WorldWideScience

Sample records for line spectroscopic investigation

  1. Investigating the origin and spectroscopic variability of the near-infrared HI lines in the Herbig star VV Ser

    CERN Document Server

    López, Rebeca García; Garatti, Alessio Caratti o; Kreplin, Alexander; Weigelt, Gerd; Tambovtseva, Larisa V; Grinin, Vladimir P; Ray, Thomas P

    2015-01-01

    The origin of the near-infrared (NIR) HI emission lines in young stellar objects are not yet understood. To probe it, we present multi-epoch LBT-LUCIFER spectroscopic observations of the Pa{\\delta}, Pa{\\beta}, and Br{\\gamma} lines observed in the Herbig star VVSer, along with VLTI-AMBER Br{\\gamma} spectro-interferometric observations at medium resolution. Our spectroscopic observations show line profile variability in all the HI lines. The strongest variability is observed in the redshifted part of the line profiles. The Br{\\gamma} spectro-interferometric observations indicate that the Br{\\gamma} line emitting region is smaller than the continuum emitting region. To interpret our results, we employed radiative transfer models with three different flow configurations: magnetospheric accretion, a magneto-centrifugally driven disc wind, and a schematic bipolar outflow. Our models suggest that the HI line emission in VVSer is dominated by the contribution of an extended wind, perhaps a bipolar outflow. Although t...

  2. Line-by-line spectroscopic simulations on graphics processing units

    Science.gov (United States)

    Collange, Sylvain; Daumas, Marc; Defour, David

    2008-01-01

    We report here on software that performs line-by-line spectroscopic simulations on gases. Elaborate models (such as narrow band and correlated-K) are accurate and efficient for bands where various components are not simultaneously and significantly active. Line-by-line is probably the most accurate model in the infrared for blends of gases that contain high proportions of H 2O and CO 2 as this was the case for our prototype simulation. Our implementation on graphics processing units sustains a speedup close to 330 on computation-intensive tasks and 12 on memory intensive tasks compared to implementations on one core of high-end processors. This speedup is due to data parallelism, efficient memory access for specific patterns and some dedicated hardware operators only available in graphics processing units. It is obtained leaving most of processor resources available and it would scale linearly with the number of graphics processing units in parallel machines. Line-by-line simulation coupled with simulation of fluid dynamics was long believed to be economically intractable but our work shows that it could be done with some affordable additional resources compared to what is necessary to perform simulations on fluid dynamics alone. Program summaryProgram title: GPU4RE Catalogue identifier: ADZY_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADZY_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 62 776 No. of bytes in distributed program, including test data, etc.: 1 513 247 Distribution format: tar.gz Programming language: C++ Computer: x86 PC Operating system: Linux, Microsoft Windows. Compilation requires either gcc/g++ under Linux or Visual C++ 2003/2005 and Cygwin under Windows. It has been tested using gcc 4.1.2 under Ubuntu Linux 7.04 and using Visual C

  3. Resonance-enhanced multiphoton ionization time-of-flight mass spectrometry for detection of nitrogen containing aliphatic and aromatic compounds: resonance-enhanced multiphoton ionization spectroscopic investigation and on-line analytical application.

    Science.gov (United States)

    Streibel, T; Hafner, K; Mühlberger, F; Adam, T; Zimmermann, R

    2006-01-01

    Resonance-enhanced multiphoton ionization (REMPI) combined with time-of-flight mass spectrometry (TOFMS) is an analytical method capable of on-line monitoring of trace compounds in complex matrices. A necessary prerequisite for substance selective detection is spectroscopic investigation of the target molecules. Several organic nitrogen compounds comprising aliphatic and aromatic amines, nitrogen heterocyclic compounds, and aromatic nitriles are spectroscopically investigated with a tunable narrow bandwidth optical parametric oscillator (OPO) laser system providing a scannable wavelength range between 220 and 340 nm. These species are known as possible precursors in fuel-NO formation from combustion of solid fuels such as biomass and waste. A newly conceived double inlet system was used in this study, which allows rapid change between effusive and supersonic molecular beams. The resulting REMPI spectra of the compounds are discussed with respect to electronic transitions that could be utilized for a selective ionization of these compounds in complex mixtures such as combustion and process gases. The practicability of this approach is demonstrated by wavelength selected on-line REMPI-TOFMS detection of aniline and cyanonaphthalene in the burning chamber of a waste incineration plant. REMPI mass spectra recorded at different excitation wavelengths as well as variations in time show the utilization of species-selective REMPI-TOFMS detection for on-line monitoring of crucial substances in pollutant formation.

  4. Spectroscopic Investigation of the Mechanism of Photocatalysis

    Directory of Open Access Journals (Sweden)

    Yoshio Nosaka

    2014-11-01

    Full Text Available Reaction mechanisms of various kinds of photocatalysts have been reviewed based on the recent reports, in which various spectroscopic techniques including luminol chemiluminescence photometry, fluorescence probe method, electron spin resonance (ESR, and nuclear magnetic resonance (NMR spectroscopy were applied. The reaction mechanisms elucidated for bare and modified TiO2 were described individually. The modified visible light responsive TiO2 photocatalysts, i.e., Fe(III-deposited metal-doped TiO2 and platinum complex-deposited TiO2, were studied by detecting paramagnetic species with ESR, •O2− (or H2O2 with chemiluminescence photometry, and OH radicals with a fluorescence probe method. For bare TiO2, the difference in the oxidation mechanism for the different crystalline form was investigated by the fluorescence probe method, while the adsorption and decomposition behaviors of several amino acids and peptides were investigated by 1H-NMR spectroscopy.

  5. Synthesis and Spectroscopic Investigation of Azoporphyrins

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The synthesis of a series of new covalently-connected azoporphyrin derivatives is described and the photochemical properties of the new compounds are discussed. The two chromophores of these derivatives exhibit their absorption spectroscopic properties respectively.In the fluorescence emission spectra, intermolecular fluorescence quenching is detected.

  6. HIPPARCOS PHOTOCENTRIC ORBITS OF 72 SINGLE-LINED SPECTROSCOPIC BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Ren Shulin; Fu Yanning, E-mail: rensl@pmo.ac.cn, E-mail: fyn@pmo.ac.cn [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

    2013-03-15

    By fitting the Hipparcos Intermediate Astrometric Data (HIAD), photocentric orbits can be obtained for the single-lined spectroscopic binaries (SB1s). In previous work, a simplifying approximation used in the fitting process was that the photocenter coincides with the primary, but simple arguments based on a mass-luminosity relation show that this approximation will introduce non-negligible deviation into photocentric orbits of a few SB1s. By fitting the revised HIAD without the approximation, the present paper tries to provide reliable photocentric orbits for those SB1s in the 9th Catalogue of Orbits of Spectroscopic Binaries having a reliable spectroscopic orbit of period between 50 days and 3.2 years. After a stringent assessment and screening process, we finally accept the photocentric orbits of 72 systems. Among these results, 37 orbits are obtained here for the first time. So far, only three of these systems are resolved with a known relative orbit. For each of them, the paired photocentric and relative orbits are in reasonably good agreement. For the 25 systems with a main-sequence primary, the masses of component stars and the semimajor axes of relative orbits are estimated for the purpose of planning ground-based observations.

  7. Spectroscopic investigations of carious tooth decay.

    Science.gov (United States)

    Thareja, R K; Sharma, A K; Shukla, Shobha

    2008-11-01

    We report on the elemental composition of healthy and infected part of human tooth using laser induced breakdown spectroscopy (LIBS). We have used prominent constituent transitions in laser-excited tooth to diagnose the state of the tooth. A nanosecond laser pulse (355nm, 5ns) was used as an ablating pulse and the sodium (3s2S-3p2P) at 588.99 and (3s2S-3p2P) at 589.99nm, strontium (5s21S-1s5P) at 460.55nm, and calcium (3d3D-4f 3F0) at 452.55nm transitions for spectroscopic analysis. The spectroscopic observations in conjunction with discriminate analysis showed that calcium attached to the hydroxyapatite structure of the tooth was affected severely at the infected part of the tooth. The position-time plots generated from two-dimensional (2D) images conclusively showed a decrease in calcium concentration in the infected region of the irradiated tooth. Using the technique, we could distinguish between the healthy and carious parts of the tooth with significant accuracy.

  8. Mm-Wave Spectroscopic Sensors, Catalogs, and Uncatalogued Lines

    Science.gov (United States)

    Medvedev, Ivan; Neese, Christopher F.; De Lucia, Frank C.

    2014-06-01

    Analytical chemical sensing based on high resolution rotational molecular spectra has been recognized as a viable technique for decades. We recently demonstrated a compact implementation of such a sensor. Future generations of these sensors will rely on automated algorithms for quantification of chemical dilutions based on their spectral libraries, as well as identification of spectral features not present in spectral catalogs. Here we present an algorithm aimed at detection of unidentified lines in complex molecular species based on spectroscopic libraries developed in our previous projects. We will discuss the approaches suitable for data mining in feature-rich rotational molecular spectra. Neese, C.F., I.R. Medvedev, G.M. Plummer, A.J. Frank, C.D. Ball, and F.C. De Lucia, "A Compact Submillimeter/Terahertz Gas Sensor with Efficient Gas Collection, Preconcentration, and ppt Sensitivity." Sensors Journal, IEEE, 2012. 12(8): p. 2565-2574

  9. Impact of difference in absorption line parameters in spectroscopic databases on CO2 and CH4 atmospheric content retrievals

    Science.gov (United States)

    Chesnokova, T. Yu.; Chentsov, A. V.; Rokotyan, N. V.; Zakharov, V. I.

    2016-09-01

    The impact of uncertainties in CH4 and CO2 absorption line parameters in modern spectroscopic databases on the atmospheric transmission simulation in the near-infrared region is investigated. The atmospheric contents of CH4 and CO2 are retrieved from the absorption solar spectra measured by a ground-based Fourier transform spectrometer. Different spectroscopic databases are used in the forward radiative transfer model and a comparison of the retrieved results is made.

  10. Line image sensors for spectroscopic applications in the extreme ultraviolet

    Science.gov (United States)

    Banyay, Matus; Brose, Sascha; Juschkin, Larissa

    2009-10-01

    The spectral range of extreme ultraviolet radiation (XUV or EUV) is an active area of research incorporating many scientific fields such as microscopy, lithography or reflectometry. During the last decade, a lot of effort has been put into transferring many of the known techniques developed at linear accelerators into the laboratory using discharge-produced plasmas (DPPs) or laser-produced plasmas (LPPs) as an alternative light source. In particular, the semiconductor industry is in need of on-site tools in the shorter wavelength range for production and inspection of structured surfaces with nanometer resolution. Here traditional charge coupled device (CCD) image sensors are inapplicable as detectors because of the strong absorption of XUV by matter prohibiting any generation of electron-hole pairs inside a deep lying p-n junction. As a solution, two-dimensional backthinned CCDs are available in the market offering high sensitivity to XUV light. Although for many applications a one-dimensional line scanning image sensor would be sufficient, they are non-existent for XUV. It is only lately that manufacturers have started to adopt the principle of backthinning to CCD line sensors to enhance sensitivity in the long wavelength UV range (>200 nm). Here we show that generally these compact sensors offer good quantum efficiencies in the XUV which make them a candidate for many spectroscopic applications and future industrial inline inspection tools for which costly two-dimensional CCDs are oversized. We have successfully implemented a compact sensor device into a laboratory XUV spectrometer and reflectometer. Our measurements compare the quantum efficiency of a state-of-the-art XUV array CCD to a phosphor-coated line sensor and a new backthinned line sensor. Additionally, we show recorded spectra from a laboratory DPP source to demonstrate the potential of a wide range of applications.

  11. Spectroscopic investigations of divertor detachment in TCV

    CERN Document Server

    Verhaegh, K; Duval, B P; Harrison, J R; Reimerdes, H; Theiler, C; Labit, B; Maurizio, R; Marini, C; Nespoli, F; Sheikh, U; Tsui, C K; Vianello, N; Vijvers, W A J

    2016-01-01

    The aim of this work is to provide an understanding of detachment at TCV with emphasis on analysis of the Balmer line emission. A new Divertor Spectroscopy System has been developed for this purpose. Further development of Balmer line analysis techniques has allowed detailed information to be extracted on free-free and three-body recombination. During density ramps, the plasma at the target detaches as inferred from a drop in density at, and ion current to, the target. At the same time the Balmer $6\\rightarrow2$ and $7\\rightarrow2$ line emission near the target is dominated by recombination, indicating that the ionization region has also detached from the target to be replaced by a recombining region with densities more than a factor 2 higher than at the target. As the core density increases further, the density and recombination rate are rising all along the outer leg to the x-point while remaining highest at the target. Even at the highest core densities accessed (Greenwald fraction 0.7) the peaks in recomb...

  12. Resolving Spectral Lines with a Periscope-Type DVD Spectroscope

    Science.gov (United States)

    Wakabayashi, Fumitaka

    2008-01-01

    A new type of DVD spectroscope, the periscope type, is described and the numerical analysis of the observed emission and absorption spectra is demonstrated. A small and thin mirror is put inside and an eighth part of a DVD is used as a grating. Using this improved DVD spectroscope, one can observe and photograph visible spectra more easily and…

  13. Terahertz spectroscopic investigation of methylenedioxy amphetamine

    Science.gov (United States)

    Wang, Guangqin; Shen, Jingling

    2008-03-01

    Experimental measurement and theoretical analysis of THz spectrum for methylenedioxy amphetamine are introduced. The refractive index and absorption coefficient of the sample were observed by terahertz time-domain spectroscopy (THz-TDS) technique in the range of 0.2~2.6 THz. It exhibits obvious absorption feature at 1.40 THz and weak THz absorption at around 1.68 and 2.21 THz. The spectral absorption characteristic in THz band was useful for the inspection and identification of drugs using THz-TDS. The theoretical calculation was performed using Density functional theory (DFT) with the GAUSSIAN 03 software package. Fully geometry optimization and frequency analysis of the optimized structure were performed at the B3LYP/6-21G levels. The simulated absorption spectrum was in agreement with the experimental data, and can hence be used for the assignment of observed THz spectrum. The theoretical simulation result showed that absorption peaks mainly result from intra-molecule and inter-molecule vibrations, different absorption peaks are corresponding to different vibrational modes and intensity. So the combination of the THz-TDS and DFT is an effective way to investigate characteristic spectra of illicit drugs.

  14. Spectroscopic investigation of local mechanical impedance of living cells

    CERN Document Server

    Costa, Luca; Benseny-Cases, Núria; Mayeaux, Véronique; Chevrier, Joël; Comin, Fabio

    2013-01-01

    The mechanical properties of PC12 living cells have been studied at the nanoscale with a Force Feedback Microscope using two experimental approaches. Firstly, the local mechanical impedance of the cell membrane has been mapped simultaneously to the cell morphology at constant force. As the force of the interaction is gradually increased, we observed the appearance of the sub-membrane cytoskeleton. We shall compare the results obtained with this method with the measurement of other existing techniques. Secondly, a spectroscopic investigation has been performed varying the indentation of the tip in the cell membrane and consequently the force applied on it. In contrast with conventional dynamic atomic force microscopy techniques, here the small oscillation amplitude of the tip is not necessarily imposed at the cantilever first eigenmode. This allows the user to arbitrarily choose the excitation frequency in developing spectroscopic AFM techniques. The mechanical response of the PC12 cell membrane is found to be...

  15. First line shape analysis and spectroscopic parameters for the ν11 band of 12C2H4

    KAUST Repository

    Es-sebbar, Et-touhami

    2016-08-11

    An accurate knowledge of line intensities, collisional broadening coefficients and narrowing parameters is necessary for the interpretation of high-resolution infrared spectra of the Earth and other planetary atmospheres. One of the most promising spectral domains for (C2H4)-C-12 monitoring in such environments is located near the 336 gm window, through its v(11) C-H stretching mode. In this paper, we report an extensive study in which we precisely determine spectroscopic parameters of (C2H4)-C-12 v(11) band at 297 +/- 1 K, using a narrow Difference-Frequency-Generation (DFG) laser with 10(-4) cm(-1) resolution. Absorption measurements were performed in the 2975-2980 cm(-1) spectral window to investigate 32 lines corresponding to where, J\\'ka\\',kc\\'<- Jka,kc, 5 <= J <= 7; 0.5 <= K-a <= 6 and 1 <= K-c <= 14. Spectroscopic parameters are retrieved using either Voigt or appropriate Galatry profile to simulate the measured (C2H4)-C-12 line shape. Line intensities along with self-broadening coefficients are reported for all lines. Narrowing coefficients for each isolated line are also derived. To our knowledge, the current study reports the first extensive spectroscopic parameter measurements of the (C2H4)-C-12 v(11) band in the 2975-2980 cm(-1) range. (C) 2016 Elsevier Ltd. All rights reserved.

  16. On-Line Multichannel Raman Spectroscopic Detection System For Capillary Zone Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An on-line multichannel Raman spectroscopic detection system for capillary electrophoresis was established by using an Ar+ laser and a cryogenically cooled ICCD. Resonant excitation Raman spectra of methyl red and methyl orange were employed to test the system. The result shows that it could yield on-line electrophoretogram and time series of Raman spectra.

  17. WR 35a: A new double-lined spectroscopic binary

    Science.gov (United States)

    Gamen, R.; Collado, A.; Barbá, R.; Chené, A.-N.; St-Louis, N.

    2014-02-01

    Aims: We present the first orbital solution for the Wolf-Rayet star, WR 35a, that was discovered by a spectroscopic monitoring of faint WN-type stars. Methods: Spectral features of two different components were identified, and thus a method of disentangling the individual spectra of both components was applied. Radial velocities were determined for each component in the binary system. Results: The orbital solution and component properties of the system were derived. We determined that WR 35a is composed of a WN6 star with a O8.5 V companion orbiting at a 41.90-day period. Table 2 is available in electronic form at http://www.aanda.org

  18. Spectroscopic Data of W I, Mo I and Cr I Spectral Lines: Selection and Analysis

    Indian Academy of Sciences (India)

    A. N. Veklich; A. V. Lebid; T. A. Tmenova

    2015-12-01

    Plasma of electric arc discharges between composite Cu–W, Cu–Mo and Cu–Cr electrodes in argon flow and their spectra were studied by optical emission spectroscopy. Since values of oscillator strengths for W I, Mo I and Cr I presented in various sources are significantly different, selection of spectroscopic data for these elements (particularly oscillator strength) was expected to be useful for plasma diagnostics. The Boltzmann plot method was used as a tool for the selection of appropriate spectral lines and their spectroscopic data. The main result of the paper is W I, Mo I and Cr I spectral lines and spectroscopic data recommended for diagnostics of plasma with such metal impurities.

  19. 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.

  20. X-ray photoelectron spectroscopic investigation of conducting polymer blends.

    Science.gov (United States)

    Süzer, S; Toppare, L; Hallam, K R; Allen, G C

    1996-06-01

    Electrochemically prepared films of conducting polymers of polypyrrole and polythiophene and their blends with polyamide have been investigated by X-ray photoelectron spectroscopy. In the N1s region of the spectra of films containing polypyrrole the peak corresponding to N(+) at 402.0 eV is separated from that of neutral N. The intensity of the N(+) peak can be correlated with the electrical conductivity of the films and the spectroscopically derived ratio of F/N(+) is close to 4 indicating that one BF(-)(4) dopant ion is incorporated for every oxidized nitrogen center. In the spectra of films of polythiophene and its blends peaks corresponding to S and S(+) can not be resolved but again the F/C ratio correlates with the electrical conductivity.

  1. Spectroscopic investigation on porphyrins nano-assemblies onto gold nanorods

    Science.gov (United States)

    Trapani, Mariachiara; De Luca, Giovanna; Romeo, Andrea; Castriciano, Maria Angela; Scolaro, Luigi Monsù

    2017-02-01

    The interaction between gold nanorods (Au NRs), synthesized by a conventional seeded growth protocol, and the anionic tetrakis-(4-sulfonatophenyl)porphyrin (TPPS4) has been investigated through various spectroscopic techniques. At neutral pH, the formation of H-aggregates and the inclusion of porphyrin monomers in CTAB micelles covering the nanorods have been evidenced. Under mild acidic conditions (pH = 3) a nano-hybrid assembly of porphyrin J-aggregates and Au NRs has been revealed. For the sake of comparison, Cu(II) and Zn(II) metal porphyrin derivatives as well as a cationic porphyrin have been studied in the same experimental conditions, showing that: i) CuTPPS4 forms porphyrin H-dimers onto the Au NRs; ii) ZnTPPS4 undergoes to demetallation, followed by acidification of the central core and eventually aggregation onto Au NRs; iii) cationic porphyrin does not interact with Au NRs.

  2. Spectroscopic Investigations of the Photophysics of Cryptophyte Light-Harvesting

    Science.gov (United States)

    Dinshaw, Rayomond

    The biological significance of photosynthesis is indisputable as it is necessary for nearly all life on earth. Photosynthesis provides chemical energy for plants, algae, and bacteria, while heterotrophic organisms rely on these species as their ultimate food source. The initial step in photosynthesis requires the absorption of sunlight to create electronic excitations. Light-harvesting proteins play the functional role of capturing solar radiation and transferring the resulting excitation to the reaction centers where it is used to carry out the chemical reactions of photosynthesis. Despite the wide variety of light-harvesting protein structures and arrangements, most light-harvesting proteins are able to utilize the captured solar energy for charge separation with near perfect quantum efficiency.1 This thesis will focus on understanding the energy transfer dynamics and photophysics of a specific subset of light-harvesting antennae known as phycobiliproteins. These proteins are extracted from cryptophyte algae and are investigated using steady-state and ultrafast spectroscopic techniques.

  3. Theoretical Studies of Spectroscopic Line Mixing in Remote Sensing Applications

    Science.gov (United States)

    Ma, Q.; Boulet, C.; Tipping, R. H.

    2015-01-01

    The phenomenon of collisional transfer of intensity due to line mixing has an increasing importance for atmospheric monitoring. From a theoretical point of view, all relevant information about the collisional processes is contained in the relaxation matrix where the diagonal elements give half-widths and shifts, and the off-diagonal elements correspond to line interferences. For simple systems such as those consisting of diatom-atom or diatom-diatom, accurate fully quantum calculations based on interaction potentials are feasible. However, fully quantum calculations become unrealistic for more complex systems. On the other hand, the semi-classical Robert-Bonamy (RB) formalism, which has been widely used to calculate half-widths and shifts for decades, fails in calculating the off-diagonal matrix elements. As a result, in order to simulate atmospheric spectra where the effects from line mixing are important, semi-empirical fitting or scaling laws such as the ECS (Energy-Corrected Sudden) and IOS (Infinite-Order Sudden) models are commonly used. Recently, while scrutinizing the development of the RB formalism, we have found that these authors applied the isolated line approximation in their evaluating matrix elements of the Liouville scattering operator given in exponential form. Since the criterion of this assumption is so stringent, it is not valid for many systems of interest in atmospheric applications. Furthermore, it is this assumption that blocks the possibility to calculate the whole relaxation matrix at all. By eliminating this unjustified application, and accurately evaluating matrix elements of the exponential operators, we have developed a more capable formalism. With this new formalism, we are now able not only to reduce uncertainties for calculated half-widths and shifts, but also to remove a once insurmountable obstacle to calculate the whole relaxation matrix. This implies that we can address the line mixing with the semi-classical theory based on

  4. The double-lined spectroscopic binary $\\alpha$ Andromedae orbital elements and elemental abundances

    CERN Document Server

    Ryabchikova, T A; Adelman, S J

    1998-01-01

    We performed a spectroscopic study of the SB2 Mercury-Manganese star alpha And. Our measurements of the secondary's radial velocities result in improved orbital elements. The secondary shows abundances typical of the metallic-line stars: a Ca deficiency, small overabundances of the iron-peak elements, and 1.0 dex overabundances of Sr and Ba.

  5. 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.

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

    Science.gov (United States)

    Simon, V.; Radu, T.; Vulpoi, A.; Rosca, C.; Eniu, D.

    2015-01-01

    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.

  7. 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.

  8. Spectroscopic Investigation of Ce(3+) Doped Fluoride Crystals

    Science.gov (United States)

    Reinhart, Donald H.; Armagan, Guzin; Marsh, Waverly; Barnes, James; Chai, B. H. T.

    1995-01-01

    Doping of the trivalent rare-earth cerium ion into fluoride crystals is of interest in producing turnable ultra-violet solid state lasers. These lasers are desirable for many applications in medicine, industry, and scientific research, including remote sensing. High absorption and stimulated emission cross sections of the dipole allowed 4f-5d transitions show promise in cerium as a laser ion in crystals. Several research groups have already reported the observation of stimulated emission of cerium in LiYF4, LiSrAlF6, and LiCaAlF6. However, the color center formation in the crystals due to the excited state absorption of ultra-violet pump light adds difficulty to achieving laser action. We have investigated the spectroscopic properties of cerium such as absorption and emission spectra, and lifetimes in four different fluoride crystals, including LiCaAlF6, LiSrAlF6, KyF4 and LiYF4. We have derived the polarized absorption and stimulated emission cross sections from transmission and fluorescence emission measurements for each of the host crystals. we have measured the lifetime of the lowest 5d level; moreover, investigated the temperature dependence of this lifetime and color center formation. Our results on absorption and stimulated emission cross sections for LiCaAlF6 and LiSrAlF6 are similar to the results already published.

  9. Spectroscopic and magnetic investigation of NiCo nanoferrites

    Energy Technology Data Exchange (ETDEWEB)

    Maqsood, Asghari, E-mail: tpl.qau@usa.net [Thermal Transport Laboratory, School of Chemical and Materials Engineering (SCME), National University of Sciences and Technology (NUST), H-12, Islamabad (Pakistan); Khan, Kishwar, E-mail: kishwar.nust@gmail.com [Thermal Transport Laboratory, School of Chemical and Materials Engineering (SCME), National University of Sciences and Technology (NUST), H-12, Islamabad (Pakistan); Anis-ur-Rehman, M.; Malik, M.A. [Applied Thermal Physics Laboratory, COMSATS Institute of Information Technology, Islamabad (Pakistan)

    2011-07-07

    Highlights: > Spinel ferrite is a special kind of cubic structure. > These ferrites are of great importance in electronics and communication industry. > These should be useful for high frequency applications. - Abstract: Spectroscopic and magnetic characterization of Ni{sub 1-x}Co{sub x}Fe{sub 2}O{sub 4} (0.0 {<=} x {<=} 0.5) nanoparticles is presented. The infrared spectra are measured in the frequency range 700-350 cm{sup -1}. Two prominent bands are observed, low frequency band at about 400 cm{sup -1} and high frequency band at about 600 cm{sup -1} assigned to octahedral and tetrahedral sites, respectively. The force constants K{sub o} and K{sub t} corresponding to octahedral and tetrahedral sites, respectively are also calculated from FTIR spectra. The effect of co-concentration on the magnetic properties has been investigated using a vibrating sample magnetometer (VSM). After appropriate treatments, it is found that both magnetic saturation (M{sub s}) and coercivities (H{sub c}) increase with co-concentration.

  10. Radiation Effects on Polypropylene Carbon Nanofibers Composites: Spectroscopic Investigations

    Science.gov (United States)

    Hamilton, John; Mion, Thomas; Cristian Chipara, Alin; Ibrahim, Elamin I.; Lozano, Karen; Tidrow, Steven; Magdalena Chipara, Dorina; Chipara, Mircea

    2010-03-01

    Dispersion of carbon nanostructures within polymeric matrices affects their physical and chemical properties (increased Young modulus, improved thermal stability, faster crystallization rates, higher equilibrium degree of crystallinity, modified glass, melting, and crystallization temperatures, enhanced thermal and electrical conductivity). Nevertheless, little is known about the radiation stability of such nanocomposites. The research is focused on spectroscopic investigations of radiation-induced modifications in isotactic polypropylene (iPP)-vapor grown nanofiber (VGCNF) composites. VGCNF were dispersed within iPP by extrusion at 180^oC. Composites containing various amounts of VGCNFs ranging from 0 to 20 % wt. were prepared and subjected to gamma irradiation, at room temperature, at various integral doses (10 MGy, 20 MGy, and 30 MGy). Raman spectroscopy, ATR, and WAXS were used to assess the radiation-induced modifications in these nanocomposites. Acknowledgements: This research was supported by the Welch Foundation (Department of Chemistry at UTPA), by Air Force Research Laboratory (FA8650-07-2-5061) and by US Army Research Laboratory/Office (W911NF-08-1-0353).

  11. The Sloan Digital Sky Survey Reverberation Mapping Project: Ensemble Spectroscopic Variability of Quasar Broad Emission Lines

    CERN Document Server

    Sun, Mouyuan; Shen, Yue; Brandt, W N; Dawson, Kyle; Denney, Kelly D; Hall, Patrick B; Ho, Luis C; Horne, Keith; Jiang, Linhua; Richards, Gordon T; Schneider, Donald P; Bizyaev, Dmitry; Kinemuchi, Karen; Oravetz, Daniel; Pan, Kaike; Simmons, Audrey

    2015-01-01

    We explore the variability of quasars in the MgII and Hbeta broad emission lines and UV/optical continuum emission using the Sloan Digital Sky Survey Reverberation Mapping project (SDSS-RM). This is the largest spectroscopic study of quasar variability to date: our study includes 29 spectroscopic epochs from SDSS-RM over $6$ months, containing 357 quasars with MgII and 41 quasars with Hbeta . On longer timescales, the study is also supplemented with two-epoch data from SDSS-I/II. The SDSS-I/II data include an additional $2854$ quasars with MgII and 572 quasars with Hbeta. The MgII emission line is significantly variable ($\\Delta f/f$ 10% on 100-day timescales), indicating that it is feasible to use the broad MgII line for reverberation mapping studies. The data also confirm that continuum variability increases with timescale and decreases with luminosity, and the continuum light curves are consistent with a damped random-walk model on rest-frame timescales of $\\gtrsim 5$ days. We compare the emission-line and...

  12. Molecular Hydrogen Emission Lines in Far Ultraviolet Spectroscopic Explorer Observations of Mira B

    CERN Document Server

    Wood, B E; Wood, Brian E.; Karovska, Margarita

    2004-01-01

    We present new Far Ultraviolet Spectroscopic Explorer (FUSE) observations of Mira A's wind-accreting companion star, Mira B. We find that the strongest lines in the FUSE spectrum are H2 lines fluoresced by H I Lyman-alpha. A previously analyzed Hubble Space Telescope (HST) spectrum also shows numerous Lyman-alpha fluoresced H2 lines. The HST lines are all Lyman band lines, while the FUSE H2 lines are mostly Werner band lines, many of them never before identified in an astrophysical spectrum. We combine the FUSE and HST data to refine estimates of the physical properties of the emitting H2 gas. We find that the emission can be reproduced by an H2 layer with a temperature and column density of T=3900 K and log N(H2)=17.1, respectively. Another similarity between the HST and FUSE data, besides the prevalence of H2 emission, is the surprising weakness of the continuum and high temperature emission lines, suggesting that accretion onto Mira B has weakened dramatically. The UV fluxes observed by HST on 1999 August ...

  13. Spectroscopic Investigation of a Repetitively-Pulsed Nanosecond Discharge

    Science.gov (United States)

    Yee, Benjamin T.

    This work reports on an investigation of a repetitively-pulsed nanosecond discharge (RPND) in helium over a range of 0.3-16.0 Torr. The discharge was studied experimentally via laser-absorption spectroscopy and opticals emission spectroscopy measurements. In concert with the experimental campaign, a global model of a helium plasma was developed with the aid of particle-in-cell simulations. The global model was then used to predict the population kinetics and emissions of the RPND. Synthesis of the results provided new data and insights on the development of the RPND. Among the results were direct measurements of the triplet metastable states during the excitation period. This period was found to be unexpectedly long at low pressures (less than or equal to 1.0 Torr), suggesting an excess in high-energy electrons as compared to an equilibrium distribution. Other phenomena such as a prominent return stroke and additional energy deposition by reflections in the transmission line were also identified. Estimates of the electric field and electron temperatures were obtained for several conditions. Furthermore, several optical methods for electron temperature measurement were evaluated for application to the discharge. Based on the global model simulations, the coronal model was found to apply to the line ratio of the 33S-23Po and 31S-2 1Po transitions, however further work is needed to ascertain its applicability to experimental discharges. These results provide new insight on the development of the repetitively-pulsed nanosecond discharge. Specifically, they reveal new information about the excited state dynamics within the discharge, the non-equilibrium nature of its electrons, and several avenues for future studies. This study extends the present understanding of repetitively-pulsed discharges, and advances the knowledge of energy coupling between electric fields and plasmas.

  14. The early-type strong emission-line supergiants of the Magellanic Clouds - A spectroscopic zoology

    Science.gov (United States)

    Shore, S. N.; Sanduleak, N.

    1984-01-01

    The results of a spectroscopic survey of 21 early-type extreme emission line supergiants of the Large and Small Magellanic Clouds using IUE and optical spectra are presented. The combined observations are discussed and the literature on each star in the sample is summarized. The classification procedures and the methods by which effective temperatures, bolometric magnitudes, and reddenings were assigned are discussed. The derived reddening values are given along with some results concerning anomalous reddening among the sample stars. The derived mass, luminosity, and radius for each star are presented, and the ultraviolet emission lines are described. Mass-loss rates are derived and discussed, and the implications of these observations for the evolution of the most massive stars in the Local Group are addressed.

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

    Energy Technology Data Exchange (ETDEWEB)

    Battie, Y., E-mail: yann.battie@univ-lorraine.fr [LCP-A2MC, Institut Jean Barriol, Université de Lorraine, 1 Bd Arago, 57070 Metz (France); Jamon, D. [Université de Lyon, Université Jean Monnet, EA 3523, Laboratoire Télécom Claude Chappe, 25 rue du Dr Rémy Annino, 42000 Saint Etienne (France); Lauret, J.S. [Laboratoire Aimé Cotton, UPR 3321, ENS Cachan, 94245 Cachan (France); Gu, Q.; Gicquel-Guézo, M. [FOTON, UMR 6082, INSA, Avenue des Buttes de Coësmes, 35043 Rennes (France); En Naciri, A. [LCP-A2MC, Institut Jean Barriol, Université de Lorraine, 1 Bd Arago, 57070 Metz (France); Loiseau, A. [Laboratoire d' étude des microstructures, ONERA-CNRS UMR 104, 29 Av. de la Division Leclerc, 92322 Chatillon (France)

    2014-11-28

    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{sub 11}, S{sub 22} and M{sub 11} transition energies. The transfer integral parameter γ{sub 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.

  16. A Far Ultraviolet Spectroscopic Explorer Survey of Coronal Forbidden Lines in Late-Type Stars

    CERN Document Server

    Redfield, S; Linsky, J L; Ake, T B; Dupree, A K; Robinson, R D; Young, P R; Redfield, Seth; Ayres, Thomas R.; Linsky, Jeffrey L.; Ake, Thomas B.; Robinson, Richard D.; Young, Peter R.

    2002-01-01

    We present a survey of coronal forbidden lines detected in Far Ultraviolet Spectroscopic Explorer (FUSE) spectra of nearby stars. Two strong coronal features, Fe XVIII 974 A and Fe XIX 1118 A, are observed in 10 of the 26 stars in our sample. Various other coronal forbidden lines, observed in solar flares, also were sought but not detected. The Fe XVIII feature, formed at log T (K) = 6.8, appears to be free of blends, whereas the Fe XIX line can be corrupted by a C I multiplet. FUSE observations of these forbidden iron lines at spectral resolution R ~ 15,000 provides the opportunity to study dynamics of hot coronal plasmas. We find that the velocity centroid of the Fe XVIII feature deviates little from the stellar rest frame, confirming that the hot coronal plasma is confined. The observed line widths generally are consistent with thermal broadening at the high temperatures of formation and show little indication of additional turbulent broadening. The fastest rotating stars, 31 Com, alpha Aur Ab, and AB Dor,...

  17. The Lick AGN Monitoring Project 2011: Spectroscopic Campaign and Emission-Line Light Curves

    CERN Document Server

    Barth, A J; Canalizo, G; Filippenko, A V; Gates, E L; Greene, J E; Li, W; Malkan, M A; Pancoast, A; Sand, D J; Stern, D; Treu, T; Woo, J -H; Assef, R J; Bae, H -J; Brewer, B J; Cenko, S B; Clubb, K I; Cooper, M C; Diamond-Stanic, A M; Hiner, K D; Hoenig, S F; Hsiao, E; Kandrashoff, M T; Lazarova, M S; Nierenberg, A M; Rex, J; Silverman, J M; Tollerud, E J; Walsh, J L

    2015-01-01

    In the Spring of 2011 we carried out a 2.5 month reverberation mapping campaign using the 3 m Shane telescope at Lick Observatory, monitoring 15 low-redshift Seyfert 1 galaxies. This paper describes the observations, reductions and measurements, and data products from the spectroscopic campaign. The reduced spectra were fitted with a multicomponent model in order to isolate the contributions of various continuum and emission-line components. We present light curves of broad emission lines and the AGN continuum, and measurements of the broad H-beta line widths in mean and root-mean square (rms) spectra. For the most highly variable AGNs we also measured broad H-beta line widths and velocity centroids from the nightly spectra. In four AGNs exhibiting the highest variability amplitudes, we detect anticorrelations between broad H-beta width and luminosity, demonstrating that the broad-line region "breathes" on short timescales of days to weeks in response to continuum variations. We also find that broad H-beta ve...

  18. Spectroscopic ellipsometric and Raman spectroscopic investigations of pulsed laser treated glassy carbon surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Csontos, J., E-mail: jcsontos@titan.physx.u-szeged.hu [University of Szeged, Department of Optics and Quantum Electronics, Dóm tér 9, H-6720 Szeged (Hungary); Pápa, Z.; Gárdián, A. [University of Szeged, Department of Optics and Quantum Electronics, Dóm tér 9, H-6720 Szeged (Hungary); Füle, M. [University of Szeged, Department of Experimental Physics, Dóm tér 9, H-6720 Szeged (Hungary); Budai, J. [University of Szeged, Department of Optics and Quantum Electronics, Dóm tér 9, H-6720 Szeged (Hungary); Toth, Z. [University of Szeged, Department of Optics and Quantum Electronics, Dóm tér 9, H-6720 Szeged (Hungary); University of Szeged, Department of Oral Biology and Experimental Dental Research, Tisza Lajos krt. 64, H-6720 Szeged (Hungary)

    2015-05-01

    Highlights: • Laser treatment modifies the top layer of glassy carbon as shown by ellipsometry. • Raman signal is composed from signals of the layer and the glassy carbon substrate. • Using volumetric fluence allows to compare the effects of different lasers. • Melting effects of glassy carbon was observed in case of Nd:YAG laser treatment. - Abstract: In this study spectroscopic ellipsometry (SE) and Raman spectroscopy are applied to study structural modification of glassy carbon, due to high intensity laser ablation. Two KrF lasers with different pulse durations (480 fs and 18 ns), an ArF (20 ns), and a frequency doubled Nd:YAG laser (8 ns) were applied to irradiate the surface of glassy carbon targets. The main characteristics of the different laser treatments are compared by introducing the volumetric fluence which takes into account the different absorption values at different wavelengths. SE showed the appearance of a modified layer on the ablated surfaces. In the case of the ns lasers the thickness of this layer was in the range of 10–60 nm, while in the case of fs laser it was less than 20 nm. In all cases the average refractive index (n) of the modified layers slightly decreased compared to the refractive index of glassy carbon. Increase in extinction coefficient (k) was observed in the cases of ArF and fs KrF laser treatment, while the k values decreased significantly in the cases of nanosecond pulse duration KrF and Nd:YAG laser treatments. In the Raman spectra of the ablated areas the characteristic D and G peaks were widened due to appearance of an amorphous phase. Both Raman spectroscopy and SE indicate that the irradiated areas show carbon nanoparticle formation in all cases.

  19. 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.

  20. Spectroscopic investigations on oxidized multi-walled carbon nanotubes

    Science.gov (United States)

    Anandhi, C. M. S.; Premkumar, S.; Asath, R. Mohamed; Mathavan, T.; Benial, A. Milton Franklin

    2016-05-01

    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-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.

  1. Measuring galaxy [OII] emission line doublet with future ground-based wide-field spectroscopic surveys

    CERN Document Server

    Comparat, Johan; Bacon, Roland; Mostek, Nick J; Newman, Jeffrey A; Schlegel, David J; Yèche, Christophe

    2013-01-01

    The next generation of wide-field spectroscopic redshift surveys will map the large-scale galaxy distribution in the redshift range 0.7< z<2 to measure baryonic acoustic oscillations (BAO). The primary optical signature used in this redshift range comes from the [OII] emission line doublet, which provides a unique redshift identification that can minimize confusion with other single emission lines. To derive the required spectrograph resolution for these redshift surveys, we simulate observations of the [OII] (3727,3729) doublet for various instrument resolutions, and line velocities. We foresee two strategies about the choice of the resolution for future spectrographs for BAO surveys. For bright [OII] emitter surveys ([OII] flux ~30.10^{-17} erg /cm2/s like SDSS-IV/eBOSS), a resolution of R~3300 allows the separation of 90 percent of the doublets. The impact of the sky lines on the completeness in redshift is less than 6 percent. For faint [OII] emitter surveys ([OII] flux ~10.10^{-17} erg /cm2/s like ...

  2. Line-Mixing Relaxation Matrix model for spectroscopic and radiative transfer studies

    Science.gov (United States)

    Mendaza, Teresa; Martin-Torres, Javier

    2016-04-01

    We present a generic model to compute the Relaxation Matrix easily adaptable to any molecule and type of spectroscopic lines or bands in non-reactive molecule collisions regimes. It also provides the dipole moment of every transition and level population of the selected molecule. The model is based on the Energy-Corrected Sudden (ECS) approximation/theory introduced by DePristo (1980), and on previous Relaxation Matrix studies for the interaction between molecular ro-vibrational levels (Ben-Rueven, 1966), atoms (Rosenkranz, 1975), linear molecules (Strow and Reuter, 1994; Niro, Boulet and Hartmann, 2004), and symmetric but not linear molecules (Tran et al., 2006). The model is open source, and it is user-friendly. To the point that the user only has to select the wished molecule and vibrational band to perform the calculations. It reads the needed spectroscopic data from the HIgh-resolution TRANsmission molecular absorption (HITRAN) (Rothman et al., 2013) and ExoMol (Tennyson and Yurchenko, 2012). In this work we present an example of the calculations with our model for the case of the 2ν3 band of methane (CH4), and a comparison with a previous work (Tran et al., 2010). The data produced by our model can be used to characterise the line-mixing effects on ro-vibrational lines of the infrared emitters of any atmosphere, to calculate accurate absorption spectra, that are needed in the interpretation of atmospheric spectra, radiative transfer modelling and General Circulation Models (GCM). References [1] A.E. DePristo, Collisional influence on vibration-rotation spectral line shapes: A scaling theoretical analysis and simplification, J. Chem. Phys. 73(5), 1980. [2] A. Ben-Reuven, Impact broadening of microwave spectra, Phys. Rev. 145(1), 7-22, 1966. [3] P.W. Rosenkranz, Shape of the 5 mm Oxygen Band in the Atmosphere, IEEE Transactions on Antennas and Propagation, vol. AP-23, no. 4, pp. 498-506, 1975. [4] Strow, L.L., D.D. Tobin, and S.E. Hannon, A compilation of

  3. The Lick AGN Monitoring Project 2011: Spectroscopic Campaign and Emission-line Light Curves

    Science.gov (United States)

    Barth, Aaron J.; Bennert, Vardha N.; Canalizo, Gabriela; Filippenko, Alexei V.; Gates, Elinor L.; Greene, Jenny E..; Li, Weidong; Malkan, Matthew A.; Pancoast, Anna; Sand, David J.; Stern, Daniel; Cenko, S. Bradley

    2016-01-01

    In the Spring of 2011 we carried out a 2.5 month reverberation mapping campaign using the 3 m Shane telescope at Lick Observatory, monitoring 15 low-redshift Seyfert 1 galaxies. This paper describes the observations, reductions and measurements, and data products from the spectroscopic campaign. The reduced spectra were fitted with a multicomponent model in order to isolate the contributions of various continuum and emission-line components. We present light curves of broad emission lines and the active galactic nucleus (AGN) continuum, and measurements of the broad Hß line widths in mean and rms spectra. For the most highly variable AGNs we also measured broad H beta line widths and velocity centroids from the nightly spectra. In four AGNs exhibiting the highest variability amplitudes, we detect anticorrelations between broad H beta width and luminosity, demonstrating that the broad-line region "breathes" on short timescales of days to weeks in response to continuum variations. We also find that broad H beta velocity centroids can undergo substantial changes in response to continuum variations; in NGC 4593, the broad H beta velocity shifted by approximately 250 km s(exp -1) over a 1 month period. This reverberation-induced velocity shift effect is likely to contribute a significant source of confusion noise to binary black hole searches that use multi-epoch quasar spectroscopy to detect binary orbital motion. We also present results from simulations that examine biases that can occur in measurement of broad-line widths from rms spectra due to the contributions of continuum variations and photon-counting noise.

  4. THE LICK AGN MONITORING PROJECT 2011: SPECTROSCOPIC CAMPAIGN AND EMISSION-LINE LIGHT CURVES

    Energy Technology Data Exchange (ETDEWEB)

    Barth, Aaron J. [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA, 92697-4575 (United States); Bennert, Vardha N. [Physics Department, California Polytechnic State University, San Luis Obispo, CA 93407 (United States); Canalizo, Gabriela [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Filippenko, Alexei V.; Li, Weidong [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Gates, Elinor L. [Lick Observatory, P.O. Box 85, Mount Hamilton, CA 95140 (United States); Greene, Jenny E. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Malkan, Matthew A.; Treu, Tommaso [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); Pancoast, Anna [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Sand, David J. [Texas Tech University, Physics Department, Box 41051, Lubbock, TX 79409-1051 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Boulevard, Pasadena, CA 91109 (United States); Woo, Jong-Hak [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Assef, Roberto J. [Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago (Chile); Bae, Hyun-Jin [Department of Astronomy and Center for Galaxy Evolution Research, Yonsei University, Seoul 120-749 (Korea, Republic of); Brewer, Brendon J. [Department of Statistics, The University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand); Cenko, S. Bradley [Astrophysics Science Division, NASA Goddard Space Flight Center, MC 661, Greenbelt, MD 20771 (United States); and others

    2015-04-15

    In the Spring of 2011 we carried out a 2.5 month reverberation mapping campaign using the 3 m Shane telescope at Lick Observatory, monitoring 15 low-redshift Seyfert 1 galaxies. This paper describes the observations, reductions and measurements, and data products from the spectroscopic campaign. The reduced spectra were fitted with a multicomponent model in order to isolate the contributions of various continuum and emission-line components. We present light curves of broad emission lines and the active galactic nucleus (AGN) continuum, and measurements of the broad Hβ line widths in mean and rms spectra. For the most highly variable AGNs we also measured broad Hβ line widths and velocity centroids from the nightly spectra. In four AGNs exhibiting the highest variability amplitudes, we detect anticorrelations between broad Hβ width and luminosity, demonstrating that the broad-line region “breathes” on short timescales of days to weeks in response to continuum variations. We also find that broad Hβ velocity centroids can undergo substantial changes in response to continuum variations; in NGC 4593, the broad Hβ velocity shifted by ∼250 km s{sup −1} over a 1 month period. This reverberation-induced velocity shift effect is likely to contribute a significant source of confusion noise to binary black hole searches that use multi-epoch quasar spectroscopy to detect binary orbital motion. We also present results from simulations that examine biases that can occur in measurement of broad-line widths from rms spectra due to the contributions of continuum variations and photon-counting noise.

  5. Studies of multiple stellar systems - IV. The triple-lined spectroscopic system Gliese 644

    CERN Document Server

    Mazeh, T; Goldberg, E; Torres, G L; Stefanik, R P; Henry, T J; Zucker, S W; Gnat, O; Ofek, E O; Mazeh, Tsevi; Latham, David W.; Goldberg, Elad; Torres, Guillermo; Stefanik, Robert P.; Henry, Todd J.; Zucker, Shay; Gnat, Orly; Ofek, Eran O.

    2001-01-01

    We present a radial-velocity study of the triple-lined system Gliese 644 and derive spectroscopic elements for the inner and outer orbits with periods of 2.9655 and 627 days. We also utilize old visual data, as well as modern speckle and adaptive optics observations, to derive a new astrometric solution for the outer orbit. These two orbits together allow us to derive masses for each of the three components in the system: M_A = 0.410 +/- 0.028 (6.9%), M_Ba = 0.336 +/- 0.016 (4.7%), and $M_Bb = 0.304 +/- 0.014 (4.7%) M_solar. We suggest that the relative inclination of the two orbits is very small. Our individual masses and spectroscopic light ratios for the three M stars in the Gliese 644 system provide three points for the mass-luminosity relation near the bottom of the Main Sequence, where the relation is poorly determined. These three points agree well with theoretical models for solar metallicity and an age of 5 Gyr. Our radial velocities for Gliese 643 and vB 8, two common-proper-motion companions of Gli...

  6. Reaching Higher Densities for Laboratory White Dwarf Photospheres to Measure Spectroscopic Line Profiles

    CERN Document Server

    Falcon, Ross E; Gomez, T A; Schaeuble, M; Nagayama, T; Montgomery, M H; Winget, D E; Rochau, G A

    2016-01-01

    As part of our laboratory investigation of the theoretical line profiles used in white dwarf atmosphere models, we extend the electron-density ($n_{\\rm e}$) range measured by our experiments to higher densities (up to $n_{e}\\sim80\\times10^{16}$ cm$^{-3}$). Whereas inferred parameters using the hydrogen-$\\beta$ spectral line agree among different line-shape models for $n_{\\rm e}\\lesssim30\\times10^{16}$ cm$^{-3}$, we now see divergence between models. These are densities beyond the range previously benchmarked in the laboratory, meaning theoretical profiles in this regime have not been fully validated. Experimentally exploring these higher densities enables us to test and constrain different line-profile models, as the differences in their relative H-Balmer line shapes are more pronounced at such conditions. These experiments also aid in our study of occupation probabilities because we can measure these from relative line strengths.

  7. Theoretical investigation of spectroscopic properties of $W^{25+}$

    CERN Document Server

    Alkauskas, A; Gaigalas, G; Kynienė, A; Kisielius, R; Kučas, S; Masys, Š; Merkelis, G; Jonauskas, V

    2015-01-01

    Energy levels and emission spectra of $W^{25+}$ ion have been studied by performing the large-scale relativistic configuration interaction calculations. Configuration interaction strength is used to determine the configurations exhibiting the largest influence on the $4f^{3}$, $4d^{9}4f^{4}$, $4f^{2}5s$, $4f^{2}5p$, $4f^{2}5d$, $4f^{2}5f$, $4f^{2}5g$, and $4f^{2}6g$ configuration energies. It is shown that correlation effects are crucial for the $4f^{2}5s \\rightarrow 4f^{3}$ transition which in single-configuration approach occurs due to the weak electric octupole transitions. As well, the correlation effects affect the $4f^{2}5d \\rightarrow 4f^{3}$ transitions by increasing transition probabilities by an order. Corona model has been used to estimate the contribution of various transitions to the emission in a low-density electron beam ion trap (EBIT) plasma. Modeling in 10--30 nm wavelength range produces lines which do not form emission bands and can be observed in EBIT plasma.

  8. Radiative transfer and spectroscopic databases: A line-sampling Monte Carlo approach

    Science.gov (United States)

    Galtier, Mathieu; Blanco, Stéphane; Dauchet, Jérémi; El Hafi, Mouna; Eymet, Vincent; Fournier, Richard; Roger, Maxime; Spiesser, Christophe; Terrée, Guillaume

    2016-03-01

    Dealing with molecular-state transitions for radiative transfer purposes involves two successive steps that both reach the complexity level at which physicists start thinking about statistical approaches: (1) constructing line-shaped absorption spectra as the result of very numerous state-transitions, (2) integrating over optical-path domains. For the first time, we show here how these steps can be addressed simultaneously using the null-collision concept. This opens the door to the design of Monte Carlo codes directly estimating radiative transfer observables from spectroscopic databases. The intermediate step of producing accurate high-resolution absorption spectra is no longer required. A Monte Carlo algorithm is proposed and applied to six one-dimensional test cases. It allows the computation of spectrally integrated intensities (over 25 cm-1 bands or the full IR range) in a few seconds, regardless of the retained database and line model. But free parameters need to be selected and they impact the convergence. A first possible selection is provided in full detail. We observe that this selection is highly satisfactory for quite distinct atmospheric and combustion configurations, but a more systematic exploration is still in progress.

  9. Spectroscopic measurements of a CO2 absorption line in an open vertical path using an airborne lidar

    CERN Document Server

    Ramanathan, Anand; Allan, Graham R; Riris, Haris; Weaver, Clark J; Hasselbrack, William E; Browell, Edward V; Abshire, James B

    2013-01-01

    We use an airborne pulsed integrated path differential absorption lidar to make spectroscopic measurements of the pressure-induced line broadening and line center shift of atmospheric CO2 at the 1572.335 nm absorption line. We measure the absorption lineshape in the vertical column between the aircraft and ground. A comparison of our measured absorption lineshape to calculations based on HITRAN shows excellent agreement with the peak optical depth accurate to within 0.3%. Additionally, we measure changes in the line center position to within 5.2 MHz of calculations, and the absorption linewidth to within 0.6% of calculations.

  10. Raman and surface enhanced Raman spectroscopic investigation on Lamiaceae plants

    Science.gov (United States)

    Rösch, P.; Popp, J.; Kiefer, W.

    1999-05-01

    The essential oils of Thymus vulgaris and Origanum vulgaris are studied by means of micro-Raman spectroscopy. The containing monoterpenes can be identified by their Raman spectra. Further the essential oils are investigated in their natural environment, the so-called oil cells of these Lamiaceae plants, with surface enhanced Raman spectroscopy (SERS). This method has the advantage to enhance Raman signals and furthermore the SERS effect leads to fluorescence quenching.

  11. Spectroscopic survey of emission-line stars. I. B[e] stars

    CERN Document Server

    Aret, Anna; Šlechta, Miroslav

    2015-01-01

    Emission-line stars are typically surrounded by dense circumstellar material, often in form of rings or disc-like structures. Line emission from forbidden transitions trace a diversity of density and temperature regimes. Of particular interest are the forbidden lines of [O I] {\\lambda}{\\lambda}6300, 6364 and [Ca II] {\\lambda}{\\lambda}7291, 7324. They arise in complementary, high-density environments, such as the inner-disc regions around B[e] supergiants. To study physical conditions traced by these lines and to investigate how common they are, we initiated a survey of emission-line stars. Here, we focus on a sample of nine B[e] stars in different evolutionary phases. Emission of the [O I] lines is one of the characteristics of B[e] stars. We find that four of the objects display [Ca II] line emission: for the B[e] supergiants V1478 Cyg and 3 Pup the kinematics obtained from the [O I] and [Ca II] line profiles agrees with a Keplerian rotating disc scenario; the forbidden lines of the compact planetary nebula ...

  12. Studies of multiple stellar systems - IV. The triple-lined spectroscopic system Gliese 644

    Science.gov (United States)

    Mazeh, Tsevi; Latham, David W.; Goldberg, Elad; Torres, Guillermo; Stefanik, Robert P.; Henry, Todd J.; Zucker, Shay; Gnat, Orly; Ofek, Eran O.

    2001-07-01

    We present a radial velocity study of the triple-lined system Gliese 644 and derive spectroscopic elements for the inner and outer orbits with periods of 2.9655 and 627d. We also utilize old visual data, as well as modern speckle and adaptive optics observations, to derive a new astrometric solution for the outer orbit. These two orbits together allow us to derive masses for each of the three components in the system: MA=0.410+/-0.028 (6.9 per cent), MBa=0.336+/-0.016 (4.7 per cent), and MBb=0.304+/-0.014 (4.7 per cent)Msolar. We suggest that the relative inclination of the two orbits is very small. Our individual masses and spectroscopic light ratios for the three M stars in the Gliese 644 system provide three points for the mass-luminosity relation near the bottom of the main sequence, where the relation is poorly determined. These three points agree well with theoretical models for solar metallicity and an age of 5Gyr. Our radial velocities for Gliese 643 and vB 8, two common proper motion companions of Gliese 644, support the interpretation that all five M stars are moving together in a physically bound group. We discuss possible scenarios for the formation and evolution of this configuration, such as the formation of all five stars in a sequence of fragmentation events leading directly to the hierarchical configuration now observed, versus formation in a small N cluster with subsequent dynamical evolution into the present hierarchical configuration.

  13. Characterization of GaSb-based heterostructures by spectroscopic investigations

    Energy Technology Data Exchange (ETDEWEB)

    Imhof, Sebastian; Bueckers, Christina; Metzger, Bjoern; Thraenhardt, Angela; Chatterjee, Sangam; Koch, Stephan W. [Fachbereich Physik, Wissenschaftliches Zentrum fuer Materialwissenschaften, Philipps Universitaet Marburg, Renthof 5, 35032 Marburg (Germany)

    2008-07-01

    The material system (AlGaIn)(AsSb) is suitable for laser emission at 2 {mu}m or longer wavelength, which is interesting for various applications, e.g. material processing, gas detection, medical diagnostic and laser surgery. A wide range of material combinations is being considered for application, but there are still uncertainties with regards to their structural properties, such as band alignment, strain and general bandstructure parameters. In order to gain information on these structural properties, we investigate GaSb-based heterostructures by modulation spectroscopy using e.g. photomodulated reflection. The experimental data are compared to simulations based on a microscopic theory.

  14. Raman spectroscopic investigation of blood and related materials

    Science.gov (United States)

    Gnyba, M.; Jedrzejewska-Szczerska, M.; Wróbel, M. S.

    2015-03-01

    This paper reports preliminary studies on use of Raman spectroscopy for investigation of blood. High quality blood spectra were recorded in-vitro with excitation wavelengths of 830 nm. Because of complex composition of the blood as well as by light attenuation and scattering in the tissues, spectra set up from wide, low-intensive Raman bands and intensive optical background. To get information about origin of bands in Raman spectra it is necessary to create phantom, which would show influence of this parameter and can be used to calibrate the Raman measurement system. Spectra of phantoms of selected blood components were acquired and discussed.

  15. Vibrational Spectroscopic and Thermodynamic Investigation of Poly (vinyl butyral

    Directory of Open Access Journals (Sweden)

    Saiful Islam Ansari

    2016-03-01

    Full Text Available A detailed study was performed to investigate the normal modes of vibration and their dispersions in poly (vinyl butyral by using Urey-Bradley force field and Wilson’s GF matrix method as modified by Higgs. It provides detailed interpretation of FTIR. Characteristic feature of dispersion curves such as regions of high density–of–states, repulsion and character mixing of dispersion modes are discussed. Predictive values of heat capacity as a function of temperature between 0-350 K have been evaluated.

  16. 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.

  17. Spectroscopic investigation of interaction between mangiferin and bovine serum albumin

    Science.gov (United States)

    Lin, Hui; Lan, Jingfeng; Guan, Min; Sheng, Fenling; Zhang, Haixia

    2009-09-01

    The mechanism of interaction between mangiferin (MA) and bovine serum albumin (BSA) in aqueous solution was investigated by fluorescence spectra, synchronous fluorescence spectra, absorbance spectra and Fourier transform infrared (FT-IR) spectroscopy. The binding constants and binding sites of MA to BSA at different reaction times were calculated. And the distance between MA and BSA was estimated to be 5.20 nm based on Föster's theory. In addition, synchronous fluorescence and FT-IR measurements revealed that the secondary structures of the protein changed after the interaction of MA with BSA. As a conclusion, the interaction between the anti-diabetes Chinese medicine MA and BSA may provide some significant information for the mechanism of the traditional chinese medicine MA on the protein level to cure diabetes or other diseases.

  18. Infrared Spectroscopic Investigation on CH Bond Acidity in Cationic Alkanes

    Science.gov (United States)

    Matsuda, Yoshiyuki; Xie, Min; Fujii, Asuka

    2016-06-01

    We have demonstrated large enhancements of CH bond acidities in alcohol, ether, and amine cations through infrared predissociation spectroscopy based on the vacuum ultraviolet photoionization detection. In this study, we investigate for the cationic alkanes (pentane, hexane, and heptane) with different alkyl chain lengths. The σ electrons are ejected in the ionization of alkanes, while nonbonding electrons are ejected in ionization of alcohols, ethers, and amines. Nevertheless, the acidity enhancements of CH in these cationic alkanes have also been demonstrated by infrared spectroscopy. The correlations of their CH bond acidities with the alkyl chain lengths as well as the mechanisms of their acidity enhancements will be discussed by comparison of infrared spectra and theoretical calculations.

  19. BAT AGN Spectroscopic Survey - III. An observed link between AGN Eddington ratio and narrow-emission-line ratios

    Science.gov (United States)

    Oh, Kyuseok; Schawinski, Kevin; Koss, Michael; Trakhtenbrot, Benny; Lamperti, Isabella; Ricci, Claudio; Mushotzky, Richard; Veilleux, Sylvain; Berney, Simon; Crenshaw, D. Michael; Gehrels, Neil; Harrison, Fiona; Masetti, Nicola; Soto, Kurt T.; Stern, Daniel; Treister, Ezequiel; Ueda, Yoshihiro

    2017-01-01

    We investigate the observed relationship between black hole mass (MBH), bolometric luminosity (Lbol) and Eddington ratio (λEdd) with optical emission-line ratios ([N II] λ6583/Hα, [S II] λλ6716, 6731/Hα, [O I] λ6300/Hα, [O III] λ5007/Hβ, [Ne III] λ3869/Hβ and He II λ4686/Hβ) of hard X-ray-selected active galactic nuclei (AGN) from the BAT AGN Spectroscopic Survey. We show that the [N II] λ6583/Hα ratio exhibits a significant correlation with λEdd (RPear = -0.44, p-value = 3 × 10-13, σ = 0.28 dex), and the correlation is not solely driven by MBH or Lbol. The observed correlation between [N II] λ6583/Hα ratio and MBH is stronger than the correlation with Lbol, but both are weaker than the λEdd correlation. This implies that the large-scale narrow lines of AGN host galaxies carry information about the accretion state of the AGN central engine. We propose that [N II] λ6583/Hα is a useful indicator of Eddington ratio with 0.6 dex of rms scatter, and that it can be used to measure λEdd and thus MBH from the measured Lbol, even for high-redshift obscured AGN. We briefly discuss possible physical mechanisms behind this correlation, such as the mass-metallicity relation, X-ray heating, and radiatively driven outflows.

  20. BAT AGN Spectroscopic Survey-III. An observed link between AGN Eddington ratio and narrow emission line ratios

    CERN Document Server

    Oh, Kyuseok; Koss, Michael; Trakhtenbrot, Benny; Lamperti, Isabella; Ricci, Claudio; Mushotzky, Richard; Veilleux, Sylvain; Berney, Simon; Crenshaw, D Michael; Gehrels, Neil; Harrison, Fiona; Masetti, Nicola; Soto, Kurt T; Stern, Daniel; Treister, Ezequiel; Ueda, Yoshihiro

    2016-01-01

    We investigate the observed relationship between black hole mass ($M_{\\rm BH}$), bolometric luminosity ($L_{\\rm bol}$), and Eddington ratio (${\\lambda}_{\\rm Edd}$) with optical emission line ratios ([NII] {\\lambda}6583/H{\\alpha}, [SII] {\\lambda}{\\lambda}6716,6731/H{\\alpha}, [OI] {\\lambda}6300/H{\\alpha}, [OIII] {\\lambda}5007/H{\\beta}, [NeIII] {\\lambda}3869/H{\\beta}, and HeII {\\lambda}4686/H{\\beta}) of hard X-ray-selected AGN from the BAT AGN Spectroscopic Survey (BASS). We show that the [NII] {\\lambda}6583/H{\\alpha} ratio exhibits a significant correlation with ${\\lambda}_{\\rm Edd}$ ($R_{\\rm Pear}$ = -0.44, $p$-value=$3\\times10^{-13}$, {\\sigma} = 0.28 dex), and the correlation is not solely driven by $M_{\\rm BH}$ or $L_{\\rm bol}$. The observed correlation between [NII] {\\lambda}6583/H{\\alpha} ratio and $M_{\\rm BH}$ is stronger than the correlation with $L_{\\rm bol}$, but both are weaker than the ${\\lambda}_{\\rm Edd}$ correlation. This implies that the large-scale narrow lines of AGN host galaxies carry informa...

  1. An Investigation of Sight-Line Stabilization

    Science.gov (United States)

    feedback control system that will accomplish sight-line stabilization is developed, and a numerical optimization is performed on a simplified version of this detailed model. The optimization routine used is described in reference.

  2. Spectroscopic investigation of thermal conductivity in few-layer graphene

    Science.gov (United States)

    Denison, Joseph C., Jr.

    Carbon is an extremely versatile element due to the ability of its electronic structure to allow strong bonds with many elements including other carbon atoms. This allows for the formation of many types of large and complex architectures, such as fullerenes and carbon nanotubes, at the nanoscale. One of the most fascinating allotropes of carbon is graphene, a two-dimensional honeycomb lattice with carbon in sp2 hybridization, which building block for layered graphite and other nanocarbons.[1] Because of its unique structure, graphene displays several interesting properties including high thermal[2-4] and electrical mobility and conductivity[1,5]. The initial studies on graphene were performed on mechanically exfoliated samples, which were limited to few microns in size. In the recent years, large areas of single- and few-layer graphene (˜few cm x cm) are being produced by chemical vapor deposition technique for practical applications. However, chemical vapor deposition grown graphene is highly polycrystalline with interfaces such as edges, grain boundaries, dislocations, and point defects. This inevitable presence of defects in graphene influences its electrical and thermal transport. While many studies have previously focused on the influence of defects on electrical mobility and conductivity, there is little information on the influence of defects on the thermal properties of graphene. This study specifically investigates the effect of both intrinsic and extrinsic defects on the in-plane thermal properties of graphene using micro-Raman spectroscopy. The in-plane thermal conductivity of few-layered graphene (FLG) was measured using Raman spectroscopy, following the work of Balandin et al. [4]The thermal conductivity was estimated from a shift of the characteristic G-band of graphene as a function of the excitation laser power. The graphene samples were synthesized on nickel substrates using chemical vapor deposition, and transferred to copper TEM grids and

  3. The magnetic field of the double-lined spectroscopic binary system HD 5550

    Science.gov (United States)

    Alecian, E.; Tkachenko, A.; Neiner, C.; Folsom, C. P.; Leroy, B.

    2016-05-01

    Context. The origin of fossil fields in intermediate- and high-mass stars is poorly understood, as is the interplay between binarity and magnetism during stellar evolution. Thus we have begun a study of the magnetic properties of a sample of intermediate-mass and massive short-period binary systems as a function of binarity properties. Aims: This paper specifically aims to characterise the magnetic field of HD 5550, a double-lined spectroscopic binary system of intermediate mass. Methods: We gathered 25 high-resolution spectropolarimetric observations of HD 5550 using the instrument Narval. We first fitted the intensity spectra using Zeeman/ATLAS9 LTE synthetic spectra to estimate the effective temperatures, microturbulent velocities, and the abundances of some elements of both components, as well as the light ratio of the system. We then applied the multi-line least-square deconvolution (LSD) technique to the intensity and circularly polarised spectra, which provided us with mean LSD I and V line profiles. We fitted the Stokes I line profiles to determine the radial and projected rotational velocities of both stars. We then analysed the shape and evolution of the V profiles using the oblique rotator model to characterise the magnetic fields of both stars. Results: We confirm the Ap nature of the primary, which has previously been reported, and find that the secondary displays spectral characteristics typical of an Am star. While a magnetic field is clearly detected in the lines of the primary, no magnetic field is detected in the secondary in any of our observations. If a dipolar field were present at the surface of the Am star, its polar strength must be below 40 G. The faint variability observed in the Stokes V profiles of the Ap star allowed us to propose a rotation period of 6.84-0.39+0.61 d, which is close to the orbital period (~6.82 d), suggesting that the star is synchronised with its orbit. By fitting the variability of the V profiles, we propose that the

  4. Investigating Starburst Galaxy Emission Line Equivalent Widths

    Science.gov (United States)

    Meskhidze, Helen; Richardson, Chris T.

    2016-01-01

    Modeling star forming galaxies with spectral synthesis codes allows us to study the gas conditions and excitation mechanisms that are necessary to reproduce high ionization emission lines in both local and high-z galaxies. Our study uses the locally optimally-emitting clouds model to develop an atlas of starburst galaxy emission line equivalent widths. Specifically, we address the following question: What physical conditions are necessary to produce strong high ionization emission lines assuming photoionization via starlight? Here we present the results of our photoionization simulations: an atlas spanning 15 orders of magnitude in ionizing flux and 10 orders of magnitude in hydrogen density that tracks over 150 emission lines ranging from the UV to the near IR. Each simulation grid contains ~1.5x104 photoionization models calculated by supplying a spectral energy distribution, grain content, and chemical abundances. Specifically, we will be discussing the effects on the emission line equivalent widths of varying the metallicity of the cloud, Z = 0.2 Z⊙ to Z = 5.0 Z⊙, and varying the star-formation history, using the instantaneous and continuous evolution tracks and the newly released Starburst99 Geneva rotation tracks.

  5. The magnetic field of the double-lined spectroscopic binary system HD 5550

    CERN Document Server

    Alecian, E; Neiner, C; Folsom, C P; Leroy, B

    2016-01-01

    (Abridged) In the framework of the BinaMicS project, we have begun a study of the magnetic properties of a sample of intermediate-mass and massive short-period binary systems, as a function of binarity properties. We report in this paper the characterisation of the magnetic field of HD 5550, a double-lined spectroscopic binary system of intermediate-mass, using high-resolution spectropolarimetric Narval observations of HD 5550. We first fit the intensity spectra using Zeeman/ATLAS9 LTE synthetic spectra to estimate the effective temperatures, microturbulent velocities, and the abundances of some elements of both components, as well as the light-ratio of the system. We then fit the least-square deconvolved $I$ profiles to determine the radial and projected rotational velocities of both stars. We then analysed the shape and evolution of the LSD $V$ profiles using the oblique rotator model to characterise the magnetic fields of both stars. We confirm the Ap nature of the primary, previously reported in the liter...

  6. Line narrowing spectroscopic studies of DNA-carcinogen adducts and DNA-dye complexes

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Myungkoo

    1995-12-06

    Laser-induced fluorescence line narrowing and non-line narrowing spectroscopic methods were applied to conformational studies of stable DNA adducts of the 7{beta}, 8{alpha}-dihydoxy-9{alpha}, l0{alpha}-epoxy-7,8,9, 10-tetrahydrobenzo[{alpha}]pyrene (anti-BPDE). Stereochemically distinct (+)-trans-, ({minus})-trans-, (+)-cis- and ({minus})-cis adducts of anti-BPDE bound to exocyclic amino group of the central guanine in an 11-mer oligonucleotide, exist in a mixture of conformations in frozen aqueous buffer matrices. The (+)-trans adduct adopts primarily an external conformation with a smaller fraction ( {approximately} 25 %) exists in a partially base-stacked conformation. Both cis adducts were found to be intercalated with significant {pi}-{pi} stacking interactions between the pyrenyl residues and the bases. Conformations of the trans-adduct of (+)-anti -BPDE in 11-mer oligonucleotides were studied as a function of flanking bases. In single stranded form the adduct at G{sub 2} or G{sub 3} (5 ft-flanking, base guanine) adopts a conformation with strong, interaction with the bases. In contrast, the adduct with a 5ft-flanking, thymine exists in a primarily helixexternal conformation. Similar differences were observed in the double stranded oligonucleotides. The nature of the 3ft-flanking base has little influence on the conformational equilibrium of the (+)-trans-anti BPDE-dG adduct. The formation and repair of BPDE-N{sup 2}-dG in DNA isolated from the skin of mice treated topically with benzo[{alpha}]pyrene (BP) was studied. Low-temperature fluorescence spectroscopy of the intact DNA identified the major adduct as (+)-trans-anti-BPDE-N-dG, and the minor adduct fraction consisted mainly of (+)-cis-anti-BPDE-N{sup 2}-dG.

