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Sample records for electron-nuclear double-resonance study

  1. Study of γ-irradiated lithographic polymers by electron spin resonance and electron nuclear double resonance

    International Nuclear Information System (INIS)

    Schlick, S.; Kevan, L.

    1982-01-01

    The room temperature gamma irradiation degradation of the lithographic polymers, poly(methylmethacrylate) (PMMA), poly(methyl-α-chloroacrylate) (PMCA), poly(methyl-α-fluoroacrylate) (PMFA), and poly(methylacrylonitrile) (PMCN), have been studied by electron spin resonance and electron nuclear double resonance (ENDOR) to assess their molecular degradation processes of relevance to electron beam lithography. Two classes of radicals are found, chain radicals and chain scission radicals. PMMA and PMCA mainly form chain scission radicals consistent with degradation while for PMCN the resolution is poorer, and this is only probable. PMFA forms mainly chain radicals consistent with predominant crosslinking. The total radical yield is greatest in PMCA and PMCN. ENDOR is used to assess the compactness of the radiation degradation region for PMMA and PMCA and hence the potential resolution of the resist; this appears to be about the same for these methacrylate polymers

  2. Electron paramagnetic resonance and electron-nuclear double-resonance study of Ti sup 3 sup + centres in KTiOPO sub 4

    CERN Document Server

    Setzler, S D; Fernelius, N C; Scripsick, M P; Edwards, G J; Halliburton, L E

    2003-01-01

    Electron paramagnetic resonance and electron-nuclear double resonance have been used to characterize four Ti sup 3 sup + centres in undoped crystals of potassium titanyl phosphate (KTiOPO sub 4 or KTP). These 3d sup 1 defects (S = 1/2) are produced by ionizing radiation (either 60 kV x-rays or 355 nm photons from a tripled Nd:YAG laser), and form when the regular Ti sup 4 sup + ions in the crystal trap an electron. Two of these trapped-electron centres are only observed in hydrothermally grown KTP and the other two are dominant in flux-grown KTP. Both of the Ti sup 3 sup + centres in hydrothermally grown crystals have a neighbouring proton (i.e. an OH sup - molecule). In the flux-grown crystals, one of the Ti sup 3 sup + centres is adjacent to an oxygen vacancy and the other centre is tentatively attributed to a self-trapped electron (i.e. a Ti sup 3 sup + centre with no stabilizing entity nearby). The g matrix and phosphorus hyperfine matrices are determined for all four Ti sup 3 sup + centres, and the proto...

  3. Electron paramagnetic resonance and electron-nuclear double resonance study of the neutral copper acceptor in ZnGeP sub 2 crystals

    CERN Document Server

    Stevens, K T; Setzler, S D; Schünemann, P G; Pollak, T M

    2003-01-01

    Electron paramagnetic resonance (EPR) and electron-nuclear double resonance have been used to characterize the neutral copper acceptor in ZnGeP sub 2 crystals. The copper substitutes for zinc and behaves as a conventional acceptor (i.e. the 3d electrons do not play a dominant role). Because of a high degree of compensation from native donors, the copper acceptors in our samples were initially in the nonparamagnetic singly ionized state (Cu sub Z sub n sup -). The paramagnetic neutral state (Cu sub Z sub n sup 0) was observed when the crystals were exposed to 632.8 nm or 1064 nm laser light while being held at a temperature below 50 K. The g matrix of the neutral copper acceptor is axial g sub p sub a sub r = 2.049 and g sub p sub e sub r sub p = 2.030), with the unique principal direction parallel to the tetragonal c axis of the crystal. The hyperfine and nuclear quadrupole matrices also exhibit c-axis symmetry (A sub p sub a sub r = 87.6 MHz, A sub p sub e sub r sub p = 34.8 MHz and P = 0.87 MHz for sup 6 su...

  4. Electron paramagnetic resonance and electron-nuclear double-resonance study of Ti{sup 3+} centres in KTiOPO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Setzler, S D [BAE Systems, Nashua, NH 03061 (United States); Stevens, K T [Northrop Grumman, Space Technology, Synoptics, Charlotte, NC 28273 (United States); Fernelius, N C [Air Force Research Laboratory, Materials and Manufacturing Directorate, AFRL/MLPSO, Wright-Patterson AFB, OH 45433 (United States); Scripsick, M P [Nova Phase, Newton, NJ 07860 (United States); Edwards, G J [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Halliburton, L E [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States)

    2003-06-18

    Electron paramagnetic resonance and electron-nuclear double resonance have been used to characterize four Ti{sup 3+} centres in undoped crystals of potassium titanyl phosphate (KTiOPO{sub 4} or KTP). These 3d{sup 1} defects (S = 1/2) are produced by ionizing radiation (either 60 kV x-rays or 355 nm photons from a tripled Nd:YAG laser), and form when the regular Ti{sup 4+} ions in the crystal trap an electron. Two of these trapped-electron centres are only observed in hydrothermally grown KTP and the other two are dominant in flux-grown KTP. Both of the Ti{sup 3+} centres in hydrothermally grown crystals have a neighbouring proton (i.e. an OH{sup -} molecule). In the flux-grown crystals, one of the Ti{sup 3+} centres is adjacent to an oxygen vacancy and the other centre is tentatively attributed to a self-trapped electron (i.e. a Ti{sup 3+} centre with no stabilizing entity nearby). The g matrix and phosphorus hyperfine matrices are determined for all four Ti{sup 3+} centres, and the proton hyperfine matrix is determined for the two centres associated with OH{sup -} ions. These Ti{sup 3+} centres contribute to the formation of the grey tracks often observed in KTP crystals used to generate the second harmonic of high-power, near-infrared lasers.

