy of tissue, to assess the current status of the field and to explore future directions. The principles of Raman spectroscopy and the molecular level information it provides are explained. An overview of the evolution of Raman spectroscopic techniques in biology and medicine, from early investigations using visible laser excitation to present-day technology based on near-infrared laser excitation and charge-coupled device array detection, is presented. State-of-the-art Raman spectrometer systems for research laboratory and clinical settings are described. Modern methods of multivariate spectral analysis for extracting diagnostic, chemical and morphological information are reviewed. Several in-depth applications are presented to illustrate the methods of collecting, processing and analysing data, as well as the range of medical applications under study. Finally, the issues to be addressed in implementing Raman spectroscopy in various clinical applications, as well as some long-term directions for future study, are discussed. (author)

  19. Infrared and Raman investigation of rare-earth phosphate glasses for potential use as radioactive waste forms

    International Nuclear Information System (INIS)

    Morgan, S.H.

    1989-01-01

    This project was designed to investigate the properties of the rare-earth phosphate glass systems CeO 2 -P 2 O 5 and Pr 2 O 3 -P 2 O 5 for potential use as radioactive waste glasses. The glass-forming region and optimum processing parameters of these glass systems were investigated. The structure of the host glasses and glassed loaded with simulated waste elements was investigated using Raman and infrared spectroscopy. Because of the radical differences in the spectra of the molybdenum-loaded glasses, the structure of the MoO 3 -P 2 O 5 glass system was also investigated. 29 refs., 8 figs., 2 tabs

  20. FT-Raman and FT-Infrared investigations of archaeological artefacts from Foeni Neolithic site (Banat, Romania)

    OpenAIRE

    Simona Cîntă Pînzaru; Dana Pop; Loredana Nemeth

    2008-01-01

    An impressive collection of chert artefacts from the Foeni Neolithic archaeological site (Timiş County, Banat region, Romania) is hosted by the Banat Museum in Timişoara. A representative set of seven specimens was non-destructively investigated using FT-Raman and ATR-FT-IR spectroscopy. The research was carried out for checking if these readily-available, non-destructive, fast, and cheap methods, which do not require preliminary sample preparation could provide significant information for ch...

  1. Spectroscopic investigation on europium doped heavy metal borate glasses for red luminescent application

    Energy Technology Data Exchange (ETDEWEB)

    Hegde, Vinod; Wagh, Akshatha; Kamath, Sudha D. [Manipal University, Department of Physics, Manipal Institute of Technology, Manipal (India); Hegde, Hemanth [Manipal University, Department of Chemistry, Manipal Institute of Technology, Manipal (India); Vishwanath, C.S.D. [Sri Venkateswara University, Department of Physics, Tirupati (India)

    2017-05-15

    The present study explores a new borate family glasses based on 10ZnO-5Na{sub 2}O-10Bi{sub 2}O{sub 3}-(75 - x) B{sub 2}O{sub 3}-xEu{sub 2}O{sub 3} (x = 0, 0.1, 0.5, 1, 1.5, 2, 3 mol%) composition, synthesized by rapid melt quench technique. Prepared glasses were subjected to the density and refractive index measurements and their values were used to calculate other physical properties of the glass matrix as a function of Eu{sup 3+} concentration. XRD confirmed amorphous nature of the glasses. FTIR spectra in the absorption mode were recorded in the 400-4000 cm{sup -1} region to identify different functional groups in the glass matrix. Deconvoluted FTIR spectra showed increase in BO{sub 4} units with rise in europium content which confirmed the 'network strengthener' role of europium ions by creating bridging oxygens (BOs). Optical properties were investigated for their luminescence behavior through various spectroscopic techniques such as UV-Vis-NIR absorption, excitation, emission, decay profiles, and color measurements at room temperature. Lasing properties of the glasses like total radiative life time, branching ratio, emission cross section, and optical gain were obtained from the calculated Judd-Ofelt (Ω{sub 2},Ω{sub 4}) intensity parameters. From the measured values of emission, cross sections, branching ratios, life times, strong photoluminescence features, and CIE chromaticity coordinates, 0.5 mol% of Eu{sup 3+} ions doped ZnNaBiB glasses showed optimum performance and are potential candidate for red light generation at 613 nm. (orig.)

  2. Comparative Spectroscopic Investigation of Tm3+:Tellurite Glasses for 2-μm Lasing Applications

    Directory of Open Access Journals (Sweden)

    Huseyin Cankaya

    2018-02-01

    Full Text Available We performed a comparative spectroscopic analysis on three novel Tm3+:tellurite-based glasses with the following compositions Tm2O3:TeO2-ZnO (TeZnTm, Tm2O3:TeO2-Nb2O5 (TeNbTm, and Tm3+:TeO2-K2O-Nb2O5 (TeNbKTm, primarily for 2-μm laser applications. Tellurite glasses were prepared at different doping concentrations in order to investigate the effect of Tm3+ ion concentration as well as host composition on the stimulated emission cross sections and the luminescence quantum efficiencies. By performing Judd–Ofelt analysis, we determined the average radiative lifetimes of the 3H4 level to be 2.55 ± 0.07 ms, 2.76 ± 0.03 ms and 2.57 ± 0.20 ms for the TeZnTm, TeNbTm and TeNbKTm samples, respectively. We clearly observed the effect of the cross-relaxation, which becomes significant at higher Tm2O3 concentrations, leading to the quenching of 1460-nm emission and enhancement of 1860-nm emission. Furthermore, with increasing Tm2O3 concentrations, we observed a decrease in the fluorescence lifetimes as a result of the onset of non-radiative decay. For the 3H4 level, the highest obtained quantum efficiency was 32% for the samples with the lowest Tm2O3 ion concentration. For the 1860-nm emission band, the average emission cross section was determined to measure around 6.33 ± 0.34 × 10−21 cm2, revealing the potential of thulium-doped tellurite gain media for 2-μm laser applications in bulk and fiber configurations.

  3. Spectroscopic Investigations of Highly Charged Tungsten Ions - Atomic Spectroscopy and Fusion Plasma Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Clementson, Joel [Lund Univ. (Sweden)

    2010-05-01

    The spectra of highly charged tungsten ions have been investigated using x-ray and extreme ultraviolet spectroscopy. These heavy ions are of interest in relativistic atomic structure theory, where high-precision wavelength measurements benchmark theoretical approaches, and in magnetic fusion research, where the ions may serve to diagnose high-temperature plasmas. The work details spectroscopic investigations of highly charged tungsten ions measured at the Livermore electron beam ion trap (EBIT) facility. Here, the EBIT-I and SuperEBIT electron beam ion traps have been employed to create, trap, and excite tungsten ions of M- and L-shell charge states. The emitted spectra have been studied in high resolution using crystal, grating, and x-ray calorimeter spectrometers. In particular, wavelengths of n = 0 M-shell transitions in K-like W55+ through Ne-like W64+, and intershell transitions in Zn-like W44+ through Co-like W47+ have been measured. Special attention is given to the Ni-like W46+ ion, which has two strong electric-dipole forbidden transitions that are of interest for plasma diagnostics. The EBIT measurements are complemented by spectral modeling using the Flexible Atomic Code (FAC), and predictions for tokamak spectra are presented. The L-shell tungsten ions have been studied at electron-beam energies of up to 122 keV and transition energies measured in Ne-like W64+ through Li-like W71+. These spectra constitute the physics basis in the design of the ion-temperature crystal spectrometer for the ITER tokamak. Tungsten particles have furthermore been introduced into the Sustained Spheromak Physics Experiment (SSPX) spheromak in Livermore in order to investigate diagnostic possibilities of extreme ultraviolet tungsten spectra for the ITER divertor. The spheromak measurement and spectral modeling using FAC suggest that tungsten ions in charge states around Er-like W6+ could be useful for

  4. Micro-Raman spectroscopy of plagioclase and maskelynite in Martian meteorites: Evidence of progressive shock metamorphism

    OpenAIRE

    Fritz,Jorg; Greshake,Ansgar; Stoffler,Dieter

    2005-01-01

    We present the first systematic Micro-Raman spectroscopic investigation of plagioclase of different degree of shock metamorphism in Martian meteorites. The equilibrium shock pressure of all plagioclase phases of seventeen unpaired Martian meteorites was determined by measuring the shock-induced reduction of the refractive index. Systematic variations in the recorded Raman spectra of the plagioclase phases correlate with increasing shock pressure. In general, the shock induced deformation of t...

  5. Role of hydration in the phase transition of polypeptides investigated by NMR and Raman spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Dybal, Jiří; Schmidt, Pavel; Kříž, Jaroslav; Kurková, Dana; Rodriguez-Cabello, J. C.; Alonso, M.

    2004-01-01

    Roč. 205, - (2004), s. 143-150 ISSN 1022-1360 R&D Projects: GA AV ČR IAA4050208 Institutional research plan: CEZ:AV0Z4050913 Keywords : NMR * quantum chemistry * Raman spectroscopy Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.691, year: 2004

  6. Resonance Raman investigation of the radical cation of 1,3,5-hexatriene

    DEFF Research Database (Denmark)

    Keszhelyi, T.; Wilbrandt, R.; Cave, R.J.

    1994-01-01

    The resonance Raman spectrum of the 1,3,5-hexatriene radical cation generated by gamma-irradiation in a Freon glass is reported. The spectrum is excited at 395 nm in resonance with the second absorption band. Identical spectra are obtained from ionized (E)- and (Z)-1,3,5-hexatriene. The presence...

  7. Investigation of Raman chemical imaging for detection of Lycopene changes in tomatoes during postharvest ripening

    Science.gov (United States)

    Lycopene is a major carotenoid in tomatoes and detecting changes in lycopene content can be used to monitor the ripening of tomatoes. Raman chemical imaging is a new technique that shows promise for mapping constituents of interest in complex food matrices. In this study, a benchtop point-scanning...

  8. Non-invasive in vivo determination of the carotenoids beta-carotene and lycopene concentrations in the human skin using the Raman spectroscopic method

    Energy Technology Data Exchange (ETDEWEB)

    Darvin, M E [Center of Experimental and Applied Cutaneous Physiology (CCP), Department of Dermatology, Charite University Hospital, Berlin (Germany); Gersonde, I [Institute of Medical Physics and Laser Medicine, Charite University Hospital, Berlin (Germany); Meinke, M [Institute of Medical Physics and Laser Medicine, Charite University Hospital, Berlin (Germany); Sterry, W [Center of Experimental and Applied Cutaneous Physiology (CCP), Department of Dermatology, Charite University Hospital, Berlin (Germany); Lademann, J [Center of Experimental and Applied Cutaneous Physiology (CCP), Department of Dermatology, Charite University Hospital, Berlin (Germany)

    2005-08-07

    Resonance Raman spectroscopy was used as a fast and non-invasive optical method of measuring the absolute concentrations of beta-carotene and lycopene in living human skin. Beta-carotene and lycopene have different absorption values at 488 and 514.5 nm and, consequently, the Raman lines for beta-carotene and lycopene have different scattering efficiencies at 488 and 514.5 nm excitations. These differences were used for the determination of the concentrations of beta-carotene and lycopene. Using multiline Ar{sup +} laser excitation, clearly distinguishable carotenoid Raman spectra can be obtained which are superimposed on a large fluorescence background. The Raman signals are characterized by two prominent Stokes lines at 1160 and 1525 cm{sup -1}, which have nearly identical relative intensities. Both substances were detected simultaneously. The Raman spectra are obtained rapidly, i.e. within about 10 s, and the required laser light exposure level is well within safety standards. The disturbance of the measurements by non-homogeneous skin pigmentation was avoided by using a relatively large measuring area of 35 mm{sup 2}. It was shown that beta-carotene and lycopene distribution in human skin strongly depends upon the skin region studied and drastically changed inter-individually. Skin beta-carotene and lycopene concentrations are lower in smokers than in non-smokers and higher in the vegetarian group.

  9. Non-invasive in vivo determination of the carotenoids beta-carotene and lycopene concentrations in the human skin using the Raman spectroscopic method

    International Nuclear Information System (INIS)

    Darvin, M E; Gersonde, I; Meinke, M; Sterry, W; Lademann, J

    2005-01-01

    Resonance Raman spectroscopy was used as a fast and non-invasive optical method of measuring the absolute concentrations of beta-carotene and lycopene in living human skin. Beta-carotene and lycopene have different absorption values at 488 and 514.5 nm and, consequently, the Raman lines for beta-carotene and lycopene have different scattering efficiencies at 488 and 514.5 nm excitations. These differences were used for the determination of the concentrations of beta-carotene and lycopene. Using multiline Ar + laser excitation, clearly distinguishable carotenoid Raman spectra can be obtained which are superimposed on a large fluorescence background. The Raman signals are characterized by two prominent Stokes lines at 1160 and 1525 cm -1 , which have nearly identical relative intensities. Both substances were detected simultaneously. The Raman spectra are obtained rapidly, i.e. within about 10 s, and the required laser light exposure level is well within safety standards. The disturbance of the measurements by non-homogeneous skin pigmentation was avoided by using a relatively large measuring area of 35 mm 2 . It was shown that beta-carotene and lycopene distribution in human skin strongly depends upon the skin region studied and drastically changed inter-individually. Skin beta-carotene and lycopene concentrations are lower in smokers than in non-smokers and higher in the vegetarian group

  10. Electrochemical and spectroscopic investigations of immobilized de novo designed heme proteins on metal electrodes

    DEFF Research Database (Denmark)

    Albrecht, Tim; Li, WW; Ulstrup, Jens

    2005-01-01

    On the basis of rational design principles, template-assisted four-helix-bundle proteins that include two histidines for coordinative binding of a heme were synthesized. Spectroscopic and thermodynamic characterization of the proteins in solution reveals the expected bis-histidine coordinated heme...

  11. Spectroscopic and laser investigations of Nd3+ and Yb3+ in rare-earth oxyborates

    International Nuclear Information System (INIS)

    Lupei, A.; Lupei, V.; Gheorghe, L.; Aka, G.; Vivien, D.; Antic- Fidancev, E.

    2002-01-01

    Since 1997 a new class of non-linear crystals have been intensively investigated, the rare-earth and calcium oxyborates RECa 4 O(BO 3 ) 4 -RECOB (especially with RE 3+ = Y 3+ or Gd 3+ ). These crystals can be grown from melt and have large effective non-linear coefficients; they present a large transparence range from 0.2-5 mm, are non-hygroscopic, have a high damage threshold, can be doped with large concentrations of laser active ions, etc. Undoped these crystals are good doublers and doped with Nd 3+ or Yb 3+ they can be used in the self - conversion regime for transformation of the infrared radiation into green, blue or red. A series of fundamental structural, spectroscopic and laser emission characteristics of Nd 3+ or Yb 3+ doped RECOB are still under study. Thus, one important aspect discussed in literature is the degree of disorder of RECOB crystals. The research performed in the frame of CERES project was devoted to the growth of the of RECOB crystals doped with Nd 3+ or Yb 3+ , structural investigations and high-resolution optical spectral investigations and Nd 3+ laser emission. The growth of RECa 4 O(BO) 3 (Y 3+ and Gd 3+ ) single crystals was performed with an ADL furnace by using Czochralski method. Good optical crystals were obtained on direction; X-ray structural studies were also performed. The low temperatures high-resolution optical spectral measurements on Nd 3+ and Yb 3+ doped GdCOB and YCOB allowed the clarification of some structural characteristics of these crystals. Two problems were studied: the intrinsic structure of undoped crystals and the doping effects. Studies revealed for the first time by optical spectroscopy essential differences between GdCOB and YCOB crystals; they refer to the satellite structure of Yb 3+ or Nd 3+ and inhomogeneous broadening, indicating a disordered structure much larger for YCOB, qualitatively in accord with recent X-ray results. Based on spectral, emission decay and structural investigations, models for

  12. Investigation of attractive and repulsive interactions associated with ketones in supercritical CO2, based on Raman spectroscopy and theoretical calculations.

    Science.gov (United States)

    Kajiya, Daisuke; Saitow, Ken-ichi

    2013-08-07

    Carbonyl compounds are solutes that are highly soluble in supercritical CO2 (scCO2). Their solubility governs the efficiency of chemical reactions, and is significantly increased by changing a chromophore. To effectively use scCO2 as solvent, it is crucial to understand the high solubility of carbonyl compounds, the solvation structure, and the solute-solvent intermolecular interactions. We report Raman spectroscopic data, for three prototypical ketones dissolved in scCO2, and four theoretical analyses. The vibrational Raman spectra of the C=O stretching modes of ketones (acetone, acetophenone, and benzophenone) were measured in scCO2 along the reduced temperature Tr = T∕Tc = 1.02 isotherm as a function of the reduced density ρr = ρ∕ρc in the range 0.05-1.5. The peak frequencies of the C=O stretching modes shifted toward lower energies as the fluid density increased. The density dependence was analyzed by using perturbed hard-sphere theory, and the shift was decomposed into attractive and repulsive energy components. The attractive energy between the ketones and CO2 was up to nine times higher than the repulsive energy, and its magnitude increased in the following order: acetone attractive energy and optimized the relative configuration between each solute and CO2. According to theoretical calculations for the dispersion energy, the dipole-induced-dipole interaction energy, and the frequency shift due to their interactions, the experimentally determined attractive energy differences in the three solutes were attributed to the dispersion energies that depended on a chromophore attached to the carbonyl groups. It was found that the major intermolecular interaction with the attractive shift varied from dipole-induced dipole to dispersion depending on the chromophore in the ketones in scCO2. As the common conclusion for the Raman spectral measurements and the four theoretical calculations, solute polarizability, modified by the chromophore, was at the core of

  13. Spectroscopic [FT-IR and FT-Raman] and theoretical [UV-Visible and NMR] analysis on α-Methylstyrene by DFT calculations.