  7. Line narrowing spectroscopic studies of DNA-carcinogen adducts and DNA-dye complexes

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Myungkoo [Iowa State Univ., Ames, IA (United States)

    1995-12-06

    Laser-induced fluorescence line narrowing and non-line narrowing spectroscopic methods were applied to conformational studies of stable DNA adducts of the 7β, 8α-dihydoxy-9α, l0α-epoxy-7,8,9, 10-tetrahydrobenzo[α]pyrene (anti-BPDE). Stereochemically distinct (+)-trans-, (-)-trans-, (+)-cis- and (-)-cis adducts of anti-BPDE bound to exocyclic amino group of the central guanine in an 11-mer oligonucleotide, exist in a mixture of conformations in frozen aqueous buffer matrices. The (+)-trans adduct adopts primarily an external conformation with a smaller fraction ( ~25 %) exists in a partially base-stacked conformation. Both cis adducts were found to be intercalated with significant π-π stacking interactions between the pyrenyl residues and the bases. Conformations of the trans-adduct of (+)-anti -BPDE in 11-mer oligonucleotides were studied as a function of flanking bases. In single stranded form the adduct at G2 or G3 (5 ft-flanking, base guanine) adopts a conformation with strong, interaction with the bases. In contrast, the adduct with a 5ft-flanking, thymine exists in a primarily helixexternal conformation. Similar differences were observed in the double stranded oligonucleotides. The nature of the 3ft-flanking base has little influence on the conformational equilibrium of the (+)-trans-anti BPDE-dG adduct. The formation and repair of BPDE-N2-dG in DNA isolated from the skin of mice treated topically with benzo[α]pyrene (BP) was studied. Low-temperature fluorescence spectroscopy of the intact DNA identified the major adduct as (+)-trans-anti-BPDE-N-dG, and the minor adduct fraction consisted mainly of (+)-cis-anti-BPDE-N2-dG.

  8. Spectral Line-Shape Model to Replace the Voigt Profile in Spectroscopic Databases

    Science.gov (United States)

    Lisak, Daniel; Ngo, Ngoc Hoa; Tran, Ha; Hartmann, Jean-Michel

    2014-06-01

    The standard description of molecular line shapes in spectral databases and radiative transfer codes is based on the Voigt profile. It is well known that its simplified assumptions of absorber free motion and independence of collisional parameters from absorber velocity lead to systematic errors in analysis of experimental spectra, and retrieval of gas concentration. We demonstrate1,2 that the partially correlated quadratic speed-dependent hardcollision profile3. (pCqSDHCP) is a good candidate to replace the Voigt profile in the next generations of spectroscopic databases. This profile takes into account the following physical effects: the Doppler broadening, the pressure broadening and shifting of the line, the velocity-changing collisions, the speed-dependence of pressure broadening and shifting, and correlations between velocity- and phase/state-changing collisions. The speed-dependence of pressure broadening and shifting is incorporated into the pCqSDNGP in the so-called quadratic approximation. The velocity-changing collisions lead to the Dicke narrowing effect; however in many cases correlations between velocityand phase/state-changing collisions may lead to effective reduction of observed Dicke narrowing. The hard-collision model of velocity-changing collisions is also known as the Nelkin-Ghatak model or Rautian model. Applicability of the pCqSDHCP for different molecular systems was tested on calculated and experimental spectra of such molecules as H2, O2, CO2, H2O in a wide span of pressures. For all considered systems, pCqSDHCP is able to describe molecular spectra at least an order of magnitude better than the Voigt profile with all fitted parameters being linear with pressure. In the most cases pCqSDHCP can reproduce the reference spectra down to 0.2% or better, which fulfills the requirements of the most demanding remote-sensing applications. An important advantage of pCqSDHCP is that a fast algorithm for its computation was developedab4,5 and allows

  9. A new massive double-lined spectroscopic binary system: The Wolf-Rayet star WR 68a

    Science.gov (United States)

    Collado, A.; Gamen, R.; Barbá, R. H.; Morrell, N.

    2015-09-01

    Double-lined spectroscopic binary systems, containing a Wolf-Rayet and a massive O-type star, are key objects for the study of massive star evolution because these kinds of systems allow the determination of fundamental astrophysical parameters of their components. We have performed spectroscopic observations of the star WR 68a as part of a dedicated monitoring program of WR stars to discover new binary systems. We identified spectral lines of the two components of the system and disentangled the spectra. We measured the radial velocities in the separated spectra and determined the orbital solution. We discovered that WR 68a is a double-lined spectroscopic binary with an orbital period of 5.2207 days, very small or null eccentricity, and inclination ranging between 75 and 85 deg. We classified the binary components as WN6 and O5.5-6. The WN star is less massive than the O-type star with minimum masses of 15 ± 5 M⊙ and 30 ± 4 M⊙, respectively. The equivalent width of the He ii λ4686 emission line shows variations with the orbital phase, presenting a minimum when the WN star is in front of the system. The light curve constructed from available photometric data presents minima in both conjunctions of the system. Table 2 is available in electronic form at http://www.aanda.org

  10. Effect of paramagnetic doping on an inorganic polymer triaquadipotassiumbis(malonato)zincate: spectroscopic investigation

    Science.gov (United States)

    Boobalan, S.; Sambasiva Rao, P.

    2011-01-01

    Spectroscopic investigations on Mn(II)-doped triaquadipotassiumbis(malonato)zincate [K2(H2O)3] [Zn(mal)2], an inorganic polymer, have been carried out at room temperature using single crystal electron paramagnetic resonance (EPR), ultraviolet-visible, FT-IR and powder XRD techniques. Single crystal rotations along the three orthogonal axes show more than 30 lines of patterns in EPR spectra, indicating the presence of two sites, one with a large D value and the other with a smaller D value. The calculated spin-Hamiltonian parameters are as follows. Site 1: g xx =2.099, g yy =2.092, g zz =1.988, A xx =9.77, A yy =9.71, A zz =8.96 mT, D xx =-29.09, D yy =-11.90, D zz =40.99 mT; Site 2: g xx =2.040, g yy =1.995, g zz =1.924, A xx =9.51, A yy =9.09, A zz =8.80 mT, D xx =-11.94, D yy =-7.51 and D zz =19.45 mT. The direction cosines of g/A/D do not match with the direction cosines of Zn-O bonds in the host lattice for either site, suggesting that both the Mn(II) sites entered the lattice interstitially. Optical results indicate a strong covalent bonding between the metal ion and ligands, with site symmetry being primarily octahedral. The FT-IR and powder XRD data confirm the retention of the crystal structure, even after incorporating a paramagnetic probe. Various admixture coefficients, bonding and optical parameters have also been calculated.

  11. A new massive double-lined spectroscopic binary system: The Wolf-Rayet star WR 68a

    CERN Document Server

    Collado, A; Barbá, R H; Morrell, N

    2015-01-01

    Double-lined spectroscopic binary systems, containing a Wolf-Rayet and a massive O-type star, are key objects for the study of massive star evolution because these kinds of systems allow the determination of fundamental astrophysical parameters of their components. We have performed spectroscopic observations of the star WR 68a as part of a dedicated monitoring program of WR stars to discover new binary systems. We identified spectral lines of the two components of the system and disentangled the spectra. We measured the radial velocities in the separated spectra and determined the orbital solution. We discovered that WR 68a is a double- lined spectroscopic binary with an orbital period of 5.2207 days, very small or null eccentricity, and inclination ranging between 75 and 85 deg. We classified the binary components as WN6 and O5.5-6. The WN star is less massive than the O-type star with minimum masses of 15 +/- 5 Msun and 30 +/- 4 Msun , respectively. The equivalent width of the He II {\\lambda}4686 emission ...

  12. BAT AGN Spectroscopic Survey II: X-ray Emission and High Ionization Optical Emission Lines

    CERN Document Server

    Berney, Simon; Trakhtenbrot, Benny; Ricci, Claudio; Lamperti, Isabella; Schawinski, Kevin; Balokovic, Mislav; Crenshaw, D Michael; Fischer, Travis; Gehrels, Neil; Harrison, Fiona; Hashimoto, Yasuhiro; Ichikawa, Kohei; Mushotzky, Richard; Oh, Kyuseok; Stern, Daniel; Treister, Ezequiel; Ueda, Yoshihiro; Veilleux, Sylvain; Winter, Lisa

    2015-01-01

    We investigate the relationship between X-ray and optical line emission in 340 nearby AGN selected above 10 keV using Swift BAT. We find a weak correlation between the extinction corrected [O III] and hard X-ray luminosity (14-195 keV) with a [OIII] large scatter (R_Pear = 0.64, sigma = 0.62 dex) and a similarly large scatter with the intrinsic 2-10 keV to [O III] luminosities (RPear=0.63, sigma = 0.63 dex). Correlations of the hard X-ray fluxes with the fluxes of high-ionization narrow lines ([O III], He II, [Ne III] and [Ne V]) are not significantly better than with the low ionization lines (Halpha, [SII]). Factors like obscuration or physical slit size are not found to be a significant part of the large scatter. In contrast, the optical emission lines show much better correlations with each other (sigma = 0.3 dex) than with the X-ray flux. The inherent large scatter questions the common usage of narrow emission lines as AGN bolometric luminosity indicators and suggests that other issues such as geometrical...

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

    Energy Technology Data Exchange (ETDEWEB)

    Wang Gongke, E-mail: wanggongke@126.com [School of Chemistry and Environmental Science, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, Xinxiang, Henan 453007 (China); Yan Changling; Wang Dongchao; Li Dan [School of Chemistry and Environmental Science, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, Xinxiang, Henan 453007 (China); Lu Yan, E-mail: yanlu2001@sohu.com [School of Chemistry and Environmental Science, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, Xinxiang, Henan 453007 (China)

    2012-07-15

    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{sup 4} M{sup -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: Black-Right-Pointing-Pointer Medically important dihydropyrimidinones derivative EMMD is synthesized. Black-Right-Pointing-Pointer EMMD is intercalative binding into ctDNA helix. Black-Right-Pointing-Pointer Hydrogen bonding may play an essential role in the binding of EMCD with ctDNA. Black-Right-Pointing-Pointer This binding interaction is predominantly enthalpy driven.

  14. Line parameter study of ozone at 5 and 10 μm using atmospheric FTIR spectra from the ground: A spectroscopic database and wavelength region comparison

    Science.gov (United States)

    Janssen, Christof; Boursier, Corinne; Jeseck, Pascal; Té, Yao

    2016-08-01

    Atmospheric ozone concentration measurements mostly depend on spectroscopic methods that cover different spectral regions. Despite long years of measurement efforts, the uncertainty goal of 1% in absolute line intensities has not yet been reached. Multispectral inter-comparisons using both laboratory and atmospheric studies reveal that important discrepancies exist when ozone columns are retrieved from different spectral regions. Here, we use ground based FTIR to study the sensitivity of ozone columns on different spectroscopic parameters as a function of individual bands for identifying necessary improvements of the spectroscopic databases. In particular, we examine the degree of consistency that can be reached in ozone retrievals using spectral windows in the 5 and 10 μm bands of ozone. Based on the atmospheric spectra, a detailed database inter-comparison between HITRAN (version 2012), GEISA (version 2011) and S&MPO (as retrieved from the website at the end of 2015) is made. Data from the 10 μm window are consistent to better than 1%, but there are larger differences when the windows at 5 μm are included. The 5 μm results agree with the results from 10 μm within ±2% for all databases. Recent S&MPO data are even more consistent with the desired level of 1%, but spectroscopic data from HITRAN give about 4% higher ozone columns than those from GEISA. If four sub-windows in the 5 μm band are checked for consistency, retrievals using GEISA or S&MPO parameters show less dispersion than those using HITRAN, where one window in the P-branch of the ν1 + ν3 band gives about 2% lower results than the other three. The atmospheric observations are corroborated by a direct comparison of the spectroscopic databases, using a simple statistical analysis based on intensity weighted spectroscopic parameters. The bias introduced by the weighted average approach is investigated and it is negligible if relative differences between databases do not correlate with line

  15. Investigating the Spectroscopic Variability and Magnetic Activity of Photometrically Variable M Dwarfs in SDSS

    Science.gov (United States)

    Ventura, Jean-Paul; Cid, Aurora; Schmidt, Sarah J.; Rice, Emily L.; Cruz, Kelle L.

    2017-01-01

    Magnetic activity, a wide range of observable phenomena produced in the outer atmospheres of stars, is currently not well understood for M dwarfs. In higher mass stars, magnetic activity is powered by a dynamo process involving the differential rotation of a star’s inner regions. This process generates a magnetic field, heats up regions in the atmosphere, and produces emission line radiation (H-alpha) from collisional excitation. Using the Sloan Digital Sky Survey’s (SDSS) Time Domain Spectroscopic Survey (TDSS), we will compare the H-alpha emission line strengths for a sample of 12,000 known photometrically variable M dwarfs observed in the PAN-STARRS1 survey with those of a known non-variable sample. This will be done in order to test whether photometric variability of the sample correlate with chromospheric H-alpha emission features and if not, explore the alternate reasons for that photometric variability, like binarity.

  16. Development of On-Line Spectroscopic pH Monitoring for Nuclear Fuel Reprocessing Plants: Weak Acid Schemes

    Energy Technology Data Exchange (ETDEWEB)

    Casella, Amanda J.; Hylden, Laura R.; Campbell, Emily L.; Levitskaia, Tatiana G.; Peterson, James M.; Smith, Frances N.; Bryan, Samuel A.

    2015-05-19

    Knowledge of real-time solution properties and composition is a necessity for any spent nuclear fuel reprocessing method. Metal-ligand speciation in aqueous solutions derived from the dissolved commercial spent fuel is highly dependent upon the acid concentration/pH, which influences extraction efficiency and the resulting speciation in the organic phase. Spectroscopic process monitoring capabilities, incorporated in a counter current centrifugal contactor bank, provide a pathway for on-line real-time measurement of solution pH. The spectroscopic techniques are process-friendly and can be easily configured for on-line applications, while classic potentiometric pH measurements require frequent calibration/maintenance and have poor long-term stability in aggressive chemical and radiation environments. Our research is focused on developing a general method for on-line determination of pH of aqueous solutions through chemometric analysis of Raman spectra. Interpretive quantitative models have been developed and validated under the range of chemical composition and pH using a lactic acid/lactate buffer system. The developed model was applied to spectra obtained on-line during solvent extractions performed in a centrifugal contactor bank. The model predicted the pH within 11% for pH > 2, thus demonstrating that this technique could provide the capability of monitoring pH on-line in applications such as nuclear fuel reprocessing.

  17. Microscopic and Spectroscopic Investigation of Poly(3-hexylthiophene Interaction with Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Maurizio De Crescenzi

    2011-08-01

    Full Text Available The inclusion of carbon nanotubes in polymer matrix has been proposed to enhance the polymer’s physical and electrical properties. In this study, microscopic and spectroscopic techniques are used to investigate the interaction between poly(3-hexylthiophene (P3HT and nanotubes and the reciprocal modification of physical properties. The presence of P3HT-covered nanotubes dispersed in the polymer matrix has been observed by atomic force microscopy and transmission electron microscopy. Then, the modification of P3HT optical properties due to nanotube inclusion has been evidenced with spectroscopic techniques like absorption and Raman spectroscopy. The study is completed with detailed nanoscale analysis by scanning probe techniques. The ordered self assembly of polymer adhering on the nanotube is unveiled by showing an example of helical wrapping of P3HT. Scanning tunneling spectroscopy study provides information on the electronic structure of nanotube-polymer assembly, revealing the charge transfer from P3HT to the nanotube.

  18. M-line spectroscopic, spectroscopic ellipsometric and microscopic measurements of optical waveguides fabricated by MeV-energy N{sup +} ion irradiation for telecom applications

    Energy Technology Data Exchange (ETDEWEB)

    Bányász, I., E-mail: banyasz@sunserv.kfki.hu [Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O.B. 49, H-1525, Budapest (Hungary); Berneschi, S. [“Enrico Fermi” Center for Study and Research, Piazza del Viminale 2, 00184 Roma (Italy); MDF-Lab, “Nello Carrara” Institute of Applied Physics, IFAC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Fried, M.; Lohner, T. [Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O.B. 49, H-1525, Budapest (Hungary); Conti, G. Nunzi; Righini, G.C.; Pelli, S. [MDF-Lab, “Nello Carrara” Institute of Applied Physics, IFAC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Zolnai, Z. [Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O.B. 49, H-1525, Budapest (Hungary)

    2013-08-31

    Irradiation with N{sup +} ions of the 1.5–3.5 MeV energy range was applied to optical waveguide formation. Planar and channel waveguides have been fabricated in an Er-doped tungsten–tellurite glass, and in both types of bismuth germanate (BGO) crystals: Bi{sub 4}Ge{sub 3}O{sub 12} (eulytine) and Bi{sub 12}GeO{sub 20} (sillenite). Multi-wavelength m-line spectroscopy and spectroscopic ellipsometry were used for the characterisation of the ion beam irradiated waveguides. Planar waveguides fabricated in the Er-doped tungsten–tellurite glass using irradiation with N{sup +} ions at 3.5 MeV worked even at the 1550 nm telecommunication wavelength. 3.5 MeV N{sup +} ion irradiated planar waveguides in eulytine-type BGO worked up to 1550 nm and those in sillenite-type BGO worked up to 1330 nm. - Highlights: ► Waveguides were fabricated in glass and crystals using MeV energy N{sup +} ions. ► SRIM simulation and spectroscopic ellipsometry yielded similar waveguide structures. ► Multi-wavelength m-line spectroscopy was used to study the waveguides. ► Waveguides fabricated in an Er-doped tungsten–tellurite glass worked up to 1.5 μm. ► Waveguides in Bi{sub 12}GeO{sub 20} remained operative up to 1.5 μm.

  19. VLT-UVES observations of the Balmer line variations of eta Carinae during the 2003 spectroscopic event

    CERN Document Server

    Weis, K; Bomans, D J; Davidson, K; Gull, T R; Humphreys, R M; Weis, Kerstin; Stahl, Otmar; Bomans, Dominik J.; Davidson, Kris; Gull, Theodore R.; Humphreys, Roberta M.

    2004-01-01

    We present high spectral resolution echelle observations of the Balmer line variations during the 2003.5 ``spectroscopic event'' of eta Carinae. Spectra have been recorded of both eta Carinae and the Homunculus at the FOS4 position in its SE lobe. This spot shows a reflected stellar spectrum which is less contaminated by nebular emission lines than ground-based observations of the central object itself. Our observations show that the spectroscopic event is much less pronounced at this position than when seen directly on eta Car using HST/STIS. Assuming that the reflected spectrum is indeed latitude dependent this indicates that the spectral changes during the event seen pole-on (FOS4) are different from those closer to the equator (directly on the star). In contrast to the spectrum of the star, the scattered spectrum of FOS4 always shows pronounced P Cygni absorption with little variation across the ``spectroscopic event''. After that event an additional high-velocity absorption component appears. The emissio...

  20. The SDSS-IV extended Baryon Oscillation Spectroscopic Survey: selecting emission line galaxies using the Fisher discriminant

    Science.gov (United States)

    Raichoor, A.; Comparat, J.; Delubac, T.; Kneib, J.-P.; Yèche, Ch.; Zou, H.; Abdalla, F. B.; Dawson, K.; de la Macorra, A.; Fan, X.; Fan, Z.; Jiang, Z.; Jing, Y.; Jouvel, S.; Lang, D.; Lesser, M.; Li, C.; Ma, J.; Newman, J. A.; Nie, J.; Palanque-Delabrouille, N.; Percival, W. J.; Prada, F.; Shen, S.; Wang, J.; Wu, Z.; Zhang, T.; Zhou, X.; Zhou, Z.

    2016-01-01

    We present a new selection technique of producing spectroscopic target catalogues for massive spectroscopic surveys for cosmology. This work was conducted in the context of the extended Baryon Oscillation Spectroscopic Survey (eBOSS), which will use ~200 000 emission line galaxies (ELGs) at 0.6 ≤ zspec ≤ 1.0 to obtain a precise baryon acoustic oscillation measurement. Our proposed selection technique is based on optical and near-infrared broad-band filter photometry. We used a training sample to define a quantity, the Fisher discriminant (linear combination of colours), which correlates best with the desired properties of the target: redshift and [Oii] flux. The proposed selections are simply done by applying a cut on magnitudes and this Fisher discriminant. We used public data and dedicated SDSS spectroscopy to quantify the redshift distribution and [Oii] flux of our ELG target selections. We demonstrate that two of our selections fulfil the initial eBOSS/ELG redshift requirements: for a target density of 180 deg-2, ~70% of the selected objects have 0.6 ≤ zspec ≤ 1.0 and only ~1% of those galaxies in the range 0.6 ≤ zspec ≤ 1.0 are expected to have a catastrophic zspec estimate. Additionally, the stacked spectra and stacked deep images for those two selections show characteristic features of star-forming galaxies. The proposed approach using the Fisher discriminant could, however, be used to efficiently select other galaxy populations, based on multi-band photometry, providing that spectroscopic information isavailable. This technique could thus be useful for other future massive spectroscopic surveys such as PFS, DESI, and 4MOST.

  1. Raman spectroscopic investigation of thorium dioxide-uranium dioxide (ThO₂-UO₂) fuel materials.

    Science.gov (United States)

    Rao, Rekha; Bhagat, R K; Salke, Nilesh P; Kumar, Arun

    2014-01-01

    Raman spectroscopic investigations were carried out on proposed nuclear fuel thorium dioxide-uranium dioxide (ThO2-UO2) solid solutions and simulated fuels based on ThO2-UO2. Raman spectra of ThO2-UO2 solid solutions exhibited two-mode behavior in the entire composition range. Variations in mode frequencies and relative intensities of Raman modes enabled estimation of composition, defects, and oxygen stoichiometry in these compounds that are essential for their application. The present study shows that Raman spectroscopy is a simple, promising analytical tool for nondestructive characterization of this important class of nuclear fuel materials.

  2. Electron spectroscopic investigation of metal-insulator transition in Ce1-SrTiO3

    Indian Academy of Sciences (India)

    U Manju; S R Krishnakumar; Sugata Ray; S Raj; M Onoda; C Carbone; D D Sarma

    2003-10-01

    We have carried out detailed electron spectroscopic investigation of Ce1-SrTiO3 exhibiting insulator-metal transition with . Core level X-ray photoelectron spectra of Ce 3 as well as resonant photoemission spectra obtained at the Ce 4 → 4 resonant absorption threshold establish Ce as being in the trivalent state throughout the series. Using the `off-resonance’ condition for Ce 4 states, we obtain the Ti 3 dominated spectral features close to , exhibiting clear signatures of coherent and incoherent peaks. We discuss the implications of our findings in relation to the metal-insulator transition observed in this series of compounds.

  3. 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.

  4. The SDSS-IV extended Baryonic Oscillation Spectroscopic Survey: selecting Emission Line Galaxies using the Fisher Discriminant

    CERN Document Server

    Raichoor, A; Delubac, T; Kneib, J -P; Yèche, C; Zou, H; Abdalla, F B; Dawson, K; Fan, X; Fan, Z; Jiang, Z; Jing, Y; Jouvel, S; Lang, D; Lesser, M; Li, C; Ma, J; Newman, J A; Nie, J; Olszewski, E; Palanque-Delabrouille, N; Percival, W; Prada, F; Shen, S; Wang, J; Wu, Z; Zhang, T; Zhou, X; Zhou, Z

    2015-01-01

    We present a new selection technique to produce spectroscopic target catalogues for massive spectroscopic surveys for cosmology. This work was conducted in the context of the extended Baryon Oscillation Spectroscopic Survey (eBOSS), which will use 200,000 emission line galaxies (ELGs) at 0.6

  5. Investigation of soil salinity to distinguish boundary line between ...

    African Journals Online (AJOL)

    Investigation of soil salinity to distinguish boundary line between saline and agricultural ... Plain which is one of the important agricultural production centers in the area. Therefore, careful monitoring of lands near salinity boundary in the area ...

  6. Pr(Ⅲ) and Nd(Ⅲ) Absorption Spectroscopic Probe to Investigate Interaction with Lysozyme (HEW)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Pr(Ⅲ) and Nd(Ⅲ) can be utilized as absorption spectroscopic probes to investigate the interaction of biomolecules like Lysozyme (HEW) with Ca(Ⅱ) in-vitro; the most abundant metal ion in the human body system. The spectroscopic techniques involving comparative absorption, absorption difference, and quantitative intensity analysis using 4f-4f transitions are utilized for changes in the inner sphere coordination pattern of Pr(Ⅲ) and Nd(Ⅲ) in solution as well as in solid state. The present study deals with an important biomolecule in human metabolism, that is, Lysozyme (HEW). The absorption spectral parameters such as the oscillator strength (P), the Judd-Ofelt (Tλ) intensity parameters, and the Slater-Condon inter electronic parameters are calculated using chi square methods. The obtained results are used to determine the probable geometry of the complex in the solution, the nature of the bond between Pr(Ⅲ)/Nd(Ⅲ) with lysozyme, and the inner sphere coordination environment of f-f transitions. The results obtained from various experimental conditions are utilized to investigate the coordination changes in the Pr(Ⅲ)/Nd(Ⅲ) complexes caused by different coordinating sites of lysozyme, normalized bite, denticity, the solvent nature, the coordination number, the nature of bond and other parameters to mimic the interaction of the Ca(Ⅱ) ion with such biomolecule.

  7. The smooth cyclotron line in her x-1 as seen with nuclear spectroscopic telescope array

    DEFF Research Database (Denmark)

    Fuerst, Felix; Grefenstette, Brian W.; Staubert, Ruediger;

    2013-01-01

    Her X-1, one of the brightest and best studied X-ray binaries, shows a cyclotron resonant scattering feature (CRSF) near 37 keV. This makes it an ideal target for detailed study with the Nuclear Spectroscopic Telescope Array (NuSTAR), taking advantage of its excellent hard X-ray spectral resoluti...... in the hot corona of the accretion disk. The average, luminosity-corrected CRSF energy is lower than in past observations and follows a secular decline. The excellent data quality of NuSTAR provides the best constraint on the CRSF energy to date.......Her X-1, one of the brightest and best studied X-ray binaries, shows a cyclotron resonant scattering feature (CRSF) near 37 keV. This makes it an ideal target for detailed study with the Nuclear Spectroscopic Telescope Array (NuSTAR), taking advantage of its excellent hard X-ray spectral resolution...

  8. Investigation of the selenium metabolism in cancer cell lines

    DEFF Research Database (Denmark)

    Lunøe, Kristoffer; Gabel-Jensen, Charlotte; Stürup, Stefan

    2011-01-01

    incubated with cells for 24 h and the induction of cell death was measured using flow cytometry. The amounts of total selenium in cell medium, cell lysate and the insoluble fractions was determined by ICP-MS. Speciation analysis of cellular fractions was performed by reversed phase, anion exchange and size......The aim of this work was to compare different selenium species for their ability to induce cell death in different cancer cell lines, while investigating the underlying chemistry by speciation analysis. A prostate cancer cell line (PC-3), a colon cancer cell line (HT-29) and a leukaemia cell line...... exclusion chromatography and ICP-MS detection. The selenium compounds exhibited large differences in their ability to induce cell death in the three cell lines and the susceptibilities of the cell lines were different. Full recovery of selenium in the cellular fractions was observed for all Se compounds...

  9. Spectroscopic investigations on thin adhesive layers in multi-material laminates.

    Science.gov (United States)

    Voronko, Yuliya; Chernev, Boril S; Eder, Gabriele C

    2014-01-01

    Three different spectroscopic approaches, Raman linescans, Raman imaging, and attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) imaging were evaluated for the visualization of the thin adhesive layers (3-6 μm) present in polymeric photovoltaic backsheets. The cross-sections of the multilayer laminates in the original, weathered, and artificially aged samples were investigated spectroscopically in order to describe the impact of the environmental factors on the evenness and thickness of the adhesive layers. All three methods were found to be suitable tools to detect and visualize these thin layers within the original and aged polymeric laminates. However, as the adhesive layer is not very uniform in thickness and partly disintegrates upon weathering and/or artificial aging, Raman linescans yield only qualitative information and do not allow for an estimation of the layer thickness. Upon increasing the measuring area by moving from one-dimensional linescans to two-dimensional Raman images, a much better result could be achieved. Even though a longer measuring time has to be taken into account, the information on the uniformity and evenness of the adhesive layer obtainable using the imaging technique is much more comprehensive. Although Raman spectroscopy is known to have the superior lateral resolution as compared with ATR FT-IR spectroscopy, the adhesive layers of the samples used within this study (layer thickness 3-6 μm) could also be detected and visualized by applying the ATR FT-IR spectroscopic imaging method. However, the analysis of the images was quite a demanding task, as the thickness of the adhesive layer was in the region of the resolution limit of this method. The information obtained for the impact of artificial aging and weathering on the adhesive layer obtained using Raman imaging and ATR FT-IR imaging was in good accordance.

  10. 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.

  11. Structural and mechanical properties of cellulose acetate/graphene hybrid nanofibers: Spectroscopic investigations

    Directory of Open Access Journals (Sweden)

    B. S. Kim

    2013-06-01

    Full Text Available Cellulose acetate/graphene (CA/graphene and cellulose acetate/graphene-COOH (CA/graphene-COOH hybrid nanofibers were fabricated via electrospinning technique, and their morphologies, crystallinity and mechanical properties were investigated. The added amounts of graphene and graphene-COOH were varied from 0.5 to 5.0 wt%. The crystal structures and morphologies of the resultant hybrid nanofibers were investigated by wide angle X-ray diffraction (WAXD, scanning electron microscopy (SEM and transmission electron microscopy (TEM, respectively. Graphene-COOH incorporated CA nanofiber mats showed higher Young’s modulus of about 910 MPa among than those of CA/graphene nanofibers, which is due to molecular interactions between –COOH groups in acid-treated graphene and C=O groups in CA via hydrogen bonding. This specific interaction was demonstrated by spectroscopic studies (Raman and Fourier transform infrared (FT-IR spectroscopies.

  12. Synthesis, structure, spectroscopic investigations, and computational studies of optically pure β-ketoamide

    Science.gov (United States)

    Mtat, D.; Touati, R.; Guerfel, T.; Walha, K.; Ben Hassine, B.

    2016-12-01

    Chemical preparation, X-ray single crystal diffraction, IR and NMR spectroscopic investigations of a novel nonlinear optical organic compound (C17H22NO2Cl) are described. The compound crystallizes in the orthorhombic system with the non-centrosymmetric sp. gr. P212121. 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 βtot of the title compound is determined using DFT calculations. The optical properties are also investigated by UV-Vis absorption spectrum.

  13. A spectroscopic analysis of a sample of narrow-line Seyfert 1 galaxies selected from the Sloan Digital Sky Survey

    Science.gov (United States)

    Cracco, V.; Ciroi, S.; Berton, M.; Di Mille, F.; Foschini, L.; La Mura, G.; Rafanelli, P.

    2016-10-01

    We revisited the spectroscopic characteristics of narrow-line Seyfert 1 galaxies (NLS1s) by analysing a homogeneous sample of 296 NLS1s at redshift between 0.028 and 0.345, extracted from the Sloan Digital Sky Survey (SDSS-DR7) public archive. We confirm that NLS1s are mostly characterized by Balmer lines with Lorentzian profiles, lower black hole masses and higher Eddington ratios than classic broad-line Seyfert 1 (BLS1s), but they also appear to be active galactic nuclei (AGNs) contiguous with BLS1s and sharing with them common properties. Strong Fe II emission does not seem to be a distinctive property of NLS1s, as low values of Fe II/Hβ are equally observed in these AGNs. Our data indicate that Fe II and Ca II kinematics are consistent with the one of Hβ. On the contrary, O I λ8446 seems to be systematically narrower and it is likely emitted by gas of the broad-line region more distant from the ionizing source and showing different physical properties. Finally, almost all NLS1s of our sample show radial motions of the narrow-line region highly ionized gas. The mechanism responsible for this effect is not yet clear, but there are hints that very fast outflows require high continuum luminosities (>1044 erg s-1) or high Eddington ratios (log (Lbol/LEdd) > -0.1).

  14. Synthesis and spectroscopic investigation of nanostructured europium oxalate: A potential red emitting phosphor

    Science.gov (United States)

    Vimal, G.; Mani, K. P.; Biju, P. R.; Joseph, C.; Unnikrishnan, N. V.; Ittyachen, M. A.

    2015-10-01

    Nanostructured europium oxalate was successfully synthesized for the first time by microwave assisted co-precipitation method. Structure and nanocrystalline nature of the synthesized europium oxalate was analyzed using X-ray diffraction and the results were confirmed by transmission electron microscopy. Fourier transform infrared spectroscopy was employed to identify the different functional groups present in the nanostructured europium oxalate. Detailed spectroscopic investigations were carried out using Judd-Ofelt theory to find out the spectroscopic parameters of europium oxalate. Nature of the metal-ligand bond and symmetry of the environment around Eu3+ ions, which strongly influences the luminescence characteristics of the material, were analyzed. Photoluminescence emission spectrum of the material confirmed the strong red emission predicted by the JO theoretical analysis which is further ascertained by CIE chromaticity diagram. Further analysis on the luminescence parameters such as life time, quantum efficiency and color purity of nanostructured europium oxalate revealed the suitability of this material as a potential phosphor for red emission.

  15. 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.

  16. The quest for collapsed/frozen stars in single-line spectroscopic binary systems

    Science.gov (United States)

    Trimble, Virginia

    2016-10-01

    Black holes are now commonplace, among the stars, in Galactic centers, and perhaps other places. But within living memory, their very existence was doubted by many, and few chose to look for them. Zeldovich and Guseinov were first, followed by Trimble and Thorne, using a method that would have identified HDE 226868 as a plausible candidate, if it had been in the 1968 catalogue of spectroscopic binaries. That it was not arose from an unhappy accident in the observing program of Daniel M. Popper long before the discovery of X-ray binaries and the identification of Cygnus X-1 with that hot, massive star and its collapsed companion.

  17. The quest for collapsed/frozen stars in single-line spectroscopic binary systems

    CERN Document Server

    Trimble, Virginia

    2014-01-01

    Black holes are now commonplace, among the stars, in Galactic centers, and perhaps other places. But within living memory, their very existence was doubted by many, and few chose to look for them. Zeldovich and Guseinov were first, followed by Trimble and Thorne, using a method that would have identified HDE 226868 as a plausible candidate, if it had been in the 1968 catalogue of spectroscopic binaries. That it was not arose from an unhappy accident in the observing program of Daniel M. Popper long before the discovery of X-ray binaries and the identification of Cygnus X-1 with that hot, massive star and its collapsed companion.

  18. Spectroscopic Studies of Solar Corona VI: Trend in Line-width Variation of Coronal Emission Lines with Height Independent of the Structure of Coronal Loops

    Indian Academy of Sciences (India)

    Jagdev Singh; Takashi Sakurai; Kiyoshi Ichimoto; S. Muneer

    2006-06-01

    We have obtained spectroscopic observations in coronal emission lines by choosing two lines simultaneously, one [Fe X] 6374 Å and the other [Fe XI] 7892 Å or [Fe XIII] 10747 Å or [Fe XIV] 5303 Å. We found that in 95 per cent of the coronal loops observed in 6374 Å, the FWHM of the emission line increases with height above the limb irrespective of the size, shape and orientation of the loop and that in case of 5303 Å line decreases with height in about 89 per cent of the coronal loops. The FWHM of 7892 Å and 10747 Å emission lines show intermediate behavior. The increase in the FWHM of 6374 Å line with height is the steepest among these four lines.We have also studied the intensity ratio and ratio of FWHM of these lines with respect to those of 6374 Å as a function height above the limb. We found that the intensity ratio of 7892 Å and 10747 Å lines with respect to 6374 Å line increases with height and that of 5303 Å to 6374 Å decreases with height above the limb. This implies that temperature in coronal loops will appear to increase with height in the intensity ratio plots of 7892 Å and 6374 Å; and 10747 Å and 6374 Å whereas it will appear to decrease with height in intensity ratio of 5303 Å to 6374 Å line versus height plot. These findings are up to a height of about 200 arcsec above the limb. The varying ratios with height indicate that relatively hotter and colder plasma in coronal loops interact with each other. Therefore, the observed increase in FWHM with height above the limb of coronal emission lines associated with plasma at about 1 MK may not be due to increase in non-thermal motions caused by coronal waves but due to interaction with the relatively hotter plasma. These findings also do not support the existing coronal loop models, which predict an increase in temperature of the loop with height above the limb.

  19. BAT AGN Spectroscopic Survey - IV: Near-Infrared Coronal Lines, Hidden Broad Lines, and Correlation with Hard X-ray Emission

    Science.gov (United States)

    Lamperti, Isabella; Koss, Michael; Trakhtenbrot, Benny; Schawinski, Kevin; Ricci, Claudio; Oh, Kyuseok; Landt, Hermine; Riffel, Rogério; Rodríguez-Ardila, Alberto; Gehrels, Neil; Harrison, Fiona; Masetti, Nicola; Mushotzky, Richard; Treister, Ezequiel; Ueda, Yoshihiro; Veilleux, Sylvain

    2017-01-01

    We provide a comprehensive census of the near-Infrared (NIR, 0.8-2.4 μm) spectroscopic properties of 102 nearby (z X-ray band (14-195 keV) from the Swift-Burst Alert Telescope (BAT) survey. With the launch of the James Webb Space Telescope this regime is of increasing importance for dusty and obscured AGN surveys. We measure black hole masses in 68% (69/102) of the sample using broad emission lines (34/102) and/or the velocity dispersion of the Ca II triplet or the CO band-heads (46/102). We find that emission line diagnostics in the NIR are ineffective at identifying bright, nearby AGN galaxies because ([Fe II] 1.257μm/Paβ and H2 2.12μm/Brγ) identify only 25% (25/102) as AGN with significant overlap with star forming galaxies and only 20% of Seyfert 2 have detected coronal lines (6/30). We measure the coronal line emission in Seyfert 2 to be weaker than in Seyfert 1 of the same bolometric luminosity suggesting obscuration by the nuclear torus. We find that the correlation between the hard X-ray and the [Fe II] coronal line luminosity is significantly better than with the [O III] λ5007 luminosity. Finally, we find 3/29 galaxies (10%) that are optically classified as Seyfert 2 show broad emission lines in the NIR. These AGN have the lowest levels of obscuration among the Seyfert 2s in our sample (log NH < 22.43 cm-2), and all show signs of galaxy-scale interactions or mergers suggesting that the optical broad emission lines are obscured by host galaxy dust.

  20. The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: Search for [CII] Line and Dust Emission in 6

    Science.gov (United States)

    Aravena, M.; Decarli, R.; Walter, F.; Bouwens, R.; Oesch, P. A.; Carilli, C. L.; Bauer, F. E.; Da Cunha, E.; Daddi, E.; Gónzalez-López, J.; Ivison, R. J.; Riechers, D. A.; Smail, I.; Swinbank, A. M.; Weiss, A.; Anguita, T.; Bacon, R.; Bell, E.; Bertoldi, F.; Cortes, P.; Cox, P.; Hodge, J.; Ibar, E.; Inami, H.; Infante, L.; Karim, A.; Magnelli, B.; Ota, K.; Popping, G.; van der Werf, P.; Wagg, J.; Fudamoto, Y.

    2016-12-01

    We present a search for [C ii] line and dust continuum emission from optical dropout galaxies at z > 6 using ASPECS, our Atacama Large Millimeter submillimeter Array Spectroscopic Survey in the Hubble Ultra-deep Field (UDF). Our observations, which cover the frequency range of 212-272 GHz, encompass approximately the range of 6 4.5σ, two of which correspond to blind detections with no optical counterparts. At this significance level, our statistical analysis shows that about 60% of our candidates are expected to be spurious. For one of our blindly selected [C ii] line candidates, we tentatively detect the CO(6-5) line in our parallel 3 mm line scan. None of the line candidates are individually detected in the 1.2 mm continuum. A stack of all [C ii] candidates results in a tentative detection with S 1.2 mm = 14 ± 5 μJy. This implies a dust-obscured star-formation rate (SFR) of (3 ± 1) M ⊙ yr-1. We find that the two highest-SFR objects have candidate [C ii] lines with luminosities that are consistent with the low-redshift L [C ii] versus SFR relation. The other candidates have significantly higher [C ii] luminosities than expected from their UV-based SFR. At the current sensitivity, it is unclear whether the majority of these sources are intrinsically bright [C ii] emitters, or spurious sources. If only one of our line candidates was real (a scenario greatly favored by our statistical analysis), we find a source density for [C ii] emitters at 6 universe.

  1. 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

  2. Spectroscopic investigations on glasses, glass-ceramics and ceramics developed for nuclear waste immobilization

    Science.gov (United States)

    Caurant, D.

    2014-05-01

    Highly radioactive nuclear waste must be immobilized in very durable matrices such as glasses, glass-ceramics and ceramics in order to avoid their dispersion in the biosphere during their radioactivity decay. In this paper, we present various examples of spectroscopic investigations (optical absorption, Raman, NMR, EPR) performed to study the local structure of different kinds of such matrices used or envisaged to immobilize different kinds of radioactive wastes. A particular attention has been paid on the incorporation and the structural role of rare earths—both as fission products and actinide surrogates—in silicate glasses and glass-ceramics. An example of structural study by EPR of a ceramic (hollandite) irradiated by electrons (to simulate the effect of the β-irradiation of radioactive cesium) is also presented.

  3. Spectroscopic investigation of asteroids belonging to the Themis and Beagle families

    Science.gov (United States)

    Fornasier, S.; Perna, D.; Barucci, M. A.; Merlin, F.; Dotto, E.

    2012-09-01

    24 Themis is the largest body of the Themis family. Within this big family a cluster of very young asteroids (age Beagle sub-family, has been identified. Recently water ice and organics were detected on 24 Themis indicating that the Themis family may be an important reservoir of ice. Moreover, the main belt comets 133P, 238P, and 176P may be related with the Themis family because of orbital proximities and spectral properties analogies. The aim of this work is to spectroscopically investigate some asteroids belonging to the Themis family and to the young Beagle sub-family in order to look for absorption bands related to water ice, hydrated silicates and organics.

  4. A spectroscopic analysis of a sample of narrow-line Seyfert 1 galaxies selected from the Sloan Digital Sky Survey

    CERN Document Server

    Cracco, V; Berton, M; Di Mille, F; Foschini, L; La Mura, G; Rafanelli, P

    2016-01-01

    We revisited the spectroscopic characteristics of narrow-line Seyfert 1 galaxies (NLS1s) by analysing a homogeneous sample of 296 NLS1s at redshift between 0.028 and 0.345, extracted from the Sloan Digital Sky Survey (SDSS-DR7) public archive. We confirm that NLS1s are mostly characterized by Balmer lines with Lorentzian profiles, lower black hole masses and higher Eddington ratios than classic broad-line Seyfert 1 (BLS1s), but they also appear to be active galactic nuclei (AGNs) contiguous with BLS1s and sharing with them common properties. Strong Fe II emission does not seem to be a distinctive property of NLS1s, as low values of Fe II/H$\\beta$ are equally observed in these AGNs. Our data indicate that Fe II and Ca II kinematics are consistent with the one of H$\\beta$. On the contrary, O I $\\lambda$8446 seems to be systematically narrower and it is likely emitted by gas of the broad-line region more distant from the ionizing source and showing different physical properties. Finally, almost all NLS1s of our ...

  5. Space Telescope and Optical Reverberation Mapping Project. V. Optical Spectroscopic Campaign and Emission-line Analysis for NGC 5548

    Science.gov (United States)

    Pei, L.; Fausnaugh, M. M.; Barth, A. J.; Peterson, B. M.; Bentz, M. C.; De Rosa, G.; Denney, K. D.; Goad, M. R.; Kochanek, C. S.; Korista, K. T.; Kriss, G. A.; Pogge, R. W.; Bennert, V. N.; Brotherton, M.; Clubb, K. I.; Dalla Bontà, E.; Filippenko, A. V.; Greene, J. E.; Grier, C. J.; Vestergaard, M.; Zheng, W.; Adams, Scott M.; Beatty, Thomas G.; Bigley, A.; Brown, Jacob E.; Brown, Jonathan S.; Canalizo, G.; Comerford, J. M.; Coker, Carl T.; Corsini, E. M.; Croft, S.; Croxall, K. V.; Deason, A. J.; Eracleous, Michael; Fox, O. D.; Gates, E. L.; Henderson, C. B.; Holmbeck, E.; Holoien, T. W.-S.; Jensen, J. J.; Johnson, C. A.; Kelly, P. L.; Kim, S.; King, A.; Lau, M. W.; Li, Miao; Lochhaas, Cassandra; Ma, Zhiyuan; Manne-Nicholas, E. R.; Mauerhan, J. C.; Malkan, M. A.; McGurk, R.; Morelli, L.; Mosquera, Ana; Mudd, Dale; Muller Sanchez, F.; Nguyen, M. L.; Ochner, P.; Ou-Yang, B.; Pancoast, A.; Penny, Matthew T.; Pizzella, A.; Poleski, Radosław; Runnoe, Jessie; Scott, B.; Schimoia, Jaderson S.; Shappee, B. J.; Shivvers, I.; Simonian, Gregory V.; Siviero, A.; Somers, Garrett; Stevens, Daniel J.; Strauss, M. A.; Tayar, Jamie; Tejos, N.; Treu, T.; Van Saders, J.; Vican, L.; Villanueva, S., Jr.; Yuk, H.; Zakamska, N. L.; Zhu, W.; Anderson, M. D.; Arévalo, P.; Bazhaw, C.; Bisogni, S.; Borman, G. A.; Bottorff, M. C.; Brandt, W. N.; Breeveld, A. A.; Cackett, E. M.; Carini, M. T.; Crenshaw, D. M.; De Lorenzo-Cáceres, A.; Dietrich, M.; Edelson, R.; Efimova, N. V.; Ely, J.; Evans, P. A.; Ferland, G. J.; Flatland, K.; Gehrels, N.; Geier, S.; Gelbord, J. M.; Grupe, D.; Gupta, A.; Hall, P. B.; Hicks, S.; Horenstein, D.; Horne, Keith; Hutchison, T.; Im, M.; Joner, M. D.; Jones, J.; Kaastra, J.; Kaspi, S.; Kelly, B. C.; Kennea, J. A.; Kim, M.; Kim, S. C.; Klimanov, S. A.; Lee, J. C.; Leonard, D. C.; Lira, P.; MacInnis, F.; Mathur, S.; McHardy, I. M.; Montouri, C.; Musso, R.; Nazarov, S. V.; Netzer, H.; Norris, R. P.; Nousek, J. A.; Okhmat, D. N.; Papadakis, I.; Parks, J. R.; Pott, J.-U.; Rafter, S. E.; Rix, H.-W.; Saylor, D. A.; Schnülle, K.; Sergeev, S. G.; Siegel, M.; Skielboe, A.; Spencer, M.; Starkey, D.; Sung, H.-I.; Teems, K. G.; Turner, C. S.; Uttley, P.; Villforth, C.; Weiss, Y.; Woo, J.-H.; Yan, H.; Young, S.; Zu, Y.

    2017-03-01

    We present the results of an optical spectroscopic monitoring program targeting NGC 5548 as part of a larger multiwavelength reverberation mapping campaign. The campaign spanned 6 months and achieved an almost daily cadence with observations from five ground-based telescopes. The Hβ and He ii λ4686 broad emission-line light curves lag that of the 5100 Å optical continuum by {4.17}-0.36+0.36 {days} and {0.79}-0.34+0.35 {days}, respectively. The Hβ lag relative to the 1158 Å ultraviolet continuum light curve measured by the Hubble Space Telescope is ∼50% longer than that measured against the optical continuum, and the lag difference is consistent with the observed lag between the optical and ultraviolet continua. This suggests that the characteristic radius of the broad-line region is ∼50% larger than the value inferred from optical data alone. We also measured velocity-resolved emission-line lags for Hβ and found a complex velocity-lag structure with shorter lags in the line wings, indicative of a broad-line region dominated by Keplerian motion. The responses of both the Hβ and He ii emission lines to the driving continuum changed significantly halfway through the campaign, a phenomenon also observed for C iv, Lyα, He ii(+O iii]), and Si iv(+O iv]) during the same monitoring period. Finally, given the optical luminosity of NGC 5548 during our campaign, the measured Hβ lag is a factor of five shorter than the expected value implied by the R BLR–L AGN relation based on the past behavior of NGC 5548.

  6. New precision orbits of bright double-lined spectroscopic binaries. IX. HD 54371, HR 2692, and 16 ursa majoris

    Energy Technology Data Exchange (ETDEWEB)

    Fekel, Francis C.; Williamson, Michael H.; Muterspaugh, Matthew W. [Center of Excellence in Information Systems, Tennessee State University, 3500 John A. Merritt Boulevard, Box 9501, Nashville, TN 37209 (United States); Pourbaix, Dimitri [FNRS Institut d’Astronomie et d’Astrophysique, Université Libre de Bruxelles, CP 226, B-1050 Bruxelles (Belgium); Willmarth, Daryl [Kitt Peak National Obsevatory, P.O. Box 26732, Tucson, AZ 85726-6732 (United States); Tomkin, Jocelyn, E-mail: fekel@evans.tsuniv.edu, E-mail: michael.h.williamson@gmail.com, E-mail: matthew1@coe.tsuniv.edu, E-mail: pourbaix@astro.ulb.ac.be, E-mail: dwillmarth@noao.edu [Astronomy Department and McDonald Observatory, University of Texas, Austin, TX 78712 (United States)

    2015-02-01

    With extensive sets of new radial velocities we have determined orbital elements for three previously known spectroscopic binaries, HD 54371, HR 2692, and 16 UMa. All three systems have had the lines of their secondaries detected for the first time. The orbital periods range from 16.24 to 113.23 days, and the three binaries have modestly or moderately eccentric orbits. The secondary to primary mass ratios range from 0.50 to 0.64. The orbital dimensions (a{sub 1} sin i and a{sub 2} sin i) and minimum masses (m{sub 1} sin{sup 3} i and m{sub 2} sin{sup 3} i) of the binary components all have accuracies of ⩽1%. With our spectroscopic results and the Hipparcos data, we also have determined astrometric orbits for two of the three systems, HR 2692 and 16 UMa. The primaries of HD 54371 and 16 UMa are solar-type stars, and their secondaries are likely K or M dwarfs. The primary of HR 2692 is a late-type subgiant and its secondary is a G or K dwarf. The primaries of both HR 2692 and 16 UMa may be pseudosynchronously rotating, while that of HD 54371 is rotating faster than its pseudosynchronous velocity.

  7. New Precision Orbits of Bright Double-Lined Spectroscopic Binaries. I: RR Lyncis, 12 Bootis, and HR 6169

    CERN Document Server

    Tomkin, J; Fekel, Francis C.; Tomkin, Jocelyn

    2006-01-01

    Radial velocities from the 2.1 m telescope at McDonald Observatory supplemented with radial velocities from the coude' feed telescope at KPNO provide new precise orbits for the double-lined spectroscopic binaries RR Lyn (A3/A8/A6), 12 Boo (F8IV), and HR 6169 (A2V). We derive orbital dimensions and minimum masses with accuracies of 0.06 to 0.9 %. The three systems, which have V magnitudes of 5.54, 4.83, and 6.42, respectively, are all sufficiently bright that they are easily within the grasp of modern optical interferometers and so afford the prospect, when our spectroscopic observations are complemented by interferometric observations, of fully-determined orbits, precise masses, and distances. In the case of RR Lyn, which is also a detached eclipsing binary with a well-determined orbital inclination, we are able to determine the semimajor axis of the relative orbit, a = 29.32 +/- 0.04 Rsun, primary and secondary radii of 2.57 +/- 0.02 Rsun and 1.59 +/- 0.03 Rsun, respectively; and primary and secondary masses...

  8. Investigating the spectroscopic, magnetic and circumstellar variability of the O9 subgiant star HD 57682

    CERN Document Server

    Grunhut, J H; Sundqvist, J O; ud-Doula, A; Neiner, C; Ignace, R; Marcolino, W L F; Rivinius, Th; Fullerton, A; Kaper, L; Mauclaire, B; Buil, C; Garrel, T; Ribeiro, J; Ubaud, S

    2012-01-01

    The O9IV star HD 57682, discovered to be magnetic within the context of the MiMeS survey in 2009, is one of only eight convincingly detected magnetic O-type stars. Among this select group, it stands out due to its sharp-lined photospheric spectrum. Since its discovery, the MiMeS Collaboration has continued to obtain spectroscopic and magnetic observations in order to refine our knowledge of its magnetic field strength and geometry, rotational period, and spectral properties and variability. In this paper we report new ESPaDOnS spectropolarimetric observations of HD 57682, which are combined with previously published ESPaDOnS data and archival H{\\alpha} spectroscopy. This dataset is used to determine the rotational period (63.5708 \\pm 0.0057 d), refine the longitudinal magnetic field variation and magnetic geometry (dipole surface field strength of 880\\pm50 G and magnetic obliquity of 79\\pm4\\circ as measured from the magnetic longitudinal field variations, assuming an inclination of 60\\circ), and examine the p...

  9. Accurate molecular structure and spectroscopic properties for nucleobases: A combined computational - microwave investigation of 2-thiouracil as a case study

    Science.gov (United States)

    Puzzarini, Cristina; Biczysko, Malgorzata; Barone, Vincenzo; Peña, Isabel; Cabezas, Carlos; Alonso, José L.

    2015-01-01

    The computational composite scheme purposely set up for accurately describing the electronic structure and spectroscopic properties of small biomolecules has been applied to the first study of the rotational spectrum of 2-thiouracil. The experimental investigation was made possible thanks to the combination of the laser ablation technique with Fourier Transform Microwave spectrometers. The joint experimental – computational study allowed us to determine accurate molecular structure and spectroscopic properties for the title molecule, but more important, it demonstrates a reliable approach for the accurate investigation of isolated small biomolecules. PMID:24002739

  10. Spectroscopic investigation of the interactions of carbofuran and amitrol herbicides with human serum albumin

    Energy Technology Data Exchange (ETDEWEB)

    Tunç, Sibel, E-mail: stunc@akdeniz.edu.tr; Duman, Osman, E-mail: osmanduman@akdeniz.edu.tr; Soylu, İnanç; Kancı Bozoğlan, Bahar

    2014-07-01

    In this study, various spectroscopic techniques including UV absorption, fluorescence and synchronous fluorescence spectroscopy were used to examine the interactions of carbofuran (CF) and amitrol (AMT) herbicides with human serum albumin (HSA). The results of spectroscopic experiments illustrated that CF was bound by HSA, on the other hand there was no interaction between HSA and AMT molecules. In HSA–CF system, static quenching mechanism was responsible for the fluorescence quenching of HSA. The Stern–Volmer constant and binding constant decreased with increasing temperature. This means that an increase in temperature reduces the stability of HSA–CF complex. In HSA–CF system, the number of binding site on protein was found to be one. From the thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS) were calculated as −22.30 kJ mol{sup −1} and −10.70 J mol{sup −1} K{sup −1}, respectively, which indicated that the interaction forces between HSA and CF molecules were mainly hydrogen bonding and van der Waals forces. The conformational change in the protein structure was investigated by synchronous fluorescence spectroscopy. According to the results of synchronous fluorescence analysis, there was a change in the protein structure owing to the interaction of CF with HSA. - Highlights: • UV absorption, fluorescence and synchronous fluorescence measurements confirm the formation of HSA–CF complex. • The formation of HSA–CF complex involves both hydrogen bonding and van der Waals forces. • There is no interaction between HSA and AMT molecules. • Binding constants, numbers of binding sites and thermodynamic parameters have been calculated. • The binding of CF to HSA changes the conformational structure of protein.

  11. Investigation of neohesperidin dihydrochalcone binding to human serum albumin by spectroscopic methods

    Energy Technology Data Exchange (ETDEWEB)

    Bozoğlan, Bahar Kancı; Tunç, Sibel, E-mail: stunc@akdeniz.edu.tr; Duman, Osman, E-mail: osmanduman@akdeniz.edu.tr

    2014-11-15

    In this study, the interaction of human serum albumin (HSA) with neohesperidin dihydrochalcone (NHD) was investigated by UV, fluorescence, synchronous fluorescence and circular dichroism spectroscopic methods. Experimental results confirmed the complex formation between HSA and NHD molecules under physiological conditions. NHD quenched the intrinsic fluorescence spectrum of HSA by static quenching mechanism. The binding constant of this system was calculated as 2.79×10{sup 4} M{sup −1} at 298.15 K. The stability of HSA–NHD complex illustrated a decrease with increasing temperature. The number of binding sites was found to be 1. Thermodynamic parameter values were calculated by using van’t Hoff equation. According to sign and magnitude of thermodynamic parameters (ΔH=−29.22 kJ mol{sup −1} and ΔS=−12.91 J mol{sup −1} K{sup −1}), hydrogen bonding and van der Waals forces were found as the effective interaction forces between HSA and NHD molecules. Synchronous fluorescence and circular dichroism spectroscopic methods proved the alteration of secondary structure of HSA in the presence of NHD. Site marker competitive experiments indicated that the binding of NHD to HSA took place in subdomain IIA region of protein. - Highlights: • Static quenching mechanism is effective in the interaction of HSA with NHD. • Hydrogen bonding and van der Waals forces play an important role in the binding process. • NHD causes a slight change in the conformational structure of HSA. • The binding site of NHD takes place in subdomain IIA region of HSA.

  12. Spatially selective T2 and T2 ∗ measurement with line-scan echo-planar spectroscopic imaging

    Science.gov (United States)

    Chen, Nan-kuei; Oshio, Koichi; Panych, Lawrence P.; Rybicki, Frank J.; Mulkern, Robert V.

    2004-11-01

    Line-scan echo planar spectroscopic imaging (LSEPSI) is applied to quickly measure the T2 and T2 ∗ relaxation time constants in pre-selected 2D or 3D regions. Results from brain imaging studies at 3 T suggest that the proposed method may prove valuable for both basic research (e.g., quantifying the changes of T2/T2 ∗ values in functional MRI with blood oxygenation level-dependent contrast) and clinical studies (e.g., measuring the T2' shortening due to iron deposition). The proposed spatially selective T2 and T2 ∗ mapping technique is especially well suited for studies, where T2/T2 ∗ quantification needs to be performed dynamically in a pre-selected 2D or 3D region.

  13. The Wasilewski sample of emission-line galaxies - Follow-up CCD imaging and spectroscopic and IRAS observations

    Science.gov (United States)

    Bothun, Gregory D.; Schmitz, Mark; Halpern, Jules P.; Lonsdale, Carol J.; Impey, Chris

    1989-06-01

    The results of an extensive imaging and spectroscopic follow-up of the objective prism-selected emission line galaxy (ELG) sample of Wasilewski (1982) are presented. Fluxes at 12, 25, 60, and 100 microns were also obtained from the coadded IRAS survey data. ELGs found by objective prism surveys are found to be generally small and underluminous galaxies which usually have higher than average optical surface brightness. The Seyfert detection rate in objective prism surveys is roughly 10 percent and the ratio of the space densities of Seyfert 2 to Seyfert 1 galaxies is significantly larger than unity. Most of the galaxies selected by objective prism surveys are star-forming, late-type spirals which often show disturbed morphology. About 25 percent of the galaxies detected by the surveys are faint, high-excitation metal-poor compact H II regions.

  14. Investigation of radiosensitivity gene signatures in cancer cell lines.

    Directory of Open Access Journals (Sweden)

    John S Hall

    Full Text Available Intrinsic radiosensitivity is an important factor underlying radiotherapy response, but there is no method for its routine assessment in human tumours. Gene signatures are currently being derived and some were previously generated by expression profiling the NCI-60 cell line panel. It was hypothesised that focusing on more homogeneous tumour types would be a better approach. Two cell line cohorts were used derived from cervix [n = 16] and head and neck [n = 11] cancers. Radiosensitivity was measured as surviving fraction following irradiation with 2 Gy (SF2 by clonogenic assay. Differential gene expression between radiosensitive and radioresistant cell lines (SF2 median was investigated using Affymetrix GeneChip Exon 1.0ST (cervix or U133A Plus2 (head and neck arrays. There were differences within cell line cohorts relating to tissue of origin reflected by expression of the stratified epithelial marker p63. Of 138 genes identified as being associated with SF2, only 2 (1.4% were congruent between the cervix and head and neck carcinoma cell lines (MGST1 and TFPI, and these did not partition the published NCI-60 cell lines based on SF2. There was variable success in applying three published radiosensitivity signatures to our cohorts. One gene signature, originally trained on the NCI-60 cell lines, did partially separate sensitive and resistant cell lines in all three cell line datasets. The findings do not confirm our hypothesis but suggest that a common transcriptional signature can reflect the radiosensitivity of tumours of heterogeneous origins.

  15. Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line

    Science.gov (United States)

    Cheng, X.; Ding, M. D.

    2016-05-01

    In this Letter, we present Interface Region Imaging Spectrograph Fe xxi 1354.08 Å forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of ≥1000 km s-1 and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The extreme-ultraviolet images at the 131 and 94 Å passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe xxi 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe xxi forbidden line requires a critical temperature (˜11.5 MK) and density. Moreover, the line shows a non-thermal broadening and a blueshift in the early phase. It suggests that magnetic reconnection at that time has initiated; it not only heats the MFR and, at the same time, produces a non-thermal broadening of the Fe xxi line but also produces the poloidal flux, leading to the ascension of the MFRs.

  16. Process Analytical Technology and On-Line Spectroscopic Measurements of Chemical Meat Quality

    DEFF Research Database (Denmark)

    Sørensen, Klavs Martin

    This thesis deals with process analytical technology and how it can be implemented in the meat industry through on-line grading of chemical meat quality. The focus will be on two applications, namely the rapid quality control of fat quality and the development of a method for on-line detection of...... quality, but also with environmental issues such as energy and water use and animal welfare. Future research into the technologies will ultimately allow broad on-line screening of biomarkers, leading to on-line metabolomics......This thesis deals with process analytical technology and how it can be implemented in the meat industry through on-line grading of chemical meat quality. The focus will be on two applications, namely the rapid quality control of fat quality and the development of a method for on-line detection...... of boar taint. The chemical makeup of fat has a large effect on meat cut quality. Fat quality has traditionally been determined by methylation of a tissue sample followed by chromatography on a GC-MS system, elucidating the composition of the individual fatty acids. As this procedure typically takes far...

  17. Investigation of a transiting planet candidate in Trumpler 37: an astrophysical false positive eclipsing spectroscopic binary star

    CERN Document Server

    Errmann, R; Schmidt, T O B; Seeliger, M; Howard, A W; Maciejewski, G; Neuhäuser, R; Meibom, S; Kellerer, A; Dimitrov, D P; Dincel, B; Marka, C; Mugrauer, M; Ginski, Ch; Adam, Ch; Raetz, St; Schmidt, J G; Hohle, M M; Berndt, A; Kitze, M; Trepl, L; Moualla, M; Eisenbeiß, T; Fiedler, S; Dathe, A; Graefe, Ch; Pawellek, N; Schreyer, K; Kjurkchieva, D P; Radeva, V S; Yotov, V; Chen, W P; Hu, S C -L; Wu, Z -Y; Zhou, X; Pribulla, T; Budaj, J; Vaňko, M; Kundra, E; Hambálek, Ľ; Krushevska, V; Bukowiecki, Ł; Nowak, G; Marschall, L; Terada, H; Tomono, D; Fernandez, M; Sota, A; Takahashi, H; Oasa, Y; Briceño, C; Chini, R; Broeg, C H

    2014-01-01

    We report our investigation of the first transiting planet candidate from the YETI project in the young (~4 Myr old) open cluster Trumpler 37. The transit-like signal detected in the lightcurve of the F8V star 2M21385603+5711345 repeats every 1.364894+/-0.000015 days, and has a depth of 54.5+/-0.8 mmag in R. Membership to the cluster is supported by its mean radial velocity and location in the color-magnitude diagram, while the Li diagnostic and proper motion are inconclusive in this regard. Follow-up photometric monitoring and adaptive optics imaging allow us to rule out many possible blend scenarios, but our radial-velocity measurements show it to be an eclipsing single-lined spectroscopic binary with a late-type (mid-M) stellar companion, rather than one of planetary nature. The estimated mass of the companion is 0.15-0.44 solar masses. The search for planets around very young stars such as those targeted by the YETI survey remains of critical importance to understand the early stages of planet formation a...

  18. Neutron-diffraction investigations of flux-lines in superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Forgan, E.M. [Birmingham Univ. (United Kingdom); Lee, S.L. [Saint Andrews Univ. (United Kingdom); McKPaul, D. [Warwick Univ., Coventry (United Kingdom); Mook, H.A. [Oak Ridge National Lab., TN (United States); Cubitt, R. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    SANS has proved an extremely useful tool for investigating flux-line structures within the bulk of superconductors. With high-T{sub c} materials, the scattered intensities are weak, but careful measurements are giving important new information about flux lattices, flux pinning and flux-lattice melting. (author). 10 refs.

  19. FT-infrared spectroscopic studies of lymphoma, lymphoid, and myeloid leukemia cell lines

    Science.gov (United States)

    Babrah, Jaspreet; McCarthy, Keith P.; Lush, Richard; Rye, Adam D.; Bessant, Conrad; Stone, Nicholas

    2007-07-01

    This paper presents a novel method to characterise spectral differences that distinguish leukaemia and lymphoma cell lines. This is based on objective spectral measurements of major cellular biochemical constituents and multivariate spectral processing. Fourier transform infrared (FT-IR) maps of the lymphoma, lymphoid and myeloid leukaemia cell samples were obtained using a Perkin-Elmer Spotlight 300 FT-IR imaging spectrometer. Multivariate statistical techniques incorporating principal component analysis (PCA) and linear discriminant analysis (LDA) were used to construct a mathematical model. This model was validated for reproducibility. Multivariate statistical analysis of FTIR spectra collected for each cell sample permit a combination of unsupervised and supervised methods of distinguishing cell line types. This resulted in the clustering of cell line populations, indicating distinct bio-molecular differences. Major spectral differences were observed in the 4000 to 800 cm -1 spectral region. Bands in the averaged spectra for the cell line were assigned to the major biochemical constituents including; proteins, fatty acids, carbohydrates and nucleic acids. The combination of FT-IR spectroscopy and multivariate statistical analysis provides an important insight into the fundamental spectral differences between the cell lines, which differ according to the cellular biochemical composition. These spectral differences can serve as potential biomarkers for the differentiation of leukaemia and lymphoma cells. Consequently these differences could be used as the basis for developing a spectral method for the detection and identification of haematological malignancies.

  20. Process Analytical Technology and On-Line Spectroscopic Measurements of Chemical Meat Quality

    DEFF Research Database (Denmark)

    Sørensen, Klavs Martin

    This thesis deals with process analytical technology and how it can be implemented in the meat industry through on-line grading of chemical meat quality. The focus will be on two applications, namely the rapid quality control of fat quality and the development of a method for on-line detection...... of boar taint. The chemical makeup of fat has a large effect on meat cut quality. Fat quality has traditionally been determined by methylation of a tissue sample followed by chromatography on a GC-MS system, elucidating the composition of the individual fatty acids. As this procedure typically takes far...... on surgical castration will be in effect starting 2018. With the ban, the risk of meat products with the malodorous taint reaching the consumer is highly increased, and thus, detection of boar taint is a necessity. No current on-line detection system is available; the only alternative is chemical extraction...

  1. Candidate Water Vapor Lines to Locate the H2O Snowline through High-dispersion Spectroscopic Observations. I. The Case of a T Tauri Star

    Science.gov (United States)

    Notsu, Shota; Nomura, Hideko; Ishimoto, Daiki; Walsh, Catherine; Honda, Mitsuhiko; Hirota, Tomoya; Millar, T. J.

    2016-08-01

    Inside the H2O snowline of protoplanetary disks, water evaporates from the dust-grain surface into the gas phase, whereas it is frozen out onto the dust in the cold region beyond the snowline. H2O ice enhances the solid material in the cold outer part of a disk, which promotes the formation of gas-giant planet cores. We can regard the H2O snowline as the surface that divides the regions between rocky and gaseous giant planet formation. Thus observationally measuring the location of the H2O snowline is crucial for understanding the planetesimal and planet formation processes, and the origin of water on Earth. In this paper, we find candidate water lines to locate the H2O snowline through future high-dispersion spectroscopic observations. First, we calculate the chemical composition of the disk and investigate the abundance distributions of H2O gas and ice, and the position of the H2O snowline. We confirm that the abundance of H2O gas is high not only in the hot midplane region inside the H2O snowline but also in the hot surface layer of the outer disk. Second, we calculate the H2O line profiles and identify those H2O lines that are promising for locating the H2O snowline: the identified lines are those that have small Einstein A coefficients and high upper state energies. The wavelengths of the candidate H2O lines range from mid-infrared to sub-millimeter, and they overlap with the regions accessible to the Atacama Large Millimeter/sub-millimeter Array and future mid-infrared high-dispersion spectrographs (e.g., TMT/MICHI, SPICA).

  2. 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.

  3. 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.

  4. Recommended isolated-line profile for representing high-resolution spectroscopic transitions (IUPAC Technical Report)

    CERN Document Server

    Tennyson, Jonathan; Campargue, Alain; Csaszar, Attila G; Daumont, Ludovic; Gamache, Robert R; Hodges, Joseph T; Lisak, Daniel; Naumenko, Olga V; Rothman, Laurence S; Tran, Ha; Zobov, Nikolai F; Buldyreva, Jeanna; Boone, Chris D; De Vizia, Maria Domenica; Gianfrani, Livio; Hartmann, Jean-Michel; McPheat, Robert; Murray, Jonathan; Ngo, Ngoc Hoa; Polyansky, Oleg L; Weidmann, Damien

    2014-01-01

    The report of an IUPAC Task Group, formed in 2011 on "Intensities and line shapes in high-resolution spectra of water isotopologues from experiment and theory" (Project No. 2011-022-2-100), on line profiles of isolated high-resolution rotational-vibrational transitions perturbed by neutral gas-phase molecules is presented. The well-documented inadequacies of the Voigt profile (VP), used almost universally by databases and radiative-transfer codes, to represent pressure effects and Doppler broadening in isolated vibrational-rotational and pure rotational transitions of the water molecule have resulted in the development of a variety of alternative line-profile models. These models capture more of the physics of the influence of pressure on line shapes but, in general, at the price of greater complexity. The Task Group recommends that the partially Correlated quadratic-Speed-Dependent Hard-Collision profile should be adopted as the appropriate model for high-resolution spectroscopy. For simplicity this should b...

  5. Spectroscopic Study of `CO’ and its Isotopic mm/Submillimeter Lines from Dark Cloud Lynds 183

    Indian Academy of Sciences (India)

    R. S. Thampi; L. Pagani

    2010-03-01

    We have made spectral line analysis of CO and its isotopic lines from dark cloud Lynds 183 (L183). Our dataset incorporates 12CO(1––0), 13CO(1––0) and 13CO(2––1) lines using NRAO-12m and 12CO(3––2), 13CO(3––2) lines using CSO-10m telescopes, respectively. Observations suggest steep north-south (direction with respect to the offset position (0, 0)) temperature gradient in the cloud. These are likely to be caused by non-uniform, Inter Stellar Radiation Field (ISRF) illumination due to the shadow of nearby L134 cloud complex. As the emission of radiation depends on local properties like density and kinetic temperature, the present study attempts to deduce the irradiation contrast (and the resulting temperature difference) using 1D Monte Carlo radiative transfer code RATRAN. The model results accord with the observed data and shows a temperature difference of ∼ 7 K mainly within the cloud envelope. This results in a non-uniform intensity distribution of both CO and its species.

  6. Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line

    CERN Document Server

    Cheng, X

    2016-01-01

    In this Letter, we present Interface Region Imaging Spectrograph Fe XXI 1354.08 A forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of $\\ge$1000 km s$^{-1}$ and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The EUV images at the 131 A and 94 A passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe XXI 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe XXI forbidden line requires a critical temperature ($\\sim$11.5 MK) and dens...

  7. In situ spectroscopic investigation of the cobalt-catalyzed oxidation of lignin model compounds in ionic liquids

    NARCIS (Netherlands)

    Zakzeski, J.; Bruijnincx, P.C.A.; Weckhuysen, B.M.

    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 com

  8. 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.

    2017-07-01

    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.

  9. Experimental Investigation of two-phase nitrogen Cryo transfer line

    Science.gov (United States)

    Singh, G. K.; Nimavat, H.; Panchal, R.; Garg, A.; Srikanth, GLN; Patel, K.; Shah, P.; Tanna, V. L.; Pradhan, S.

    2017-02-01

    A 6-m long liquid nitrogen based cryo transfer line has been designed, developed and tested at IPR. The test objectives include the thermo-hydraulic characteristics of Cryo transfer line under single phase as well as two phase flow conditions. It is always easy in experimentation to investigate the thermo-hydraulic parameters in case of single phase flow of cryogen but it is real challenge when one deals with the two phase flow of cryogen due to availibity of mass flow measurements (direct) under two phase flow conditions. Established models have been reported in the literature where one of the well-known model of Lockhart-Martenelli relationship has been used to determine the value of quality at the outlet of Cryo transfer line. Under homogenous flow conditions, by taking the ratio of the single-phase pressure drop and the two-phase pressure drop, we estimated the quality at the outlet. Based on these equations, vapor quality at the outlet of the transfer line was predicted at different heat loads. Experimental rresults shown that from inlet to outlet, there is a considerable increment in the pressure drop and vapour quality of the outlet depending upon heat load and mass flow rate of nitrogen flowing through the line.