  5. Contribution to the study of molecular movements in cyclohexane by electron spin resonance and electron-nuclear double resonance using a radical probe; Contribution a l'etude des mouvements moleculaires dans le cyclohexane par resonance paramagnetique electronique et double resonance electronique-nucleaire a l'aide d'une sonde radicalaire

    Energy Technology Data Exchange (ETDEWEB)

    Volino, F [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    Solutions of stable free radicals of the nitroxide type have been studied as a function of temperature. In the plastic or globular state, the cyclohexane molecules have rapid rotational and diffusional movements. They transmit this movement to dissolved free radicals. Conversely, measurements by electron spin resonance of the absolute movement of the radicals, and by electron nuclear double resonance of their movement relative to the cyclohexane molecules give very precise methods for local analyses of the movement present in the cyclohexane matrix. The principle of these techniques makes up the 'radical probe method'. (author) [French] Des solutions de radicaux libres stables, du type nitroxyde dans le cyclohexane ont ete etudiees, en fonction de la temperature. Les molecules de cyclohexane, dans l'etat plastique ou globulaire, sont animees de mouvements rapides de rotation sur elles-memes et de diffusion. Elles transmettent leur mobilite aux radicaux libres dissous. Reciproquement, la mesure du mouvement absolu des radicaux, a l'aide de la resonance paramagnetique electronique, et celle du mouvement relatif des radicaux et des molecules de cyclohexane par double resonance electronique-nucleaire, constituent des methodes tres precises pour analyser localement les mouvements presents dans la matrice de cyclohexane. Ce principe et ces techniques constituent la 'methode de la sonde radicalaire'. (auteur)

  6. Contribution to the study of molecular movements in cyclohexane by electron spin resonance and electron-nuclear double resonance using a radical probe; Contribution a l'etude des mouvements moleculaires dans le cyclohexane par resonance paramagnetique electronique et double resonance electronique-nucleaire a l'aide d'une sonde radicalaire

    Energy Technology Data Exchange (ETDEWEB)

    Volino, F. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    Solutions of stable free radicals of the nitroxide type have been studied as a function of temperature. In the plastic or globular state, the cyclohexane molecules have rapid rotational and diffusional movements. They transmit this movement to dissolved free radicals. Conversely, measurements by electron spin resonance of the absolute movement of the radicals, and by electron nuclear double resonance of their movement relative to the cyclohexane molecules give very precise methods for local analyses of the movement present in the cyclohexane matrix. The principle of these techniques makes up the 'radical probe method'. (author) [French] Des solutions de radicaux libres stables, du type nitroxyde dans le cyclohexane ont ete etudiees, en fonction de la temperature. Les molecules de cyclohexane, dans l'etat plastique ou globulaire, sont animees de mouvements rapides de rotation sur elles-memes et de diffusion. Elles transmettent leur mobilite aux radicaux libres dissous. Reciproquement, la mesure du mouvement absolu des radicaux, a l'aide de la resonance paramagnetique electronique, et celle du mouvement relatif des radicaux et des molecules de cyclohexane par double resonance electronique-nucleaire, constituent des methodes tres precises pour analyser localement les mouvements presents dans la matrice de cyclohexane. Ce principe et ces techniques constituent la 'methode de la sonde radicalaire'. (auteur)

  7. Free radical formation in single crystals of 9-methyladenine X-irradiated at 10 K. An electron paramagnetic resonance and electron nuclear double resonance study

    International Nuclear Information System (INIS)

    Hole, E.O.; Sagstuen, E.; Nelson, W.H.

    1995-01-01

    Single crystals of 9-methyladenine were X-irradiated at 10 K and at 65 K and were studied using K-band EPR, ENDOR and field-swept ENDOR (FSE) techniques in the temperature range 10 K to 290 K. Three major radicals are stabilized in 9-methyladenine at 10 K. These are: MA1, the adenine anion, probably protonated at N3; MA2, the species formed by net hydrogen abstraction from the 9-methyl group; and MA3, the radical formed by net hydrogen addition to C8 of the adenine moiety. Radical MA1 decayed at about 80 K, possibly into the C2 H adduct (MA4). The other two species (MA2, MA3) were stable at room temperature. A fifth radical species was clearly present in the EPR spectra at 10 K but was not detectable by ENDOR. This species, which decayed above 200 K (possibly into MA3), remains unidentified. The radical population at room temperature is as described by previous authors. The mechanisms for radical formation in 9-methyladenine are discussed in light of the hydrogen bonding scheme and molecular stacking interactions. 32 refs., 4 figs., 2 tabs

  8. Why Nature Uses Radical SAM Enzymes so Widely: Electron Nuclear Double Resonance Studies of Lysine 2,3-Aminomutase Show the 5'-dAdo• "Free Radical" Is Never Free.

    Science.gov (United States)

    Horitani, Masaki; Byer, Amanda S; Shisler, Krista A; Chandra, Tilak; Broderick, Joan B; Hoffman, Brian M