    Science.gov (United States)

    Karthikeyan, N; Joseph Prince, J; Ramalingam, S; Periandy, S

    2015-05-15

    In the present research work, the FT-IR, FT-Raman and (13)C and (1)H NMR spectra of the α-Methylstyrene were recorded. The observed fundamental frequencies in finger print as well as functional group regions were assigned according to their uniqueness region. The Gaussian computational calculations are carried out by HF and DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results were tabulated. The impact of the presence of vinyl group in phenyl structure of the compound is investigated. The modified vibrational pattern of the molecule associated vinyl group was analyzed. Moreover, (13)C NMR and (1)H NMR were calculated by using the gauge independent atomic orbital (GIAO) method with B3LYP methods and the 6-311++G(d,p) basis set and their spectra were simulated and the chemical shifts linked to TMS were compared. A study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies were carried out. The kubo gap of the present compound was calculated related to HOMO and LUMO energies which confirm the occurring of charge transformation between the base and ligand. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. The NLO properties related to Polarizability and hyperpolarizability based on the finite-field approach were also discussed. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  14. Spectroscopic investigation of indium halides as substitudes of mercury in low pressure discharges for lighting applications

    Energy Technology Data Exchange (ETDEWEB)

    Briefi, Stefan

    2012-05-22

    Low pressure discharges with indium halides as radiator are discussed as substitutes for hazardous mercury in conventional fluorescent lamps. In this work, the applicability of InBr and InCl in a low pressure discharge light source is investigated. The aim is to identify and understand the physical processes which determine the discharge characteristics and the efficiency of the generated near-UV emission of the indium halide molecule and of the indium atom which is created due to dissociation processes in the plasma. As discharge vessels sealed cylindrical quartz glass tubes which contain a defined amount of indium halide and a rare gas are used. Preliminary investigations showed that for a controlled variation of the indium halide density a well-defined cold spot setup is mandatory. This was realized in the utilized experimental setup. The use of metal halides raises the issue, that power coupling by internal electrodes is not possible as the electrodes would quickly be eroded by the halides. The comparison of inductive and capacitive RF-coupling with external electrodes revealed that inductively coupled discharges provide higher light output and much better long term stability. Therefore, all investigations are carried out using inductive RF-coupling. The diagnostic methods optical emission and white light absorption spectroscopy are applied. As the effects of absorption-signal saturation and reabsorption of emitted radiation within the plasma volume could lead to an underestimation of the determined population densities by orders of magnitude, these effects are considered in the data evaluation. In order to determine the electron temperature and the electron density from spectroscopic measurements, an extended corona model as population model of the indium atom has been set up. A simulation of the molecular emission spectra has been implemented to investigate the rovibrational population processes of the indium halide molecules. The impact of the cold spot

  15. Qualitative and quantitative changes in phospholipids and proteins investigated by spectroscopic techniques in olfactory bulbectomy animal depression model.

    Science.gov (United States)

    Depciuch, J; Parlinska-Wojtan, M

    2018-01-30

    Depression becomes nowadays a high mortality civilization disease with one of the potential causes being impaired smell. In this study Raman, Fourier Transform Infra Red (FTIR) and Ultraviolet-Visible (UV-vis) spectroscopies were used to determine the changes in the quantity and structure of phospholipids and proteins in the blood serum of bulbectomized rats (OB_NaCl), which is a common animal depression model. The efficiency of amitriptyline (AMI) treatment was also evaluated. The obtained results show a significant decrease in the phospholipid and protein fractions (as well as changes in their secondary structures) in blood serum of bulbectomized rats. AMI treatment in bulbectomized rats increased protein level and did not affect the level of phospholipids. Structural information from phospholipids and proteins was obtained from UV-vis spectroscopy combined with the second derivative of the FTIR spectra. Indeed, the structure of proteins in blood serum of bulbectomized rats was normalized after amitriptyline therapy, while the damaged structure of phospholipids remained unaffected. These findings strongly suggest that impaired smell could be one of the causes of depression and may induce permanent (irreversible) damages into the phospholipid structure identified as shortened carbon chains. This study shows a possible new application of spectroscopic techniques in the diagnosis and therapy monitoring of depression. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Corrosion investigation of fire-gilded bronze involving high surface resolution spectroscopic imaging

    International Nuclear Information System (INIS)

    Masi, G.; Chiavari, C.; Avila, J.; Esvan, J.; Raffo, S.; Bignozzi, M.C.; Asensio, M.C.; Robbiola, L.

    2016-01-01

    Graphical abstract: - Highlights: • Fire-gilded bronze prepared by ancient methods (Au–Hg layer on Cu–Sn–Zn–Pb–Sb). • Heating during gilding induces Sn and Znenrichment in the top part of the gilded layer. • SR-HRPES mapping of corrosion craters (cross-section) after accelerated ageing. • Selective dissolution of Cu and Zn in the craters induces Sn species enrichment. • The main species in the craters are related to hydroxi-oxide compounds. - Abstract: Gilded bronzes are often affected by severe corrosion, due to defects in the Au layer and Au/Cu alloy galvanic coupling, stimulated by large cathodic area of the gilded layer. Galvanic corrosion, triggered by gilding defects, leads to products growth at the Au/bronze interface, inducing blistering or break-up of the Au layer. In this context, fire-gilded bronze replicas prepared by ancient methods (use of spreadable Au–Hg paste) was specifically characterised by compiling complementary spectroscopic and imaging information before/after accelerated ageing with synthetic rain. Fire-gilded bronze samples were chemically imaged in cross-section at nano-metric scale (<200 nm) using high energy and lateral resolution synchrotron radiation photoemission (HR-SRPES) of core levels and valence band after conventional characterisation of the samples by Glow Discharge optical Emission Spectroscopy (GD-OES) and conventional X-ray photoelectron spectroscopy (XPS). We have found a net surface enrichment in Zn and Sn after fire-gilding and presence of metallic Hg, Pb and Cu within the Au layer. Moreover, the composition distribution of the elements together with their oxidation has been determined. It was also revealed that metallic phases including Hg and Pb remain in the gilding after corrosion. Moreover, selective dissolution of Zn and Cu occurs in the crater due to galvanic coupling, which locally induces relative Sn species enrichment (decuprification). The feasibility advantages and disadvantages of

  17. Corrosion investigation of fire-gilded bronze involving high surface resolution spectroscopic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Masi, G., E-mail: giulia.masi5@unibo.it [Dipartimento di Ingegneria Civile, Chimica, Ambientale e dei Materiali, Università di Bologna, via Terracini 28, 40131 Bologna (Italy); Chiavari, C., E-mail: cristina.chiavari@unibo.it [Dipartimento di Ingegneria Civile, Chimica, Ambientale e dei Materiali, Università di Bologna, via Terracini 28, 40131 Bologna (Italy); C.I.R.I. (Centro Interdipartimentale Ricerca Industriale) Meccanica Avanzata e Materiali, Università di Bologna, Bologna, via Terracini 28, 40131 Bologna (Italy); Avila, J., E-mail: jose.avila@synchrotron-soleil.fr [Synchrotron SOLEIL, L’Orme des Merisiers, 91190 Saint-Aubin (France); Esvan, J., E-mail: jerome.esvan@ensiacet.fr [Centre Interuniversitaire de Recherche et d’Ingénierie des Matériaux, Université de Toulouse, 4 allée Emile Monso, 31030 Toulouse (France); Raffo, S., E-mail: simona.raffo2@unibo.it [Dipartimento di Chimica Industriale “Toso Montanari”, Università di Bologna, viale Risorgimento 4, 40136 Bologna (Italy); Bignozzi, M.C., E-mail: maria.bignozzi@unibo.it [Dipartimento di Ingegneria Civile, Chimica, Ambientale e dei Materiali, Università di Bologna, via Terracini 28, 40131 Bologna (Italy); Asensio, M.C., E-mail: maria-carmen.asensio@synchrotron-soleil.fr [Synchrotron SOLEIL, L’Orme des Merisiers, 91190 Saint-Aubin (France); Robbiola, L., E-mail: robbiola@univ-tlse2.fr [TRACES Lab (CNRS UMR5608), Université Toulouse Jean-Jaurès, 5, allées Antonio-Machado, 31058 Toulouse (France); and others

    2016-03-15

    Graphical abstract: - Highlights: • Fire-gilded bronze prepared by ancient methods (Au–Hg layer on Cu–Sn–Zn–Pb–Sb). • Heating during gilding induces Sn and Znenrichment in the top part of the gilded layer. • SR-HRPES mapping of corrosion craters (cross-section) after accelerated ageing. • Selective dissolution of Cu and Zn in the craters induces Sn species enrichment. • The main species in the craters are related to hydroxi-oxide compounds. - Abstract: Gilded bronzes are often affected by severe corrosion, due to defects in the Au layer and Au/Cu alloy galvanic coupling, stimulated by large cathodic area of the gilded layer. Galvanic corrosion, triggered by gilding defects, leads to products growth at the Au/bronze interface, inducing blistering or break-up of the Au layer. In this context, fire-gilded bronze replicas prepared by ancient methods (use of spreadable Au–Hg paste) was specifically characterised by compiling complementary spectroscopic and imaging information before/after accelerated ageing with synthetic rain. Fire-gilded bronze samples were chemically imaged in cross-section at nano-metric scale (<200 nm) using high energy and lateral resolution synchrotron radiation photoemission (HR-SRPES) of core levels and valence band after conventional characterisation of the samples by Glow Discharge optical Emission Spectroscopy (GD-OES) and conventional X-ray photoelectron spectroscopy (XPS). We have found a net surface enrichment in Zn and Sn after fire-gilding and presence of metallic Hg, Pb and Cu within the Au layer. Moreover, the composition distribution of the elements together with their oxidation has been determined. It was also revealed that metallic phases including Hg and Pb remain in the gilding after corrosion. Moreover, selective dissolution of Zn and Cu occurs in the crater due to galvanic coupling, which locally induces relative Sn species enrichment (decuprification). The feasibility advantages and disadvantages of

  18. Spectroscopic analysis of 8-hydroxyquinoline-5-sulphonic acid and investigation of its reactive properties by DFT and molecular dynamics simulations

    Science.gov (United States)

    Sureshkumar, B.; Sheena Mary, Y.; Panicker, C. Yohannan; Resmi, K. S.; Suma, S.; Armaković, Stevan; Armaković, Sanja J.; Van Alsenoy, C.

    2017-12-01

    A detailed interpretation of the FT-IR and FT-Raman spectra has been performed on the basis of the observed and calculated infrared and Raman spectra as well as calculated potential energy distribution values. Comparison of Raman and SERS spectra suggests a tilted orientation of the rings on the metal surface. The dipole moment, polarizability and first and second order hyperpolarizability values of the molecule were calculated. Global reactivity parameters were predicted. The relative reactivities towards electrophilic and nucleophilic attack are predicted using molecular electrostatic potential map. Average local ionization energy (ALIE) and Fukui functions have been inspected in order to investigate local reactivity properties of title molecule. The importance of autoxidation and hydrolysis mechanisms for the title molecule has been assessed by DFT calculations of bond dissociation energies (BDE) and by calculations of radial distribution functions (RDFs) after molecular dynamics (MD) simulations. Molecular docking studies suggest that the title compound can be a lead compound for developing new anti-cancerous drug.

  19. FTIR, FT-Raman, FT-NMR and quantum chemical investigations of 3-acetylcoumarin

    Science.gov (United States)

    Arjunan, V.; Sakiladevi, S.; Marchewka, M. K.; Mohan, S.

    2013-05-01

    3-Acetylcoumarin (3AC) was synthesised by a Knoevenagel reaction. Conformational analysis using the B3LYP method was also carried out to determine the most stable conformation of the compound. FTIR and FT-Raman spectra of 3AC have been recorded in the range 4000-400 and 4000-100 cm-1, respectively. 1H and 13C NMR spectra have also been recorded. The complete vibrational assignment and analysis of the fundamental modes of the compound were carried out using the experimental FTIR and FT-Raman data and quantum mechanical studies. The experimental vibrational frequencies were compared with the wavenumbers obtained theoretically from the DFT-B3LYP/B3PW91 gradient calculations employing the standard 6-31G**, high level 6-311++G** and cc-pVTZ basis sets for optimised geometry of the compound. The frontier molecular orbital energies of the compound are determined by DFT method.

  20. Investigating the effects of Pentoxifylline on human breast cancer cells using Raman spectroscopy

    Directory of Open Access Journals (Sweden)

    Peeyush N. Goel

    2015-03-01

    Full Text Available Breast cancer is one of the leading causes of cancer-related deaths in a global scenario. In the present study, biochemical changes exerted upon Pentoxifylline (PTX treatment had been appraised in human breast cancer cells using Raman spectroscopy. There are no clinically approved methods to monitor such therapeutic responses available. The spectral profiling is suggestive of changes in DNA, protein and lipid contents showing a linear relationship with drug dosage. Further, multivariate analysis using principal-component based linear-discriminant-analysis (PC-LDA was employed for classifying the control and the PTX treated groups. These findings support the feasibility of Raman spectroscopy as an alternate/adjunct label-free, objective method for monitoring drug-induced modifications against breast cancer cells.

  1. Investigating Functional Extension of Optical Coherence Tomography for Spectroscopic Analysis of Blood Oxygen Saturation

    Science.gov (United States)

    Chen, Siyu

    Over the past two decades, optical coherence tomography (OCT) has been successfully applied to various fields of biomedical researching and clinical studies, including cardiology, urology, dermatology, dentistry, oncology, and most successfully, ophthalmology. This dissertation seeks to extend the current OCT practice, which is still largely morphology-based, into a new dimension, functional analysis of metabolic activities in vivo. More specifically, the investigation is focused on retrieving blood oxygen saturation (sO2) using intrinsic hemoglobin optical absorption contrast. Most mammalian cells rely on aerobic respiration to support cellular function, which means they consume oxygen to create adenosine triphosphate (ATP). Metabolic rate of oxygen (MRO2), a key hemodynamic parameter, characterizes how much oxygen is consumed during a given period of time, reflecting the metabolic activity of the target tissue. For example, retinal neurons are highly active and almost entirely rely on the moment-to-moment oxygen supply from retinal circulations. Thus, variation in MRO2 reveals the instantaneous activity of these neurons, shedding light on the physiological and pathophysiological change of cellular functions. Eventually, measuring MRO2 can potentially provide a biomarker for early-stage disease diagnosis, and serve as one benchmark for evaluating effectiveness of medical intervention during disease management. Essential in calculating MRO2, blood sO2 measurements using spectroscopic OCT analysis has been attempted as early as 2003. OCT is intrinsically sensitive to the blood optical absorption spectrum due to its wide-band illumination and detection scheme relying on back-scattered photon. However, accurate retrieval of blood sO2 using conventional near infrared (NIR) OCT systems in vivo has remained challenging. It was not until the development of OCT systems using visible light illumination (vis-OCT) when accurate measurement of blood sO2 was reported in live

  2. Structural changes of human RNase L upon homodimerization investigated by Raman spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Kříž, M.; Snášel, Jan; Kopecký, V. Jr.; Páv, Ondřej; Rosenberg, Ivan; Štepánek, J.