  10. Early Results from the Galactic O-Star Spectroscopic Survey: C III Emission Lines in Of Spectra

    CERN Document Server

    Walborn, Nolan R; Apellaniz, Jesus Maiz; Alfaro, Emilio J; Morrell, Nidia I; Barba, Rodolfo H; Arias, Julia I; Gamen, Roberto C

    2010-01-01

    On the basis of an extensive new spectroscopic survey of Galactic O stars, we introduce the Ofc category, which consists of normal spectra with C III \\lambda\\lambda4647-4650-4652 emission lines of comparable intensity to those of the Of defining lines N III \\lambda\\lambda4634-4640-4642. The former feature is strongly peaked to spectral type O5, at all luminosity classes, but preferentially in some associations or clusters and not others. The relationships of this phenomenon to the selective C III \\lambda5696 emission throughout the normal Of domain, and to the peculiar, variable Of?p category, for which strong C III \\lambda\\lambda4647-4650-4652 emission is a defining characteristic, are discussed. Magnetic fields have recently been detected on two members of the latter category. We also present two new extreme Of?p stars, NGC 1624-2 and CPD -28^{\\circ}2561, bringing the number known in the Galaxy to five. Modeling of the behavior of these spectral features can be expected to better define the physical paramet...

  11. Development and Experimental Testing of an Optical Micro-Spectroscopic Technique Incorporating True Line-Scan Excitation

    Directory of Open Access Journals (Sweden)

    Gabriel Biener

    2013-12-01

    Full Text Available Multiphoton micro-spectroscopy, employing diffraction optics and electron-multiplying CCD (EMCCD cameras, is a suitable method for determining protein complex stoichiometry, quaternary structure, and spatial distribution in living cells using Förster resonance energy transfer (FRET imaging. The method provides highly resolved spectra of molecules or molecular complexes at each image pixel, and it does so on a timescale shorter than that of molecular diffusion, which scrambles the spectral information. Acquisition of an entire spectrally resolved image, however, is slower than that of broad-bandwidth microscopes because it takes longer times to collect the same number of photons at each emission wavelength as in a broad bandwidth. Here, we demonstrate an optical micro-spectroscopic scheme that employs a laser beam shaped into a line to excite in parallel multiple sample voxels. The method presents dramatically increased sensitivity and/or acquisition speed and, at the same time, has excellent spatial and spectral resolution, similar to point-scan configurations. When applied to FRET imaging using an oligomeric FRET construct expressed in living cells and consisting of a FRET acceptor linked to three donors, the technique based on line-shaped excitation provides higher accuracy compared to the point-scan approach, and it reduces artifacts caused by photobleaching and other undesired photophysical effects.

  12. A slitless spectroscopic survey for Halpha emission-line objects in SMC clusters

    CERN Document Server

    Martayan, Christophe; Fabregat, Juan

    2009-01-01

    This paper checks on the roles of metallicity and evolutionary age in the appearance of the so-called Be phenomenon. Slitless CCD spectra were obtained covering the bulk of the Small Magellanic Cloud. For Halpha line emission twice as strong as the ambient continuum, the survey is complete to spectral type B2/B3 on the main sequence. About 8120 spectra of 4437 stars were searched for emission lines in 84 open clusters. 370 emission-line stars were found, among them at least 231 near the main sequence. For 176 of them, photometry could be found in the OGLE database. For comparison with a higher-metallicity environment, the Galactic sample of the photometric Halpha survey by McSwain & Gies (2005) was used. Among early spectral sub-types, Be stars are more frequent by a factor 3-5 in the SMC than in the Galaxy. The distribution with spectral type is similar in both galaxies, i.e. not strongly dependent on metallicity. The fraction of Be stars does not seem to vary with local star density. The Be phenomenon m...

  13. Investigation of water aggressiveness towards concrete shaft lining

    Energy Technology Data Exchange (ETDEWEB)

    Majzner-Rulka, H.; Durczynski, S.

    1989-09-01

    Considers the corrosive action exerted by water on concrete shaft linings. Several kinds of water aggressiveness are distinguished: sulfate, acidic, carbonate, magnesian, leachate and of the ammonium type. Laboratory and in situ investigations into water aggressiveness towards shaft lining are described and results are presented. Related Polish standards are discussed. Presence of a new kind of water was established in which Mg{sup 2+} ion concentration reaches 4,500 mg/dm{sup 3} and SO{sub 4}{sup 2-} ion concentration exceeds 3,000 mg/dm{sup 3}. Damage to concrete shaft lining caused by aggressive water was found in shafts of several mines in the Upper Silesia coal basin. Investigations into the effect of high Mg{sup 2+} and SO{sub 4}{sup 2-} ion concentration in water on concrete shaft lining have been conducted at the Research and Development Department of the Mine Work Enterprise Budokop in Myslowice since 1984. Redrafting of related standards is recommended. 5 refs.

  14. Multi-spectroscopic investigation of the binding interaction of fosfomycin with bovine serum albumin☆

    Institute of Scientific and Technical Information of China (English)

    Manjunath D. Meti; Sharanappa T. Nandibewoor; Shrinivas D. Joshi; Uttam A. More; Shivamurti A. Chimatadar

    2015-01-01

    The interaction between fosfomycin (FOS) and bovine serum albumin (BSA) has been investigated effectively by multi-spectroscopic techniques under physiological pH 7.4. FOS quenched the intrinsic fluorescence of BSA via static quenching. The number of binding sites n and observed binding constant KA were measured by the fluorescence quenching method. The thermodynamic parameters △G0, △H0 and △S0 were calculated at different temperatures according to the van't Hoff equation. The site of binding of FOS in the protein was proposed to be Sudlow's site I based on displacement experiments using site markers viz. warfarin, ibuprofen and digitoxin. The distance r between the donor (BSA) and acceptor (FOS) molecules was obtained according to the F?rster theory. The effect of FOS on the conformation of BSA was analyzed using synchronous fluorescence spectra (SFS), circular dichroism (CD) and 3D fluorescence spectra. A molecular modeling study further confirmed the binding mode obtained by the experimental studies.

  15. 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.

  16. Corrosion investigation of fire-gilded bronze involving high surface resolution spectroscopic imaging

    Science.gov (United States)

    Masi, G.; Chiavari, C.; Avila, J.; Esvan, J.; Raffo, S.; Bignozzi, M. C.; Asensio, M. C.; Robbiola, L.; Martini, C.

    2016-03-01

    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 (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 chemical imaging using HR-SRPES to study artworks have been investigated on representative replicas.

  17. A spectroscopic investigation into the reaction of sodium tetrathionate with cysteine

    Science.gov (United States)

    Church, J. S.; Evans, D. J.

    2008-01-01

    A spectroscopic investigation into the reaction of sodium tetrathionate with cysteine at pH 5 both at the boil and at room temperature has been carried out. The Raman and infrared spectra of the model compounds cysteine, cysteine- S-sulfonate, cysteine- S-thiosulfonate, sodium thiosulfate and sodium sulfite were also obtained and vibrations involving the sulfur atoms were analyzed in detail. These results were utilized in the interpretation of the spectra obtained from tetrathionate-cysteine reaction mixtures. The reaction supernatants were analyzed by high performance thin layer chromatography while the precipitates were analyzed gravimetrically. It was found that during the reaction, the thiol groups of cysteine are oxidised to give predominantly cysteine- S-sulfonate. Cystine was also detected but was determined gravimetrically to be a minor reaction product. No significant amounts of cysteine- S-thiosulfonate were detected. The reaction is accompanied by the formation of elemental sulfur and a small amount of sulfite. Major reaction pathways are put forth that are consistent with the experimental data.

  18. Investigation of laser-tissue interaction in medicine by means of laser spectroscopic measurements

    Science.gov (United States)

    Lademann, Juergen; Weigmann, Hans-Juergen

    1995-01-01

    Toxic and carcinogenic substances were produced during laser application in medicine for the cutting and evaporation of tissue. The laser smoke presents a danger potential for the medical staff and the patients. The laser tissue interaction process was investigated by means of laser spectroscopic measurements which give the possibility of measuring metastable molecular states directly as a prerequisite to understand and to influence fundamental laser tissue interaction processes in order to reduce the amount of harmful chemicals. Highly excited atomic and molecular states and free radicals (CN, OH, C2, CH, CH2) have been detected applying spontaneous and laser induced fluorescence methods. It was found that the formation of harmful substances in the laser plumes can be reduced significantly by optimization of the surrounding gas atmosphere. A high content of oxygen or water in the interaction zone has been found, in agreement with the results of classical and analytical methods, as a suitable way to decrease pollutant emission. The experimental methods and the principal results are applicable not only in laser medicine but in laser material treatment generally.

  19. Spectroscopic investigation on the interaction of salidroside with bovine serum albumin

    Science.gov (United States)

    Cheng, Zhengjun; Zhang, Yuntao

    2008-10-01

    This study is designed to examine the interaction of salidroside with bovine serum albumin (BSA) under physiological conditions with drug concentrations in the range of 1.67-20.0 μM. Spectroscopic analysis of the emission quenching at different temperatures has revealed that the quenching mechanism of salidroside with BSA is static quenching mechanism. The calculated distance r between salidroside and the protein is evaluated according to the theory of Forster energy transfer. The results of FTIR, CD, synchronous fluorescence spectra and UV-vis absorption spectra experiment show that the secondary structures of the protein has been changed in the presence of salidroside. The thermodynamic parameters, enthalpy change (Δ H0) and entropy change (Δ S0) are calculated to be -50.50 kJ mol -1 and -59.13 J mol -1 K -1according to van't Hoff equation, which indicate that the hydrogen bonds and van der Waals forces are the intermolecular force stabilizing the complex. The effects of common ions on the binding constants of BSA-salidroside complexes were also investigated.

  20. Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line

    OpenAIRE

    Cheng, X; Ding, M. D.

    2016-01-01

    In this Letter, we present Interface Region Imaging Spectrograph Fe XXI 1354.08 A forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of $\\ge$1000 km s$^{-1}$ and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The EUV images at the 131 A and 94 A passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot c...

  1. Investigation of the selenium metabolism in cancer cell lines.

    Science.gov (United States)

    Lunøe, Kristoffer; Gabel-Jensen, Charlotte; Stürup, Stefan; Andresen, Lars; Skov, Søren; Gammelgaard, Bente

    2011-02-01

    The aim of this work was to compare different selenium species for their ability to induce cell death in different cancer cell lines, while investigating the underlying chemistry by speciation analysis. A prostate cancer cell line (PC-3), a colon cancer cell line (HT-29) and a leukaemia cell line (Jurkat E6-1) were incubated with five selenium compounds representing inorganic as well as organic Se compounds in different oxidation states. Selenomethionine (SeMet), Se-methylselenocysteine (MeSeCys), methylseleninic acid (MeSeA), selenite and selenate in the concentration range 5-100 μM were incubated with cells for 24 h and the induction of cell death was measured using flow cytometry. The amounts of total selenium in cell medium, cell lysate and the insoluble fractions was determined by ICP-MS. Speciation analysis of cellular fractions was performed by reversed phase, anion exchange and size exclusion chromatography and ICP-MS detection. The selenium compounds exhibited large differences in their ability to induce cell death in the three cell lines and the susceptibilities of the cell lines were different. Full recovery of selenium in the cellular fractions was observed for all Se compounds except MeSeA. Speciation analysis showed that MeSeA was completely transformed during the incubations, while metabolic conversion of the other Se compounds was limited. Production of volatile dimethyl diselenide was observed for MeSeA and MeSeCys. MeSeA, MeSeCys and selenite showed noticeable protein binding. Correlations between cell death induction and the Se compounds transformations could not be demonstrated.

  2. Thiazole-based nitrogen mustards: Design, synthesis, spectroscopic studies, DFT calculation, molecular docking, and antiproliferative activity against selected human cancer cell lines

    Science.gov (United States)

    Łączkowski, Krzysztof Z.; Świtalska, Marta; Baranowska-Łączkowska, Angelika; Plech, Tomasz; Paneth, Agata; Misiura, Konrad; Wietrzyk, Joanna; Czaplińska, Barbara; Mrozek-Wilczkiewicz, Anna; Malarz, Katarzyna; Musioł, Robert; Grela, Izabela

    2016-09-01

    Synthesis, characterization and investigation of antiproliferative activity of ten thiazole-based nitrogen mustard against human cancer cells lines (MV4-11, A549, MCF-7 and HCT116) and normal mouse fibroblast (BALB/3T3) is presented. The structures of novel compounds were determined using 1H and 13C NMR, FAB(+)-MS, and elemental analyses. Among the derivatives, 5b, 5c, 5e, 5f and 5i were found to exhibit high activity against human leukaemia MV4-11 cells with IC50 values of 2.17-4.26 μg/ml. The cytotoxic activity of compound 5c and 5f against BALB/3T3 cells is up to 20 times lower than against cancer cell lines. Our results also show that compounds 5e and 5i have very strong activity against MCF-7 and HCT116 with IC50 values of 3.02-4.13 μg/ml. Moreover, spectroscopic characterization and cellular localization for selected compound were performed. In order to identify potential drug targets we perform computer simulations with DNA-binding site of hTopoI and hTopoII and quantum chemical calculation of interaction and binding energies in complexes of the five most active compounds with guanine.

  3. Investigating on-line pornography at the University of Johannesburg

    Directory of Open Access Journals (Sweden)

    P. Laughton

    2008-01-01

    Full Text Available The on-line user of today has access to a vast collection of information resources. In addition, the developments in Internet and Web technologies have made it even easier for surfers to anonymously get access to on-line pornography. The purpose of this research was to investigate the extent to which access to on-line pornography at the University of Johannesburg can be managed. For the empirical part of this research 1037 questionnaires were proportionally distributed to and completed by students on all five campuses of the university. The questionnaire consisted of four sections: biographical information; university computer facility usage; university acceptable use policy; and personal experience with university computer facilities. The gender distribution for the sample was almost even, with a total of 49,4% male participants and 50,6% female, with the largest grouping of respondents (61,6% aged between 19 years and 21 years. Of the respondents, 36,7% indicated that exposure to unsolicited pornography did not bother them. When asked to what extent students should have access to pornography, 60,5% stated 'None' while 32,6% believed that 'Restricted' access should be granted for research purposes and 6,9% believed that students should be granted 'Total' access to pornography. Results from the research will be used to manage access to on-line resources at the University of Johannesburg better.

  4. Investigating on-line pornography at the University of Johannesburg

    Directory of Open Access Journals (Sweden)

    P. Laughton

    2007-12-01

    Full Text Available The on-line user of today has access to a vast collection of information resources. In addition, the developments in Internet and Web technologies have made it even easier for surfers to anonymously get access to on-line pornography. The purpose of this research was to investigate the extent to which access to on-line pornography at the University of Johannesburg can be managed. For the empirical part of this research 1037 questionnaires were proportionally distributed to and completed by students on all five campuses of the university. The questionnaire consisted of four sections: biographical information; university computer facility usage; university acceptable use policy; and personal experience with university computer facilities. The gender distribution for the sample was almost even, with total of 49,4% male participants and 50,6% female, with the largest grouping of respondents(61,6% aged between 19 years and 21 years. Of the respondents, 36,7% indicated that exposure to unsolicited pornography did not bother them. When asked to what extent students should have access to pornography, 60,5% stated 'None' while 32,6% believed that 'Restricted' access should be granted for research purposes and 6,9% believed that students should be granted 'Total' access to pornography. Results from the research will be used to manage access to on-line resources at the University of Johannesburg better.

  5. 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

  6. NON-INVASIVE SPECTROSCOPIC ON-LINE METHODS TO MONITOR INDUSTRIAL PROCESSES

    DEFF Research Database (Denmark)

    Brooker, M. H.; Berg, Rolf W.

    2003-01-01

    Vibrational spectroscopy can be used to identify and establish concentrations of many common molecules and complex ions over a wide range of concentrations and conditions. Advances in CCD detection devices, notch-filters, lasers, micro- and fiber-optics have made it possible to use infrared and R......, studied with non-invasive Raman spectroscopy), and finally a discussion of some recent advances in experimental methods that make it possible to use Raman and infrared spectroscopy for on line analyses in some industrial applications.......Vibrational spectroscopy can be used to identify and establish concentrations of many common molecules and complex ions over a wide range of concentrations and conditions. Advances in CCD detection devices, notch-filters, lasers, micro- and fiber-optics have made it possible to use infrared...

  7. Stark-effect investigations of the sodium D2 line

    Science.gov (United States)

    Windholz, L.; Musso, M.

    1989-03-01

    The Stark effect of the sodium D2 line was investigated by use of high-resolution laser-atomic-beam spectroscopy. The shift and splitting of the hyperfine components of the line could be obtained and compared with theoretical calculations. This allows the determination of the scalar and tensor polarizabilities with high accuracy to be 49.28(15) and -21.97(10) kHz/(kV/cm)2, respectively. These values are compared with semiempirical calculated polarizabilities. Additionally, the behavior of the relative intensity of the components could be studied. In fields greater than 100 kV/cm, the two groups of components with MJ=(1/2 and (3/2 are widely separated and the pattern of each group is independent from the field strength, showing an ``electrical'' Paschen-Back effect. The relative intensities agree satisfactorily with the computations.

  8. Investigation of luminescence and spectroscopic properties of Nd3+ions in cadmium alkali borate glasses

    Science.gov (United States)

    Mohan, Shaweta; Thind, Kulwant Singh

    2016-07-01

    Neodymium doped cadmium alkali borate glasses having composition 20CdOsbnd 20R2Osbnd 59.5H3BO3sbnd 0.5Nd2O3; (R = Li, Na and K) were prepared by conventional melt-quenching technique. The amorphous nature of the glasses was confirmed by X-ray diffraction studies. The physical properties such as density, refractive index, molar volume, rare earth ion concentration etc. were determined. Optical absorption and fluorescence spectra were recorded. The Judd-Ofelt theory was applied on the optical absorption spectra of the glasses to evaluate the three phenomenological intensity parameters Ω2, Ω4 and Ω6. These parameters were in turn used to predict the radiative properties such as the radiative transition probability (A), radiative lifetime (τR) and branching ratio (βR) for the fluorescent levels of Nd3+ ion in the present glass series. The lasing efficiency of the prepared glasses has been characterized by the spectroscopic quality factor (Ω4/Ω6), the value of which is in the range of 0.2-1.5, typical for Nd3+ in different laser hosts. The variation of Ω2 with the change in alkali oxide has been attributed to the changes in the asymmetry of the ligand field at the rare earth ion site. The shift of the hypersensitive bands, study of the oscillator strengths and the variation of the spectral profile of the transition 4I9/2 → 4F7/2 + 4S3/2 indicate a maximum covalency of Ndsbnd O bond for glass with potassium ions. From the fluorescence spectra, peak wavelength (λp), effective line widths (Δλeff) and stimulated emission cross-section (σp) have been obtained for the three transitions 4F3/2 → 4I9/2,4F3/2 → 4I11/2 and4F3/2 → 4I13/2 of Nd3+ ion. The relatively high values of σp obtained for Nd3+ in present glass system suggest that these materials can be considered as suitable candidates for laser applications. The glass with potassium ions shows the highest value of the stimulated emission cross-section.

  9. 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

  10. 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

  11. A Spectroscopic Study of Nuclear Processing and Production of Anomalously Strong Lines in the Crab Nebula

    CERN Document Server

    MacAlpine, G M; Lester, W R; Vanderveer, S J; Strolger, L G

    2006-01-01

    We present and discuss correlations for optical and near-infrared (5500-10030 angstroms) line intensity measurements at many positions in the Crab Nebula. These correlations suggest the existence of gas produced by a range of nuclear processing, from material in which synthesis ended with the CNO-cycle, to some helium-burning and nitrogen depletion, to regions containing enriched products of oxygen-burning. The latter exhibit a gradual, linear rise of [Ni II] emission with increasing argon enrichment, whereas gas with less nuclear processing shows markedly different [Ni II] emission characteristics, including the highest derived abundances. This suggests two origins for stable, neutron-rich nickel in the nebula: a type of "alpha-rich freezeout" in the more highly processed material, and possibly removal of ions from the neutron star in other regions. In addition, the data indicate that anomalously strong observed [C I] emission comes from broad, low-ionization zones. Although the strongest He I emission could...

  12. 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.

  13. 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.)

  14. Spectroscopic investigation on europium doped heavy metal borate glasses for red luminescent application

    Science.gov (United States)

    Hegde, Vinod; Wagh, Akshatha; Hegde, Hemanth; Vishwanath, C. S. Dwaraka; Kamath, Sudha D.

    2017-05-01

    The present study explores a new borate family glasses based on 10ZnO-5Na2O-10Bi2O3-(75 - x) B2O3- xEu2O3 ( 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 Eu3+ concentration. XRD confirmed amorphous nature of the glasses. FTIR spectra in the absorption mode were recorded in the 400-4000 cm-1 region to identify different functional groups in the glass matrix. Deconvoluted FTIR spectra showed increase in BO4 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 (Ω2,Ω4) 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 Eu3+ ions doped ZnNaBiB glasses showed optimum performance and are potential candidate for red light generation at 613 nm.

  15. The ESO WFI Slitless Spectroscopic Survey of Hα Emission-Line Stars in the MW, LMC, and SMC

    Science.gov (United States)

    Martayan, C.; Aguayo, G.; Baade, D.; Fabregat, J.; Garrido, H.; Rivinius, T.; Stefl, S.

    2015-05-01

    The ESO Wide Field Imager (WFI) at the 2.2m on La Silla was used with its slitless facility to do a survey of the H-alpha emission-line stars (ELS) in the Magellanic Clouds and in two Galactic open clusters. About 8 million spectra were obtained in the LMC and SMC in less than 2 nights, highlighting that the WFI in slitless mode is an efficient instrument for such a spectroscopic survey. In the coming sections, we briefly describe the observations, the data reduction, and the analysis processes of this specific mode of WFI imagers, with examples from the obtained Galactic and Magellanic observations. The results with the WFI-slitless survey in about 80 SMC open clusters of the ELS search, with a special emphasis on Be stars are then presented. The comparison of the frequency of Be stars among early B stars populations shows that they are 3 to 5 times more abundant in the SMC than in the Galaxy. This result is consistent with the metallicity gradient between those two galaxies, leading to lower angular momentum loss, then to faster rotational velocities, and therefore to more Be stars in the SMC. Finally, the first results of the ongoing studies in the LMC are briefly mentioned.

  16. 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

  17. An Investigation of the Nitrogen Line Strength Anomaly in on Stars.

    Science.gov (United States)

    Dumont, Philip J.

    The extremely strong nitrogen absorption line spectrum in ON. stars (Walborn, 1976) has been investigated. Coude' dispersion. (16 (ANGSTROM)/mm) spectroscopic data for two ON stars (HD201345 and. HD14633) and a group of normal O stars have been analyzed to determine the effective temperatures and surface gravities of these stars. Nitrogen equivalent widths have also been measured from the data for each star. The nitrogen spectrum has been theoretically modelled by a non-Local Thermodynamic Equilibrium (non-LTE) spectrum synthesis using an algorithm based on the "Complete Linearization Method" of Auer and Mihalas (1969). Two model atoms have been constructed and used to predict equivalent widths for the nitrogen absorption lines N III 3p ('2)P('0) ( --->) 3d ('2)D (lamda)4634, (lamda)4640, (lamda)4641; N III 4d ('2)D (--->) 5f(' 2)F('0) (lamda)3999, (lamda)4004; and N III 4f ('2)F('0) (--->) 5g(' 2)G (lamda)4379. The theoretical results have been synthesized in Mihalas (1972) non-LTE model atmospheres for several nitrogen abundances at each point in a grid of effective temperature and surface gravity. Theoretical nitrogen equivalent widths for each abundance have been interpolated to the effective temperature and surface gravity appropriate to each star. The measured nitrogen equivalent widths have been compared to the theoretical equivalent widths to determine a nitrogen abundance for each star. The abundance by number, relative to hydrogen (N/H), determined for HD201345 is:. N/H(HD201345) = 2.4 x 10('-2) (+OR-) 9.6 x 10(' -3). The abundance determined from HD14633 is:. N/H(HD14633) = 1.5 x 10('-2) (+OR-) 1.9 x 10(' -2). The average nitrogen abundance derived for the group of normal O stars is:. N/H(normal O stars) = 1.0 x 10('-4) (+OR-) 5.9 x 10('-5). This investigation concludes that the nitrogen line spectroscopic anomaly in ON stars is explained by an overabundance of nitrogen in the atmospheres of these stars.

  18. Investigation of the interaction of naringin palmitate with bovine serum albumin: spectroscopic analysis and molecular docking.

    Directory of Open Access Journals (Sweden)

    Xia Zhang

    Full Text Available BACKGROUND: Bovine serum albumin (BSA contains high affinity binding sites for several endogenous and exogenous compounds and has been used to replace human serum albumin (HSA, as these two compounds share a similar structure. Naringin palmitate is a modified product of naringin that is produced by an acylation reaction with palmitic acid, which is considered to be an effective substance for enhancing naringin lipophilicity. In this study, the interaction of naringin palmitate with BSA was characterised by spectroscopic and molecular docking techniques. METHODOLOGY/PRINCIPAL FINDINGS: The goal of this study was to investigate the interactions between naringin palmitate and BSA under physiological conditions, and differences in naringin and naringin palmitate affinities for BSA were further compared and analysed. The formation of naringin palmitate-BSA was revealed by fluorescence quenching, and the Stern-Volmer quenching constant (KSV was found to decrease with increasing temperature, suggesting that a static quenching mechanism was involved. The changes in enthalpy (ΔH and entropy (ΔS for the interaction were detected at -4.11 ± 0.18 kJ·mol(-1 and -76.59 ± 0.32 J·mol(-1·K(-1, respectively, which indicated that the naringin palmitate-BSA interaction occurred mainly through van der Waals forces and hydrogen bond formation. The negative free energy change (ΔG values of naringin palmitate at different temperatures suggested a spontaneous interaction. Circular dichroism studies revealed that the α-helical content of BSA decreased after interacting with naringin palmitate. Displacement studies suggested that naringin palmitate was partially bound to site I (subdomain IIA of the BSA, which was also substantiated by the molecular docking studies. CONCLUSIONS/SIGNIFICANCE: In conclusion, naringin palmitate was transported by BSA and was easily removed afterwards. As a consequence, an extension of naringin applications for use in food, cosmetic

  19. 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

  20. 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

  1. Employment of different spectroscopic tools for the investigation of chromium(VI) oxidation of acetaldehyde in aqueous micellar medium

    Indian Academy of Sciences (India)

    SUSANTA MALIK; ANIRUDDHA GHOSH; PINTU SAR; MONOHAR HOSSAIN MONDAL; KALACHAND MAHALI; BIDYUT SAHA

    2017-05-01

    Different spectroscopic methods have been applied to investigate the chromic acid oxidation of acetaldehyde in aqueous media, catalysed by surfactants. Three representative heteroaromatic nitrogen base promoters, 2-picolinic acid (PA), 2,2’-bipyridine (bpy) and 1,10-phenanthroline (phen), have been associated along with surfactants as promoters to the kinetic study. Comparative studies of unpromoted and promoted reactions invoked that 2,2’-bipyridine produced maximum rate enhancement. The mechanism of the reaction path has been proposed with the help of kinetic results and spectroscopic studies. The observed net enhancementof rate effects has been explained with scientific manipulations and data obtained. The combination of TX-100 and1,10-phenanthroline is found to be most effective for acetaldehyde oxidation.

  2. Candidate Water Vapor Lines to Locate the H$_{2}$O Snowline through High-Dispersion Spectroscopic Observations I. The Case of a T Tauri Star

    CERN Document Server

    Notsu, Shota; Ishimoto, Daiki; Walsh, Catherine; Honda, Mitsuhiko; Hirota, Tomoya; Millar, T J

    2016-01-01

    Inside the H$_{2}$O snowline of protoplanetary disks, water evaporates from the dust-grain surface into the gas phase, whereas it is frozen out on to the dust in the cold region beyond the snowline. H$_{2}$O ice enhances the solid material in the cold outer part of a disk, which promotes the formation of gas-giant planet cores. We can regard the H$_{2}$O snowline as the surface that divides the regions between rocky and gaseous giant planet formation. Thus observationally measuring the location of the H$_{2}$O snowline is crucial for understanding the planetesimal and planet formation processes, and the origin of water on Earth. In this paper, we find candidate water lines to locate the H$_{2}$O snowline through future high-dispersion spectroscopic observations. First, we calculate the chemical composition of the disk and investigate the abundance distributions of H$_{2}$O gas and ice, and the position of the H$_{2}$O snowline. We confirm that the abundance of H$_{2}$O gas is high not only in the hot midplane...

  3. Spectroscopic investigation of native defect induced electron-phonon coupling in GaN nanowires

    Science.gov (United States)

    Parida, Santanu; Patsha, Avinash; Bera, Santanu; Dhara, Sandip

    2017-07-01

    The integration of advanced optoelectronic properties in nanoscale devices of group III nitride can be realized by understanding the coupling of charge carriers with optical excitations in these nanostructures. The native defect induced electron-phonon coupling in GaN nanowires are reported using various spectroscopic studies. The GaN nanowires having different native defects are grown in an atmospheric pressure chemical vapor deposition technique. X-ray photoelectron spectroscopic analysis revealed the variation of Ga/N ratios in nanowires having possible native defects, with respect to their growth parameters. The analysis of the characteristic features of electron-phonon coupling in the Raman spectra show the variations in carrier density and mobility, with respect to the native defects in unintentionally doped GaN nanowires. The radiative recombination of donor acceptor pair transitions and the corresponding LO phonon replicas observed in photoluminescence studies further emphasize the role of native defects in electron-phonon coupling.

  4. Multi-spectroscopic methods investigation on the interaction of tenoxicam with DNA.

    Science.gov (United States)

    Liu, Bing-Mi; Zhang, Jun; Liu, Yang; Zhang, Li-Ping; Ma, Ping; Wang, Xin; Liu, Bin

    2015-12-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) show chemopreventive and chemosuppressive effects on various cancer cell lines. They exert anticancer activities by inhibiting both at the protein level and/or at the transcription level. Thus, in this paper, the interaction between tenoxicam (TXM) and calf thymus DNA (ct-DNA) was investigated by UV-visible light, fluorescence, viscosity experiments and DNA melting studies. The results showed that TXM could bind to ct-DNA in the groove binding mode. The binding constants were 7.67 × 10(3) and 5.48 × 10(3) M(-1) at 293 and 300 K, respectively. Furthermore, the calculated thermodynamic parameters suggested that hydrogen bonds or van der Waals force might play an important role in the binding of TXM to ct-DNA. The obtained results should give new insight into the pharmacological activity of TXM.

  5. [Application of Raman spectroscopic technique to the identification and investigation of Chinese ancient jades and jade artifacts].

    Science.gov (United States)

    Zhao, Hong-Xia; Gan, Fu-Xi

    2009-11-01

    Laser Raman spectroscopic technique is one of the essential methods in scientific archaeological research, which belongs to the nondestructive analysis. As a very good nondestructive analysis approach, it has not been widely applied in the research of the Chinese ancient jade artifacts. First of all in the present paper the fundamentals of laser Raman spectroscopic technique and the new research progress in this field were reviewed. Secondly, the Raman spectra of five familiar jades including nephrite (mainly composed of tremolite), Xiuyan Jade (mainly composed of serpentine), Dushan Jade (mainly composed of anorthite and Zoisite), turquoise and lapis lazuli were summarized respectively. As for an example, the Raman spectra of the four Chinese ancient jade artifacts excavated from Liangzhu Site of Zhejiang Province and Yinxu Site of Anyang in Henan Province were compared with that of the nephrite sample in Hetian of Xinjiang Province. It was shown that the Raman spectroscopic technique is a good nondestructive approach to the identification and investigation of the structures and mineral composition of Chinese ancient jade artifacts. Finally, the limitations and the foreground of this technique were discussed.

  6. High-speed intravascular spectroscopic photoacoustic imaging at 1000 A-lines per second with a 0.9-mm diameter catheter

    Science.gov (United States)

    Li, Yan; Gong, Xiaojing; Liu, Chengbo; Lin, Riqiang; Hau, William; Bai, Xiaosong; Song, Liang

    2015-06-01

    Intravascular spectroscopic photoacoustic technology can image atherosclerotic plaque composition with high sensitivity and specificity, which is critical for identifying vulnerable plaques. Here, we designed and engineered a catheter of 0.9 mm in diameter for intravascular photoacoustic (IVPA) imaging, smaller than the critical size of 1 mm required for clinical translation. Further, a quasifocusing photoacoustic excitation scheme was developed for the catheter, producing well-detectable IVPA signals from stents and lipids with a laser energy as low as ˜30 μJ/pulse. As a result, this design enabled the use of a low-energy, high-repetition rate, ns-pulsed optical parametric oscillator laser for high-speed spectroscopic IVPA imaging at both the 1.2-μm and 1.7-μm spectral bands for lipid detection. Specifically, for each wavelength, a 1-kHz IVPA A-line rate was achieved, ˜100-fold faster than previously reported IVPA systems offering a similar wavelength tuning range. Using the system, spectroscopic IVPA imaging of peri-adventitial adipose tissue from a porcine aorta segment was demonstrated. The significantly improved imaging speed, together with the reduced catheter size and multiwavelength spectroscopic imaging ability, suggests that the developed high-speed IVPA technology is of great potential to be further translated for in vivo applications.

  7. DNA induced sequestration of a bioactive cationic fluorophore from the lipid environment: A spectroscopic investigation.

    Science.gov (United States)

    Ghosh, Saptarshi; Kundu, Pronab; Chattopadhyay, Nitin

    2016-01-01

    The effect of calf-thymus DNA (ctDNA) on the lipid bound probe, formed by the cationic phenazinium dye phenosafranin (PSF) and the anionic lipid dimyristoyl-L-α-phosphatidylglycerol (DMPG), has been unearthed exploiting various spectroscopic techniques. Steady state and time-resolved fluorometric studies and measurements of circular dichroism and DNA helix melting temperature reveal that in the presence of DNA the probe is dislodged from the lipid environment and gets intercalated within the DNA helix. The work qualitatively illustrates that the anionic lipid can be used as a potential nanocarrier for delivering the cationic drugs to the most relevant biomacromolecular target, DNA.

  8. Spectroscopic ellipsometry investigations of the optical properties of manganese doped bismuth vanadate thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kumari, Neelam; Krupanidhi, S.B. [Materials Research Center, Indian Institute of Science, Bangalore 560012 (India); Varma, K.B.R., E-mail: kbrvarma@mrc.iisc.ernet.in [Materials Research Center, Indian Institute of Science, Bangalore 560012 (India)

    2010-04-15

    The optical properties of Bi{sub 2}V{sub 1-x}Mn{sub x}O{sub 5.5-x} {l_brace}x = 0.05, 0.1, 0.15 and 0.2 at.%{r_brace} thin films fabricated by pulsed laser deposition on platinized silicon substrates were studied in UV-visible spectral region (1.51-4.17 eV) using spectroscopic ellipsometry. The optical constants and thicknesses of these films have been obtained by fitting the ellipsometric data ({Psi} and {Delta}) using a multilayer four-phase model system and a relaxed Lorentz oscillator dispersion relation. The surface roughness and film thickness obtained by spectroscopic ellipsometry were found to be consistent with the results obtained by atomic force and scanning electron microscopy. The refractive index measured at 650 nm does not show any marginal increase with Mn content. Further, the extinction coefficient does not show much decrease with increasing Mn content. An increase in optical band gap energy from 2.52 to 2.77 eV with increasing Mn content from x = 0.05 to 0.15 was attributed to the increase in oxygen ion vacancy disorder.

  9. Computational Investigation of the Los Alamos Magnetically Insulated Line Oscillator

    Science.gov (United States)

    Stringfield, Ray M.; Kares, Robert J.

    2001-10-01

    Numerical modeling has been performed using the particle-in-cell code ISIS to interpret earlier experimental investigations of a Magnetically Insulated Line Oscillator (MILO)*. Improvements in the experimental performance of the MILO attributed to interposing a plasma opening switch between the MILO structure and the downstream diode has been studied computationally. Pulsed power operating conditions examined were in the range of 400-600 kV, 50-150 kA, in 1 microsecond electrical power pulses. A downstream post-hole convolute diode load controlled the overall operating impedance of the system to match the average E/B velocity of the vacuum flowing electrons to the MILO resonance conditions. Two nominal MILO operating impedances were studied: 3 and 6 ohms. The 6 ohm geometry was a better impedance match to the the Marx pulse power generator and provided RF pulses greater than 600 ns. *R. M. Stringfield,et al, Bul. Am. Phys. Soc. Vol 33, No. 9, October, 1988, p1959.

  10. Spectroscopic investigations of dispersion-shifted fiber with thin active Bi-doped ring and high nonlinear refractive index

    Science.gov (United States)

    Zlenko, A. S.; Akhmetshin, U. G.; Bogatyrjov, V. A.; Bulatov, L. I.; Dvoyrin, V. V.; Firstov, S. V.; Dianov, E. M.

    2009-10-01

    A germanium-doped silica-core fiber with an active region in the form of a thin ring of silica doped with bismuth ions was fabricated. Bismuth doping in the ring surrounding the core allows to stabilize bismuth in silica glass, and it does not impose any restrictions on the composition of the core. The bismuth concentration in the ring is less than 0.2 wt.%. The GeO2 concentration in the core is more than 15 mol.%. A high germanium concentration in the core allows to shift the zero dispersion wavelength to 1860 nm and to obtain a high nonlinear refractive index (n2 more than 3,2*10-20 m2/W). Spectroscopic investigations were carried out in the visible and near infrared (800-1700 nm) spectral range. Despite the small concentration of bismuth, we observed the absorption and luminescence characteristic bands, confirming the presence of bismuth active centers in silica glass. Upon pumping at 1350 nm the on/off gain spectrum was measured on a 20-m fiber. The gain was observed throughout investigated range of 1430-1530 nm. The maximal gain of ~9.5 dB was obtained near 1430 nm. The results of the spectroscopic investigations of the fiber with a thin active Bi-doped ring showed prospects of the creation and application of such fiber type for laser and nonlinear optics.

  11. 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

  12. The Sloan Digital Sky Survey Reverberation Mapping Project: An Investigation of Biases in C iv Emission Line Properties

    Science.gov (United States)

    Denney, K. D.; Horne, Keith; Shen, Yue; Brandt, W. N.; Ho, Luis C.; Peterson, B. M.; Richards, Gordon T.; Trump, J. R.; Ge, J.

    2016-06-01

    We investigate the dependence on data quality of quasar properties measured from the C iv emission line region at high redshifts. Our measurements come from 32 epochs of Sloan Digital Sky Survey Reverberation Mapping Project spectroscopic observations of 482 z\\gt 1.46 quasars. We compare the differences between measurements made from the single-epoch (SE) and coadded spectra, focusing on the C iv λ1549 emission line because of its importance for studies of high-redshift quasar demographics and physical properties, including black hole masses. In addition to statistical errors increasing (by factors of ˜2-4), we find increasing systematic offsets with decreasing signal-to-noise ratio (S/N). The systematic difference (measurement uncertainty) in our lowest-S/N ( 10, although offsets in lower-S/N spectra exceed the statistical uncertainties by only a factor of ˜1.5 and may depend on the type of functional fit to the line. Characterizing the C iv line profile by the kurtosis is the least robust property investigated, as the median systematic coadded-SE measurement differences are larger than the statistical uncertainties for all S/N subsamples.

  13. 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...... methods. For all proteins, immobilization causes a decrease in protein stability and a loosening of the helix packing, as reflected by a partial dissociation of a histidine ligand in the ferrous state and very low redox potentials. For the covalently attached MOP-C, the overall interfacial redox process...... involves the coupling of electron transfer and heme ligand dissociation, which was analyzed by time-resolved SERR spectroscopy. Electron transfer was found to be significantly slower for the mono-histidine-coordinated than for the bis-histidine-coordinated heme. For the latter, the formal heterogeneous...

  14. Investigation of effect of annealing on thermally evaporated ZnSe thin films through spectroscopic techniques

    Science.gov (United States)

    Mahesha, M. G.; Rashmitha; Meghana, N.; Padiyar, Meghavarsha

    2017-09-01

    ZnSe thin films have been grown on clean glass substrates by thermal evaporation technique and deposited films have been annealed at 473 K. William-Hall method has been adopted to extract information on crystallite size and internal strain in the film from X-ray diffractogram. Effect of annealing on ZnSe films has been analyzed by spectroscopic techniques which include optical absorption, Raman, and photoluminescence spectroscopy. From optical absorption, band gap has been estimated along with other optical parameters like refractive index and extinction coefficient. Also, Urbach tail, which originates near bad edge due to structural disorders, has been characterized. Raman spectra have been analyzed to get the information on the influence of crystallite size and strain effect on peak position, intensity and width. Photoluminescence spectra have been recorded and analyzed to get an insight on defect levels induced due to vacancies, interstadials, and impurity complexes.

  15. 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.

  16. Efficient ultrasound-assisted synthesis, spectroscopic, crystallographic and biological investigations of pyrazole-appended quinolinyl chalcones

    Science.gov (United States)

    Prasath, R.; Bhavana, P.; Sarveswari, S.; Ng, Seik Weng; Tiekink, Edward R. T.

    2015-02-01

    Two series of new quinolinyl chalcones containing a pyrazole group, 3a-f and 4a-r, have been synthesized by Claisen-Schmidt condensation of the derivatives of 2-methyl-3-acetylquinoline with either substituted 1,3-diphenyl-1H-pyrazole-4-carbaldehyde or 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde in 76-93% yield under ultrasonic method. The compounds were characterized using IR, 1H NMR and ESI-MS spectroscopic methods and, for representative compounds, by X-ray crystallography. An E-configuration about the Cdbnd C ethylene bond has been established via 1H NMR spectroscopy and X-ray crystallography. These compounds show promising anti-microbial properties, with 4a and 3e being the most potent against bacterial and fungal strains, respectively and the methoxy substituted compounds showed moderate anti-oxidant activity.

  17. Spectroscopic investigation on the interaction of maslinic acid with bovine serum albumin

    Energy Technology Data Exchange (ETDEWEB)

    Molina-Bolívar, J.A., E-mail: jmb@uma.es [Department of Applied Physics II, Engineering School, University of Málaga, 29071 Málaga (Spain); Galisteo-González, F. [Department of Applied Physics, University of Granada, 18071 Granada (Spain); Carnero Ruiz, C. [Department of Applied Physics II, Engineering School, University of Málaga, 29071 Málaga (Spain); Medina-O' Donnell, M.; Parra, A. [Department of Organic Chemistry, University of Granada, 18071 Granada (Spain)

    2014-12-15

    Ultraviolet–visible (UV–vis), steady-state and time-resolved fluorescence, and Fourier transform-infrared (FT-IR) spectroscopy were used to study the interaction between maslinic acid (MA) and bovine serum albumin (BSA). Binding constants were determined at three different temperatures (298, 304, and 310 K). Spectroscopic analysis revealed that the fluorescence-quenching mechanism between MA and BSA was a static quenching procedure. MA specifically binds to one site of the BSA molecule forming a stable complex with a binding constant of (5.4±0.4)×10{sup 4} M{sup −1} at pH 7.4 and 298 K. From the thermodynamic parameters of the binding process (ΔG{sup 0}, ΔH{sup 0} and ΔS{sup 0}) it can be inferred that hydrogen bonds and van der Waals interactions are the predominant intermolecular forces responsible for the stabilization of the complex. Anisotropy studies revealed that tryptophan residues of BSA undergo motion restrictions as a result of the interaction with MA. The distance between MA and the fluorophore residue of BSA was evaluated according to the theory of Föster for fluorescence resonance energy transfer (FRET). Observations from FT-IR spectra and three-dimensional fluorescence indicated changes in the conformation of BSA upon ligand binding. - Highlights: • The interaction between MA and BSA was examined with spectroscopic techniques. • The interaction between MA and BSA was studied at different temperatures. • Fluorescence spectroscopy studies suggest that quenching mechanism is static. • The hydrogen bonds and van der Waals interactions are predominant forces. • Conformational changes of the protein upon binding of MA were observed.

  18. Infrared spectroscopic investigations of environmental deNOx and hydrotreating catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Topsoee, Nan-Yu

    1998-02-01

    The present work describes the application of infrared spectroscopy to the investigation of two very important of environmental catalyst systems, i.e. vanadia/titania catalysts for the selective catalytic reduction (SCR) of NOx by ammonia and molybdena/alumina catalyst systems for sulfur removal and other hydrotreating reactions. It is seen that the infrared studies have provided new insight into the surface structures present in the catalyst systems. Furthermore, and more importantly the results have made it possible to establish direct relationships between the fundamental molecular properties and the industrial performance. For these studies the application of a variety of different steady-state and transient FTIR techniques/approaches is shown to be very important. Infrared spectroscopy is one of the few techniques which can provide in situ surface information about real catalysts. Vanadia/titania deNOx catalysts are discussed. The reactivity of various surface species is discussed further based on transient temperature programmed surface reaction (TPSR) studies employing a combined in situ FTIR on-line mass spectrometric approach. The studies are performed by exposing different catalysts with chemisorbed NH{sub 3} to various reaction gases. Part II deals with the studies of hydrotreating catalysts. The catalysts (typically Co-Mo/Al{sub 2}O{sub 3} and Ni-Mo/Al{sub 2}O{sub 3}) are normally prepared in the oxidic (calcined) state but requires sulfiding in order to become activated. The infrared investigation of calcined alumina supported catalysts is discussed. The alumina support has a number of very specific hydroxyl groups. Mo is seen to interact with these groups resulting in the formation of monolayer-type structures bonded to the support via Mo-O-Al bridges. The monolayer structures are seen to be restricted to the original hydroxyl part of the alumina surface. It is seen that there is a preference for Mo to interact with the most basic Al-OH groups and

  19. 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.)

  20. Dipodal quinoline-tethered fluorescent probe synthesis and investigation of spectroscopic properties

    Science.gov (United States)

    Obalı, Aslıhan Yılmaz; Yilmaz, Menzeher Serkan; Uçan, Halil İsmet

    2017-10-01

    Novel quinoline-tethered fluorescent probe was designed and synthesized as multidentate ligand. Their sensing actions were confirmed by UV-Vis absorbance and emission spectroscopic studies in presence of perchlorate salts of Co2+, Li+, Fe2+, K+, Pb2+, Cu2+, Zn2+, Ni2+, Hg2+, Ag+ cations in acetonitrile (1 × 10-5 M for absorption studies, 1 × 10-7 M for fluorescence studies). It was found that the dipodal compounds can selectively bind to Cu2+ and Ag+ metal ions with a significant quenching in their emissions. The capture of Cu2+ and Ag+ by the probe resulted in deprotonation of the secondary amine conjugated to the quinoline-tethered probe, so that the electron-donation ability of the 'N' atom would be greatly enhanced and the probe (2) showed blue-shift in emission and exhibited an on-off fluorescent response. The binding study was explored by using fluorescence spectroscopy with Job plot method.

  1. Investigation of the interaction between berberine and nucleosomes in solution: Spectroscopic and equilibrium dialysis approach

    Science.gov (United States)

    Rabbani-Chadegani, Azra; Mollaei, Hossein; Sargolzaei, Javad

    2017-02-01

    Berberine is a natural plant alkaloid with high pharmacological potential. Although its interaction with free DNA has been the subject of several reports, to date there is no work concerning the effect of berberine on nucleoprotein structure of DNA, the nucleosomes. The present study focuses on the binding affinity of berberine to nucleosomes and histone H1 employing various spectroscopic techniques, fluorescence, circular dichroism, thermal denaturation as well as equilibrium dialysis. The results showed that the binding of berberine to nucleosomes is positive cooperative with Ka = 5.57 × 103 M- 1. Berberine quenched with the chromophores of protein moiety of nucleosomes and reduced fluorescence emission intensity at 335 nm with Ksv value of 0.135. Binding of berberine to nucleosomes decreased the absorbance at 210 and 260 nm, produced hypochromicity in thermal denaturation profiles and its affinity to nucleoprotein structure of nucleosomes was much higher than to free DNA. Berberine also exhibited high affinity to histone H1 in solution and the binding was positive cooperative with. Ka = 3.61 × 103 M- 1. Moreover berberine decreased fluorescence emission intensity of H1 by quenching with tyrosine residue in its globular core domain. The circular dichroism profiles demonstrated that the binding of drug induced secondary structural changes in both DNA stacking and histone H1. It is concluded that berberine is genotoxic drug, interacts with nucleosomes and in this process histone H1 is involved to exert its anticancer activity.

  2. Spectroscopic investigation and direct comparison of the reactivities of iron pyridyl oxidation catalysts

    Science.gov (United States)

    Song, Yang; Mayes, Howard G.; Queensen, Matthew J.; Bauer, Eike B.; Dupureur, Cynthia M.

    2017-03-01

    The growing interest in green chemistry has fueled attention to the development and characterization of effective iron complex oxidation catalysts. A number of iron complexes are known to catalyze the oxidation of organic substrates utilizing peroxides as the oxidant. Their development is complicated by a lack of direct comparison of the reactivities of the iron complexes. To begin to correlate reactivity with structural elements, we compare the reactivities of a series of iron pyridyl complexes toward a single dye substrate, malachite green (MG), for which colorless oxidation products are established. Complexes with tetradentate, nitrogen-based ligands with cis open coordination sites were found to be the most reactive. While some complexes reflect sensitivity to different peroxides, others are similarly reactive with either H2O2 or tBuOOH, which suggests some mechanistic distinctions. [Fe(S,S-PDP)(CH3CN)2](SbF6)2 and [Fe(OTf)2(tpa)] transition under the oxidative reaction conditions to a single intermediate at a rate that exceeds dye degradation (PDP = bis(pyridin-2-ylmethyl) bipyrrolidine; tpa = tris(2-pyridylmethyl)amine). For the less reactive [Fe(OTf)2(dpa)] (dpa = dipicolylamine), this reaction occurs on a timescale similar to that of MG oxidation. Thus, the spectroscopic method presented herein provides information about the efficiency and mechanism of iron catalyzed oxidation reactions as well as about potential oxidative catalyst decomposition and chemical changes of the catalyst before or during the oxidation reaction.

  3. A Spectroscopic Investigation on the Structural Evolution of Soy Based Polyurethane Foams

    Science.gov (United States)

    Puthanparambil, Deepa; Kimball, Casey; Hsu, Shaw L.

    2009-03-01

    Our current research deals with an economical and renewable soy based polyol for use in polyurethane foams. Infrared spectroscopic studies have revealed that the amount of polyurea segments formed and the kinetics of their formation in soy based polyurethane foam systems are considerably different from traditional systems employing ethylene oxide -- propylene oxide based polyols. The most crucial aspect of this research deals with the miscibility of water in the reactive mixtures involving extremely hydrophobic soy-based polyols. High Field Nuclear Magnetic Resonance Spectroscopy (NMR) with D2O as the probing agent was employed to determine the miscibility behavior at the molecular level. This technique was able to establish the structure and location of dispersed water, which can be extremely different based on the polyols used, thus affecting the morphology of the foam. The length and amount of polyureas directly impact the kinetics of the phase separation process to form the hard-segment rich domains and associated physical properties. The aggregation of these polyurea hard domains were characterized by the hydrogen bonds formed. This structural transformation as a function of reaction is also reflected in the segmental relaxation kinetics characterized by spin-spin diffusion, measured using a low field NMR instrument.

  4. IR spectroscopic investigation of the inhibition of the glycation process by acetylsalicylic acid

    Science.gov (United States)

    Otero de Joshi, Virginia; Gil, Herminia; Contreras, Silvia; Velasquez, William; Joshi, Narahari V.

    2000-05-01

    An IR spectroscopic study was carried out at room temperature for Human Serum albumin (HSA) glycated with fructose and glucose and inhibited with acetylsalicylic acid. The glycation process was carried out in our laboratory by a conventional method to confirm earlier reported observation of the effect of glycation on the intensity variation of the IR spectra, particularly, in the range 1500 cm-1 to 1700 cm-1 and around 3300 cm-1. IR spectra reveal that the effects of glycation of HSA by fructose are more intense than with glucose, which is the expected. Bovine serum albumin was also glycated using Glucose-6-phosphate disodium salt, and gamma-globulin was glycate with glucose, As expected, the glycation process was more intense with glucose-t-phosphate disodium salt. Acetyl salicylic acid was also used and its inhibitor effects could be observed in both cases, with glucose and with glucose-6-phosphate disodium salt even though, to a smaller extent with the latter. This is consistent with the earlier data and is explained on the basis of the attachment of macromolecules to (epsilon) -NH2 groups of lysines. The experimental results confirm that acetylsalicylic acid, indeed, acts as an inhibitor by acetylation of the (epsilon) -NG2 group where the sugars are supposed to be attached.

  5. 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.

  6. PROBING THE PHYSICS OF NARROW LINE REGIONS IN ACTIVE GALAXIES. II. THE SIDING SPRING SOUTHERN SEYFERT SPECTROSCOPIC SNAPSHOT SURVEY (S7)

    Energy Technology Data Exchange (ETDEWEB)

    Dopita, Michael A.; Davies, Rebecca; Kewley, Lisa; Hampton, Elise; Sutherland, Ralph [RSAA, Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia); Shastri, Prajval; Kharb, Preeti; Jose, Jessy; Bhatt, Harish; Ramya, S. [Indian Institute of Astrophysics, Koramangala 2 B Block, Bangalore 560034 (India); Scharwächter, Julia [LERMA, Observatoire de Paris, CNRS, UMR 8112, 61 Avenue de l’Observatoire, F-75014 Paris (France); Jin, Chichuan [Qian Xuesen Laboratory for Space Technology, Beijing (China); Banfield, Julie [CSIRO Astronomy and Space Science, P.O. Box 76, Epping NSW, 1710 Australia (Australia); Zaw, Ingyin [New York University (Abu Dhabi), 70 Washington Square South, New York, NY 10012 (United States); Juneau, Stéphanie [CEA-Saclay, DSM/IRFU/SAp, F-91191 Gif-sur-Yvette (France); James, Bethan [Institute of Astronomy, Cambridge University, Madingley Road, Cambridge CB3 0HA (United Kingdom); Srivastava, Shweta, E-mail: Michael.Dopita@anu.edu.au [Astronomy and Astrophysics Division, Physical Research Laboratory, Ahmedabad 380009 (India)

    2015-03-15

    Here we describe the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7) and present results on 64 galaxies drawn from the first data release. The S7 uses the Wide Field Spectrograph mounted on the ANU 2.3 m telescope located at the Siding Spring Observatory to deliver an integral field of 38 × 25 arcsec at a spectral resolution of R = 7000 in the red (530–710 nm), and R = 3000 in the blue (340–560 nm). From these data cubes we have extracted the narrow-line region spectra from a 4 arcsec aperture centered on the nucleus. We also determine the Hβ and [O iii] λ5007 fluxes in the narrow lines, the nuclear reddening, the reddening-corrected relative intensities of the observed emission lines, and the Hβ and [O iii] λ5007 luminosities determined from spectra for which the stellar continuum has been removed. We present a set of images of the galaxies in [O iii] λ5007, [N ii] λ6584, and Hα, which serve to delineate the spatial extent of the extended narrow-line region and also to reveal the structure and morphology of the surrounding H ii regions. Finally, we provide a preliminary discussion of those Seyfert 1 and Seyfert 2 galaxies that display coronal emission lines in order to explore the origin of these lines.

  7. ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: Search for [CII] line and dust emission in $6

    CERN Document Server

    Aravena, Manuel; Walter, Fabian; Bouwens, Rychard; Oesch, Pascal; Carilli, Christopher; Bauer, Franz E; Da Cunha, Elisabete; Daddi, Emanuele; Gónzalez-López, Jorge; Ivison, R J; Riechers, Dominik; Smail, Ian R; Swinbank, Mark; Weiss, Axel; Anguita, Timo; Bacon, Roland; Bell, Eric; Bertoldi, Frank; Cortes, Paulo; Cox, Pierre; Hodge, Jacqueline; Ibar, Eduardo; Inami, Hanae; Infante, Leopoldo; Karim, Alexander; Magnelli, Benjamin; Ota, Kauzuaki; Popping, Gergö; van der Werf, Paul; Wagg, Jeffrey

    2016-01-01

    We present a search for [CII] line and dust continuum emission from optical dropout galaxies at $z>6$ using ASPECS, our ALMA Spectroscopic Survey in the Hubble Ultra-Deep Field (UDF). Our observations, which cover the frequency range $212-272$ GHz, encompass approximately the range $6$4.5 $\\sigma$, two of which correspond to blind detections with no optical counterparts. At this significance level, our statistical analysis shows that about 60\\% of our candidates are expected to be spurious. For one of our blindly selected [CII] line candidates, we tentatively detect the CO(6-5) line in our parallel 3-mm line scan. None of the line candidates are individually detected in the 1.2 mm continuum. A stack of all [CII] candidates results in a tentative detection with $S_{1.2mm}=14\\pm5\\mu$Jy. This implies a dust-obscured star formation rate (SFR) of $(3\\pm1)$ M$_\\odot$ yr$^{-1}$. We find that the two highest--SFR objects have candidate [CII] lines with luminosities that are consistent with the low-redshift $L_{\\rm [C...

  8. Investigating the spectroscopic, magnetic and circumstellar variability of the O9 subgiant star HD 57682

    NARCIS (Netherlands)

    J.H. Grunhut; G.A. Wade; J.O. Sundqvist; A. ud-Doula; C. Neiner; R. Ignace; W.L.F. Marcolino; T. Rivinius; A. Fullerton; L. Kaper; B. Mauclaire; C. Buil; T. Garrel; J. Ribeiro; S. Ubaud

    2012-01-01

    The O9IV star HD 57682, discovered to be magnetic within the context of the Magnetism in Massive Stars (MiMeS) survey in 2009, is one of only eight convincingly detected magnetic O-type stars. Among this select group, it stands out due to its sharp-lined photospheric spectrum. Since its discovery, t

  9. The Sloan Digital Sky Survey Reverberation Mapping Project: An Investigation of Biases in CIV Emission-Line Properties

    CERN Document Server

    Denney, K D; Brandt, W N; Ho, Luis C; Peterson, B M; Richards, Gordon T; Shen, Yue; Trump, J R; Ge, J

    2016-01-01

    We investigate the dependence on data quality of quasar properties measured from the CIV emission line region at high redshifts. Our measurements come from 32 epochs of Sloan Digital Sky Survey (SDSS) Reverberation Mapping Project spectroscopic observations of 482 z>1.46 quasars. We compare the differences between measurements made from the single-epoch and coadded spectra, focusing on the CIV emission line because of its importance for studies of high-redshift quasar demographics and physical properties, including black hole masses. In addition to statistical errors increasing (by factors of ~2-4), we find increasing systematic offsets with decreasing S/N. The systematic difference (measurement uncertainty) in our lowest S/N (10, although offsets in lower S/N spectra exceed the statistical uncertainties by only a factor of ~1.5. Characterizing the CIV line profile by the kurtosis is the least robust property investigated, as the median systematic coadded--single-epoch measurement differences are larger than ...

  10. Spectroscopic investigation of europium benzoate in acetonitrile: Luminescence enhancement and complexation studies

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Satendra; Maji, S. [Materials Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Joseph, M. [Fuel Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Sankaran, K., E-mail: ksran@igcar.gov.in [Materials Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2015-05-15

    Luminescence from Eu{sup 3+} complexed with benzoic acid (BA) has been studied using acetonitrile (MeCN) as solvent. More than two orders luminescence enhancement is found as compared to Eu{sup 3+}–BA complex in aqueous medium. The lifetime of Eu{sup 3+} in this complex is 900 μs which is much higher as compared to 118 μs in aqueous medium, suggesting the luminescence enhancement is a result of reduction in non-radiative decay channels in MeCN medium. Luminescence spectroscopy along with UV–vis spectroscopy is used to study the complexation behavior of Eu{sup 3+}–BA in this medium. In contrary to aqueous medium where Eu{sup 3+}–BA forms ML and ML{sub 2} type species, spectroscopic data reveal formation of only ML{sub 3} complex with composition Eu(BA){sub 3}(MeCN){sub 6} in MeCN medium. Absorbance, luminescence lifetimes and the ratio of areas of 615–592 nm peaks are used in HypSpec computation program to determine the log β for the ML{sub 3} complex. - Highlights: • Luminescence and complexation of Eu{sup 3+}–BA have been studied in MeCN. • The luminescence intensity of Eu{sup 3+}–BA is 320 times more in MeCN compared to aqueous medium. • Luminescence enhancement is a result of sensitization and reduction in non-radiative decay channels in MeCN. • Eu{sup 3+} forms only ML{sub 3} type complex with BA in MeCN contrary to aqueous medium where it forms ML and ML{sub 2} type species.

  11. Investigation of optical and spectroscopic properties of Sm3+ ions in CaBAl glasses

    Science.gov (United States)

    Brito, D. R. N.; Queiroz, M. N.; Barboza, M. J.; Steimacher, A.; Pedrochi, F.

    2017-02-01

    Samples of CaBAl glass with composition of (25-x)CaO-50B2O3-15Al2O3-10CaF2-xSm2O3, with Sm2O3 concentration varying from 0.5 to 7 wt%, were prepared by using melt-quenching method in air atmosphere. The samples were prepared with different concentrations of Sm2O3, aiming to understand how the dopant changes the optical and spectroscopic properties of the glass. The doped CaBAl glasses were studied by means of volumetric density measurements, refractive index, optical absorption, luminescence at room temperature, luminescence as function of the temperature and radiative lifetime. All results were discussed in function of Sm2O3 concentration. The measured volumetric density and polarizability showed an increase with Sm2O3 doping. The refractive index showed a small increase due to RE doping, although within the errors. The absorption bands were attributed to Sm3+ transitions from the ground state 6H5/2 to the various excited states. The luminescence spectra present emission bands assigned to the appropriate electronic f-f transitions of Sm3+ ions; there are four emission bands at 565, 602, 649 and 710 nm. The luminescence quenching was observed up to 2 wt% of Sm2O3. The O/R ratio as function of the Sm2O3 concentration showed changes in the symmetry site with addition of Sm2O3. The CIE 1931 diagram presented a reddish-orange shift color with Sm2O3 doping. The luminescence intensity presents a decrease with temperature increase for all studied samples. The experimental lifetime decreases with the increase of Sm2O3, mainly due to ion-ion interaction.

  12. Computational and Spectroscopic Investigations of the Molecular Scale Structure and Dynamics of Geologically Important Fluids and Mineral-Fluid Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    R. James Kirkpatrick; Andrey G. Kalinichev

    2008-11-25

    significantly larger systems. These calculations have allowed us, for the first time, to study the effects of metal cations with different charges and charge density on the NOM aggregation in aqueous solutions. Other computational work has looked at the longer-time-scale dynamical behavior of aqueous species at mineral-water interfaces investigated simultaneously by NMR spectroscopy. Our experimental NMR studies have focused on understanding the structure and dynamics of water and dissolved species at mineral-water interfaces and in two-dimensional nano-confinement within clay interlayers. Combined NMR and MD study of H2O, Na+, and Cl- interactions with the surface of quartz has direct implications regarding interpretation of sum frequency vibrational spectroscopic experiments for this phase and will be an important reference for future studies. We also used NMR to examine the behavior of K+ and H2O in the interlayer and at the surfaces of the clay minerals hectorite and illite-rich illite-smectite. This the first time K+ dynamics has been characterized spectroscopically in geochemical systems. Preliminary experiments were also performed to evaluate the potential of 75As NMR as a probe of arsenic geochemical behavior. The 75As NMR study used advanced signal enhancement methods, introduced a new data acquisition approach to minimize the time investment in ultra-wide-line NMR experiments, and provides the first evidence of a strong relationship between the chemical shift and structural parameters for this experimentally challenging nucleus. We have also initiated a series of inelastic and quasi-elastic neutron scattering measurements of water dynamics in the interlayers of clays and layered double hydroxides. The objective of these experiments is to probe the correlations of water molecular motions in confined spaces over the scale of times and distances most directly comparable to our MD simulations and on a time scale different than that probed by NMR. This work is being done

  13. Space-time Resolved Spectroscopic System Based on a Rotating Hexahedral Mirror for Measurement of Visible and Ultraviolet Spectral Line Emissions

    Institute of Scientific and Technical Information of China (English)

    Wu Zhenwei; Wan Baonian; Zhou Qian; Huang Juan

    2005-01-01

    By using a rotating hexahedral mirror placed in front of the objective lens and two sets of visible and ultraviolet monochromators coupled with a branchy quartz fiber bundle, a spacetime resolved spectroscopic system has been developed on the HT-7 superconducting tokamak. A center monitoring system has been used including a Helium-Neon laser and a photodiode detector to indicate the absolute position of the measurement in order to reduce the error caused by the uncertain emissive position of the plasma. By using the asymmetric Abel inversion, the spacetime resolved local emission coefficients of the spectroscopic line emissions have been obtained.Presented in this article are simultaneous measurements of two spectral line emissions such as CV ~ 227.1 nm and OV ~ 278.1 nm during a single plasma discharge on the HT-7. Experimental results indicate that the time resolution is better than 3 ms, the space resolution is better than 1.5 cm, the ratio of signal to background is better than 10:1, and the relative error of chord-integrated emission profile is less than 10%. Compared to traditional multichannel detecting systems, this system has considerably improved measurement efficiency, reduced uncertainty, and is therefore suitable for transport studies of global particles and impurities.

  14. Spectroscopic Investigation of the Argon Metastable State Through Optical Emission From Pulsed Argon Discharge

    Science.gov (United States)

    2010-07-01

    within the interstellar medium, but also occurs naturally on earth in our ionosphere, auroras, lightning, and fire. Artificial sources can also...collide with another particle and exchange energy. Some electrons may travel further, and therefore increase their energy, before a collision takes place...line shape was unaffected by greater filtering, which indicated the absence of power broadening due to saturation. From the filters, the beam traveled

  15. Investigation of temperature dependent dielectric constant of a sputtered TiN thin film by spectroscopic ellipsometry

    Science.gov (United States)

    Tripura Sundari, S.; Ramaseshan, R.; Jose, Feby; Dash, S.; Tyagi, A. K.

    2014-01-01

    The temperature dependence of optical constants of titanium nitride thin film is investigated using Spectroscopic Ellipsometry (SE) between 1.4 and 5 eV in the temperature range of 300 K to 650 K in steps of 50 K. The real and imaginary parts of the dielectric functions ɛ1(E) and ɛ2(E) marginally increase with increase in temperature. A Drude Lorentz dielectric analysis based on free electron and oscillator model are carried out to describe the temperature behavior. With increase in temperature, the unscreened plasma frequency and broadening marginally decreased and increased, respectively. The parameters of the Lorentz oscillator model also showed that the relaxation time decreased with temperature while the oscillator energies increased. This study shows that owing to the marginal change in the refractive index with temperature, titanium nitride can be employed for surface plasmon sensor applications even in environments where rise in temperature is imminent.

  16. Probing the Physics of Narrow-line Regions in Active Galaxies. IV. Full Data Release of the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7)

    Science.gov (United States)

    Thomas, Adam D.; Dopita, Michael A.; Shastri, Prajval; Davies, Rebecca; Hampton, Elise; Kewley, Lisa; Banfield, Julie; Groves, Brent; James, Bethan L.; Jin, Chichuan; Juneau, Stéphanie; Kharb, Preeti; Sairam, Lalitha; Scharwächter, Julia; Shalima, P.; Sundar, M. N.; Sutherland, Ralph; Zaw, Ingyin

    2017-09-01

    We present the second and final data release of the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7). Data are presented for 63 new galaxies not included in the first data release, and we provide 2D emission-line fitting products for the full S7 sample of 131 galaxies. The S7 uses the WiFeS instrument on the ANU 2.3 m telescope to obtain spectra with a spectral resolution of R = 7000 in the red (540–700 nm) and R = 3000 in the blue (350–570 nm), over an integral field of 25 × 38 arcsec2 with 1 × 1 arcsec2 spatial pixels. The S7 contains both the largest sample of active galaxies and the highest spectral resolution of any comparable integral field survey to date. The emission-line fitting products include line fluxes, velocities, and velocity dispersions across the WiFeS field of view, and an artificial neural network has been used to determine the optimal number of Gaussian kinematic components for emission-lines in each spaxel. Broad Balmer lines are subtracted from the spectra of nuclear spatial pixels in Seyfert 1 galaxies before fitting the narrow lines. We bin nuclear spectra and measure reddening-corrected nuclear fluxes of strong narrow lines for each galaxy. The nuclear spectra are classified on optical diagnostic diagrams, where the strength of the coronal line [Fe vii] λ6087 is shown to be correlated with [O iii]/Hβ. Maps revealing gas excitation and kinematics are included for the entire sample, and we provide notes on the newly observed objects.

  17. 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.

  18. Sm{sup 3+}-doped Sc{sub 2}O{sub 3} polycrystalline ceramics: Spectroscopic investigation

    Energy Technology Data Exchange (ETDEWEB)

    Gheorghe, Cristina, E-mail: cristina_gheorghe2002@yahoo.com [National Institute for Laser, Plasma and Radiation Physics, ECS Laboratory, 077125 Magurele-Bucharest (Romania); Lupei, Aurelia; Voicu, Flavius [National Institute for Laser, Plasma and Radiation Physics, ECS Laboratory, 077125 Magurele-Bucharest (Romania); Enculescu, Monica [National Institute of Materials Physics Optics and Spectroscopy Laboratory, PO Box MG-7, 77125 Magurele-Bucharest (Romania)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Investigation of Sm{sup 3+}: Sc{sub 2}O{sub 3} ceramics in order to evaluate its potential for visible emission. Black-Right-Pointing-Pointer The optical spectra in the UV-IR at 10 and 300 K range of Sm{sup 3+} Sc{sub 2}O{sub 3} ceramics, were performed. Black-Right-Pointing-Pointer Spectroscopic parameters were evaluated in the frame of the Judd-Ofelt theory. - Abstract: Sm{sup 3+}-doped Sc{sub 2}O{sub 3} translucent polycrystalline ceramics were fabricated by solid-state reaction method in order to evaluate its potential for visible emission. The optical spectra in the UV-IR range of Sm{sup 3+} in these samples, at different temperatures (10-300 K), were performed. A series of data on Sm: Sc{sub 2}O{sub 3} system not investigated previously were obtained from the analysis of the absorption and visible emission spectra as well as the emission kinetics: an extended energy level scheme, absorption cross sections for different bands, lifetimes, etc. Additional spectroscopic parameters were evaluated in the frame of the Judd-Ofelt (J-O) theory: J-O intensity parameters, oscillator strengths, radiative transitions probabilities, radiative lifetimes, branching ratios, and the cross sections (by Fuechtbauer-Ladenburg) of the main three visible emissions: {sup 4}G{sub 5/2} {yields} {sup 6}H{sub 5/2} (yellow), {sup 4}G{sub 5/2} {yields} {sup 6}H{sub 7/2} (orange) and {sup 4}G{sub 5/2} {yields} {sup 6}H{sub 9/2} (red).

  19. Study of the spray to globular transition in gas metal arc welding: a spectroscopic investigation

    Science.gov (United States)

    Valensi, F.; Pellerin, S.; Castillon, Q.; Boutaghane, A.; Dzierzega, K.; Zielinska, S.; Pellerin, N.; Briand, F.

    2013-06-01

    The gas metal arc welding (GMAW) process is strongly influenced by the composition of the shielding gas. In particular, addition of CO2 increases the threshold current for the transition from unstable globular to more stable spray transfer mode. We report on the diagnostics—using optical emission spectroscopy—of a GMAW plasma in pure argon and in mixtures of argon, CO2 and N2 while operated in spray and globular transfer modes. The spatially resolved plasma parameters are obtained by applying the Abel transformation to laterally integrated emission data. The Stark widths of some iron lines are used to determine both electron density and temperature, and line intensities yield relative contents of neutral and ionized iron to argon. Our experimental results indicate a temperature drop on the arc axis in the case of spray arc transfer. This drop reduces with addition of N2 and disappears in globular transfer mode when CO2 is added. Despite the temperature increase, the electron density decreases with CO2 concentration. The highest concentration of iron is observed in the plasma column upper part (close to the anode) and for GMAW with CO2. Our results are compared with recently published works where the effect of non-homogeneous metal vapour concentration has been taken into account.