    2015-06-10

    Lysine 2,3-aminomutase (LAM) is a radical S-adenosyl-L-methionine (SAM) enzyme and, like other members of this superfamily, LAM utilizes radical-generating machinery comprising SAM anchored to the unique Fe of a [4Fe-4S] cluster via a classical five-membered N,O chelate ring. Catalysis is initiated by reductive cleavage of the SAM S-C5' bond, which creates the highly reactive 5'-deoxyadenosyl radical (5'-dAdo•), the same radical generated by homolytic Co-C bond cleavage in B12 radical enzymes. The SAM surrogate S-3',4'-anhydroadenosyl-L-methionine (anSAM) can replace SAM as a cofactor in the isomerization of L-α-lysine to L-β-lysine by LAM, via the stable allylic anhydroadenosyl radical (anAdo•). Here electron nuclear double resonance (ENDOR) spectroscopy of the anAdo• radical in the presence of (13)C, (2)H, and (15)N-labeled lysine completes the picture of how the active site of LAM from Clostridium subterminale SB4 "tames" the 5'-dAdo• radical, preventing it from carrying out harmful side reactions: this "free radical" in LAM is never free. The low steric demands of the radical-generating [4Fe-4S]/SAM construct allow the substrate target to bind adjacent to the S-C5' bond, thereby enabling the 5'-dAdo• radical created by cleavage of this bond to react with its partners by undergoing small motions, ∼0.6 Å toward the target and ∼1.5 Å overall, that are controlled by tight van der Waals contact with its partners. We suggest that the accessibility to substrate and ready control of the reactive C5' radical, with "van der Waals control" of small motions throughout the catalytic cycle, is common within the radical SAM enzyme superfamily and is a major reason why these enzymes are the preferred means of initiating radical reactions in nature.

  9. Why Nature Uses Radical SAM Enzymes so Widely: Electron Nuclear Double Resonance Studies of Lysine 2,3-Aminomutase Show the 5′-dAdo• “Free Radical” Is Never Free

    Science.gov (United States)

    Horitani, Masaki; Byer, Amanda S.; Shisler, Krista A.; Chandra, Tilak; Broderick, Joan B.; Hoffman, Brian M.

    2015-01-01

    Lysine 2,3-aminomutase (LAM) is a radical S-adenosyl-L-methionine (SAM) enzyme and, like other members of this superfamily, LAM utilizes radical-generating machinery comprising SAM anchored to the unique Fe of a [4Fe-4S] cluster via a classical five-membered N,O chelate ring. Catalysis is initiated by reductive cleavage of the SAM S–C5′ bond, which creates the highly reactive 5′-deoxyadenosyl radical (5′-dAdo•), the same radical generated by homolytic Co–C bond cleavage in B12 radical enzymes. The SAM surrogate S-3′,4′-anhydroadenosyl-L-methionine (anSAM) can replace SAM as a cofactor in the isomerization of L-α-lysine to L-β-lysine by LAM, via the stable allylic anhydroadenosyl radical (anAdo•). Here electron nuclear double resonance (ENDOR) spectroscopy of the anAdo• radical in the presence of 13C, 2H, and 15N-labeled lysine completes the picture of how the active site of LAM from Clostridium subterminale SB4 “tames” the 5′-dAdo• radical, preventing it from carrying out harmful side reactions: this “free radical” in LAM is never free. The low steric demands of the radical-generating [4Fe-4S]/SAM construct allow the substrate target to bind adjacent to the S–C5′ bond, thereby enabling the 5′-dAdo• radical created by cleavage of this bond to react with its partners by undergoing small motions, ~0.6 Å toward the target and ~1.5 Å overall, that are controlled by tight van der Waals contact with its partners. We suggest that the accessibility to substrate and ready control of the reactive C5′ radical, with “van der Waals control” of small motions throughout the catalytic cycle, is common within the radical SAM enzyme superfamily and is a major reason why these enzymes are the preferred means of initiating radical reactions in nature. PMID:25923449

  10. Electron spin resonance (ESR), electron nuclear double resonance (ENDOR) and general triple resonance of irradiated biocarbonates

    International Nuclear Information System (INIS)

    Schramm, D.U.; Rossi, A.M.

    1996-01-01

    Several irradiated bicarbonates were studied by magnetic resonance techniques. Seven paramagnetic species, attributed to CO 2 - , SO 2 - and SO 3 - were identified. Comparison between radiation induced defects in bioaragonites and aragonite single-crystals show that isotropic and orthorhombic CO 2 - centers with broad line spectra are not produced in the latter samples. Vibrational and rotational properties of isotropic CO 2 - centers were studied from low temperature Q-band spectras. Vibrational frequency is determined from the 13 CO 2 - hyperfine spectrum and yielded ν 1.54 x 10 13 s -1 . The correlation time for isotropic CO 2 - , τc) = 1.2 x 10 -11 s (T = 300 K0, is typical of radicals rotating in liquids. ENDOR and General Triple spectroscopy show that orthorhombic CO 2 - centres are surrounded by water molecules located in the second nearest CO 2 2- sites at 5.14, 5.35 and 6.02 A. Water molecules replacing carbonates or as liquid inclusion of growth solution in local crystal imperfections may be responsible for the variety of orthorhombic and isotropic CO 2 - species, respectively. (author)

  11. Some double resonance and multiple quantum NMR studies in solids

    Energy Technology Data Exchange (ETDEWEB)

    Wemmer, D.E.

    1978-08-01

    The first section of this work presents the theory and experimental applications to analysis of molecular motion of chemical shielding lineshapes obtained with high resolution double resonance NMR techniques. Analysis of /sup 13/C powder lineshapes in hexamethylbenzene (HMB) and decamethylferrocene (DMFe) show that these molecules reorient in a jumping manner about the symmetry axis. Analysis of proton chemical shielding lineshapes of residual protons in heavy ice (D/sub 2/O) show that protons are exchanged among the tetrahedral positions of neighboring oxygen atoms, consistent with motion expected from defect migration. The second section describes the application of Fourier Transform Double Quantum NMR to measurement of chemical shielding of deuterium in powder samples. Studies of partially deuterated benzene and ferrocene give equal shielding anisotropies, ..delta..sigma = -6.5 ppM. Theoretical predictions and experimental measurements of dipolar couplings between deuterons using FTDQ NMR are presented. Crystals of BaClO/sub 3/.D/sub 2/O, ..cap alpha..,..beta.. d-2 HMB and ..cap alpha..,..beta..,..gamma.. d-3 HMB were studied, as were powders of d-2 HMB and anisic acid. The third section discusses general multiple quantum spectroscopy in dipolar coupled spin systems. Theoretical description is made for creation and detection of coherences between states without quantum number selection rules ..delta..m = +-1. Descriptions of techniques for partial selectivity of order in preparation and detection of multiple quantum coherences are made. The effects on selectivity and resolution of echo pulses during multiple quantum experiments are discussed. Experimental observation of coherences up to order 6 have been made in a sample of benzene dissolved in a liquid crystal. Experimental verifications of order selection and echo generation have been made.