    2012-01-01

    Roč. 1824, č. 9 (2012), s. 1039-1044 ISSN 1570-9639 R&D Projects: GA ČR GA202/09/0193; GA AV ČR KAN200520801 Grant - others:GA AV ČR(CZ) KJB101120805 Program:KJ Institutional support: RVO:61388963 Keywords : RNase L * Raman spectroscopy * DCDR spectroscopy * phosphonate oligoadenylate * ligand binding Subject RIV: BO - Biophysics Impact factor: 3.733, year: 2012

  3. Raman spectroscopy in investigations of mechanism of binding of human serum albumin to molecular probe fluorescein

    International Nuclear Information System (INIS)

    Vlasova, I M; Saletsky, A M

    2008-01-01

    The mechanism of binding of molecular probe fluorescein to molecules of human serum albumin was studied by the Raman spectroscopy method. The position of binding Center on human serum albumin molecule for fluorescein is determined. The amino acid residues of albumin molecule, participating in binding of fluorescein at different pH values of solution, are established. The conformation rearrangements of globules of human serum albumin, taking place at binding of fluorescein at different pH values of solution, are registered

  4. High-pressure Raman investigations of phase transformations in pentaerythritol (C(CH sub 2 OH) sub 4)

    CERN Document Server

    Bhattacharya, T

    2002-01-01

    Our high-pressure Raman scattering experiments on pentaerythritol (C(CH sub 2 OH) sub 4) show that this compound undergoes at least three phase transformations up to 25 GPa. Splitting of various modes at approx 6.3, approx 8.2 and 10 GPa suggests that these phase transformations result in lowering of crystalline symmetry. A very small discontinuous change in slope of most of the Raman-active modes is observed at 0.3 GPa. However, no other signature of a phase transition was observed at this pressure. The observed correlation of the pressures for the onset of the two phase transformations with the limiting values of the distances between various non-bonded atoms in the parent phase suggests that the molecular rearrangements across the phase transformations are not very drastic. In addition, our earlier Fourier transform infrared and present Raman investigations indicate that high-pressure compression leads to increase in strength of the hydrogen bond present in this compound.

  5. FTIR, FT-Raman, FT-NMR, UV-visible and quantum chemical investigations of 2-amino-4-methylbenzothiazole.

    Science.gov (United States)

    Arjunan, V; Sakiladevi, S; Rani, T; Mythili, C V; Mohan, S

    2012-03-01

    The FT-IR (4000-400 cm(-1)) and FT-Raman (4000-100 cm(-1)) spectral measurements and complete assignments of the observed spectra of 2-amino-4-methylbenzothiazole (2A4MBT) have been proposed. Ab initio and DFT calculations have been performed and the structural parameters of the compound were determined from the optimised geometry with 6-31G(d,p), 6-311++G(d,p) and cc-pVDZ basis sets and giving energies, harmonic vibrational frequencies, depolarisation ratios, IR intensities and Raman activities. (1)H and (13)C NMR spectra were recorded and (1)H and (13)C nuclear magnetic resonance chemical shifts of the molecule were calculated using the gauge independent atomic orbital (GIAO) method. UV-visible spectrum of the compound was also recorded and the electronic properties, such as HOMO, LUMO and band gap energies were measured by time-dependent DFT (TD-DFT) approach. The geometric parameters, energies, harmonic vibrational frequencies, IR intensities, Raman activities chemical shifts and absorption wavelengths were compared with the available experimental data of the molecule. The influences of methyl and amino groups on the skeletal modes and on the proton chemical shifts have been investigated. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Electrochemical activation of Li2MnO3 at elevated temperature investigated by in situ Raman microscopy

    International Nuclear Information System (INIS)

    Lanz, Patrick; Villevieille, Claire; Novák, Petr

    2013-01-01

    Layered-layered oxides of the type xLi 2 MnO 3 ·(1 − x)LiMO 2 (M = Mn, Ni, Co) have been postulated to contain Li 2 MnO 3 domains which, upon electrochemical activation, give rise to a characteristic potential plateau at 4.5 V vs. Li + /Li. To improve our understanding of the complex reaction mechanisms at play, we applied in situ Raman microscopy to investigate the constituent Li 2 MnO 3 . Li 2 MnO 3 synthesised via a two-step solid-state reaction was characterised by scanning electron microscopy and X-ray diffraction. Preliminary electrochemical tests and ex situ Raman microscopy showed the need for elevated temperatures to achieve activation. For the first time, in situ Raman microscopy (at 50 °C) confirmed the activation of Li 2 MnO 3 . The main signal at 615 cm −1 shifted to higher wavenumbers upon charging. After reaching 4.4 V vs. Li + /Li, this shift grew significantly, which is in good agreement with the onset of the potential plateau in both Li 2 MnO 3 and xLi 2 MnO 3 ·(1 − x)LiMO 2 , and is assigned to the partial formation of a spinel-like phase

  7. Investigation and measures to noise on spectroscopic measurement system in JT-60U

    International Nuclear Information System (INIS)

    Nagaya, Susumu; Kubo, Hirotaka; Sugie, Tatsuo; Onizawa, Masami; Kawai, Isao; Nakata, Hisao.

    1997-11-01

    Breakdown of a negative-ion-based neutral beam injection (N-NBI) has caused noise trouble to several systems. The control circuit of a spectroscopic measurement system had not well worked because of the noise. The noise has been measured by an optical-fiber isolation system during operation of JT-60U. The amplitude and the frequency were 15-18 V and 15 MHz respectively. The transmission noise has been reduced by putting ferrite cores to all cables connecting with the control circuits. As a result, the trouble with the spectroscopic measurement system has completely been solved. Adding condensers and resistors to the circuit was not effective to reduce the noise. (author)

  8. A Raman scattering and FT-IR spectroscopic study on the effect of the solar radiation in Antarctica on bovine cornea

    Science.gov (United States)

    Yamamoto, Tatsuyuki; Murakami, Naoki; Yoshikiyo, Keisuke; Takahashi, Tetsuya; Yamamoto, Naoyuki

    2010-01-01

    The Raman scattering and FT-IR spectra of the corneas, transported to the Syowa station in Antarctica and exposed to the solar radiation of the mid-summer for four weeks, were studied to reveal that type IV collagen involved in corneas were fragmented. The amide I and III Raman bands were observed at 1660 and 1245 cm -1, respectively, and the amide I and II infrared bands were observed at 1655 and 1545 cm -1, respectively, for original corneas before exposure. The background of Raman signals prominently increased and the ratio of amide II infrared band versus amide I decreased by the solar radiation in Antarctica. The control experiment using an artificial UV lamp was also performed in laboratory. The decline rate of the amide II/amide I was utilized for estimating the degree of fragmentation of collagen, to reveal that the addition of vitamin C suppressed the reaction while the addition of sugars promoted it. The effect of the solar radiation in Antarctica on the corneas was estimated as the same as the artificial UV lamp of four weeks (Raman) or one week (FT-IR) exposure.

  9. Infrared and Raman spectroscopic characterization of the silicate mineral olmiite CaMn2+[SiO3(OH)](OH) - implications for the molecular structure

    Science.gov (United States)

    Frost, Ray L.; Scholz, Ricardo; López, Andrés; Xi, Yunfei; Granja, Amanda; Žigovečki Gobac, Željka; Lima, Rosa Malena Fernandes

    2013-12-01

    We have studied the mineral olmiite CaMn[SiO3(OH)](OH) which forms a series with its calcium analogue poldervaartite CaCa[SiO3(OH)](OH) using a range of techniques including scanning electron microscopy, thermogravimetric analysis, Raman and infrared spectroscopy. Chemical analysis shows the mineral is pure and contains only calcium and manganese in the formula. Thermogravimetric analysis proves the mineral decomposes at 502 °C with a mass loss of 8.8% compared with the theoretical mass loss of 8.737%. A strong Raman band at 853 cm-1 is assigned to the SiO stretching vibration of the SiO3(OH) units. Two Raman bands at 914 and 953 cm-1 are attributed to the antisymmetric vibrations. Two intense Raman bands observed at 3511 and 3550 cm-1 are assigned to the OH stretching vibration of the SiO3(OH) units. The observation of multiple OH bands supports the concept of the non-equivalence of the OH units. Vibrational spectroscopy enables a detailed assessment of the molecular structure of olmiite.

  10. Spectroscopic investigation of ELM phenomena in the ASDEX-Upgrade divertor with high time resolution

    International Nuclear Information System (INIS)

    Field, A.R.; Buechl, K.; Fuchs, C.J.; Fussmann, G.; Herrmann, A.; Lieder, G.; Napiontek, B.; Radtke, R.; Wenzel, U.; Zohm, H.

    1993-01-01

    Improved tokamak H-mode confinement is associated with the formation of an insulating zone just within the separatrix. At a critical pressure gradient a sudden burst of MHD activity (an ELM) degrades edge confinement, releasing particles and energy into the scrape-off layer (SOL) which is subsequently transported to the divertor. Here, these phenomena are studied using spectroscopic diagnostics and target plate thermography of high spatial and temporal resolution. (author) 3 refs., 6 figs

  11. Spectroscopic investigation of ELM phenomena in the ASDEX-Upgrade divertor with high time resolution

    Energy Technology Data Exchange (ETDEWEB)

    Field, A R; Buechl, K; Fuchs, C J; Fussmann, G; Herrmann, A; Lieder, G; Napiontek, B; Radtke, R; Wenzel, U; Zohm, H [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

    1994-12-31

    Improved tokamak H-mode confinement is associated with the formation of an insulating zone just within the separatrix. At a critical pressure gradient a sudden burst of MHD activity (an ELM) degrades edge confinement, releasing particles and energy into the scrape-off layer (SOL) which is subsequently transported to the divertor. Here, these phenomena are studied using spectroscopic diagnostics and target plate thermography of high spatial and temporal resolution. (author) 3 refs., 6 figs.

  12. Atomic emission spectroscopic investigations for determining depth profiles at boride layers on iron materials

    International Nuclear Information System (INIS)

    Danzer, K.; Marx, G.

    1980-01-01

    A combination of atomic emission spectroscopic surface analysis and mechanical removement of defined surface areas in layers by grinding yields information about the depth distribution of boron in iron. In addition, the evaluation with the aid of the two-dimensional variance analysis leads to statements on the homogeneous distribution within individual layers at different depth. The results obtained in this way are in agreement with those of other methods

  13. A XANES and Raman investigation of sulfur speciation and structural order in Murchison and Allende meteorites

    Science.gov (United States)

    Bose, M.; Root, R. A.; Pizzarello, S.

    2017-03-01

    Insoluble organic matter (IOM) and hydrothermally treated IOM extracted from two carbonaceous chondrites, Murchison and Allende, was studied using sulfur K-edge XANES (X-ray absorption near edge structure) and μ-Raman spectroscopy, with the aim to understand their IOM's sulfur speciation and structural order, and how aqueous alteration or thermal metamorphism may have transformed these materials. We found that the sulfur-functional group chemistry of both the Murchison IOM and hydrothermally treated IOM samples have a large chemical variability ranging from oxidation states of S-2 to S+6, and exhibit a transformation in their oxidation state after the hydrothermal treatment (HT) to produce thiophenes and thiol compounds. Sulfoxide and sulfite peaks are also present in Murchison. Sulfates considered intrinsic to Murchison are most likely preaccretionary in nature, and not a result of reactions with water at high temperatures on the asteroid parent body. We argue that the reduced sulfides may have formed in the CM parent body, while the thiophenes and thiol compounds are a result of the HT. Micro-Raman spectra show the presence of aliphatic and aromatic moieties in Murchison's material as observed previously, which exhibits no change after HT. Because the Murchison IOM was modified, as seen by XANES analysis, absence of a change observed using micro-Raman indicated that although the alkyl carbons of IOM were cleaved, the aromatic network was not largely modified after HT. By contrast, Allende IOM contains primarily disulfide and elemental sulfur, no organic sulfur, and shows no transformation after HT. This nontransformation of Allende IOM after HT would indicate that parent body alteration of sulfide to sulfate is not feasible up to temperatures of 300°C. The reduced sulfur products indicate extreme secondary chemical processing from the precursor compounds in its parent body at temperatures as high as 624°C, as estimated from μ-Raman D band parameters. The

  14. Global approach for the validation of an in-line Raman spectroscopic method to determine the API content in real-time during a hot-melt extrusion process.

    Science.gov (United States)

    Netchacovitch, L; Thiry, J; De Bleye, C; Dumont, E; Cailletaud, J; Sacré, P-Y; Evrard, B; Hubert, Ph; Ziemons, E

    2017-08-15

    Since the Food and Drug Administration (FDA) published a guidance based on the Process Analytical Technology (PAT) approach, real-time analyses during manufacturing processes are in real expansion. In this study, in-line Raman spectroscopic analyses were performed during a Hot-Melt Extrusion (HME) process to determine the Active Pharmaceutical Ingredient (API) content in real-time. The method was validated based on a univariate and a multivariate approach and the analytical performances of the obtained models were compared. Moreover, on one hand, in-line data were correlated with the real API concentration present in the sample quantified by a previously validated off-line confocal Raman microspectroscopic method. On the other hand, in-line data were also treated in function of the concentration based on the weighing of the components in the prepared mixture. The importance of developing quantitative methods based on the use of a reference method was thus highlighted. The method was validated according to the total error approach fixing the acceptance limits at ±15% and the α risk at ±5%. This method reaches the requirements of the European Pharmacopeia norms for the uniformity of content of single-dose preparations. The validation proves that future results will be in the acceptance limits with a previously defined probability. Finally, the in-line validated method was compared with the off-line one to demonstrate its ability to be used in routine analyses. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Characterization of prepared In2O3 thin films: The FT-IR, FT-Raman, UV-Visible investigation and optical analysis.

    Science.gov (United States)

    Panneerdoss, I Joseph; Jeyakumar, S Johnson; Ramalingam, S; Jothibas, M

    2015-08-05

    In this original work, the Indium oxide (In2O3) thin film is deposited cleanly on microscope glass substrate at different temperatures by spray pyrolysis technique. The physical properties of the films are characterized by XRD, SEM, AFM and AFM measurements. The spectroscopic investigation has been carried out on the results of FT-IR, FT-Raman and UV-Visible. XRD analysis exposed that the structural transformation of films from stoichiometric to non-stoichiometric orientation of the plane vice versa and also found that, the film is polycrystalline in nature having cubic crystal structure with a preferred grain orientation along (222) plane. SEM and AFM studies revealed that, the film with 0.1M at 500°C has spherical grains with uniform dimension. The complete vibrational analysis has been carried out and the optimized parameters are calculated using HF and DFT (CAM-B3LYP, B3LYP and B3PW91) methods with 3-21G(d,p) basis set. Furthermore, NMR chemical shifts are calculated by using the gauge independent atomic orbital (GIAO) technique. The molecular electronic properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, molecular electrostatic potential energy (MEP) analysis and Polarizability first order hyperpolarizability calculations are performed by time dependent DFT (TD-DFT) approach. The energy excitation on electronic structure is investigated and the assignment of the absorption bands in the electronic spectra of steady compound is discussed. The calculated HOMO and LUMO energies showed the enhancement of energy gap by the addition of substitutions with the base molecule. The thermodynamic properties (heat capacity, entropy, and enthalpy) at different temperatures are calculated and interpreted in gas phase. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  16. Spectroscopic investigation of sulfonate phthalocyanine to probe enzyme reactions for heavy metals detection

    International Nuclear Information System (INIS)

    Chaure, Shweta; Paul, Deepen; Vadagma, Pankaj; Ray, Asim K.

    2010-01-01

    Optical absorption and Raman spectra of the sulfonated copper phthalocyanine (CuTsPc) layer were exploited for detection of cadmium (Cd) contaminants in water. Acetylcholine esterase was immobilized by freely suspending them in calcium alginate microbeads and this gel was then spincoated on the drop cast sulfonated copper phthalocyanine film on a glass substrate to form a bilayer. The inhibition of catalytic reaction between acetylcholine chloride and enzyme due to Cd contaminants was monitored by recording changes in spectra of drop cast CuTsPc as an indicator. The detection limit of cadmium content in water was found to be 1 ppm.

  17. Spectroscopic investigation of sulfonate phthalocyanine to probe enzyme reactions for heavy metals detection

    Energy Technology Data Exchange (ETDEWEB)

    Chaure, Shweta; Paul, Deepen; Vadagma, Pankaj [School of Engineering and Material Science, Queen Mary, University of London, London E1 4NS (United Kingdom); Ray, Asim K., E-mail: a.k.ray@qmul.ac.uk [School of Engineering and Material Science, Queen Mary, University of London, London E1 4NS (United Kingdom)

    2010-01-15

    Optical absorption and Raman spectra of the sulfonated copper phthalocyanine (CuTsPc) layer were exploited for detection of cadmium (Cd) contaminants in water. Acetylcholine esterase was immobilized by freely suspending them in calcium alginate microbeads and this gel was then spincoated on the drop cast sulfonated copper phthalocyanine film on a glass substrate to form a bilayer. The inhibition of catalytic reaction between acetylcholine chloride and enzyme due to Cd contaminants was monitored by recording changes in spectra of drop cast CuTsPc as an indicator. The detection limit of cadmium content in water was found to be 1 ppm.

  18. Molecular docking and spectroscopic investigations aided by density functional theory of Parkinson's drug 2-(3,4-dihydroxyphenyl)ethylamine

    Science.gov (United States)

    Sherlin, Y. Sheeba; Vijayakumar, T.; Roy, S. D. D.; Jayakumar, V. S.