  20. VERY STRONG EMISSION-LINE GALAXIES IN THE WFC3 INFRARED SPECTROSCOPIC PARALLEL SURVEY AND IMPLICATIONS FOR HIGH-REDSHIFT GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Atek, H.; Colbert, J.; Shim, H. [Spitzer Science Center, Caltech, Pasadena, CA 91125 (United States); Siana, B.; Bridge, C. [Department of Astronomy, Caltech, Pasadena, CA 91125 (United States); Scarlata, C. [Department of Astronomy, University of Minnesota-Twin Cities, Minneapolis, MN 55455 (United States); Malkan, M.; Ross, N. R. [Department of Physics and Astronomy, University of California, Los Angeles, CA (United States); McCarthy, P.; Dressler, A.; Hathi, N. P. [Observatories of the Carnegie Institution for Science, Pasadena, CA 91101 (United States); Teplitz, H. [Infrared Processing and Analysis Center, Caltech, Pasadena, CA 91125 (United States); Henry, A.; Martin, C. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Bunker, A. J. [Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Fosbury, R. A. E. [Space Telescope-European Coordinating Facility, Garching bei Muenchen (Germany)

    2011-12-20

    The WFC3 Infrared Spectroscopic Parallel Survey uses the Hubble Space Telescope (HST) infrared grism capabilities to obtain slitless spectra of thousands of galaxies over a wide redshift range including the peak of star formation history of the universe. We select a population of very strong emission-line galaxies with rest-frame equivalent widths (EWs) higher than 200 A. A total of 176 objects are found over the redshift range 0.35 < z < 2.3 in the 180 arcmin{sup 2} area that we have analyzed so far. This population consists of young and low-mass starbursts with high specific star formation rates (sSFR). After spectroscopic follow-up of one of these galaxies with Keck/Low Resolution Imaging Spectrometer, we report the detection at z = 0.7 of an extremely metal-poor galaxy with 12 + log(O/H) =7.47 {+-} 0.11. After estimating the active galactic nucleus fraction in the sample, we show that the high-EW galaxies have higher sSFR than normal star-forming galaxies at any redshift. We find that the nebular emission lines can substantially affect the total broadband flux density with a median brightening of 0.3 mag, with some examples of line contamination producing brightening of up to 1 mag. We show that the presence of strong emission lines in low-z galaxies can mimic the color-selection criteria used in the z {approx} 8 dropout surveys. In order to effectively remove low-redshift interlopers, deep optical imaging is needed, at least 1 mag deeper than the bands in which the objects are detected. Without deep optical data, most of the interlopers cannot be ruled out in the wide shallow HST imaging surveys. Finally, we empirically demonstrate that strong nebular lines can lead to an overestimation of the mass and the age of galaxies derived from fitting of their spectral energy distribution (SED). Without removing emission lines, the age and the stellar mass estimates are overestimated by a factor of 2 on average and up to a factor of 10 for the high-EW galaxies

  1. Solid-State Spectroscopic Investigation of Molecular Interactions between Clofazimine and Hypromellose Phthalate in Amorphous Solid Dispersions.

    Science.gov (United States)

    Nie, Haichen; Su, Yongchao; Zhang, Mingtao; Song, Yang; Leone, Anthony; Taylor, Lynne S; Marsac, Patrick J; Li, Tonglei; Byrn, Stephen R

    2016-11-07

    It has been technically challenging to specify the detailed molecular interactions and binding motif between drugs and polymeric inhibitors in the solid state. To further investigate drug-polymer interactions from a molecular perspective, a solid dispersion of clofazimine (CLF) and hypromellose phthalate (HPMCP), with reported superior amorphous drug loading capacity and physical stability, was selected as a model system. The CLF-HPMCP interactions in solid dispersions were investigated by various solid state spectroscopic methods including ultraviolet-visible (UV-vis), infrared (IR), and solid-state NMR (ssNMR) spectroscopy. Significant spectral changes suggest that protonated CLF is ionically bonded to the carboxylate from the phthalyl substituents of HPMCP. In addition, multivariate analysis of spectra was applied to optimize the concentration of polymeric inhibitor used to formulate the amorphous solid dispersions. Most interestingly, proton transfer between CLF and carboxylic acid was experimentally investigated from 2D (1)H-(1)H homonuclear double quantum NMR spectra by utilizing the ultrafast magic-angle spinning (MAS) technique. The molecular interaction pattern and the critical bonding structure in CLF-HPMCP dispersions were further delineated by successfully correlating ssNMR findings with quantum chemistry calculations. These high-resolution investigations provide critical structural information on active pharmaceutical ingredient-polymer interaction, which can be useful for rational selection of appropriate polymeric carriers, which are effective crystallization inhibitors for amorphous drugs.

  2. A spectroscopic survey of Herbig Ae/Be stars with X-Shooter - II. Accretion diagnostic lines

    Science.gov (United States)

    Fairlamb, J. R.; Oudmaijer, R. D.; Mendigutia, I.; Ilee, J. D.; van den Ancker, M. E.

    2017-02-01

    The Herbig Ae/Be stars (HAeBes) allow an exploration of the properties of pre-main-sequence(PMS) stars above the low-mass range (8 M_{⊙}). This paper is the second in a series exploring accretion in 91 HAeBes with Very Large Telescope/X-shooter spectra. Equivalent width measurements are carried out on 32 different lines, spanning the UV (ultraviolet) to NIR (near infrared), in order to obtain their line luminosities. The line luminosities were compared to accretion luminosities that were determined directly from measurements of a UV excess. When detected, emission lines always demonstrate a correlation with the accretion luminosity, regardless of detection frequency. The average relationship between accretion luminosity and line luminosity is found to be L_acc ∝ L_line1.16 ± 0.15. This is in agreement with the findings in Classical T Tauri stars, although the HAeBe relationship is generally steeper, particularly towards the Herbig Be mass range. Since all observed lines display a correlation with the accretion luminosity, all of them can be used as accretion tracers. This has increased the number of accretion diagnostic lines in HAeBes 10-fold. However, questions still remain on the physical origin of each line, which may not be due to accretion.

  3. An eclipsing double-line spectroscopic binary at the stellar/substellar boundary in the Upper Scorpius OB association

    CERN Document Server

    Lodieu, N; Hernandez, J I Gonzalez; Sanchis-Ojeda, R; Narita, N; Kawashima, Y; Kawauchi, K; Mascareño, A Suarez; Deeg, H; Arranz, J Prieto; Rebolo, R; Palle, E; Bejar, V J S; Ferragamo, A; Rubiño-Martin, J A

    2015-01-01

    We aim at constraining evolutionary models at low mass and young ages by identifying interesting transiting system members of the nearest OB association to the Sun, Upper Scorpius, targeted by the Kepler mission. We produced light curves for M dwarf members of the USco region surveyed during the second campaign of the Kepler K2 mission. We identified 'by eye' a transiting system, UScoJ161630.68-251220.1 (=EPIC203710387) with a combined spectral type of M5.25 whose photometric, astrometric, and spectroscopic properties makes it a member of USco. We conducted an extensive photometric and spectroscopic follow-up of this transiting system with a suite of telescopes and instruments to characterise the properties of each component of the system. We calculated a transit duration of about 2.42 hours occuring every 2.88 days with a slight difference in transit depth and phase between the two components. We estimated a mass ratio of 0.922+/-0.015 from the semi-amplitudes of the radial velocity curves for each component...

  4. Phylogenomic investigation of CR1 LINE diversity in reptiles.

    Science.gov (United States)

    Shedlock, Andrew M

    2006-12-01

    It is unlikely that taxonomically diverse phylogenetic studies will be completed rapidly in the near future for nonmodel organisms on a whole-genome basis. However, one approach to advancing the field of "phylogenomics" is to estimate the structure of poorly known genomes by mining libraries of clones from suites of taxa, rather than from single species. The present analysis adopts this approach by taking advantage of megabase-scale end-sequence scanning of reptilian genomic clones to characterize diversity of CR1-like LINEs, the dominant family of transposable elements (TEs) in the sister group of mammals. As such, it helps close an important gap in the literature on the molecular systematics and evolution of retroelements in nonavian reptiles. Results from aligning more than 14 Mb of sequence from the American alligator (Alligator mississippiensis), painted turtle (Chrysemys picta), Bahamian green anole (Anolis smaragdinus), Tuatara (Sphenodon punctatus), Emu (Dromaius novaehollandiae), and Zebra Finch (Taeniopygia guttata) against a comprehensive library approximately 3000 TE-encoding peptides reflect an increasing abundance of LINE and non-long-terminal-repeat (non-LTR) retrotransposon repeat types with the age of common ancestry among exemplar reptilian clades. The hypothesis that repeat diversity is correlated with basal metabolic rate was tested using comparative methods and a significant nonlinear relationship was indicated. This analysis suggests that the age of divergence between an exemplary clade and its sister group as well as metabolic correlates should be considered in addition to genome size in explaining patterns of retroelement diversity. The first phylogenetic analysis of the largely unexplored chicken repeat 1 (CR1) 3' reverse transcriptase (RT) conserved domains 8 and 9 in nonavian reptiles reveals a pattern of multiple lineages with variable branch lengths, suggesting presence of both old and young elements and the existence of several

  5. NIR fluorescence spectroscopic investigations of Er{sup 3+}-ions doped borate based tellurium calcium zinc niobium oxide glasses

    Energy Technology Data Exchange (ETDEWEB)

    Ravi, O. [Department of Instrumentation, Sri Venkateswara University, Tirupati 517502 (India); Dhoble, S.J. [Department of Physics, RTM Nagpur University, Nagpur 440033 (India); Ramesh, B.; Devarajulu, G. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Reddy, C. Madhukar [Department of Physics, AP Model School, Yerravaripalem 517194 (India); Linganna, K. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Reddy, G. Rajasekhar [Department of Instrumentation, Sri Venkateswara University, Tirupati 517502 (India); Raju, B. Deva Prasad, E-mail: drdevaprasadraju@gmail.com [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Department of Future Studies, Sri Venkateswara University, Tirupati 517502 (India)

    2015-08-15

    A series of Er{sup 3+} ions doped tellurium calcium zinc niobium borate glasses were prepared by the melt quenching technique. The prepared samples were investigated by optical absorption and near infrared fluorescence spectroscopic studies. The obtained Judd–Ofelt intensity parameters Ω{sub λ} (λ=2, 4 and 6) were determined through experimental and calculated oscillator strengths obtained from absorption spectra and their results are studied and compared with reported literature. The stark-level energies of {sup 4}I{sub 13/2} excited and {sup 4}I{sub 15/2} ground states were evaluated by using both the absorption and emission measurements. The effect of Er{sup 3+} ion concentration on the emission intensity of {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} transition was discussed. Intense and broad 1.53 µm infrared fluorescence is observed at 980 nm diode laser excitation. Photoluminescence (PL) and its decay behavior studies were carried out for the transition {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} at 1.53 µm emission. The broad emission together with higher values of the bandwidth (81 nm), stimulated emission cross-section (32.25×10{sup −22} cm{sup 2}) and lifetime (530 µs for 1.0 mol% of Er{sup 3+}) of level {sup 4}I{sub 13/2} make these glasses attractive for broadband amplifiers. From the analysis of spectroscopic data, the present glass is a prospective photonic material for practical applications in the visible and NIR region. - Highlights: • In this study we prepared TCZNB glasses doped with Er{sup 3+} ions. • Glasses are characterized with absorption, emission and lifetime analysis. • Judd–Ofelt theory is used to calculate radiative properties. • TCZNB glasses could be used as NIR lasers.

  6. Investigation of a stripline transmission line structure for gyromagnetic nonlinear transmission line high power microwave sources.

    Science.gov (United States)

    Reale, D V; Parson, J M; Neuber, A A; Dickens, J C; Mankowski, J J

    2016-03-01

    A stripline gyromagnetic nonlinear transmission line (NLTL) was constructed out of yttrium iron garnet ferrite and tested at charge voltages of 35 kV-55 kV with bias fields ranging from 10 kA/m to 20 kA/m. Typically, high power gyromagnetic NLTLs are constructed in a coaxial geometry. While this approach has many advantages, including a uniform transverse electromagnetic (TEM) mode, simple interconnection between components, and the ability to use oil or pressurized gas as an insulator, the coaxial implementation suffers from complexity of construction, especially when using a solid insulator. By moving to a simpler transmission line geometry, NLTLs can be constructed more easily and arrayed on a single substrate. This work represents a first step in exploring the suitability of various transmission line structures, such as microstrips and coplanar waveguides. The resulting high power microwave (HPM) source operates in ultra high frequency (UHF) band with an average bandwidth of 40.1% and peak rf power from 2 MW to 12.7 MW.

  7. Spectroscopic investigation on the interaction of copper porphyrazines and phthalocyanine with human telomeric G-quadruplex DNA.

    Science.gov (United States)

    Hassani, Leila; Hakimian, Fatemeh; Safaei, Elham

    2014-01-01

    The G-quadruplex DNA is a novel target for anticancer drug discovery and many scientific groups are investigating interaction of small molecules with G-quadruplex DNA to discover therapeutic agents for cancer. Here, interaction of a phthalocyanine (Cu(PcTs)) and two tetrapyridinoporphyrazines ([Cu(2,3-tmtppa)](4+) and [Cu(3,4-tmtppa)](4+)) with Na(+) and K(+) forms of human telomeric G-quadruplex DNA has been investigated by spectroscopic techniques. The results indicated that interaction of the cationic porphyrazines is remarkably stronger than the anionic phthalocyanine and they presumably bind to the G-quadruplex DNA through end-stacking. Fluorescent intercalator displacement assay implied the displacement ability of the complexes with thiazole orange. In addition, circular dichroism spectra of both quadruplex forms converge to the Na(+) isoform after binding to the porphyrazines. In conclusion, the porphyrazines as the complexes that bind to the G-quadruplex DNA, could be suitable candidates for further investigations about inhibition of telomerase enzyme. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Technical and technological investigation of cultural heritage: experience in applications of spectroscopic methods

    Science.gov (United States)

    Grigorieva, I. A.; Chugunova, K. S.; Kadikova, I. F.; Khavrin, S. V.; Pisareva, S. A.

    2016-12-01

    Physical and chemical methods of analysis are indispensable for restoration, study of painting techniques, examination and attribution of works of art. Development of new directions of investigations as well as improvements in sample preparation allow applying non-destructive analysis methods, minimizing amount of matter used to obtain informative spectra, preventing alteration and destruction of samples in the course of investigation. This paper observes the examples of applying optical and spectral methods, including molecular spectral analysis and electron microscopy, for study of binding media and pigments of painting and archaeological artifacts.

  9. Technical and technological investigation of cultural heritage: experience in applications of spectroscopic methods

    Directory of Open Access Journals (Sweden)

    Grigorieva I.A.

    2017-01-01

    Full Text Available Physical and chemical methods of analysis are indispensable for restoration, study of painting techniques, examination and attribution of works of art. Development of new directions of investigations as well as improvements in sample preparation allow applying non-destructive analysis methods, minimizing amount of matter used to obtain informative spectra, preventing alteration and destruction of samples in the course of investigation. This paper observes the examples of applying optical and spectral methods, including molecular spectral analysis and electron microscopy, for study of binding media and pigments of painting and archaeological artifacts.

  10. Spectroscopic investigations, antimicrobial, and cytotoxic activity of green synthesized gold nanoparticles

    Science.gov (United States)

    Lokina, S.; Suresh, R.; Giribabu, K.; Stephen, A.; Lakshmi Sundaram, R.; Narayanan, V.

    2014-08-01

    The gold nanoparticles (AuNPs) were synthesized by using naturally available Punica Granatum fruit extract as reducing and stabilizing agent. The biosynthesized AuNPs was characterized by using UV-Vis, fluorescence, high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and thermogravimetric (TGA) analysis. The surface plasmon resonance (SPR) band at 585 nm confirmed the reduction of auric chloride to AuNPs. The crystalline nature of the biosynthesized AuNPs was confirmed from the HRTEM images, XRD and selected area electron diffraction (SAED) pattern. The HRTEM images showed the mixture of triangular and spherical-like AuNPs having size between 5 and 20 nm. The weight loss of the AuNPs was measured by TGA as a function of temperature under a controlled atmosphere. The biomolecules are responsible for the reduction of AuCl4- ions and the formation of stable AuNPs which was confirmed by FTIR measurement. The synthesized AuNPs showed an excellent antibacterial activity against Candida albicans (ATCC 90028), Aspergillus flavus (ATCC 10124), Staphylococcus aureus (ATCC 25175), Salmonella typhi (ATCC 14028) and Vibrio cholerae (ATCC 14033). The minimum inhibitory concentration (MIC) of AuNPs was recorded against various microorganisms. Further, the synthesized AuNPs shows an excellent cytotoxic result against HeLa cancer cell lines at different concentrations.

  11. 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.

  12. Spectroscopic investigations, antimicrobial, and cytotoxic activity of green synthesized gold nanoparticles.

    Science.gov (United States)

    Lokina, S; Suresh, R; Giribabu, K; Stephen, A; Lakshmi Sundaram, R; Narayanan, V

    2014-08-14

    The gold nanoparticles (AuNPs) were synthesized by using naturally available Punica Granatum fruit extract as reducing and stabilizing agent. The biosynthesized AuNPs was characterized by using UV-Vis, fluorescence, high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and thermogravimetric (TGA) analysis. The surface plasmon resonance (SPR) band at 585nm confirmed the reduction of auric chloride to AuNPs. The crystalline nature of the biosynthesized AuNPs was confirmed from the HRTEM images, XRD and selected area electron diffraction (SAED) pattern. The HRTEM images showed the mixture of triangular and spherical-like AuNPs having size between 5 and 20nm. The weight loss of the AuNPs was measured by TGA as a function of temperature under a controlled atmosphere. The biomolecules are responsible for the reduction of AuCl4(-) ions and the formation of stable AuNPs which was confirmed by FTIR measurement. The synthesized AuNPs showed an excellent antibacterial activity against Candida albicans (ATCC 90028), Aspergillus flavus (ATCC 10124), Staphylococcus aureus (ATCC 25175), Salmonella typhi (ATCC 14028) and Vibrio cholerae (ATCC 14033). The minimum inhibitory concentration (MIC) of AuNPs was recorded against various microorganisms. Further, the synthesized AuNPs shows an excellent cytotoxic result against HeLa cancer cell lines at different concentrations.

  13. Emission Spectroscopic Boundary Layer Investigation during Ablative Material Testing in Plasmatron.

    Science.gov (United States)

    Helber, Bernd; Chazot, Olivier; Hubin, Annick; Magin, Thierry E

    2016-06-09

    Ablative Thermal Protection Systems (TPS) allowed the first humans to safely return to Earth from the moon and are still considered as the only solution for future high-speed reentry missions. But despite the advancements made since Apollo, heat flux prediction remains an imperfect science and engineers resort to safety factors to determine the TPS thickness. This goes at the expense of embarked payload, hampering, for example, sample return missions. Ground testing in plasma wind-tunnels is currently the only affordable possibility for both material qualification and validation of material response codes. The subsonic 1.2MW Inductively Coupled Plasmatron facility at the von Karman Institute for Fluid Dynamics is able to reproduce a wide range of reentry environments. This protocol describes a procedure for the study of the gas/surface interaction on ablative materials in high enthalpy flows and presents sample results of a non-pyrolyzing, ablating carbon fiber precursor. With this publication, the authors envisage the definition of a standard procedure, facilitating comparison with other laboratories and contributing to ongoing efforts to improve heat shield reliability and reduce design uncertainties. The described core techniques are non-intrusive methods to track the material recession with a high-speed camera along with the chemistry in the reactive boundary layer, probed by emission spectroscopy. Although optical emission spectroscopy is limited to line-of-sight measurements and is further constrained to electronically excited atoms and molecules, its simplicity and broad applicability still make it the technique of choice for analysis of the reactive boundary layer. Recession of the ablating sample further requires that the distance of the measurement location with respect to the surface is known at all times during the experiment. Calibration of the optical system of the applied three spectrometers allowed quantitative comparison. At the fiber scale

  14. Emission Spectroscopic Boundary Layer Investigation during Ablative Material Testing in Plasmatron

    Science.gov (United States)

    Helber, Bernd; Chazot, Olivier; Hubin, Annick; Magin, Thierry E.

    2016-01-01

    Ablative Thermal Protection Systems (TPS) allowed the first humans to safely return to Earth from the moon and are still considered as the only solution for future high-speed reentry missions. But despite the advancements made since Apollo, heat flux prediction remains an imperfect science and engineers resort to safety factors to determine the TPS thickness. This goes at the expense of embarked payload, hampering, for example, sample return missions. Ground testing in plasma wind-tunnels is currently the only affordable possibility for both material qualification and validation of material response codes. The subsonic 1.2MW Inductively Coupled Plasmatron facility at the von Karman Institute for Fluid Dynamics is able to reproduce a wide range of reentry environments. This protocol describes a procedure for the study of the gas/surface interaction on ablative materials in high enthalpy flows and presents sample results of a non-pyrolyzing, ablating carbon fiber precursor. With this publication, the authors envisage the definition of a standard procedure, facilitating comparison with other laboratories and contributing to ongoing efforts to improve heat shield reliability and reduce design uncertainties. The described core techniques are non-intrusive methods to track the material recession with a high-speed camera along with the chemistry in the reactive boundary layer, probed by emission spectroscopy. Although optical emission spectroscopy is limited to line-of-sight measurements and is further constrained to electronically excited atoms and molecules, its simplicity and broad applicability still make it the technique of choice for analysis of the reactive boundary layer. Recession of the ablating sample further requires that the distance of the measurement location with respect to the surface is known at all times during the experiment. Calibration of the optical system of the applied three spectrometers allowed quantitative comparison. At the fiber scale

  15. Spectroscopic investigation of the constituent components effect on the biodegradable package characteristics

    Science.gov (United States)

    Coťa, C.; Cioica, N.; Filip, C.; Fechete, R.; Todica, M.; Nagy, E. M.; Cozar, O.

    2015-12-01

    The effect of the nature and the content of the plasticizers (water, glycerol) on the corn starch based biodegradable packages properties (crystalline-amorphous) and also on their degradation process after absorption of distilled water were investigated by 1H NMR relaxation and 13C CP/MAS NMR spectroscopies. For this goal, a set of 14 samples with various starch/glycerol/water (mass %) ratios were prepared and investigated after extrusion process in order to establish their crystalline or amorphous character. The composition having starch/glycerol/water 68/17/15 mass % ratio was found to have a dominant amorphous character and very similar features with a commercial specimen (USA) used for the package. It was also found that this best package is extremely degraded after just one day under water absorption. The most resistant package was that with a large content of starch (78/19.5/2.5).

  16. Spectroscopic investigation of the constituent components effect on the biodegradable package characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Coţa, C.; Cioica, N., E-mail: cioica@inma.ro; Nagy, E. M. [National Institute of Research-Development for Machines and Installations Designed to Agriculture and Food Industry – INMA Bucureşti – Cluj-Napoca Branch, 59, Al. Vaida-Voievod Str., RO-400458 Cluj-Napoca (Romania); Filip, C. [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Str., 400293 Cluj-Napoca (Romania); Fechete, R. [Technical University of Cluj-Napoca, Dept. of Physics, 25 G. Baritiu Str., RO-400020 Cluj-Napoca (Romania); Todica, M. [Babeş-Bolyai University, Faculty of Physics, 1 Kogalniceanu Str., RO-400084, Cluj-Napoca (Romania); Cozar, O. [National Institute of Research-Development for Machines and Installations Designed to Agriculture and Food Industry – INMA Bucureşti – Cluj-Napoca Branch, 59, Al. Vaida-Voievod Str., RO-400458 Cluj-Napoca (Romania); Academy of Romanian Scientists, 54 Splaiul Independentei, RO-050094, Bucharest (Romania)

    2015-12-23

    The effect of the nature and the content of the plasticizers (water, glycerol) on the corn starch based biodegradable packages properties (crystalline-amorphous) and also on their degradation process after absorption of distilled water were investigated by {sup 1}H NMR relaxation and {sup 13}C CP/MAS NMR spectroscopies. For this goal, a set of 14 samples with various starch/glycerol/water (mass %) ratios were prepared and investigated after extrusion process in order to establish their crystalline or amorphous character. The composition having starch/glycerol/water 68/17/15 mass % ratio was found to have a dominant amorphous character and very similar features with a commercial specimen (USA) used for the package. It was also found that this best package is extremely degraded after just one day under water absorption. The most resistant package was that with a large content of starch (78/19.5/2.5)

  17. Spectroscopic investigation on the inclusion complex formation between amisulpride and γ-cyclodextrin.

    Science.gov (United States)

    Negi, Jeetendra Singh; Singh, Shivpal

    2013-02-15

    The purpose of this research was to investigate inclusion complex formation between poorly soluble drug amisulpride (AMI) and γ-cyclodextrin (γ-CD). The solubility of AMI was enhanced by formation of inclusion complex of AMI with nano-hydrophobic cavity of γ-CD. The stoichiometry of inclusion complex was studied by continuous variation Job's plot method and found 1:1. The binding constant was found 1166.65 M(-1) by Benesi-Hildebrand plot. The molecular docking of AMI and γ-CD was done to investigate complexation. The inclusion complex formation was further confirmed by (1)H NMR and FT-IR, DSC and XRD analysis. The solubility of AMI was increased 3.74 times after inclusion complex formation with γ-CD.

  18. Matrix Infrared Spectroscopic and Computational Investigations of Novel Small Uranium Containing Molecules - Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, Lester

    2014-10-17

    Direct reactions of f-element uranium, thorium and lanthanide metal atoms were investigated with small molecules. These metal atoms were generated by laser ablation and mixed with the reagent molecules then condensed with noble gases at 4K. The products were analyzed by absorption of infrared light to measure vibrational frequencies which were confirmed by quantum chemical calculations. We have learned more about the reactivity of uranium atoms with common molecules, which will aid in the develolpment of further applications of uranium.

  19. Spectroscopic Investigation of Indium Halides as Substitutes of Mercury in Low Pressure Discharges for Lighting Applications

    OpenAIRE

    Briefi, Stefan

    2012-01-01

    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 dissociatio...

  20. Investigation Of In-Line Monitoring Options At H Canyon/HB Line For Plutonium Oxide Production

    Energy Technology Data Exchange (ETDEWEB)

    Sexton, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-14

    H Canyon and HB Line have a production goal of 1 MT per year of plutonium oxide feedstock for the MOX facility by FY17 (AFS-2 mission). In order to meet this goal, steps will need to be taken to improve processing efficiency. One concept for achieving this goal is to implement in-line process monitoring at key measurement points within the facilities. In-line monitoring during operations has the potential to increase throughput and efficiency while reducing costs associated with laboratory sample analysis. In the work reported here, we mapped the plutonium oxide process, identified key measurement points, investigated alternate technologies that could be used for in-line analysis, and initiated a throughput benefit analysis.

  1. In situ vibrational spectroscopic investigation of C4 hydrocarbon selective oxidation over vanadium-phosphorus-oxide catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Zhi -Yang [Iowa State Univ., Ames, IA (United States)

    1999-05-10

    n-Butane selective oxidation over the VPO catalyst to maleic anhydride is the first and only commercialized process of light alkane selective oxidation. The mechanism of this reaction is still not well known despite over twenty years of extensive studies, which can partially be attributed to the extreme difficulties to characterize catalytic reactions real-time under typical reaction conditions. In situ spectroscopic characterization techniques such as Infrared spectroscopy and laser Raman spectroscopy were used in the current mechanistic investigations of n-butane oxidation over VPO catalysts. To identify the reaction intermediates, oxidation of n-butane, 1,3-butadiene and related oxygenates on the VPO catalyst were monitored using FTIR spectroscopy under transient conditions. n-Butane was found to adsorb on the VPO catalyst to form olefinic species, which were further oxidized to unsaturated, noncyclic carbonyl species. The open chain dicarbonyl species then experienced cycloaddition to form maleic anhydride. VPO catalyst phase transformations were investigated using in situ laser Raman spectroscopy. This report contains Chapter 1: General introduction; Chapter 2: Literature review; and Chapter 5: Conclusion and recommendations.

  2. Investigation on the interaction between isorhamnetin and bovine liver catalase by spectroscopic techniques under different pH conditions.

    Science.gov (United States)

    Yang, Yumin; Li, Daojin

    2016-08-01

    The binding of isorhamnetin to bovine liver catalase (BLC) was first investigated at 302, 310 and 318 K at pH 7.4 using spectroscopic methods including fluorescence spectra, circular dichroism (CD) and UV-vis absorption. Spectrophotometric observations are rationalized mainly in terms of a static quenching process. The binding constants and binding sites were evaluated by fluorescence quenching methods. Enzymatic activity of BLC in the absence and presence of isorhamnetin was measured using a UV/vis spectrophotometer. The result revealed that the binding of isorhamnetin to BLC led to a reduction in the activity of BLC. The positive entropy change and enthalpy change indicated that the interaction of isorhamnetin with BLC was mainly driven by hydrophobic forces. The distance r between the donor (BLC) and acceptor (isorhamnetin) was estimated to be 2.99 nm according to fluorescence resonance energy transfer. Fluorescence, synchronous fluorescence, and CD spectra showed no obvious change in the conformation of BLC upon the binding of isorhamnetin. In addition, the influence of pH on the binding of isorhamnetin to BLC was investigated and the binding ability of the drug to BLC deceased under other pH conditions (pH 9.0, 6.5, 5.0, 3.5, or 2.0) as compared with that at pH 7.4. Copyright © 2016 John Wiley & Sons, Ltd.

  3. In situ vibrational spectroscopic investigation of C{sub 4} hydrocarbon selective oxidation over vanadium-phosphorus-oxide catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Z.Y.

    1999-05-10

    n-Butane selective oxidation over the VPO catalyst to maleic anhydride is the first and only commercialized process of light alkane selective oxidation. The mechanism of this reaction is still not well known despite over twenty years of extensive studies, which can partially be attributed to the extreme difficulties to characterize catalytic reactions real-time under typical reaction conditions. In situ spectroscopic characterization techniques such as Infrared spectroscopy and laser Raman spectroscopy were used in the current mechanistic investigations of n-butane oxidation over VPO catalysts. To identify the reaction intermediates, oxidation of n-butane, 1,3-butadiene and related oxygenates on the VPO catalyst were monitored using FTIR spectroscopy under transient conditions. n-Butane was found to adsorb on the VPO catalyst to form olefinic species, which were further oxidized to unsaturated, noncyclic carbonyl species. The open chain dicarbonyl species then experienced cycloaddition to form maleic anhydride. VPO catalyst phase transformations were investigated using in situ laser Raman spectroscopy. This report contains Chapter 1: General introduction; Chapter 2: Literature review; and Chapter 5: Conclusion and recommendations.

  4. Spectroscopic, DFT and Z-scan supported investigation of dicyanoisophorone based push-pull NLOphoric styryl dyes

    Science.gov (United States)

    Erande, Yogesh; Sreenath, Mavila C.; Chitrambalam, Subramaniyan; Joe, Isaac H.; Sekar, Nagaiyan

    2017-04-01

    The dicyanoisophorone acceptor based NLOphores with Intramolecular Charge Transfer (ICT) character are newly synthesised, characterised and explored for linear and non linear optical (NLO) property investigation. Strong ICT character of these D-π-A styryl NLOphores is established with support of emission solvatochromism, polarity functions and Generalised Mulliken Hush (GMH) analysis. First, second and third order polarizability of these NLOphores is investigated by spectroscopic and TDDFT computational approach using CAM/B3LYP-6-311 + g (d, p) method. BLA and BOA values of these chromophores are evaluated from ground and excited state optimized geometries and found that the respective structures are approaching towards cyanine limit. Third order nonlinear susceptibility (X(3)/SUP>) along with nonlinear absorption coefficient (β) and nonlinear refraction (n2) are evaluated for these NLOphores using Z-scan experiment. All four chromophores exhibit large polarization anisotropy (Δα), first order hyperpolarizability (β0), second order hyperpolarizability (γ) and third order nonlinear susceptibility (X(3)/SUP>). TGA analysis proved these NLOphores are stable up to 320 °C and hence can be used in device fabrication.

  5. Resonance Enhanced Multi-Photon Ionization (rempi) and Double Resonance Uv-Uv and Ir-Uv Spectroscopic Investigation Isocytosine

    Science.gov (United States)

    Lee, Seung Jun; Min, Ahreum; Ahn, Ahreum; Moon, Cheol Joo; Choi, Myong Yong; Ishiuchi, Shun-Ichi; Miyazaki, Mitsuhiko; Fujii, Masaaki

    2013-06-01

    Isocytosine(iC), 2-aminouracil, is a non-natural nucleobase and its functional group's positions resemble those of guanine; therefore, its spectroscopic investigation is worthy of attention especially for the natural/unnatural base pairs with guanine and isoguanine. In this study, resonance enhanced multi-photon ionization (REMPI) and UV/IR-UV double resonance spectra of iC in the gas phase are presented. The collaboration work between Tokyo Institute of Technology, Japan and Gyeongsang National University, Korea using laser ablation and thermal evaporation, respectively, for producing jet-cooled iC is presented and discussed. The REMPI spectrum of iC monomers is recorded in the spectral range of 35000 to 36400cm-1, showing very congested π-π* vibronic bands. UV-UV hole burning spectroscopy is further conducted to investigate the conformational landscapes of iC monomers. Moreover, the presence of free OH band from IR-UV double resonance spectroscopy in combination with quantum chemical calculations convinces that the iC monomer in free-jet expansion experiment is an enol tautomer. However, a possible presence of a keto tautomer of iC may be provided by employing a pico-second experiment on iC.

  6. Spectroscopic investigations on Pr³+ and Nd³+ doped strontium-lithium-bismuth borate glasses.

    Science.gov (United States)

    Rajesh, D; Balakrishna, A; Seshadri, M; Ratnakaram, Y C

    2012-11-01

    Spectroscopic investigations on different concentrations (0.1, 0.5, 1.0, 1.5 and 2.0mol%) of Pr(3+) and Nd(3+) doped strontium lithium bismuth borate glasses have been done. X-ray diffraction, SEM with EDS, absorption and luminescence spectra were recorded for all the glass matrices and analyzed. X-ray diffraction profiles and SEM images conformed amorphous nature of investigated glass samples. EDS spectra of host glass and Pr(3+)doped glass matrices gave information about the chemical composition of glass samples. From the absorption spectra of Pr(3+) and Nd(3+) ions, Judd-Ofelt (J-O) intensity parameters (Ω(λ),λ=2, 4 and 6) have been calculated and compared with other glass matrices. The emission characteristics such as radiative lifetimes (τ(R)), measured and calculated branching ratios (β) and stimulated emission cross-sections (σ(P)) have been obtained for the observed emission transitions of Pr(3+) and Nd(3+) ions in the above glass matrix for all the concentrations. From the emission spectra of Pr(3+) and Nd(3+) doped glass matrices, the effect of concentration on the quenching of intensity of (1)D(2)→(3)H(4) transition of Pr(3+) ion and (4)F(3/2)→(4)I(9/2), (4)I(11/2) and (4)I(13/2) transitions of Nd(3+) have been studied and discussed.

  7. Nano sized Powder of Jackfruit Seed: Spectroscopic and Anti-microbial Investigative Approach

    CERN Document Server

    Theivasanthi, T; Palanivelu, M; Alagar, M

    2011-01-01

    This work reports aspect related to nano-sized particles of jackfruit seed. FTIR spectrum was recorded for functional groups analysis and EDAX analysis was done to identify the various elements of the sample. Both FTIR and EDAX analysis results indicated the presence of Starch. FTIR analysis confirmed the availability of anti-microbial Sulphur derivatives compounds. Microbiology assay found that jackfruit seed nanoparticles were effective against Escherichia coli and Bacillus megaterium bacteria. This work also investigated about the dual-function of the sample i.e. food ingredients possessing antimicrobial activities. Specific surface area of bacteria analysis revealed that it played a major role while on reactions with jackfruit seed nanoparticles.

  8. Co speciation in hardened cement paste: a macro- and micro-spectroscopic investigation.

    Science.gov (United States)

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

    2007-03-15

    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, Co uptake by hardened cement paste (HCP) 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) on powder material (bulk-XAS) was used to determine the local environment of Co in cement systems. Bulk-XAS investigations were complemented with micro-beam investigations to probe the inherent microscale heterogeneity of cement by using micro-X-ray-fluorescence (micro-XRF) and micro-XAS. Micro-XRF was used to gain information on the spatial heterogeneity of the Co distribution, whereas micro-XAS was employed to determine the speciation of Co on the microscale. The Co-doped HCP samples hydrated for time-scales from 1 hour up to 1 year were prepared under normal atmosphere, to simulate similar conditions as for waste packages. To investigate the role of oxygen, further samples were prepared in the absence of oxygen. The study showed that, for the samples prepared in air, Co(II) is oxidized to Co(III) after 1 hour of hydration time. Moreover, the relative amount of Co(III) increases with increasing hydration time. The study further revealed that Co(II) is predominately present as a Co-hydroxide-like phase and/or Co-phyllosilicates, whereas Co(III) tends to be incorporated into a CoOOH-like phase and/or Co-phyllomanganates. In contrast to samples prepared in air, XAS experiments with samples prepared in the absence of oxygen revealed solely the presence of Co(II). This finding indicates that oxygen plays an important role for Co oxidation in cement. Furthermore, the study suggests that Co

  9. IR spectroscopic investigation of the structure of water-fuel microemulsion for diesel engines

    Science.gov (United States)

    Vettegren', V. I.; Mamalimov, R. I.; Lozhkin, V. N.; Morozov, V. A.; Lozhkina, O. V.; Pimenov, Yu. A.

    2016-09-01

    The structures of a microemulsion formed by a surfactant (ammonium oleate), water drops of a linear size of 1-3 µm, and a diesel fuel has been investigated using IR spectroscopy. It has been found that ammonium oleate molecules in the microemulsion are dissociated on the positive NH4 + ion and the negative ion of the remaining part of the molecule, which forms the hydrogen bond with water molecules. This increases the rate of water, evaporation and leads to the more complete combustion of the diesel fuel. As a result, the concentration of harmful nitrogen oxides and soot particles in the exhaust gas of the diesel engine decreases.

  10. The analytical investigations of ancient pottery from Kaveripakkam, Vellore dist, Tamilnadu by spectroscopic techniques

    Science.gov (United States)

    Ravisankar, R.; Naseerutheen, A.; Raja Annamalai, G.; Chandrasekaran, A.; Rajalakshmi, A.; Kanagasabapathy, K. V.; Prasad, M. V. R.; Satpathy, K. K.

    2014-03-01

    Analytical investigations using Fourier Transform infrared spectroscopy (FT-IR), Powder X-ray Diffraction (PXRD), Thermal Analysis (TG-DTA), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF) were carried out on ancient pottery fragments from Kaveripakkam, in order to outline manufacturing skills, technology information, firing condition and temperature of potteries. The whole set of data showed the firing temperature in the range of 800-900 °C. The analytical characterization of the potsherds, by different complimentary techniques has allowed to identifying the raw materials and technology applied by the ancient artisans.

  11. Synthesis, X-ray crystallography, thermal studies, spectroscopic and electrochemistry investigations of uranyl Schiff base complexes.

    Science.gov (United States)

    Asadi, Zahra; Shorkaei, Mohammad Ranjkesh

    2013-03-15

    Some tetradentate salen type Schiff bases and their uranyl complexes were synthesized and characterized by UV-Vis, NMR, IR, TG, C.H.N. and X-ray crystallographic studies. From these investigations it is confirmed that a solvent molecule occupied the fifth position of the equatorial plane of the distorted pentagonal bipyramidal structure. Also, the kinetics of complex decomposition by using thermo gravimetric methods (TG) was studied. The thermal decomposition reactions are first order for the studied complexes. To examine the properties of uranyl complexes according to the substitutional groups, we have carried out the electrochemical studies. The electrochemical reactions of uranyl Schiff base complexes in acetonitrile were reversible.

  12. Biological applications and spectroscopic investigations of 4-nitrophenol-urea dimer: A DFT approach

    Science.gov (United States)

    Beaula, T. Joselin; Muthuraja, P.; Dhandapani, M.; Joe, I. Hubert; Rastogi, V. K.; Jothy, V. Bena

    2016-02-01

    Molecular geometry of grown crystal 4-nitrophenol-urea has been evaluated and compared with XRD data while the crystalline nature of the compound has been confirmed by PXRD study. Vibrational analysis has been performed using NCA and dielectric studies have been carried out at room temperature. NBO analysis has been applied in comparative study of charge delocalization. Molecular orbital contributions have been investigated by TDOS and αβDOS. Enhancement of microbial treatments against bacteria and fungi has been assessed and a remarkable efficiency has been recorded.

  13. A spectroscopic survey of Herbig Ae/Be stars with X-Shooter II: Accretion diagnostic lines

    CERN Document Server

    Fairlamb, John R; Mendigutia, Ignacio; Ilee, John D; Ancker, Mario E van den

    2016-01-01

    The Herbig Ae/Be stars (HAeBes) allow an exploration of the properties of Pre-Main Sequence(PMS) stars above the low-mass range ($8{\\rm\\thinspace M_{\\odot}}$). This paper is the second in a series exploring accretion in 91 HAeBes with Very Large Telescope/X-shooter spectra. Equivalent width measurements are carried out on 32 different lines, spanning the UV to NIR, in order to obtain their line luminosities. The line luminosities were compared to accretion luminosities, which were determined directly from measurements of an UV-excess. When detected, emission lines always demonstrate a correlation with the accretion luminosity, regardless of detection frequency. The average relationship between accretion luminosity and line luminosity is found to be ${\\thinspace L_{\\rm acc}}\\propto{\\thinspace L_{\\rm line}}^{1.16 \\pm 0.15}$. This is in agreement with the findings in Classical T Tauri stars, although the HAeBe relationship is generally steeper, particularly towards the Herbig Be mass range. Since all observed li...

  14. Impedance Spectroscopic Investigation of the Degraded Dye-Sensitized Solar Cell due to Ageing

    Directory of Open Access Journals (Sweden)

    Parth Bhatt

    2016-01-01

    Full Text Available This paper investigates the effect of ageing on the performance of dye-sensitized solar cells (DSCs. The electrical characterization of fresh and degraded DSCs is done under AM1.5G spectrum and the current density-voltage (J-V characteristics are analyzed. Short circuit current density (JSC decreases significantly whereas a noticeable increase in open circuit voltage is observed. These results have been further investigated electroanalytically using electrochemical impedance spectroscopy (EIS. An increase in net resistance results in a lower JSC for the degraded DSC. This decrease in current is mainly due to degradation of TiO2-dye interface, which is observed from light and dark J-V characteristics and is further confirmed by EIS measurements. A reduction in the chemical capacitance of the degraded DSC is observed, which is responsible for the shifting of Fermi level with respect to conduction band edge that further results in an increase of open circuit voltage for the degraded DSC. It is also confirmed from EIS that the degradation leads to a better contact formation between the electrolyte and Pt electrode, which improves the fill factor of the DSC. But the recombination throughout the DSC is found to increase along with degradation. This study suggests that the DSC should be used under low illumination conditions and around room temperature for a longer life.

  15. 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.

  16. Molecular structure activity on pharmaceutical applications of Phenacetin using spectroscopic investigation

    Science.gov (United States)

    Madanagopal, A.; Periandy, S.; Gayathri, P.; Ramalingam, S.; Xavier, S.

    2017-01-01

    The pharmaceutical compound; Phenacetin was investigated by analyzing FT-IR, FT-Raman and 1H &13C NMR spectra. The hybrid efficient computational calculations performed for computing physical and chemical parameters. The cause of pharmaceutical activity due to the substitutions; carboxylic, methyl and amine groups in appropriate positions on the pedestal compound was deeply investigated. Moreover, 13C NMR and 1H NMR chemical shifts correlated with TMS standard to explain the truth of compositional ratio of base and ligand groups. The bathochromic shift due to chromophores over the energy levels in UV-Visible region was strongly emphasized the Anti-inflammatory chemical properties. The chemical stability was pronounced by the strong kubo gap which showed the occurring of charge transformation within the molecule. The occurrence of the chemical reaction was feasibly interpreted by Gibbs free energy profile. The standard vibrational analysis stressed the active participation of composed ligand groups for the existence of the analgesic as well as antipyretic properties of the Phenacetin compound. The strong dipole interaction energy utilization for the transition among non-vanishing donor and acceptor for composition of the molecular structure was interpreted.

  17. Probing the Physics of Narrow Line Regions in Active Galaxies II: The Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7)

    CERN Document Server

    Dopita, Michael A; Davies, Rebecca; Kewley, Lisa; Hampton, Elise; Scharwächter, Julia; Sutherland, Ralph; Kharb, Preeti; Jose, Jessy; Bhatt, Harish; Ramya, S; Jin, Chichuan; Banfield, Julie; Zaw, Ingyin; Juneau, Stéphanie; James, Bethan; Srivastava, Shweta

    2015-01-01

    Here we describe the \\emph{Siding Spring Southern Seyfert Spectroscopic Snapshot Survey} (S7) and present results on 64 galaxies drawn from the first data release. The S7 uses the Wide Field Spectrograph (WiFeS) mounted on the ANU 2.3m telescope located at the Siding Spring Observatory to deliver an integral field of $38\\times25$~ arcsec at a spectral resolution of $R=7000$ in the red ($530-710$nm), and $R=3000$ in the blue ($340-560$nm). {From these data cubes we have extracted the Narrow Line Region (NLR) spectra from a 4 arc sec aperture centred on the nucleus. We also determine the H$\\beta$ and [OIII]~$\\lambda$5007 fluxes in the narrow lines, the nuclear reddening, the reddening-corrected relative intensities of the observed emission lines, and the H$\\beta$ and \\lOIII\\ luminosities {determined from spectra for which the stellar continuum has been removed.} We present a set of images of the galaxies in [OIII]~$\\lambda$5007, [NII]~$\\lambda$6584 and H$\\alpha$ which serve to delineate the spatial extent of th...

  18. Spectroscopic investigation of an intrinsic room temperature ferromagnetism in Co doped ZnO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    N, Srinatha [Department of Physics, JB Campus, Bangalore University, Bangalore 560056 (India); Angadi, Basavaraj, E-mail: brangadi@gmail.com [Department of Physics, JB Campus, Bangalore University, Bangalore 560056 (India); Nair, K.G.M. [UGC-DAE-CSR, Kalpakkam Node, Kalpakkam, Kokilamedu 603 102 (India); Deshpande, Nishad G.; Shao, Y.C.; Pong, Way-Faung [Department of Physics, Tamkang University, Tamsui, Taipei 251, Taiwan (China)

    2014-08-15

    Highlights: • For the first time L-Valine was used as a fuel to synthesize Co:ZnO nanoparticles by solution combustion method. • Single phase and ferromagnetic nature were confirmed through XRD, SQUID, NEXAFS and XMCD. • Through NEXAFS and XMCD, the effect of ‘Co’ substitution at O K-edge, Co L{sub 3,2} edge, Zn L{sub 3,2} edge have been investigated. • Spectral features of NEXAFS and XMCD confirms an intrinsic RTFM by substitution of ‘Co{sup 2+}’ at ‘Zn{sup 2+}’ site and rules out the presence of secondary phases. - Abstract: Pure and Co substituted ZnO nano crystalline particles were prepared by solution combustion technique using L-Valine as a fuel. As synthesized powder samples were characterized by X-ray diffractometer and SQUID magnetometer to confirm the formation of single phase wurtzite structure and to study the bulk magnetic response of the sample, respectively. Magnetic studies show that Co doped ZnO nanoparticles exhibit ferromagnetism (FM) at room temperature (RT). Furthermore, the electronic structure and element specific magnetic properties were investigated by near-edge X-ray absorption fine structure (NEXAFS) and X-ray magnetic circular dichroism (XMCD) measurements, respectively. The effect of Co substitution on the spectral features of Co–ZnO at O K-edge, Co L{sub 3,2} edge, Zn L{sub 3,2} edge have been investigated. The spectral features of NEXAFS at Co L{sub 3,2} edge is entirely different from the spectral features of metallic clusters and other impurity phases, which rules out the presence of impurity phases. The valence state of ‘Co’ ion is found to be in +2 state. The FM nature of the sample was confirmed through XMCD spectra, which is due to the incorporation of divalent ‘Co’ ions. Hence the presented results confirm the substitution of ‘Co’ ions at ‘Zn’ site in the host lattice, which is responsible for the RTFM.

  19. 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

    2016-01-01

    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, 1H and 13C 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.

  20. Spectroscopic investigations on the interactions between isopropanol and trypsin at molecular level.

    Science.gov (United States)

    Hu, Xinxin; Yu, Zehua; Liu, Rutao

    2013-05-01

    The toxicity of hydroxyl group of isopropanol to trypsin in aqueous solution was investigated by techniques including UV-visible absorption spectroscopy, fluorescence spectroscopy, circular dichroism (CD) spectroscopy, enzyme activity assay and molecular docking technology. The results of UV-visible absorption spectroscopy and CD spectra indicate that isopropanol could change the secondary structure of trypsin by increasing the content of α-helix and decreasing the content of β-sheet. The tertiary structure of trypsin was also changed owing to the loss of environmental asymmetry of amino acid residues. Isopropanol bound into a hydrophobic cavity on the surface of trypsin by a hydrogen bond located between the hydrogen atom on the hydroxyl of isopropanol and the oxygen atoms on SER 214 and hydrophobic interaction, as the molecular docking results showed. In addition, isopropanol could affect the function of trypsin by increasing its catalytic activity.

  1. Femtosecond laser irradiation of indium phosphide in air: Raman spectroscopic and atomic force microscopic investigations

    Energy Technology Data Exchange (ETDEWEB)

    Bonse, J.; Wrobel, J.M.; Brzezinka, K.-W.; Esser, N.; Kautek, W

    2002-12-30

    Surface modification and ablation of crystalline indium phosphide was performed with single and double 130 fs pulses from a Ti:sapphire laser. The morphological features resulting from laser processing, have been investigated by means of micro Raman spectroscopy as well as by optical, atomic force and scanning electron microscopy. The studies indicate amorphous, ablated and recrystallized zones on the processed surface. In the single-pulse irradiation experimentsveral different threshold fluences could be assigned to the processes of melting, ablation and polycrystalline resolidification. Residual stress has been detected within the irradiated areas. Double-pulse exposure experiments have been analyzed in order to clarify the effect of cumulative damage in the ablation process of indium phosphide.

  2. A DFT investigation of structure, spectroscopic properties and tautomerism of the anticonvulsant drug Lyrica

    Science.gov (United States)

    Sadeghzade, Zohre; Beyramabadi, S. Ali; Morsali, Ali

    2015-03-01

    The Lyrica (Pregabalin) is a novel anticonvulsant and neuropathic pain drug, which could exist as four possible conformers. Herein, employing density functional theory (DFT), and handling the solvent effects with the PCM model, the structural parameters, energetic behavior, natural bond orbital analysis (NBO), as well as tautomerism mechanization of the Lyrica are investigated. The L1 (-OH form) is the most stable conformer of the Lyrica, which can be tautomerized to the L5 (-NH form) tautomer. The tautomerism reaction includes an intramolecular-proton transfer, which affects considerably the structural parameters and atomic charges of the L1. The DFT-computed NMR chemical shifts and IR vibrational frequencies are good in agreement with the experimental values, confirming suitability of the optimized geometry for the Lyrica.

  3. Spectroscopic Investigation on the Interaction of a Cyanine Dye with Serum Albumins

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ya-Zhou; YANG Qian-Fan; DU Hong-Yan; TANG Ya-Lin; XU Guang-Zhi; YAN Wen-Peng

    2008-01-01

    The interactions of a cyanine dye with human serum albumin (HSA) and bovine serum albumin (BSA) have been investigated by using absorption and fluorescence spectra.Absorption spectral studies show that binding to the serum albumins leads to a bathochromic shift of the monomer band together with a notable intensity change.Furthermore, the number of binding sites (n) was identified by the absorption spectra.There is a constant enhancement of fluorescence quantum yield when the cyanine dye complexes with HSA or BSA.The apparent binding constant (Ka) and the free energy changes (△G) were obtained by analysis of fluorescence data of the cyanine dye in the absence and presence of HSA and BSA.Compared to BSA, HSA associates with the dye in a stronger way.

  4. Interaction of sulfanilamide and sulfamethoxazole with bovine serum albumin and adenine: spectroscopic and molecular docking investigations.

    Science.gov (United States)

    Rajendiran, N; Thulasidhasan, J

    2015-06-05

    Interaction between sulfanilamide (SAM) and sulfamethoxazole (SMO) with BSA and DNA base (adenine) was investigated by UV-visible, fluorescence, cyclic voltammetry and molecular docking studies. Stern-Volmer fluorescence quenching constant (Ka) suggests SMO is more quenched with BSA/adenine than that of SAM. The distance r between donor (BSA/adenine) and acceptor (SAM and SMO) was obtained according to fluorescence resonance energy transfer (FRET). The results showed that hydrophobic forces, electrostatic interactions, and hydrogen bonds played vital roles in the SAM and SMO with BSA/adenine binding interaction. During the interaction, sulfa drugs could insert into the hydrophobic pocket, where the non-radioactive energy transfer from BSA/adenine to sulfa drugs occurred with high possibility. Cyclic voltammetry results suggested that when the drug concentration is increased, the anodic electrode potential deceased. The docking method indicates aniline group is interacted with the BSA molecules. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. A spectroscopic and theoretical investigation of the proton-transfer laser. [Fisetin and 3-hydroxyflavone

    Energy Technology Data Exchange (ETDEWEB)

    Parthenopoulos, D.A.

    1988-01-01

    The lasing characteristics and the spectroscopy of intramolecular proton-transfer molecules were investigated in nonpolar and polar solvents. In addition, molecular orbital calculations on intramolecular proton-transfer molecules were performed. The efficient generation of coherent stimulated emission from 3-hydroxyflavone (3-HF) and fisetin, two molecules that exhibit intramolecular proton transfer was shown. Amplified spontaneous emission from 3-HF is achieved in polar aprotic and moderately protic solvents. The observed shifts of the tautomer fluorescence are attributed to hydrogen bonding interactions with the solvent. In contrast, 3-hydroxychromone does not exhibit amplified spontaneous emission in various solvents and concentrations. Picosecond transient absorption experiments reveal the existence of absorption bands overlapping the emission, which leads to high-loss terms in the gain equation.

  6. Spectroscopic investigation of the interaction of p-benzoquinone with casein in the solid state.

    Science.gov (United States)

    Vieira, Isadora S; Zaia, Dimas A M; Balena, Solange P; Mangrich, Antonio S; de Santana, Henrique

    2010-02-01

    The reaction between p-benzoquinone (PBQ) and casein (protein) in the solid state was studied. After reaction with protein, the FT-IR spectra showed a new band at 1215 cm(-1), with an intense sign attributed for casein/PBQ product. An optimum amount of PBQ for determination of the product when mixed with casein was 100mg and a reaction time of 30 min. The product was stable for a period of 24h after the reacting by heating. The interaction of PBQ with casein was investigated by FT-IR, reflectance, Raman and EPR spectroscopies. The reaction between PBQ and casein in the solid state yields a radical species (p-benzosemiquinone) that it is stabilized by the presence of p-biphenolate and p-benzoquinone species in the solid state. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  7. Glass transition of polystyrene (PS) studied by Raman spectroscopic investigation of its phenyl functional groups

    Science.gov (United States)

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

    2017-01-01

    In polymeric materials the glass transition (GT) is a well-known and very important relaxation process related to movements of functional groups in the polymeric chain. In this work, we show the potential of Raman spectroscopy for exploring the GT process in the polymer polystyrene. We collected Raman spectra during a step-by-step heating process of the sample, which allowed us to collect signatures of the GT process from peak parameters of specific vibrational modes, and to verify the GT temperature. Results of the latter were in accordance with published values obtained via other methods. We identified the aromatic ring vibrational modes of the phenyl functional groups to be those which, due to steric hindrance, suffer the largest influence during the GT process. This confirms that Raman spectroscopy can be used as a complementary technique to perform GT investigations in polymeric materials due to its sensitivity to small intermolecular changes affecting vibrational properties of relevant functional side groups.

  8. 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.

  9. Interaction of cyclodextrins with human and bovine serum albumins: A combined spectroscopic and computational investigation

    Indian Academy of Sciences (India)

    Saptarshi Ghosh; Bijan Kumar Paul; Nitin Chattopadhyay

    2014-07-01

    Interaction of cyclodextrins (CDs) with the two most abundant proteins, namely human serum albumin (HSA) and bovine serum albumin (BSA), has been investigated using steady-state and time-resolved fluorometric techniques, circular dichroism measurements and molecular docking simulation. The study reveals that the three CDs interact differently on the fluorescence and fluorescence lifetimes of the serum albumins. However, fluorescence anisotropy and circular dichroism are not affected. Depending on their size, different CDs bind to the serum albumins in different positions, resulting in changes in the spectral behaviour of the proteins. Docking study suggests the probable binding sites of the three CDs with the proteins. Combined experimental and computational studies imply that sufficiently high concentration of CDs causes loosening of the rigid structures of these transport proteins, although their secondary structures remain intact. Thus, CDs are found to be safe for the serum proteins from the structural point of view.

  10. Spectroscopic and molecular modeling investigation on the binding of a synthesized steroidal amide to protein

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hua-xin, E-mail: h.x.zhang@yeah.net; Liu, E.

    2014-09-15

    Owing to the various valuable biological activities, steroidal amides have become a hot topic in steroidal pharmaceutical chemistry. In this paper, an anti-tumor steroid derivate (DAAO) was synthesized and identified. The interaction between DAAO and human serum albumin (HSA) was studied by fluorescence spectra, circular dichroism (CD) spectra, molecular modeling and molecular probe techniques. The results suggested that DAAO had reacted with HSA through hydrogen bonds and van der Waals power. The formation of DAAO–HSA complex at ground state led to static quenching of HSA's fluorescence. The number of binding sites, binding constants, enthalpy change (ΔH{sup θ}), Gibbs free energy change (ΔG{sup θ}) and entropy change (ΔS{sup θ}) were calculated at different temperatures based on fluorescence quenching theory and classic equation. Molecular modeling investigation indicated that DAAO was more inclined to absorb on Sudlow's site I in subdomain IIA of HSA molecule on grounds of the lowest energy principle and steric hindrance effect. The binding location was further confirmed by fluorescence probe experiment using warfarin (site I probe) for displacement. Furthermore, the conformational changes of HSA in presence of DAAO were investigated by CD spectra. The results could provide new evidence explaining the relationship between the chemical structure and biological activity and may be useful for understanding the anti-cancer mechanism of steroidal drug. - Highlights: • A designed steroidal amide compound (DAAO) was synthesized by introducing amido bonds into a steroid nucleus. • DAAO binds to Sudlow's site I in HSA through hydrogen bonds and van der Waals power. • The interaction was a spontaneous and exothermic process with modest degree of reversibility. • The secondary structure of HSA and the microenvironment of TRP214 altered. • Amido bond in steroid nucleus (–NH–CO–) plays important role in stabling the structure of

  11. Mode of bindings of zinc oxide nanoparticles to myoglobin and horseradish peroxidase: A spectroscopic investigations

    Science.gov (United States)

    Mandal, Gopa; Bhattacharya, Sudeshna; Ganguly, Tapan

    2011-07-01

    The interactions between two heme proteins myoglobin (HMb) and horseradish peroxidase (HRP) with zinc oxide (ZnO) nanoparticles are investigated by using UV-vis absorption, steady state fluorescence, synchronous fluorescence, time-resolved fluorescence, FT-IR, atomic force microscopy (AFM) and circular dichroism (CD) techniques under physiological condition of pH˜7.4. The presence of mainly static mode in fluorescence quenching mechanism of HMb and HRP by ZnO nanoparticle indicates the possibility of formation of ground state complex. The processes of bindings of ZnO nanoparticles with the two proteins are spontaneous molecular interaction procedures. In both cases hydrogen bonding plays a major role. The circular dichroism (CD) spectra reveal that a helicity of the proteins is reduced by increasing ZnO nanoparticle concentration although the α-helical structures of HMb and HRP retain their identity. On binding to the ZnO nanoparticles the secondary structure of HRP molecules (or HMb molecules) remains unchanged while there is a substantial change in the environment of the tyrosin active site in case of HRP molecules and tryptophan active site in case of HMb molecules. Tapping mode atomic force microscopy (AFM) was applied for the investigation the structure of HRP adsorbed in the environment of nanoparticles on the silicon and on the bare silicon. HRP molecules adsorb and aggregate on the mica with ZnO nanoparticle. The aggregation indicates an attractive interaction among the adsorbed molecules. The molecules are randomly distributed on the bare silicon wafer. The adsorption of HRP in the environment of ZnO nanoparticle changes drastically the domains due to a strong interaction between HRP and ZnO nanoparticles. Similar situation is observed in case of HMb molecules. These findings demonstrate the efficacy of biomedical applications of ZnO nanoparticles as well as in elucidating their mechanisms of action as drugs in both human and plant systems.

  12. IR spectroscopic investigation of charge transfer at interfaces of organic semiconductors (Conference Presentation)

    Science.gov (United States)

    Beck, Sebastian; Hillebrandt, Sabina; Pucci, Annemarie

    2016-09-01

    In organic electronics, the interactions at interfaces between different organic and inorganic layers play a decisive role for device functionality and performance. Therefore, more detailed, quantitative studies of charge transfer (CT) at such interfaces are needed to improve the understanding of the underlying mechanisms. In this study we show that in-situ infrared spectroscopy can be used to investigate CT effects at organic/organic as well as inorganic/organic interfaces quantitatively. For different combinations of commonly used organic semiconductors such as 4,4´-bis(N-carbazolyl)-1,1´-biphenyl (CBP) or fluorinated zinc phthalocyanine (F4ZnPc) and inorganic contact materials such as molybdenum oxide (MoO3) or indium tin oxide (ITO) the CT at the interface was investigated using in-situ IR spectroscopy. The measurements were carried out under UHV conditions during film growth what enables a careful study of the influence of different parameters such as substrate temperature and layer thickness in a controlled way even on a nanometer scale. When the organic molecules are deposited onto the underlying layer charged and non-charged species form which can be identified and quantitatively analyzed in the IR spectra. It was also found that the deposition sequence can strongly influence the interface properties what might have strong implications on the layer stack design. For example, when MoO3 is deposited onto CBP, the CBP layer is strongly doped, due to diffusion of the deposited transition metal oxide clusters into the organic layer. Financial support by BMBF (project INTERPHASE) is gratefully acknowledged.

  13. Effect of chitosan/riboflavin modification on resin/dentin interface: spectroscopic and microscopic investigations.

    Science.gov (United States)

    Daood, Umer; Iqbal, Kulsum; Nitisusanta, Lorraine I; Fawzy, Amr S

    2013-07-01

    The aim of this study is to investigate the morphological and chemical changes of demineralized dentin collagen-matrix and resin/dentin interface associated with chitosan/riboflavin modification. Dentin disc specimens were prepared from sound molars, acid-etched with 35% phosphoric acid and modified with either 0.1% riboflavin or chitosan/riboflavin (Ch/RF ratios 1:4 or 1:1) and photo-activated by UVA. Morphological and chemical changes associated with surface modification were characterized by SEM and micro-Raman spectroscopy. Dentin surfaces of sound molars were exposed, acid-etched, and modified as described before. Etch-and-rinse dentin adhesive was applied, light-cured, and layered with resin-restorative composite. The resin infiltration and resin/dentin interface were characterized by micro-Raman spectroscopy and SEM. An open-intact collagen network-structure, formation of uniform hybrid-layer and higher resin infiltration were found with 0.1%RF and Ch/RF 1:4 modifications. Raman analysis revealed chemical changes and shifts in Amide bands with the modification of dentin collagen-matrix. The use of riboflavin and chitosan/riboflavin formulations to modify dentin-collagen matrix, with the defined ratios, stabilizes the collagen fibrillar network and enhances resin infiltration and hybrid layer formation. These preliminary results are encouraging for subsequent consideration of chitosan/riboflavin modification in adhesive dentistry.

  14. Structural and spectroscopic investigation of lanthanum-substituted strontium-oxybritholites

    Indian Academy of Sciences (India)

    K Boughzala; S Nasr; E Ben Salem; F Kooli; K Bouzouita

    2009-05-01

    Lanthanum-substituted strontium-oxybritholites, Sr10-La(PO4)6-(SiO4)O with = 0, 2 and 4, prepared by solid state reaction were investigated by chemical analysis, powder X-ray diffraction, Raman and 29Si MAS NMR spectroscopies. The refinements of powder XRD patterns of the substituted compounds by the Rietveld method showed that the lanthanum occupied the two metal sites, i.e. (4f) and (6h) sites into the apatite structure, with a clear preference for the (6h) sites. A progressive shift of the free oxygen O(4) towards the centre of the triangles formed by the metal-atoms in the (6h) positions was observed when the lanthanum content increased. It led to the formation of a Sr/La(2)-O(4) strong bond, which might have increased the stability of these compounds. The bands of Raman spectra were assigned to the vibration modes of PO4 and SiO4 groups. The comparison of the results of 29Si MAS NMR analysis with those obtained with the 31P previously reported, suggested that both species occupied the same crystallographic sites.

  15. Investigation on the inclusion and toxicity of acriflavine with cyclodextrins: A spectroscopic approach

    Science.gov (United States)

    Manivannan, C.; Meenakshi Sundaram, K.; Sundararaman, M.; Renganathan, R.

    2014-03-01

    Acriflavine hydrochloride (AFN) is a prospective drug worn in the eradication of HIV1 infection. The toxicity and adverse side effects renders the potent drug to limits its usage. However, to overcome the dilemma we have aimed to select carriers with great complexation efficiencies in different cyclodextrins (CDs) of varying cavity size. The interaction of AFN with α, β and γ-CDs were investigated using absorption and steady state as well as lifetime measurements. From the obtained data it was found that AFN fits in the cavity of α and β-CDs but unable to form inclusion complex with γ-CD. The effect of quencher molecules during the inclusion phenomena of AFN with CDs was explored via steady state measurements. The nature of binding forces responsible for the inclusion of AFN with CDs was discussed by using thermodynamic parameters. Using Benesi-Hildebrand equation the stoichiometry of AFN with CDs was predominantly found to be 1:1. To get deeper in situ, the in vitro toxicity of AFN and its complexation product were probed by Artemia salina sp. The toxicity of AFN was reduced when complexed with α and β-CDs.

  16. Micro-spectroscopic investigation of selenium-bearing minerals from the Western US Phosphate Resource Area

    Directory of Open Access Journals (Sweden)

    Gunter Mickey E

    2005-01-01

    Full Text Available Mining activities in the US Western Phosphate Resource Area (WPRA have released Se into the environment. Selenium has several different oxidation states and species, each having varying degrees of solubility, reactivity, and bioavailability. In this study we are investigating the speciation of Se in mine-waste rocks. Selenium speciation was determined using bulk and micro-x-ray absorption spectroscopy (XAS, as well as micro-x-ray fluorescence mapping. Rocks used for bulk-XAS were ground into fine powders. Shale used for micro-XAS was broken along depositional planes to expose unweathered surfaces. The near edge region of the XAS spectra (XANES for the bulk rock samples revealed multiple oxidation states, with peaks indicative of Se(-II, Se(IV, and Se(+VI species. Micro-XANES analysis of the shale indicated that three unique Se-bearing species were present. Using the XANES data together with ab initio fitting of the extended x-ray absorption fine structure region of the micro-XAS data (micro-EXAFS the three Se-bearing species were identified as dzharkenite, a di-selenide carbon compound, and Se-substituted pyrite. Results from this research will allow for a better understanding of the biogeochemical cycling of Se in the WPRA.

  17. Mid-infrared spectroscopic investigation of the perfect vitrification of poly(ethylene glycol) aqueous solutions.

    Science.gov (United States)

    Gemmei-Ide, Makoto; Miyashita, Takashi; Kagaya, Shigehiro; Kitano, Hiromi

    2015-10-01

    Crystallization/recrystallization behaviors of poly(ethylene glycol) (PEG) aqueous solutions with water contents (WC's) of ∼36-51 wt % were investigated by temperature-variable mid-infrared spectroscopy. At a WC of 43.2 wt %, crystallization and recrystallization of water and PEG were not observed. At this specific WC value (WCPV), perfect vitrification occurred. Below and above the WCPV value, crystallization/recrystallization behaviors changed drastically. The crystallization temperature below WCPV (237 K) was ∼10 K greater than that above WCPV (226 K). Recrystallization above and below WCPV occurred in one (213 K) and two (198 and 210 K) steps, respectively. These findings resulted from the difference in the (re)crystallization behaviors of water molecules associated with PEG chains with helical and random-coil conformations. These two types of water molecules might have limiting concentrations for their (re)crystallization, indicating that perfect vitrification might have occurred when the concentrations of the two types of water molecules were less than the limiting concentrations of their (re)crystallization.

  18. Spectroscopic investigation of plasma electrolytic borocarburizing on q235 low-carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Run [Key Laboratory for Beam Technology and Materials Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Zhenjiang Watercraft College, Zhenjiang 212000, Jiangsu (China); Wang, Bin; Wu, Jie [Key Laboratory for Beam Technology and Materials Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Xue, Wenbin, E-mail: xuewb@bnu.edu.cn [Key Laboratory for Beam Technology and Materials Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Jin, Xiaoyue; Du, Jiancheng; Hua, Ming [Key Laboratory for Beam Technology and Materials Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China)

    2014-12-01

    Highlights: • The plasma discharge behaviors for PEB/C on steels were evaluated by OES. • Electron temperature, concentration, atomic ionization degree were calculated. • The decomposition mechanism of electrolyte and was analyzed. - Abstract: A plasma electrolytic borocarburizing process (PEB/C) in borax electrolyte with glycerin additive was employed to fabricate a hardening layer on Q235 low-carbon steel. Optical emission spectroscopy (OES) was utilized to investigate the spectroscopy characteristics of plasma discharge around the steel during PEB/C process. Some plasma parameters were calculated in terms of OES. The electron temperature and electron concentration in plasma discharge zone is about 3000–12,000 K and 2 × 10{sup 22} m{sup −3}–1.4 × 10{sup 23} m{sup −3}. The atomic ionization degrees of iron, carbon and boron are 10{sup −16}–10{sup −3}, and 10{sup −23}–10{sup −6}, 10{sup −19}–10{sup −4}, respectively, which depend on discharge time. The surface morphology and cross-sectional microstructure of PEB/C hardening layer were observed, and the electrolyte decomposition and plasma discharge behaviors were discussed.

  19. Vibrational spectroscopic and structural investigations of 2-amino-6-methoxy-3-nitropyridine: a DFT approach

    Energy Technology Data Exchange (ETDEWEB)

    Premkumar, S.; Asath, R. Mohamed; Mathavan, T.; Benial, A. Milton Franklin [Department of Physics, Nadar Mahajana Sangam S.Vellaichamy Nadar College, Tamil Nadu (India); Rekha, T.N.; Rajkumar, Beulah J.M.; Jawahar, A., E-mail: miltonfranklin@yahoo.com [Department of Physics, Lady Doak College, Tamilnadu (India)

    2015-12-15

    The conformational analysis of 2-amino-6-methoxy-3-nitropyridine molecule (AMNP) has been carried out using density functional theory calculations. The vibrational spectra of the molecule is simulated theoretically and compared experimentally, and the vibrational frequencies are assigned on the basis of potential energy distribution calculations. Electronic properties of the molecule derived from the theoretical ultraviolet–visible spectrum are validated experimentally. The higher non-linear optical activity of the molecule is indicated in the first-order hyperpolarizability calculations. The natural bond orbital and Mulliken atomic charge distribution analysis confirm intramolecular charge transfers and intramolecular interactions. The Frontier molecular orbitals are plotted, and the related molecular properties are calculated and discussed. The molecular electrostatic potential contour map is simulated. As the presence of intramolecular interactions and the associated charge transfers between the pyridine ring of AMNP molecule and the lone pair of oxygen is a common molecular feature of a pharmaceutical compound, this investigation paves the way for its possible biomedical applications. Further, the considerably higher non-linear optical (NLO) activity of the molecule identified suggests its potential applications in the design of new optical materials. (author)

  20. Investigation of Interaction Between Ozagrel and Human Serum Albumin by Spectroscopic and Electrochemical Methods

    Science.gov (United States)

    Li, S.; Wang, Li; Hao, J.; Wang, L.; Tong, Y.-J.; Fu, Z.-Q.; Zhang, A.-P.