  12. Some double resonance and multiple quantum NMR studies in solids

    International Nuclear Information System (INIS)

    Wemmer, D.E.

    1978-08-01

    The first section of this work presents the theory and experimental applications to analysis of molecular motion of chemical shielding lineshapes obtained with high resolution double resonance NMR techniques. Analysis of 13 C powder lineshapes in hexamethylbenzene (HMB) and decamethylferrocene (DMFe) show that these molecules reorient in a jumping manner about the symmetry axis. Analysis of proton chemical shielding lineshapes of residual protons in heavy ice (D 2 O) show that protons are exchanged among the tetrahedral positions of neighboring oxygen atoms, consistent with motion expected from defect migration. The second section describes the application of Fourier Transform Double Quantum NMR to measurement of chemical shielding of deuterium in powder samples. Studies of partially deuterated benzene and ferrocene give equal shielding anisotropies, Δsigma = -6.5 ppM. Theoretical predictions and experimental measurements of dipolar couplings between deuterons using FTDQ NMR are presented. Crystals of BaClO 3 .D 2 O, α,β d-2 HMB and α,β,γ d-3 HMB were studied, as were powders of d-2 HMB and anisic acid. The third section discusses general multiple quantum spectroscopy in dipolar coupled spin systems. Theoretical description is made for creation and detection of coherences between states without quantum number selection rules Δm = +-1. Descriptions of techniques for partial selectivity of order in preparation and detection of multiple quantum coherences are made. The effects on selectivity and resolution of echo pulses during multiple quantum experiments are discussed. Experimental observation of coherences up to order 6 have been made in a sample of benzene dissolved in a liquid crystal. Experimental verifications of order selection and echo generation have been made

  13. Aluminum and gallium nuclei as microscopic probes for pulsed electron-nuclear double resonance diagnostics of electric-field gradient and spin density in garnet ceramics doped with paramagnetic ions

    Science.gov (United States)

    Uspenskaya, Yu. A.; Mamin, G. V.; Babunts, R. A.; Badalyan, A. G.; Edinach, E. V.; Asatryan, H. R.; Romanov, N. G.; Orlinskii, S. B.; Khanin, V. M.; Wieczorek, H.; Ronda, C.; Baranov, P. G.

    2018-03-01

    The presence of aluminum and gallium isotopes with large nuclear magnetic and quadrupole moments in the nearest environment of impurity ions Mn2+ and Ce3+ in garnets made it possible to use hyperfine and quadrupole interactions with these ions to determine the spatial distribution of the unpaired electron and the gradient of the electric field at the sites of aluminum and gallium in the garnet lattice. High-frequency (94 GHz) electron spin echo detected electron paramagnetic resonance and electron-nuclear double resonance measurements have been performed. Large difference in the electric field gradient and quadrupole splitting at octahedral and tetrahedral sites allowed identifying the positions of aluminum and gallium ions in the garnet lattice and proving that gallium first fills tetrahedral positions in mixed aluminum-gallium garnets. This should be taken into account in the development of garnet-based scintillators and lasers. It is shown that the electric field gradient at aluminum nuclei near Mn2+ possessing an excess negative charge in the garnet lattice is ca. 2.5 times larger than on aluminum nuclei near Ce3+.

  14. Rotational-echo Double-resonance in Complex Biopolymers: a Study of Nephila Clavipes Dragline Silk

    International Nuclear Information System (INIS)

    Michal, Carl A.; Jelinski, Lynn W.

    1998-01-01

    Rotational-Echo Double-Resonance (REDOR) NMR on strategically 13C and 15N labeled samples is used to study the conformation of the LGXQ (X = S, G, or N) motif in the major ampullate gland dragline silk from the spider Nephila clavipes. A method is described for calculating REDOR dephasing curves suitable for background subtractions, using probability distributions of nitrogen atoms surrounding a given carbon site, which are developed from coordinates in the Brookhaven Protein Data Bank. The validity of the method is established by comparison to dephasings observed from natural abundance 13C peaks for G and A. Straightforward fitting of universal REDOR dephasing curves to the background corrected peaks of interest provide results which are not self-consistent, and a more sophisticated analysis is developed which better accounts for 15N labels which have scrambled from the intended positions. While there is likely some heterogeneity in the structures formed by the LGXQ sequences, the data indicate that they all form compact turn-like structures

  15. Pulse Double-Resonance EPR Techniques for the Study of Metallobiomolecules.

    Science.gov (United States)

    Cox, Nicholas; Nalepa, Anna; Pandelia, Maria-Eirini; Lubitz, Wolfgang; Savitsky, Anton