    2018-05-01

    Molecular geometry of Parkinson's drug 2-(3,4-Dihydroxyphenyl)ethylamine hydrochloride (Dopamine, DA) has been evaluated and compared with experimental XRD data. Molecular docking and vibrational spectral analysis of DA have been carried out using FT-Raman and FT-IR spectra aided by Density Functional Theory at B3LYP/6-311++G(d,p). The present investigation deals with the analysis of structural and spectral features responsible for drug activities, nature of hydrogen bonding interactions of the molecule and the correlation of Parkinson's nature with its molecular structural features.

  19. Raman and optical absorption spectroscopic investigation of Yb-Er codoped phosphate glasses containing SiO2

    Institute of Scientific and Technical Information of China (English)

    Youkuo Chen; Lei Wen; Lili Hu; Wei Chen; Y. Guyot; G. Boulon

    2009-01-01

    Yb-Er codoped Na2O-Al2O3-P2Os-xSiO2 glasses containing 0 鈥? 20 mol% SiO2 were prepared successfully. The addition of SiO2 to the phosphate glass not only lengthens the bond between P5+ and non-bridging oxygen but also reduces the number of P=O bond. In contrast with silicate glass in which there is only four-fold coordinated Si4+, most probably there coexist [SiO4] tetrahedron and [SiO6] octahedron in our glasses. Within the range of 0 鈥? 20 mol% SiO2 addition, the stimulated emission cross-section of Er3+ ion only decreases no more than 10%. The Judd-Ofelt intensity parameters of Er3+, 惟.2 does not change greatly, but 惟74 and 惟6 decrease obviously with increasing SiO2 addition, because the bond between Er + and O2- is more strongly covalently bonded.

  20. UV-visible, infrared and Raman spectroscopic and thermal studies of tungsten doped lead borate glasses and the effect of ionizing gamma irradiation

    International Nuclear Information System (INIS)

    El-Kheshen, Amany A.; El-Batal, Fatma H.; Marzouk, Samir Y.

    2008-01-01

    Ultraviolet-visible, infrared and Raman spectroscopy together with thermal properties were measured for undoped and WO 3 - doped (up to 10%) lead borate glasses. Also, the effect of gamma irradiation was followed by UV-visible measurements. The UV visible spectrum of the undoped glass reveals before irradiation intense ultraviolet bands due to the combined effects of trace iron impurities (Fe 3+ ) and Pb 2+ ions which remain unchanged with the addition of WO 3 . Infrared and Raman measurements show characteristic bands due to borate group and the possible sharing of lead-oxygen and tungsten-oxygen groups. The studied glasses show obvious resistance to gamma irradiation. The thermal and density data are correlated with the introduction of highly polarizable and heavy (W 6+ ) ions and to the change in structural arrangement with varying glass composition. (author)

  1. Imidazopyridines as a source of biological activity and their pharmacological potentials-Infrared and Raman spectroscopic evidence of their content in pharmaceuticals and plant materials.

    Science.gov (United States)

    Dymińska, Lucyna

    2015-09-15

    Derivatives of imidazopyridine are used in medicinal chemistry due to their biological and pharmaceutical properties. This review article presents imidazopyridine pharmacological activity as antiinflammatory, anticancer, antiviral, antiosteoporotic, antiparasitic, and antihypertensive agents by studying its various synthesized derivatives. Some of compounds with imidazopyridine skeleton are used in psychiatry and autoimmune disorders. The presented data suggest that IR and Raman spectra measurements are a good methods for identification and characterization of the compounds containing imidazopyridine core. Two stretching vibrations: νas(Φ) and νs(Φ) are of a diagnostic importance. The appearance of these bands in the IR and Raman spectra of some plants, tissues and pharmaceuticals confirms the presence of imidazopyridine skeleton in these substances. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Investigation of the optical properties of MoS{sub 2} thin films using spectroscopic ellipsometry

    Energy Technology Data Exchange (ETDEWEB)

    Yim, Chanyoung; O' Brien, Maria; Winters, Sinéad [School of Chemistry, Trinity College Dublin, Dublin 2 (Ireland); Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2 (Ireland); McEvoy, Niall [Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2 (Ireland); Mirza, Inam; Lunney, James G. [Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2 (Ireland); School of Physics, Trinity College Dublin, Dublin 2 (Ireland); Duesberg, Georg S., E-mail: duesberg@tcd.ie [School of Chemistry, Trinity College Dublin, Dublin 2 (Ireland); Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2 (Ireland); Advanced Materials and BioEngineering Research (AMBER) Centre, Trinity College Dublin, Dublin 2 (Ireland)

    2014-03-10

    Spectroscopic ellipsometry (SE) characterization of layered transition metal dichalcogenide (TMD) thin films grown by vapor phase sulfurization is reported. By developing an optical dispersion model, the extinction coefficient and refractive index, as well as the thickness of molybdenum disulfide (MoS{sub 2}) films, were extracted. In addition, the optical band gap was obtained from SE and showed a clear dependence on the MoS{sub 2} film thickness, with thinner films having a larger band gap energy. These results are consistent with theory and observations made on MoS{sub 2} flakes prepared by exfoliation, showing the viability of vapor phase derived TMDs for optical applications.

  3. Investigation of the optical properties of MoS2 thin films using spectroscopic ellipsometry

    International Nuclear Information System (INIS)

    Yim, Chanyoung; O'Brien, Maria; Winters, Sinéad; McEvoy, Niall; Mirza, Inam; Lunney, James G.; Duesberg, Georg S.

    2014-01-01

    Spectroscopic ellipsometry (SE) characterization of layered transition metal dichalcogenide (TMD) thin films grown by vapor phase sulfurization is reported. By developing an optical dispersion model, the extinction coefficient and refractive index, as well as the thickness of molybdenum disulfide (MoS 2 ) films, were extracted. In addition, the optical band gap was obtained from SE and showed a clear dependence on the MoS 2 film thickness, with thinner films having a larger band gap energy. These results are consistent with theory and observations made on MoS 2 flakes prepared by exfoliation, showing the viability of vapor phase derived TMDs for optical applications

  4. A spectroscopic and catalytic investigation of active phase-support interactions

    Energy Technology Data Exchange (ETDEWEB)

    Haller, G.L.

    1991-01-01

    Active catalytic phases (metal, mixed metals, oxide or mixed oxides) interacting with oxide support on which the active phase is dispersed can affect the percentage exposed, the morphology of supported particles, the degree of reducibility of cations, etc., in a variety of ways. Our objective is to characterize the physical chemistry of the active phase-oxide support by spectroscopic methods and to correlate this structure with catalytic function. The three systems discussed in this progress report are Ag/TiO{sub 2}, Ru-Cu/SiO{sub 2} and SiO{sub 2}/Al{sub 2}O{sub 3}. 24 refs., 3 figs., 2 tabs.

  5. Combined raman/laser-induced breakdown spectrometer: space and non-space applications

    NARCIS (Netherlands)

    Sandtke, M.; Laan, E.C.; Ahlers, B.

    2010-01-01

    TNO has developed the combination of two spectroscopic analysis methods in one instrument. Raman spectroscopy and Laser-induced Breakdown Spectroscopy (LIBS) were brought together for an instrument to be flown on the ExoMars mission from the European Space Agency (ESA) to investigate the Martian

  6. On the Increasing Fragility of Human Teeth with Age: ADeep-Ultraviolet Resonance Raman Study

    Energy Technology Data Exchange (ETDEWEB)

    Ager III, J.W.; Nalla, R.K.; Balooch, G.; Kim, G.; Pugach, M.; Habelitz, S.; Marshall, G.W.; Kinney, J.H.; Ritchie, R.O.

    2006-07-14

    Ultraviolet resonance Raman spectroscopy (UVRRS) using 244nm excitation was used to investigate the impact of aging on humandentin. The intensity of a spectroscopic feature from the peptide bondsin the collagen increases with tissue age, similar to a finding reportedpreviously for human cortical bone.

  7. Raman spectroscopic determination of the length, strength, compressibility, Debye temperature, elasticity, and force constant of the C-C bond in graphene.

    Science.gov (United States)

    Yang, X X; Li, J W; Zhou, Z F; Wang, Y; Yang, L W; Zheng, W T; Sun, Chang Q

    2012-01-21

    From the perspective of bond relaxation and bond vibration, we have formulated the Raman phonon relaxation of graphene, under the stimuli of the number-of-layers, the uni-axial strain, the pressure, and the temperature, in terms of the response of the length and strength of the representative bond of the entire specimen to the applied stimuli. Theoretical unification of the measurements clarifies that: (i) the opposite trends of the Raman shifts, which are due to the number-of-layers reduction, of the G-peak shift and arises from the vibration of a pair of atoms, while the D- and the 2D-peak shifts involve the z-neighbor of a specific atom; (ii) the tensile strain-induced phonon softening and phonon-band splitting arise from the asymmetric response of the C(3v) bond geometry to the C(2v) uni-axial bond elongation; (iii) the thermal softening of the phonons originates from bond expansion and weakening; and (iv) the pressure stiffening of the phonons results from bond compression and work hardening. Reproduction of the measurements has led to quantitative information about the referential frequencies from which the Raman frequencies shift as well as the length, energy, force constant, Debye temperature, compressibility and elastic modulus of the C-C bond in graphene, which is of instrumental importance in the understanding of the unusual behavior of graphene.

  8. Raman spectroscopic analysis of dragon's blood resins-basis for distinguishing between Dracaena(Convallariaceae), Daemonorops(Palmae) and Croton(Euphorbiaceae).

    Science.gov (United States)

    Edwards, Howell G M; de Oliveira, Luiz F C; Prendergast, Hew D V

    2004-02-01

    "Dragon[prime or minute]s blood" is the name applied to the deep-red coloured resin obtained from various plants. The original source in Roman times, used by many cultures and esteemed for its depth of colour and mystical association, was the dragon tree Dracaena cinnabari(Convallariaceae), found only on the Indian Ocean island of Socotra, (Yemen). Additional sources emerged later, including another species of Dracaena, D. draco, from the Canary Islands and Madeira, and species in the genera Daemonorops(Palmae) from South East Asia and Croton(Euphorbiaceae) from tropical parts of both the New and Old Worlds. In this study, examples of dragon's blood resins from the Economic Botany Collections at the Royal Botanic Gardens, Kew, dating from 1851 to 1993, have been analysed non-destructively using Raman spectroscopy. The Raman spectra of well-documented, provenanced specimens have been used to establish the source of specimens of questionable or unknown origin. It has also been possible from the Raman spectra to indicate whether processing of the resins has been undertaken in the preparation of the specimens before their deposition at Kew.

  9. Infrared and Raman spectroscopic studies of interlayer CO32-, NO3-, SO42- and ClO4-in layered double hydroxides (LDHs)

    International Nuclear Information System (INIS)

    Kloprogge, J.T.; Wharton, D.; Frost, R.L.

    1998-01-01

    Full text: Hydrotalcites (HTs) are also described as layered double hydroxides or anionic clays, due to their layered structure with a charge opposite to that of cationic clays. The number of counterbalancing anions or anionic complexes is essentially unlimited provided that the anion does not form a complex with the cations in the octahedral sheets during the formation. The majority of especially the synthetic but also naturally occurring HTs contain CO 3 2- as the interlayer anion. Other regularly used anions include NO 3 - , OH - , SO 4 2- and Cl - in addition to ClO 4 - and CrO 4 2- . When CO 3 2- is present as a free ion it will exhibit a space group of D 3h . As a result the bending non-planar mode ν 2 (A'2), the antisymmetrical stretching mode ν 3 (E') and the bending angular mode ν 4 (E'), will be observed in the IR spectrum at 880, 1415 and 680 cm -1 , while the symmetric stretching mode ν 1 (A'1) is IR inactive. In the Raman spectrum one will observe ν 1 (A'1), ν 3 (E') and ν 4 (E') (Nakamoto, 1997; Farmer, 1974). In comparison to free CO 3 2- a shift towards lower wavenumbers is generally observed. A band around 3000-3100 cm -1 has been attributed to the bridging mode H 2 O-CO 3 2- . The shift towards lower wavenumbers indicates a lowering of the symmetry from D 3h , to probably C 2s or C ν . As a result the IR inactive ν 1 mode will be activated. Indeed, a weak band has been observed around 1050-1060 cm -1 . In addition, the ν 3 mode shows a small splitting in the order of 30-60 cm -1 . In accordance to the findings of Moroz and Arkhipenko (1991), Kloprogge and Frost (1999) and Hickey et al. (2000) observed weak Raman ν 3 and νv 4 modes at 1053 and 1403 cm -1 . Like in the IR spectra, both ν 3 and νv 4 show a minor shift of 10 to 15 cm -1 . Like free CO 3 2- free nitrate NO 3 - will exhibit a spacegroup of D 3h with A 1 ' Raman actively only, A 2 '' IR active only and 2E' Raman and IR active. This means that the out-of-plane symmetric

  10. Quantum mechanical, spectroscopic studies (FT-IR, FT-Raman, NMR, UV) and normal coordinates analysis on 3-([2-(diaminomethyleneamino) thiazol-4-yl] methylthio)-N'-sulfamoylpropanimidamide

    Science.gov (United States)

    Muthu, S.; Uma Maheswari, J.; Sundius, Tom

    2013-05-01

    Famotidine (3-([2-(diaminomethyleneamino) thiazol-4-yl] methylthio)-N'-sulfamoylpropanimidamide) is a histamine H2-receptor antagonist that inhibits stomach acid production, and it is commonly used in the treatment of peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD/GORD). Quantum chemical calculations of the equilibrium geometry of famotidine in the ground state were carried out using density functional theory (DFT/B3LYP) with the 6-311G(d,p) basis set. In addition, harmonic vibrational frequencies, infrared intensities and Raman activities were calculated at the same level of theory. A detailed interpretation of the infrared and Raman spectrum of the drug is also reported. Theoretical simulations of the FT-IR, and FT-Raman spectra of the title compound have been calculated. Good correlations between the experimental 1H and 13C NMR chemical shifts and calculated GIAO shielding tensors were found. The results of the energy and oscillator strength calculations by time-dependent density functional theory (TD-DFT) supplement the experimental findings. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (COOP or OPDOS) diagrams analysis were presented. The dipole moment, linear polarizability and first order hyperpolarizability values were also computed. The linear polarizability and first order hyperpolarizabilities of the studied molecule indicate that the compound is a good candidate for nonlinear optical materials.

  11. Direct visual evidence of end-on adsorption geometry of pyridine on silver surface investigated by surface enhanced Raman scattering and density functional theory calculations.

    Science.gov (United States)

    Bhunia, Snehasis; Forster, Stefan; Vyas, Nidhi; Schmitt, Hans-Christian; Ojha, Animesh K

    2015-12-05

    Fourier transform Raman (FT-Raman) spectra of neat pyridine (Py) and surface enhanced Raman scattering (SERS) spectra of Py with silver nanoparticles (AgNPs) solution at different molar concentrations (X=1.5M, 1.0M, 0.50 M, 0.25 M, and 0.125 M) were recorded using 1064 nm excitation wavelength. The intensity of Raman bands at ∼1003 (ν11) and ∼1035 (ν21) cm(-1) of Py is enhanced in the SERS spectra. Two new Raman bands were observed at ∼1009 (ν12) and ∼1038 (ν22) cm(-1) in the SERS spectra. These bands correspond to the ring breathing vibrations of Py molecules adsorbed at the AgNPs surface. The value of intensity ratios (I12/I11) and (I21/I22) is increased with dilution and attains a maximum value at X=0.5M and upon further dilution (0.25 and 0.125 M) it drops gradually. The theoretically calculated Raman spectra were found to be in good agreement with experimentally observed Raman spectra. Both, experimental and theoretical investigations have confirmed that the Py interacts with AgNPs via the end-on geometry. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. [Application of Raman spectroscopy to investigation of CVD-SIC fiber].

    Science.gov (United States)

    Liu, Bin; Yang, Yan-Qing; Luo, Xian; Huang, Bin

    2011-11-01

    The CVD-SiC fiber was studied by using laser Raman spectra. It was found that the sharp TO peak exists in the first SiC deposit layer, indicating the larger SiC grains. But the second SiC deposit layer is with small grains. Raman peak of carbon and silicon was detected respectively in the first and second layer. Compared with that of the single SiC fiber, the TO peaks move to the high wave number for the SiC fiber in SiC(f)/Ti-6Al-4V composite. It indicates that the compressive thermal residual stress is present in the SiC fiber during the fabrication of the composite because of the mismatched coefficient of thermal expansion between Ti-6Al-4V matrix and SiC fiber. The average thermal residual stress of the SiC fiber in SiC(f)/Ti-6Al-4V composite was calculated to be 318 MPa and the residual stress in first deposit layer is 436 MPa which is much higher than that in the second layer.