    2017-01-01

    The interaction between ozagrel and human serum albumin (HSA) was investigated by fl uorescence spectroscopy, UV-Vis absorption spectroscopy, cyclic voltammetry (CV), differential pulse voltammetry (DPV), and Fourier transform infrared spectroscopy (FTIR) under simulative physiological conditions. The results of CV, DPV and fl uorescence titration revealed that ozagrel bound to HSA. The enthalpy change (ΔH) and the entropy change (ΔS) were derived to be positive values, indicating that the hydrophobic force played the main role in the binding of ozagrel with HSA. The binding distance between ozagrel and HSA was 1.75 nm. Upon binding with ozagrel, the conformation and the secondary structure of HSA molecules were changed. The percentage of α-helix and β-sheet structures decreased by 7.25% and 4.58%, respectively, while the percentage of a β-turn structure increased by 2.67%. The effect of common ions on the binding of ozagrel with HSA was also examined. This study will give an insight into the evaluation of the drug's stabi-lity during transport and its releasing effi ciency at the target site under simulative physiological conditions.

  1. Spectroscopic investigations on SrAl{sub 2}O{sub 4} polymorphs

    Energy Technology Data Exchange (ETDEWEB)

    Boutinaud, P., E-mail: philippe.boutinaud@ensccf.fr [Clermont Université, ENSCCF, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand (France); Boyer, D. [Clermont Université, ENSCCF, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand (France); Perthue, A. [Clermont Université, UBP, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand (France); Mahiou, R. [CNRS, UMR 6296, ICCF, F-63177 Aubière (France); Cavalli, E. [Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Università di Parma, Parma (Italy); Brik, M.G. [Institute of Physics, University of Tartu, Riia 142, Tartu 51014 (Estonia)

    2015-03-15

    Nominally undoped and Eu{sup 3+} or Eu{sup 3+}–Dy{sup 3+} doped SrAl{sub 2}O{sub 4} powders are prepared using source chemicals of standard grade (99–99.99%) by solid state and sol–gel procedures, in order to vary the proportions of monoclinic (P2{sub 1}) and hexagonal (P6{sub 3} and P6{sub 3}22) polymorphs in the compounds. Electron spin resonance reveals systematic contamination of the compounds by transition metal ions. The emission properties of the materials are investigated at 77 K upon UV and blue excitations. The optical features are ascribed, for the essential, to Mn{sup 4+} ions. The spectroscopy of this ion in conjunction with X-ray diffraction data and theoretical considerations is used to individuate P6{sub 3}22, P6{sub 3} and P2{sub 1} phases in the doped and undoped SrAl{sub 2}O{sub 4} powders. - Highlights: • Different polymorphs of SrAl{sub 2}O{sub 4}, undoped or doped with Eu{sup 3+}, were synthesized. • Contamination by transition metals is proved by ESR and photoluminescence. • The Mn{sup 4+} spectroscopy allows the identification of the SrAl{sub 2}O{sub 4} polymorph.

  2. Synthesis and spectroscopic DNA binding investigations of dibutyltin N-(5-chlorosalicylidene)-leucinate

    Science.gov (United States)

    Zhang, Shufang; Yuan, Hongyu; Tian, Laijin

    2017-02-01

    A new dibutyltin N-(5-Chlorosalicylidene)-leucinate (DNCL) was synthesized by the reaction of dibutyltin dichloride with in situ formed potassium N-(5-chlorosalicylidene)-L-isoleucinate 3 characterized by elemental analysis, IR, 1H NMR (1H, 13C and 119Sn) spectra. The interaction between DNCL and calf thymus deoxyribonucleic acid (ctDNA) in a pH 7.4 Tris-HCl buffer solution was investigated by UV-Vis spectroscopy, fluorescence spectroscopy, and viscosity measurements. It was found that DNCL molecules could intercalate into the base pairs of DNA, forming a DNCL-DNA complex with a binding constant of Kf = 5.75 × 105 L mol-1 (310 K). The thermodynamic parameters enthalpy change (ΔH), entropy change (ΔS) and Gibbs free energy (ΔG) were calculated to be 1.16 × 105 J mol-1, 486.5 J K-1 mol -1 and -3.48 × 104 J mol-1 at 310 K, respectively. Hydrophobic interaction was the predominant intermolecular force in stabilizing the DNCL-DNA complex.

  3. Internal structure changes in bleached black human hair resulting from chemical treatments: A Raman spectroscopic investigation

    Science.gov (United States)

    Kuzuhara, Akio

    2014-11-01

    In order to investigate in detail the influence of chemical treatments (reduction, hydrolyzed eggwhite protein (HEWP) treatment, and oxidation) on damaged hair keratin fibers, the structure of cross-sections at various depths of excessively bleached (damaged) black human hair resulting from a permanent waving process was directly analyzed using Raman spectroscopy. It was found that L-cysteine (CYS) largely reacted with the gauche-gauche-gauche (GGG) conformation of disulfide (-SS-) groups (while CYS did not react with the trans-gauche-trans (TGT) conformation). In particular, not only the GGG content, but also the cysteic acid content existing throughout the cortex region of the excessively bleached human hair remarkably decreased by performing the oxidation process after reduction. On the other hand, the GGG content of the excessively bleached black human hair increased, while the TGT content decreased by performing the oxidation process after reduction and then HEWP treatment processes. From these experiments, the authors concluded that some of the keratin associated protein (KAP), which has a rich -SS- content and cysteic acid content was eluted from the cortex region along with the disconnection of -SS- groups, thereby leading to the remarkable reduction in the reconnection of -SS- groups of the excessively bleached black human hair after the permanent waving process (the reduction and oxidation processes). Also, the authors concluded that the HEWP treatment process in the permanent waving process caused the reconstruction of the KAP, thereby contributing to the acceleration of the reconnection of -SS- groups during the oxidation process.

  4. Spectroscopic investigations of arrays containing vertically and horizontally aligned silicon nanowires

    Science.gov (United States)

    Volpati, Diogo; Mårtensson, Niklas; Anttu, Nicklas; Viklund, Per; Sundvall, Christian; Åberg, Ingvar; Bäckström, Joakim; Olin, Håkan; Björk, Mikael T.; Castillo-Leon, Jaime

    2016-12-01

    The properties of nanowire arrays have been investigated mainly in comparison with isolated nanowires or thin films, owing to the difficulty in controlling the nanowire alignment. In this study, we report on arrays containing vertically or horizontally aligned silicon nanowires, whose alignment and structure were determined using x-ray diffraction and scanning electron microscopy. The Raman spectra of the nanowire arrays differ from those of isolated nanowires because of distinct heat dissipation rates of the absorbed energy from the laser, in agreement with recent theoretical calculations. The tailored alignment of the nanowires on solid substrates up to 1 inch of diameter also enabled the observation of resonance modes associated with light trapped into the nanowires. This was proven by comparing the light absorbed and scattered by the arrays, and may be exploited to enhance light harvesting in tandem solar cells. Significantly, the control of the assembly of nanowire arrays may have a direct impact on bottom-up technologies of high anisotropy nanomaterials.

  5. The Human Telomere Sequence, (TTAGGG4, in the Absence and Presence of Cosolutes: A Spectroscopic Investigation

    Directory of Open Access Journals (Sweden)

    Vishal R. Sharma

    2014-01-01

    Full Text Available Historically, biophysical studies of nucleic acids have been carried out under near ideal conditions, i.e., low buffer concentration (e.g., 10 mM phosphate, pH 7, low ionic strength (e.g., 100 mM and, for optical studies, low concentrations of DNA (e.g., 1 × 10−6 M. Although valuable structural and thermodynamic data have come out of these studies, the conditions, for the most, part, are inadequate to simulate realistic cellular conditions. The increasing interest in studying biomolecules under more cellular-like conditions prompted us to investigate the effect of osmotic stress on the structural and thermodynamic properties of DNA oligomers containing the human telomere sequence (TTAGGG. Here, we report the characterization of (TTAGGG4 in potassium phosphate buffer with increasing percent PEG (polyethylene glycol or acetonitrile. In general, the presence of these cosolutes induces a conformational change from a unimolecular hybrid structure to a multimolecular parallel stranded structure. Hence, the structural change is accompanied with a change in the molecularity of quadruplex formation.

  6. Nuclear structure investigations of 84Sr and 86Sr using γ-ray spectroscopic methods

    Science.gov (United States)

    Duckwitz, H.; Petkov, P.; Thomas, T.; Ahn, T.; Blazhev, A.; Cooper, N.; Fransen, C.; Hinton, M.; Ilie, G.; Jolie, J.; Werner, V.

    2017-09-01

    To investigate the low-spin structure of 84Sr and 86Sr, two fusion-evaporation experiments using the (p,2n) reaction have been performed. The data have been evaluated in terms of γ-ray spectroscopy, i.e. the level scheme was built up, branching intensities were determined, nuclear state spin and parity assignments were made after γγ angular correlation analyses. The previously known level scheme information was extended. In addition, lifetimes were determined by means of the Doppler Shift Attenuation Method (DSAM). In 86Sr, a new method for lifetime determinations, the Spectral Difference Method (SDM), was applied for the first time. In cases where all necessary input variables were known, reduced transition strengths were calculated with Monte Carlo simulated probability density functions. It is stressed that linear error propagation for the calculated errors of reduced transition strengths is not universally applicable. As both nuclei lie in the vicinity of the N=50 neutron shell closure and on a possible proton subshell closure of the 2p3/2 orbital at Z=38, Nuclear Shell Model calculations for 84Sr, 86Sr, and 88Sr have been performed in the truncated (2p3/2, 1f5/2, 2p1/2, 1g9/2) model space for protons and neutrons with the empirical JUN45 residual interaction. The comparison between experimental results and theoretical predictions show a large degree of consistency.

  7. Spectroscopic investigation of the electronic structure of the chlorine molecule in the VUV

    Science.gov (United States)

    Moeller, Thomas; Jordan, Bernhard; Gürtler, Peter; Zimmerer, Georg; Haaks, Dieter; Le Calve, Jacques; Castex, Marie-Claude

    1983-04-01

    Vacuum ultraviolet absorption spectroscopy and fluorescence analysis under selective optical excitation have been combined to deduce the electronic structure of Cl 2. Between 73000 and 81000 cm -1 five bound electronic states could be analysed. Some of them are affected by pronounced Rydberg—valence mixing. Especially the 1 1∑ u+ state clearly yields a double-well structure which results from an avoided crossing between an ionic valence and a Rydberg state. The double-well structure is responsible for an irregular vibrational sequence between 73000 and 74500 cm -1 which either prevented an analysis in earlier investigations or lead to wrong assignments. The FC factors of the 1 1∑ u+ fluorescence with its bound—bound and bound—free contributions between ≈ 73000 and 50000 cm -1 are also severely affected by the double-well structure. The results are compared with the first ab initio calculations of the electronic structure of Cl 2. In general, excellent agreement is found.

  8. Investigation of the interaction of deltamethrin (DM) with human serum albumin by multi-spectroscopic method

    Science.gov (United States)

    Wang, Jiaman; Ma, Liang; Zhang, Yuhao; Jiang, Tao

    2017-02-01

    The interaction of Deltamethrin (DM) with human serum albumin (HSA) under the condition of simulating human blood pH environment (pH = 7.4) was investigated by fluorescence, UV-Vis absorbance and circular dichroism (CD) spectroscopy. It was shown that DM was a static quencher of HSA. The binding constants (Ka) are 3.598 × 104 L mol-1 (25 °C); the thermodynamic parameters (ΔH = -3.269 × 104 kJ mol-1, ΔS = -22.81 kJ mol-1 k-1, ΔG = -25889.8 kJ mol-1) obtained with the thermodynamic equation. The hydrogen bond and Vander Waals were the main driving force. The effect of DM on the conformation of HSA was observed by three-dimensional (3D) fluorescence and circular dichroism spectra, indicating that the interaction between DM and HSA was achieved through the binding of DM with the tryptophan and tyrosine residues of HSA. The study on the interaction of DM and Bovine Serum Albumin (BSA) was researched and compared. Difference exists in the interactions of with each of the serum albumins. We will verify and supplement that DM residue in animals and human metabolism, toxicology and other mechanisms are different.

  9. Non intrusive spectroscopic investigations of soot and unburnt hydrocarbons in combustion gases

    Science.gov (United States)

    Hilton, Moira; Arrigone, Giovanni M.; Miller, Michael N.

    1999-09-01

    Fourier Transform Infrared (FTIR) spectroscopy was used to investigate the IR spectral absorption of soot particles from a Palas smoke generator. A TSI Condensation Particle Counter was used to quantify the number of soot particles produced and this was related to the intensity of the IR absorption. The broad band IR absorption increases with soot particle count but quantitative measurements of total soot mass were not obtained because accurate size distributions of the particles were not available. A sample of gas turbine engine exhaust gas was analyzed by Gas Chromatography-Mass Spectroscopy to determine the primary constituent unburnt hydrocarbon (UHC) species. Their relative proportions were measured with a Flame Ionization Detector (FID). These species are predominantly unsaturated C2 to C6 hydrocarbons. The infrared absorption spectrum of the exhaust gas sample was compared with that of combustion products from a laboratory kerosene burner using a multipass White cell. These were also compared with reference spectra and IR spectra of UHCs obtained non-intrusively from gas turbine engine tests. There are IR spectral band shape differences indicating that the relative proportions of the constituent UHCs in gas turbine exhaust are different from those in a kerosene burner plume.

  10. Raman spectroscopic investigation of spinal cord injury in a rat model

    Science.gov (United States)

    Saxena, Tarun; Deng, Bin; Stelzner, Dennis; Hasenwinkel, Julie; Chaiken, Joseph

    2011-02-01

    Raman spectroscopy was used to study temporal molecular changes associated with spinal cord injury (SCI) in a rat model. Raman spectra of saline-perfused, injured, and healthy rat spinal cords were obtained and compared. Two injury models, a lateral hemisection and a moderate contusion were investigated. The net fluorescence and the Raman spectra showed clear differences between the injured and healthy spinal cords. Based on extensive histological and biochemical characterization of SCI available in the literature, these differences were hypothesized to be due to cell death, demyelination, and changes in the extracellular matrix composition, such as increased expression of proteoglycans and hyaluronic acid, at the site of injury where the glial scar forms. Further, analysis of difference spectra indicated the presence of carbonyl containing compounds, hypothesized to be products of lipid peroxidation and acid catalyzed hydrolysis of glycosaminoglycan moieties. These results compared well with in vitro experiments conducted on chondroitin sulfate sugars. Since the glial scar is thought to be a potent biochemical barrier to nerve regeneration, this observation suggests the possibility of using near infrared Raman spectroscopy to study injury progression and explore potential treatments ex vivo, and ultimately monitor potential remedial treatments within the spinal cord in vivo.

  11. Molecular structure and spectroscopic investigations combined with hypoglycemic/anticancer and docking studies of a new barbituric acid derivative

    Science.gov (United States)

    Barakat, Assem; Soliman, Saied M.; Elshaier, Yaseen A. M. M.; Ali, M.; Al-Majid, Abdullah Mohammed; Ghabbour, Hazem A.

    2017-04-01

    The one-pot synthesis reaction of barbituric acid derivative, 1,3-cyclohexandione, and 4-fluorobenzaldehyde in water mediated by NHEt2 as base afforded 4 with excellent yield. The synthesized compound was characterized by spectrophotometric tools as well as X-ray single crystal diffraction technique. The stability of the nine possible isomers of the synthesized compound was studied using the B3LYP method and 6-31G(d,p) basis set. The electronic and spectroscopic properties of the most stable isomer were predicted. The UV-Vis absorption spectrum displayed two bands at 203 and 257 nm in the solvent chloroform. The latter was calculated at 235.6 nm (f = 0.1995) in the gas phase due to H-2→L (42%) and H-1→L+2 (14%) excitations. In solution, using chloroform as a solvent, a slight bathochromic shift to 237.6 nm with an increase in the absorption intensity (f = 0.2898) was predicted. The molecular orbital energy level diagram of this transition band was characterized mainly by π-π* transitions. The 13C and 1H NMR chemical shifts correlated well with the experimental data. The correlations had higher correlation coefficients (R2) when solvent effects were considered. The atomic charges were calculated using natural population analysis and the charged regions were presented using a molecular electrostatic potential (MEP) map. The synthesized compound was examined as a hypoglycemic agent via inhibition of α-glucosidase and β-glucuronidase enzymes. Its inhibitory activity against α-glucosidase was 10 times greater than the inhibitory activity of the standard drug acarbose (IC50 77.9 ± 0.3 μM and 840 ± 1.73 μM, respectively). Moreover, the target compound was evaluated for anticancer activity against MCF-7, H460, 3T3, and Hela cell lines. It demonstrated inhibitory activity against the MCF-7 and H460 cell lines with IC50 5.80 ± 0.12 and 19.6 ± 0.5 μM, respectively, in comparison to doxorubicin. The docking study was performed using the OpenEye program.

  12. Raman spectroscopic and mass spectrometric investigations of the hydrogen isotopes and isotopically labelled methane

    Energy Technology Data Exchange (ETDEWEB)

    Jewett, J.R., Fluor Daniel Hanford

    1997-02-24

    Suitable analytical methods must be tested and developed for monitoring the individual process steps within the fuel cycle of a fusion reactor and for tritium accountability. The utility of laser-Raman spectroscopy accompanied by mass spectrometry with an Omegatron was investigated using the analysis of all hydrogen isotopes and isotopically labeled methanes as an example. The Omegatron is useful for analyzing all hydrogen isotopes mixed with the stable helium isotopes. The application of this mass spectrometer were demonstrated by analyzing mixtures of deuterated methanes. In addition, it was employed to study the radiochemical Witzbach exchange reaction between tritium and methanes. A laser-Raman spectrometer was designed for analysis of tritium-containing gases and was built from individual components. A tritium-compatible, metal-sealed Raman cuvette having windows with good optical properties and additional means for measuring the stray light was first used successfully in this work. The Raman spectra of the hydrogen isotopes were acquired in the pure rotation mode and in the rotation-vibration mode and were used for on. The deuterated methanes were measured by Raman spectroscopy, the wavenumbers determined were assigned to the corresponding vibrations, and the wavenumbers for the rotational fine-structure were summarized in tables. The fundamental Vibrations of the deuterated methanes produced Witzbach reactions were detected and assigned. The fundamental vibrations of the molecules were obtained with Raman spectroscopy for the first time in this work. The @-Raman spectrometer assembled is well suited for the analysis of tritium- containing gases and is practical in combination with mass spectrometry using an Omegatron, for studying gases used in fusion.

  13. Spectroscopic investigation on the interaction of some surfactant-cobalt(III) complexes with serum albumins

    Energy Technology Data Exchange (ETDEWEB)

    Vignesh, Gopalaswamy; Nehru, Selvan; Manojkumar, Yesaiyan; Arunachalam, Sankaralingam, E-mail: arunasurf@yahoo.com

    2014-01-15

    The interaction of HSA/BSA with single and double chain surfactant-cobalt(III) complexes, cis-[Co(phen){sub 2}(UA)Cl](ClO{sub 4}){sub 2}·2H{sub 2}O (1), cis-[Co(phen){sub 2}(UA){sub 2}](ClO{sub 4}){sub 3}·2H{sub 2}O (2), cis-[Co(en){sub 2}(UA)Cl](ClO{sub 4}){sub 2}·2H{sub 2}O (3), cis-[Co(en){sub 2}(UA){sub 2}](ClO{sub 4}){sub 3}·2H{sub 2}O (4), were investigated by steady state fluorescence, UV–vis absorption, synchronous, three dimensional fluorescence and circular dichroism spectroscopy. The results reveal that the quenching of HSA/BSA by all the four complexes takes place through static mechanism. The binding constant, binding sites and thermodymamic parameter were calculated. The results illustrate that the double chain surfactant-cobalt(III) complexes bind more strongly than the corresponding single chain complexes. The distance between donor (HSA/BSA) and acceptor (surfactant-cobalt(III) complexes) was obtained according to FRET. The results of synchronous, three dimensional and circular dichroism spectroscopy studies show that all the complexes caused considerable amount of conformational and some amount of environment changes in HSA/BSA. -- Highlights: • Binding of single and double chain surfactant-cobalt(III) complexes with serum albumins. • Hydrophobic attraction plays a major role in the binding process. • Binding induces considerable amount of conformational changes in the protein.

  14. Spectroscopic investigation of the charge dynamics of heavy ions penetrating solid and gaseous targets

    Energy Technology Data Exchange (ETDEWEB)

    Korostiy, S.

    2007-01-15

    This thesis presents the study of the slowing down process of fast heavy ions inside matter. In the framework of this research, the influence of the target density on the stopping process is investigated. Experiments on the interaction of {sup 48}Ca{sup 6+}-{sup 48}Ca{sup 10+} and {sup 26}Mg{sup 5+} ion beams with initial energies of 11.4 MeV/u and 5.9 MeV/u with solid and gaseous targets have been carried out. A novel diagnostic method, X-ray spectroscopy of K-shell projectile radiation, is used to determine the ion charge state in relation to its velocity during the penetration of fast heavy ions inside the stopping material. A spatially resolved analysis of the projectile and target radiation in solids is achieved for the first time. The application of low-density silica aerogels as stopping media provided a stretching of the ion stopping length by 20 - 100 times in comparison with solid quartz. The Doppler Effect observed on the projectile K-shell spectra is used to calculate the ion velocity in dependence on the ion penetration depth in the target material. A comparative analysis of K{sub {alpha}} spectra of fast heavy ions is performed in solid (silica aerogels) and gaseous targets (Ar and Ne gases) at the same ion energy. It is shown that the dominant role of collisions in dense matter leads to an increase of the effective ionization cross section at high ion velocity and suppression of the electron capture to the projectile ion excited states at low ion velocity. As a result, an increase of the ion charge state in dense matter is observed. The experimentally detected effects are interpreted with numerical calculations of the projectile population kinetics, which are in good agreement with measurements. (orig.)

  15. A spectroscopic investigation of the interaction between c-MYC DNA and tetrapyridinoporphyrazinatozinc(II).

    Science.gov (United States)

    Hassani, Leila; Fazeli, Zahra; Safaei, Elham; Rastegar, Hossein; Akbari, Minoo

    2014-06-01

    The c-MYC gene plays an important role in the regulation of cell proliferation and growth and it is overexpressed in a wide variety of human cancers. Around 90% of c-MYC transcription is controlled by the nuclease-hypersensitive element III1 (NHE III1), whose 27-nt purine-rich strand has the ability to form a G-quadruplex structure under physiological conditions. Therefore, c-MYC DNA is an attractive target for drug design, especially for cancer chemotherapy. Here, the interaction of water-soluble tetrapyridinoporphyrazinatozinc(II) with 27-nt G-rich strand (G/c-MYC), its equimolar mixture with the complementary sequence (GC/c-MYC) and related C-rich oligonucleotide (C/c-MYC) is investigated. Circular dichroism (CD) measurements of the G-rich 27-mer oligonucleotide in 150 mM KCl, pH 7 demonstrate a spectral signature consistent with parallel G-quadruplex DNA. Furthermore, the CD spectrum of the GC rich oligonucleotide shows characteristics of both duplex and quadruplex structures. Absorption spectroscopy implies that the complex binding of G/c-MYC and GC/c-MYC is a two-step process; in the first step, a very small red shift and hypochromicity and in the second step, a large red shift and hyperchromicity are observed in the Q band. Emission spectra of zinc porphyrazine are quenched upon addition of three types of DNA. According to the results of spectroscopy, it can be concluded the dominant binding mode is probably, outside binding and end stacking.

  16. Spectroscopic and bond-topological investigation of interstitial volatiles in beryl from Slovakia

    Science.gov (United States)

    Fridrichová, Jana; Bačík, Peter; Bizovská, Valéria; Libowitzky, Eugen; Škoda, Radek; Uher, Pavel; Ozdín, Daniel; Števko, Martin

    2016-06-01

    Nine beryl samples from Western Carpathians, Slovakia, were investigated by infrared and Raman spectroscopy and differential thermal analysis. Two types of water H2O I and H2O II were detected. Infrared spectroscopy proved the presence of water type I and II in the presence of alkali cations with several bands: (1) symmetric stretching vibration—ν1; (2) antisymmetric stretching mode—ν3; (3) bending vibration—ν2. The presence of singly and doubly coordinated type II water (IIs and IId) was confirmed by single-crystal IR spectroscopy. From Raman spectra a band at 3606 cm-1 was assigned to ν1 of water type I and the range of 3597-3600 cm-1 to water type II. The presence of doubly coordinating water indicates a relatively highly hydrated environment with the presence of alkali ions including Na as the dominant cation coordinated by H2O II. CO2 bands were detected only by single-crystal IR spectroscopy. Thermal analysis proved total water loss in the range of 1.4-2.0 wt% and three main dehydration events. Based on the study of bond-topological arrangements two molecules of H2O IId are each bound with two H···O1 bonds and one Na-OW bond with an angular distortion, and by releasing one H2O molecule more stable H2O IIs is produced. The H2O I molecule is bound only by two equivalent hydrogen bonds. The H2O IIs molecule with a Na-OW bond strength of 0.28 vu and two H···O1 bonds of 0.14 vu without any forced angular distortion is the most stable of all.

  17. Effect of hybrid oxidation on the titanium oxide layer's properties investigated by spectroscopic methods

    Science.gov (United States)

    Jasinski, J. J.; Kurpaska, L.; Lubas, M.; Lesniak, M.; Jasinski, J.; Sitarz, M.

    2016-12-01

    In this work the study of hybrid Ti Grade 2 during oxidation using FADT - fluidized bed atmospheric diffusive treatment and PVD - magnetron sputtering have been investigated. Additionally, the influence of the oxidation method on the change in the mechanism of oxygen transport to the substrate have been discussed (phenomenon responsible for the improvement of bioactivity). Presented method consists in forming the titanium surface layer saturated with oxygen due to the diffusion and deposition of a thin homogeneous oxide coating on the Ti surface. Discussed processes diminish the surface roughness and increase bio-compatibility of the surface, which results in easier hydroxyapatite cluster deposition. The diffusion process was conducted on Al2O3 fluidized bed, with air as the fluidizing factor at 913 K for 8 h. The deposition of the oxide coatings were carried out with magnetron sputtering, with the use of a TiO2 target at a pressure of 3 × 10-2 mbars and power of 350 W. To evaluate the effects of hybrid oxidation and to determine the mechanism of oxygen transport, the following research methods have been applied: spectroscopy (GDOS, SIMS, RS), microscopic methods (SEM-EDS, SEM-EBSD, TEM-EFTEM), X-ray tests (μ-XRD, GID). Obtained test results were used to identify the type of oxide coatings, to assess the thickness of the layers and to study the influence of crystallographic orientation on oxygen transport and concentration in the surface layer and in the oxide coating. It has been found that the formation of oxide coatings created by using the hybrid method (FADT + PVD leads to a change in oxygen concentration in the substrate due to introduced defects. This phenomenon is in opposition to the conventional methods such as: electrochemical or laser oxidation. In contrast, forming a tight homogeneous oxide coating on Ti surface improves the biocompatibility, which is particularly important in the context of biomedical applications.

  18. Structure and function of proteins investigated by crystallographic and spectroscopic time-resolved methods

    Science.gov (United States)

    Purwar, Namrta

    crystal. Time-resolved X-ray data collected at pH's of 4, 7 and 9 demonstrate that pH alters the kinetics of the PYP photocycle dramatically. At pH 4 the photocycle lasts almost one order of magnitude longer in time compared to pH 7. The final intermediate that accumulates at both pH 7 and pH 4 is absent at pH 9. Results from the dose- and the pH-dependent time-resolved crystallographic experiments show that it is imperative to carefully control the conditions under which time-resolved data are collected. With these considerations we collected a comprehensive time-series from nanoseconds to seconds at 14 different temperature settings from -40 °C to 70 °C. Results from time-resolved crystallography are corroborated by employing time-resolved absorption spectroscopy. For this, absorption spectra on crystals and solution are collected by a fast micro-spectrophotometer custom-designed in our lab. We identify kinetic phases of the PYP photocycle at all 14 temperature settings. Relaxation times associated with these phases are temperature-dependent and can be fit by the Van't Hoff-Arrhenius equation. Kinetic modeling yields entropy and enthalpy values at the barriers of the activation solely from the time-resolved crystallographic data. With this, we advance crystallography to a new frontier: the determination of free energy surfaces. Investigating enzymatic reactions can be challenging, because they are non-cyclic. After one turnover product must be washed away and substrate must be reloaded. A promising approach for routine application can be envisioned at the new 4th generation X-ray sources, such as X-ray free electron lasers (XFELs). With our results we set the scene to comprehensively investigate all kinds of enzymatic reactions with these instruments.

  19. Spectroscopic investigation of Dy3+:Lu2Si2O7 single crystal: A potential 589 nm laser medium

    Science.gov (United States)

    Huang, Jianhui; Chen, Yujin; Huang, Jianhua; Gong, Xinghong; Lin, Yanfu; Luo, Zundu; Huang, Yidong

    2017-10-01

    A trivalent dysprosium-doped Lu2Si2O7 single crystal was grown by the Czochralski method. Segregation coefficient of Dy3+ ion in the crystal is about 0.56. Spectroscopic properties of the crystal were investigated at room temperature. In particular, the polarized absorption spectra were analyzed using the Judd-Ofelt theory and the intensity parameters were determined. Then the spontaneous transition probabilities, branching ratios, and radiative lifetime related to the 4F9/2 multiplet were calculated. Emission cross-section for the 4F9/2 → 6H13/2 transition at 589 nm is up to 1.27 × 10-21 cm2 for E//Y polarization. Thermal conductivity of the crystal was measured to be 9.46 Wm-1K-1 at room temperature. The experimental results show that the Dy3+:Lu2Si2O7 crystal is a promising gain medium for solid state 589 nm laser.

  20. Investigation of role of silver nanoparticles on spectroscopic properties of biologically active coumarin dyes 4PTMBC and 1IPMBC.

    Science.gov (United States)

    Raghavendra, U P; Basanagouda, Mahantesha; Thipperudrappa, J

    2015-01-01

    The role of silver nanoparticles on spectroscopic properties of biologically active coumarin dyes 4-p-tolyloxymethyl-benzo[h]coumarin (4PTMBC) and 1-(4-iodophenoxymethyl)-benzo[f]coumarin (1IPMBC) has been investigated using absorption and fluorescence spectroscopy. Silver nanoparticles are synthesized by chemical reduction method and the estimated size by Mie theory is 12 nm. The absorption spectral changes of dyes in the presence of silver nanoparticles suggest their possible interaction with silver nanoparticles. The apparent association constants of the interaction are estimated using Benesi-Hildebrand model. Fluorescence quenching has been observed in both the dyes with the addition of silver nanoparticles. The Stern-Volmer plots of fluorescence quenching are found to be nonlinear showing positive deviation. The magnitudes of quenching rate parameter and fluorescence lifetime measurements indicate the presence of both collisional and static quenching mechanisms. The binding constants and the number of binding sites for the static type of quenching have been estimated from the fluorescence data. The role of diffusion, energy transfer and electron transfer processes in fluorescence quenching mechanism has been discussed.

  1. Investigation of the mouse cerebellum using STIM and {mu}-PIXE spectrometric and FTIR spectroscopic mapping and imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hackett, M.J. [School of Chemistry, University of Sydney, NSW 2006 (Australia); Siegele, R., E-mail: rns@ansto.gov.au [Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Lucas Heights NSW 2234 (Australia); El-Assaad, F. [Vascular Immunology Unit, Bosch Institute and School of Medical Sciences, University of Sydney, NSW 2006 (Australia); McQuillan, J.A. [Molecular Immunopathology Unit, Bosch Institute and School of Medical Sciences, University of Sydney, NSW 2006 (Australia); Aitken, J.B.; Carter, E.A. [School of Chemistry, University of Sydney, NSW 2006 (Australia); Grau, G.E. [Vascular Immunology Unit, Bosch Institute and School of Medical Sciences, The University of Sydney, NSW 2006 (Australia); Hunt, N.H. [Molecular Immunopathology Unit, Bosch Institute and School of Medical Sciences, The University of Sydney, NSW 2006 (Australia); Cohen, D. [Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Lucas Heights NSW 2234 (Australia); Lay, P.A. [School of Chemistry, The University of Sydney, NSW 2006 (Australia)

    2011-10-15

    The cerebral biochemistry associated with the development of many neurological diseases remains poorly understood. In particular, incomplete understanding of the mechanisms through which vascular inflammation manifests in tissue damage and altered brain function is a significant hindrance to the development of improved patient therapies. To this extent, a combination of spectrometric/spectroscopic mapping/imaging methods with an inherent ability to provide a wealth of biochemical and physical information have been investigated to understand further the pathogenesis of brain disease. In this study, proton-induced X-ray emission (PIXE) mapping was combined with scanning transmission ion microscopy (STIM) mapping and Fourier-transform infrared (FTIR) imaging of the same tissue sample to study directly the composition of the murine (mouse) cerebellum. The combination of the elemental, density and molecular information provided by these techniques enabled differentiation between four specific tissue types within the murine cerebellum (grey matter, white matter, molecular layer and micro blood vessels). The results presented are complementary, multi-technique measurements of the same tissue sample. They show elemental, density and molecular differences among the different tissue types.

  2. An investigation of the photophysical properties of minor groove bound and intercalated DAPI through quantum-mechanical and spectroscopic tools.

    Science.gov (United States)

    Biancardi, Alessandro; Biver, Tarita; Secco, Fernando; Mennucci, Benedetta

    2013-04-07

    The fluorescent probe 4',6-diamidino-2-phenylindole (DAPI) is a dye known to interact with polynucleotides in a non-univocal manner, both intercalation and minor groove binding modes being possible, and to specifically change its photophysical properties according to the different environments. To investigate this behavior, quantum-mechanical calculations using time-dependent density functional theory (TDDFT), coupled with polarizable continuum and/or atomistic models, were performed in combination with spectroscopic measurements of the probe in the different environments, ranging from a homogeneous solution to the minor groove or intercalation pockets of double stranded nucleic acids. According to our simulation, the electronic transition involves a displacement of the electron charge towards the external amidine groups and this feature makes the absorption energies very environment-sensitive while a much smaller sensitivity is seen in the fluorescence energies. Moreover, the calculations show that the DAPI molecule, when minor groove bound to the nucleic acid, presents both a reduced geometrical flexibility because of the rigid DNA pocket and a reduced polarization due to the very "apolar" microenvironment. All these effects can be used to better understand the observed enhancement of the fluorescence, which makes it an excellent marker for DNA.

  3. Computational Chemistry Meets Experiments for Explaining the Behavior of Bibenzyl: A Thermochemical and Spectroscopic (Infrared, Raman, and NMR) Investigation.

    Science.gov (United States)

    Latouche, Camille; Barone, Vincenzo

    2014-12-09

    The structure, conformational behavior, and spectroscopic parameters of bibenzyl have been investigated by a computational protocol including proper treatment of anharmonic and hindered rotor contributions. Conventional hybrid functionals overstabilize the anti conformer while low-order post-Hartree-Fock (MP2) approaches strongly favor the gauche conformer. However, inclusion of semiempirical dispersion effects in density functionals or coupled cluster post-Hartree-Fock models agree in forecasting the simultaneous presence of both conformers in the gas phase with a slightly larger stability (0.7 kcal·mol(-1)) of the gauche conformer. Addition of thermal and entropic effects finally leads to very close Gibbs free energies for both conformers and, thus, to a slight preference for the gauche form due to statistical factors (2 vs 1). The situation remains essentially the same in solution. On these grounds, perturbative vibrational computations including both electrical and mechanical anharmonicities lead to IR and Raman spectra in remarkable agreement with experiment. Full assignment of the IR spectra explains the presence of peaks from gauche or anti conformers. Comparison between computed and experimental Raman spectra confirms that both conformers are present in liquid phase, whereas the anti conformer seems to be preponderant in the solid state. Also computed NMR parameters are in good agreement with experiment.

  4. Microwave spectroscopic and theoretical investigations of the strongly hydrogen bonded hexafluoroisopropanol···water complex.

    Science.gov (United States)

    Shahi, A; Arunan, E

    2015-10-14

    This paper reports microwave spectroscopic and theoretical investigations on the interaction of water with hexafluoroisopropanol (HFIP). The HFIP monomer can exist in two conformations, antiperiplanar (AP) and synclinical (SC). The former is about 5 kJ mol(-1) more stable than the latter. Theoretical calculations predicted three potential minima for the complex, two having AP and one having SC conformations. Though, the binding energy for the HFIP(SC)···H2O turned out to be larger than that for the other two conformers having HFIP in the AP form, the global minimum for the complex in the potential energy hypersurface had HFIP in the AP form. Experimental rotational constants for four isotopologues measured using a pulsed nozzle Fourier transform microwave spectrometer, correspond to the global minimum in the potential energy hypersurface. The structural parameters and the internal dynamics of the complex could be determined from the rotational spectra of the four isotopologues. The global minimum has the HFIP(AP) as a hydrogen bond donor forming a strong hydrogen bond with H2O. To characterize the strength of the bonding and to probe the other interactions within the complex, atoms in molecules, non-covalent interaction index and natural bond orbital theoretical analyses have been performed.

  5. Investigation of the behavior of HSA upon binding to amlodipine and propranolol: Spectroscopic and molecular modeling approaches

    Science.gov (United States)

    Housaindokht, Mohammad Reza; Rouhbakhsh Zaeri, Zeinab; Bahrololoom, Mahmood; Chamani, Jamshid; Bozorgmehr, Mohammad Reza

    2012-01-01

    The interaction between human serum albumin (HSA) and two drugs - amlodipine and propranolol - was investigated using fluorescence, UV absorption and circular dichroism (CD) spectroscopy. In addition, the binding site was established by applying molecular modeling technique. Fluorescence data suggest that amlodipine will quench the intrinsic fluorescence of HSA; whereas propranolol enhances the fluorescence of HSA. The binding constants for the interaction of amlodipine and propranolol with HSA were found to be 3.63 × 10 5 M -1 and 2.29 × 10 4 M -1, respectively. The percentage of secondary structure feature of each one of the HSA-bound drugs, i.e. the α-helix content, was estimated empirically by circular dichroism. The results indicated that amlodipine causes an increase, and that propranolol leads to a decrease in α-helix content of HSA. The spectroscopic analysis indicates that the binding mechanisms of the two drugs are different from each other. The data obtained by the molecular modeling study indicated that these drugs bind, with different affinity, to different sites located in subdomain IIA and IIIA.

  6. Raman spectroscopic investigation of the chemopreventive response of naringenin and its nanoparticles in DMBA-induced oral carcinogenesis

    Science.gov (United States)

    Krishnakumar, N.; Sulfikkarali, N. K.; Manoharan, S.; Venkatachalam, P.

    2013-11-01

    Raman spectroscopy is a vibrational spectroscopic technique that can be used to optically probe the biomolecular changes associated with tumor progression. The aim of the present study is to investigate the biomolecular changes in chemopreventive response of prepared naringenin-loaded nanoparticles (NARNPs) relative to efficacy of free naringenin (NAR) during 7,12-dimethyl benz(a)anthracene (DMBA)-induced oral carcinogenesis by Fourier Transform Raman (FT-Raman) spectroscopy. Oral squamous cell carcinoma (OSCC) was developed in the buccal pouch of golden Syrian hamsters by painting with 0.5% DMBA in liquid paraffin three times a week for 14 weeks. Raman spectra differed significantly between the control and tumor tissues, with tumors showing higher percentage signals for nucleic acids, phenylalanine and tryptophan and a lower in the percentage of phospholipids. Moreover, oral administration of free NAR and NARNPs significantly increased phospholipids and decreased the levels of tryptophan, phenylalanine and nucleic acid contents. On a comparative basis, NARNPs was found to have a more potent antitumor effect than free NAR in completely preventing the formation of squamous cell carcinoma and in improving the biochemical status to a normal range in DMBA-induced oral carcinogenesis. The present study further suggest that Raman spectroscopy could be a valuable tool for rapid and sensitive detection of specific biomolecular changes in response to chemopreventive agents.

  7. Spectroscopic investigations of Np(V/VI) redox speciation in hyperalkaline TMA-(OH, Cl) solutions

    Energy Technology Data Exchange (ETDEWEB)

    Gaona, X.; Dardenne, K.; Liu, X.; Rothe, J.; Denecke, M.A.; Altmaier, M. [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany). Inst. fuer Nukleare Entsorgung; Tits, J.; Wieland, E. [Paul Scherrer Institut (PSI), Villigen (Switzerland). Lab. for Waste Management

    2012-07-01

    The redox chemistry of Np(V/VI) was investigated in {proportional_to} 0.6 M tetramethylammonium hydroxide/chloride (TMA-(OH, Cl)) solutions with 9 {<=} -log [H{sup +}] {<=} 13.5. Redox conditions were defined by the absence or presence of ClO{sup -} as oxidizing agent (Na-salt, 5 x 10{sup -3} M and 5 x 10{sup -2} M). The high total Np concentration ([Np]{sub tot} {proportional_to} 2 x 10{sup -3} M) led to the precipitation of solid phases in some of the samples. The carbonate concentration (as impurity of TMA-OH) was 2-3 x 10{sup -3} M. UV-vis/NIR spectra obtained from the supernatant in TMA-(OH, Cl) solutions and absence of ClO{sup -} showed clear Np(V) features, identified as NpO{sub 2}{sup +}, NpO{sub 2}CO{sub 3}{sup -} and (NpO{sub 2}){sub x}(CO{sub 3}){sub y}(OH){sub z}{sup x-2y-z}. No NIR features were observed within 800 nm {<=} {lambda} {<=} 1300 nm for samples with ClO{sup -}. XANES edge energies and features of these samples confirmed the predominance of Np(V) in the absence of ClO{sup -} and Np(VI) in the presence of ClO{sup -}, by comparison to XANES reference spectra of Np(III/IV/V/VI) prepared within the present work by in-situ electrolysis. A similar Np redox distribution was observed for the solid phases based on XANES and EXAFS measurements. EXAFS spectra indicative of Np{sup V}O{sub 2}OH(s) and Np{sup VI}O{sub 3} . xH{sub 2}O(s) were obtained for samples in absence and presence of ClO{sup -}, respectively. The formation of a Na-Np(VI) phase in 5 x 10{sup -2} M ClO{sup -} and -log [H{sup +}] {proportional_to} 12 was also indicated from the EXAFS, chemical analysis and SEM-EDS. These results indicate that Np(VI) aqueous species and solid compounds prevail far below the oxidation border of water in alkaline solutions and also far below the E{sub H} border calculated with the current NEA data selection [1]. These observations are further supported by correlations of literature thermodynamic data for actinides (U, Np, Pu and Am), which predict the

  8. Cleaning spectroscopic samples of stars in nearby dwarf galaxies: The use of the nIR MgI line to weed out Milky Way contaminants

    CERN Document Server

    Battaglia, Giuseppina

    2012-01-01

    Dwarf galaxies provide insights on the processes of star formation and chemical enrichment at the low end of the galaxy mass function, as well as on the clustering of dark matter on small scales. In studies of Local Group dwarf galaxies, spectroscopic samples of individual stars are used to derive the internal kinematics and abundance properties of these galaxies. It is therefore important to clean these samples from Milky Way stars, not related to the dwarf galaxy, since they can contaminate the analysis of the properties of these objects. Here we introduce a new diagnostic for separating Milky Way contaminant stars -- that mainly constitute of dwarf stars -- and red giant branch stars targeted in dwarf galaxies. As discriminator we use the trends in the equivalent width of the nIR MgI line at 8806.8 \\AA\\ as a function of the equivalent width of CaII triplet lines. This method is particularly useful for works dealing with multi-object intermediate resolution spectroscopy focusing in the region of the nIR CaI...

  9. Spectroscopic line parameters of 12CH4 for atmospheric composition retrievals in the 4300-4500 cm-1 region

    Science.gov (United States)

    Hashemi, R.; Predoi-Cross, A.; Nikitin, A. V.; Tyuterev, Vl. G.; Sung, K.; Smith, M. A. H.; Malathy Devi, V.

    2017-01-01

    Due to the importance of methane as a trace atmospheric gas and a greenhouse gas, we have carried out a precise line-shape study to obtain the CH4-CH4 and CH4-air half-width coefficients, CH4-CH4 and CH4-air shift coefficients and off-diagonal relaxation matrix element coefficients for methane transitions in the spectral range known as the "methane Octad". In addition, the associated temperature dependences of these coefficients have been measured in the 4300-4500 cm-1 region of the Octad. The high signal to noise ratio spectra of pure methane and of dilute mixtures of methane in dry air with high resolution have been recorded at temperatures from 148 K to room temperature using the Bruker IFS 125 HR Fourier transform spectrometer (FTS) at the Jet Propulsion Laboratory, Pasadena, California. The analysis of spectra was done using a multispectrum non-linear least-squares curve fitting technique. Theoretical calculations have been performed and the results are compared with the previously published line positions, intensities and with the line parameters available in the GEISA and HITRAN2012 databases.

  10. A luminescence line-narrowing spectroscopic study of the uranium(VI) interaction with cementitious materials and titanium dioxide.

    Science.gov (United States)

    Tits, Jan; Walther, Clemens; Stumpf, Thorsten; Macé, Nathalie; Wieland, Erich

    2015-01-21

    Non-selective luminescence spectroscopy and luminescence line-narrowing spectroscopy were used to study the retention of UO2(2+) on titanium dioxide (TiO2), synthetic calcium silicate hydrate (C-S-H) phases and hardened cement paste (HCP). Non-selective luminescence spectra showed strong inhomogeneous line broadening resulting from a strongly disordered UO2(2+) bonding environment. This problem was largely overcome by using luminescence line-narrowing spectroscopy. This technique allowed unambiguous identification of three different types of UO2(2+) sorbed species on C-S-H phases and HCP. Comparison with spectra of UO2(2+) sorbed onto TiO2 further allowed these species to be assigned to a surface complex, an incorporated species and an uranate-like surface precipitate. This information provides the basis for mechanistic models describing the UO2(2+) sorption onto C-S-H phases and HCP and the assessment of the mobility of this radionuclide in a deep geological repository for low and intermediate level radioactive waste (L/ILW) as this kind of waste is often solidified with cement prior to storage.

  11. Laboratory Investigation on Lightning Flashes to High Voltage Transmission Lines%Laboratory Investigation on Lightning Flashes to High Voltage Transmission Lines

    Institute of Scientific and Technical Information of China (English)

    Thongchai Disyadej; Stanislaw Grzybowski

    2011-01-01

    This paper presents an investigation on the attractive width of high voltage transmission lines to lightning strikes. In order to design the optimal lightning protection, the estimated number of lightning flashes on the line, which is based on its attractive width, needs to be determined. The investigation was performed using experiments with model tests at the Mississippi State University High Voltage Laboratory. For laboratory experiments, a total of 2,100 negative and positive switching impulse voltages were applied to transmission line models from a conducting rod, which represented a lightning downward leader. Different tested models of transmission lines on a scale of 1:100 were used. The effects of overhead ground wires, phase conductors, tower structures, and the magnitude and polarity of lightning strokes were also studied. The attractive width increased gradually with the height of overhead ground wires and towers as well as the magnitude of the lightning stroke current. Impulse polarity had an impact on the at- tractive width, and the attractive width for negative polarity was larger than that {or positive polarity. The taller tower had more effect on flash distribution to transmission lines than the shorter one. The experimental results agree with the actual transmission line observations published in literature. The new expressions for the attractive width of transmission lines, based on the experimental results, were established. The accurate estimation of the attractive width can help electric power utilities plan transmission systems reliably and economically. The detailed description of the back- ground problem, proposed method, experimental results, and analysis are presented in this paper.

  12. An Investigation of Students' Views about Enzymes by Fortune Lines Technique

    Science.gov (United States)

    Özarslan, Murat; Çetin, Gülcan

    2014-01-01

    This study aimed to investigate ninth grade students' views about enzymes using fortune lines technique and to obtain the students' views about fortune lines technique. Participants were 38 ninth grade students in a Technique Vocational Girls High School in the city of Kocaeli, Turkey. After instruction of subject of enzymes, the participants were…

  13. An Investigation of Students' Views about Enzymes by Fortune Lines Technique

    Science.gov (United States)

    Özarslan, Murat; Çetin, Gülcan

    2014-01-01

    This study aimed to investigate ninth grade students' views about enzymes using fortune lines technique and to obtain the students' views about fortune lines technique. Participants were 38 ninth grade students in a Technique Vocational Girls High School in the city of Kocaeli, Turkey. After instruction of subject of enzymes, the…

  14. An Investigation of Students' Views about Enzymes by Fortune Lines Technique

    Science.gov (United States)

    Özarslan, Murat; Çetin, Gülcan

    2014-01-01

    This study aimed to investigate ninth grade students' views about enzymes using fortune lines technique and to obtain the students' views about fortune lines technique. Participants were 38 ninth grade students in a Technique Vocational Girls High School in the city of Kocaeli, Turkey. After instruction of subject of enzymes, the participants were…

  15. a Combined Gigahertz and Terahertz Synchrotron-Based Fourier Transform Infrared Spectroscopic Investigation of Ortho-D

    Science.gov (United States)

    Albert, Sieghard; Chen, Ziqiu; Fábri, Csaba; Prentner, Robert; Quack, Martin; Zindel, Daniel

    2017-06-01

    Tunneling switching is a fundamental phenomenon of interest in molecular quantum dynamics including also chiral molecules and parity violation. Deuterated phenols have been identified as prototypical achrial candidates. We report the high resolution spectroscopic investigation of the ortho-D-phenol in the GHz and THz ranges following our recent discovery of tunneling switching in its isotopomer meta-D-phenol. Here we report new results on ortho-D-phenol.The pure rotational spectra were recorded in the range of 72-117 GHz and assigned to the syn- and anti- structures in the ground and the first excited torsional states. Specific torsional states were assigned based on a comparison of experimental rotational constants with the quasiadiabatic channel reaction path Hamiltonian (RPH) calculations. The torsional fundamental at 308 cm^{-1} and the first hot band at 275 cm^{-1} were subsequently assigned. The analyses of pure rotational and rovibrational spectra shall be discussed in detail in relation to possible tunneling switching. M. Quack , Fundamental Symmetries and Symmetry Violations from High-resolution Spectroscopy, Handbook of High Resolution Spectroscopy, M. Quack and F. Merkt eds.,John Wiley & Sons Ltd, Chichester, New York, 2001, vol. 1, ch. 18, pp. 659-722. R. Prentner, M. Quack, J. Stohner and M. Willeke, J. Phys. Chem. A 119, 12805-12822 (2015). S. Albert, Z. Chen, C. Fábri, R. Prentner M. Quack and D. Zindel, paper at this meeting. S. Albert, Ph. Lerch, R. Prentner and M. Quack, Angew. Chem. Int. Ed. 52, 346-349 (2013). S. Albert, Z. Chen, C. Fábri,P. Lerch, R. Prentner and M. Quack, Mol.Phys. 114, 2751-2768 (2016) and 71st International Symposium on Molecular Spectroscopy, Urbana-Champaign, USA, June 20-24, Talk FE04 (2016).

  16. Linear and nonlinear optical investigations of nano-scale Si-doped ZnO thin films: spectroscopic approach

    Science.gov (United States)

    Jilani, Asim; Abdel-wahab, M. Sh.; Zahran, H. Y.; Yahia, I. S.; Al-Ghamdi, Attieh A.

    2016-09-01

    Pure and Si-doped ZnO (SZO) thin films at different concentration of Si (1.9 and 2.4 wt%) were deposited on highly cleaned glass substrate by radio frequency (DC/RF) magnetron sputtering. The morphological and structural investigations have been performed by atomic force electron microscope (AFM) and X-ray diffraction (XRD). The X-ray photoelectron spectroscopy was employed to study the composition and the change in the chemical state of Si-doped ZnO thin films. The optical observations like transmittance, energy band gap, extinction coefficient, refractive index, dielectric loss of pure and Si-doped ZnO thin films have been calculated. The linear optical susceptibility, nonlinear refractive index, and nonlinear optical susceptibility were also studied by the spectroscopic approach rather than conventional Z-scan method. The energy gap of Si-doped ZnO thin films was found to increase as compared to pure ZnO thin films. The crystallinity of the ZnO thin films was effected by the Si doping. The O1s spectra in pure and Si-doped ZnO revealed the bound between O-2 and Zn+2 ions and reduction in the surface oxygen with the Si doping. The chemical state analysis of Si 2p showed the conversation of Si to SiOx and SiO2. The increase in the first-order linear optical susceptibility χ (1) and third-order nonlinear optical susceptibility χ (3) was observed with the Si doping. The nonlinear studies gave some details about the applications of metal oxides in nonlinear optical devices. In short, this study showed that Si doping through sputtering has effected on the structural, surface and optical properties of ZnO thin films which could be quite useful for advanced applications such as metal-oxide-based optical devices.

  17. Spectroscopic investigation of the interaction between G-quadruplex of KRAS promoter sequence and three isoquinoline alkaloids

    Science.gov (United States)

    Wen, Li-Na; Xie, Meng-Xia

    2017-01-01

    KRAS promoter can form G-quadruplex structure and regulate gene transcription. The drugs which can bind with G-quadruplex of KRAS promoter may be potential remedy for treatment of cancers associated with KRAS mutation. The interaction mechanism between the G-quadruplex of KRAS promoter and three isoquinoline alkaloids (jatrorrhizine, berberine and sanguinarine) has been investigated by UV-visible, fluorescence and circular dichroism spectroscopic methods. The results showed that the three alkaloids can form complexes with G-quadruplex KRAS promoter with the molecular ratio of 1:1, and the binding constants were (0.90 ± 0.16) × 106 L mol- 1, (0.93 ± 0.21) × 106 L mol- 1 and (1.16 ± 0.45) × 106 L mol- 1 for jatrorrhizine, berberine and sanguinarine. The absorption spectra, KI quenching and fluorescence anisotropy and polarization studies suggested jatrorrhizine and berberine interacted with G-quadruplex by not only end-stacking binding mode but also grooves or loops binding mode, while sanguinarine by end-stacking binding mode. Sanguinarine was more beneficial to maintain the stability and parallel conformation of KRAS promoter G-quadruplex. MTT assay was performed to evaluate antiproliferation effects of the three isoquinoline alkaloids on SW620 cells, and the antiproliferation effects of the three alkaloids were sanguinarine > berberine > jatrorrhizine. All the three alkaloids can bind with KRAS promoter G-quadruplex, and sanguinarine had the better binding property and antiproliferation effects on SW620 cells. The results obtained are meaningful to explore potential reagents targeting the parallel G-quadruplex structure of KRAS promoter for gene theraphy of colorectal carcinomas.

  18. Molecular interaction of 2,4-diacetylphloroglucinol (DAPG) with human serum albumin (HSA): The spectroscopic, calorimetric and computational investigation

    Science.gov (United States)

    Pragna Lakshmi, T.; Mondal, Moumita; Ramadas, Krishna; Natarajan, Sakthivel

    2017-08-01

    Drug molecule interaction with human serum albumin (HSA) affects the distribution and elimination of the drug. The compound, 2,4-diacetylphloroglucinol (DAPG) has been known for its antimicrobial, antiviral, antihelminthic and anticancer properties. However, its interaction with HSA is not yet reported. In this study, the interaction between HSA and DAPG was investigated through steady-state fluorescence, time-resolved fluorescence (TRF), circular dichroism (CD), Fourier transform infrared (FT-IR) spectroscopy, isothermal titration calorimetry (ITC), molecular docking and molecular dynamics simulation (MDS). Fluorescence spectroscopy results showed the strong quenching of intrinsic fluorescence of HSA due to interaction with DAPG, through dynamic quenching mechanism. The compound bound to HSA with reversible and moderate affinity which explained its easy diffusion from circulatory system to target tissue. The thermodynamic parameters from fluorescence spectroscopic data clearly revealed the contribution of hydrophobic forces but, the role of hydrogen bonds was not negligible according to the ITC studies. The interaction was exothermic and spontaneous in nature. Binding with DAPG reduced the helical content of protein suggesting the unfolding of HSA. Site marker fluorescence experiments revealed the change in binding constant of DAPG in the presence of site I (warfarin) but not site II marker (ibuprofen) which confirmed that the DAPG bound to site I. ITC experiments also supported this as site I marker could not bind to HSA-DAPG complex while site II marker was accommodated in the complex. In silico studies further showed the lowest binding affinity and more stability of DAPG in site I than in site II. Thus the data presented in this study confirms the binding of DAPG to the site I of HSA which may help in further understanding of pharmacokinetic properties of DAPG.

  19. A Large-scale Spectroscopic Survey of Methanol and OH Line Emission from the Galactic Center: Observations and Data

    Science.gov (United States)

    Cotton, W. D.; Yusef-Zadeh, F.

    2016-11-01

    Class I methanol masers are collisionally pumped and are generally correlated with outflows in star-forming sites in the Galaxy. Using the Very Large Array in its A-array configuration, we present a spectral line survey to identify methanol J={4}-1\\to {3}0E emission at 36.169 GHz. Over 900 pointings were used to cover a region 66‧ × 13‧ along the inner Galactic plane. A shallow survey of OH at 1612, 1665, 1667, and 1720 MHz was also carried out over the area covered by our methanol survey. We provide a catalog of 2240 methanol masers with narrow line-widths of ˜1 km s-1, spatial resolutions of ˜ 0\\buildrel{\\prime\\prime}\\over{.} 14× 0\\buildrel{\\prime\\prime}\\over{.} 05, and rms noises ˜20 mJy beam-1 per channel. Lower limits on the brightness temperature range from 27,000 to 10,000,000 K, showing that the emission is of non-thermal origin. We also provide a list of 23 OH (1612), 14 OH (1665), 5 OH (1667), and 5 OH (1720 MHz) masers. The origin of such a large number of methanol masers is not clear. Many methanol masers appear to be associated with infrared dark clouds, though it appears unlikely that the entire population of these masers traces the early phase of star formation in the Galactic center.

  20. Investigation of Wear Behaviour of Sewn Assemblies of Viscose Linings with Different Treatment

    Directory of Open Access Journals (Sweden)

    Dainora BAČKAUSKAITĖ

    2011-07-01

    Full Text Available Different types of chemical treatment of textile are widely applied in advanced textile. Finishing of textile can provide additional functional properties for products or/and to improve the appearance of final product as well as to improve their mechanical properties. In this research the influence of the industrial treatment of viscose linings on the parameters of fabric surface friction, on fabric surface appearance as well as on the slippage resistance of yarns at a seam was investigated. Raw, dyed, dyed and softened, dyed and non-slip finished plain weaved linings were investigated. The slippage resistance of yarns at a seam in woven fabrics was evaluated according to standard EN ISO 13936-1:2004. The friction was investigated according to the standard DIN 53375 in a fabric-fabric friction pair. Surface of raw, dyed, dyed and softened viscose lining was investigated using SEM. The obtained results have shown that the friction parameters as well as the parameters of seam slippage resistance of dyed or dyed and softened fabrics were higher than the ones of raw fabric. The highest differences in those parameters were obtained for lining that was dyed and treated with non-slip finishing. That type of finishing influenced the break of lining yarns without typical to the other investigated linings slipping near a stitching line.http://dx.doi.org/10.5755/j01.ms.17.2.485

  1. Geotechnical Investigation : Farmers High Line Canal realignment at Two Ponds Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — As requested by the Farmers High Line (FHL) Board of Director's, Tetra Tech RMC has prepared aGeo technical Investigation Report for the proposed realignment of the...

  2. Laserspectroscopic investigations of the lithium- D-lines in magnetic fields

    Science.gov (United States)

    Windholz, L.; Jäger, H.; Musso, M.; Zerza, G.

    1990-03-01

    Laser-atomic-beam investigations of the lithium D 1- and D 2-line in magnetic fields were performed using cw-laser excitation and fluorescence detection. For both isotopes6Li and7Li, the hyperfine splittings of the ground level 22 S 1/2 and the upper level of the D 1-line, 22 P 1/2, as well as the isotopic shifts of the D 1- and the D 2-line were determined from the registrations without field. In magnetic fields, Zeeman- and Paschen-Back-effects of the lines were studied. Using the Zeeman pattern of the D 1-line for a calibration of the field strength, values for the hyperfine constants A and B of the 22 P 3/2-level of7Li could be derived from the Zeeman pattern of the D 2-line.

  3. Micro-spectroscopic investigation of valence change processes in resistive switching SrTiO{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Koehl, Annemarie

    2014-05-15

    Due to physical limitations of the currently used flash memory in terms of writing speed and scalability, new concepts for data storage attract great interest. A possible alternative with promising characteristics are so-called ''Resistive Random Access Memories'' (ReRAM). These memory devices are based on the resistive switching effect where the electrical resistance of a metal-insulator-metal (MIM) structure can be switched reversibly by a current or voltage pulse. Although this effect attracted wide scientific as well as commercial interest, up to now the it is not fully understood on a microscopic scale. Consequently, in this work the chemical and physical modifications caused by the resistive switching process are studied by spectroscopic techniques. As most switching models predict a strongly localized rather than a homogeneous effect, advanced micro-spectroscopy techniques are employed where additionally the lateral structure of the sample is imaged. In this work Fe-doped SrTiO{sub 3} films are used as model material due to the thorough understanding of their defect chemistry. The epitaxial thin films are prepared by pulsed laser deposition. In a first approach, transmission X-ray microscopy is employed to study the bulk properties of ReRAM devices. At first, a new procedure for sample preparation based on a selective etching process is developed in order to realize photon-transparent samples. Investigations of switched devices reveal a significant contribution of Ti{sup 3+} states within growth defects. In contrast to the indirect evidence in previous studies, this observation directly confirms that the resistance change is based on a local redox-process. The localization of the switching process within the growth defects is explained by a self-accelerating process due to Joule heating within the pre-reduced defects. In a second approach, after removal of the top electrode the chemical and electronic structure of the former interface

  4. The study of polymers in geometrically confined states by the thermal analysis, the spectroscopic study, and the morphological investigation

    Science.gov (United States)

    Lu, Xiaolin

    2005-07-01

    This thesis focuses on the study of the different geometrically confined states of polyacrylamide (PAL) in bulk film, single chain globules, and thin films. The thermal analysis, the spectroscopic study, and the morphological investigation were carried out. The main contribution of this thesis is that we have acquired a better understanding about the glass transition (T g) behavior of polymers. Although the glass transition is a well known phenomenon for liquids with strong covalently bonded structures, and is especially noteworthy for amorphous polymers, understanding the glass transition still remains one of the most intriguing puzzles in condensed matter physics at present. The solution of the glass transition puzzle will ultimately influence different fields in polymer science, particularly biophysics and biochemistry. Our approach to this complicated assignment, the glass transition phenomenon, is to examine the glass transition behavior of polymer chains in 3 dimensional confinement for single molecular single chain globules, 1 dimensional confinement for polymer thin films, and 0 dimensional confinement for bulk state polymer. We found that the glass transition temperature of a polymer depends on several factors, such as the inter-chain interlock entanglement, the inter-chain molecular interactions, the intra-chain cohesional entanglement, and the local chain orientation and conformational entropy. These factors have been systematically investigated by carefully preparing the polymer samples in different confined states. The main conclusion is that, although the glass transition is a non-equilibrium dynamic property, the true glass transition can be reached when polymer chains are free of the inter-chain entanglement. A better example is illustrated, in this thesis, of the glass transition behavior for the well-annealed single chain globules. PAL single chain globules are prepared by spray drying from the dilute solution. The size and morphology of the

  5. New Precision Orbits of Bright Double-lined Spectroscopic Binaries. X. HD 96511, HR 7578, and KZ Andromedae

    Science.gov (United States)

    Fekel, Francis C.; Henry, Gregory W.; Tomkin, Jocelyn

    2017-09-01

    From an extensive number of newly acquired radial velocities we determine the orbital elements for three late-type dwarf systems, HD 96511, HR 7578, and KZ And. The orbital periods are 18.89737 ± 0.00002, 46.81610 ± 0.00006, and 3.0329113 ± 0.0000005 days, respectively, and all three systems are eccentric, although KZ And is just barely so. We have detected lines of the secondary of HD 96511 for the first time. The orbital dimensions (a 1 sin i and a 2 sin i) and minimum masses (m 1 sin3 i and m 2 sin3 i) of the binary components all have accuracies of 0.2% or better. Extensive photometry of the chromospherically active binary HR 7578 confirms a rather long rotation period of 16.446 ± 0.002 days and that the K3 V components do not eclipse. We have estimated the basic properties of the stars in the three systems and compared those results with evolutionary tracks. The results for KZ And that we computed with the revised Hipparcos parallax of van Leeuwen produce inconsistencies. That parallax appears to be too large, and so, instead, we used the original Hipparcos parallax of the common proper motion primary, which improves the results, although some problems remain.

  6. Investigating the Sensitivity of Emission Line Spectra to the Incident SED in Narrow Line Seyferts and LINERs

    Science.gov (United States)

    Greene, Christopher; Richardson, Chris T.

    2017-01-01

    This research investigates photoionization models of the Narrow Line Region (NLR) of Seyfert galaxies and Low-Ionization Nuclear Emitting Region (LINER) galaxies with the use of the astrophysical code CLOUDY. Groves et al. 2004 attempted to resolve the apparent uniformity of emission line ratios in the NLR through introducing dusty, radiation pressure-dominated photoionization models of AGN. This model assumed a simple power law relation for the Spectral Energy Distribution (SED). Grupe et al. 2010 found a correlation between αuv and αx, and by constraining αuv as a function of αx we developed a photoionization model for the ionizing spectrum of a typical Seyfert Narrow Line Region. The incident SED is based upon the spectral indices αuv, αx, αox , and the blackbody accretion disk temperature Tbb . We set the value of αox based on the average of data collected in Grupe et al. 2010, and fix the value of αuv to αx based on their linear correlation. To check the validity of our model, simulations were run across a range of blackbody accretion disk temperatures and αx, while fixing the hydrogen density, ionization parameter, and elemental abundance of clouds in the NLR. The emission lines produced by these simulations were plotted using standard diagnostic diagrams and compared to emission line data obtained from the Sloan Digital Sky Survey. Our model produces emission lines without significant variation between simulations with αx = 1.42, 1.17, and 2.19, with Tbb ranging from 104 K to 107 K, except with regard to [O I] λ6300/Hα, where our simulated spectra started to fall on the boundary between Seyferts and LINERs. This leads us to examine the ability of our photoionization model to create emission line spectra that are typical of LINERs, as debate still continues over the primary excitation mechanism for LINERs. To adjust our model to fit LINERs, we lower the value of the ionization parameter and discuss the preliminary results within the context of

  7. An investigation of the luminosity-metallicity relation for a large sample of low-metallicity emission-line galaxies

    CERN Document Server

    Guseva, N G; Meyer, H T; Izotov, Yu I; Fricke, K J

    2009-01-01

    (abridged) We present 8.2m VLT spectroscopic observations of 28 HII regions in 16 emission-line galaxies and 3.6m ESO telescope spectroscopic observations of 38 HII regions in 28 emission-line galaxies. These emission-line galaxies were selected mainly from the Data Release 6 (DR6) of the Sloan Digital Sky Survey (SDSS) as metal-deficient galaxy candidates. We collect photometric and high-quality spectroscopic data for a large uniform sample of star forming galaxies including new observations. Our aim is to study the luminosity-metallicity (L-Z) relation for nearby galaxies, especially at its low-metallicity end and compare it with that for higher-redshift galaxies. From our new observations we find that the oxygen abundance in 61 out of the 66 HII regions of our sample ranges from 12+logO/H=7.05 to 8.22. Our sample includes 27 new galaxies with 12+logO/HMg>-20) and nearly 2 dex in its oxygen abundance (7.0<12+logO/H<8.8), allowing us to probe the L-Z relation in the nearby universe down to the lowest c...

  8. Spectroscopic investigations on sorption of uranium onto suspended bentonite. Effects of pH, ionic strength and complexing anions

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Parveen Kumar; Pathak, Priyanath; Mohapatra, Manoj; Mohapatra, Prasanta Kumar [Bhabha Atomic Research Centre, Mumbai (India). Radiochemistry Div.; Yadav, Ashok Kumar; Jha, Sambhunath; Bhattacharyya, Dibyendu [Bhabha Atomic Research Centre, Mumbai (India). Atomic and Molecular Physics Div.

    2015-06-01

    Batch sorption experiments were carried out under aerobic conditions to understand the sorption behavior of U(VI) onto bentonite clay under varying pH (2-8) and ionic strength (I = 0.01 - 1 M (NaClO{sub 4})) conditions. The influences of different complexing anions (1 x 10{sup -4} M) such as oxalic acid (ox), carbonate (CO{sub 3}{sup 2-}), citric acid (cit), and humic acid (HA, 10 mg/L) on the sorption behavior were also investigated. The sorption of U(VI) increased with increasing pH up to pH 6 beyond which a decrease was attributed to the formation of anionic carbonate species. Marginal influence of the change in the ionic strength of the medium on the sorption profile of uranium suggested inner-sphere complexation onto the bentonite surface. The presence of humic acid showed interesting sorption profile with varying pH. Initially, there was an enhancement in the sorption with increased pH followed by a plateau and finally a decrease thereafter due to the formation of aqueous U(VI)-humate complexes. Spectroscopic studies such as UV spectrophotometry, luminescence and extended X-ray absorption fine structure (EXAFS) measurements were also performed to understand the changes in aqueous speciation of U(VI) ion. The luminescence yields of different aqueous U(VI) species followed the order: U(VI){sub Hydroxy} > U(VI){sub HumicAcid} > U(VI){sub carbonate} > U(VI){sub citrate}. The lower luminescence yield of U(VI)carbonate complex can be attributed to the strong dynamic quenching by carbonate at room temperature. The U(VI) samples shows two distinct life-time suggesting the presence of the different luminescent U(VI) species. Similar trend was observed for U(VI)-bentonite suspension in presence/absence of the complexing ligands. There was luminescence quenching for the sorbed U(VI) due to surface complexation. These observations were further supported by spectrophotometric measurements. EXAFS spectra of U(VI) samples were recorded in luminescence mode at the U L{sub 3

  9. Interaction of an aluminum atom with an alkaline earth atom: Spectroscopic and ab initio investigations of AlCa

    Science.gov (United States)

    Behm, Jane M.; Morse, Michael D.; Boldyrev, Alexander I.; Simons, Jack

    1994-10-01

    A spectroscopic analysis of diatomic AlCa generated by laser vaporization of a 2:1 Al:Ca metal alloy followed by supersonic expansion has been completed using resonant two-photon ionization spectroscopy. Four excited electronic states have been identified and investigated in the energy region from 13 500 to 17 900 cm-1. These are the [13.5] 2Πr, the [15.8] 2Σ, the [17.0] 2Δ3/2(?), and the [17.6] 2Δ3/2 states. From rotational analysis excited state bond lengths have been measured for three of the four excited states, and the ground state has been unambiguously determined as a 2Πr state with a weighted least squares value of the ground state bond length of r0` = 3.1479± 0.0010 Å. The ionization energy of the molecule has also been directly determined as 5.072±0.028 eV. Ab initio calculations for the potential energy curves of seven low-lying states of AlCa [X 2Πr, 2Σ+, 4Σ-, 4Πr, 2Πr(2), 2Δ, and 2Σ-] and for the X 1Σ+ ground electronic state of AlCa+ have been carried out. In agreement with experiment, 2Πr is calculated to be the ground electronic state of the neutral molecule. The dissociation energies of AlCa (X 2Πr) into Al(3s23p1,2P0)+Ca(4s2,1S) and for AlCa+ (X 1Σ+) into Al+(3s2,1S)+Ca(4s2,1S) are calculated to be 0.47 and 1.50 eV, respectively. The excited 2Σ+, 4Σ-, 4Πr, 2Πr(2), 2Δ, and 2Σ- states are calculated to lie 0.2, 0.7, 0.7, 1.1, 1.1, and 1.1 eV above X 2Πr, respectively, and the vertical and adiabatic ionization energies of AlCa have been calculated to be 5.03 and 4.97 eV, respectively.

  10. Thermodynamic and Spectroscopic Investigation of Interactions between Reactive Red 223 and Reactive Orange 122 Anionic Dyes and Cetyltrimethyl Ammonium Bromide (CTAB Cationic Surfactant in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Muhammad Irfan

    2014-01-01

    Full Text Available The present study describes the conductometric and spectroscopic study of the interaction of reactive anionic dyes, namely, reactive red 223 and reactive orange 122 with the cationic surfactant cetyltrimethyl ammonium bromide (CTAB. In a systematic investigation, the electrical conductivity data was used to calculate various thermodynamic parameters such as free energy (ΔG, enthalpy (ΔH, and the entropy (ΔS of solubilization. The trend of change in these thermodynamic quantities indicates toward the entropy driven solubilization process. Moreover, the results from spectroscopic data reveal high degree of solubilization, with strong interactions observed in the cases of both dyes and the CTAB. The spontaneous nature of solubilization and binding was evident from the observed negative values of free energies (ΔGp and ΔGb.

  11. Thermodynamic and spectroscopic investigation of interactions between reactive red 223 and reactive orange 122 anionic dyes and cetyltrimethyl ammonium bromide (CTAB) cationic surfactant in aqueous solution.