    2015-01-01

    Electron paramagnetic resonance (EPR) spectroscopy exploits an intrinsic property of matter, namely the electron spin and its related magnetic moment. This can be oriented in a magnetic field and thus, in the classical limit, acts like a little bar magnet. Its moment will align either parallel or antiparallel to the field, giving rise to different energies (termed Zeeman splitting). Transitions between these two quantized states can be driven by incident microwave frequency radiation, analogous to NMR experiments, where radiofrequency radiation is used. However, the electron Zeeman interaction alone provides only limited information. Instead, much of the usefulness of EPR is derived from the fact that the electron spin also interacts with its local magnetic environment and thus can be used to probe structure via detection of nearby spins, e.g., NMR-active magnetic nuclei and/or other electron spin(s). The latter is exploited in spin labeling techniques, an exciting new area in the development of noncrystallographic protein structure determination. Although these interactions are often smaller than the linewidth of the EPR experiment, sophisticated pulse EPR methods allow their detection. A number of such techniques are well established today and can be broadly described as double-resonance methods, in which the electron spin is used as a reporter. Below we give a brief description of pulse EPR methods, particularly their implementation at higher magnetic fields, and how to best exploit them for studying metallobiomolecules. © 2015 Elsevier Inc. All rights reserved.

  16. Liquid-Liquid Phase Separation in Model Nuclear Waste Glasses: A Solid-State Double-Resonance NMR Study

    Energy Technology Data Exchange (ETDEWEB)

    Martineau, Ch.; Michaelis, V.K.; Kroeker, S. [Univ Manitoba, Dept Chem, Winnipeg, MB R3T 2N2 (Canada); Schuller, S. [CEA Valrho Marcoule, LDMC, SECM, DTCD, DEN, F-30207 Bagnols Sur Ceze (France)

    2010-07-01

    Double-resonance nuclear magnetic resonance (NMR) techniques are used in addition to single-resonance NMR experiments to probe the degree of mixing between network-forming cations Si and B, along with the modifier cations Cs{sup +} and Na{sup +} in two molybdenum-bearing model nuclear waste glasses. The double-resonance experiments involving {sup 29}Si in natural abundance are made possible by the implementation of a CPMG pulse-train during the acquisition period of the usual REDOR experiments. For the glass with lower Mo content, the NMR results show a high degree of Si-B mixing, as well as an homogeneous distribution of the cations within the borosilicate network, characteristic of a non-phase-separated glass. For the higher-Mo glass, a decrease of B-Si(Q{sup 4}) mixing is observed, indicating phase separation. {sup 23}Na and {sup 133}Cs NMR results show that although the Cs{sup +} cations, which do not seem to be influenced by the molybdenum content, are spread within the borate network, there is a clustering of the Na{sup +} cations, very likely around the molybdate units. The segregation of a Mo-rich region with Na{sup +} cations appears to shift the bulk borosilicate glass composition toward the metastable liquid liquid immiscibility region and induce additional phase separation. Although no crystallization is observed in the present case, this liquid liquid phase separation is likely to be the first stage of crystallization that can occur at higher Mo loadings or be driven by heat treatment. From this study emerges a consistent picture of the nature and extent of such phase separation phenomena in Mo-bearing glasses, and demonstrates the potential of double-resonance NMR methods for the investigation of phase separation in amorphous materials. (authors)

  17. A study of relaxation mechanisms in the A{sup 2}{Sigma}{sup +} state of nitric oxide by time resolved double resonant polarization spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Stampanoni-Panariello, A; Bombach, R; Hemmerling, B; Hubschmid, W [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Double resonant polarization labeling spectroscopy is applied to detect nitric oxide in flames and to characterize rotational energy transfer and orientation changing collisions in its first excited electronic state. (author) 4 figs., 3 refs.

  18. Electric-dipole moment of CaF by molecular-beam, laser-rf, double-resonance study of Stark splittings

    International Nuclear Information System (INIS)

    Childs, W.J.; Goodman, L.S.; Nielsen, U.; Pfeufer, V.

    1984-01-01

    The electronic structure of diatomic molecules is much more complex for open-shell sytems (radicals) than for the normal closed-shell systems, and the development of an adequate theoretical understanding will require a substantial upgrading of experimental knowledge in both quality and quantity. The alkaline-earth monohalide family of radicals, with only a single electron outside closed-shell cores, would appear to be a logical starting point for such studies, and there has been a great increase in work in this area in the last few years in spite of the special difficulties of working with free radicals. As the work of measuring the vibrational and rotational structure of the electronic states has become more complete, attention has turned to study of the much weaker spin-rotation and hyperfine interactions. Within the last three years, these interactions have been studied systematically at high precision in the calcium monohalide family with the molecular-beam, laser-rf double-resonance technique. The same method has now been modified and extended to make possible measurement of the electric-dipole moments of these molecules through observation of the Stark splittings of radiofrequency transitions. It is hoped that when considered together, the several types of data will make it possible to understand the ground-state electronic wave functions of these molecules at least qualitatively. 2 figures

  19. Multinuclear solid-state high-resolution and C-13 -{Al-27} double-resonance magic-angle spinning NMR studies on aluminum alkoxides

    NARCIS (Netherlands)

    Abraham, A.; Prins, R.; Bokhoven, J.A. van; Eck, E.R.H. van; Kentgens, A.P.M.