  13. FTIR, FT-Raman, FT-NMR and quantum chemical investigations of 3-acetylcoumarin.

    Science.gov (United States)

    Arjunan, V; Sakiladevi, S; Marchewka, M K; Mohan, S

    2013-05-15

    3-Acetylcoumarin (3AC) was synthesised by a Knoevenagel reaction. Conformational analysis using the B3LYP method was also carried out to determine the most stable conformation of the compound. FTIR and FT-Raman spectra of 3AC have been recorded in the range 4000-400 and 4000-100 cm(-1), respectively. (1)H and (13)C NMR spectra have also been recorded. The complete vibrational assignment and analysis of the fundamental modes of the compound were carried out using the experimental FTIR and FT-Raman data and quantum mechanical studies. The experimental vibrational frequencies were compared with the wavenumbers obtained theoretically from the DFT-B3LYP/B3PW91 gradient calculations employing the standard 6-31G(**), high level 6-311++G(**) and cc-pVTZ basis sets for optimised geometry of the compound. The frontier molecular orbital energies of the compound are determined by DFT method. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. A Spectroscopic and Electrochemical Investigation of Interactions of Anticancer Uracil Derivatives with Cationic and Anionic Surfactants

    International Nuclear Information System (INIS)

    Zafar, F.; Shah, A.; Ahmad, Z.; Siddiq, M.; Ali, S.; Asad Muhammad Khan, A. M.; Rana, U. A.

    2015-01-01

    Interactions of 5-fluorouracil (5-FU), a commercially available anti-cancer drug and two other possibly anti-cancer actives, 2-thiouracil (2-TU) and 2,4-dithiouracil (DTU), with anionic sodium dodecyl sulphate (SDS) and cationic cetlytrimethyl ammonium bromide (CTAB) surfactants were studied using cyclic voltammetry and UV-Visible spectroscopic techniques. The results from both techniques asserted the formation of complex between the drugs and surfactants. In the pre-micellar concentrations, the binding was mainly due to the interactions between the surfactants monomers (electrostatic) and the drug molecules, while in the post-micellar region, drug was encapsulated within the micelle due to electrostatic as well as hydrophobic interactions. The UV-Visible spectroscopic data of the interaction between 5-fluorouracil and the surfactants exhibited an isobestic point which indicated the presence of equilibrium species in bulk and the micellar phase. Binding constant, partition coefficient between bulk and miceller phase, and the number of drug molecules incorporated per micelle were calculated. (author)

  15. Argon plasma jet continuum emission investigation by using different spectroscopic methods

    International Nuclear Information System (INIS)

    Dgheim, J

    2007-01-01

    Radiation and temperature fields of the continuum field are determined by using different spectroscopic methods based on the spectral emission of an argon plasma jet. An interferential filter of bandwidth 2.714 nm centred at a wavelength of 633 nm is used to observe only the continuum emission and to eliminate the self-absorption phenomenon. An optical multichannel analyser (OMA) of an MOS detector is used to measure argon plasma jet volumetric emissivity under atmospheric pressure and high temperatures. An emission spectroscopic method is used to measure the Stark broadening of the hydrogen line H β and to determine the electron density. The local thermodynamic equilibrium is established and its limit is stated. The local electron temperature is determined by two methods (the continuum emission relation and the LTE relations), and the total Biberman factor is measured. The results given by the OMA are compared with those given by the imagery method. At a given wavelength, the Biberman factor, which depends on the electron temperature and the electron density, may serve as an indicator to show where the LTE prevails along the argon plasma jet core length

  16. Spectroscopic investigation of the wettability of multilayer graphene using highly ordered pyrolytic graphite as a model material.

    Science.gov (United States)

    Ashraf, Ali; Wu, Yanbin; Wang, Michael C; Aluru, Narayana R; Dastgheib, Seyed A; Nam, SungWoo

    2014-11-04

    We report the intrinsic water contact angle (WCA) of multilayer graphene, explore different methods of cleaning multilayer graphene, and evaluate the efficiency of those methods on the basis of spectroscopic analysis. Highly ordered pyrolytic graphite (HOPG) was used as a model material system to study the wettability of the multilayer graphene surface by WCA measurements. A WCA value of 45° ± 3° was measured for a clean HOPG surface, which can serve as the intrinsic WCA for multilayer graphene. A 1 min plasma treatment (100 W) decreased the WCA to 6°, owing to the creation of surface defects and functionalization by oxygen-containing groups. Molecular dynamics simulations of water droplets on the HOPG surface with or without the oxygen-containing defect sites confirmed the experimental results. Heat treatment at near atmospheric pressure and wet chemical cleaning methods using hydrofluoric acid and chloroform did not change the WCA significantly. Low-pressure, high-temperature annealing under argon and hydrogen reduced the WCA to 54°, close to the intrinsic WCA of HOPG. Raman spectroscopy and atomic force microscopy did not show any significant change for the HOPG surface after this treatment, confirming low-pressure, high-temperature annealing as an effective technique to clean multilayer graphene without damaging the surface. Time-of-flight secondary ion mass spectrometry indicated the existence of hydrocarbon species on the surface of the HOPG sample that was exposed to air for <5 min and the absence of these impurities in the bulk. X-ray photoelectron spectroscopy analyses of the sample surfaces after the different cleaning techniques were performed to correlate the WCA to the surface chemistry. X-ray photoelectron spectroscopy results revealed that the WCA value changed drastically, depending on the amounts of oxygen-containing and hydrocarbon-containing groups on the surface.

  17. UV-VIS-spectroscopical investigations of the green solutions of nitrogen triiodide-1-pyridine in pyridine

    International Nuclear Information System (INIS)

    Kerbachi, R.; Minkwitz, R.; Engelhardt, U.

    1984-01-01

    Solid, crystalline nitrogen triiodide-1-pyridine has a polymeric structure similar to that of nitrogen triiodide-1-ammonia consisting of NI 4 tetrahedra linked to chains by common vertices. The solubility of both compounds in liquid ammonia is accomplished by a degradation of the chains involving protolysis equilibria with monoiodamine. UV-VIS-spectra of the green solutions of NI 3 pyridine in the aprotic solvent pyridine between -30 and -16 0 C and Raman-spectra of these solutions at -30 0 C or quenched with liquid nitrogen at -196 0 C show, that the chains are retained here at least to some extent. The solutions are instable even at low temperatures and decompose in a first order reaction yielding nitrogen and iodine. The halflife period at -16 0 C is 5 hours, at -30 0 C 20 hours. (author)

  18. DFT simulation, quantum chemical electronic structure, spectroscopic and structure-activity investigations of 2-benzothiazole acetonitrile.

    Science.gov (United States)

    Arjunan, V; Thillai Govindaraja, S; Jose, Sujin P; Mohan, S

    2014-07-15

    The Fourier transform infrared and FT-Raman spectra of 2-benzothiazole acetonitrile (BTAN) have been recorded in the range 4000-450 and 4000-100 cm(-1) respectively. The conformational analysis of the compound has been carried out to obtain the stable geometry of the compound. The complete vibrational assignment and analysis of the fundamental modes of the compound are carried out using the experimental FTIR and FT-Raman data and quantum chemical studies. The experimental vibrational frequencies are compared with the wavenumbers derived theoretically by B3LYP gradient calculations employing the standard 6-31G(**), high level 6-311++G(**) and cc-pVTZ basis sets. The structural parameters, thermodynamic properties and vibrational frequencies of the normal modes obtained from the B3LYP methods are in good agreement with the experimental data. The (1)H (400 MHz; CDCl3) and (13)C (100 MHz;CDCl3) nuclear magnetic resonance (NMR) spectra are also recorded. The electronic properties, the energies of the highest occupied and lowest unoccupied molecular orbitals are measured by DFT approach. The kinetic stability of the molecule has been determined from the frontier molecular orbital energy gap. The charges of the atoms and the structure-chemical reactivity relations of the compound are determined by its chemical potential, global hardness, global softness, electronegativity, electrophilicity and local reactivity descriptors by conceptual DFT methods. The non-linear optical properties of the compound have been discussed by measuring the polarisability and hyperpolarisability tensors. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Investigation of melt structure and crystallization processes by high-temperature Raman spectroscopy method

    International Nuclear Information System (INIS)

    Voron'ko, Yu.K.; Kudryavtsev, A.B.; Osiko, V.V.; Sobol', A.A.

    1988-01-01

    A review of studies dealing with the melts of alkali, rare earth and other element phosphates, gallates, germanates, niobates and tungstates, which are carried out by the method of high-temperature Raman spectroscopy, is given. The effect of the melt structure on the mechanism of the substance cystallization is considered. It is shown that vitrification and supercooling of the melt, as well as its crystallization in the from of metastable structures, are related to the effect of nonconformity between the melt and crystal strucure. The effect of nonconformity between anion motives in the melt and crystal creates obstacles for equilibrium structure nucleation, which results in the formation mainly of metastable forms with lattice structure for from the structure of the melt, though cases of equilibrium phase crystallization are also possible. 37 refs.; 13 figs.; 2 tabs

  20. Determination of Sudan I in paprika powder by molecularly imprinted polymers-thin layer chromatography-surface enhanced Raman spectroscopic biosensor.

    Science.gov (United States)

    Gao, Fang; Hu, Yaxi; Chen, Da; Li-Chan, Eunice C Y; Grant, Edward; Lu, Xiaonan

    2015-10-01

    Sudan I is a carcinogenic and mutagenic azo-compound that has been utilized as a common adulterant in spice and spice blends to impart a desirable red color to foods. A novel biosensor combining molecularly imprinted polymers (MIPs), thin layer chromatography (TLC) and surface enhanced Raman spectroscopy (SERS) could determine Sudan I levels in paprika powder to 1 ppm (or 2 ng/spot). Sudan I spiked paprika extracts (spiking levels: 0, 1, 5, 10, 40, 70 and 100 ppm) were prepared. Sudan I imprinted polymers were synthesized by employing the interaction between Sudan I (template) and methacrylic acid (functional monomer), followed by washing to remove Sudan I leaving the Sudan I-binding sites exposed. MIPs were used as a stationary phase for TLC and could selectively retain Sudan I at the original spot with little interference. A gold colloid SERS substrate could enhance Raman intensity for Sudan I in this MIP-TLC system. Principal component analysis plot and partial least squares regression (R(2)=0.978) models were constructed and a linear regression model (R(2)=0.983) correlated spiking levels (5, 10, 40, 70 and 100 ppm) with the peak intensities (721 cm(-1)) of Sudan I SERS spectra. Both separation (30-40s) and detection (1s or 0.1s) were extremely fast by using both commercial bench-top and custom made portable Raman spectrometers. This biosensor can be applied as a rapid, low-cost and reliable tool for screening Sudan I adulteration in foods. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Theoretical Investigation of OCN(-) Charge Transfer Complexes in Condensed Phase Media: Spectroscopic Properties in Amorphous Ice

    Science.gov (United States)

    Park, Jin-Young; Woon, David E.

    2004-01-01

    Density functional theory (DFT) calculations of cyanate (OCN(-)) charge-transfer complexes were performed to model the "XCN" feature observed in interstellar icy grain mantles. OCN(-) charge-transfer complexes were formed from precursor combinations of HNCO or HOCN with either NH3 or H2O. Three different solvation strategies for realistically modeling the ice matrix environment were explored, including (1) continuum solvation, (2) pure DFT cluster calculations, and (3) an ONIOM DFT/PM3 cluster calculation. The model complexes were evaluated by their ability to reproduce seven spectroscopic measurements associated with XCN: the band origin of the OCN(-) asymmetric stretching mode, shifts in that frequency due to isotopic substitutions of C, N, O, and H, plus two weak features. The continuum solvent field method produced results consistent with some of the experimental data but failed to account for other behavior due to its limited capacity to describe molecular interactions with solvent. DFT cluster calculations successfully reproduced the available spectroscopic measurements very well. In particular, the deuterium shift showed excellent agreement in complexes where OCN(-) was fully solvated. Detailed studies of representative complexes including from two to twelve water molecules allowed the exploration of various possible solvation structures and provided insights into solvation trends. Moreover, complexes arising from cyanic or isocyanic acid in pure water suggested an alternative mechanism for the formation of OCN(-) charge-transfer complexes without the need for a strong base such as NH3 to be present. An extended ONIOM (B3LYP/PM3) cluster calculation was also performed to assess the impact of a more realistic environment on HNCO dissociation in pure water.

  2. A new look into the quantum chemical and spectroscopic investigations of 5-chloro-1-methyl-4-nitroimidazole.

    Science.gov (United States)

    Arjunan, V; Raj, Arushma; Anitha, R; Mohan, S

    2014-05-05

    Optimised geometrical structural parameters, harmonic vibrational frequencies, natural bonding orbital analysis and frontier molecular orbitals are determined by B3LYP and B3PW91 methods. The exact geometry of 5-chloro-1-methyl-4-nitroimidazole is determined through conformational analysis. The experimentally observed infrared and Raman bands have been assigned and analysed. The (13)C and (1)H NMR chemical shifts of the compound are investigated. The total electron density and molecular electrostatic potentials are determined. The electrostatic potential (electron+nuclei) distribution, molecular shape, size and dipole moments of the molecule have been displayed. The energies of the frontier molecular orbitals and LUMO-HOMO energy gap are measured. The possible electronic transitions of the molecule are studied by TD-DFT method along with the UV-Visible spectrum. The structure-activity relationship of the compound is also investigated by conceptual DFT methods. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Structural Changes Induced in Grapevine (Vitis vinifera L. DNA by Femtosecond IR Laser Pulses: A Surface-Enhanced Raman Spectroscopic Study

    Directory of Open Access Journals (Sweden)

    Nicoleta E. Dina

    2016-05-01

    Full Text Available In this work, surface-enhanced Raman spectra of ten genomic DNAs extracted from leaf tissues of different grapevine (Vitis vinifera L. varieties, respectively, are analyzed in the wavenumber range 300–1800 cm−1. Furthermore, structural changes induced in grapevine genomic nucleic acids upon femtosecond (170 fs infrared (IR laser pulse irradiation (λ = 1100 nm are discussed in detail for seven genomic DNAs, respectively. Surface-enhanced Raman spectroscopy (SERS signatures, vibrational band assignments and structural characterization of genomic DNAs are reported for each case. As a general observation, the wavenumber range between 1500 and 1660 cm−1 of the spectra seems to be modified upon laser treatment. This finding could reflect changes in the base-stacking interactions in DNA. Spectral shifts are mainly attributed to purines (dA, dG and deoxyribose. Pyrimidine residues seem to be less affected by IR femtosecond laser pulse irradiation. Furthermore, changes in the conformational properties of nucleic acid segments are observed after laser treatment. We have found that DNA isolated from Feteasca Neagra grapevine leaf tissues is the most structurally-responsive system to the femtosecond IR laser irradiation process. In addition, using unbiased computational resources by means of principal component analysis (PCA, eight different grapevine varieties were discriminated.

  4. The spectroscopic (FT-IR, FT-Raman, UV and NMR) first order hyperpolarizability and HOMO-LUMO analysis of dansyl chloride

    Science.gov (United States)

    Karabacak, M.; Cinar, M.; Kurt, M.; Poiyamozhi, A.; Sundaraganesan, N.

    2014-01-01

    The solid phase FT-IR and FT-Raman spectra of dansyl chloride (DC) have been recorded in the regions 400-4000 and 50-4000 cm-1, respectively. The spectra have been interpreted in terms of fundamentals modes, combination and overtone bands. The structure of the molecule has been optimized and the structural characteristics have been determined by density functional theory (B3LYP) method with 6-311++G(d,p) as basis set. The vibrational frequencies were calculated for most stable conformer and were compared with the experimental frequencies, which yield good agreement between observed and calculated frequencies. The infrared and Raman spectra have also been predicted from the calculated intensities. 1H and 13C NMR spectra were recorded and 1H and 13C nuclear magnetic resonance chemical shifts of the molecule were calculated using the gauge independent atomic orbital (GIAO) method. UV-Visible spectrum of the compound was recorded in the region 200-600 nm and the electronic properties HOMO and LUMO energies were measured by time-dependent TD-DFT approach. Nonlinear optical and thermodynamic properties were interpreted. All the calculated results were compared with the available experimental data of the title molecule.

  5. DFT-assisted spectroscopic characterization of pyrazosulfuron-ethyl: FT-Raman, FTIR and UV-vis studies of a sulfonyl urea herbicide

    Science.gov (United States)

    Monicka, J. Clemy; James, C.

    2014-10-01

    Raman and IR spectra of pyrazosulfuron-ethyl have been reported here, and it is shown that the spectra has been fully interpreted in terms of assigning normal modes to the various spectral features by using density functional theory calculations. The Raman bands observed for PY in solid phase are characteristic for the carbonyl group, Csbnd C, Csbnd H and Nsbnd H stretching and deformation vibrations. The dimer structure of PY was optimized, including the Nsbnd H…N and Csbnd H…O intermolecular interactions. Stability of the molecule arising from hyperconjugative interactions leading to its bioactivity and charge delocalization have been analyzed using natural bond orbital analysis. Spectral analysis reveals the substantial effect of non-bonding interaction, conjugation and induction effects in the molecule which in turn influences the bioactivity of the compound. Red shifting of (∼94 cm-1) Nsbnd H stretching band substantiates the presence of strong Nsbnd H…N intramolecular hydrogen bonding in the molecule. The aromatic behavior of pyrimidine and pyrazole ring has been calculated using the HOMA method.