    Science.gov (United States)

    Irfan, Muhammad; Usman, Muhammad; Mansha, Asim; Rasool, Nasir; Ibrahim, Muhammad; Rana, Usman Ali; Siddiq, Mohammad; Zia-Ul-Haq, Muhammad; Jaafar, Hawa Z E; Khan, Salah Ud-Din

    2014-01-01

    The present study describes the conductometric and spectroscopic study of the interaction of reactive anionic dyes, namely, reactive red 223 and reactive orange 122 with the cationic surfactant cetyltrimethyl ammonium bromide (CTAB). In a systematic investigation, the electrical conductivity data was used to calculate various thermodynamic parameters such as free energy (ΔG), enthalpy (ΔH), and the entropy (ΔS) of solubilization. The trend of change in these thermodynamic quantities indicates toward the entropy driven solubilization process. Moreover, the results from spectroscopic data reveal high degree of solubilization, with strong interactions observed in the cases of both dyes and the CTAB. The spontaneous nature of solubilization and binding was evident from the observed negative values of free energies (ΔG p and ΔG b).

  12. EPR and UV/VIS spectroscopic investigations of VO2+ complexes and compounds formed in alkali pyrosulfates

    DEFF Research Database (Denmark)

    Rasmussen, Søren Birk; Eriksen, Kim Michael; Fehrmann, Rasmus

    2002-01-01

    The catalytically important molten salt-gas system M2S2O7-M2SO4-V2O5/SO2(g) (M = Na. K, Rb, Cs) has been investigated by X- and Q-band EPR spectroscopy. In order to obtain information about the V(IV) complex formation in the melts, samples rather dilute in V2O5 were quenched from the molten state...... at 450-460degreesC to 0degreesC. EPR spectra of the quenched samples were recorded on samples with alkali to vanadium (M/V) ratios 40, 80 and 160. The spectra show that two V(IV) complexes dominate in the melt regardless of the type of alkali metal ion. In systems with low activity of sulfate...... a paramagnetic V(IV) complex with g(parallel to) = 1.915, g(perpendicular to) = 1,978 and line widths 5-15 Gauss is observed. In systems saturated with M2SO4 the obtained EPR spectra show a paramagnetic complex with the g-tensors g(parallel to) = 1.930, g(perpendicular to) = 1.980 and line widths 20-60 Gauss...

  13. Ultra-metal-poor Stars: Spectroscopic Determination of Stellar Atmospheric Parameters Using Iron Non-LTE Line Abundances

    Science.gov (United States)

    Ezzeddine, Rana; Frebel, Anna; Plez, Bertrand

    2017-10-01

    We present new ultra-metal-poor stars parameters with [Fe/H] up-to-date iron model atom with a new recipe for non-elastic hydrogen collision rates. We study the departures from LTE in their atmospheric parameters and show that they can grow up to ∼1.00 dex in [Fe/H], ∼150 K in {T}{eff} and ∼0.5 dex in log g toward the lowest metallicities. Accurate NLTE atmospheric stellar parameters, in particular [Fe/H] being significantly higher, are the first step to eventually providing full NLTE abundance patterns that can be compared with Population III supernova nucleosynthesis yields to derive properties of the first stars. Overall, this maximizes the potential of these likely second-generation stars to investigate the early universe and how the chemical elements were formed.

  14. Investigation of a shock wave in an arcjet He plasma by using an electric probe and emission spectroscope

    Energy Technology Data Exchange (ETDEWEB)

    Kumagawa, G.; Kozue, K.; Fujino, S.; Matsuoka, L.; Endo, T.; Namba, S. [Hiroshima University, Higashi-Hiroshima (Japan); Tamura, N. [National Institute for Fusion Science, Gifu (Japan); Ezumi, N. [Nagano National College of Technology, Nagano (Japan)

    2014-10-15

    We developed an arcjet plasma device having a converging and diverging supersonic conical nozzle. Bright and dark emission structures were formed, depending on the gas pressure in the expansion section. In order to understand the mechanism for the formation of the structures, we evaluated the plasma parameters (electron density and temperature) by using a single probe and a visible emission spectroscope. The analysis of the probe measurements showed no temperature variation around the bright emission region. The plasma density increased significantly by a factor of two. Similar trends were also observed in the spectroscopic measurements. Moreover, the cell width (wavelength) of the shock wave calculated from the compressible fluid dynamics was in good agreement with the experimental value, indicating that this emission structure was caused by a shock cell that could be described by using compressible flow dynamics.

  15. EPR and UV/VIS spectroscopic investigations of VO2+ complexes and compounds formed in alkali pyrosulfates

    DEFF Research Database (Denmark)

    Rasmussen, Søren Birk; Eriksen, Kim Michael; Fehrmann, Rasmus

    2002-01-01

    fraction of the sample occupied by the cation. This indicates that spin-spin relaxation effects are the major contribution to line broadening. Combining information from UV/VIS and EPR spectra shows that the VO2+ unit in the molten salt solvent exhibits electronic properties close to aqueous solutions of V(IV).......The catalytically important molten salt-gas system M2S2O7-M2SO4-V2O5/SO2(g) (M = Na. K, Rb, Cs) has been investigated by X- and Q-band EPR spectroscopy. In order to obtain information about the V(IV) complex formation in the melts, samples rather dilute in V2O5 were quenched from the molten state...

  16. Spectroscopic investigations of newly formed betulin-cyclodextrin guest-host type complexes as potential anti skin cancer candidates

    Science.gov (United States)

    Falamaş, A.; Pînzaru, S. Cînta; Chiş, V.; Dehelean, C.

    2011-05-01

    Betulin and the related compounds found in the outer bark of the birch tree have attached an increasing interest in the pharmaceutical formulation, due to their anti-cancer activity. Betulin exhibits a very poor solubility; therefore new approaches are required, such as the preparation of the guest-host type complexes using cyclodextrins. The new prepared betulin - hydroxy-propyl-gamma-cyclodextrin (HPGCD) complexes have been obtained and characterized using vibrational spectroscopic techniques in conjunction with quantum chemical calculation.

  17. Candidate Water Vapor Lines to Locate the H2O Snowline through High-dispersion Spectroscopic Observations. II. The Case of a Herbig Ae Star

    Science.gov (United States)

    Notsu, Shota; Nomura, Hideko; Ishimoto, Daiki; Walsh, Catherine; Honda, Mitsuhiko; Hirota, Tomoya; Millar, T. J.

    2017-02-01

    Observationally measuring the location of the {{{H}}}2{{O}} snowline is crucial for understanding planetesimal and planet formation processes, and the origin of water on Earth. In disks around Herbig Ae stars (T * ∼ 10,000 K, M * ≳ 2.5M ⊙), the position of the {{{H}}}2{{O}} snowline is farther from the central star compared with that around cooler and less massive T Tauri stars. Thus, the {{{H}}}2{{O}} emission line fluxes from the region within the {{{H}}}2{{O}} snowline are expected to be stronger. In this paper, we calculate the chemical composition of a Herbig Ae disk using chemical kinetics. Next, we calculate the {{{H}}}2{{O}} emission line profiles and investigate the properties of candidate water lines across a wide range of wavelengths (from mid-infrared to submillimeter) that can locate the position of the {{{H}}}2{{O}} snowline. Those lines identified have small Einstein A coefficients (∼ {10}-6{--}{10}-3 s‑1) and relatively high upper-state energies (∼1000 K). The total fluxes tend to increase with decreasing wavelengths. We investigate the possibility of future observations (e.g., ALMA, SPICA/SMI-HRS) locating the position of the {{{H}}}2{{O}} snowline. Since the fluxes of those identified lines from Herbig Ae disks are stronger than those from T Tauri disks, the possibility of a successful detection is expected to increase for a Herbig Ae disk.

  18. Tools and Methods of Low-Frequency Radio Recombination Lines Investigations

    Science.gov (United States)

    Konovalenko, A. A.; Stepkin, S. V.; Mukha, D. V.; Vasilkovskiy, E. V.

    In the report the tools and methods of observations of radio recombination lines which are carried out at Institute of Radio Astronomy of the National Academy of Sciences of Ukraine using the world's largest decameter radio telescope UTR-2 (arrays "South - North" and "East - West") are described. The low-frequency radio recombination lines can be used as effective means of the low-density partially ionized interstellar medium diagnostic. However, low intensities of the lines and high level of interferences makes such investigations very difficult and impose high requirements to equipment. Observations are carried out with the 4096-channel digital correlometer and new generation digital spectral processors with 8192 spectral channels. Currently, the systematic observations of radio recombination lines have been carried out in the directions of remnants of supernova stars, Galactic plane, nebulas and dust clouds. Experiments aimed to finding the redshifted line of neutral hydrogen HI which arises in the cosmological epochs of reionization in the range 8 - 32 MHz are carried out. The carbon radio recombination lines have been detected in the direction of Cassiopeia A in the broad range of frequencies from 20 to 32 MHz. The carbon radio recombination line, corresponding to the transitions to atomic level with number of 1009 (these corresponds to the Bohr size of atom near 0,1 mm) have been registered.

  19. Construction of near-isogenic lines to investigate the efficiency of different resistance genes to anthracnose.

    Science.gov (United States)

    Mahé, A; Bannerot, H; Grisvard, J

    1995-05-01

    A suitable experimental model was designed with the aim of investigating the specific effect of different resistance genes in the Phaseolus vulgaris - Colletotrichum lindemuthianum interaction. The four resistance genes examined were chosen because they confer a different phenotype (resistance or susceptibility) to the lines carrying them when challenged by a range of C. lindemuthianum races. These different resistance genes were introgressed independently into the same susceptible recipient line. The isogenicity of the five near-isogenic lines (NILs) thus obtained (four resistant lines, one susceptible line = recipient line) was assessed by a RAPD analysis. The hypersensitive reaction occurred at the same time after infection, whatever the resistance gene present, when the NILs were challenged by the avirulent race 9 of the pathogen. In contrast, the pathogen development was arrested more or less rapidly in the different NILs. At the first stages of the infection process, the transcripts encoding phenylalanine ammonia-lyase were accumulated to a different extent in the different resistant NILs but always to a higher level than in the susceptible recipient line. These results suggest that the different resistance genes operate through more than one way in the production of defense factors.

  20. FTIR, Raman, and UV-Vis spectroscopic and DFT investigations of the structure of iron-lead-tellurate glasses.

    Science.gov (United States)

    Rada, Simona; Dehelean, Adriana; Culea, Eugen

    2011-08-01

    In this work, the effects of iron ion intercalations on lead-tellurate glasses were investigated via FTIR, Raman and UV-Vis spectroscopies. This homogeneous glass system has compositions xFe(2)O(3)·(100-x)[4TeO(2)·PbO(2)], where x = 0-60 mol%. The presented observations in these mechanisms show that the lead ions have a pronounced affinity towards [TeO(3)] structural units, resulting in the deformation of the Te-O-Te linkages, and leading to the intercalation of [PbO( n )] (n = 3, 4) and [FeO( n )] (n = 4, 6) entities in the [TeO(4)] chain network. The formation of negatively charged [FeO(4)](1-) structural units implies the attraction of Pb(2+) ions in order to compensate for this electrical charge. Upon increasing the Fe(2)O(3) content to 60 mol%, the network can accommodate an excess of oxygen through the formation of [FeO(6)] structural units and the conversion of [TeO(4)] into [TeO(3)] structural units. For even higher Fe(2)O(3) contents, Raman spectra indicate a greater degree of depolymerization of the vitreous network than FTIR spectra do. The bands due to the Pb-O bond vibrations are very strongly polarized and the [TeO(4)] structural units convert into [TeO(3)] units via an intermediate coordination stage termed "[TeO(3+1)]" structural units. Our UV-Vis spectroscopic data show two mechanisms: (i) the conversion of the Fe(3+) to Fe(2+) at the same time as the oxidation of Pb(2+) to Pb(+4) ions for samples with low Fe(2)O(3) contents; (ii) when the Fe(2)O(3) content is high (x ≥ 50 mol%), the Fe(2+) ions capture positive holes and are transferred to Fe(3+) ions through a photochemical reaction, while the Pb(2+) ions are formed by the reduction of Pb(4+) ions. DFT calculations show that the addition of Fe(2)O(3) to lead-tellurate glasses seems to break the axial Te-O bonds, and the [TeO(4)] structural units are gradually transformed into [TeO(3+1)]- and [TeO(3)]-type polyhedra. Analyzing these data further indicates a gradual

  1. Chemical investigations of isotope separation on line target units for carbon and nitrogen beams

    CERN Document Server

    Franberg, H; Gäggeler, H W; Köster, U

    2006-01-01

    Radioactive ion beams (RIBs) are of significant interest in a number of applications. Isotope separation on line (ISOL) facilities provide RIB with high beam intensities and good beam quality. An atom that is produced within the ISOL target will first diffuse out from the target material. During the effusion towards the transfer line and into the ion source the many contacts with the surrounding surfaces may cause unacceptable delays in the transport and, hence, losses of the shorter-lived isotopes. We performed systematic chemical investigations of adsorption in a temperature and concentration regime relevant for ISOL targets and ion source units, with regard to CO/sub x/ and NOmaterials are potential construction materials for the above-mentioned areas. Off-line and on-line tests have been performed using a gas thermochromatography setup with radioactive tracers. The experiments were performed at the production of tracers for atmospheric chemistry (PROTRAC) facility at the Paul Schener Institute in Villigen...

  2. Noninvasive Phosphorus Magnetic Resonance Spectroscopic Imaging Predicts Outcome to First-line Chemotherapy in Newly Diagnosed Patients with Diffuse Large B-Cell Lymphoma

    NARCIS (Netherlands)

    Arias-Mendoza, F.; Payne, G.S.; Zakian, K.; Stubbs, M.; O'Connor, O.A.; Mojahed, H.; Smith, M.R.; Schwarz, A.J.; Shukla-Dave, A.; Howe, F.; Poptani, H.; Lee, S.-C.; Pettengel, R.; Schuster, S.J.; Cunningham, D.; Heerschap, A.; Glickson, J.D.; Griffiths, J.R.; Koutcher, J.A.; Leach, M.O.; Brown, T.R.

    2013-01-01

    Based on their association with malignant proliferation, using noninvasive phosphorus MR spectroscopic imaging ((31)P MRSI), we measured the tumor content of the phospholipid-related phosphomonoesters (PME), phosphoethanolamine and phospholcholine, and its correlation with treatment outcome in newly

  3. Line shapes investigations in Yugoslavia and Serbia V (1997-2000). (Bibliography and citation index)

    Science.gov (United States)

    Dimitrijević, Milan S.

    2001-05-01

    The first part of the publication contains a review and anylysis of the results of spectral line shapes investigations in Yugoslavia and Serbia for 1997-2000. In the second part, the bibliography of the contributions of Yugoslav and Serbian scientists for 1997-2000 is given, together with the Citation Index for 1997-2000 for articles published 1962-2000.

  4. Line shapes investigations in Yugoslavia and Serbia III (1989 - 1993). (Bibliography and citation index).

    Science.gov (United States)

    Dimitrijević, M. S.

    1994-08-01

    The first part of the publication contains review and analysis of the results of spectral line shapes investigations in Yugoslavia and Serbia in the period 1989 - 1993. In the second part, the bibliography of the contributions of Yugoslav and Serbian scientists is given, together with the citation index.

  5. Line shapes investigations in Yugoslavia and Serbia IV (1993 - 1997). (Bibliography and citation index).

    Science.gov (United States)

    Dimitrijević, M. S.

    1997-09-01

    The first part of this publication contains review and analysis of the results of spectral line shapes investigations in Yugoslavia and Serbia for 1993 - 1997. In the second part, the bibliography of the contributions of Yugoslav and Serbian scientists for 1993 - 1997 is given, together with the citation index for 1993 - 1997 for articles published 1962 - 1997.

  6. Live-line insulator washing: Experimental investigation to assess safety and efficiency requirements

    Energy Technology Data Exchange (ETDEWEB)

    Perin, D.; Pigini, A.; Visintainer, I. [CESI, Milano (Italy); Channakeshava; Ramamoorty, M. [CPRI, Bangalore (India)

    1994-12-31

    A laboratory investigation was carried out to study live-line washing of insulators, with special attention to the two washing procedures which adopt hand-held nozzles or helicopter mounted nozzles. The aspects related to safety and those related to efficiency and reliability were considered. On the basis of the results, safe working distances and indications to define optimal washing procedures were derived.

  7. Investigation of air entrapment and weld line defects in micro injection moulded thermoplastic elastomer micro rings

    DEFF Research Database (Denmark)

    Hasnaes, F.B.; Tosello, Guido; Calaon, Matteo;

    2015-01-01

    The micro injection moulding (μIM) process for the production of micro rings in thermoplastic elastomers (TPE) was investigated and optimized. The objective was to minimize the formation of air entrapments and the depth of micro weld line created on the surface of the TPE micro moulded rings...

  8. Nondestructive depth-resolved spectroscopic investigation of the heavily intermixed In2S3/Cu(In,Ga)Se2 interface

    Energy Technology Data Exchange (ETDEWEB)

    Bar, Marcus; Barreau, N.; Couzinie-Devy, F.; Pookpanratana, S.; Klaer, J.; Blum, M.; Zhang, Y.; Yang, W.; Denlinger, J.D.; Schock, H.W.; Weinhardt, L.; Kessler, J.; Heske, Clemens

    2010-04-06

    The chemical structure of the interface between a nominal In2S3 buffer and a Cu(In,Ga)Se2 (CIGSe) thin-film solar cell absorber was investigated by soft x-ray photoelectron and emission spectroscopy. We find a heavily intermixed, complex interface structure, in which Cu diffuses into (and Na through) the buffer layer, while the CIGSe absorber surface/interface region is partially sulfurized. Based on our spectroscopic analysis, a comprehensive picture of the chemical interface structure is proposed.

  9. Nondestructive depth-resolved spectroscopic investigation of the heavily intermixed In2S3/Cu(In,Ga)Se2 interface

    Science.gov (United States)

    Bär, M.; Barreau, N.; Couzinié-Devy, F.; Pookpanratana, S.; Klaer, J.; Blum, M.; Zhang, Y.; Yang, W.; Denlinger, J. D.; Schock, H.-W.; Weinhardt, L.; Kessler, J.; Heske, C.

    2010-05-01

    The chemical structure of the interface between a nominal In2S3 buffer and a Cu(In,Ga)Se2 (CIGSe) thin-film solar cell absorber was investigated by soft x-ray photoelectron and emission spectroscopy. We find a heavily intermixed, complex interface structure, in which Cu diffuses into (and Na through) the buffer layer, while the CIGSe absorber surface/interface region is partially sulfurized. Based on our spectroscopic analysis, a comprehensive picture of the chemical interface structure is proposed.

  10. Numerical Investigation of Flow Losses through Discharge Line of Household Type Refrigerator Compressors

    Science.gov (United States)

    Yesilaydin, I.; Erbay, L. B.

    2015-08-01

    The technological developments, competition and energy policies are forcing the refrigeration market to increase the efficiency of their products as never before. The component that determines the performance and efficiency of the refrigeration system is the compressor, which is the major energy consumer in a compression refrigeration system. One of the essential elements of the total compressor efficiency is the discharge line flow efficiency that is subjected to this study. In this paper, the effects of design parameters on flow loses at discharge line of a hermetic reciprocating compressor were investigated with numerical flow analysis. At this study, three conceptual designs were modelled based on the discharge line design parameters such as line diameter, resonator volumes and line length. The pressure drop regions are determined by CFD analyses and they compared against the base model. Analyses are carried out by using commercial CFD software. Furthermore, the obtained numerical results were compared to experimental data and presented a good agreement in terms of pressure drop and discharge line flow efficiency.

  11. Parameters Investigation of Mathematical Model of Productivity for Automated Line with Availability by DMAIC Methodology

    Directory of Open Access Journals (Sweden)

    Tan Chan Sin

    2014-01-01

    Full Text Available Automated line is widely applied in industry especially for mass production with less variety product. Productivity is one of the important criteria in automated line as well as industry which directly present the outputs and profits. Forecast of productivity in industry accurately in order to achieve the customer demand and the forecast result is calculated by using mathematical model. Mathematical model of productivity with availability for automated line has been introduced to express the productivity in terms of single level of reliability for stations and mechanisms. Since this mathematical model of productivity with availability cannot achieve close enough productivity compared to actual one due to lack of parameters consideration, the enhancement of mathematical model is required to consider and add the loss parameters that is not considered in current model. This paper presents the investigation parameters of productivity losses investigated by using DMAIC (Define, Measure, Analyze, Improve, and Control concept and PACE Prioritization Matrix (Priority, Action, Consider, and Eliminate. The investigated parameters are important for further improvement of mathematical model of productivity with availability to develop robust mathematical model of productivity in automated line.

  12. Behavior of H(sub2)O and OH in lawsonite : a single crystal neutron diffraction and Raman spectroscopic investigation.

    Energy Technology Data Exchange (ETDEWEB)

    Kolesov, B. A.; Lager, G. A.; Schultz, A. J.; Russian Academy of Science; Univ. of Louisville

    2008-01-01

    Neutron diffraction and polarized single-crystal Raman spectroscopic measurements were made on the high-pressure silicate lawsonite, CaAl{sub 2}(Si{sub 2}O{sub 7})(OH){sub 2} {center_dot} H{sub 2}O, from Tiburon Peninsula, California. For the diffraction measurements, intensity reflection data were collected at temperatures of 295, 110 and 20 K using time-of-flight neutron diffraction methods to further examine two reversible, order-disorder type phase transitions occurring at 273 and 155 K [Cmcm (> 273 K) {yields} Pmcn (< 273 K) {yields} P2{sub 1}cn (< 155 K)]. These data are also used to model the H atom displacements in lawsonite as a function of temperature and to provide better insight into the nature of H bonding. The Raman spectroscopic measurements (2500 to 4000 cm{sup -1} at 4 {ge} T {ge} 300 K) were carried out on the same crystal used for the neutron diffraction study. Four OH-related bands are observed between 2700 and 3600 cm{sup -1}. The OH groups and H{sub 2}O molecules, which are linked by hydrogen bonding, build quasi one-dimensional chains in lawsonite, that run parallel to [001] and thus a model consisting of isolated oscillators cannot be used to interpret the spectra at ambient temperature. A notable feature of spectral behavior at 240-260 K in the vicinity of the Cmcm {leftrightarrow} Pmcn phase transition is the change-over of strong hydrogen bonding from the OH group to the H{sub 2}O molecule. The lowest-wavenumber OH(H{sub 2}O) band at 2780 cm{sup -1} at 4 K is broad and asymmetric, which is related to strong hydrogen bonding, and is characterized by strong anharmonicity. This band was deconvoluted into a number of combination modes consisting of an internal-H{sub 2}O and various external-H{sub 2}O vibrations.

  13. Chemical and spectroscopic investigation of the Raphael's cartoon of the School of Athens from the Pinacoteca Ambrosiana

    Science.gov (United States)

    Ioele, Marcella; Sodo, Armida; Casanova Municchia, Annalaura; Ricci, Maria Antonietta; Russo, Alfonso Pio

    2016-12-01

    The cartoon of "The School of Athens", realized by the famous artist Raffaello Sanzio, is a masterpiece of Italian Renaissance. It is a full-scale (804 × 285 cm2) preparatory cartoon, stored at the Pinacoteca Ambrosiana (Milan, Italy). In order to characterize the cartoon and the drawing and to investigate its conservation state, several scientific analyses have been performed, both in situ and on sampled fragments. This multi-analytical approach has identified most of the materials used in the original drawing and in restored areas and provided a map of previous restoration works. Here we report the results obtained by Raman and FTIR spectroscopy, scanning electron microscopy equipped with X-ray micro-analysis (SEM-EDS), pH measurements and micro-chemical tests. pH measurements proved the absence of an acidic decay of the paper. The original paper from linen and hemp fibres is well preserved. It is filled with calcium carbonate and has received a light sizing with protein glue, now almost completely transformed into oxalates. 1797 French intervention paper is of lower quality and has been covered with a patina of lead white in Arabic gum, most likely in an attempt to match the colour to the tone of the original. Both papers are stuck to a support paper with flour glue (containing starch and gluten) and glued with the same adhesive to a canvas lining. In situ Raman spectroscopy has clearly shown that the original drawing was in charcoal and lead white, while the restored areas have been drawn using charcoal and graphite.

  14. Spectroscopic investigation of new fullerene based acceptors for organic solar cells; Spektroskopische Untersuchung neuartiger Fullerenakzeptoren fuer organische Solarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Liedte, Moritz Nils

    2012-04-27

    high open circuit voltage of 835 mV in the devices produced, but also a rather low current density. I tried to understand the processes in the charge carrier generation and extraction process causing this. Using several measurement techniques, combined with general knowledge about comparable endohedral fullerenes from the literature, I was able to identify an internal charge transfer of electrons from the lutetium atoms encaged in the C{sub 80} to the fullerene bulk as origin The results presented in this work give further indications for the advantages of using C{sub 70} based fullerene acceptors in organic solar cells to raise the total power conversion efficiencies of these devices, despite the higher production costs. The identification of anion signatures of different fullerenes show an additional method to monitor the excitation processes by optical spectroscopy in bulk-heterojunction devices. My research regarding the Lu{sub 3}N rate at C{sub 80} molecule showed a general effect regarding this class of molecules, that will be important for any further synthesizes or application of such molecules in organic photovoltaics. While the projects regarding the dimer acceptors and the Lu{sub 3}N rate at C{sub 80} molecule were completed in this work, the analysis of spectroscopic anion signatures left some open questions, especially for large fullerenes. Further investigations using spin sensitive or time resolved techniques, as available in our research group, could be useful to gather more detailed information on this topic. Also trying to get some PC{sub 81}BM for photoinduced absorption measurements, alone and in blend with several polymers, might be another way to energetically pinpoint the anion signature on C{sub 80}.

  15. Investigation of the Freeze-Lining Formed in an Industrial Copper Converting Calcium Ferrite Slag

    Science.gov (United States)

    Fallah-Mehrjardi, Ata; Jansson, Jani; Taskinen, Pekka; Hayes, Peter C.; Jak, Evgueni

    2014-06-01

    Pyrometallurgical coppermaking processes are operated under intensive reaction conditions; high process temperatures and vigorous bath agitation is used to increase the kinetics of reactions and to achieve high smelter throughput. Slag freeze-lining reactor wall protection is a widely used technology in coppermaking processes, such as flash smelting and converting reactors. Freeze-linings mitigate and resist the effects of thermal and chemical attack by aggressive slags. In this laboratory-based study, a water-cooled probe "cold finger" technique has been used to investigate freeze-lining formation with calcium ferrite slags in equilibrium with metallic copper; the slag composition reflects that used in the industrial copper flash converting furnace of Rio Tinto—Kennecott Utah Copper. The effects of probe immersion times on the thickness and microstructures in the freeze-lining deposits have been investigated. A range of complex oxide solutions and copper-containing phases have been found in the deposits. The phase assemblages formed from the industrial calcium ferrite slag in the steady-state deposit are very complex and information on the phase equilibria of the multi-component systems with addition of minor elements may not be available. Subsolidus and subliquidus phase equilibria in the Cu-Ca-Fe-O system at metallic copper saturation along with interpolated temperature across the deposit, microstructural changes and compositional trends in the phases in the deposit have been used to understand the formation and characteristics of the phases in the steady-state freeze-lining. Also, it has been shown that under steady-state conditions a dense sealing layer consisting primarily of the spinel primary phase is formed at the deposit/liquid interface; however, the interface temperature is below the liquidus temperature. The findings of the study have potentially important implications for the operation of the converting furnace and the design of freeze linings in

  16. Investigations of Spectroscopic Factors and Sum Rules from the Single Neutron Transfer Reaction 111Cd(d→$\\overrightarrow {\\rm{d}} $,p112Cd

    Directory of Open Access Journals (Sweden)

    Jamieson D.S.

    2014-03-01

    Full Text Available Cadmium isotopes have been presented for decades as excellent examples of vibrational nuclei, with low-lying levels interpreted as multi-phonon quadrupole, octupole, and mixed-symmetry states. A large amount of spectroscopic data has been obtained through various experimental studies of cadmiumisotopes. In the present work, the 111Cd(d→$\\overrightarrow {\\rm{d}} $,p112Cd reaction was used to investigate the single-particle structure of the 112Cd nucleus. A 22 MeV beam of polarized deuterons was obtained at the Maier-Leibnitz laboratory in Garching, Germany. The reaction ejectiles were momentum analyzed using a Q3D spectrograph, and 130 levels have been identified up to 4.2 MeV of excitation energy. Using DWBA analysis with optical model calculations, spin-parity assignments have been made for observed levels, and spectroscopic factors have been extracted from the experimental angular distributions of differential cross section and analyzing power. In this high energy resolution investigation, many additional levels have been observed compared with the previous (d,p study using 8 MeV deuterons [1]. There were a total of 44 new levels observed, and the parity assignments of 34 levels were improved.

  17. INVESTIGATION OF A DYNAMIC POWER LINE RATING CONCEPT FOR IMPROVED WIND ENERGY INTEGRATION OVER COMPLEX TERRAIN

    Energy Technology Data Exchange (ETDEWEB)

    Jake P. Gentle; Kurt S Myers; Tyler B Phillips; Inanc Senocak; Phil Anderson

    2014-08-01

    Dynamic Line Rating (DLR) is a smart grid technology that allows the rating of power line to be based on real-time conductor temperature dependent on local weather conditions. In current practice overhead power lines are generally given a conservative rating based on worst case weather conditions. Using historical weather data collected over a test bed area, we demonstrate there is often additional transmission capacity not being utilized with the current static rating practice. We investigate a new dynamic line rating methodology using computational fluid dynamics (CFD) to determine wind conditions along transmission lines at dense intervals. Simulated results are used to determine conductor temperature by calculating the transient thermal response of the conductor under variable environmental conditions. In calculating the conductor temperature, we use both a calculation with steady-state assumption and a transient calculation. Under low wind conditions, steady-state assumption predicts higher conductor temperatures that could lead to curtailments, whereas transient calculations produce conductor temperatures that are significantly lower, implying the availability of additional transmission capacity.

  18. Ultraviolet Emission Lines of Si ii in Quasars: Investigating the "Si ii Disaster"

    Science.gov (United States)

    Laha, Sibasish; Keenan, Francis P.; Ferland, Gary J.; Ramsbottom, Catherine A.; Aggarwal, Kanti M.

    2016-07-01

    The observed line intensity ratios of the Si ii λ1263 and λ1307 multiplets to that of Si ii λ1814 in the broad-line region (BLR) of quasars are both an order of magnitude larger than the theoretical values. This was first pointed out by Baldwin et al., who termed it the “Si ii disaster,” and it has remained unresolved. We investigate the problem in the light of newly published atomic data for Si ii. Specifically, we perform BLR calculations using several different atomic data sets within the CLOUDY modeling code under optically thick quasar cloud conditions. In addition, we test for selective pumping by the source photons or intrinsic galactic reddening as possible causes for the discrepancy, and we also consider blending with other species. However, we find that none of the options investigated resolve the Si ii disaster, with the potential exception of microturbulent velocity broadening and line blending. We find that a larger microturbulent velocity (˜ 500 {km} {{{s}}}-1) may solve the Si ii disaster through continuum pumping and other effects. The CLOUDY models indicate strong blending of the Si ii λ1307 multiplet with emission lines of O i, although the predicted degree of blending is incompatible with the observed λ1263/λ1307 intensity ratios. Clearly, more work is required on the quasar modeling of not just the Si ii lines but also nearby transitions (in particular those of O i) to fully investigate whether blending may be responsible for the Si ii disaster.

  19. Ultraviolet emission lines of Si II in quasars --- investigating the "Si II disaster"

    CERN Document Server

    Laha, Sibasish; Ferland, Gary J; Ramsbottom, Catherine A; Aggarwal, Kanti M

    2016-01-01

    The observed line intensity ratios of the Si II 1263 and 1307 \\AA\\ multiplets to that of Si II 1814\\,\\AA\\ in the broad line region of quasars are both an order of magnitude larger than the theoretical values. This was first pointed out by Baldwin et al. (1996), who termed it the "Si II disaster", and it has remained unresolved. We investigate the problem in the light of newly-published atomic data for Si II. Specifically, we perform broad line region calculations using several different atomic datasets within the CLOUDY modeling code under optically thick quasar cloud conditions. In addition, we test for selective pumping by the source photons or intrinsic galactic reddening as possible causes for the discrepancy, and also consider blending with other species. However, we find that none of the options investigated resolves the Si II disaster, with the potential exception of microturbulent velocity broadening and line blending. We find that a larger microturbulent velocity ($\\sim 500 \\rm \\, kms^{-1}$) may solv...

  20. Emission-Line Galaxies from the Hubble Space Telescope Probing Evolution and Reionization Spectroscopically (PEARS) Grism Survey. II: The Complete Sample

    CERN Document Server

    Pirzkal, Nor; Ly, Chun; Malhotra, Sangeeta; Rhoads, James E; Grogin, Norman A; Dahlen, Tomas; Meurer, Gerhardt R; Walsh, Jeremy R; Hathi, Nimish P; Cohen, Seth H; Bellini, Andrea; Holwerda, Benne W; Straughn, Amber N; Mechtley, Matthew

    2012-01-01

    We present a full analysis of the Probing Evolution And Reionization Spectroscopically (PEARS) slitess grism spectroscopic data obtained with the Advanced Camera for Surveys on HST. PEARS covers fields within both the Great Observatories Origins Deep Survey (GOODS) North and South fields, making it ideal as a random survey of galaxies, as well as the availability of a wide variety of ancillary observations to support the spectroscopic results. Using the PEARS data we are able to identify star forming galaxies within the redshift volume 0 1e9} M_sun decreases by an order of magnitude at z<0.5 relative to the number at 0.5

  1. LINES

    Directory of Open Access Journals (Sweden)

    Minas Bakalchev

    2015-10-01

    Full Text Available The perception of elements in a system often creates their interdependence, interconditionality, and suppression. The lines from a basic geometrical element have become the model of a reductive world based on isolation according to certain criteria such as function, structure, and social organization. Their traces are experienced in the contemporary world as fragments or ruins of a system of domination of an assumed hierarchical unity. How can one release oneself from such dependence or determinism? How can the lines become less “systematic” and forms more autonomous, and less reductive? How is a form released from modernistic determinism on the new controversial ground? How can these elements or forms of representation become forms of action in the present complex world? In this paper, the meaning of lines through the ideas of Le Corbusier, Leonidov, Picasso, and Hitchcock is presented. Spatial research was made through a series of examples arising from the projects of the architectural studio “Residential Transformations”, which was a backbone for mapping the possibilities ranging from playfulness to exactness, as tactics of transformation in the different contexts of the contemporary world.

  2. Live-line insulator washing: Experimental investigation to assess safety and efficiency requirements

    Energy Technology Data Exchange (ETDEWEB)

    Perin, D.; Pigini, A.; Visintainer, I. [CESI, Milano (Italy); Ramamoorty, C.M. [CPRI, Bangalore (India)

    1995-01-01

    A laboratory investigation was carried out to study live-line washing of insulators, with special attention to the two washing procedures which adopt hand-held jet nozzles and helicopter mounted nozzles. The aspects related to safety and those related to efficiency and reliability were considered. On the basis of the results, site working distances and indications to define optimal washing procedures were derived.

  3. Investigating the biochemical progression of liver disease through fibrosis, cirrhosis, dysplasia, and hepatocellular carcinoma using Fourier transform infrared spectroscopic imaging

    Science.gov (United States)

    Sreedhar, Hari; Pant, Mamta; Ronquillo, Nemencio R.; Davidson, Bennett; Nguyen, Peter; Chennuri, Rohini; Choi, Jacqueline; Herrera, Joaquin A.; Hinojosa, Ana C.; Jin, Ming; Kajdacsy-Balla, Andre; Guzman, Grace; Walsh, Michael J.

    2014-03-01

    Hepatocellular carcinoma (HCC) is the most common form of primary hepatic carcinoma. HCC ranks the fourth most prevalent malignant tumor and the third leading cause of cancer related death in the world. Hepatocellular carcinoma develops in the context of chronic liver disease and its evolution is characterized by progression through intermediate stages to advanced disease and possibly even death. The primary sequence of hepatocarcinogenesis includes the development of cirrhosis, followed by dysplasia, and hepatocellular carcinoma.1 We addressed the utility of Fourier Transform Infrared (FT-IR) spectroscopic imaging, both as a diagnostic tool of the different stages of the disease and to gain insight into the biochemical process associated with disease progression. Tissue microarrays were obtained from the University of Illinois at Chicago tissue bank consisting of liver explants from 12 transplant patients. Tissue core biopsies were obtained from each explant targeting regions of normal, liver cell dysplasia including large cell change and small cell change, and hepatocellular carcinoma. We obtained FT-IR images of these tissues using a modified FT-IR system with high definition capabilities. Firstly, a supervised spectral classifier was built to discriminate between normal and cancerous hepatocytes. Secondly, an expanded classifier was built to discriminate small cell and large cell changes in liver disease. With the emerging advances in FT-IR instrumentation and computation there is a strong drive to develop this technology as a powerful adjunct to current histopathology approaches to improve disease diagnosis and prognosis.

  4. A Comprehensive Spectroscopic and Computational Investigation to Probe the Interaction of Antineoplastic Drug Nordihydroguaiaretic Acid with Serum Albumins.

    Directory of Open Access Journals (Sweden)

    Saima Nusrat

    Full Text Available Exogenous drugs that are used as antidote against chemotheray, inflammation or viral infection, gets absorbed and interacts reversibly to the major serum transport protein i.e. albumins, upon entering the circulatory system. To have a structural guideline in the rational drug designing and in the synthesis of drugs with greater efficacy, the binding mechanism of an antineoplastic and anti-inflammatory drug Nordihydroguaiaretic acid (NDGA with human and bovine serum albumins (HSA & BSA were examined by spectroscopic and computational methods. NDGA binds to site II of HSA with binding constant (Kb ~105 M-1 and free energy (ΔG ~ -7.5 kcal.mol-1. It also binds at site II of BSA but with lesser binding affinity (Kb ~105 M-1 and ΔG ~ -6.5 kcal.mol-1. The negative value of ΔG, ΔH and ΔS for both the albumins at three different temperatures confirmed that the complex formation process between albumins and NDGA is spontaneous and exothermic. Furthermore, hydrogen bonds and hydrophobic interactions are the main forces involved in complex formation of NDGA with both the albumins as evaluated from fluorescence and molecular docking results. Binding of NDGA to both the albumins alter the conformation and causes minor change in the secondary structure of proteins as indicated by the CD spectra.

  5. Probing the interaction of a therapeutic flavonoid, pinostrobin with human serum albumin: multiple spectroscopic and molecular modeling investigations.

    Directory of Open Access Journals (Sweden)

    Shevin R Feroz

    Full Text Available Interaction of a pharmacologically important flavonoid, pinostrobin (PS with the major transport protein of human blood circulation, human serum albumin (HSA has been examined using a multitude of spectroscopic techniques and molecular docking studies. Analysis of the fluorescence quenching data showed a moderate binding affinity (1.03 × 10(5 M(-1 at 25°C between PS and HSA with a 1∶1 stoichiometry. Thermodynamic analysis of the binding data (ΔS = +44.06 J mol(-1 K(-1 and ΔH = -15.48 kJ mol(-1 and molecular simulation results suggested the involvement of hydrophobic and van der Waals forces, as well as hydrogen bonding in the complex formation. Both secondary and tertiary structural perturbations in HSA were observed upon PS binding, as revealed by intrinsic, synchronous, and three-dimensional fluorescence results. Far-UV circular dichroism data revealed increased thermal stability of the protein upon complexation with PS. Competitive drug displacement results suggested the binding site of PS on HSA as Sudlow's site I, located at subdomain IIA, and was well supported by the molecular modelling data.

  6. Spectroscopic investigation of the A (1)A(")-X (1)A(') electronic transition of HSiNCO.

    Science.gov (United States)

    Dover, Matthew R; Evans, Corey J; Western, Colin M

    2009-09-28

    The first spectroscopic observation of the previously unknown species HSiNCO has been reported. HSiNCO was generated by the fragmentation of trimethylsilylisocyanate with a high-voltage discharge source. The 0(0)(0) band of the A (1)A(")-X (1)A(') transition has been recorded with full rotational resolution using laser-induced fluorescence spectroscopy and ground and excited state rotational and centrifugal distortion constants determined. Ten additional vibrational bands belonging to HSiNCO have also been observed in the laser-induced fluorescence spectrum and have been assigned based on predicted anharmonic vibrational frequencies. Due to the large change in geometry upon excitation, a number of axis-rotation peaks have been observed in the 0(0)(0) band and the axis-rotation angle (theta(T)) has been estimated to be 0.6 degrees +/-0.2 degrees. Dispersed fluorescence spectroscopy has been carried out and nu(8) (the N-C-O out-of-plane bending mode) and a number of overtones of nu(4) (the Si-H wagging mode) have been observed in the ground electronic state.

  7. Spectroscopic investigation of the A~ 1A''-X~ 1A' electronic transition of HSiNCO

    Science.gov (United States)

    Dover, Matthew R.; Evans, Corey J.; Western, Colin M.

    2009-09-01

    The first spectroscopic observation of the previously unknown species HSiNCO has been reported. HSiNCO was generated by the fragmentation of trimethylsilylisocyanate with a high-voltage discharge source. The 000 band of the à A1″-X˜ A1' transition has been recorded with full rotational resolution using laser-induced fluorescence spectroscopy and ground and excited state rotational and centrifugal distortion constants determined. Ten additional vibrational bands belonging to HSiNCO have also been observed in the laser-induced fluorescence spectrum and have been assigned based on predicted anharmonic vibrational frequencies. Due to the large change in geometry upon excitation, a number of axis-rotation peaks have been observed in the 000 band and the axis-rotation angle (θT) has been estimated to be 0.6°±0.2°. Dispersed fluorescence spectroscopy has been carried out and ν8 (the N-C-O out-of-plane bending mode) and a number of overtones of ν4 (the Si-H wagging mode) have been observed in the ground electronic state.

  8. 4-Cyano-α-methyl-l-phenylalanine as a spectroscopic marker for the investigation of peptaibiotic-membrane interactions.

    Science.gov (United States)

    De Zotti, Marta; Bobone, Sara; Bortolotti, Annalisa; Longo, Edoardo; Biondi, Barbara; Peggion, Cristina; Formaggio, Fernando; Toniolo, Claudio; Dalla Bona, Andrea; Kaptein, Bernard; Stella, Lorenzo

    2015-04-01

    Two analogs of the ten-amino acid residue, membrane-active lipopeptaibiotic trichogin GA IV, mono-labeled with 4-cyano-α-methyl-L-phenylalanine, a potentially useful fluorescence and IR absorption probe of the local microenvironment, were synthesized by the solid-phase methodology and conformationally characterized. The single modification was incorporated either at the N-terminus (position 1) or near the C-terminus (position 8) of the peptide main chain. In both cases, the replaced amino acid was the equally helicogenic α-aminoisobutyric acid (Aib) residue. We performed a solution conformational analysis by use of FT-IR absorption, CD, and 2D-NMR spectroscopies. The results indicate that both labeled analogs essentially maintain the overall helical propensity of the naturally occurring lipopeptaibiotic. Peptide-membrane interactions were assessed by fluorescence and ATR-IR absorption techniques. Analogies and differences between the two peptides were highlighted. Taken together, our data confirm literature results that some of the spectroscopic parameters of the 4-cyanobenzyl chromophore are sensitive markers of the local microenvironment.

  9. Spectroscopic and structural investigation on intermediates species structurally associated to the tricyclic bisguanidine compound and to the toxic agent, saxitoxin

    Science.gov (United States)

    Romani, Davide; Tsuchiya, Shigeki; Yotsu-Yamashita, Mari; Brandán, Silvia Antonia

    2016-09-01

    In the present work, we have studied the structural, topological and spectroscopic properties of five cyclic and of open chain species derived from tricyclic bisguanidine compound in gas and aqueous phases combining the DFT calculations with the experimental infrared and 1H NMR, 13C NMR and UV-visible spectra. These species are members of the saxitoxin family and they were recently synthesized by Tsuchiya et al. (Chemistry. A European Journal, 21 (2015) 7835-7840). Here, the self consistent reaction force (SCRF) calculations were employed in aqueous medium to study the solvation energies by using the polarized continuum (PCM) and solvation (SM) models. All the calculations were performed with the 6-31G* and 6-311++G** basis sets. The atomic charges, electrostatic potentials, bond order, stabilization energy, topological properties suggest the structural connection between the cyclic cationic and saxitoxin species while the electrophilicity and nucleophilicity indexes could be one of the explanations for the Nav blocking activities of these species. The complete vibrational assignments for all the species are reported. The predicted spectra present a reasonable concordance with the corresponding experimental ones.

  10. A new combined nuclear magnetic resonance and Raman spectroscopic probe applied to in situ investigations of catalysts and catalytic processes

    Energy Technology Data Exchange (ETDEWEB)

    Camp, Jules C. J.; Mantle, Michael D. [Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA (United Kingdom); York, Andrew P. E. [Johnson Matthey Technology Centre, Blounts Court, Sonning Common, Reading RG4 9NH (United Kingdom); McGregor, James, E-mail: james.mcgregor@sheffield.ac.uk [Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom)

    2014-06-15

    Both Raman and nuclear magnetic resonance (NMR) spectroscopies are valuable analytical techniques capable of providing mechanistic information and thereby providing insights into chemical processes, including catalytic reactions. Since both techniques are chemically sensitive, they yield not only structural information but also quantitative analysis. In this work, for the first time, the combination of the two techniques in a single experimental apparatus is reported. This entailed the design of a new experimental probe capable of recording simultaneous measurements on the same sample and/or system of interest. The individual datasets acquired by each spectroscopic method are compared to their unmodified, stand-alone equivalents on a single sample as a means to benchmark this novel piece of equipment. The application towards monitoring reaction progress is demonstrated through the evolution of the homogeneous catalysed metathesis of 1‑hexene, with both experimental techniques able to detect reactant consumption and product evolution. This is extended by inclusion of magic angle spinning (MAS) NMR capabilities with a custom made MAS 7 mm rotor capable of spinning speeds up to 1600 Hz, quantified by analysis of the spinning sidebands of a sample of KBr. The value of this is demonstrated through an application involving heterogeneous catalysis, namely the metathesis of 2-pentene and ethene. This provides the added benefit of being able to monitor both the reaction progress (by NMR spectroscopy) and also the structure of the catalyst (by Raman spectroscopy) on the very same sample, facilitating the development of structure-performance relationships.

  11. Spectroscopic investigation of the chemical and electronic properties of chalcogenide materials for thin-film optoelectronic devices

    Science.gov (United States)

    Horsley, Kimberly Anne

    Chalcogen-based materials are at the forefront of technologies for sustainable energy production. This progress has come only from decades of research, and further investigation is needed to continue improvement of these materials. For this dissertation, a number of chalcogenide systems were studied, which have applications in optoelectronic devices, such as LEDs and Photovoltaics. The systems studied include Cu(In,Ga)Se2 (CIGSe) and CuInSe 2 (CISe) thin-film absorbers, CdTe-based photovoltaic structures, and CdTe-ZnO nanocomposite materials. For each project, a sample set was prepared through collaboration with outside institutions, and a suite of spectroscopy techniques was employed to answer specific questions about the system. These techniques enabled the investigation of the chemical and electronic structure of the materials, both at the surface and towards the bulk. CdS/Cu(In,Ga)Se2 thin-films produced from the roll-to-roll, ambient pressure, Nanosolar industrial line were studied. While record-breaking efficiency cells are usually prepared in high-vacuum (HV) or ultra-high vacuum (UHV) environments, these samples demonstrate competitive mass-production efficiency without the high-cost deposition environment. We found relatively low levels of C contaminants, limited Na and Se oxidation, and a S-Se intermixing at the CdS/CIGSe interface. The surface band gap compared closely to previously investigated CIGSe thin-films deposited under vacuum, illustrating that roll-to-roll processing is a promising and less-expensive alternative for solar cell production. An alternative deposition process for CuInSe2 was also studied, in collaboration with the University of Luxembourg. CuInSe2 absorbers were prepared with varying Cu content and surface treatments to investigate the potential to produce an absorber with a Cu-rich bulk and Cu-poor surface. This is desired to combine the bulk characteristics of reduced defects and larger grains in Cu-rich films, while maintaining

  12. Investigations on analytic potential energy function, spectroscopic parameters and vibrational manifolds (J = 0) of the SD+(X3∑-) ion

    Institute of Scientific and Technical Information of China (English)

    Zhang Jin-Ping; Shi De-Heng; Sun Jin-Feng; Liu Yu-Fang; Zhu Zun-Lue; Ma Heng

    2009-01-01

    This paper investigates the spectroscopic properties of the SD+(X3∑-) ion by employing the coupled-cluster singles-doublcs-approximate-triples [CCSD(T)] theory combining with the quintuple correlation-consistent basis set augmented with diffuse functions (aug-cc-pV5Z) of Dunning and co-workers. The accurate adiabatic potential energy function is obtained by the least-squares fitting method with the 100 ab initio points, which are calculated at the unrestricted CCSD(T)/aug-cc-pV5Z lcvcl of theory over the internuclear separation range from 0.09 to 2.46 nm. Using the potential, it accurately determines the spectroscopic parameters (De, ωeχe, αe and Be). The prcsent De, Re, ωe,ωeχe,αe and Be results are of 3.69119 eV, 0.13644nm, 1834.949cm-1, 25.6208cm-1, 0.1068cm-1 and 4.7778cm-1,respectively, which are in remarkably good agreement with the experimental findings. A total of 29 vibrational states has been predicted by numerically solving the radial Schrodinger equation of nuclear motion when the rotational quantum number J equals zero. The complete vibrational levels, classical turning points, inertial rotation and centrifugal distortion constants are reported when J = 0 for the first time, which are in good accord with the measurements wherever available.

  13. Investigation of the Spectroscopic Information on Functional Groups Related to Carbohydrates in Different Morphological Fractions of Corn Stover and Their Relationship to Nutrient Supply and Biodegradation Characteristics.

    Science.gov (United States)

    Xin, Hangshu; Ding, Xue; Zhang, Liyang; Sun, Fang; Wang, Xiaofan; Zhang, Yonggen

    2017-05-24

    The objectives of this study were to investigate (1) nutritive values and biodegradation characteristics and (2) mid-IR spectroscopic features within the regions associated with carbohydrate functional groups (including cellulosic component (CELC), structural carbohydrate (STCHO), and total carbohydrate (CHO)) in different morphological fractions of corn stover. Furthermore, correlation and regression analyses were also applied to determine the relationship between nutritional values and spectroscopic parameters. The results showed that different morphological sections of corn stover had different nutrient supplies, in situ biodegradation characteristics, and spectral structural features within carbohydrate regions. The stem rind and ear husk were both high in fibrous content, which led to the lowest effective degradabilities (ED) among these stalk fractions. The ED values of NDF were ranked ear husk > stem pith > leaf blade > leaf sheath > whole plant > stem rind. Intensities of peak height and area within carbohydrate regions were relatively more stable compared with spectral ratio profiles. Significant difference was found only in peak area intensity of CELC, which was at the highest level for stem rind, followed by stem pith, leaf sheath, whole plant, leaf blade, and ear husk. Correlation results showed that changes in some carbohydrate spectral ratios were highly associated with carbohydrate chemical profiles and in situ rumen degradation kinetics. Among the various carbohydrate molecular spectral parameters that were tested in multiple regression analysis, CHO height ratios, and area ratios of CELC:CHO and CELC:STCHO as well as CELC area were mostly sensitive to nutrient supply and biodegradation characteristics in different morphological fractions of corn stover.

  14. Investigation of Bovine Serum Albumin (BSA Attachment onto Self-Assembled Monolayers (SAMs Using Combinatorial Quartz Crystal Microbalance with Dissipation (QCM-D and Spectroscopic Ellipsometry (SE.

    Directory of Open Access Journals (Sweden)

    Hanh T M Phan

    Full Text Available Understanding protein adsorption kinetics to surfaces is of importance for various environmental and biomedical applications. Adsorption of bovine serum albumin to various self-assembled monolayer surfaces including neutral and charged hydrophilic and hydrophobic surfaces was investigated using in-situ combinatorial quartz crystal microbalance with dissipation and spectroscopic ellipsometry. Adsorption of bovine serum albumin varied as a function of surface properties, bovine serum albumin concentration and pH value. Charged surfaces exhibited a greater quantity of bovine serum albumin adsorption, a larger bovine serum albumin layer thickness, and increased density of bovine serum albumin protein compared to neutral surfaces at neutral pH value. The quantity of adsorbed bovine serum albumin protein increased with increasing bovine serum albumin concentration. After equilibrium sorption was reached at pH 7.0, desorption of bovine serum albumin occurred when pH was lowered to 2.0, which is below the isoelectric point of bovine serum albumin. Our data provide further evidence that combinatorial quartz crystal microbalance with dissipation and spectroscopic ellipsometry is a sensitive analytical tool to evaluate attachment and detachment of adsorbed proteins in systems with environmental implications.

  15. Investigating the effect of Phlomis lanceolata Boiss and hohen on cancer cell lines.

    Directory of Open Access Journals (Sweden)

    Farnaz Soltani-Nasab

    2014-05-01

    Full Text Available Phlomis lanceolata is a medicinal plant that has long been used to treat various conditions such as diabetes, gastric ulcer, hemorrhoids, inflammation and wounds. As most of Phlomis species have shown cytotoxic activity against proliferation of different cell lines, a biological investigation of P. lanceolata was carried out in this study. The aim of this study was to find out the in vitro cytotoxic activity of total extract and different fractions of Phlomis lanceolata on four cell lines. Cytotoxic activity of the metanolic total extract and partition fractions of chloroform, ethyl acetate and petroleum ether of flowering aerial parts of Phlomis lanceolata on the HT29, Caco2, T47D and NIH3T3 cell lines is examined by MTT. Petroleum ether fraction showed high cytotoxic activity against proliferation of all four cell lines. Presence of heavy triterpens and lipophil compounds recognized by TLC test in Petroleum ether fraction is responsible for high cytotoxic activity. The results emphasize the importance of phytochemical studies which could lead to the discovery of new active compounds.

  16. NIR spectroscopic method for the in-line moisture assessment during drying in a six-segmented fluid bed dryer of a continuous tablet production line: Validation of quantifying abilities and uncertainty assessment.

    Science.gov (United States)

    Fonteyne, Margot; Arruabarrena, Julen; de Beer, Jacques; Hellings, Mario; Van Den Kerkhof, Tom; Burggraeve, Anneleen; Vervaet, Chris; Remon, Jean Paul; De Beer, Thomas

    2014-11-01

    This study focuses on the thorough validation of an in-line NIR based moisture quantification method in the six-segmented fluid bed dryer of a continuous from-powder-to-tablet manufacturing line (ConsiGma™ 25, GEA Pharma Systems nv, Wommelgem, Belgium). The moisture assessment ability of an FT-NIR spectrometer (Matrix™-F Duplex, Bruker Optics Ltd, UK) equipped with a fiber-optic Lighthouse Probe™ (LHP, GEA Pharma Systems nv, Wommelgem, Belgium) was investigated. Although NIR spectroscopy is a widely used technique for in-process moisture determination, a minority of NIR spectroscopy methods is thoroughly validated. A moisture quantification PLS model was developed. Twenty calibration experiments were conducted, during which spectra were collected at-line and then regressed versus the corresponding residual moisture values obtained via Karl Fischer measurements. The developed NIR moisture quantification model was then validated by calculating the accuracy profiles on the basis of the analysis results of independent in-line validation experiments. Furthermore, as the aim of the NIR method is to replace the destructive, time-consuming Karl Fischer titration, it was statistically demonstrated that the new NIR method performs at least as good as the Karl Fischer reference method.

  17. Investigation of the behavior of protection elements against field radiated line coupled UWB-pulses

    Directory of Open Access Journals (Sweden)

    R. Krzikalla

    2006-01-01

    Full Text Available To protect electronic systems against electromagnetic interferences in general nonlinear protection circuits are used. These protection circuits are optimized mostly against special transient interferences such as lightning electromagnetic pulses (LEMP or electromagnetic pulses caused by nuclear explosions (NEMP. Previous investigations have shown that these protection elements could be undermined by so-called ultra wideband (UWB pulses. Thereby a direct charge of the UWB-pulse to the elements has been assumed. This assumption was a worst case approximation because in practice UWB-pulses only get into systems by coupling effects. In this investigation the behavior of typical nonlinear protection elements has been tested with field radiated line coupled UWB-pulses. For that line coupled UWB-pulses have been defined depending on the coupling behavior of typical electronic systems and a possibility of generation of this kind of pulses is presented. After it typical nonlinear protection elements such as spark gaps, varistors and protection diodes have been tested with the previously defined test pulses. Finally the measured behavior of the elements has been compared with the behavior by direct charged UWB-pulses and the protection effect of the elements against field radiated line coupled UWB-pulses is re-evaluated.

  18. A comparison investigation of DNP-binding effects to HSA and HTF by spectroscopic and molecular modeling techniques.

    Science.gov (United States)

    Zolfagharzadeh, Mahboobeh; Pirouzi, Maliheh; Asoodeh, Ahmad; Saberi, Mohammad Reza; Chamani, Jamshidkhan

    2014-12-01

    This paper describes the interaction between 2,4-dinitrophenol (DNP) with the two drug carrier proteins - human serum albumin (HSA) and human holo transferrin (HTF). Hence, binding characteristics of DNP to HSA and HTF were analyzed by spectroscopic and molecular modeling techniques. Based on results obtained from fluorescence spectroscopy, DNP had a strong ability to quench the intrinsic fluorescence of HSA and HTF through a static quenching procedure. The binding constant and the number of binding sites were calculated as 2.3 × 10(11) M(-1) and .98 for HSA, and 1.7 × 10(11) M(-1) and 1.06 for HTF, respectively. In addition, synchronous fluorescence results showed that the microenvironment of Trp had a slight tendency of increasing its hydrophobicity, whereas the microenvironment of the Tyr residues of HSA did not change and that of HTF showed a significant trend (red shift of about 4 nm) of an increase in polarity. The distance between donor and acceptor was obtained by the Förster energy according to fluorescence resonance energy transfer, and was found to be 3.99 and 3.72 nm for HSA and HTF, respectively. The critical induced aggregation concentration (CCIAC) of the drug on both proteins was determined and confirmed by an inflection point of the zeta potential behavior. Circular dichroism data revealed that the presence of DNP caused a decrease of the α-helical content of HSA and HTF, and induced a remarkable mild denaturation of both proteins. The molecular modeling data confirmed our experimental results. This study is deemed useful for determining drug dosage.

  19. 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 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.

  20. Zeeman effect of weak La I lines investigated by the use of optogalvanic spectroscopy

    Science.gov (United States)

    Sobolewski, Ł. M.; Windholz, L.; Kwela, J.

    2017-03-01

    New Landé- gJ factors of 35 energy levels of La I, found from investigations of 40 spectral lines in the wavelength range 562.959÷609.537 nm, were determined. As a source of free La atoms a hollow cathode discharge lamp was used. We monitored the signal of the optogalvanic effect appearing when a laser beam is passing through the hollow cathode. Spectra were recorded in the presence of a magnetic field of about 800 G produced by a permanent magnet, for two linear polarizations of the exciting laser light. Optogalvanic spectroscopy is a very sensitive method, so we were able to observe the Zeeman effect of very weak atomic lines. In this way we have determined for the first time the Landé-gJ factors for 35 recently found levels of neutral La. The Landé gJ- factors for several other levels were reinvestigated.

  1. Bio-important antipyrine derived Schiff bases and their transition metal complexes: Synthesis, spectroscopic characterization, antimicrobial, anthelmintic and DNA cleavage investigation

    Science.gov (United States)

    Manjunath, M.; Kulkarni, Ajaykumar D.; Bagihalli, Gangadhar B.; Malladi, Shridhar; Patil, Sangamesh A.

    2017-01-01

    Spectroscopic (IR, NMR, UV-vis, ESR, ESI-mass), magnetic and TGA studies suggests octahedral geometry for all the CoII, NiII and CuII complexes of the Schiff bases, derived from 4-aminoantipyrine and 8-formyl-7-Hydroxy-4-methylcoumarin/5-formyl-6-hydroxycoumarin, coordinated through ONO donor sites. Antibacterial (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi), antifungal (Aspergillus niger, Aspergillus flavus and Cladosporium) and DNA cleavage properties of the metal complexes are investigated. The results suggested that some of the synthesized compounds are potential antimicrobials. The synthesized compounds tested for their anthelmintic activities and it was found that CoII and NiII complexes exhibited good anthelmintic properties.

  2. Efficient synthesis of metallated thioporphyrazines in task specific ionic liquids and their spectroscopic investigation of binding with selected transition metal ions

    Indian Academy of Sciences (India)

    POONAM; RITIKA NAGPAL; SMRITI ARORA; SHIVE M S CHAUHAN

    2016-09-01

    Tetramerization of substituted maleonitriles in task specific 2-hydroxylethyl based imidazolium ionic liquids at 120◦C gave corresponding electron rich peripheral substituted thioporphyrazines in moderate yield. The 2-hydroxylethyl imidazolium ionic liquids gave better yields of peripheral substituted thioporphyrazinesin comparison with non-hydroxyl functionalized ionic liquids. Further, these peripherally functionalized porphyrazines containing sulphur are used to investigate spectroscopically the binding studies with palladium(II) and mercury(II) ions. These metal ions are toxic in nature and deserve serious attention in the areaof design of effective separation and efficient micro-sensing techniques. The UV–Vis absorption spectroscopy and fluorescence signalling are mainly used to study peripheral binding of transition metal ions.

  3. Investigation on Acute Biochemical Effects of Ce(NO3)3 on Liver and Kidney Tissues by MAS 1H NMR Spectroscopic-Based Metabonomic Approach

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    High resolution magic angle spinning (MAS)-1 H nuclear magnetic resonance (NMR) spectroscopic-based metabonomic approach was applied to the investigation on the acute biochemical effects of Ce(NO3)3. Male Wistar rats were liver and kidney tissues were analyzed using principal component analysis to extract toxicity information. The biochemical effects of Ce(NO3)3 were characterized by the increase of triglycerides and lactate and the decrease of glycogen in rat liver tissue, together with an elevation of the triglyceride level and a depletion of glycerophosphocholine and betaine in kidney tissues. The target lesions of Ce(NO3)3 on liver and kidney were found by MAS NMR-based metabonomic method. This study demonstrates that the combination of MAS 1H NMR and pattern recognition analysis can be an effective method for studies of biochemical effects of rare earths.

  4. Spectroscopic investigation on kinetics, thermodynamics and mechanism for electron transfer reaction of iron(III) complex with sulphur centered radical in stimulated biological system.

    Science.gov (United States)

    Deepalakshmi, S; Sivalingam, A; Kannadasan, T; Subramaniam, P; Sivakumar, P; Brahadeesh, S T

    2014-04-24

    Electron transfer reactions of biological organic sulphides with several metal ions to generate sulphide radical cations are a great concern in biochemical process. To understand the mechanism, a stimulated biological system having model compounds, iron(III)-bipyridyl complex with thio-diglycolic acid (TDGA) was investigated. Spectroscopic study reveals the kinetics and thermodynamics of the reaction in aqueous perchloric acid medium. The reaction follows first and fractional order of 0.412 with respect to [Fe(bpy)3](3+) and TDGA, respectively. The oxidation is insensitive to variation in [H(+)] but slightly decreases with increase in ionic strength ([I]). Addition of acrylamide, a radical scavenger has no effect on the rate of the reaction. The high negative value of ΔS(#) (-74.3±1.09 J K(-1) mol(-1)) indicates the complex formed has a definite orientation higher than the reactants. Based on the above results, a suitable reaction mechanism for this reaction is proposed.

  5. Spectroscopic investigation into the interaction of a diazacyclam-based macrocyclic copper(ii) complex with bovine serum albumin.

    Science.gov (United States)

    Shahabadi, Nahid; Hakimi, Mohammad; Morovati, Teimoor; Hadidi, Saba; Moeini, Keyvan

    2017-02-01

    Cyclam-based ligands and their complexes are known to show antitumor activity. This study was undertaken to examine the interaction of a diazacyclam-based macrocyclic copper(II) complex with bovine serum albumin (BSA) under physiological conditions. The interactions of different metal-based drugs with blood proteins, especially those with serum albumin, may affect the concentration and deactivation of metal drugs, and thereby influence their availability and toxicity during chemotherapy. In this vein, several spectral methods including UV-vis absorption, fluorescence and circular dichroism (CD) spectroscopy techniques were used. Spectroscopic analysis of the fluorescence quenching confirmed that the Cu(II) complex quenched BSA fluorescence intensity by a dynamic mechanism. In order to further determine the quenching mechanism, an analysis of Stern-Volmer plots at various concentrations of BSA was carried out. It was found that the KSV value increased with the BSA concentration. It was suggested that the fluorescence quenching process was a dynamic quenching rather than a static quenching mechanism. Based on Förster's theory, the average binding distance between the Cu(II) complex and BSA (r) was found to be 4.98 nm; as the binding distance was less than 8 nm, energy transfer from BSA to the Cu(II) complex had a high possibility of occurrence. Thermodynamic parameters (positive ΔH and ΔS values) and measurement of competitive fluorescence with 1-anilinonaphthalene-8-sulphonic acid (1,8-ANS) indicated that hydrophobic interaction plays a major role in the Cu(II) complex interaction with BSA. A Job's plot of the results confirmed that there was one binding site in BSA for the Cu(II) complex (1:1 stoichiometry). The site marker competitive experiment confirmed that the Cu(II) complex was located in site I (subdomain IIA) of BSA. Finally, CD data indicated that interaction of the Cu(II) complex with BSA caused a small increase in the α-helical content. Copyright

  6. Spectroscopic investigations of Gd3Sc2Ga3O12 garnet doped with Cr3+ and Nd3+ ions

    Institute of Scientific and Technical Information of China (English)

    K.Lema(n)ski; P.J.Dere(n); A.Gagor; W.Strek

    2009-01-01

    Absorption,excitation and emission spectra as well as decay time measurements at 10,77,and 300 K were performed for Ga3Gd3Sc2O12 garnet single-crystal doped with Cr3+ and Nd3+ ions.Strong reabsorption of Cr3+ emission by Nd3+ absorption lines was observed.The assignments of f-f and d-d transitions were proposed.The broad emission band of chromium ions is an indication that weak/intermediate crystal field strength is present at the Cr3+ site.

  7. Investigation on False Peak Phenomena in On-line Sweeping Technique in MEKC

    Institute of Scientific and Technical Information of China (English)

    YANG,Geng-Liang(杨更亮); LI,Bao-Hui(李保会); WANG,De-Xian(王德先); CHEN,Yi(陈义)

    2002-01-01

    In this paper, several factors that could lead to the appearance of false peak were investigated by using on-line sample sweeping technique under different experimental conditions. The tested analytes were buflomedil hydrochloride, ephedrine hydrochloride, benzyl alcohol, vanillin, p-hydroxybenzaldehyde amd mmethylphenol. Results showed that among the six compounds,three of them, i.e., buflomedil hydrochloride, ephedrine hydrochloride and benzyl alcohol will cause false peaks to appear when sample injection time is long, sodium dodecyl sulfate (SDS) concentration is high and there is pH gradient between cathode and anode. In order to avoid the appearance of false peak, the pH gradient should be avoided.

  8. Investigation of Cytocidal Activity of Bacillus Thuringiensis Parasporal Toxin on CCRF-CEM Cell Line

    Directory of Open Access Journals (Sweden)

    Elham Moazamian

    2013-03-01

    Full Text Available Background & Objective: Parasporin is a parasporal protein of Bacillus thuringiensis and exhibits special cytocidal activity against human cancer cells. Similar to other insecticidal Bacillus thuringiensis crystal toxins, parasporin shows target specificity and damages the cellular membrane. In this study, different strains of Bacillus thuringiensis isolated from various regions of Iran and their cytocidal activity against CCRF-CEM cell line and human erythrocyte were investigated.   Materials & Methods: Fifty soil samples were collected from different Iranian provinces, and characterization was performed based on protein crystal morphology by phase-contrast microscope and variations of Cry protein toxin using SDS-PAGE. After parasporin was processed with proteinase K, the active form was produced and protein activity on the cell line was evaluated. Results: Parasporal inclusion proteins showed different cytotoxicity against acute lymphoblastic leukemia cells (ALL, but not against normal lymphocyte. Isolated parasporin demonstrated no hemolytic activity against human erythrocyte. It appears that these proteins have the ability to differentiate between normal lymphocytes and leukemia cells and have specific receptors on specific cancer cell lines. Conclusion: Our results provide evidence that the parasporin-producing organism is a common member in Bacillus thuringiensis populations occurring in the natural environments of Iran.

  9. 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.

  10. Crystal structure, magnetism, {sup 89}Y solid state NMR, and {sup 121}Sb Moessbauer spectroscopic investigations of YIrSb

    Energy Technology Data Exchange (ETDEWEB)

    Benndorf, Christopher [Institut fuer Physikalische Chemie, Universitaet Muenster (Germany); Institut fuer Anorganische und Analytische Chemie, Universitaet Muenster (Germany); Heletta, Lukas; Block, Theresa; Poettgen, Rainer [Institut fuer Anorganische und Analytische Chemie, Universitaet Muenster (Germany); Eckert, Hellmut [Institut fuer Physikalische Chemie, Universitaet Muenster (Germany); Institute of Physics in Sao Carlos, University of Sao Paulo, Sao Carlos (Brazil)

    2017-02-15

    The ternary antimonide YIrSb was synthesized from the binary precursor YIr and elemental antimony by a diffusion controlled solid-state reaction. Single crystals were obtained by a flux technique with elemental bismuth as an inert solvent. The YIrSb structure (TiNiSi type, space group Pnma) was refined from single-crystal X-ray diffractometer data: a = 711.06(9), b = 447.74(5), c = 784.20(8) pm, wR{sub 2} = 0.0455, 535 F{sup 2} values, 20 variables. {sup 89}Y solid state MAS NMR and {sup 121}Sb Moessbauer spectra show single resonance lines in agreement with single-crystal X-ray data. YIrSb is a Pauli paramagnet. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Radial velocities of giant stars: an investigation of line profile variations

    Energy Technology Data Exchange (ETDEWEB)

    Hekker, S; Snellen, I A G [Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden (Netherlands); Aerts, C [Instituut voor Sterrenkunde, KU Leuven, Celestijnenlaan 200D, 3001 Leuven (Belgium); Quirrenbach, A; Reffert, S [ZAH, Landessternwarte Heidelberg, Koenigstuhl 12, D-69117 Heidelberg (Germany); Mitchell, D S [California Polytechnic State University, San Luis Obispo, CA 93407 (United States)], E-mail: saskia@strw.leidenuniv.nl

    2008-10-15

    Since 1999, a radial velocity survey of 179 red giant stars is ongoing at Lick Observatory with a one month cadence. At present{approx}20-100 measurements have been collected per star with an accuracy of 5 to 8 ms{sup -1}. Of the stars monitored, 145 (80%) show radial velocity (RV) variations at a level >20 ms{sup -1}, of which 43 exhibit significant periodicities. Here, we investigate the mechanism causing the observed radial velocity variations. Firstly, we search for a correlation between the radial velocity amplitude and an intrinsic parameter of the star, in this case surface gravity (logg). Secondly, we investigate line profile variations and compare these with theoretical predictions.

  12. Circular dichroism spectroscopic investigation of double-decker phthalocyanine with G-Quadruplex as promising telomerase inhibitor

    Science.gov (United States)

    Baǧda, Efkan; Baǧda, Esra; Yabaş, Ebru

    2017-01-01

    In the present study, interaction of a double-decker phthalocyanine with two G-quadruplex DNA, Tel 21 and cMYC, was investigated. To the best of our knowledge, this is the first study about G-quadruplex-double decker phthalocyanine interaction. The spectrophotometric titration method was used for binding constant calculations. From the binding constants, it can be said that double-decker phthalocyanine more likely to bind Tel 21 rather than cMYC. The conformational changes upon binding were monitored via circular dichroism spectroscopy. The ethidium bromide replacement assay was investigated spectrofluorometrically.

  13. Spectroscopic and time-dependent density functional theory investigation of the photophysical properties of zearalenone and its analogs

    Science.gov (United States)

    Structures of the mycotoxin zearalenone and its analogs were investigated using density functional theory methods to gain insight into the ground state and excited state properties related to detection. Zearalenone is an estrogenic mycotoxin that can occur in agricultural commodities, and ultraviole...