    2006-01-01

    A combination of Al-27 magic-angle spinning (MAS)/multiple quantum (MQ)-MAS, C-13-H-1 CPMAS, and C-13-{Al-27} transfer of population in double-resonance (TRAPDOR) nuclear magnetic resonance (NMR) were used for the structural elucidation of the aluminum alkoxides aluminum ethoxide, aluminum

  20. Electron spin resonance and E.N.D.O.R. double resonance study of free radicals produced by gamma irradiation of imidazole single crystals; Etude par resonance paramagnetique electronique et double resonance E.N.D.O.R. des radicaux libres crees par irradiation gamma de monocristaux d'imidazole

    Energy Technology Data Exchange (ETDEWEB)

    Lamotte, B [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1970-07-01

    Gamma irradiation of imidazole single crystals at 300 deg. K gives two radicals. Identification and detailed studies of their electronic and geometric structure have been made by ESR and ENDOR techniques. A study of the hydrogen bonded protons hyperfine tensor is made and let us conclude to the inexistence of movement and tunneling of these protons. The principal low temperature radical, produced by gamma irradiation at 77 deg. K has been also studied by ESR and a model has been proposed. (author) [French] L'irradiation gamma de monocristaux d'imidazole a 300 deg. K conduit a deux radicaux dont l'identification et l'etude detaillee des structures electroniques et geometriques ont ete obtenues par la resonance paramagnetique electronique (RPE) et la double resonance ENDOR. En particulier l'examen des protons de la liaison hydrogene permet de conclure, pour ceux-ci, a l'inexistence de tout mouvement par effet tunnel. De plus, l'analyse des spectres de RPE du radical principal cree par irradiation gamma de l'imidazole a 77 deg. K nous a permis de proposer un modele pour ce radical. (auteur)

  1. Double resonance Raman effects in InN nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Domenech-Amador, N.; Cusco, R.; Artus, L. [Institut Jaume Almera, Consell Superior d' Investigacions Cientifiques (CSIC), Lluis Sole i Sabaris s.n., Barcelona, Catalonia (Spain); Calarco, R. [Institute of Bio- and Nanosystems, Research Center Juelich GmbH, Juelich (Germany); Paul-Drude-Institut fuer Festkoerperelektronik, Berlin (Germany); Yamaguchi, T.; Nanishi, Y. [Faculty of Science and Engineering, Ritsumeikan University, Noji-Higashi, Kusatsu, Shiga 525-8577 (Japan)

    2012-04-15

    We study the excitation wavelength dependence of the Raman spectra of InN nanowires. The E{sub 1}(LO) phonon mode, which is detected in backscattering configuration because of light entering through lateral faces, exhibits an upward frequency shift that can be explained by Martin's double resonance. The E{sub 1} (LO)/E{sub 2}{sup h} intensity ratio increases with the excitation wavelength more rapidly than the A{sub 1}(LO)/E{sub 2}{sup h} ratio measured in InN thin films. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Nature of isomerism of solid isothiourea salts, inhibitors of nitric oxide synthases, as studied by 1H-14N nuclear quadrupole double resonance, X-ray, and density functional theory/quantum theory of atoms in molecules.

    Science.gov (United States)

    Latosińska, J N; Latosińska, M; Seliger, J; Žagar, V; Maurin, J K; Kazimierczuk, Z

    2012-02-09

    Isothioureas, inhibitors of nitric oxide synthases, have been studied experimentally in solid state by nuclear quadrupole double resonance (NQDR) and X-ray methods and theoretically by the quantum theory of atoms in molecules/density functional theory. Resonance frequencies on (14)N have been detected and assigned to particular nitrogen sites in each molecule. The crystal packings of (S)-3,4-dichlorobenzyl-N-methylisothiouronium chloride with the disordered chlorine positions in benzene ring and (S)-butyloisothiouronium bromide have been resolved in X-ray diffraction studies. (14)N NQDR spectra have been found good indicators of isomer type and strength of intra- or intermolecular N-H···X (X = Cl, Br) interactions. From among all salts studied, only for (S)-2,3,4,5,6-pentabromobenzylisothiouronium chloride are both nitrogen sites equivalent, which has been explained by the slow exchange. This unique structural feature can be a key factor in the high biological activity of (S)-2,3,4,5,6-pentabromobenzylisothiouronium salts.

  3. Electron spin resonance and E.N.D.O.R. double resonance study of free radicals produced by gamma irradiation of imidazole single crystals

    International Nuclear Information System (INIS)

    Lamotte, B.

    1970-01-01

    Gamma irradiation of imidazole single crystals at 300 deg. K gives two radicals. Identification and detailed studies of their electronic and geometric structure have been made by ESR and ENDOR techniques. A study of the hydrogen bonded protons hyperfine tensor is made and let us conclude to the inexistence of movement and tunneling of these protons. The principal low temperature radical, produced by gamma irradiation at 77 deg. K has been also studied by ESR and a model has been proposed. (author) [fr

  4. Microwave-optical double resonance spectroscopy. Final report, February 1, 1971-October 31, 1980

    International Nuclear Information System (INIS)

    Pratt, D.W.

    1982-01-01

    Optical, zero-field and high-field optical detection of magnetic resonance, electron-nuclear double resonance, level anticrossing and cross relaxation, and electron paramagnetic resonance experiments have been performed on a variety of chemical systems in order to further basic knowledge of the structure, reactivity, and response to radiation of molecules in their ground and/or excited electronic states. Systems investigated include organic molecules oriented in low temperature crystals, simple free radicals, transition metal complexes, rare earth hydrides, and hemeproteins in biological enzymes. Many of these systems are of potential importance in a number of applied areas including hydrocarbon-based fuel systems, solar energy devices, laser-initiated photochemical reactions, and free radical mechanisms in chemical carcinogenesis

  5. Microwave-optical double resonance spectroscopy. Progress report, February 1, 1978--January 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, D.W.

    1978-11-01

    Optical, zero-field and high-field optical detection of magnetic resonance, electron-nuclear double resonance, level anticrossing and cross relaxation, and electron paramagnetic resonance experiments have been performed on a variety of chemical systems in order to further basic knowledge of the structure, reactivity, and response to radiation of molecules in their ground and/or excited electronic states. Systems investigated include organic molecules oriented in low temperature crystals, simple free radicals, transition metal complexes, rare earth hydrides, and hemeproteins in biological enzymes. Aside from their intrinsic interest, many of these systems are of potential importance in a number of applied areas including hydrocarbon-based fuel systems, solar energy devices, laser-initiated photochemical reactions, and free radical mechanisms in chemical carcinogenesis.