  6. A grid matrix-based Raman spectroscopic method to characterize different cell milieu in biopsied axillary sentinel lymph nodes of breast cancer patients.

    Science.gov (United States)

    Som, Dipasree; Tak, Megha; Setia, Mohit; Patil, Asawari; Sengupta, Amit; Chilakapati, C Murali Krishna; Srivastava, Anurag; Parmar, Vani; Nair, Nita; Sarin, Rajiv; Badwe, R

    2016-01-01

    Raman spectroscopy which is based upon inelastic scattering of photons has a potential to emerge as a noninvasive bedside in vivo or ex vivo molecular diagnostic tool. There is a need to improve the sensitivity and predictability of Raman spectroscopy. We developed a grid matrix-based tissue mapping protocol to acquire cellular-specific spectra that also involved digital microscopy for localizing malignant and lymphocytic cells in sentinel lymph node biopsy sample. Biosignals acquired from specific cellular milieu were subjected to an advanced supervised analytical method, i.e., cross-correlation and peak-to-peak ratio in addition to PCA and PC-LDA. We observed decreased spectral intensity as well as shift in the spectral peaks of amides and lipid bands in the completely metastatic (cancer cells) lymph nodes with high cellular density. Spectral library of normal lymphocytes and metastatic cancer cells created using the cellular specific mapping technique can be utilized to create an automated smart diagnostic tool for bench side screening of sampled lymph nodes. Spectral library of normal lymphocytes and metastatic cancer cells created using the cellular specific mapping technique can be utilized to develop an automated smart diagnostic tool for bench side screening of sampled lymph nodes supported by ongoing global research in developing better technology and signal and big data processing algorithms.

  7. Effects of laser photherapy on bone defects grafted with mineral trioxide aggregate, bone morphogenetic proteins, and guided bone regeneration: a Raman spectroscopic study.

    Science.gov (United States)

    Pinheiro, Antonio L B; Aciole, Gilberth T S; Cangussú, Maria Cristina T; Pacheco, Marcos T T; Silveira, Landulfo

    2010-12-15

    We have used Raman analysis to assess bone healing on different models. Benefits on the isolated or combined use of mineral trioxide aggregate, bone morphogenetic proteins, guided bone regeneration and laser on bone repair have been reported, but not their combination. We studied peaks of hydroxyapatite and CH groups on defects grafted with MTA, treated or not with laser, BMPs, and GBR. Ninety rats were divided in 10 groups each, subdivided into three subgroups. Laser (λ850 nm) was applied at every other day for 2 weeks. Raman readings were taken at the surface of the defect. Statistical analysis (CHA) showed significant differences between all groups (p = 0.001) and between Group II and all other (p hydroxyapatite (CHA) that is indicative of greater calcification and resistance of the bone. We conclude that the association of the MTA with laser phototherapy (LPT) and/or not with GBR resulted in a better bone repair. The use of the MTA associated to IR LPT resulted in a more advanced and quality bone repair. Copyright © 2010 Wiley Periodicals, Inc.

  8. Effects of LED phototherapy on bone defects grafted with MTA, bone morphogenetic proteins and guided bone regeneration: a Raman spectroscopic study.

    Science.gov (United States)

    Pinheiro, Antonio L B; Soares, Luiz G P; Cangussú, Maria Cristina T; Santos, Nicole R S; Barbosa, Artur Felipe S; Silveira Júnior, Landulfo

    2012-09-01

    We studied peaks of calcium hydroxyapatite (CHA) and protein and lipid CH groups in defects grafted with mineral trioxide aggregate (MTA) treated or not with LED irradiation, bone morphogenetic proteins and guided bone regeneration. A total of 90 rats were divided into ten groups each of which was subdivided into three subgroups (evaluated at 15, 21 and 30 days after surgery). Defects were irradiated with LED light (wavelength 850 ± 10 nm) at 48-h intervals for 15 days. Raman readings were taken at the surface of the defects. There were no statistically significant differences in the CHA peaks among the nonirradiated defects at any of the experimental time-points. On the other hand, there were significant differences between the defects filled with blood clot and the irradiated defects at all time-points (p Raman spectral analysis indicate that infrared LED light irradiation improves the deposition of CHA in healing bone grafted or not with MTA.

  9. Raman Spectroscopy and Electrochemical Investigations of Pt Electrocatalyst Supported on Carbon Prepared through Plasma Pyrolysis of Natural Gas

    Directory of Open Access Journals (Sweden)

    Tereza Cristina Santos Evangelista

    2015-01-01

    Full Text Available Physicochemical and electrochemical characterisations of Pt-based electrocatalysts supported on carbon (Vulcan carbon, C1, and carbon produced by plasma pyrolysis of natural gas, C2 toward ethanol electrooxidation were investigated. The Pt20/C180 and Pt20/C280 electrocatalysts were prepared by thermal decomposition of polymeric precursors at 350°C. The electrochemical and physicochemical characterisations of the electrocatalysts were performed by means of X-ray diffraction (XRD, transmission electron microscope (TEM, Raman scattering, cyclic voltammetry, and chronoamperometry tests. The XRD results show that the Pt-based electrocatalysts present platinum metallic which is face-centered cubic structure. The results indicate that the Pt20/C180 electrocatalyst has a smaller particle size (10.1–6.9 nm compared with the Pt20/C280 electrocatalyst; however, the Pt20/C280 particle sizes are similar (12.8–10.4 nm and almost independent of the reflection planes, which suggests that the Pt crystallites grow with a radial shape. Raman results reveal that both Vulcan carbon and plasma carbon are graphite-like materials consisting mostly of sp2 carbon. Cyclic voltammetry and chronoamperometry data obtained in this study indicate that the deposition of Pt on plasma carbon increases its electrocatalytic activity toward ethanol oxidation reaction.

  10. Thermal, mechanical and Raman studies on mixed alkali borotungstate glasses

    Science.gov (United States)

    Edukondalu, A.; Sathe, Vasant; Rahman, Syed; Siva Kumar, K.

    2014-04-01

    Mixed alkali borotungstate glasses with xLi2O-(30-x)Na2O-10WO3-60B2O3 (0 ≤ x ≤ 30) composition were prepared by melt quench technique. The amorphous phase of the prepared glass samples was conformed from their X-ray diffraction and SEM studies. Differential scanning calorimetry and Raman spectroscopic studies were employed to investigate the structure of all the prepared glasses. The elastic moduli and Debye temperature were calculated in terms of Makishima-Mackenzie model. Acting as complementary techniques, Raman measurement revealed that the network structure of the present glasses is mainly based on BO3 and BO4 units placed in different structural groups. Raman spectra confirms the presence of tungsten ions mainly as WO6 groups. In the present work, the mixed alkali effect (MAE) has been investigated in the above glass system through modulated DSC studies.

  11. Thermal, structural and spectroscopic investigations on Eu{sup 3+} doped boro-tellurite glasses

    Energy Technology Data Exchange (ETDEWEB)

    Selvaraju, K. [Department of Physics, Gandhigram Rural University, Gandhigram 624 302 (India); Marimuthu, K., E-mail: mari_ram2000@yahoo.com [Department of Physics, Gandhigram Rural University, Gandhigram 624 302 (India); Seshagiri, T.K.; Godbole, S.V. [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Fundamental O-H, (BO{sub 3}){sup -} vibrations and B-O-B linkages in borate network explored. Black-Right-Pointing-Pointer The covalent nature of the Eu{sup 3+} ions with surrounding ligands have been confirmed. Black-Right-Pointing-Pointer B3TMK glass is found to be the best optical candidate for laser working at 612 nm. - Abstract: Eu{sup 3+} doped boro-tellurite glasses with the chemical composition (69 - x)B{sub 2}O{sub 3}-xTeO{sub 2}-15Mg{sub 2}O-15K{sub 2}O-1Eu{sub 2}O{sub 3} (where x = 0, 10, 20, 30 and 40 wt%) have been synthesized and its thermal, structural and spectroscopic behavior were studied and reported. The thermal behavior of the Eu{sup 3+} doped boro-tellurite glasses were explored through DTA thermograms. The presence of varying tellurium dioxide results in structural and spectroscopic changes around Eu{sup 3+} ions and are explored through XRD, FTIR, UV-vis, Luminescence and lifetime measurements. The XRD pattern confirms the amorphous nature and the FTIR spectra reveal the formation of the local structural units BO{sub 3} and BO{sub 4} in the prepared glasses. The bonding parameters (-bar {beta} and {delta}) have been calculated based on the observed band positions of the absorption spectra. The Judd-Ofelt (JO) parameters were determined from the absorption and luminescence spectra and the results are presented. The variation in the JO intensity parameters {Omega}{sub {lambda}} ({lambda} = 2, 4 and 6) and the hypersensitive band positions with the change in chemical composition have been discussed in detail. The JO parameters have been used to derive important radiative properties like transition probabilities (A), branching ratios ({beta}{sub R}) and peak stimulated emission cross section ({sigma}E/P) for the {sup 5}D{sub 0} {yields} {sup 7}F{sub J} (J = 1, 2, 3 and 4) transitions of the Eu{sup 3+} ions. The varying optical properties of the prepared glasses with the change in tellurium dioxide have

  12. Spectroscopic Investigation of Composite Polymeric and Monocrystalline Systems with Ionic Conductivity

    Directory of Open Access Journals (Sweden)

    Darya V. Radziuk

    2011-03-01

    Full Text Available The conductivity mechanism is studied in the LiCF3SO3-doped polyethylene oxide by monitoring the vibrations of sulfate groups and mobility of Li+ ion along the polymeric chain at different EO/Li molar ratios in the temperature range from 16 to 90 °С. At the high EO/Li ratio (i.e., 30, the intensity of bands increases and a triplet appears at 1,045 cm−1, indicating the presence of free anions, ionic pairs and aggregates. The existence of free ions in the polymeric electrolyte is also proven by the red shift of bands in Raman spectra and a band shift to the low frequency Infra-red region at 65 < T < 355 °С. Based on quantum mechanical modeling, (method MNDO/d, the energies (minimum and maximum correspond to the most probable and stable positions of Li+ along the polymeric chain. At room temperature, Li+ ion overcomes the intermediate state (minimum energy through non-operating transitions (maximum energy due to permanent intrapolymeric rotations (rotation of C, H and O atoms around each other. In solid electrolyte (Li2SO4 the mobility of Li+ ions increases in the temperature range from 20 to 227 °С, yielding higher conductivity. The results of the present work can be practically applied to a wide range of compact electronic devices, which are based on polymeric or solid electrolytes.

  13. Isolated centres versus defect associates in Sm3+-doped CeO2: a spectroscopic investigation

    International Nuclear Information System (INIS)

    Tiseanu, Carmen; Avram, Daniel; Cojocaru, Bogdan; Parvulescu, Vasile I; Vela-Gonzalez, Andrea V; Sanchez-Dominguez, Margarita

    2013-01-01

    The interactions between Sm 3+ and oxygen vacancies in CeO 2 are probed by the use of tuneable laser excited time-resolved photoluminescence and Raman spectroscopies. It is found that Sm 3+ (with doping concentrations of 0.1, 0.3, 1 and 5 wt%) substitutes largely for Ce 4+ in sites with cubic symmetry and the corresponding emission is sensitized via the Ce 4+ –O 2− charge-transfer band of CeO 2 . It is established from the photoluminescence spectra measured at long delay after the laser pulse that the local environment around cubic Sm 3+ centres is not changed with concentration and ceria size. In addition to cubic symmetry Sm 3+ centres, low-symmetry Sm 3+ centres tentatively assigned to the Sm 3+ –oxygen vacancy associates of nearest-neighbour type are also observed. Their emission is preferentially excited via the weak f–f absorption transitions of Sm 3+ . A relatively strong concentration-induced quenching of Sm 3+ emission was inferred from the decrease in the average emission lifetimes from 2.1 ms (0.1 wt%) to 0.87 ms (5 wt%). The local environments of Sm 3+ and Eu 3+ in CeO 2 are also compared on the basis of their emission spectra and decays. (paper)

  14. Real time spectroscopic ellipsometry investigation of homoepitaxial GaN grown by plasma assisted molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tong-Ho; Choi, Soojeong; Wu, Pae; Brown, April [Department of Electrical and Computer Engineering, Duke University, 128 Hudson Hall, Durham, NC (United States); Losurdo, Maria; Giangregorio, Maria M.; Bruno, Giovanni [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR and INSTM UdR Bari, via Orabona, 4, 70126 Bari (Italy); Moto, Akihiro [Innovation Core SEI, Inc., 3235 Kifer Road, Santa Clara, CA 95051 (United States)

    2006-06-15

    The growth of GaN by plasma assisted molecular beam epitaxy on GaN template substrates (GaN on sapphire) is investigated with in-situ multi-channel spectroscopic ellipsometry. Growth is performed under various Ga/N flux ratios at growth temperatures in the range 710-780 C. The thermal roughening of the GaN template caused by decomposition of the surface is investigated through the temporal variation of the GaN pseudodielectric function over the temperature range of 650 C to 850 C. The structural, morphological, and optical properties are also discussed. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Spectroscopic investigations on the interaction of thioacetamide with ZnO quantum dots and application for its fluorescence sensing.

    Science.gov (United States)

    Saha, Dipika; Negi, Devendra P S

    2018-01-15

    The purpose of the present work was to develop a method for the sensing of thioacetamide by using spectroscopic techniques. Thioacetamide is a carcinogen and it is important to detect its presence in food-stuffs. Semiconductor quantum dots are frequently employed as sensing probes since their absorption and fluorescence properties are highly sensitive to the interaction with substrates present in the solution. In the present work, the interaction between thioacetamide and ZnO quantum dots has been investigated by using UV-visible, fluorescence and infrared spectroscopy. Besides, dynamic light scattering (DLS) has also been utilized for the interaction studies. UV-visible absorption studies indicated the bonding of the lone pair of sulphur atom of thioacetamide with the surface of the semiconductor. The fluorescence band of the ZnO quantum dots was found to be quenched in the presence of micromolar concentrations of thioacetamide. The quenching was found to follow the Stern-Volmer relationship. The Stern-Volmer constant was evaluated to be 1.20×10 5 M -1 . Infrared spectroscopic measurements indicated the participation of the NH 2 group and the sulphur atom of thioacetamide in bonding with the surface of the ZnO quantum dots. DLS measurements indicated that the surface charge of the semiconductor was shielded by the thioacetamide molecules. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Spectroscopic investigations on the interaction of thioacetamide with ZnO quantum dots and application for its fluorescence sensing

    Science.gov (United States)

    Saha, Dipika; Negi, Devendra P. S.

    2018-01-01

    The purpose of the present work was to develop a method for the sensing of thioacetamide by using spectroscopic techniques. Thioacetamide is a carcinogen and it is important to detect its presence in food-stuffs. Semiconductor quantum dots are frequently employed as sensing probes since their absorption and fluorescence properties are highly sensitive to the interaction with substrates present in the solution. In the present work, the interaction between thioacetamide and ZnO quantum dots has been investigated by using UV-visible, fluorescence and infrared spectroscopy. Besides, dynamic light scattering (DLS) has also been utilized for the interaction studies. UV-visible absorption studies indicated the bonding of the lone pair of sulphur atom of thioacetamide with the surface of the semiconductor. The fluorescence band of the ZnO quantum dots was found to be quenched in the presence of micromolar concentrations of thioacetamide. The quenching was found to follow the Stern-Volmer relationship. The Stern-Volmer constant was evaluated to be 1.20 × 105 M- 1. Infrared spectroscopic measurements indicated the participation of the sbnd NH2 group and the sulphur atom of thioacetamide in bonding with the surface of the ZnO quantum dots. DLS measurements indicated that the surface charge of the semiconductor was shielded by the thioacetamide molecules.