  14. Spectroscopic investigations of dark Si nanocrystals in SiO2 and their role in external quantum efficiency quenching"

    NARCIS (Netherlands)

    Limpens, R.; Gregorkiewicz, T.

    2013-01-01

    The percentage of dark silicon nanocrystals, i.e., the nanocrystals that are not able to radiatively recombine after absorption of a photon, is investigated by combining measurements of external and internal quantum efficiencies. The study is conducted on samples prepared by co-sputtering and subseq

  15. Electrochemical and spectroscopic investigations of uranium(III) with N,N,N',N'-tetramethylmalonamide in DMF

    Energy Technology Data Exchange (ETDEWEB)

    Yamamura, T. [Institute for Materials Research, Tohoku University, Sendai, Miyagi 980-8577 (Japan)]. E-mail: yamamura@imr.tohoku.ac.jp; Shirasaki, K. [Institute for Materials Research, Tohoku University, Sendai, Miyagi 980-8577 (Japan); Li, D.X. [Institute for Materials Research, Tohoku University, Sendai, Miyagi 980-8577 (Japan); Shiokawa, Y. [Institute for Materials Research, Tohoku University, Sendai, Miyagi 980-8577 (Japan)

    2006-07-20

    In order to investigate the electrode reaction of negative electrolyte, U(III)/U(IV), of the all-uranium redox-flow battery proposed by us, we investigated the magnetic susceptibility, spectroscopy and electrode reactions of U(III) and U(IV) complexes with N,N,N',N'-tetramethylmalonamide (TMMA). The effective magnetic moment for the U(III) complex (1.95{mu} {sub B}/atomU) is significantly smaller than the theoretical moment for free U{sup 3+} ion, and this may indicate the itinerant nature of U(III) due to the coordination of TMMA. In N,N-dimethylformamide (DMF), the energy levels due to f-f transitions was only slightly perturbed from those of uranium(III) perchlorate in DMF. The U(III)/U(IV) redox potential of U(III)-TMMA complex shifted negatively from that of uranium(III) perchlorate.

  16. Spectroscopic and catalytic investigations of VxOy/SBA-15 and magnesium vanadate model catalysts for selective propene oxidation

    OpenAIRE

    Walter, Anke

    2011-01-01

    The objective of the present work was elucidating structure-activity relationships concerning the individual role of vanadium sites in selective propene oxidation. Two suitable vanadium oxide model catalyst systems were employed: vanadium oxides supported on SBA-15, “VxOy/SBA-15”, and various magnesium vanadate phases. Detailed investigations on the preparation, thermal stability, structure, and structural evolution under reducing and propene oxidizing condition were conducted. Various in sit...

  17. UV–Vis and ATR–FTIR spectroscopic investigations of postmortem interval based on the changes in rabbit plasma

    Science.gov (United States)

    Wang, Qi; He, Haijun; Li, Bing; Lin, Hancheng; Zhang, Yinming; Zhang, Ji

    2017-01-01

    Estimating PMI is of great importance in forensic investigations. Although many methods are used to estimate the PMI, a few investigations focus on the postmortem redistribution. In this study, ultraviolet–visible (UV–Vis) measurement combined with visual inspection indicated a regular diffusion of hemoglobin into plasma after death showing the redistribution of postmortem components in blood. Thereafter, attenuated total reflection–Fourier transform infrared (ATR–FTIR) spectroscopy was used to confirm the variations caused by this phenomenon. First, full-spectrum partial least-squares (PLS) and genetic algorithm combined with PLS (GA-PLS) models were constructed to predict the PMI. The performance of GA-PLS model was better than that of full-spectrum PLS model based on its root mean square error (RMSE) of cross-validation of 3.46 h (R2 = 0.95) and the RMSE of prediction of 3.46 h (R2 = 0.94). The investigation on the similarity of spectra between blood plasma and formed elements also supported the role of redistribution of components in spectral changes in postmortem plasma. These results demonstrated that ATR-FTIR spectroscopy coupled with the advanced mathematical methods could serve as a convenient and reliable tool to study the redistribution of postmortem components and estimate the PMI. PMID:28753641

  18. Spectroscopic investigation of Er{sup 3+} in fluorotellurite glasses for 2.7 μm luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Feng; Bi, Zhuanfang; Chen, Jiayang; Huang, Anping [Key Laboratory of Micro-nano Measurement, Manipulation and Physics (Ministry of Education), School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China); Zhu, Yongchang [China Building Materials Academy, Beijing, 100024 (China); Chen, Baojie [Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Xiao, Zhisong, E-mail: zsxiao@buaa.edu.cn [Key Laboratory of Micro-nano Measurement, Manipulation and Physics (Ministry of Education), School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China)

    2015-11-15

    Er{sup 3+} doped fluorotellurite glass (TeO{sub 2}–BaF{sub 2}–NaF) with different Er{sup 3+} concentrations were prepared, glass thermal stability and structure were investigated by differential scanning calorimetry (DSC) test and Raman spectrum, respectively. 2.7 μm light emission was observed under 980 nm excitation in these fluorotellurite glasses. The 2.7 μm emission properties were investigated through the measured absorption and emission spectra. The spontaneous transition probability (A), branching ratio (β), emission and absorption cross sections were calculated and the values were relatively larger than some reported values, which indicated that this kind of fluorotellurite glass has potential application as host material for 2.7 μm lasers. - Highlights: • High T{sub g} (375 °C) provides good thermal stability to resist thermal damage. • The introduction of F{sup −} decreases the connectivity of the tellurite former network. • Er{sup 3+} doped TBN glasses have been investigated using Judd–Ofelt (JO) theory. • TBN glasses possess high stimulated emission cross section σ{sub e} for 2.7 μm emission.

  19. Spectroscopic investigations on the effect of N-Acetyl-L-cysteine-Capped CdTe Quantum Dots on catalase

    Science.gov (United States)

    Sun, Haoyu; Yang, Bingjun; Cui, Erqian; Liu, Rutao

    2014-11-01

    Quantum dots (QDs) are recognized as some of the most promising semiconductor nanocrystals in biomedical applications. However, the potential toxicity of QDs has aroused wide public concern. Catalase (CAT) is a common enzyme in animal and plant tissues. For the potential application of QDs in vivo, it is important to investigate the interaction of QDs with CAT. In this work, the effect of N-Acetyl-L-cysteine-Capped CdTe Quantum Dots with fluorescence emission peak at 612 nm (QDs-612) on CAT was investigated by fluorescence, synchronous fluorescence, fluorescence lifetime, ultraviolet-visible (UV-vis) absorption and circular dichroism (CD) techniques. Binding of QDs-612 to CAT caused static quenching of the fluorescence, the change of the secondary structure of CAT and the alteration of the microenvironment of tryptophan residues. The association constants K were determined to be K288K = 7.98 × 105 L mol-1 and K298K = 7.21 × 105 L mol-1. The interaction between QDs-612 and CAT was spontaneous with 1:1 stoichiometry approximately. The CAT activity was also inhibited for the bound QDs-612. This work provides direct evidence about enzyme toxicity of QDs-612 to CAT in vitro and establishes a new strategy to investigate the interaction between enzyme and QDs at a molecular level, which is helpful for clarifying the bioactivities of QDs in vivo.

  20. A Numerical Investigation of a Slow-Moving Convective Line in a Weakly Sheared Environment

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A series of three-dimensional, cloud-resolving numerical simulations are performed to examine a slowpropagating, quasi-two-dimensional convective system in a weakly sheared environment during the Tropical Rainfall Measuring Mission Large-Scale Biosphere-Atmosphere (TRMM-LBA) field campaign. The focus is on the kinematics and thermodynamics, organization mechanisms, and dynamical effects of low-level shear, ice microphysics and tropospheric humidity. The control simulation, which is initialized with the observed sounding and includes full microphysics, successfully replicates many observed features of the convective system, such as the linear structure, spatial orientation, life cycle, and sluggish translation.The system at the mature stage displays a line-normal structure similar to that associated with squalltype convective systems, but the corresponding mesoscale circulation and thermodynamic modification are much weaker. Ice-phase microphysical processes are not necessary to the formation of the convective system, but they play a non-trivial role in the late evolution stage. In contrast, the low-level shear, albeit shallow and weak, is critical to the realistic realization of the convective line. The tropospheric moisture above the planetary boundary layer has an important impact on the behavior of convective organization.In particular, a dry layer in the lower troposphere significantly suppresses convective development and inhibits the generation of organized convection even though the convective available potential energy is substantial. The free-atmosphere humidity has received little attention in previous studies of organized convection and warrants further investigation.

  1. THE NASA AMES PAH IR SPECTROSCOPIC DATABASE VERSION 2.00: UPDATED CONTENT, WEB SITE, AND ON(OFF)LINE TOOLS

    Energy Technology Data Exchange (ETDEWEB)

    Boersma, C.; Mattioda, A. L.; Allamandola, L. J. [NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035 (United States); Bauschlicher, C. W. Jr.; Ricca, A. [NASA Ames Research Center, MS 230-3, Moffett Field, CA 94035 (United States); Cami, J.; Peeters, E.; De Armas, F. Sánchez; Saborido, G. Puerta [SETI Institute, 189 Bernardo Avenue 100, Mountain View, CA 94043 (United States); Hudgins, D. M., E-mail: Christiaan.Boersma@nasa.gov [NASA Headquarters, MS 3Y28, 300 E St. SW, Washington, DC 20546 (United States)

    2014-03-01

    A significantly updated version of the NASA Ames PAH IR Spectroscopic Database, the first major revision since its release in 2010, is presented. The current version, version 2.00, contains 700 computational and 75 experimental spectra compared, respectively, with 583 and 60 in the initial release. The spectra span the 2.5-4000 μm (4000-2.5 cm{sup -1}) range. New tools are available on the site that allow one to analyze spectra in the database and compare them with imported astronomical spectra as well as a suite of IDL object classes (a collection of programs utilizing IDL's object-oriented programming capabilities) that permit offline analysis called the AmesPAHdbIDLSuite. Most noteworthy among the additions are the extension of the computational spectroscopic database to include a number of significantly larger polycyclic aromatic hydrocarbons (PAHs), the ability to visualize the molecular atomic motions corresponding to each vibrational mode, and a new tool that allows one to perform a non-negative least-squares fit of an imported astronomical spectrum with PAH spectra in the computational database. Finally, a methodology is described in the Appendix, and implemented using the AmesPAHdbIDLSuite, that allows the user to enforce charge balance during the fitting procedure.

  2. Performance of line-scanning confocal microscopy in human skin: investigation of potential for clinical translation

    Science.gov (United States)

    Larson, Bjorg; Peterson, Gary; Abeytunge, Sanjeewa; Rajadhyaksha, Milind

    2011-03-01

    Line-scanning, using 8-10 optical components, linear-array detectors and custom-FPGA electronics, may enable smaller, simpler and lower-cost confocal microscopes to accelerate translation to the clinic. The adaptability of commercially available low-cost array detectors for confocal microscopy is being investigated. Measurements of optical sectioning and lateral resolution showed good agreement with theory, and are comparable to that of point-scanning systems. LSFs through full thickness of human epidermis show a two-fold degradation in sectioning performance. Imaging of human epidermis in vivo demonstrates nuclear and cellular detail down to the basal layer with a bench top setup and also a compact clinical prototype. Blood flow in oral mucosa can be imaged using the clinical prototype. However, speckle and background noise degrade contrast and resolution of the image.

  3. Structural and spectroscopic investigation on antioxidant dipeptide, L-Methionyl-L-Serine: A combined experimental and DFT study

    Science.gov (United States)

    Kecel-Gunduz, Serda; Bicak, Bilge; Celik, Sefa; Akyuz, Sevim; Ozel, Aysen E.

    2017-06-01

    The focus of this study is to determine the conformational, structural and vibrational properties of Methionyl-Serine dipeptide (L-Methionyl-L-Serine, Met-Ser), a biological active molecule. To investigate their energetically preferred conformations, molecular mechanics methods were utilized to determine the optimal conformations of the 3402 different dihedral angle values of the backbone and side chains. It was found that the extended (e) backbone shape in the LB conformational range was the most stable L-Methionyl-L-Serine dipeptide conformation, with 3.12 kcal/mol of energy. Density Functional Theory (DFT) was used to determine the optimized geometry, the vibrational wavenumbers and modes of the title dipeptide values, with 6-31G (d,p) and 6-311++G (d,p) basis sets. The potential energy distribution data was used to carry out the assignment of the bands. In addition, the vibrational spectra of the most stable conformer and its dimer form were determined and the obtained results were compared with the experimental IR and Raman spectra in the solid phase. To determine the presence of intramolecular charge transfer, molecular dipole moment, polarizability and hyperpolarizability, the Natural Bond Orbital (NBO), HOMO-LUMO calculations, the linear polarizability (α) and the first order hyperpolarizability (β0) value analyses of the investigated molecule were carried out using the DFT with the B3LYP/6-31++G(d,p) basis set. This study aims to determine a relatively stable conformation of antioxidant dipeptide and to investigate the molecular geometry, molecular vibrations and hydrogen bonding interactions between monomeric and dimeric forms of Methiony-Serine dipeptide.

  4. Raman spectroscopic investigation of 13CO 2 labeling and leaf dark respiration of Fagus sylvatica L. (European beech).

    Science.gov (United States)

    Keiner, Robert; Gruselle, Marie-Cécile; Michalzik, Beate; Popp, Jürgen; Frosch, Torsten

    2015-03-01

    An important issue, in times of climate change and more extreme weather events, is the investigation of forest ecosystem reactions to these events. Longer drought periods stress the vitality of trees and promote mass insect outbreaks, which strongly affect ecosystem processes and services. Cavity-enhanced Raman gas spectrometry was applied for online multi-gas analysis of the gas exchange rates of O2 and CO2 and the labeling of Fagus sylvatica L. (European beech) seedlings with (13)CO2. The rapid monitoring of all these gases simultaneously allowed for the separation of photosynthetic uptake of CO2 by the beech seedlings and a constant (12)CO2 efflux via respiration and thus for a correction of the measured (12)CO2 concentrations in course of the labeling experiment. The effects of aphid infestation with the woolly beech aphid (Phyllaphis fagi L.) as well as the effect of a drought period on the respirational gas exchange were investigated. A slightly decreased respirational activity of drought-stressed seedlings in comparison to normally watered seedlings was found already for a low drought intensity. Cavity-enhanced Raman gas monitoring of O2, (12)CO2, and (13)CO2 was proven to be a powerful new tool for studying the effect of drought stress and aphid infestation on the respirational activity of European beech seedlings as an example of important forest species in Central Europe.

  5. FT-IR spectroscopic investigation of ionic interactions in PPG 4000: AgCF3SO3 polymer electrolyte.

    Science.gov (United States)

    Suthanthiraraj, S Austin; Kumar, R; Paul, B Joseph

    2009-01-01

    The effect of salt concentration on the ubiquitous ionic interactions observed in the case of the silver ion conducting polymer electrolyte system poly(propylene glycol) (PPG)-silver triflate has been investigated using Fourier transform infrared (FT-IR) spectroscopy as a probe for the characterization of the local environment of the triflate ion in PPG-based polymer electrolytes. The maximum free anion concentrations of symmetric and asymmetric SO(3) stretching modes in the case of poly(propylene glycol) complexed with silver triflate (AgCF(3)SO(3)) corresponding to the ether oxygen metal cation ratios from 2:1 to 6:1 have been investigated in detail. The present Fourier transform infrared spectral studies of the C-O-C stretching mode have shown reduction in the intensity, due to the decrease of salt concentration. The splitting of vibrational modes has been analyzed in terms of free ions, ion pairs and aggregates. The bands of SO(3) symmetric stretching mode appearing at 1032 and 1038 cm(-1) in the chosen polymer electrolyte material have been assigned to free ions and ion pairs respectively.

  6. Vibrational, NMR and UV-visible spectroscopic investigation and NLO studies on benzaldehyde thiosemicarbazone using computational calculations

    Science.gov (United States)

    Moorthy, N.; Prabakar, P. C. Jobe; Ramalingam, S.; Pandian, G. V.; Anbusrinivasan, P.

    2016-04-01

    In order to investigate the vibrational, electronic and NLO characteristics of the compound; benzaldehyde thiosemicarbazone (BTSC), the XRD, FT-IR, FT-Raman, NMR and UV-visible spectra were recorded and were analysed with the calculated spectra by using HF and B3LYP methods with 6-311++G(d,p) basis set. The XRD results revealed that the stabilized molecular systems were confined in orthorhombic unit cell system. The cause for the change of chemical and physical properties behind the compound has been discussed makes use of Mulliken charge levels and NBO in detail. The shift of molecular vibrational pattern by the fusing of ligand; thiosemicarbazone group with benzaldehyde has been keenly observed. The occurrence of in phase and out of phase molecular interaction over the frontier molecular orbitals was determined to evaluate the degeneracy of the electronic energy levels. The thermodynamical studies of the temperature region 100-1000 K to detect the thermal stabilization of the crystal phase of the compound were investigated. The NLO properties were evaluated by the determination of the polarizability and hyperpolarizability of the compound in crystal phase. The physical stabilization of the geometry of the compound has been explained by geometry deformation analysis.

  7. Structural, NMR Spectroscopic, and Computational Investigation of Hemin Loading in the Hemophore HasAp from Pseudomonas aeruginosa

    Energy Technology Data Exchange (ETDEWEB)

    Jepkorir, Grace; Rodrguez, Juan Carlos; Rui, Huan; Im, Wonpil; Lovell, Scott; Battaile, Kevin P.; Alontaga, Aileen Y.; Yukl, Erik T.; Monne-Loccoz, Pierre; Rivera, Mario (Oregon State U.); (Kansas); (Hauptman)

    2010-08-16

    When challenged by low-iron conditions several Gram-negative pathogens secrete a hemophore (HasA) to scavenge hemin from its host and deliver it to a receptor (HasR) on their outer membrane for internalization. Here we report results from studies aimed at probing the structural and dynamic processes at play in the loading of the apo-hemophore secreted by P. aeruginosa (apo-HasAp) with hemin. The structure of apo-HasAp shows a large conformational change in the loop harboring axial ligand His32 relative to the structure of holo-HasAp, whereas the loop bearing the other axial ligand, Tyr75, remains intact. To investigate the role played by the axial ligand-bearing loops in the process of hemin capture we investigated the H32A mutant, which was found to exist as a monomer in its apo-form and as a mixture of monomers and dimers in its holo-form. We obtained an X-ray structure of dimeric H32A holo-HasAp, which revealed that the two subunits are linked by cofacial interactions of two hemin molecules and that the conformation of the Ala32 loop in the dimer is identical to that exhibited by the His32 loop in wild type apo-HasAp. Additional data suggest that the conformation of the Ala32 loop in the dimer is mainly a consequence of dimerization. Hence, to investigate the effect of hemin loading on the topology of the His32 loop we also obtained the crystal structure of monomeric H32A holo-HasAp coordinated by imidazole (H32A-imidazole) and investigated the monomeric H32A HasAp and H32A-imidazole species in solution by NMR spectroscopy. The structure of H32A-imidazole revealed that the Ala32 loop attains a 'closed' conformation nearly identical to that observed in wild type holo-HasAp, and the NMR investigations indicated that this conformation is maintained in solution. The NMR studies also highlighted conformational heterogeneity at the H32 loop hinges and in other key sections of the structure. Targeted molecular dynamics simulations allowed us to propose a

  8. Investigation of applicability of a mid-infrared spectroscopic method using an attenuated total reflection accessory and a new near-infrared transmission method for determination of faecal fat

    NARCIS (Netherlands)

    Volmer, M; Kingma, AW; Borsboom, PCF; Wolthers, BG; Kema, IP

    2001-01-01

    In many laboratories, the titrimetric method of Van de Kamer is used for the analysis of faecal fat content of patients suspected of steatorrhoea. We investigated the applicability of a mid-infrared (MIR) spectroscopic method, using an attenuated total reflection (ATR) accessory, and a new near-infr

  9. Investigation of applicability of a mid-infrared spectroscopic method using an attenuated total reflection accessory and a new near-infrared transmission method for determination of faecal fat

    NARCIS (Netherlands)

    Volmer, M; Kingma, AW; Borsboom, PCF; Wolthers, BG; Kema, IP

    In many laboratories, the titrimetric method of Van de Kamer is used for the analysis of faecal fat content of patients suspected of steatorrhoea. We investigated the applicability of a mid-infrared (MIR) spectroscopic method, using an attenuated total reflection (ATR) accessory, and a new

  10. CH3NH3PbI3, A Potential Solar Cell Candidate: Structural and Spectroscopic Investigations.

    Science.gov (United States)

    Nandi, Pronoy; Giri, Chandan; Joseph, Boby; Rath, S; Manju, U; Topwal, D

    2016-12-15

    Hybrid organic-inorganic metal halides of the type CH3NH3PbX3 have emerged as potential materials for photovoltaic applications. In this paper we discuss structural, electronic, and optical spectroscopy investigations performed on high quality single crystals of CH3NH3PbI3. Our results conclusively suggest that CH3NH3PbI3 crystallizes in centrosymmetric space group and the methylammonium moiety exhibits disordered packing at room temperature. Extracted values of the exciton binding energy, the electron-phonon coupling constant, and the schematic energy level diagram constructed from the emission broadening, Raman, and photoemission spectroscopy measurements clearly show the potential of this system in photovoltaic applications.

  11. Spectroscopic investigation of the electronic structure of thin atomic layer deposition HfO{sub 2} films

    Energy Technology Data Exchange (ETDEWEB)

    Corrêa, Silma Alberton, E-mail: silma.alberton@ufrgs.br; Brizzi, Simone; Schmeisser, Dieter [Applied Physics and Sensors, Brandenburg University of Technology Cottbus-Senftenberg, Konrad-Wachsmann-Allee 17, 03046 Cottbus (Germany)

    2016-01-15

    The electronic structure of HfO{sub 2} thin films is investigated employing resonant photoelectron spectroscopy (resPES). The detailed analysis of the O1s resonance profile enables the determination of the partial density of states for the valence and the conduction bands as well as the electronic band gap to be 6.2 eV. The position of the charge neutrality level is evaluated. Thereby, it is demonstrated that the resPES data are able to combine information both for the valence as well as for the conduction band states. In addition, evidences for intrinsic in-gap states attributed to polaronic and charge transfer states are given. Electronic charges within the atomic layer deposition-HfO{sub 2} films are identified, pointing out that the amount of charges is essential to determine the accurate position of the surface potentials.

  12. Ultraviolet-Visible (UV-Vis) and Fluorescence Spectroscopic Investigation of the Interactions of Ionic Liquids and Catalase.

    Science.gov (United States)

    Dong, Xing; Fan, Yunchang; Yang, Peng; Kong, Jichuan; Li, Dandan; Miao, Juan; Hua, Shaofeng; Hu, Chaobing

    2016-11-01

    The inhibitory effects of nine ionic liquids (ILs) on the catalase activity were investigated using fluorescence, absorption ultraviolet-visible spectroscopy. The interactions of ILs and catalase on the molecular level were studied. The experimental results indicated that ILs could inhibit the catalase activity and their inhibitory abilities depended on their chemical structures. Fluorescence experiments showed that hydrogen bonding played an important role in the interaction process. The inhibitory abilities of ILs on catalase activity could be simply described by their hydrophobicity and hydrogen bonding abilities. Unexpected less inhibitory effects of trifluoromethanesulfonate (TfO(-)) might be ascribed to its larger size, which makes it difficult to go through the substrate channel of catalase to the active site. © The Author(s) 2016.

  13. Infrared Spectroscopic Investigation of the Acidic CH Bonds in Cationic n-Alkanes: Pentane, Hexane, and Heptane.

    Science.gov (United States)

    Xie, Min; Matsuda, Yoshiyuki; Fujii, Asuka

    2016-08-18

    Radical cations of n-alkanes (pentane, hexane, and heptane) in the gas phase are investigated by infrared predissociation spectroscopy with the argon or nitrogen tagging. All-trans and gauche-involving conformers are identified for these cations by comparisons of observed infrared spectra and vibrational simulations. Intense CH stretch bands are observed in the frequency region lower than the normal alkyl CH stretch frequency. These low frequencies and high intensities of the CH stretch bands are caused by the CH bond weakening and the enhanced positive charge of the hydrogen atoms through the delocalization of the σ electron in the CH bonds. These effects of the delocalization of the σ electron result in the enhanced acidity of the CH bonds. The conformation as well as alkyl chain length dependence of the acidity of the CH bonds is demonstrated by the CH stretch frequency shift trend.

  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. Spectroscopic investigation of Ginkgo biloba terpene trilactones and their interaction with amyloid peptide Aβ(25-35)

    Science.gov (United States)

    He, Jiangtao; Petrovic, Ana G.; Dzyuba, Sergei V.; Berova, Nina; Nakanishi, Koji; Polavarapu, Prasad L.

    2008-04-01

    The beneficial effects of Ginkgo biloba extract in the "treatment" of dementia are attributed to its terpene trilactone (TTL) constituents. The interactions between TTLs and amyloid peptide are believed to be responsible in preventing the aggregation of peptide. These interactions have been investigated using infrared vibrational absorption (VA) and circular dichroism (VCD) spectra. Four TTLs, namely ginkgolide A (GA), ginkgolide B (GB), ginkgolide C (GC) and bilobalide (BB) and amyloid Aβ(25-35) peptide, as a model for the full length peptide, are used in this study. GA-monoether and GA-diether have also been synthesized and investigated to help understand the role of individual carbonyl groups in these interactions. The precipitation and solubility issues encountered with the mixture of ginkgolide + Aβ peptide for VA and VCD studies were overcome using binary ethanol-D 2O solvent mixture. The experimental VA and VCD spectra of GA, GB, GC and BB, GA-monoether and GA-diether have been analyzed using the corresponding spectra predicted with density functional theory. The time-dependent experimental VA and VCD spectra of Aβ(25-35) peptide and the corresponding experimental spectra in the presence of TTLs indicated that the effect of the TTLs in modulating the aggregation of Aβ(25-35) peptide is relatively small. Such small effects might indicate the absence of a specific interaction between the TTLs and Aβ(25-35) peptide as a major force leading to the reduced aggregation of amyloid peptides. It is possible that the therapeutic effect of G. biloba extract does not originate from direct interactions between TTLs and the Aβ(25-35) peptide and is more complex.

  16. Electron paramagnetic resonance spectroscopic investigation of the inhibition of the phosphoroclastic system of Clostridium sporogenes by nitrite.

    Science.gov (United States)

    Payne, M J; Woods, L F; Gibbs, P; Cammack, R

    1990-10-01

    The proposal that nitrite exerts its inhibitory effect on anaerobic bacteria by direct interaction with the iron-sulphur proteins of the phosphoroclastic system was investigated. The effects of nitrate, nitrite with or without ascorbate, and nitric oxide on the growth of Clostridium sporogenes in liquid cultures at pH 7.4, on the rates of hydrogen production, and on the activities of the enzymes pyruvate-ferredoxin oxidoreductase and hydrogenase, and of ferredoxin were investigated. In agreement with previous studies, nitrate was the least effective inhibitor of cell growth, and nitric oxide the most effective. Nitrite reductase activity was very low in C. sporogenes, indicating that the presence of external reducing agents would be necessary for the reduction of nitrite to nitric oxide. Inhibition by nitrite was enhanced by ascorbate; 0.5 mM-nitrite with 10 mM-ascorbate stopped growth completely. In partially-purified preparations 4.1 mM-NaNO2 and equimolar ascorbate caused complete inactivation of hydrogenase activity but only partial (up to 78%) inactivation of pyruvate-ferredoxin oxidoreductase. This agreed with the loss of hydrogen production observed with nitrite in vivo. Inhibition occurred within 5 min, and was irreversible in each case. Electron paramagnetic resonance (EPR) spectroscopy showed that paramagnetic [Fe(NO)2(SR)2] species were formed during growth in the presence of nitrite, and were associated with cells. However, the intensity of these EPR signals did not correlate with the inhibition of cell growth. The [4Fe-4S] clusters in ferredoxin were shown by EPR spectroscopy to be resistant to treatment with 3.6 mM-NaNO2 and 3.6 mM-ascorbate. It is concluded that the effects of nitrite on pre-formed iron-sulphur proteins are not convincing as a basis for the lethal effects on bacterial cells.

  17. Electrical characterization, phase transition and vibrational spectroscopic investigations of a new organic-inorganic material (C7H10NO)SnCl3

    Science.gov (United States)

    Karoui, Sahel; Chouaib, Hassen; Kamoun, Slaheddine

    2017-10-01

    The X-ray powder analysis, thermogravimetric analysis, differential scanning calorimetry analysis, solid CP-MAS 13C NMR characterization, vibrational spectroscopy and complex impedance spectroscopic data have been carried out on (C7H10NO)SnCl3 compound. The results show that this compound exhibits a phase transition at 314 K which was characterized by 1H NMR between 298 and 336 K, differential scanning calorimetry (DSC), X-rays powder diffraction, Raman spectroscopy and dielectric measurements. The temperature dependence of the 1H NMR spectrum for (C7H10NO)SnCl3 could be explained by invoking reorientation of ammonium group of the 2-methoxyanilinium cation. The most important changes are observed for two lines at 3087 cm-1 and 3175 cm-1 (at room temperature) issued from asymmetric and symmetric stretching vibrations of νs(NH3) and νas(NH3) band, respectively. AC and DC conductivities, complex dielectric permittivity ε*(ω) and complex electrical modulus M*(ω) were respectively studied as temperature and frequency functions. Moreover, the temperature dependence of the DC conductivity and relaxation frequency followed the Arrhenius relation. The frequency dependence of the real part of the AC conductivity in both phases follows the Jonscher's universal dynamic law: σTot.(ω,T) = σDC(T) + B(T) ωS(T). The close values of activation energies, obtained from the thermal behavior of the conductivity and the relaxation time confirm that the transport is through ion-hopping mechanism.

  18. Spectroscopic data

    CERN Document Server

    Melzer, J

    1976-01-01

    During the preparation of this compilation, many people contributed; the compilers wish to thank all of them. In particular they appreciate the efforts of V. Gilbertson, the manuscript typist, and those of K. C. Bregand, J. A. Kiley, and W. H. McPherson, who gave editorial assistance. They would like to thank Dr. J. R. Schwartz for his cooperation and encouragement. In addition, they extend their grati­ tude to Dr. L. Wilson of the Air Force Weapons Laboratory, who gave the initial impetus to this project. v Contents I. I ntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . . . 11. Organization ofthe Spectroscopic Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Methods of Production and Experimental Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Band Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2...

  19. Spectroscopic properties and radiation damage investigation of a diamond based Schottky diode for ion-beam therapy microdosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Verona, C.; Marinelli, Marco; Verona-Rinati, G. [INFN - Dipartimento di Ingegneria Industriale, Università di Roma “Tor Vergata,” Roma (Italy); Magrin, G.; Solevi, P.; Mayer, R. [EBG MedAustron Marie Curie-St. 5, 2700 Wiener Neustadt (Austria); Grilj, V.; Jakšić, M. [Ruder Boškovic Institute, Bijenicka cesta 54, P.O. Box 180, 10002 Zagreb (Croatia)

    2015-11-14

    In this work, a detailed analysis of the properties of a novel microdosimeter based on a synthetic single crystal diamond is reported. Focused ion microbeams were used to investigate the device spectropscopic properties as well as the induced radiation damage effects. A diamond based Schottky diode was fabricated by chemical vapor deposition with a very thin detecting region, about 400 nm thick (approximately 1.4 μm water equivalent thickness), corresponding to the typical size in microdosimetric measurements. A 200 × 200 μm{sup 2} square metallic contact was patterned on the diamond surface by standard photolithography to define the sensitive area. Experimental measurements were carried out at the Ruder Boškovic′ Institute microbeam facility using 4 MeV carbon and 5 MeV silicon ions. Ion beam induced charge maps were employed to characterize the microdosimeter response in terms of its charge collection properties. A stable response with no evidence of polarization or memory effects was observed up to the maximum investigated ion beam flux of about 1.7 × 10{sup 9} ions·cm{sup −2}·s{sup −1}. A homogeneity of the response about 6% was found over the sensitive region with a well-defined confinement of the response within the active area. Tests of the radiation damage effect were performed by selectively irradiating small areas of the device with different ion fluences, up to about 10{sup 12} ions/cm{sup 2}. An exponential decrease of the charge collection efficiency was observed with a characteristic decay constant of about 4.8 MGy and 1 MGy for C and Si ions, respectively. The experimental data were analyzed by means of GEANT4 Monte Carlo simulations. A direct correlation between the diamond damaging effect and the Non Ionizing Energy Loss (NIEL) fraction was found. In particular, an exponential decay of the charge collection efficiency with an exponential decay as a function of NIEL is observed, with a characteristic constant of about

  20. Investigation of the binding affinity in vitamin B12-Bovine serum albumin system using various spectroscopic methods

    Science.gov (United States)

    Makarska-Bialokoz, Magdalena

    2017-09-01

    The binding affinity between vitamin B12 (VitB12) and bovine serum albumin (BSA) has been investigated in aqueous solution at pH = 7.4, employing UV-vis absorption and steady-state, synchronous and three-dimensional fluorescence spectra techniques. Representative effects noted for BSA intrinsic fluorescence resulting from the interactions with VitB12 confirm the formation of π-π stacked non-covalent and non-fluorescent complexes in the system VitB12-BSA. All the determined parameters, the binding, fluorescence quenching and bimolecular quenching rate constants (of the order of 104 L mol- 1, 103 L mol- 1 and 1011 L mol- 1 s- 1, respectively), as well as Förster resonance energy transfer parameters validate the mechanism of static quenching. The interaction with VitB12 induces folding of the polypeptide chains around Trp residues of BSA, resulting in a more hydrophobic surrounding. Presented outcomes suggest that the addition of VitB12 can lead to the more organized BSA conformation and its more folded tertiary structure, what could influence the physiological functions of bovine serum albumin, notably in case of its overuse or abnormal metabolism.

  1. Tin(IV) derivatives of 2,6-pyridinedicarboxylate: A 119Sn Mössbauer spectroscopic investigation

    Science.gov (United States)

    Costa, Luiz C. M.; Maia, José Roberto da S.; de Lima, Geraldo M.; Ardisson, José D.

    2006-02-01

    A series of organotin(IV) derivatives of 2,6-pyridinedicarboxylate has been investigated by Mössbauer spectroscopy in order to elucidate aspects concerning bonding and structural features in the solid state. A geometrical pattern of five-fold coordination at the metal centre has been revealed for SnCl 3Bu and SnClBu 3 derivatives. Trans stereochemistry for the butyl and vinyl groups of SnCl 2Bu 2 and SnCl 2(Vin) 2 derivatives has also been identified by this method. The isomer shift for the divinyl derivative is concurrent to a 7-coordinate metal centre contrasting to that for the dibutyl one. Although there is a discrepancy in isomer shift between these compounds, both have seven-fold coordination at the Sn(IV) nucleus. The resulting data has given evidence that 2,6-pyridinedicarboxylate is acting as a tridentate ligand through pyridil and carbolxylate moiety to all derivatives except for SnClBu 3. For the latter, the coordination mode occurs via carboxylate groups. The overall data support distorted geometrical pattern to all complexes in solid state.

  2. Spectroscopic Investigations of the Binding Interaction of a New Indanedione Derivative with Human and Bovine Serum Albumins

    Directory of Open Access Journals (Sweden)

    Mihaela Hillebrand

    2009-04-01

    Full Text Available Binding of a newly synthesized indanedione derivative, 2-(2-hydroxy-3-ethoxybenzylidene-1,3-indanedione (HEBID, to human and bovine serum albumins (HSA and BSA, under simulated physiological conditions was monitored by fluorescence spectroscopy. The binding parameters (binding constants and number of binding sites and quenching constants were determined according to literature models. The quenching mechanism was assigned to a Förster non-radiative energy transfer due to the HEBID-SA complex formation. A slightly increased affinity of HEBID for HSA was found, while the number of binding sites is approximately one for both albumins. The molecular distance between donor (albumin and acceptor (HEBID and the energy transfer efficiency were estimated, in the view of Förster’s theory. The effect of HEBID on the protein conformation was investigated using circular dichroism and synchronous fluorescence spectroscopies. The results revealed partial unfolding in the albumins upon interaction, as well as changes in the local polarity around the tryptophan residues

  3. Systematic investigation of the toxicity interaction of ZnSe@ZnS QDs on BSA by spectroscopic and microcalorimetry techniques.

    Science.gov (United States)

    Ding, Ling; Zhou, Peijiang; Zhan, Hongju; Zhao, Xiaohu; Chen, Chi; He, Zhenyu

    2013-08-01

    The interaction of ZnSe@ZnS quantum dots (QDs) and bovine serum albumin (BSA) was investigated by means of fluorescence (FL) spectrometry, circular dichroism (CD) spectra, and isothermal titration calorimetry (ITC). The fluorescence intensity of BSA decreased regularly with the increasing of QDs concentration. The decrease of BSA fluorescence intensity was proved to be a kind of static quenching. CD results show the helicity of BSA decreased from 38.04% to 26.51% with the addition of QDs, which suggests a stronger structural change that is related to a low degree of surface coverage. And also, both ion strength and pH value could affect the interaction between BSA and QDs, suggesting that both the static electronic attraction and H-bond contribute to the interaction between BSA and QDs. The thermodynamics of interaction between BSA and QDs were calculated from ITC data. Both enthalpy and entropy changes were favorable for the interaction in Tris-buffer, while only enthalpy change was favorable for the interaction in NaCl or HCl solution.

  4. Spectroscopic investigation on sonodynamic and sonocatalytic damage of BSA molecules by Thymol Blue (TB) derivants under ultrasonic irradiation.

    Science.gov (United States)

    Wang, Qi; Wu, Qiong; Wang, Jun; Chen, Dandan; Li, Ying; Gao, Jingqun; Wang, Baoxin

    2014-07-15

    In this paper, the Thymol Blue derivants including Thymol Blue (thymolsulfonphthalein), Thymol Blue-DA (3,3'-Bis [N,N-bis (carboxymethyl) aminomethyl] thymolsulfonphthalein) and Thymol Blue-DA-Fe(III) (3,3'-Bis [N,N-bis (carboxymethyl) aminomethyl] thymolsulfonphthalein-Ferrous(III)) were adopted as sonosensitizers to study the sonodynamic and sonocatalytic activities under ultrasonic irradiation. At first, the interaction of Thymol Blue derivants with bovine serum albumin (BSA) was studied by fluorescence spectroscopy. On that basis, the sonodynamic and sonocatalytic damages of Thymol Blue derivants to BSA under ultrasonic irradiation were investigated by the combination of UV-vis, circular dichroism (CD) and fluorescence spectroscopy. Meanwhile, some influenced factors (ultrasonic irradiation time, Thymol Blue derivants concentration and ionic strength) on the damaging degree of BSA molecules were also reviewed. In addition, synchronous fluorescence spectra were used to estimate the binding and damage sites of Thymol Blue derivants to BSA. Finally, the generation of ROS during sonodynamic and sonocatalytic processes was confirmed by the method of Oxidation-Extraction Spectrometry (OEP). Perhaps, this paper may offer some important subjects for the study of Thymol Blue derivants in sonodynamic therapy (SDT) and sonocatalytic therapy (SCT) technologies for tumor treatment and the effect of the amino acid and central metal.

  5. Spectroscopic Investigation of the Canopy Configurations in Nanoparticle Organic Hybrid Materials of Various Grafting Densities during CO 2 Capture

    KAUST Repository

    Petit, Camille

    2012-01-12

    Novel liquid-like nanoparticle organic hybrid materials (NOHMs) made of polyetheramine chains tethered onto functionalized silica nanoparticles were synthesized and characterized before and after exposure to CO 2 using NMR, Raman, and ATR FT-IR spectroscopies in order to investigate the effect of the grafting densities on the NOHM canopy structure. Considering the promising tunable properties for CO 2 capture of NOHMs, this study was conducted to provide important structural information to better design NOHMs for CO 2 capture. In order to minimize the CO 2 absorption via enthalpic effect and provide a more accurate assessment of the structural effects, the NOHMs were synthesized without task-specific groups. A greater chain ordering and decreased intermolecular interactions were observed in NOHMs compared to the unbound polymer. This was attributed to the specific structural arrangement of the frustrated canopy. The distinct configuration of grafted polymer chains caused different CO 2 packing and CO 2-induced swelling behaviors between the NOHMs and the unbound polymer. The grafting density influenced the ordering and coupling of the polymer chains and CO 2-induced swelling. Its effect on the CO 2 packing behavior was less pronounced. © 2011 American Chemical Society.

  6. Synthesis, crystal growth and spectroscopic investigation of novel metal organic crystal: β-Alanine cadmium bromide monohydrate (β-ACBM)

    Science.gov (United States)

    Renugadevi, R.; Kesavasamy, R.

    2014-07-01

    β-Alanine cadmium bromide monohydrate (β-ACBM), a new metal organic crystal has been grown from aqueous solution by slow evaporation technique. The grown crystals have been subjected to single crystal X-ray diffraction analysis to determine the crystal structure. The β-ACBM crystallized in monoclinic system with space group P21/c. The presence of protons and carbons in the β-alanine cadmium bromide monohydrate was confirmed by 1H and 13C nuclear magnetic resonance spectral analysis. The mode of vibration of different molecular groups present in β-ACBM was identified by FT-IR spectral analysis. Transparency of crystals in UV-Vis-NIR region has also been studied. The thermal characteristics of as-grown crystals were analyzed using thermo gravimetric and differential thermal analyses. The magnetic property of the grown crystal was investigated using Vibrating Sample Magnetometer (VSM) at ambient temperature. The mechanical stability of β-ACBM was evaluated by Vickers microhardness measurement.

  7. Investigation of the Interaction between Patulin and Human Serum Albumin by a Spectroscopic Method, Atomic Force Microscopy, and Molecular Modeling

    Directory of Open Access Journals (Sweden)

    Li Yuqin

    2014-01-01

    Full Text Available The interaction of patulin with human serum albumin (HSA was studied in vitro under normal physiological conditions. The study was performed using fluorescence, ultraviolet-visible spectroscopy (UV-Vis, circular dichroism (CD, atomic force microscopy (AFM, and molecular modeling techniques. The quenching mechanism was investigated using the association constants, the number of binding sites, and basic thermodynamic parameters. A dynamic quenching mechanism occurred between HSA and patulin, and the binding constants (K were 2.60 × 104, 4.59 × 104, and 7.01 × 104 M−1 at 288, 300, and 310 K, respectively. Based on fluorescence resonance energy transfer, the distance between the HSA and patulin was determined to be 2.847 nm. The ΔG0, ΔH0, and ΔS0 values across various temperatures indicated that hydrophobic interaction was the predominant binding force. The UV-Vis and CD results confirmed that the secondary structure of HSA was altered in the presence of patulin. The AFM results revealed that the individual HSA molecule dimensions were larger after interaction with patulin. In addition, molecular modeling showed that the patulin-HSA complex was stabilized by hydrophobic and hydrogen bond forces. The study results suggested that a weak intermolecular interaction occurred between patulin and HSA. Overall, the results are potentially useful for elucidating the toxigenicity of patulin when it is combined with the biomolecular function effect, transmembrane transport, toxicological, testing and other experiments.

  8. Synthesis, vibrational spectroscopic investigations, molecular docking, antibacterial and antimicrobial studies of 5-ethylsulphonyl-2-(p-aminophenyl)benzoxazole

    Science.gov (United States)

    Parveen S, Shana; Al-Alshaikh, Monirah A.; Panicker, C. Yohannan; El-Emam, Ali A.; Arisoy, Mustafa; Temiz-Arpaci, Ozlem; Van Alsenoy, C.

    2016-07-01

    The optimized molecular structure, vibrational wavenumbers, corresponding vibrational assignments of 5-ethylsulphonyl-2-(p-aminophenyl)benzoxazole have been investigated experimentally and theoretically based on density functional theory. Synthesis and antibacterial and antimicrobial activities of the title compound were reported. The FT-IR and FT-Raman spectra were recorded in solid phase and the experimental bands were assigned and characterized on the basis of potential energy distribution. The HOMO and LUMO energies show that the charge transfer occur within the molecule. Stability arising from hyperconjugative interactions and charge delocalization were analysed using natural bond orbital analysis. Binding free energy of -9.8 kcal/mol as predicted by docking studies suggests good binding affinity and the inhibitor forms a stable complex with FAK as is evident from the ligand-receptor interactions. The title compound possesses lower activity against Candida albicans with MIC value of 64 μg/ml than the compared reference drugs as fluconazole and amphotericin B and possesses the same activity with value of 64 μg/ml against Candida krusei as the reference drug, fluconazole.

  9. Micro-structural, electrical and spectroscopic investigations of pulsed laser ablated palladium incorporated nanostructured tungsten oxide films.

    Science.gov (United States)

    Lethy, K J; Beena, D; Pillai, V P Mahadevan; Suresh, K A

    2009-09-01

    Pure and Pd incorporated (0.5, 1 and 5 wt%) WO3 films are prepared on quartz substrates using pulsed laser ablation (PLD) technique in an oxygen ambient of 0.12 mbar, at a substrate temperature (Ts) of 873 K. Palladium incorporation effects on the microstructure, optical and electrical properties of tungsten oxide films are systematically investigated using techniques like X-ray diffraction (XRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), micro-Raman spectroscopy, UV-Vis absorption spectroscopy and temperature dependent electrical resistivity measurements. The micro-structural analysis by XRD and micro-Raman indicates that Pd addition can perturb the tungsten oxide lattice and suppress the grain growth. Optical band gap values of the films increases from 3.17 eV for pure WO3 to 3.29 eV for 5 wt% Pd incorporated WO3 films. All the films present high transparency in the visible spectral range. The electrical resistivity studies of the pure and Pd incorporated films done at room temperature and for the range of temperature; 170-450 K reveal that Pd addition can lower the resistivity of the WO3 thin films. Room temperature resistivity as well as activation energy of the film decreases exponentially with Pd incorporation concentration. Highly transparent, nanocrystalline and semiconducting WO3 films with low resistivity obtained by Pd incorporation can make WO3 suitable for microelectronics industry and for gas sensing applications.

  10. Spectroscopic investigation, HOMO-LUMO and NLO studies on L-histidinium maleate based on DFT approach

    Science.gov (United States)

    Dhanavel, S.; Stephen, A.; Asirvatham, P. Samuel

    2017-05-01

    The molecular structure of the title compound L-Histidinium Maleate (LHM) was constructed and optimized based on Density Functional Theory method (DFT-B3LYP) with the 6-31G (d,p) basis set. The fundamental vibrational spectral assignment was analyzed with the aid of optimized structure of LHM. The study on electronic properties such as, HOMO-LUMO energies and absorption wavelength were performed using Time dependent DFT (TD-DFT) approach which reveals that energy transfer occur within the molecule. 13C NMR chemical shift values were measured using Gauge independent atomic orbital method (GIAO) and the obtained values are in good agreement with the reported experimental values. Hardness, ionization potential and electrophilicity index also calculated. The electric dipole moment (μtot) and hyperpolarizability (βtot) values of the investigated molecules were computed. The calculated value (β) was 3.7 times higher than that of urea, which confirms the LHM molecule is a potential candidate for NLO applications.

  11. Characterisation of agricultural waste-derived biochars and their sorption potential for sulfamethoxazole in pasture soil: A spectroscopic investigation

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, Prakash; Sarmah, Ajit K., E-mail: a.sarmah@auckland.ac.nz

    2015-01-01

    We investigated the effects of feedstock type and pyrolysis temperatures on the sorptive potential of a model pastoral soil amended with biochars for sulfamethoxazole (SMO), using laboratory batch sorption studies. The results indicated that high temperature chars exhibited enhanced adsorptive potential, compared to low temperature chars. Pine sawdust (PSD) biochar produced at 700 °C using the steam gasification process exhibited the highest sorptive capacity (2-fold greater than the control treatment) for SMO among the three biochars used. Soils amended with green waste (GW) biochars produced at three different pyrolysis temperatures showed a small increase in SMO sorption with the increases in temperature. The NMR spectra, the elemental molar ratios (H/C, O/C) and polarity index (O + N)/C of the biochars revealed that PSD biochar possessed the highest degree of aromatic condensation compared to CC and GW chars. These results correlated well with the sorption affinity of each biochar, with effective distribution coefficient (K{sub d}{sup eff}) being highest for PSD and lowest for GW biochars. X-ray photoelectron spectroscopy results for the biochars showed a relatively large difference in oxygen containing surface functional groups amongst the GW biochars. However, they exhibited nearly identical sorption affinity to SMO, indicating negligible role of oxygen containing surface functional groups on SMO sorption. These observations provide important information on the use of biochars as engineered sorbents for environmental applications, such as reducing the bioavailability of antibiotics and/or predicting the fate of sulfonamides in biochar-amended soils. - Highlights: • High temperature chars showed enhanced adsorptive potential, compared to low temperature chars. • Oxygen containing acidic functional groups of biochar play negligible role in sorption. • Biochar properties like specific surface area and aromaticity enhanced its sorption capacity.

  12. Spectroscopic Characterization, Computational Investigation, and Comparisons of ECX− (E = As, P, and N; X = S and O) Anions

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Gao-Lei; Chen, Bo; Transue, Wesley J.; Yang, Zheng; Grutzmacher, Hansjorg; Driess, Matthias; Cummins, Christopher C.; Borden, Weston; Wang, Xue-Bin

    2017-07-05

    Three newly-synthesized [Na+(221-kryptofix)] salts containing AsCO–, PCO–, and PCS– anions were successfully electrosprayed into the vacuum, and the ECX– (E = As, P; X = O, S) anions were investigated by negative ion photoelectron spectroscopy (NIPES) and high resolution photoelectron imaging spectroscopy. For each ECX– anion, a well-resolved NIPE spectrum was obtained, in which every major peak is split into a doublet. The splittings are attributed to spin-orbit coupling (SOC) in the ECX• radicals. Vibrational progressions in the NIPE spectra of ECX– were assigned to the symmetric and antisymmetric stretching modes in ECX• radicals. The electron affinities (EAs) and SOC splittings of ECX• are determined from the NIPE spectra to be: AsCO•: EA = 2.414 ± 0.002 eV, SOC splitting = 988 cm-1; PCO•: EA = 2.670 ± 0.005 eV, SOC splitting = 175 cm-1; PCS•: EA = 2.850 ± 0.005 eV, SOC splitting = 300 cm-1. Calculations using the B3LYP, CASPT2, and CCSD(T) methods all predict linear geometries for both the anions and neutral radicals. The calculated EAs and SOC splittings for ECX• are in excellent agreement with the experimentally-measured values. The simulated NIPE spectra, based on the calculated Franck-Condon factors, and SOC splittings nicely reproduce all of the observed spectral peaks, thus allowing unambiguous spectral assignments. The finding that PCS has the greatest EA of the three triatomic molecules considered here is counterintuitive based upon electronegativity considerations, but understandable in terms of the HOMO of PCS– having the greatest degree of delocalization onto both terminal atoms.

  13. Spectroscopic (infrared, Raman, UV and NMR) analysis, Gaussian hybrid computational investigation (MEP maps/HOMO and LUMO) on cyclohexanone oxime

    Science.gov (United States)

    Ramalingam, S.; Karabacak, M.; Periandy, S.; Puviarasan, N.; Tanuja, D.

    2012-10-01

    In the present analysis, FT-IR/FT-Raman spectra of the cyclohexanone oxime (CHO, C6H11NO) are recorded. The observed vibrational frequencies are assigned and the computational calculations are carried out by HF and DFT (B3LYP and B3PW91) methods with 6-311++G(d,p) basis set and the corresponding results are tabulated. In order to yield good coherence with observed values, the calculated frequencies are scaled by appropriate scale factors. The complete assignments are performed on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. The alternation of structure of cyclohexanone due to the substitution of NOH is investigated. The vibrational sequence pattern of the molecule related to the substitutions is analyzed. Comparison of the observed fundamental vibrational frequencies of CHO and calculated results by density functional (B3LYP and B3PW91) and HF methods indicates that B3LYP is superior to the scaled HF and B3PW91 approach for molecular vibrational problems. Moreover, 13C NMR and 1H NMR chemical shifts are calculated by using the gauge independent atomic orbital (GIAO) method with HF/B3LYP/B3PW91 methods and the same basis set. A study on the electronic properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, are performed by HF and DFT methods. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. NLO properties and Mulliken charges of the CHO was also calculated and interpreted. The thermodynamic properties (heat capacity, entropy, and enthalpy) of the title compound at different temperatures are calculated in gas phase.

  14. Infrared and Fluorescence Spectroscopic Investigations of the Acyl Surface Modification of Hydrogel Beads for the Deposition of a Phospholipid Coating.

    Science.gov (United States)

    Grossutti, Michael; Seenath, Ryan; Lipkowski, Jacek

    2015-10-27

    The scaffolded vesicle has been employed as an alternative means of developing natural model membranes and envisioned as a potential nutraceutical transporter. Furthering the research of the scaffolded vesicle system, a nucleophilic substitution reaction was implemented to form an ester linkage between palmitate and terminal hydroxyl groups of dextran in order to hydrophobically modify the hydrogel scaffold. An average tilt angle of 38° of the hydrophobic palmitate modifying layer on the surface of the hydrogel was determined from dichroic ratios obtained from infrared spectra collected in the attenuated total reflection (ATR) configuration. ATR-IR studies of the DMPC-coated acylated hydrogel demonstrated that the hydrocarbon chains of the DMPC coating was similar to those of the DMPC bilayers and that the underlying palmitate layer had a negligible effect on the average tilt angle (26°) of the DMPC coating. The permeability of this acylated hydrogel was investigated with fluorescence spectroscopy and the terbium/dipicolinic acid assay. The hydrophobic modification on the surface of the hydrogel bead allowed for an efficient deposition of a DMPC layer that served as an impermeable barrier to terbium efflux. About 72% of DMPC-coated acylated hydrogel beads showed ideal barrier properties. The remaining 28% were leaking, but the half-life of terbium efflux of the DMPC-coated acylated hydrogel was increasing, and the total amount of leaked terbium was decreasing with the incubation time. The half-life time and the retention were considered a marked improvement relative to past scaffolded vesicle preparations. The process of acylating hydrogel beads for efficient DMPC deposition has been identified as another viable method for controlling the permeability of the scaffolded vesicle.

  15. Internal structural changes in keratin fibres resulting from combined hair waving and stress relaxation treatments: a Raman spectroscopic investigation.

    Science.gov (United States)

    Kuzuhara, A

    2016-04-01

    The objective of our research was to investigate the influence of chemical treatments (reduction, stress relaxation and oxidation) on hair keratin fibres. The structure of cross-sections at various depths of virgin white human hair resulting from permanent waving treatments with stress relaxation process was directly analysed at a molecular level using Raman spectroscopy. In particular, the three disulphide (-SS-) conformations in human hair were compared by S-S band analysis. The gauche-gauche-gauche (GGG) and gauche-gauche-trans (GGT) contents of -SS- groups remarkably decreased, while the trans-gauche-trans (TGT) content was not changed by performing the reduction process with thioglycolic acid. In addition, the high-temperature stress relaxation process after reduction accelerated the disconnection of -SS- (GGG and GGT) groups in the human hair, while the low-temperature stress relaxation process after reduction accelerated the reconnection of -SS- (GGG and GGT) groups. Moreover, the S-O band intensity at 1042 cm(-1) , assigned to cysteic acid, existing in the cuticle region and the surface of the cortex region increased, while the GGG content significantly decreased by performing the oxidation process after the reduction and the high-temperature stress relaxation processes. The author concluded that the high-temperature relaxation process after reduction accelerated the disconnection of -SS- (GGG and GGT) groups, thereby leading to the remarkable local molecular disorganization (an increase in the cysteic acid content and a decrease in the GGG content) on the cuticle and cortex cells during the oxidation process. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  16. Line-of-duty deaths among U.S. firefighters: an analysis of fatality investigations.

    Science.gov (United States)

    Kunadharaju, Kumar; Smith, Todd D; DeJoy, David M

    2011-05-01

    More than 100 firefighters die in the line-of-duty in the U.S. each year and over 80,000 are injured. This study examined all firefighter fatality investigations (N = 189) completed by the National Institute for Occupational Safety and Health (NIOSH) for fatalities occurring between 2004 and 2009. These investigations produced a total of 1167 recommendations for corrective actions. Thirty-five high frequency recommendations were derived from the total set: six related to medical fatalities and 29 to injury-related fatalities. These high frequency recommendations were mapped onto the major operational components of firefighting using a fishbone or cause-effect diagram. Over 70% of the 30 non-external recommendations were categorized within the personnel and incident command components of the fishbone diagram. Root cause techniques suggested four higher order causes: under-resourcing, inadequate preparation for/anticipation of adverse events during operations, incomplete adoption of incident command procedures, and sub-optimal personnel readiness. These findings are discussed with respect to the core culture of firefighting.

  17. Effect of an allophanic soil on humification reactions between catechol and glycine: Spectroscopic investigations of reaction products

    Science.gov (United States)

    Fukushima, Masami; Miura, Akitaka; Sasaki, Masahide; Izumo, Kenji

    2009-01-01

    Adduction of amino acids to phenols is a possible humification reaction pathway [F.J. Stevenson, Humus Chemistry: Genesis, Composition, Reaction, second ed., Wiley, New York, 1994, pp. 188-211; M.C. Wang, P.M. Huang, Sci. Total Environ. 62 (1987) 435; M.C. Wang, P.M. Huang, Soil Sci. Soc. Am. J. 55 (1991) 1156; M.C. Wang, P.M. Huang, Geoderma 112 (2003) 31; M.C. Wang, P.M. Huang, Geoderma 124 (2005) 415]. To elucidate the reaction kinetics and products of abiotic humification, the effects of an allophanic soil on the adduction of amino acids to phenols were investigated using catechol (CT) and glycine (Gly) as a model phenol and amino acid, respectively. An aqueous solution containing CT and Gly (pH 7.0) in the presence of allophanic soil was incubated for 2 weeks, and the kinetics of the humification reactions were monitored by analysis of absorptivity at 600 nm ( E600). A mixture of CT and Gly in the absence of allophanic soil was used as a control. The E600 value increased markedly in the presence of allophanic soil. In addition, unreacted CT was detected in the control reaction mixture, but not in the allophane-containing reaction mixture. Under the sterilized conditions, absorbance at 600 nm for the control reaction mixture was significantly smaller than that for the allophanic soil-containing reaction mixture, which indicates there was no microbial participation during incubation. These results indicate that the allophanic soil effectively facilitated humification reactions between CT and Gly. The reaction mixtures were acidified and humic-like acid (HLA) was isolated as a precipitate. The elemental composition, acidic functional group contents, molecular weight, FT-IR, solid-state CP-MAS 13C NMR, and 1H NMR spectra of the purified HLAs were analyzed. The results of these analyses indicate that the nitrogen atom of Gly binds to the aromatic carbon of CT in the HLA products.

  18. Raman Spectroscopic Online Investigation of Respiratory Quotients in Pinus Sylvestris and Picea Abies during Drought and Shading

    Science.gov (United States)

    Hanf, S.; Fischer, S.; Hartmann, H.; Trumbore, S.; Popp, J.; Frosch, T.

    2014-12-01

    Drought and heat waves have been linked to forest mortality event across the globe. The underlying physiological processes are still not elucidated but both tree carbon and water relations have been identified as the driving forces. While studies on tree hydraulics are straightforward, studies on the tree carbon balance are not. For example, the use of different carbon compounds for maintenance respiration during drought cannot be assessed with measurements of carbon pools but requires real-time analyses of respiration stoichiometry. However, so far there were no technical solutions for such applications. Here we introduce cavity-enhanced Raman spectrometry (CERS) for simultaneous real-time monitoring of O2 and CO2 and rapid and continuous quantification of dark respiration rates and the respiratory quotient (RQ), i.e. the ratio of CO2 produced over O2 consumed during respiration. This ratio indicates the proportions of different substrates (carbohydrates [COH], lipids, proteins) used during respiration and allows fundamental insights into tree physiology. CERS combines high temporal resolution with a high dynamic concentration range for all important gases, ranging from few ppm to 100 vol. % with a single measurement every few seconds. The respiration analysis of tree branches was performed in a closed chamber for two species of different drought tolerance, Pinus sylvestris and Picea abies. We applied not only drought but also a shading treatment because both cause reductions in carbon assimilation rates but have different effects on tree hydraulics. Declines in RQ during shading in both species indicate a switch from pure COH metabolism to a mixture of COH, lipids and proteins. During drought such declines occurred only in the drought-tolerant pine but not in spruce and the underlying more dynamic carbon use strategy in pine may provide a physiological basis for its drought tolerance, more detailed investigation still pending. Our study highlights the suitability

  19. Investigation on synthesis, structure, morphology, spectroscopic and electrochemical studies of praseodymium-doped ceria nanoparticles by combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Esther Jeyanthi, C., E-mail: esther.jeyanthi@yahoo.com [Research and Development Centre, Bharathiar University, Coimbatore 641046 (India); Department of Physics, Panimalar Engineering College, Chennai 600123, TN (India); Siddheswaran, R. [New Technologies Research Centre, University of West Bohemia in Pilsen, Plzeň 30614 (Czech Republic); Kumar, Pushpendra [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Karl Chinnu, M. [Department of Applied Physics, Tunghai University, Taichung City, 40740, Taiwan (China); Rajarajan, K. [Department of Physics, Rajeswari Vedachalam Govt. Arts College, Chengalpet 603001, TN (India); Jayavel, R. [Centre for Nanoscience and Technology, Anna University, Chennai 600025 (India)

    2015-02-01

    The investigation deals with the synthesis and characterization of praseodymium doped ceria (PDC) nanoparticles by citrate nitrate auto-combustion method. The as prepared PDC powders were calcined at 700 °C, and then dense cylindrical electrolyte bodies were fabricated by uni-axial compression followed by sintering at 1200 °C. The PDC nanocrystals and compacts were subjected to characterization studies such as X-ray diffraction, scanning and transmission electron microscopy, elemental analysis, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and electrochemical analyses. The crystal structure of PDC was found to be a cubic fluorite system by X-ray diffraction analysis (XRD). The surface morphologies and the grain distributions of the calcined nanoparticles and sintered bodies were studied by scanning electron microscopy (SEM). The grain size of the sintered material was found to be in the range from 100 nm to 500 nm. Transmission electron microscopic (TEM) images revealed the presence of polyhedral, sphere-like shape of the nanoparticles with a size range 10–25 nm. The symmetric stretching mode of the Ce–O was obtained at 555 cm{sup −1} in the FTIR spectrum. The Raman active mode for the PDC was obtained at 457 cm{sup −1}. The presence of oxygen vacancies was confirmed from the weaker absorption band observed at 560 cm{sup −1} in the Raman spectrum. The change in current density with increasing sweep scan potential was studied by cyclic voltammetry (CV) analysis. The specific capacitance range of the PDC was calculated as 20–72.4 Fg{sup −1}. - Highlights: • Praseodymium doped Ceria was synthesized by citrate nitrate auto-combustion method. • XRD revealed that they crystallize as single-phase cubic fluorite structure. • FTIR and RAMAN studies were carried to analyze the existence of functional groups. • The morphology of the particles and compacts were analyzed by SEM and TEM. • Cyclic voltammetry (CV) for the

  20. Near-infrared spectroscopic investigation of water in supercritical CO2 and the effect of CaCl2

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zheming; Felmy, Andrew R.; Thompson, Christopher J.; Loring, John S.; Joly, Alan G.; Rosso, Kevin M.; Schaef, Herbert T.; Dixon, David A.

    2013-01-01

    Near-infrared (NIR) spectroscopy was applied to investigate the dissolution and chemical interaction of water dissolved into supercritical carbon dioxide (scCO2) and the influence of CaCl2 in the co-existing aqueous phase at fo empe e : 40 50 75 nd 100 C at 90 atm. Consistent with the trend of the vapor pressure of water, the solubility of pure water in scCO2 inc e ed f om 40 °C (0.32 mole%) o 100 °C (1.61 mole%). The presence of CaCl2 negatively affects the solubility of water in scCO2: at a given temperature and pressure the solubility of water decreased as the concentration of CaCl2 in the aqueous phase increased, following the trend of the activity of water. A 40 °C, the water concentration in scCO2 in contact with saturated CaCl2 aqueous solution was only 0.16 mole%, a drop of more than 50% as compared to pure water while that a 100 °C was 1.12 mole%, a drop of over 30% as compared to pure water, under otherwise the same conditions. Analysis of the spectral profiles suggested that water dissolved into scCO2 exists in the monomeric form under the evaluated temperature and pressure conditions, for both neat water and CaCl2 solutions. However, its rotational degrees of freedom decrease at lower temperatures due to higher fluid densities, leading to formation of weak H2O:CO2 Lewis acid-base complexes. Similarly, the nearly invariant spectral profiles of dissolved water in the presence and absence of saturated CaCl2 under the same experimental conditions was taken as evidence that CaCl2 dissolution in scCO2 was limited as the dissolved Ca2+/CaCl2 would likely be highly hydrated and would alter the overall spectra of waters in the scCO2 phase.

  1. Spectroscopic investigations of plasma nitriding processes: A comparative study using steel and carbon as active screen materials

    Science.gov (United States)

    Hamann, S.; Burlacov, I.; Spies, H.-J.; Biermann, H.; Röpcke, J.

    2017-04-01

    Low-pressure pulsed DC H2-N2 plasmas were investigated in the laboratory active screen plasma nitriding monitoring reactor, PLANIMOR, to compare the usage of two different active screen electrodes: (i) a steel screen with the additional usage of CH4 as carbon containing precursor in the feeding gas and (ii) a carbon screen without the usage of any additional gaseous carbon precursor. Applying the quantum cascade laser absorption spectroscopy, the evolution of the concentration of four stable molecular species, NH3, HCN, CH4, and C2H2, has been monitored. The concentrations were found to be in a range of 1012-1016 molecules cm-3. By analyzing the development of the molecular concentrations at variations of the screen plasma power, a similar behavior of the monitored reaction products has been found for both screen materials, with NH3 and HCN as the main reaction products. When using the carbon screen, the concentration of HCN and C2H2 was 30 and 70 times higher, respectively, compared to the usage of the steel screen with an admixture of 1% CH4. Considering the concentration of the three detected hydrocarbon reaction products, a combustion rate of the carbon screen of up to 69 mg h-1 has been found. The applied optical emission spectroscopy enabled the determination of the rotational temperature of the N2+ ion which has been in a range of 650-900 K increasing with the power in a similar way in the plasma of both screens. Also with power the ionic component of nitrogen molecules, represented by the N2+ (0-0) band of the first negative system, as well as the CN (0-0) band of the violet system increase strongly in relation to the intensity of the neutral nitrogen component, i.e., the N2 (0-0) band of the second positive system. In addition, steel samples have been treated with both the steel and the carbon screen resulting in a formation of a compound layer of up to 10 wt. % nitrogen and 10 wt. % carbon, respectively, depending on the screen material.

  2. Synthesis, crystal structure, spectroscopic investigations and DFT calculations of the copper(II) complex of 4-(Trifluoromethyl)pyridine-2-carboxylic acid

    Science.gov (United States)

    Vural, Hatice; Orbay, Metin

    2017-10-01

    A novel polymeric complex of Cu(II) ion, [Cu(tfpc)2]n [tfpc: 4-(Trifluoromethyl)pyridine-2-carboxylate] has been prepared and characterized spectroscopically (by FT-IR) and structurally (by single-crystal XRD). The geometry around the Cu(II) center can be described as square planar made by tfpc ligand having nitrogen and oxygen atoms. Additionally, the Cu(II) complex has a one-dimensional double-bridged polymeric structure in which Cu(II) ions are bridged by two oxygen atoms of adjacent planes. The crystal packing has been stabilized by Csbnd H⋯O intra and intermolecular hydrogen bonds. The molecular structure of the Cu(II) complex has been optimized using the Density Functional Theory (DFT) B3LYP, B3PW91 and PBEPBE levels with 6-311+G(d,p) basis set. The calculated electronic spectra have been explained using the time dependent DFT (TD-DFT) method by applying the polarized continuum model (PCM). The vibrational spectral data have been calculated and compared with experimental ones. The non-linear optical (NLO) properties of the title compound have been investigated using the DFT method with three different levels. Natural Bond Orbital (NBO) property of the Cu(II) complex has been performed by the B3LYP density functional and the 6-311+G(d,p) basis set.

  3. The spectroscopic properties of anticancer drug Apigenin investigated by using DFT calculations, FT-IR, FT-Raman and NMR analysis

    Science.gov (United States)

    Mariappan, G.; Sundaraganesan, N.; Manoharan, S.

    2012-09-01

    The FT-Raman and FT-Infrared spectra of solid Apigenin sample were measured in order to elucidate the spectroscopic properties of title molecule in the spectral range of 3500-50 cm-1 and 4000-400 cm-1, respectively. The recorded FT-IR and FT-Raman spectral measurements favor the calculated (by B3LYP/6-31G(d,p) method) structural parameters which are further supported by spectral simulation. Additional support is given by the collected 1H and 13C NMR spectra recorded with the sample dissolved in DMSO. The predicted chemical shifts at the B3LYP/6-31G(d) level obtained using the Gauge-Invariant Atomic Orbitals (GIAO) method with and without inclusion of solvent using the Polarizable Continuum Model (PCM). By using TD-DFT method, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and the experimental one is determined. The UV-visible absorption spectra of the compound that dissolved in Ethanol, Methanol and DMSO were recorded in the range of 800-200 nm. The formation of hydrogen bond and the most possible interaction are explained using natural bond orbital (NBO) analysis. In addition, the molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis and atomic charges of the title compound were investigated using theoretical calculations. The results are discussed herein and compared with similar molecules whenever appropriate.

  4. A comprehensive spectroscopic and computational investigation of intramolecular proton transfer in the excited states of 2-(2′-hydroxyphenyl) benzoxazole and its derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Padalkar, Vikas S. [Tinctorial Chemistry Group, Institute of Chemical Technology, Matunga, Mumbai 400019 (India); Ramasami, Ponnadurai, E-mail: ramchemi@intnet.mu [Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit (Mauritius); Sekar, Nagaiyan, E-mail: n.sekar@ictmumbai.edu.in [Tinctorial Chemistry Group, Institute of Chemical Technology, Matunga, Mumbai 400019 (India)

    2014-02-15

    The excited-state intramolecular proton transfer (ESIPT) fluorescence of the 2-(2′ hydroxyphenyl) benzoxazole (HBO) and its derivatives with NO{sub 2} as electron acceptor and NH{sub 2} as electron donor at the 4 and 5 position of benzoxazole ring was studied by spectroscopic and computational methods. The changes in the electronic transition, energy levels, and orbital diagrams of the HBO derivatives were investigated using the DFT computations and they were correlated with the experimental spectral emission. The benzoxazole derivatives are fluorescent under UV-light in solution. Photophysical properties of the compounds were also studied in solvents of different polarities. Experimental absorption and emission wavelengths are in agreement with those computed with a deviation ranging between 0 and 50%. The computational methods have been useful for molecular understanding of the transitions responsible for the fluorescent spectra. -- Highlights: • Experimental photophysical properties of 2-substituted benzoxazoles in different solvents have been studied and compared with the computational data. • Compounds show dual emission due to ESIPT process and was supported by DFT and TD-DFT computations. • Experimental results and computational results are in good agreements.

  5. Theoretical spectroscopic investigations of HNS{sup q} and HSN{sup q} (q = 0, +1, −1) in the gas phase

    Energy Technology Data Exchange (ETDEWEB)

    Ben Yaghlane, S., E-mail: roberto.linguerri@u-pem.fr, E-mail: saidayagh@gmail.com; Jaidane, N.-E. [Laboratoire de Spectroscopie Atomique, Moléculaire et Applications - LSAMA, Université de Tunis El Manar, Tunis (Tunisia); Cotton, C. E.; Francisco, J. S. [Department of Chemistry and Department of Earth and Atmospheric Science, Purdue University, West Lafayette, Indiana 49707 (United States); Al Mogren, M. M. [Chemistry Department, Faculty of Science, King Saud University, PO Box 2455, Riyadh 11451 (Saudi Arabia); Linguerri, R., E-mail: roberto.linguerri@u-pem.fr, E-mail: saidayagh@gmail.com; Hochlaf, M. [Laboratoire Modélisation et Simulation Multi Echelle, Université Paris-Est, MSME UMR 8208 CNRS, 5 bd Descartes, 77454 Marne-la-Vallée (France)

    2014-06-28

    We performed accurate ab initio investigations of the geometric parameters and the vibrational structure of neutral HNS/HSN triatomics and their singly charged anions and cations. We used standard and explicitly correlated coupled cluster approaches in connection with large basis sets. At the highest levels of description, we show that results nicely approach those obtained at the complete basis set limit. Moreover, we generated the three-dimensional potential energy surfaces (3D PESs) for these molecular entities at the coupled cluster level with singles and doubles and a perturbative treatment of triple excitations, along with a basis set of augmented quintuple-zeta quality (aug-cc-pV5Z). A full set of spectroscopic constants are deduced from these potentials by applying perturbation theory. In addition, these 3D PESs are incorporated into variational treatment of the nuclear motions. The pattern of the lowest vibrational levels and corresponding wavefunctions, up to around 4000 cm{sup −1} above the corresponding potential energy minimum, is presented for the first time.