  6. Microwave-optical double resonance spectroscopy. Progress report, February 1, 1978--January 31, 1979

    International Nuclear Information System (INIS)

    Pratt, D.W.

    1978-01-01

    Optical, zero-field and high-field optical detection of magnetic resonance, electron-nuclear double resonance, level anticrossing and cross relaxation, and electron paramagnetic resonance experiments have been performed on a variety of chemical systems in order to further basic knowledge of the structure, reactivity, and response to radiation of molecules in their ground and/or excited electronic states. Systems investigated include organic molecules oriented in low temperature crystals, simple free radicals, transition metal complexes, rare earth hydrides, and hemeproteins in biological enzymes. Aside from their intrinsic interest, many of these systems are of potential importance in a number of applied areas including hydrocarbon-based fuel systems, solar energy devices, laser-initiated photochemical reactions, and free radical mechanisms in chemical carcinogenesis

  7. Topology of the interactions pattern in pharmaceutically relevant polymorphs of methylxanthines (caffeine, theobromine, and theophiline): combined experimental (¹H-¹⁴N nuclear quadrupole double resonance) and computational (DFT and Hirshfeld-based) study.

    Science.gov (United States)

    Latosińska, Jolanta Natalia; Latosińska, Magdalena; Olejniczak, Grzegorz A; Seliger, Janez; Žagar, Veselko

    2014-09-22

    Three anhydrous methylxanthines: caffeine (1,3,7-trimethylxanthine; 1,3,7-trimethyl-1H-purine-2,6-(3H,7H)-dione) and its two metabolites theophylline (1,3-dimethylxanthine; 1,3-dimethyl-7H-purine-2,6-dione) and theobromine (3,7-dimethyl-xanthine; 3,7-dimethyl-7H-purine-2,6-dione), which reveal multifaceted therapeutic potential, have been studied experimentally in solid state by (1)H-(14)N NMR-NQR (nuclear magnetic resonance-nuclear quadrupole resonance) double resonance (NQDR). For each compound the complete NQR spectrum consisting of 12 lines was recorded. The multiplicity of NQR lines indicates the presence of a stable β form of anhydrous caffeine at 233 K and stable form II of anhydrous theobromine at 213 K. The assignment of signals detected in NQR experiment to particular nitrogen atoms was made on the basis of quantum chemistry calculations performed for monomer, cluster, and solid at the DFT/GGA/BLYP/DPD level. The shifts due to crystal packing interactions were evaluated, and the multiplets detected by NQR were assigned to N(9) in theobromine and N(1) and N(9) in caffeine. The ordering theobromine > theophylline > caffeine site and theophylline theobromine theobromine) to π···π stacking (caffeine). Substantial differences in the intermolecular interactions in stable forms of methylxanthines differing in methylation (site or number) were analyzed within the Hirshfeld surface-based approach. The analysis of local environment of the nitrogen nucleus permitted drawing some conclusions on the nature of the interactions required for effective processes of recognition and binding of a given methylxanthine to A1-A(2A) receptor (target for caffeine in the brain). Although the interactions responsible for linking neighboring methylxanthines molecules in crystals and methylxanthines with targets in the human organism can differ significantly, the knowledge of the topology of interactions provides reliable preliminary information about the nature of this binding.

  8. Efficient 525 nm laser generation in single or double resonant cavity

    Science.gov (United States)

    Liu, Shilong; Han, Zhenhai; Liu, Shikai; Li, Yinhai; Zhou, Zhiyuan; Shi, Baosen

    2018-03-01

    This paper reports the results of a study into highly efficient sum frequency generation from 792 and 1556 nm wavelength light to 525 nm wavelength light using either a single or double resonant ring cavity based on a periodically poled potassium titanyl phosphate crystal (PPKTP). By optimizing the cavity's parameters, the maximum power achieved for the resultant 525 nm laser was 263 and 373 mW for the single and double resonant cavity, respectively. The corresponding quantum conversion efficiencies were 8 and 77% for converting 1556 nm photons to 525 nm photons with the single and double resonant cavity, respectively. The measured intra-cavity single pass conversion efficiency for both configurations was about 5%. The performances of the sum frequency generation in these two configurations was studied and compared in detail. This work will provide guidelines for optimizing the generation of sum frequency generated laser light for a variety of configurations. The high conversion efficiency achieved in this work will help pave the way for frequency up-conversion of non-classical quantum states, such as the squeezed vacuum and single photon states. The proposed green laser source will be used in our future experiments, which includes a plan to generate two-color entangled photon pairs and achieve the frequency down-conversion of single photons carrying orbital angular momentum.

  9. Radiofrequency/infrared double resonance spectroscopy of the HD+ ion

    International Nuclear Information System (INIS)

    Carrington, Alan; McNab, I.R.; Montgomerie, C.A.

    1989-01-01

    We describe a double resonance technique for obtaining radiofrequency spectra of the HD + ion in vibration-rotation levels close to the dissociation limit. Infrared transitions are driven by Doppler tuning an HD + ion beam into resonance with a carbon dioxide infrared laser, and are detected by measuring H + fragment ions produced by electric field dissociation of the upper vibration-rotation level. Radiofrequency transitions between nuclear hyperfine components of the lower vibration-rotation level are then detected through resonant increases in the H + fragment ion current. The high spectroscopic resolution obtained, and the ability to measure magnetic dipole hyperfine transitions, will enable the hyperfine constants to be determined accurately. (author)

  10. Double resonant excitation of the second harmonic of terahertz raditation in dielectricgraphene layered metamaterials

    DEFF Research Database (Denmark)

    Rapoport, Yu; Grimalsky, V.; Lavrinenko, Andrei

    2017-01-01

    to the interfaces, and generation of the p-type second harmonic wave occurs. The original concept is proposed to employ the double resonance arrangement for the effective generation of the second harmonic. The double resonant case can be realized when a high-permittivity dielectric is at the input of the structure...