  17. Investigation of lipid homeostasis in living Drosophila by coherent anti-Stokes Raman scattering microscopy

    Science.gov (United States)

    Chien, Cheng-Hao; Chen, Wei-Wen; Wu, June-Tai; Chang, Ta-Chau

    2012-12-01

    To improve our understanding of lipid metabolism, Drosophila is used as a model animal, and its lipid homeostasis is monitored by coherent anti-Stokes Raman scattering microscopy. We are able to achieve in vivo imaging of larval fat body (analogous to adipose tissue in mammals) and oenocytes (analogous to hepatocytes) in Drosophila larvae at subcellular level without any labeling. By overexpressing two lipid regulatory proteins-Brummer lipase (Bmm) and lipid storage droplet-2 (Lsd-2)-we found different phenotypes and responses under fed and starved conditions. Comparing with the control larva, we observed more lipid droplet accumulation by ˜twofold in oenocytes of fat-body-Bmm-overexpressing (FB-Bmm-overexpressing) mutant under fed condition, and less lipid by ˜fourfold in oenocytes of fat-body-Lsd-2-overexpressing (FB-Lsd-2-overexpressing) mutant under starved condition. Moreover, together with reduced size of lipid droplets, the lipid content in the fat body of FB-Bmm-overexpressing mutant decreases much faster than that of the control and FB-Lsd-2-overexpressing mutant during starvation. From long-term starvation assay, we found FB-Bmm-overexpressing mutant has a shorter lifespan, which can be attributed to faster consumption of lipid in its fat body. Our results demonstrate in vivo observations of direct influences of Bmm and Lsd-2 on lipid homeostasis in Drosophila larvae.

  18. Investigation of Surface Enhanced Coherent Raman Scattering on Nano-patterned Insect Wings

    Science.gov (United States)

    Ujj, Laszlo; Lawhead, Carlos

    2015-03-01

    Many insect wings (cicadas, butterflies, mosquitos) poses nano-patterned surface structure. Characterization of surface morphology and chemical composition of insect wings is important to understand the extreme mechanical properties and the biophysical functionalities of the wings. We have measured the image of the membrane of a cicada's wing with the help of Scanning Electron Microscopy (SEM). The results confirm the existing periodic structure of the wing measured previously. In order to identify the chemical composition of the wing, we have deposited silver nanoparticles on it and applied Coherent anti-Stokes Raman Spectroscopy to measure the vibrational spectra of the molecules comprising the wing for the first time. The measured spectra are consistent with the original assumption that the wing membrane is composed of protein, wax, and chitin. The results of these studies can be used to measure other nano-patterned surfaces and to make artificial materials in the future. Authors grateful for financial support from the Department of Physics of the College of Sciences Engineering and Health of UWF and the Pall Corporation for SEM imaging.

  19. The investigation of the interaction between edaravone and bovine serum albumin by spectroscopic approaches

    International Nuclear Information System (INIS)

    Yu Xianyong; Yang Ying; Liu Ronghua; Huang Haowen; Chen Jian; Ji Danhong; Li Xiaofang; Yang Fengxian; Yi Pinggui

    2011-01-01

    The fluorescence and ultraviolet spectroscopies were explored to study the interaction between edaravone (EDA) and bovine serum albumin (BSA) under imitated physiological condition. The experimental results show that the fluorescence quenching mechanism between EDA and BSA is a combined quenching (dynamic and static quenching). The binding constants, binding sites, and the corresponding thermodynamic parameters (ΔG, ΔH, and ΔS) of the interaction system were calculated at different temperatures. According to Foerster non-radiation energy transfer theory, the binding distance between EDA and BSA was calculated to be 3.10 nm. The effect of EDA on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy. In addition, the effects of some common metal ions Mg 2+ , Ca 2+ , Cu 2+ , and Ni 2+ on the binding constant between EDA and BSA were examined. - Highlights: → We explored the interaction of BSA and EDA using spectroscopic methods. → The fluorescence quenching mechanism is combined quenching. → Hydrophobic interaction force plays a major role in stabilizing the complex. → The binding constants, binding sites, and thermodynamic parameters were calculated. → EDA affects the conformation of tryptophan residue's microregion.

  20. The investigation of the interaction between edaravone and bovine serum albumin by spectroscopic approaches

    Energy Technology Data Exchange (ETDEWEB)

    Xianyong, Yu; Ying, Yang; Ronghua, Liu; Haowen, Huang; Jian, Chen; Danhong, Ji [Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education, Hunan Province College Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Li Xiaofang, E-mail: fine_chem@163.co [Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education, Hunan Province College Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Fengxian, Yang [Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education, Hunan Province College Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Yi Pinggui, E-mail: pgyi@hnust.c [Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education, Hunan Province College Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China)

    2011-07-15

    The fluorescence and ultraviolet spectroscopies were explored to study the interaction between edaravone (EDA) and bovine serum albumin (BSA) under imitated physiological condition. The experimental results show that the fluorescence quenching mechanism between EDA and BSA is a combined quenching (dynamic and static quenching). The binding constants, binding sites, and the corresponding thermodynamic parameters ({Delta}G, {Delta}H, and {Delta}S) of the interaction system were calculated at different temperatures. According to Foerster non-radiation energy transfer theory, the binding distance between EDA and BSA was calculated to be 3.10 nm. The effect of EDA on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy. In addition, the effects of some common metal ions Mg{sup 2+}, Ca{sup 2+}, Cu{sup 2+}, and Ni{sup 2+} on the binding constant between EDA and BSA were examined. - Highlights: {yields} We explored the interaction of BSA and EDA using spectroscopic methods. {yields} The fluorescence quenching mechanism is combined quenching. {yields} Hydrophobic interaction force plays a major role in stabilizing the complex. {yields} The binding constants, binding sites, and thermodynamic parameters were calculated. {yields} EDA affects the conformation of tryptophan residue's microregion.

  1. Spectroscopic investigation on interaction of toluidine blue/ AOT/ γ-cyclodextrin ternary system

    Energy Technology Data Exchange (ETDEWEB)

    Dasmandal, Somnath; Bhattacharyya, Debabrata; Rudra, Suparna; Patel, Biman Kumar; Mahapatra, Ambikesh, E-mail: amahapatra@chemistry.jdvu.ac.in

    2016-11-15

    Interaction of toluidine blue (TB), a biologically potent cationic phenothiazinium dye, with anionic surfactant, sodium bis(2-ethylhexyl) sulfosuccinate (AOT) have been thoroughly studied employing absorption and emission spectroscopy. A completely distinct spectral behavior of TB has been observed corresponding to pre-micellar and post-micellar region of AOT. Steady-state fluorescence anisotropy measurement has been carefully undertaken to rationalize the spectroscopic results. Effect of γ-cyclodextrin (γ-CD) on the spectral properties of TB has also been encountered for understanding of binding interaction between them. Molecular docking study has been accomplished to enlighten the probable orientation of TB inside the γ-CD core. Here particular interest has been focused on a mixed system, composed of AOT pre-micelles and γ-CD. A remarkable diminution of both absorption and emission intensities of TB has been observed in AOT pre-micelle with a simultaneous colorimetric change of TB solution from dark blue to lavender, and subsequent addition of γ-CD results in enhancement of intensities with dramatic reversal of the lavender colored solution to the original dark blue color. The emission characteristics of TB in the presence of AOT and γ-CD may prove as promising for an ‘IMPLICATION’ logic gate which may perform a significant role in the field of molecular electronics.

  2. Raman spectroscopic measurements of CO2 density: Experimental calibration with high-pressure optical cell (HPOC) and fused silica capillary capsule (FSCC) with application to fluid inclusion observations

    Science.gov (United States)

    Wang, X.; Chou, I-Ming; Hu, W.; Burruss, Robert; Sun, Q.; Song, Y.

    2011-01-01

    Raman spectroscopy is a powerful method for the determination of CO2 densities in fluid inclusions, especially for those with small size and/or low fluid density. The relationship between CO2 Fermi diad split (Δ, cm−1) and CO2 density (ρ, g/cm3) has been documented by several previous studies. However, significant discrepancies exist among these studies mainly because of inconsistent calibration procedures and lack of measurements for CO2fluids having densities between 0.21 and 0.75 g/cm3, where liquid and vapor phases coexist near room temperature.In this study, a high-pressure optical cell and fused silica capillary capsules were used to prepare pure CO2 samples with densities between 0.0472 and 1.0060 g/cm3. The measured CO2 Fermi diad splits were calibrated with two well established Raman bands of benzonitrile at 1192.6 and 1598.9 cm−1. The relationship between the CO2 Fermi diad split and density can be represented by: ρ = 47513.64243 − 1374.824414 × Δ + 13.25586152 × Δ2 − 0.04258891551 × Δ3(r2 = 0.99835, σ = 0.0253 g/cm3), and this relationship was tested by synthetic fluid inclusions and natural CO2-rich fluid inclusions. The effects of temperature and the presence of H2O and CH4 on this relationship were also examined.

  3. Crystallographic and spectroscopic investigations on nine metal-rare-earth silicates with the apatite structure type

    International Nuclear Information System (INIS)

    Wierzbicka-Wieczorek, Maria; Goeckeritz, Martin; Kolitsch, Uwe; Lenz, Christoph; Giester, Gerald

    2015-01-01

    Nine silicates with the apatite structure type (space group P6 3 /m) containing both rare-earth elements (REEs: Pr, Nd, Sm, Tb, Ho and Er) and various metals (K, Sr, Ba and Cd) were synthesised by high-temperature flux-growth techniques and characterised by single-crystal X-ray diffraction, scanning electron microscopy, Raman spectroscopy and laser-induced photoluminescence spectroscopy. In all of the compounds, the 6h Wyckoff position is predominantly or solely occupied by REE 3+ cations, whereas the cations shows a mixed occupancy at the larger, nine-coordinate 4f site with 55-75 % of REE 3+ cations and 45-25 % of other metal cations. The O4 (''free'' oxygen) site is fully occupied by O 2- anions, except for a Ba-Pr member with full occupancy by F - anions. The refined formulas are Cd 2 Er 8 (SiO 4 ) 6 O 2 , Cd 2 Tb 8 (SiO 4 ) 6 O 2 , KHo 9 (SiO 4 ) 6 O 2 , KTb 9 (SiO 4 ) 6 O 2 , KSm 9 (SiO 4 ) 6 O 2 , Sr 2 Nd 8 (SiO 4 ) 6 O 2 , Ba 2 Nd 8 (SiO 4 ) 6 O 2 , Ba 2 Sm 8 (SiO 4 ) 6 O 2 and Ba 4 Pr 6 (SiO 4 ) 6 F 2 . Changes in the metaprism twist angle (φ) and correlations between the unit-cell parameters, average cationic radii (of M + /M 2+ -REE 3+ pairs) and the chemistry of both the synthesised M + /M 2+ -REE 3+ silicate apatites and those reported previously are evaluated. Photoluminescence measurements of undoped samples yielded emission bands in the visible region from green to red; therefore, these compounds are potential candidates for luminescent materials. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Structural and vibrational spectral investigations of melaminium maleate monohydrate by FTIR, FT-Raman and quantum chemical calculations

    Science.gov (United States)

    Arjunan, V.; Kalaivani, M.; Marchewka, M. K.; Mohan, S.

    2013-04-01

    The structural investigations of the molecular complex of melamine with maleic acid, namely melaminium maleate monohydrate have been carried out by quantum chemical methods in addition to FTIR, FT-Raman and far-infrared spectral studies. The quantum chemical studies were performed with DFT (B3LYP) method using 6-31G**, cc-pVDZ and 6-311++G** basis sets to determine the energy, structural and thermodynamic parameters of melaminium maleate monohydrate. The hydrogen atom from maleic acid was transferred to the melamine molecule giving the singly protonated melaminium cation. The ability of ions to form spontaneous three-dimensional structure through weak Osbnd H⋯O and Nsbnd H⋯O hydrogen bonds shows notable vibrational effects.

  5. Structural and vibrational spectral investigations of melaminium maleate monohydrate by FTIR, FT-Raman and quantum chemical calculations.

    Science.gov (United States)

    Arjunan, V; Kalaivani, M; Marchewka, M K; Mohan, S

    2013-04-15

    The structural investigations of the molecular complex of melamine with maleic acid, namely melaminium maleate monohydrate have been carried out by quantum chemical methods in addition to FTIR, FT-Raman and far-infrared spectral studies. The quantum chemical studies were performed with DFT (B3LYP) method using 6-31G(**), cc-pVDZ and 6-311++G(**) basis sets to determine the energy, structural and thermodynamic parameters of melaminium maleate monohydrate. The hydrogen atom from maleic acid was transferred to the melamine molecule giving the singly protonated melaminium cation. The ability of ions to form spontaneous three-dimensional structure through weak OH···O and NH···O hydrogen bonds shows notable vibrational effects. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Theoretical and spectroscopic investigation of the oxidation and degradation of protocatechuic acid

    International Nuclear Information System (INIS)

    Hatzipanayioti, Despina; Karaliota, Alexandra; Kamariotaki, Mary; Aletras, Vasilios; Petropouleas, Panayiotis

    2006-01-01

    In this work, we report a combined experimental and theoretical study on molecular structure and spectroscopic properties of the most stable conformers of PCA. 1 H, 13 C NMR and 2D COSY NMR, ESR, IR and electronic spectroscopies were coupled with DFT theoretical calculations performed at the B3LYP/6-31G** level. The calculated geometrical parameters for the neutral protocatechuic acid PCA-H 3 , its anions, its oxidized forms and the peroxo-derivative [PCA-H-O 2 ] 2- are in line with the experimental data. The neutral catecholate is the most stable form of PCA-H 3 whilst the dianion [PCA-H] 2- presents higher energy. This anion is (experimentally) stable only under argon, reacting with dioxygen, in the presence of air. The semiquinone [PCA-H-sq(3)] - is very close in energy from [PCA-H-sq(4)] - form and an equilibrium between these two oxidized radical forms might be expected. The energetically advantageous pathway for preparation of the symmetrically delocalized [PCA-sq] 2- is to oxidize the [PCA] 3- . The occurrence of this radical dianion form was justified experimentally by ESR, IR, UV-vis and NMR spectra. The structural calculations for [PCA-H-O 2 ] 2- indicate that C 3 (and to a lesser extent C1) may undergo a nucleophilic attack from the 'co-ordinated' peroxo-group. The conditions for the non-enzymatic degradation of PCA have been established and some new products are observed: ionization of PCA-H 3 , the presence of O 2 and aprotic solvents provide the semiquinone-superoxo adduct which is then degraded to lactones, while in protic solvents, addition of H 2 O 2 and the presence of air, are essential, providing aliphatic degradation products

  7. Vibrational spectroscopic (FT-IR, FT-Raman) and quantum mechanical study of 4-(2-chlorophenyl)-2-ethyl-9-methyl-6H-thieno[3,2-f] [1,2,4]triazolo[4,3-a][1,4] diazepine

    Science.gov (United States)

    Kuruvilla, Tintu K.; Prasana, Johanan Christian; Muthu, S.; George, Jacob

    2018-04-01

    The spectroscopic properties of 4-(2-chlorophenyl)-2-ethyl-9-methyl-6H-thieno [3,2-f] [1,2,4] triazolo [4,3-a] [1,4] diazepine were investigated in the present study using FT-IR and FT-Raman techniques. The results obtained were compared with quantum mechanical methods, as it serves as an important tool in interpreting and predicting vibrational spectra. The optimized molecular geometry, the vibrational wavenumbers, the infrared intensities and Raman scattering were calculated using density functional theory B3LYP method with 6-311++g (d,p) basis set. All the experimental results were in line with the theoretical data. The molecular electrostatic potential (MEP) and HOMO LUMO energies of the title compound were accounted. The results indicated that the title compound has a lower softness value (0.27) and high electrophilicity index (4.98) hence describing its biological activity. Further, natural bond orbital was also analyzed as part of the work. Fukui functions were calculated in order to explain the chemical selectivity or the reactivity site in 4-(2-chlorophenyl)-2-ethyl-9-methyl-6H-thieno [3,2-f] [1,2,4] triazolo [4,3-a] [1,4] diazepine. The thermodynamic properties of the title compound were closely examined at different temperatures. It revealed the correlations between heat capacity (C), entropy (S) and enthalpy changes (H) with temperatures. The paper further explains that the title compound can act as good antidepressant through molecular docking studies.

  8. Raman-microscopy investigation of vitrification-induced structural damages in mature bovine oocytes.

    Directory of Open Access Journals (Sweden)

    Giulia Rusciano

    Full Text Available Although oocyte cryopreservation has great potentials in the field of reproductive technologies, it still is an open challenge in the majority of domestic animals and little is known on the biochemical transformation induced by this process in the different cellular compartments. Raman micro-spectroscopy allows the non-invasive evaluation of the molecular composition of cells, based on the inelastic scattering of laser photons by vibrating molecules. The aim of this work was to assess the biochemical modifications of both the zona pellucida and cytoplasm of vitrified/warmed in vitro matured bovine oocytes at different post-warming times. By taking advantage of Principal Component Analysis, we were able to shed light on the biochemical transformation induced by the cryogenic treatment, also pointing out the specific role of cryoprotective agents (CPs. Our results suggest that vitrification induces a transformation of the protein secondary structure from the α-helices to the β-sheet form, while lipids tend to assume a more packed configuration in the zona pellucida. Both modifications result in a mechanical hardening of this cellular compartment, which could account for the reduced fertility rates of vitrified oocytes. Furthermore, biochemical modifications were observed at the cytoplasmic level in the protein secondary structure, with α-helices loss, suggesting cold protein denaturation. In addition, a decrease of lipid unsaturation was found in vitrified oocytes, suggesting oxidative damages. Interestingly, most modifications were not observed in oocytes exposed to CPs, suggesting that they do not severely affect the biochemical architecture of the oocyte. Nevertheless, in oocytes exposed to CPs decreased developmental competence and increased reactive oxygen species production were observed compared to the control. A more severe reduction of cleavage and blastocyst rates after in vitro fertilization was obtained from vitrified oocytes. Our

  9. Supramolecular architecture of 5-bromo-7-methoxy-1-methyl-1H-benzoimidazole.3H2O: Synthesis, spectroscopic investigations, DFT computation, MD simulations and docking studies

    Science.gov (United States)

    Murthy, P. Krishna; Smitha, M.; Sheena Mary, Y.; Armaković, Stevan; Armaković, Sanja J.; Rao, R. Sreenivasa; Suchetan, P. A.; Giri, L.; Pavithran, Rani; Van Alsenoy, C.