  6. Synthesis of quinoline derivatives containing pyrazole group and investigation of their crystal structure and spectroscopic properties in relation to acidity and alkalinity of mediums

    Science.gov (United States)

    Ren, Tiegang; Wang, Jie; Li, Guihui; Cheng, Hongbin; Li, Yongzhe

    2014-08-01

    Two series of quinoline derivatives containing pyrazole group were synthesized and characterized by means of 1H NMR, FT-IR, MS, elemental analysis and X-ray single crystal diffraction, and their UV-vis absorption behavior and fluorescence properties were also measured. Moreover, the effects of acetic acid and triethylamine on the spectroscopic properties of synthesized products were examined with compounds 3a and 5a as examples. It has been found that all synthesized quinoline derivatives show maximum absorption peak at 303 nm and emission peaks around 445 nm. Besides, both acetic acid and triethylamine can change the acidity of the medium, thereby influencing the UV-vis absorption spectra and fluorescence spectra of synthesized products. Moreover, theoretical investigations indicate that the integration of H+ and N atom of quinoline ring favors the formation of a new product in the presence of acetic acid, and the product obtained in this case shows a new UV-vis absorption peak at 400 nm.

  7. Spectroscopic Investigation of p-Shell Lambda Hypernuclei by the (e,e'K+) Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chunhua [Hampton Univ., Hampton, VA (United States)

    2014-08-01

    Hypernuclear spectroscopy is a powerful tool to investigate Lambda-N interaction. Compared with other Lambda hypernuclei productions, electroproduction via the (e,e'K+) reaction has the advantage of exciting states deeply inside of the hypernucleus and achieving sub-MeV energy resolution. The E05-115 experiment, which was successfully performed in 2009, is the third generation hypernuclear experiment in JLab Hall C. A new splitter magnet and electron spectrometer were installed, and beam energy of 2.344 GeV was selected in this experiment. These new features gave better field uniformity, optics quality and made the tilt method more effective in improving yield-to-background ratio. The magnetic optics of the spectrometers were carefully studied with GEANT simulation, and corrections were applied to compensate for the fringe field cross talk between the compact spectrometer magnets. The non-linear least chi-squared method was used to further calibrate the spectrometer with the events from Lambda, Sigma0 and B12Lambda and uniform magnetic optics as well as precise kinematics were achieved. Several p-shell Lambda hypernuclear spectra, including B12Λ, Be10Λ, He7Λ, were obtained with high energy resolution and good accuracy. For B12Λ, eight peaks were recognized with the resolution of ~540keV (FWHM), and the ground state binding energy was obtained as 11.529 ± 0.012(stat.) ± 0.110(syst.) MeV. Be10Λ, twelve peaks were recognized with the resolution of ~520keV (FWHM), and the binding energy of the ground state was determined as 8.710 ± 0.059(stat.) ± 0.114(syst.) MeV. For He7Λ, three peaks were recognized with the resolution of ~730keV, and the ground state binding energy was obtained as 5.510 ± 0.050(stat.) ± 0.120(syst.) MeV. Compared with the published data of B12Λ from the JLab Hall A experiment

  8. Spectroscopic and theoretical investigations of vibrational frequencies in binary unsaturated transition-metal carbonyl cations, neutrals, and anions.

    Science.gov (United States)

    Zhou, M; Andrews, L; Bauschlicher, C W

    2001-07-01

    Figure 18 presents the C-O stretching vibrational frequencies of the first-row transition-metal monocarbonyl cations, neutrals, and anions in solid neon; similar diagrams have been reported for neutral MCO species in solid argon, but three of the early assignments have been changed by recent work and one new assignment added. The laser-ablation method produces mostly neutral atoms with a few percent cations and electrons for capture to make anions; in contrast, thermal evaporation gives only neutral species. Hence, the very recent neon matrix investigations in our laboratory provide carbonyl cations and anions for comparison to neutrals on a level playing field. Several trends are very interesting. First, for all metals, the C-O stretching frequencies follow the order cations > neutrals > anions with large diagnostic 100-200 cm-1 separations, which is consistent with the magnitude of the metal d to CO pi * donation. Second, for a given charge, there is a general increase in C-O stretching vibrational frequencies with increasing metal atomic number, which demonstrates the expected decrease in the metal to CO pi * donation with increasing metal ionization potential. Some of the structure in this plot arises from the extra stability of the filled and half-filled d shell and from the electron pairing that occurs at the middle of the TM row; the plot resembles the "double-humped" graph found for the variation in properties across a row of transition metals. For the anions, the variation with metal atom is the smallest since all of the metals can easily donate charge to the CO ligand. Third, for the early transition-metal Ti, V, and Cr families, the C-O stretching frequencies decrease when going down the family, but the reverse relationship is observed for the late transition-metal Fe, Co, and Ni families. In most of the present discussion, we have referred to neon matrix frequencies; however, the argon matrix frequencies are complementary, and useful information can be

  9. The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: Implications for Spectral Line Intensity Mapping at Millimeter Wavelengths and CMB Spectral Distortions

    Science.gov (United States)

    Carilli, C. L.; Chluba, J.; Decarli, R.; Walter, F.; Aravena, M.; Wagg, J.; Popping, G.; Cortes, P.; Hodge, J.; Weiss, A.; Bertoldi, F.; Riechers, D.

    2016-12-01

    We present direct estimates of the mean sky brightness temperature in observing bands around 99 and 242 GHz due to line emission from distant galaxies. These values are calculated from the summed line emission observed in a blind, deep survey for spectral line emission from high redshift galaxies using ALMA (the ALMA spectral deep field observations “ASPECS” survey). In the 99 GHz band, the mean brightness will be dominated by rotational transitions of CO from intermediate and high redshift galaxies. In the 242 GHz band, the emission could be a combination of higher order CO lines, and possibly [C ii] 158 μm line emission from very high redshift galaxies (z ˜ 6-7). The mean line surface brightness is a quantity that is relevant to measurements of spectral distortions of the cosmic microwave background, and as a potential tool for studying large-scale structures in the early universe using intensity mapping. While the cosmic volume and the number of detections are admittedly small, this pilot survey provides a direct measure of the mean line surface brightness, independent of conversion factors, excitation, or other galaxy formation model assumptions. The mean surface brightness in the 99 GHZ band is: T B = 0.94 ± 0.09 μK. In the 242 GHz band, the mean brightness is: T B = 0.55 ± 0.033 μK. These should be interpreted as lower limits on the average sky signal, since we only include lines detected individually in the blind survey, while in a low resolution intensity mapping experiment, there will also be the summed contribution from lower luminosity galaxies that cannot be detected individually in the current blind survey.

  10. ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: implications for spectral line intensity mapping at millimeter wavelengths and CMB spectral distortions

    CERN Document Server

    Carilli, C L; Decarli, R; Walter, F; Aravena, M; Wagg, J; Popping, G; Cortes, P; Hodge, J; Weiss, A; Bertoldi, F; Riechers, D

    2016-01-01

    We present direct estimates of the mean sky brightness temperature in observing bands around 99GHz and 242GHz due to line emission from distant galaxies. These values are calculated from the summed line emission observed in a blind, deep survey for specrtal line emission from high redshift galaxies using ALMA (the 'ASPECS' survey). In the 99 GHz band, the mean brightness will be dominated by rotational transitions of CO from intermediate and high redshift galaxies. In the 242GHz band, the emission could be a combination of higher order CO lines, and possibly [CII] 158$\\mu$m line emission from very high redshift galaxies ($z \\sim 6$ to 7). The mean line surface brightness is a quantity that is relevant to measurements of spectral distortions of the cosmic microwave background, and as a potential tool for studying large-scale structures in the early Universe using intensity mapping. While the cosmic volume and the number of detections are admittedly small, this pilot survey provides a direct measure of the mean...

  11. Built-in hyperspectral camera for smartphone in visible, near-infrared and middle-infrared lights region (first report): trial products of beans-size Fourier-spectroscopic line-imager and feasibility experimental results of middle-infrared spectroscopic imaging

    Science.gov (United States)

    Ishimaru, Ichiro; Kawashima, Natsumi; Hosono, Satsuki

    2016-05-01

    We had already proposed and reported the little-finger size hyperspectral-camera that was able to be applied to visible and infrared lights. The proposed method has been expected to be mounted on smartphones for healthcare sensors, and unmanned air vehicles such as drones for antiterrorism measures or environmental measurements. In this report, we will mention the trial product of the thumb size apparatus whose lens diameter was 5[mm]. The proposed Fourier spectroscopic imager is a kind of wavefront-division and common-path phase-shift interferometers. We installed the relative inclined phase-shifter onto optical Fourier transform plane of infinity corrected optical systems. The infinity corrected optical systems was configured with an objective lens and a cylindrical imaging lens. The relative inclined phase-shifter, what was made from a thin glass less than 0.3[mm] thick, had the wedge-prism and cuboid-glass region, because half surface of a thin glass was polished at an oblique angle of around 1[deg.]. The collimated half flux of objective beams derived from single-bright points on objective surface penetrate through the wedge prism and the cuboid glass respectively. These two beams are interfered each other and form the infererogram as spatial fringe patterns. In this case, the horizontal axis on 2-dimensional light receiving device is assigned to the amount of phase-shift. And also the vertical axis is assigned to the imaging coordinates on a line view field. Thus, by installing thin phase-shifter onto optical Fourier transform plane, the line spectroscopic imager, what obtains 1 dimensional spectral character distributions, were able to be realized.

  12. The spectroscopic evolution of the recurrent nova T Pyxidis during its 2011 outburst I. The optically thick phase and the origin of moving lines in novae

    CERN Document Server

    Shore, S N; Ederoclite, A; Uthas, H

    2011-01-01

    The nova T Pyx was observed with high resolution spectroscopy (R ~ 65000) spectroscopy, beginning 1 day after discovery of the outburst and continuing through the last visibility of the star at the end of May 2011. The interstellar absorption lines of Na I, Ca II, CH, CH$^+$, and archival H I 21 cm emission line observations have been used to determine a kinematic distance. Interstellar diffuse absorption features have been used to determine the extinction independent of previous assumptions. Sample Fe-peak line profiles show the optical depth and radial velocity evolution of the discrete components. We propose a distance to T Pyx $\\geq$4.5kpc, with a strict lower limit of 3.5 kpc (the previously accepted distance). We derive an extinction, E(B-V)$\\approx0.5\\pm$0.1, that is higher than previous estimates. The first observation, Apr. 15, displayed He I, He II, C III, and N III emission lines and a maximum velocity on P Cyg profiles of the Balmer and He I lines of $\\approx$2500 km s$^{-1}$ characteristic of the...

  13. Investigation on a compact in-line multimode-single-mode-multimode fiber structure

    Science.gov (United States)

    Yin, Bin; Li, Yang; Liu, Zhi-bo; Feng, Suchun; Bai, Yunlong; Xu, Yao; Jian, Shuisheng

    2016-06-01

    We carried out a detailed investigation on a compact in-line multimode single-mode multimode (MSM) fiber structure. Both theoretical modal and experimental setup were established to demonstrate the transmission characteristics and the corresponding responses of the applied strain and temperature. The proposed structure simply involves a section of the single-mode fiber (SMF) spliced to two sections of multimode fiber (MMF) and lead-in and lead-out SMFs. The excited environment-sensitive cladding modes together with the fundamental mode in the central SMF form a typical Mach-Zehnder interferometer (MZI). We analyzed the transmission characteristics of the different length of the middle SMF and the MMF in detail. In the experiment, we obtained the extinction ratio of the MSM fiber structure based MZI comb spectrum which was up to 20 dB, and sensitivities of 0.7096 pm/με (0-2000 με) and 44.12 pm/°C (10-70 °C), which proved the potential sensing applications of the proposed fiber structure.

  14. Investigation of Tree Spectral Reflectance Characteristics Using a Mobile Terrestrial Line Spectrometer and Laser Scanner

    Directory of Open Access Journals (Sweden)

    Eetu Puttonen

    2013-07-01

    Full Text Available In mobile terrestrial hyperspectral imaging, individual trees often present large variations in spectral reflectance that may impact the relevant applications, but the related studies have been seldom reported. To fill this gap, this study was dedicated to investigating the spectral reflectance characteristics of individual trees with a Sensei mobile mapping system, which comprises a Specim line spectrometer and an Ibeo Lux laser scanner. The addition of the latter unit facilitates recording the structural characteristics of the target trees synchronously, and this is beneficial for revealing the characteristics of the spatial distributions of tree spectral reflectance with variations at different levels. Then, the parts of trees with relatively low-level variations can be extracted. At the same time, since it is difficult to manipulate the whole spectrum, the traditional concept of vegetation indices (VI based on some particular spectral bands was taken into account here. Whether the assumed VIs capable of behaving consistently for the whole crown of each tree was also checked. The specific analyses were deployed based on four deciduous tree species and six kinds of VIs. The test showed that with the help of the laser scanner data, the parts of individual trees with relatively low-level variations can be located. Based on these parts, the relatively stable spectral reflectance characteristics for different tree species can be learnt.

  15. Impedance spectroscopic investigation of the effect of thin azo-calix[4]arene film type on the cation sensitivity of the gold electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Mlika, R., E-mail: mlikarym@yahoo.fr [Laboratoire de Physique et Chimie des Interfaces (LPCI), Faculte des Sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia); Rouis, A. [Laboratoire de Physique et Chimie des Interfaces (LPCI), Faculte des Sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia); Bonnamour, I. [Universite de Lyon, Institut de Chimie et Biochimie Moleculaires et Supramoleculaires, Universite Claude Bernar, Lyon 1, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne (France); Ouada, H. Ben [Laboratoire de Physique et Chimie des Interfaces (LPCI), Faculte des Sciences de Monastir, Avenue de l' environnement, 5000 Monastir (Tunisia)

    2011-10-10

    In this work, we report the impedance spectroscopic investigation of the effect of the thin film type on the selectivity of gold/azo-calix[4]arene electrodes. For this purpose, two C1 and C3 azo-calix[4]arene derivative molecules, used as thin films, are deposited by spin-coating process on the gold surface. These thin films were first studied using contact angle measurements. This revealed a less hydrophobic character for C3 thin film, which has been attributed to the presence of hydroxyl groups at the lower rim. The sensitivity study, by Electrochemical Impedance Spectroscopy (EIS), towards Cu{sup 2+} and Eu{sup 3+} cations, has showed that the C3 thin film is more sensitive and selective towards Eu{sup 3+} than C1. This best performance is due to the presence of two ester groups acting as clips and leading to more complexation stability. The EIS results were modeled by an appropriate equivalent circuit for the aim of elucidating electrical properties of thin films. This modeling has exposed that C3 thin film presents lower ionic conductivity and limited diffusion phenomenon at the interface. Highlights: {yields} C1 and C3 azo-calix[4]arenes thin films are deposited on the gold surface. {yields} The lower hydrophobicity for C3 was attributed to the presence of hydroxyl groups. {yields} The C3 thin film is more sensitive and selective towards Eu{sup 3+} than C1 one. {yields} This best performance is due to the presence of two ester groups acting as clips.

  16. Binding affinities of Schiff base Fe(II) complex with BSA and calf-thymus DNA: Spectroscopic investigations and molecular docking analysis

    Science.gov (United States)

    Rudra, Suparna; Dasmandal, Somnath; Patra, Chiranjit; Kundu, Arjama; Mahapatra, Ambikesh

    2016-09-01

    The binding interaction of a synthesized Schiff base Fe(II) complex with biological macromolecules viz., bovine serum albumin (BSA) and calf thymus(ct)-DNA have been investigated using different spectroscopic techniques coupled with viscosity measurements at physiological pH and 298 K. Regular amendments in emission intensities of BSA upon the action of the complex indicate significant interaction between them, and the binding interaction have been characterized by Stern Volmer plots and thermodynamic binding parameters. On the basis of this quenching technique one binding site with binding constant (Kb = (7.6 ± 0.21) × 105) between complex and protein have been obtained at 298 K. Time-resolved fluorescence studies have also been encountered to understand the mechanism of quenching induced by the complex. Binding affinities of the complex to the fluorophores of BSA namely tryptophan (Trp) and tyrosine (Tyr) have been judged by synchronous fluorescence studies. Secondary structural changes of BSA rooted by the complex has been revealed by CD spectra. On the other hand, hypochromicity of absorption spectra of the complex with the addition of ct-DNA and the gradual reduction in emission intensities of ethidium bromide bound ct-DNA in presence of the complex indicate noticeable interaction between ct-DNA and the complex with the binding constant (4.2 ± 0.11) × 106 M- 1. Life-time measurements have been studied to determine the relative amplitude of binding of the complex to ct-DNA base pairs. Mode of binding interaction of the complex with ct-DNA has been deciphered by viscosity measurements. CD spectra have also been used to understand the changes in ct-DNA structure upon binding with the metal complex. Density functional theory (DFT) and molecular docking analysis have been employed in highlighting the interactive phenomenon and binding location of the complex with the macromolecules.

  17. Nondestructive spectroscopic and petrochemical investigations of Paleoarchean spherule layers from the ICDP drill core BARB5, Barberton Mountain Land, South Africa

    Science.gov (United States)

    Fritz, Jörg; Tagle, Roald; Ashworth, Luisa; Schmitt, Ralf Thomas; Hofmann, Axel; Luais, Béatrice; Harris, Phillip D.; Hoehnel, Desirée; Özdemir, Seda; Mohr-Westheide, Tanja; Koeberl, Christian

    2016-12-01

    A Paleoarchean impact spherule-bearing interval of the 763 m long International Continental Scientific Drilling Program (ICDP) drill core BARB5 from the lower Mapepe Formation of the Fig Tree Group, Barberton Mountain Land (South Africa) was investigated using nondestructive analytical techniques. The results of visual observation, infrared (IR) spectroscopic imaging, and micro-X-ray fluorescence (μXRF) of drill cores are presented. Petrographic and sedimentary features, as well as major and trace element compositions of lithologies from the micrometer to kilometer-scale, assisted in the localization and characterization of eight spherule-bearing intervals between 512.6 and 510.5 m depth. The spherule layers occur in a strongly deformed section between 517 and 503 m, and the rocks in the core above and below are clearly less disturbed. The μXRF element maps show that spherule layers have similar petrographic and geochemical characteristics but differences in (1) sorting of two types of spherules and (2) occurrence of primary minerals (Ni-Cr spinel and zircon). We favor a single impact scenario followed by postimpact reworking, and subsequent alteration. The spherule layers are Al2O3-rich and can be distinguished from the Al2O3-poor marine sediments by distinct Al-OH absorption features in the short wave infrared (SWIR) region of the electromagnetic spectrum. Infrared images can cover tens to hundreds of square meters of lithologies and, thus, may be used to search for Al-OH-rich spherule layers in Al2O3-poor sediments, such as Eoarchean metasediments, where the textural characteristics of the spherule layers are obscured by metamorphism.

  18. Binding affinities of Schiff base Fe(II) complex with BSA and calf-thymus DNA: Spectroscopic investigations and molecular docking analysis.

    Science.gov (United States)

    Rudra, Suparna; Dasmandal, Somnath; Patra, Chiranjit; Kundu, Arjama; Mahapatra, Ambikesh

    2016-09-05

    The binding interaction of a synthesized Schiff base Fe(II) complex with biological macromolecules viz., bovine serum albumin (BSA) and calf thymus(ct)-DNA have been investigated using different spectroscopic techniques coupled with viscosity measurements at physiological pH and 298K. Regular amendments in emission intensities of BSA upon the action of the complex indicate significant interaction between them, and the binding interaction have been characterized by Stern Volmer plots and thermodynamic binding parameters. On the basis of this quenching technique one binding site with binding constant (Kb=(7.6±0.21)×10(5)) between complex and protein have been obtained at 298K. Time-resolved fluorescence studies have also been encountered to understand the mechanism of quenching induced by the complex. Binding affinities of the complex to the fluorophores of BSA namely tryptophan (Trp) and tyrosine (Tyr) have been judged by synchronous fluorescence studies. Secondary structural changes of BSA rooted by the complex has been revealed by CD spectra. On the other hand, hypochromicity of absorption spectra of the complex with the addition of ct-DNA and the gradual reduction in emission intensities of ethidium bromide bound ct-DNA in presence of the complex indicate noticeable interaction between ct-DNA and the complex with the binding constant (4.2±0.11)×10(6)M(-1). Life-time measurements have been studied to determine the relative amplitude of binding of the complex to ct-DNA base pairs. Mode of binding interaction of the complex with ct-DNA has been deciphered by viscosity measurements. CD spectra have also been used to understand the changes in ct-DNA structure upon binding with the metal complex. Density functional theory (DFT) and molecular docking analysis have been employed in highlighting the interactive phenomenon and binding location of the complex with the macromolecules.

  19. Spectroscopic investigations on the effect of humic acid on the formation and solubility of secondary solid phases of Ln2(CO3)3

    Institute of Scientific and Technical Information of China (English)

    Stella Antoniou; Ioannis Pashalidis; Andre Gessner; Michael U Kumke

    2011-01-01

    The formation of secondary Ln(Ⅲ) solid phases (e.g., Nd2(CO3)3 and Sm2(CO3)3) was studied as a function of the humic acid concentration in 0.1 mol/L NaClO4 aqueous solution in the neutral pH range (5-6.5). The solid phases under investigation were prepared by alkaline precipitation under 100% CO2 atmosphere and characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), time-resolved laser fluorescence spectroscopy (TRLFS), diffuse reflectance ultraviolet-visible (DR-UV-Vis), Raman spectroscopy, and solubility measurements. The spectroscopic data obtained indicated that Nd2(CO3)3 and Sm2(CO3)3 were stable and remained the solubility limiting solid phases even in the presence of increased humic acid concentration (0.5 g/L) in solution.Upon base addition in the Ln(Ⅲ)-HA system, decomplexation of the previously formed Ln(Ⅲ)-humate complexes and precipitation of two distinct phases occurred, the inorganic (Ln2(CO3)3) and the organic phase (HA), which was adsorbed on the particle surface of the former.Nevertheless, humic acid affected the particle size of the solid phases. Increasing humic acid concentration resulted in decreasing crystallite size of the Nd2(CO3)3 and increasing crystallite size of the Sm2(CO3)3 solid phase, and affected inversely the solubility of the solid phases.However, this impact on the solid phase properties was expected to be of minor relevance regarding the chemical behavior and migration of trivalent lanthanides and actinides in the geosphere.

  20. NMR, FT-IR, Raman and UV-Vis spectroscopic investigation and DFT study of 6-Bromo-3-Pyridinyl Boronic Acid

    Science.gov (United States)

    Dikmen, Gökhan; Alver, Özgür

    2015-11-01

    Possible stable conformers and geometrical molecular structures of 6-Bromo-3-Pyridinyl Boronic acid (6B3PBA; C5H5BBrNO2) were studied experimentally and theoretically using FT-IR and Raman spectroscopic methods. FT-IR and Raman spectra were recorded in the region of 4000-400 cm-1 and 3700-400 cm-1, respectively. The structural properties were investigated further, using 1H, 13C, 1H coupled 13C, HETCOR, COSY and APT NMR techniques. The optimized geometric structures were searched by Becke-3-Lee-Yang-Parr (B3LYP) hybrid density functional theory method with 6-311++G(d, p) basis set. Vibrational wavenumbers of 6B3PBA were calculated whereby B3LYP density functional methods including 6-311++G(d, p), 6-311G(d, p), 6-311G(d), 6-31G(d, p) and 6-31G(d) basis sets. The comparison of the experimentally and theoretically obtained results using mean absolute error and experimental versus calculated correlation coefficients for the vibrational wavenumbers indicates that B3LYP method with 6-311++G(d, p) gives more satisfactory results for predicting vibrational wavenumbers when compared to the 6-311G(d, p), 6-311G(d), 6-31G(d, p) and 6-31G(d) basis sets. However, this method and none of the mentioned methods here seem suitable for the calculations of OH stretching modes, most likely because increasing unharmonicity in the high wave number region and possible intra and inter molecular interactions at OH edges lead some deviations between experimental and theoretical results. Moreover, reliable vibrational assignments were made on the basis of total energy distribution (TED) calculated using scaled quantum mechanical (SQM) method.

  1. Spectroscopic investigation of new water soluble Mn(II)(2) and Mg(II)(2) complexes for the substrate binding models of xylose/glucose isomerases.

    Science.gov (United States)

    Patra, Ayan; Bera, Manindranath

    2014-01-30

    In methanol, the reaction of stoichiometric amounts of Mn(OAc)(2)·4H(2)O and the ligand H(3)hpnbpda [H(3)hpnbpda=N,N'-bis(2-pyridylmethyl)-2-hydroxy-1,3-propanediamine-N,N'-diacetic acid] in the presence of NaOH, afforded a new water soluble dinuclear manganese(II) complex, [Mn2(hpnbpda)(μ-OAc)] (1). Similarly, the reaction of Mg(OAc)(2)·4H(2)O and the ligand H3hpnbpda in the presence of NaOH, in methanol, yielded a new water soluble dinuclear magnesium(II) complex, [Mg2(hpnbpda)(μ-OAc)(H2O)2] (2). DFT calculations have been performed for the structural optimization of complexes 1 and 2. The DFT optimized structure of complex 1 shows that two manganese(II) centers are in a distorted square pyramidal geometry, whereas the DFT optimized structure of complex 2 reveals that two magnesium(II) centers adopt a six-coordinate distorted octahedral geometry. To understand the mode of substrate binding and the mechanistic details of the active site metals in xylose/glucose isomerases (XGI), we have investigated the binding interactions of biologically important monosaccharides d-glucose and d-xylose with complexes 1 and 2, in aqueous alkaline solution by a combined approach of FTIR, UV-vis, fluorescence, and (13)C NMR spectroscopic techniques. Fluorescence spectra show the binding-induced gradual decrease in emission of complexes 1 and 2 accompanied by a significant blue shift upon increasing the concentration of sugar substrates. The binding modes of d-glucose and d-xylose with complex 2 are indicated by their characteristic coordination induced shift (CIS) values in (13)C NMR spectra for C1 and C2 carbon atoms.

  2. Synthesis, characterization, and spectroscopic investigation of new iron(III) and copper(II) complexes of a carboxylate rich ligand and their interaction with carbohydrates in aqueous solution.

    Science.gov (United States)

    Stewart, Christopher D; Arman, Hadi; Bawazir, Huda; Musie, Ghezai T

    2014-10-20

    New tetra-iron(III) (K4[1]·25H2O·(CH3)2CO and K3[2]·3H2O·(OH)) and di-copper(II) (Na3[3]·5H2O) complexes as carbohydrate binding models have been synthesized and fully characterized used several techniques including single crystal X-ray crystallography. Whereas K4[1]·25H2O·(CH3)2CO and Na3[3]·5H2O are completely water-soluble, K3[2]·3H2O·(OH) is less soluble in all common solvents including water. The binding of substrates, such as d-mannose, d-glucose, d-xylose, and xylitol with the water-soluble complexes in different reaction conditions were investigated. In aqueous alkaline media, complexes K4[1]·25H2O·(CH3)2CO and Na3[3]·5H2O showed coordination ability toward the applied substrates. Even in the presence of stoichiometric excess of the substrates, the complexes form only 1:1 (complex/substrate) molar ratio species in solution. Apparent binding constants, pKapp, values between the complexes and the substrates were determined and specific mode of substrate binding is proposed. The pKapp values showed that d-mannose coordinates strongest to K4[1]·25H2O·(CH3)2CO and Na3[3]·5H2O. Syntheses, characterizations and detailed substrate binding study using spectroscopic techniques and single crystal X-ray diffraction are reported.

  3. The microscopic investigation of structures of moving flux lines by neutron and muon techniques

    Indian Academy of Sciences (India)

    E M Forgan; D Charalambous; P G Kealey

    2002-05-01

    We have used a variety of microscopic techniques to reveal the structure and motion of flux line arrangements, when the flux lines in low c type II superconductors are caused to move by a transport current. Using small-angle neutron scattering by the flux line lattice (FLL), we are able to demonstrate directly the alignment by motion of the nearest-neighbor FLL direction. This tends to be parallel to the direction of flux line motion, as had been suspected from two-dimensional simulations. We also see the destruction of the ordered FLL by plastic flow and the bending of flux lines. Another technique that our collaboration has employed is the direct measurement of flux line motion, using the ultra-high-resolution spectroscopy of the neutron spin-echo technique to observe the energy change of neutrons diffracted by moving flux lines. The muon spin rotation (SR) technique gives the distribution of values of magnetic field within the FLL. We have recently succeeded in performing SR measurements while the FLL is moving. Such measurements give complementary information about the local speed and orientation of the FLL motion. We conclude by discussing the possible application of this technique to thin film superconductors.

  4. Synthesis, spectroscopic characterization, electrochemical behavior and computational analysis of mixed diamine ligand gold(III) complexes: antiproliferative and in vitro cytotoxic evaluations against human cancer cell lines.

    Science.gov (United States)

    Al-Jaroudi, Said S; Monim-ul-Mehboob, M; Altaf, Muhammad; Al-Saadi, Abdulaziz A; Wazeer, Mohammed I M; Altuwaijri, Saleh; Isab, Anvarhusein A

    2014-12-01

    The gold(III) complexes of the type [(DACH)Au(en)]Cl3, 1,2-Diaminocyclohexane ethylenediamine gold(III) chloride [where 1,2-DACH = cis-, trans-1,2- and S,S-1,2diaminocyclohexane and en = ethylenediamine] have been synthesized and characterized using various analytical and spectroscopic techniques including elemental analysis, UV-Vis and FTIR spectra; and solution as well as solid-state NMR measurements. The solid-state (13)C NMR shows that 1,2-diaminocyclohexane (1,2-DACH) and ethylenediamine (en) are strongly bound to the gold(III) center via N donor atoms. The stability of the mixed diamine ligand gold(III) was determined by (1)H and (13)C NMR spectra. Their electrochemical behavior was studied by cyclic voltammetry. The structural details and relative stabilities of the four possible isomers of the complexes were also reported at the B3LYP/LANL2DZ level of theory. The coordination sphere of these complexes around gold(III) center adopts distorted square planar geometry. The computational study also demonstrates that trans- conformations is slightly more stable than the cis-conformations. The antiproliferative effects and cytotoxic properties of the mixed diamine ligand gold(III) complexes were evaluated in vitro on human gastric SGC7901 and prostate PC3 cancer cells using MTT assay. The antiproliferative study of the gold(III) complexes on PC3 and SGC7901 cells indicate that complex 1 is the most effective antiproliferative agent among mixed ligand based gold(III) complexes 1-3. The IC50 data reveal that the in vitro cytotoxicity of complexes 1 and 3 against SGC7901 cancer cells are fairly better than that of cisplatin.

  5. Investigation of an X-band magnetically insulated transmission line oscillator

    Institute of Scientific and Technical Information of China (English)

    Fan Yu-Wei; Zhong Hui-Huang; Li Zhi-Qiang; Shu Ting; Yang Han-Wu; Yang Jian-Hua; Wang Yong; Luo Ling; Zhao Yan-Song

    2008-01-01

    An X-band magnetically insulated transmission line oscillator (MILO) is designed and investigated numerically and experimentally for the first time.The X-band MILO is optimized in detail with KARAT code.In simulation,the X-band MILO,driven by a 720kV,53kA electron beam,comes to a nonlinear steady state in 4.0ns.High-power microwaves (HPM) of TEM mode is generated with an average power of 4.1 GW,a frequency of 9.3 GHz,and power conversion efficiency of 10.8% in durations of {)-40 ns.The device is fabricated according to the simulation results.In experiments,when the voltage is 400 kV and the current is 50 kA,the radiated microwave power reaches about 110 MW and the dominating frequency is 9.7GHz.Because the surfaces of the cathode end and the beam dump are destroyed,the diode voltage cannot increase continuously.However,when the diode voltage is 400 kV,the average power output is obtained to be 700 MW in simulation.The impedance of the device is clearly smaller than the simulation prediction.Moreover,the duration of the microwave pulse is obviously shorter than that of the current pulse.The experimental results are greatly different from the simulation predictions.The preliminary analyses show that the generations of the anode plasma,the cathode flare and the anode flare are the essential cause for the remarkable deviation of the experimental results from the simulation predictions.

  6. Final Scientific Report: Experimental Investigation of Reconnection in a Line-tied Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Forest, Cary [Univ. of Wisconsin, Madison, WI (United States)

    2016-10-25

    This grant used funding from the NSF/DoE Partnership on Plasma Science to investigate magnetic reconnection phenomena in a line-tied pinch experiment. The experiment was upgraded from a previous device intended to study fusion plasma-related instabilities to a new configuration capable of studying a number of new, previously unstudied configurations. A high spatial and time resolution array of magnetic probes was constructed to measure time evolving structures present as instability and turbulence developed. The most important new equilibrium made possible by this grant was a Zero-Net-Current equilibrium that models the footpoint twisting of solar flux tubes that occurs prior to solar eruptions (flares and coronal mass ejections). This new equilibrium was successfully created in the lab, and it exhibited a host of instabilities. In particular, at low current when the equilibrium was not overly stressed, a saturated internal kink mode oscillation was observed. At high current, 2 D magnetic turbulence developed which we attribute to the lack of a equilibrium brought about by a subcritical transition to turbulence. A second set of experiments involved the turbulent interactions of a collection of flux tubes all being twisted independently, a problem known as the Parker Problem. Current profiles consisting of 2, 3 and 4 guns were used to impose a fine scale drive, and resulted in a new experimental platform in which the injection scale of the magnetic turbulence could be controlled. First experiments in this configuration support the conclusion that an inverse cascade of magnetic energy occurred which self-organized the plasma into a nearly axisymmetric current distribution.

  7. Spectroscopic Line Parameters of - and Hydrogen-Broadened 12C16O Transitions in the 3-0 Band from 6270 wn to 6402 wn.

    Science.gov (United States)

    Reed, Zachary; Hodges, Joseph T.

    2016-06-01

    We present helium- and hydrogen-broadened linewidths, pressure-induced shifts, and collisional narrowing coefficients for selected lines in the P- and R- branch of the second overtone (3-0) band of CO, spanning from 6270 wn to 6402 wn. The contribution of speed dependent effects and partial correlation between velocity-changing and dephasing collisions on the foreign broadened line shapes are also discussed. The data were obtained using the frequency-stabilized cavity ringdown spectroscopy technique. Spectra were collected at room temperature over a pressure range from 13.3 kPa to 100 kPa. The spectrum frequency axis is referenced via an optical frequency comb to a Cs clock, which provides pressure shifting values with uncertainties as low as 100 kHz/atm. The spectra exhibited signal-to-noise ratios as high as 20,000:1, which enables rigorous tests of theoretical line profiles through multi-spectrum least squares data analysis. The partially correlated, quadratic-speed-dependent Nelkin Ghatak profile gives a quality of fit mostly commensurate with the high spectrum signal-to-noise and minimizes structural residuals.

  8. Investigation of chromosome abnormalities and early embryonic mortality in goose lines.

    Science.gov (United States)

    Liptói, Krisztina; Hidas, A; Rouvier, R

    2005-01-01

    Early embryonic mortality and chromosome abnormalities were studied in three goose lines: Grey Landes (line 7), White Polish (line 4) and their synthetic line (line 9). Eggs laid at the beginning, in the middle and at the end of the laying season were set. At candling at 5th day after egg set, all eggs (2847) were examined and those showing no normal embryonic development were opened 2847. Dead embryos were classified phenotypically and karyotyped. The mean ratio of embryonic mortality (EM) among fertile eggs was 9.4%, 5.2%, 7.3% in the lines 4, 7 and 9, respectively. The mean ratio of embryos with chromosomal abnormalities (CA) among the dead embryos was 8.0%, 14.8% and 13.1% in the lines 4, 7 and 9, respectively. Gander effect and layer within gander effect on embryo mortality were significant, indicating genetic factors. Father and mother of the layer effects were also significant, showing family effects. Animals producing dead embryos and embryos with chromosome abnormalities in high proportion were selected. In the selected groups the mean EM was 17.7-22.9%, and the mean CA was 11.7-34.7% among the three lines. The repetition of CA was not observed in the reproductive season of following year, while animals repeated the high EM (repeatability coefficient of 0.54). This shows that some part of EM may be resulted from other genetic factors. Ganders and layers progeny of these selected animals showed also high EM. It was concluded that culling pairs giving high EM value in their embryos could increase the average level of embryo viability and that the study of genetic determinism of that trait should be continued in geese.

  9. Investigation of the Herschel-Quincke tube concept in a rectangular lined duct

    OpenAIRE

    2001-01-01

    In this research an innovative combination of the Herschel-Quincke tubes and traditional liners is proposed for application in noise reduction of aircraft engines. The approach consists of installing Herschel-Quincke (HQ) tubes on lined rectangular ducts. An analytical model was developed to predict the effects of HQ tubes applied to rectangular lined ducts. The technique involves assuming the tube-duct interfaces as finite piston sources. These sources couple the acoustic field inside the du...

  10. INVESTIGATION OF MICROPROCESSOR CURRENT PROTECTION LINES WITH IMPROVED INDICES OF TECHNICAL PERFECTION

    Directory of Open Access Journals (Sweden)

    E. V. Buloichyk

    2014-01-01

    Full Text Available Technical perfection improvement of microprocessor current protection of distribution networks lines is provided by introduction of asymmetrical fault mode determination and fault location functions in the algorithm of its functioning. As a result of computing experiment the basic indices of the technical perfection of current protection have been obtained in the paper. The paper proves high efficiency of the proposed methods that ensure selective and proper operation in the different modes of the controlled line.

  11. Microscale Syntheses, Reactions, and 1H NMR Spectroscopic Investigations of Square Planar Macrocyclic Tetraamido-N Cu(III) Complexes Relevant to Green Chemistry

    Science.gov (United States)

    Uffelman, Erich S.; Doherty, Jonathan R.; Schulze, Carl; Burke, Amy L.; Bonnema, Kristen R.; Watson, Tanya T.; Lee, Daniel W., III

    2004-01-01

    Microscale fusions, description, and spectroscopic analysis of the reactivity of a square planar Cu(III) complex significant to green chemistry, are presented. The experiment also includes nine focal points on which pre-lab and post-lab questions are based, and the final exams reflect the students' comprehension of these and other features of…

  12. A multi-epoch spectroscopic study of the BAL quasar APM 08279+5255 II. Emission- and absorption-line variability time lags

    CERN Document Server

    Saturni, F G; Vagnetti, F; Perna, M; Dadina, M

    2015-01-01

    The study of high-redshift bright quasars is crucial to gather information about the history of galaxy assembly and evolution. Variability analyses can provide useful data on the physics of the quasar processes and their relation with the host galaxy. In this study, we aim at measuring the black hole mass of the bright lensed BAL QSO APM 08279+5255 at $z=3.911$ through reverberation mapping, and at updating and extending the monitoring of its C IV absorption line variability. Thanks to 138 R-band photometric data and 30 spectra available over 16 years of observations, we perform the first reverberation mapping of the Si IV and C IV emission lines for a high-luminosity quasar at high redshift. We also cross-correlate the C IV absorption equivalent width variations with the continuum light curve, in order to estimate the recombination time lags of the various absorbers and infer the physical conditions of the ionised gas. We find a reverberation-mapping time lag of $\\sim 900$ rest-frame days for both Si IV and ...

  13. SCHEDULING OF PACKAGING LINES IN THE PROCESS INDUSTRY - AN EMPIRICAL-INVESTIGATION

    NARCIS (Netherlands)

    VANDAM, P; GAALMAN, G; SIERKSMA, G

    1993-01-01

    In the process industry, homogeneous products have to be packed. For an unpacked product (milk, paint), a variety of packaging materials (glass, tin) and packaging sizes (1/2 litre, 1 kilo) are available. Generally, the packaging lines are used for various products (milk, buttermilk) in one type of

  14. Investigating Gamma-Ray Lines from Dark Matter with Future Observatories

    NARCIS (Netherlands)

    L. Bergström; G. Bertone; J. Conrad; C. Farnier; C. Weniger

    2012-01-01

    We study the prospects for studying line features in gamma-ray spectra with upcoming gamma-ray experiments, such as HESS-II, the Cherenkov Telescope Array (CTA), and the GAMMA-400 satellite. As an example we use the narrow feature at 130 GeV seen in public data from the Fermi-LAT satellite. We found

  15. A liquid contact line receding on a soft gel surface : dip-coating geometry investigation

    CERN Document Server

    Kajiya, Tadashi; Royon, Laurent; Daerr, Adrian; Receveur, Mathieu; Limat, Laurent

    2015-01-01

    We studied the dynamics of a liquid contact line receding on a hydrophobic soft gel (SBS-paraffin). In order to realize a well-defined geometry with an accurate control of velocity, a dip-coating setup was implemented. Provided that the elastic modulus is small enough, a significant deformation takes place near the contact line, which in turn drastically influences the wetting behaviour. Depending on the translation velocity of the substrate, the contact line exhibits different regimes of motions. Continuous motions are observed at high and low velocities, meanwhile two types of stick-slip motion, periodic and erratic, appear at intermediate velocities. We suggest that the observed transitions could be explained in terms of the competition between different frequencies, i.e., the frequency of the strain field variation induced by the contact line motion and the crossover frequency of the gel related to the material relaxation. Our results provide systematic views on how the wetting of liquid is modified by th...

  16. Using an On-Line Tool To Investigate Chemical Engineering Seniors' Concept of the Design Process.

    Science.gov (United States)

    Streveler, Ruth A.; Miller, Ronald L.; Boyd, Thomas M.

    In this study, multidimensional scaling (MDS) was used to measure how 23 chemical engineering seniors categorized key design terms at the beginning and end of a capstone design course. An on-line method was developed to collect the MDS data. The results suggest that some important design concepts were not well understood, even at the end of the…

  17. Investigation of Freeze-Linings in Copper-Containing Slag Systems: Part I. Preliminary Experiments

    Science.gov (United States)

    Fallah-Mehrjardi, Ata; Hayes, Peter C.; Jak, Evgueni

    2013-06-01

    Slag freeze-linings are increasingly used in industrial pyrometallurgical processes to insure that furnace integrity is maintained in aggressive high-temperature environments. Most previous studies of freeze-linings have analyzed the formation of slag deposits based solely on heat-transfer models. The focus of the present research is to determine the impact of slag chemistry and local process conditions on the microstructures, thickness, stability, and heat-transfer characteristics of the frozen deposit at steady-state conditions. The formation of the freeze-linings is studied under controlled laboratory conditions using an air-cooled "cold-finger" technique for Cu-Fe-Si-Al-O slag at equilibrium with metallic copper relevant to the industrial copper smelting processes. The phase assemblages and microstructures of the deposits formed in the cold-finger experiments differ significantly from those expected from phase equilibrium considerations. The freeze-lining deposits have been found, in general, to consist of several layers. Starting from the cold finger, these layers consist of glass; glass with microcrystalline precipitates; closed crystalline layer; and open crystalline layer. Even at steady-state conditions, there was no primary phase sealing layer of delafossite [Cu2O · (Al, Fe)2O3] present at the deposit/liquid interface—these observations differ markedly from those expected from phase equilibrium considerations. The findings have significant practical implications, and potential for the improved design and operation of industrial metallurgical furnaces.

  18. Investigation of the collision line broadening problem as applicable to the NASA Optical Plume Anomaly Detection (OPAD) system, phase 1

    Science.gov (United States)

    Dean, Timothy C.; Ventrice, Carl A.

    1995-05-01

    As a final report for phase 1 of the project, the researchers are submitting to the Tennessee Tech Office of Research the following two papers (reprinted in this report): 'Collision Line Broadening Effects on Spectrometric Data from the Optical Plume Anomaly System (OPAD),' presented at the 30th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 27-29 June 1994, and 'Calculation of Collision Cross Sections for Atomic Line Broadening in the Plume of the Space Shuttle Main Engine (SSME),' presented at the IEEE Southeastcon '95, 26-29 March 1995. These papers fully state the problem and the progress made up to the end of NASA Fiscal Year 1994. The NASA OPAD system was devised to predict concentrations of anomalous species in the plume of the Space Shuttle Main Engine (SSME) through analysis of spectrometric data. The self absorption of the radiation of these plume anomalies is highly dependent on the line shape of the atomic transition of interest. The Collision Line Broadening paper discusses the methods used to predict line shapes of atomic transitions in the environment of a rocket plume. The Voigt profile is used as the line shape factor since both Doppler and collisional line broadening are significant. Methods used to determine the collisional cross sections are discussed and the results are given and compared with experimental data. These collisional cross sections are then incorporated into the current self absorbing radiative model and the predicted spectrum is compared to actual spectral data collected from the Stennis Space Center Diagnostic Test Facility rocket engine. The second paper included in this report investigates an analytical method for determining the cross sections for collision line broadening by molecular perturbers, using effective central force interaction potentials. These cross sections are determined for several atomic species with H2, one of the principal constituents of the SSME plume environment, and compared with experimental data.

  19. Investigation of potential driver modules and transmission lines for a high frequency power system on the space station

    Science.gov (United States)

    Brush, Harold T.

    1986-01-01

    The feasibility of using Series Resonant Inverter as the driver module for high frequency power system on the Space Station was assessed. The performance of the Series Resonant Inverter that was used in the testing of the single-phase, 2.0-kw resonant AC power system breadboard is summarized. The architecture is descirbed and the driver modules of the 5.0 kw AC power system breadboard are analyzed. An investigation of the various types of transmission lines is continued. Measurements of equivalent series resistor and inductor and equivalent parallel capacitors are presented. In particular, a simplified approach is utilized to describe the optimal transmission line.

  20. Investigation of Stomata Densities in Pea (Pisum sativum L. Lines/Cultivars

    Directory of Open Access Journals (Sweden)

    Reyhan Karayel

    2006-01-01

    Full Text Available This study was conducted to determine, if stomata density can be used as a criterion in cultivar differentiation or not. In this study, density of stomatas in stipula and abaxial and adaxial surface of leaflets was determined in the flowering and pod set period of 23 pea cultivars and lines that were sowed as wintertime for 2 years. The effect of years on the stomata density in other parts sections except for the stomata numbers in stipula and leaflet adaxial surface were determined on the level of statistical significance. In pod setting period, stomata numbers were higher compared to the flowering period. Stomata number in leaf section of the 5 cultivars used in the trial is in general higher than those of the lines. The determination of year x genotype interaction in the study shows that there is not enough evidence for using this characteristic for cultivar differentiation.

  1. Investigation of Motion of Two Hinged Bodies Moored by Mooring Lines in Waves

    Institute of Scientific and Technical Information of China (English)

    纪亨腾; 范菊; 黄祥鹿

    2002-01-01

    In this paper, the motions are studied of a multi-body which is composed of two plates hinged together and mooredby eight mooring lines in regular waves. The experimental results are compared with computational results. The linear po-tential theory and the perturbation method are combined to study this complicated system. The former is used to calculatethe wave forces acting on the plates and the motion responses of them, while the latter is used to describe the dynamiccharacter of the eight mooring lines coupled with the two hinged plates. Some response results of each plate are presentedand comparisons between calculated results and experimental data are given. All the calculations are confined to regularbeam waves.

  2. Validation of an in-line Raman spectroscopic method for continuous active pharmaceutical ingredient quantification during pharmaceutical hot-melt extrusion.

    Science.gov (United States)

    Saerens, L; Segher, N; Vervaet, C; Remon, J P; De Beer, T

    2014-01-02

    A calibration model for in-line API determination was developed based on Raman spectra collected during hot-melt extrusion. This predictive model was validated by calculating the accuracy profile based on the analysis results of validation experiments. Furthermore, based on the data of the accuracy profile, the measurement uncertainty was determined. Finally, the robustness of the model was evaluated. A Raman probe was implemented in the die of a twin-screw extruder, to monitor the drug concentration during extrusion of physical mixtures containing 15, 20, 25, 30 and 35% (w/w) metoprolol tartrate (MPT) in Eudragit(®) RS PO, an amorphous copolymer of acrylic and methacrylic acid esters with a low content of quaternary ammonium groups, which are present as salts. Several different calibration models for the prediction of the MPT content were developed, based on the use of single spectra or averaged spectra, and using partial least squares (PLS) regression or multivariate curve resolution (MCR). These predictive models were validated by extruding and monitoring mixtures containing 17.5, 22.5, 25.0, 27.5 and 32.5% (w/w) MPT. Each validated concentration was monitored on three different days, by two different operators. The β-expectation tolerance intervals were calculated for each model and for each of the validated MPT concentration levels (β was set at 95%), and acceptance limits were set at 10% (relative bias), indicating that at least 95% of future measurements should not deviate more than 10% from the true value. The only model where these acceptance limits were not exceeded was the MCR model based on averaged Raman spectra. The uncertainty measurements for this model showed that the unknown true value can be found at a maximum of ±7.00% around the measured result, with a confidence level of 95%. The robustness of this model was evaluated via an experimental design varying throughput, screw speed and barrel temperature. The robustness designs showed no

  3. Investigation of the stochastic subspace identification method for on-line wind turbine tower monitoring

    Science.gov (United States)

    Dai, Kaoshan; Wang, Ying; Lu, Wensheng; Ren, Xiaosong; Huang, Zhenhua

    2017-04-01

    Structural health monitoring (SHM) of wind turbines has been applied in the wind energy industry to obtain their real-time vibration parameters and to ensure their optimum performance. For SHM, the accuracy of its results and the efficiency of its measurement methodology and data processing algorithm are the two major concerns. Selection of proper measurement parameters could improve such accuracy and efficiency. The Stochastic Subspace Identification (SSI) is a widely used data processing algorithm for SHM. This research discussed the accuracy and efficiency of SHM using SSI method to identify vibration parameters of on-line wind turbine towers. Proper measurement parameters, such as optimum measurement duration, are recommended.

  4. Nano-spectroscopic imaging of intermolecular structure, coupling and dynamics

    CERN Document Server

    Pollard, Benjamin; Hinrichs, Karsten; Raschke, Markus B

    2013-01-01

    Molecular self-assembly, the function of biomembranes, and the performance of organic solar cells rely on molecular interactions on the nanoscale. The understanding and design of such intrinsic or engineered heterogeneous functional soft matter has long been impeded by a lack of spectroscopic tools with sufficient nanometer spatial resolution, attomolar sensitivity, and intermolecular spectroscopic specificity. We implement vibrational scattering-scanning near-field optical microscopy ($s$-SNOM) in a multi-spectral modality with unprecedented spectral precision to investigate the structure-function relationship in nano-phase separated block-copolymers. We use a vibrational resonance as a sensitive reporter of the local chemical environment and resolve, with few nanometer spatial resolution and 0.2 cm$^{-1}$ spectral precision, spectral Stark shifts and line broadening correlated with molecular-scale morphologies. By creating images of solvatochromic vibrational shifts we discriminate local variations in elect...

  5. Investigating a signature of temozolomide resistance in GBM cell lines using metabolomics.

    Science.gov (United States)

    St-Coeur, Patrick-Denis; Poitras, Julie J; Cuperlovic-Culf, Miroslava; Touaibia, Mohamed; Morin, Pier

    2015-10-01

    Glioblastoma multiforme (GBM) is the most common form of malignant glioma. Current therapeutic approach to treat this malignancy involves a combination of surgery, radiotherapy and chemotherapy with temozolomide. Numerous mechanisms contributing to inherent and acquired resistance to this chemotherapeutic agent have been identified and can lead to treatment failure. This study undertook a metabolomics-based approach to characterize the metabolic profiles observed in temozolomide-sensitive and temozolomide-resistant GBM cell lines as well as in a small sub-set of primary GBM tumors. This approach was also utilized to explore the metabolic changes modulated upon cell treatment with temozolomide and lomeguatrib, an MGMT inhibitor with temozolomide-sensitizing potential. Metabolites previously explored for their potential role in chemoresistance including glucose, citrate and isocitrate demonstrated elevated levels in temozolomide-resistant GBM cells. In addition, a signature of metabolites comprising alanine, choline, creatine and phosphorylcholine was identified as up-regulated in sensitive GBM cell line across different treatments. These results present the metabolic profiles associated with temozolomide response in selected GBM models and propose interesting leads that could be leveraged for the development of therapeutic or diagnostic tools to impact temozolomide response in GBMs.

  6. Experimental investigation on chill-down process of cryogenic flow line

    Science.gov (United States)

    Jin, Lingxue; Park, Changgi; Cho, Hyokjin; Lee, Cheonkyu; Jeong, Sangkwon

    2016-10-01

    This paper describes the cryogenic chill-down experiments that are conducted on a 12.7 mm outer diameter, 1.25 mm wall thickness and 7 m long stainless steel horizontal pipe with liquid nitrogen (LN2). The pipe is vacuum insulated during the experiment to minimize the heat leak from room temperature and to enable one to numerically simulate the process easily. The temperature and the pressure profiles of the chill-down line are obtained at the location which is 5.5 m in a distance from the pipe inlet. The mass flux range is approximately from 19 kg/m2 s to 49 kg/m2 s, which corresponds to the Reynolds numbers range from 1469 to 5240. The transient histories of temperature, pressure and mass flow rate during the line chill-down process are monitored, and the heat transfer coefficient and the heat flux are computed by an inverse problem solving method. The amplitude of the pressure oscillation and the oscillating period become larger and longer at higher pressure conditions. In the low mass flux conditions, the critical heat flux in horizontal pipes is not sensitive to mass flux, and is higher than that in vertical pipes. Kutateladze's correlation with the constant coefficient, B = 0.029 , well matches the experimental data in the current work. In nucleate flow boiling regime, heat transfer coefficient, h , is proportional to (q″)n , and n is equal to 0.7.

  7. Radiobiological investigations at tumor cell lines by exploiting chrono-biological aspects of chronological dose distributions

    CERN Document Server

    Ulmer, W

    2011-01-01

    Using 31P-NMR spectroscopy the chronological behavior of the ATP-metabolism of the tumor spheroids C3H-MA, 9L-Gliome and the mono-layer L1210 has been analyzed via decrease of the {\\beta}-peak. All three cell lines show characteristic periods, and a homeostatic control cannot be recognized. Essential components of these periods are circadian (i.e. one day), circa-semiseptan (i.e. 3.5 days) and circa-septan (i.e. one week). The determination of the survival fractions provides an optimum exploitation of radiation damages, when the ATP-concentration assumes a maximum value. This optimum is reached, when all three cycles exhibit the ATP maximum, which is only possible by accounting for the circa-septan rhythm. The goal of this study is to elaborate an optimal fractionation scheme with regard to the irradiation of tumors.

  8. A new investigation on drift of base-line value in geomagnetic observation

    Science.gov (United States)

    Yang, Dong-Mei; Gao, Yu-Fen; Zhao, Yong-Fen; Huang, Wei-Bei

    1997-07-01

    A new explanation on drift of base-line (BL) value in geomagnetic observation was presented by means of detailed analysis on BL value of H-variometer at Tianshui Observatory from 1991 to 1995, in association with some numerical simulation. It was confirmed that drift does not always exist. For variometers running normally for many years, drift appears to be zero. The temperature-dependence of BL value is reversible below a certain temperature but irreversible above it. This irreversibility is the main reason that causes the BL value to show a monotonous declination with time, which has been mistaken for the drift in the past. As to the H-variometer at Tianshui Observatory, no drift exists in BL value in these years. A new method was introduced to study the BL value variation with temperature by separating it into three parts.

  9. The sinusoidal lining cells in "normal" human liver. A scanning electron microscopic investigation

    DEFF Research Database (Denmark)

    Horn, T; Henriksen, Jens Henrik Sahl; Christoffersen, P

    1986-01-01

    The scanning electron microscopic was used to study the fenestrations of human liver sinusoids. Thirteen biopsies, where light microscopy and transmission electron microscopy revealed normal sinusoidal architecture, were investigated. The number of fenestrae was calculated in acinar zone 3...

  10. Spectroscopic and quantum chemical investigations of substituent effects on the azo-hydrazone tautomerism and acid-base properties of arylazo pyridone dyes.

    Science.gov (United States)

    Dostanić, J; Mijin, D; Ušćumlić, G; Jovanović, D M; Zlatar, M; Lončarević, D

    2014-04-05

    A series of 5-(4-substituted arylazo)-6-hydroxy-4-methyl-3-cyano-2-pyridone dyes was synthesized and the structure of the dyes was confirmed by UV-Vis, FT-IR, (1)H NMR and (13)C NMR spectroscopic techniques. The azo-hydrazone tautomeric equilibrium was found to depend on the substituents as well as on the acidity and basicity of the media. Ionization constant, pKa, of the dyes was determined by UV-Vis spectroscopy and correlated with the Hammett substituent constants, σp and σI. The interpretation of the effect of different substituent in phenyl ring of arylazo pyridone dyes on their spectroscopic and structural properties was based on quantum chemical calculations performed by the density functional theory (DFT/M06-2X) method. The DFT calculations confirmed the existence of two forms in water solution: hydrazone form in acidic and neutral media and anionic form in basic media. The different contribution of azo and hydrazone canonical forms of anionic form is observed for dyes with electron-donating and dyes with electron-withdrawing groups. The dependence of absorption spectra and determined pKa values to the substituent type seems to be mostly due to azo/hydrazone canonical structure ratio in their anionic form. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. The photospheric solar oxygen project: IV. 3D-NLTE investigation of the 777 nm triplet lines

    CERN Document Server

    Steffen, M; Caffau, E; Ludwig, H -G; Bonifacio, P; Cayrel, R; Kučinskas, A; Livingston, W C

    2015-01-01

    The solar photospheric oxygen abundance is still widely debated. Adopting the solar chemical composition based on the "low" oxygen abundance, as determined with the use of three-dimensional (3D) hydrodynamical model atmospheres, results in a well-known mismatch between theoretical solar models and helioseismic measurements that is so far unresolved. We carry out an independent redetermination of the solar oxygen abundance by investigating the center-to-limb variation of the OI IR triplet lines at 777 nm in different sets of spectra with the help of detailed synthetic line profiles based on 3D hydrodynamical CO5BOLD model atmospheres and 3D non-LTE line formation calculations with NLTETD. The idea is to simultaneously derive the oxygen abundance,A(O), and the scaling factor SH that describes the cross-sections for inelastic collisions with neutral hydrogen relative the classical Drawin formula. The best fit of the center-to-limb variation of the triplet lines achieved with the CO5BOLD 3D solar model is clearly...

  12. Spectroscopic Parameters for Ozone and its Isotopes: Current Status, Prospects for Improvement, and the Identification of 16O16O17O and O-16O-16O-17 and O-16O-17O-16 Lines in Infrared Ground-Based and Stratospheric Solar Absorption Spectra

    Science.gov (United States)

    Rinsland, C. P.; Flaud, J.-M.; Goldman, A.; Perrin, A.; Camy-Peyret, C.; Smith, M. A. H.; Devi, V. Malathy; Benner, D. C.; Barbe, A.; Stephens, T. M.; hide

    1998-01-01

    We describe the updates to the spectroscopic parameters of ozone and its isotopes in the 1996 HITRAN compilation. Recent published studies not included in HITRAN are also summarized. Finally, we report the identification of infrared lines of the v(sub 3) bands of O-16O-16O-17 and O-16O-17O-16 in high-resolution solar spectra recorded by stratospheric balloon-borne and ground-based Fourier transform spectrometers.

  13. Experimental investigation of contact angle, curvature, and contact line motion in dropwise condensation and evaporation.

    Science.gov (United States)

    Gokhale, Shripad J; Plawsky, Joel L; Wayner, Peter C

    2003-03-15

    Image-analyzing interferometry is used to measure the apparent contact angle and the curvature of a drop and a meniscus during condensation and evaporation processes in a constrained vapor bubble (CVB) cell. The apparent contact angle is found to be a function of the interfacial mass flux. The interfacial velocity for the drop during condensation and evaporation is a function of the apparent contact angle and the rate of change of radius of curvature. The dependence of velocity on the apparent contact angle is consistent with Tanner's scaling equation. The results support the hypothesis that evaporation/condensation is an important factor in contact line motion. The main purpose of this article is to present the experimental technique and the data. The equilibrium contact angle for the drop is found experimentally to be higher than that for the corner meniscus. The contact angle is a function of the stress field in the fluid. The equilibrium contact angle is related to the thickness of the thin adsorbed film in the microscopic region and depends on the characteristics of the microscopic region. The excess interfacial free energy and temperature jump were used to calculate the equilibrium thickness of the thin adsorbed film in the microscopic region.

  14. An investigation of the performance of an electronic in-line pump system for diesel engines

    Institute of Scientific and Technical Information of China (English)

    FAN Li-yun; ZHU Yuan-xian; LONG Wu-qiang; MA Xiu-zhen; XUE Ying-ying

    2008-01-01

    WIT Electronic Fuel System Co.,Ltd. has developed a new fuel injector,the Electronic In-line Pump (EIP) system,designed to meet China's diesel engine emission and fuel economy regulations. It can be used on marine diesel engines and commercial vehicle engines through different EIP systems. A numerical model of the EIP system was built in the AMESim environment for the purpose of creating a design tool for engine application and system optimization. The model was used to predict key injection characteristics under different operating conditions,such as injection pressure,injection rate,and injection duration. To validate these predictions,experimental tests were conducted under the conditions that were modeled. The results were quite encouraging and in agreement with model predictions. Additional experiments were conducted to study the injection characteristics of the EIP system. These results show that injection pressure and injection quantity are insensitive to injection timing variations,this is due to the design of the constant velocity cam profile. Finally,injection quantity and pressure vs. pulse width at different cam speeds are presented,an important injection characteristic for EIP system calibration.

  15. Investigating powerful jets in radio-loud Narrow Line Seyfert 1s

    CERN Document Server

    Orienti, M; Larsson, J; Finke, J; Giroletti, M; Dallacasa, D; Isacsson, T; Hoglund, J Stoby

    2015-01-01

    We report results on multiband observations from radio to gamma-rays of the two radio-loud narrow-line Seyfert 1 (NLSy1) galaxies PKS 2004-447 and J1548+3511. Both sources show a core-jet structure on parsec scale, while they are unresolved at the arcsecond scale. The high core dominance and the high variability brightness temperature make these NLSy1 galaxies good gamma-ray source candidates. Fermi-LAT detected gamma-ray emission only from PKS 2004-447, with a gamma-ray luminosity comparable to that observed in blazars. No gamma-ray emission is observed for J1548+3511. Both sources are variable in X-rays. J1548+3511 shows a hardening of the spectrum during high activity states, while PKS 2004-447 has no spectral variability. A spectral steepening likely related to the soft excess is hinted below 2 keV for J1548+3511, while the X-ray spectra of PKS 2004-447 collected by XMM-Newton in 2012 are described by a single power-law without significant soft excess. No additional absorption above the Galactic column de...

  16. Investigations on burning efficiency and exhaust emission of in-line type emulsified fuel system

    Energy Technology Data Exchange (ETDEWEB)

    Tseng, Y.K. [National Chinyi University of Technology (Taiwan). Dept. of Mechanical Engineering; Cheng, H.C. [Point Environmental Protection Technology Company Limited (Taiwan)

    2011-07-28

    In this research, the burning efficiency as well as exhaust emission of a new water-in-oil emulsified fuel system was studied. This emulsified system contains two core processes, the first one is to mix 97% water with 3% emulsifier by volume, and get the milk-like emulsified liquid, while the second one is to compound the milk-like emulsified liquid with heavy oil then obtain the emulsified fuel. In order to overcome the used demulsification problem during in reserve or in transport, this system was designed as a made and use in-line type. From the results of a series of burning tests, the fuel saving can be 8--15%. Also, from the comparison of decline for the heat value and total energy output of emulsified fuel, one can find that the water as the dispersed phase in the combustion process will lead to a micro-explosion as well as the water gas effect, both can raise the combustion temperature and burning efficiency. By comparing the waste gas emission of different types of emulsified fuel, one can know that, the CO2 emission reduces approximately 14%, and NOx emission reduces above 46%, meaning the reduction of the exhaust gas is truly effective. From the exhaust temperature of tail pipe, the waste heat discharge also may reduce 27%, it is quite advantageous to the global warming as well as earth environmental protection.

  17. Investigations on burning efficiency and exhaust emission of in-line type emulsified fuel system

    Directory of Open Access Journals (Sweden)

    Yen Kuei Tseng, Hsien Chang Cheng

    2011-07-01

    Full Text Available In this research, the burning efficiency as well as exhaust emission of a new water-in-oil emulsified fuel system was studied. This emulsified system contains two core processes, the first one is to mix 97% water with 3% emulsifier by volume, and get the milk-like emulsified liquid, while the second one is to compound the milk-like emulsified liquid with heavy oil then obtain the emulsified fuel. In order to overcome the used demulsification problem during in reserve or in transport, this system was designed as a made and use in-line type. From the results of a series burning tests, the fuel saving can be over 8~15%. Also, from the comparison of decline for the heat value and total energy output of varies emulsified fuel, one can find that the water as the dispersed phase in the combustion process will leading a micro-explosion as well as the water gas effect, both can raise the combustion temperature and burning efficiency. By comparing the waste gas emission of different types of emulsified fuel, one can know that, the CO2 emission reduces approximately 14%, and NOx emission reduces above 46%, that means the reduction of the exhaust gas is truly effectively. From the exhaust temperature of tail pipe, the waste heat discharge also may reduce 27%, it is quite advantageous to the global warming as well as earth environmental protection.

  18. An investigation on hybrid interface using on-line monitoring experiment and finite element analyses

    NARCIS (Netherlands)

    Truong, H.T.X.; Martinez, M.J.; Ochoa, O.O.; Lagoudas, D.C.

    2015-01-01

    In this work, the hybrid interface between metal and thermosetting polymer matrix composite was studied via experimental and numerical investigations. Hybrid laminates, whose constituents are aluminum foil, carbon fabric and epoxy matrix, were manufactured using the vacuum assisted resin transfer mo

  19. The 1997 spectroscopic GEISA databank.

    Science.gov (United States)

    Jacquinet-Husson, N.; Arie, E.; Ballard, J.; Barbe, A.; Bjoraker, G.; Bonnet, B.; Brown, L. R.; Camy-Peyret, C.; Champion, J. P.; Chedin, A.; Chursin, A.; Clerbaux, C.; Duxbury, G.; Flaud, J.-M.; Fourrie, N.; Fayt, A.; Graner, G.; Gamache, R.; Goldman, A.; Golovko, V.; Guelachvili, G.; Hartmann, J. M.; Hilico, J. C.; Hillman, J.; Lefevre, G.; Lellouch, E.; Mikhailenko, S. N.; Naumenko, O. V.; Nemtchinov, V.; Newnham, D. A.; Nikitin, A.; Orphal, J.; Perrin, A.; Reuter, D. C.; Rinsland, C. P.; Rosenmann, L.; Rothman, L. S.; Scott, N. A.; Selby, J.; Sinitsa, L. N.; Sirota, J. M.; Smith, A. M.; Smith, K. M.; Tyuterev, V. G.; Tipping, R. H.; Urban, S.; Varanasi, P.; Weber, M.

    1999-05-01

    The current version GEISA-97 of the computer-accessible database system GEISA (Gestion et Etude des Informations Spectroscopiques Atmospheriques: Management and Study of Atmospheric Spectroscopic Information) is described. This catalogue contains 1,346,266 entries. These are the spectroscopic parameters required to describe adequately the individual spectral lines belonging to 42 molecules (96 isotopic species) and located between 0 and 22656 cm-1. The featured molecules are of interest in studies of the terrestrial as well as the other planetary atmospheres, especially those of the giant planets. GEISA-97 contains also a catalog of absorption cross-sections of molecules such as chlorofluorocarbons which exhibit unresolvable spectra. The modifications and improvements made to the earlier edition (GEISA-92) and the data management software are described.

  20. Investigation of cytotoxic activity on human cancer cell lines of arborinine and furanoacridones isolated from Ruta graveolens.

    Science.gov (United States)

    Réthy, Borbála; Zupkó, István; Minorics, Renáta; Hohmann, Judit; Ocsovszki, Imre; Falkay, George

    2007-01-01

    The cytotoxic effects of a series of furanoacridones isolated from Ruta graveolens L. (Rutaceae) and of two further acridone alkaloids (arborinine and evoxanthine) were investigated by means of the MTT assay, using the human cell lines HeLa, MCF7 and A431. Arborinine proved best in inhibiting the proliferation of all three cell lines. The cytotoxic potency of the furacridone alkaloids was a function of their lipid solubility, which was determined by means of PAMPA. The capacity of the most effective furanoacridones to induce apoptosis was demonstrated by flow cytometric cell cycle analysis and by staining with ethidium bromide and acridine orange. This finding was reinforced by determining the apoptosis-regulating factors Bcl-2 and Bax, which were revealed by means of RT-PCR to change dose-dependently. The data presented here indicate that naturally occurring furanoacridones can be regarded as excellent starting structures for the potential development of new anticancer agents.

  1. Investigating the nature of the Fried Egg nebula: CO mm-line and optical spectroscopy of IRAS 17163-3907

    CERN Document Server

    Wallström, Sofia H J; Lagadec, E; Black, J H; Oudmaijer, R D; Justtanont, K; van Winckel, H; Zijlstra, A A

    2015-01-01

    Through CO mm-line and optical spectroscopy, we investigate the properties of the Fried Egg nebula IRAS 17163-3907, which has recently been proposed to be one of the rare members of the yellow hypergiant class. The CO J=2-1 and J=3-2 emission arises from a region within 20" of the star and is clearly associated with the circumstellar material. The CO lines show a multi-component asymmetrical profile, and an unexpected velocity gradient is resolved in the east-west direction, suggesting a bipolar outflow. This is in contrast with the apparent symmetry of the dust envelope as observed in the infrared. The optical spectrum of IRAS 17163-3907 between 5100 and 9000 {\\AA} was compared with that of the archetypal yellow hypergiant IRC+10420 and was found to be very similar. These results build on previous evidence that IRAS 17163-3907 is a yellow hypergiant.

  2. Spectroscopic properties of trivalent praseodymium in barium yttrium fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Di Bartolo, B. E-mail: dibartob@bc.edurinodiba@attbi.com; Bowlby, B.E

    2003-05-01

    We have conducted a spectroscopic investigation of Pr{sup 3+} in barium yttrium fluoride (BaY{sub 2}O{sub 8}). Two doping concentrations were used: BaY{sub 2}F{sub 8}:Pr{sup 3+} (0.3%) and BaY{sub 2}F{sub 8}:Pr{sup 3+} (1%). The measurements included absorption, luminescence under continuous and pulsed excitations, and thermal effects on some sharp lines. The experimental results were used to characterize this system.

  3. Investigation of the RF-imposition method for the unsanctioned information retrieval from a telephone line

    Directory of Open Access Journals (Sweden)

    Юрий Владимирович Лыков

    2015-07-01

    Full Text Available Presented in the paper Investigations are focused on special aspects connected with selection of the carrier frequency values for realization of the RF-imposition method. For this method a possibility of the information leakage from various modern models of telephones is estimated too. It is also analyzed an efficiency of means for blocking of the information leakage by the RF-imposition method and an influence of such means on the speech signal quality during a telephone conversation

  4. Investigation into the interaction of losartan with human serum albumin and glycated human serum albumin by spectroscopic and molecular dynamics simulation techniques: A comparison study.

    Science.gov (United States)

    Moeinpour, Farid; Mohseni-Shahri, Fatemeh S; Malaekeh-Nikouei, Bizhan; Nassirli, Hooriyeh

    2016-09-25

    The interaction between losartan and human serum albumin (HSA), as well as its glycated form (gHSA) was studied by multiple spectroscopic techniques and molecular dynamics simulation under physiological conditions. The binding information, including the binding constants, effective quenching constant and number of binding sites showed that the binding partiality of losartan to HSA was higher than to gHSA. The findings of three-dimensional fluorescence spectra demonstrated that the binding of losartan to HSA and gHSA would alter the protein conformation. The distances between Trp residue and the binding sites of the drug were evaluated on the basis of the Förster theory, and it was indicated that non-radiative energy transfer from HSA and gHSA to the losartan happened with a high possibility. According to molecular dynamics simulation, the protein secondary and tertiary structure changes were compared in HSA and gHSA for clarifying the obtained results.

  5. Synthesis, crystal structure investigation, spectroscopic characterizations and DFT computations on a novel 1-(2-chloro-4-phenylquinolin-3-yl)ethanone