    2017-12-01

    Crystal and molecular structure of newly synthesized compound 5-bromo-7-methoxy-1-methyl-1H-benzoimidazole (BMMBI) has been authenticated by single crystal X-ray diffraction, FT-IR, FT-Raman, 1H NMR, 13C NMR and UV-Visible spectroscopic techniques; compile both experimental and theoretical results which are performed by DFT/B3LYP/6-311++G(d,p) method at ground state in gas phase. Visualize nature and type of intermolecular interactions and crucial role of these interactions in supra-molecular architecture has been investigated by use of a set of graphical tools 3D-Hirshfeld surfaces and 2D-fingerprint plots analysis. The title compound stabilized by strong intermolecular hydrogen bonds N⋯Hsbnd O and O⋯Hsbnd O, which are envisaged by dark red spots on dnorm mapped surfaces and weak Br⋯Br contacts envisaged by red spot on dnorm mapped surface. The detailed fundamental vibrational assignments of wavenumbers were aid by with help of Potential Energy distribution (PED) analysis by using GAR2PED program and shows good agreement with experimental values. Besides frontier orbitals analysis, global reactivity descriptors, natural bond orbitals and Mullikan charges analysis were performed by same basic set at ground state in gas phase. Potential reactive sites of the title compound have been identified by ALIE, Fukui functions and MEP, which are mapped to the electron density surfaces. Stability of BMMBI have been investigated from autoxidation process and pronounced interaction with water (hydrolysis) by using bond dissociation energies (BDE) and radial distribution functions (RDF), respectively after MD simulations. In order to identify molecule's most important reactive spots we have used a combination of DFT calculations and MD simulations. Reactivity study encompassed calculations of a set of quantities such as: HOMO-LUMO gap, MEP and ALIE surfaces, Fukui functions, bond dissociation energies and radial distribution functions. To confirm the potential

  10. RAMAN SCATTERING BY MOLECULAR HYDROGEN AND NITROGEN IN EXOPLANETARY ATMOSPHERES

    Energy Technology Data Exchange (ETDEWEB)

    Oklopčić, Antonija [California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, California 91125 (United States); Hirata, Christopher M. [Center for Cosmology and Astroparticle Physics, Ohio State University, 191 West Woodruff Avenue, Columbus, Ohio 43210 (United States); Heng, Kevin, E-mail: oklopcic@astro.caltech.edu [Center for Space and Habitability, University of Bern, Sidlerstrasse 5, CH-3012, Bern (Switzerland)

    2016-11-20

    An important source of opacity in exoplanet atmospheres at short visible and near-UV wavelengths is Rayleigh scattering of light on molecules. It is accompanied by a related, albeit weaker process—Raman scattering. We analyze the signatures of Raman scattering imprinted in the reflected light and the geometric albedo of exoplanets, which could provide information about atmospheric properties. Raman scattering affects the geometric albedo spectra of planets in the following ways. First, it causes filling-in of strong absorption lines in the incident radiation, thus producing sharp peaks in the albedo. Second, it shifts the wavelengths of spectral features in the reflected light causing the so-called Raman ghost lines. Raman scattering can also cause a broadband reduction of the albedo due to wavelength shifting of a stellar spectrum with red spectral index. Observing the Raman peaks in the albedo could be used to measure the column density of gas, thus providing constraints on the presence of clouds in the atmosphere. Observing the Raman ghost lines could be used to spectroscopically identify the main scatterer in the atmosphere, even molecules like H{sub 2} or N{sub 2}, which do not have prominent spectral signatures in the optical wavelength range. If detected, ghost lines could also provide information about the temperature of the atmosphere. In this paper, we investigate the effects of Raman scattering in hydrogen- and nitrogen-dominated atmospheres. We analyze the feasibility of detecting the signatures of Raman scattering with the existing and future observational facilities, and of using these signatures as probes of exoplanetary atmospheres.

  11. Raman spectrum of asphaltene

    KAUST Repository

    Abdallah, Wael A.; Yang, Yang

    2012-01-01

    Asphaltenes extracted from seven different crude oils representing different geological formations from around the globe were analyzed using the Raman spectroscopic technique. Each spectrum is fitted with four main peaks using the Gaussian function. On the basis of D1 and G bands of the Raman spectrum, asphaltene indicated an ordered structure with the presence of boundary defected edges. The average aromatic sheet size of the asphaltene molecules is estimated within the range of 1.52-1.88 nm, which represents approximately seven to eight aromatic fused rings. This estimation is based on the integrated intensity of D1 and G bands, as proposed by Tunistra and Koenig. The results here are in perfect agreement with so many other used techniques and indicate the potential applicability of Raman measurements to determine the average aromatic ring size and its boundary. © 2012 American Chemical Society.

  12. Raman spectrum of asphaltene

    KAUST Repository

    Abdallah, Wael A.

    2012-11-05

    Asphaltenes extracted from seven different crude oils representing different geological formations from around the globe were analyzed using the Raman spectroscopic technique. Each spectrum is fitted with four main peaks using the Gaussian function. On the basis of D1 and G bands of the Raman spectrum, asphaltene indicated an ordered structure with the presence of boundary defected edges. The average aromatic sheet size of the asphaltene molecules is estimated within the range of 1.52-1.88 nm, which represents approximately seven to eight aromatic fused rings. This estimation is based on the integrated intensity of D1 and G bands, as proposed by Tunistra and Koenig. The results here are in perfect agreement with so many other used techniques and indicate the potential applicability of Raman measurements to determine the average aromatic ring size and its boundary. © 2012 American Chemical Society.

  13. Investigating organic multilayers by spectroscopic ellipsometry: specific and non-specific interactions of polyhistidine with NTA self-assembled monolayers

    Directory of Open Access Journals (Sweden)

    Ilaria Solano

    2016-04-01

    Full Text Available Background: A versatile strategy for protein–surface coupling in biochips exploits the affinity for polyhistidine of the nitrilotriacetic acid (NTA group loaded with Ni(II. Methods based on optical reflectivity measurements such as spectroscopic ellipsometry (SE allow for label-free, non-invasive monitoring of molecule adsorption/desorption at surfaces.Results: This paper describes a SE study about the interaction of hexahistidine (His6 on gold substrates functionalized with a thiolate self-assembled monolayer bearing the NTA end group. By systematically applying the difference spectra method, which emphasizes the small changes of the ellipsometry spectral response upon the nanoscale thickening/thinning of the molecular film, we characterized different steps of the process such as the NTA-functionalization of Au, the adsorption of the His6 layer and its eventual displacement after reaction with competitive ligands. The films were investigated in liquid, and ex situ in ambient air. The SE investigation has been complemented by AFM measurements based on nanolithography methods (nanografting mode.Conclusion: Our approach to the SE data, exploiting the full spectroscopic potential of the method and basic optical models, was able to provide a picture of the variation of the film thickness along the process. The combination of δΔi+1,i(λ, δΨi+1,i(λ (layer-addition mode and δΔ†i',i+1(λ, δΨ†i',i+1(λ (layer-removal mode difference spectra allowed us to clearly disentangle the adsorption of His6 on the Ni-free NTA layer, due to non specific interactions, from the formation of a neatly thicker His6 film induced by the Ni(II-loading of the NTA SAM.

  14. Spectroscopic and ultrasonic investigations on structural characterization of borate glass specimen doped with transition metal ions.

    Science.gov (United States)

    Sathish, K; Thirumaran, S

    2015-08-05

    The present work describes the glass samples of composition (x% V₂O₅-(80-x)% B₂O₃-20% Na₂CO₃) VBS glass system and (x%MnO₂-(80-x)% B₂O₃-20% Na₂CO₃) in MBS glass system with mol% ranging from x=3, 6, 9, 12, 15 and 18 in steps of 3 mol% are prepared by melt quenching technique. For these prepared glass systems, sound velocity (longitudinal and shear velocities) and density have been measured. The sound velocity (longitudinal and shear) was measured by using pulse-echo technique at 5 MHz. The XRD study was carried to out to ascertain the amorphous nature of the glass specimen. Using these measured values, the elastic moduli, Poisson's ratio, Debye temperature, acoustic impedance and thermal expansion coefficient of the two glass systems were evaluated. The elastic and mechanical properties of the prepared glass systems are analyzed from ultrasonic study and the structural characterization from spectroscopic study. The effects due to the doping of transition metal ions with borate have been discussed. In the V₂O₅ doped glass system,(VBS glass system) the sound velocity, density and elastic moduli, steeply increases after 12 mol% comparatively with MnO₂ doped glass system (VBS glass system). The present study critically observes the doping of V₂O₅ with borate enhances the strengthening of network linkage and hardening of the glassy network structure than MnO₂. The IR spectral analysis reveals depolymerization of the borate network and conversion of BO₃ or BO4 units with the formation of non-bridging oxygen. The FTIR spectral studies confirm the presence of various functional groups of the sample. FTIR spectrum of sample exhibits broad absorption bands indicating the wide distribution of borate structural units. The effect of Na₂CO₃, V₂O₅ and MnO₂ contents on the structures of borate glass is evaluated from the FTIR spectra. The topological aspects of the prepared glass samples are exhaustively reported from SEM micrographs

  15. Time resolved spectroscopic investigation of SiD2 + D2: kinetic study

    Science.gov (United States)

    Al-Rubaiey, Najem A.; Walsh, Robin

    2017-03-01

    Silylenes (silanediyls) have made an important impact on organosilicon chemistry even if it is of more recent foundation than carbenes in organic chemistry and much less complete. These species are highly reactive intermediates. They play a central role in the chemical vapour deposition (CVD) of various silicon-containing thin films which have a technological importance in microelectronics as well as in the dry etching processes of silicon wafers. Spectroscopic methods have been developed to observe these species, a necessary pre-requisite to their direct monitoring. In this work, deuterated phenylsilane precursor, PhSiD3 was chosen for SiD2 because its analogue phenylsilane, PhSiH3 proved to be a good precursor for SiH2 and the high quality decay signals observed revealed that SiD2 be readily detected from PhSiD3 and that if other decomposition pathways (e.g. PhSiD + D2) are occurring, they do not effect measurements of the rate constants for SiD2. The absorption spectrum of SiD2 formed from the flash photolysis of a mixture of PhSiD3 and SF6 at 193nm were found in the region 17384-17391 cm-1 with strong band at 17387.07 cm-1. This single rotational line of pQ1 was chosen to monitor SiD2 removal. Time-resolved studies of SiD2 have been carried out to obtain rate constants for its bimolecular reactions with D2. The reactions were studied over the pressure range 5-100 Torr (in SF6 bath gas) at four temperatures in the range 298-498K. Single decay from 10 photolysis laser shots were averaged and found to give reasonable first-order kinetics fits. Second order kinetics were obtained by pressure dependence of the pseudo first order decay constants and substance D2 pressures within experimental error. The reaction was found to be weakly pressure dependent at all temperatures, consistent with a third-body mediated association process. In addition, SiH2+ H2 reaction is approximately ca. 60% faster than SiD2+D2 reaction. Theoretical extrapolations (using Lindemann

  16. Time resolved spectroscopic investigation of SiD2 + D2: kinetic study

    Directory of Open Access Journals (Sweden)

    Al-Rubaiey Najem A.

    2017-01-01

    Full Text Available Silylenes (silanediyls have made an important impact on organosilicon chemistry even if it is of more recent foundation than carbenes in organic chemistry and much less complete. These species are highly reactive intermediates. They play a central role in the chemical vapour deposition (CVD of various silicon-containing thin films which have a technological importance in microelectronics as well as in the dry etching processes of silicon wafers. Spectroscopic methods have been developed to observe these species, a necessary pre-requisite to their direct monitoring. In this work, deuterated phenylsilane precursor, PhSiD3 was chosen for SiD2 because its analogue phenylsilane, PhSiH3 proved to be a good precursor for SiH2 and the high quality decay signals observed revealed that SiD2 be readily detected from PhSiD3 and that if other decomposition pathways (e.g. PhSiD + D2 are occurring, they do not effect measurements of the rate constants for SiD2. The absorption spectrum of SiD2 formed from the flash photolysis of a mixture of PhSiD3 and SF6 at 193nm were found in the region 17384-17391 cm-1 with strong band at 17387.07 cm-1. This single rotational line of pQ1 was chosen to monitor SiD2 removal. Time-resolved studies of SiD2 have been carried out to obtain rate constants for its bimolecular reactions with D2. The reactions were studied over the pressure range 5-100 Torr (in SF6 bath gas at four temperatures in the range 298-498K. Single decay from 10 photolysis laser shots were averaged and found to give reasonable first-order kinetics fits. Second order kinetics were obtained by pressure dependence of the pseudo first order decay constants and substance D2 pressures within experimental error. The reaction was found to be weakly pressure dependent at all temperatures, consistent with a third-body mediated association process. In addition, SiH2+ H2 reaction is approximately ca. 60% faster than SiD2+D2 reaction. Theoretical extrapolations (using

  17. The substrate matters in the Raman spectroscopy analysis of cells

    Science.gov (United States)

    Mikoliunaite, Lina; Rodriguez, Raul D.; Sheremet, Evgeniya; Kolchuzhin, Vladimir; Mehner, Jan; Ramanavicius, Arunas; Zahn, Dietrich R. T.

    2015-08-01

    Raman spectroscopy is a powerful analytical method that allows deposited and/or immobilized cells to be evaluated without complex sample preparation or labeling. However, a main limitation of Raman spectroscopy in cell analysis is the extremely weak Raman intensity that results in low signal to noise ratios. Therefore, it is important to seize any opportunity that increases the intensity of the Raman signal and to understand whether and how the signal enhancement changes with respect to the substrate used. Our experimental results show clear differences in the spectroscopic response from cells on different surfaces. This result is partly due to the difference in spatial distribution of electric field at the substrate/cell interface as shown by numerical simulations. We found that the substrate also changes the spatial location of maximum field enhancement around the cells. Moreover, beyond conventional flat surfaces, we introduce an efficient nanostructured silver substrate that largely enhances the Raman signal intensity from a single yeast cell. This work contributes to the field of vibrational spectroscopy analysis by providing a fresh look at the significance of the substrate for Raman investigations in cell research.

  18. High pressure Raman spectroscopic study of the effects of n-ethylamines and water on the 2-nitropropane/Nitric acid system

    Energy Technology Data Exchange (ETDEWEB)

    Gobin, Cedric; Petitet, Jean Pierre [Laboratoire d' Ingenierie des Materiaux et des Hautes Pressions, CNRS, Institut Galilee, Universite Paris XIII, 99 av. J-B Clement, 93430 Villetaneuse (France)

    2005-12-01

    High pressure Raman spectroscopy measurements in a diamond anvil cell (0-10 GPa) on 2-nitropropane/nitric acid/X (X=triethylamine, diethylamine, and water) ternary systems and 2-nitropropane/nitric acid/water/Y (Y=triethylamine and diethylamine) quaternary systems are reported. The modifications of the chemical behavior of the 2-nitropropane/nitric acid model system, induced by the presence of triethylamine, diethylamine, and/or water, were studied at ambient and high pressure. At ambient pressure, the ionization of the nitric acid has been observed with each of the additives. Moreover, in the case of ethylamines, new peaks have been observed and the hypothesis of a 2-nitropropane/ethylamine complex is advanced. At high pressure, the decomposition of the 2-nitropropane/nitric acid system, with an oxygen balance near zero, has been observed only in presence of triethylamine. The role of each additive to the 2-nitropropane/nitric acid system in the modification of the respective reducing and oxidizing character of the components, and in the reactivity of the system, is discussed. Several hypotheses are advanced concerning the sensitizing effect of the additives on the 2-nitropropane/nitric acid system. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  19. Quaternary ammonium oxidative demethylation: X-ray crystallographic, resonance Raman, and UV-visible spectroscopic