  11. Switchable coupling for superconducting qubits using double resonance in the presence of crosstalk

    International Nuclear Information System (INIS)

    Ashhab, S.; Nori, Franco

    2007-01-01

    Several methods have been proposed recently to achieve switchable coupling between superconducting qubits. We discuss some of the main considerations regarding the feasibility of implementing one of those proposals: The double-resonance method. We analyze mainly issues related to the achievable effective coupling strength and the effects of crosstalk on this coupling mechanism. We also find a crosstalk-assisted coupling channel that can be an attractive alternative when implementing the double-resonance coupling proposal

  12. Stimulated resonance Raman spectroscopy: An alternative to laser-rf double resonance for ion spectroscopy

    International Nuclear Information System (INIS)

    Young, L.; Dinneen, T.; Mansour, N.B.

    1988-01-01

    Stimulated resonance Raman spectroscopy is presented as an alternative to laser-rf double resonance for obtaining high-precision measurements in ion beams. By use of a single-phase modulated laser beam to derive the two required fields, the laser--ion-beam alignment is significantly simplified. In addition, this method is especially useful in the low-frequency regime where the laser-rf double-resonance method encounters difficulties due to modifications of the ion-beam velocity distribution. These modifications, which result from interaction with the traveling rf wave used to induce magnetic dipole transitions, are observed and quantitatively modeled

  13. CP violation induced by the double resonance for pure annihilation decay process in perturbative QCD

    Energy Technology Data Exchange (ETDEWEB)

    Lue, Gang; Li, Sheng-Tao; Wang, Yu-Ting [Henan University of Technology, College of Science, Zhengzhou (China); Lu, Ye [Guangxi Normal University, Department of Physics, Guilin (China)

    2017-08-15

    In a perturbative QCD approach we study the direct CP violation in the pure annihilation decay process of anti B{sup 0}{sub s} → π{sup +}π{sup -}π{sup +}π{sup -} induced by the ρ and ω double resonance effect. Generally, the CP violation is small in the pure annihilation type decay process. However, we find that the CP violation can be enhanced by double ρ-ω interference when the invariant masses of the π{sup +}π{sup -} pairs are in the vicinity of the ω resonance. For the decay process of anti B{sup 0}{sub s} → π{sup +}π{sup -}π{sup +}π{sup -}, the CP violation can reach A{sub CP}(anti B{sup 0}{sub s} → π{sup +}π{sup -}π{sup +}π{sup -}) = 27.20{sup +0.05+0.28+7.13}{sub -0.15-0.31-6.11}%. (orig.)

  14. Carbon-deuterium rotational-echo double-resonance NMR spectroscopy of lyophilized aspartame formulations.

    Science.gov (United States)

    Luthra, Suman A; Utz, Marcel; Gorman, Eric M; Pikal, Michael J; Munson, Eric J; Lubach, Joseph W

    2012-01-01

    In this study, changes in the local conformation of aspartame were observed in annealed lyophilized glasses by monitoring changes in the distance between two labeled sites using C-(2)H rotational-echo double-resonance (REDOR) nuclear magnetic resonance (NMR) spectroscopy. Confirmation that the REDOR experiments were producing accurate distance measurement was ensured by measuring the (13)C-(15)N distance in glycine. The experiment was further verified by measuring the REDOR dephasing curve on (13)C-(2)H methionine. (13)C-(2)H REDOR dephasing curves were then measured on lyophilized aspartame-disaccharide formulations. In aspartame-sucrose formulation, the internuclear distances increased upon annealing, which correlated with decreased chemical reactivity. By contrast, annealing had only a minimal effect on the dephasing curve in aspartame-trehalose formulation. The results show that stability is a function of both mobility and local structure (conformation), even in a small molecule system such as lyophilized aspartame-sucrose. Copyright © 2011 Wiley-Liss, Inc.

  15. Isotopically selective RIMS of rare radionuclides by double-resonance excitation with cw lasers

    International Nuclear Information System (INIS)

    Bushaw, B.A.; Munley, J.T.

    1990-09-01

    Double-resonance, Resonance Ionization Mass Spectroscopy (RIMS) using two single-frequency dye lasers and a CO 2 laser for photoionization has been shown to be both extremely sensitive and highly selective. Measurements on the radioisotope 210 Pb have demonstrated optical selectivity in excess of 10 9 and detection limits of less than 1 femtogram

  16. 2H{ 19F} REDOR for distance measurements in biological solids using a double resonance spectrometer

    Science.gov (United States)

    Grage, Stephan L.; Watts, Jude A.; Watts, Anthony

    2004-01-01

    A new approach for distance measurements in biological solids employing 2H{ 19F} rotational echo double resonance was developed and validated on 2H, 19F- D-alanine and an imidazopyridine based inhibitor of the gastric H +/K +-ATPase. The 2H- 19F double resonance experiments presented here were performed without 1H decoupling using a double resonance NMR spectrometer. In this way, it was possible to benefit from the relatively longer distance range of fluorine without the need of specialized fluorine equipment. A distance of 2.5 ± 0.3 Å was measured in the alanine derivative, indicating a gauche conformation of the two labels. In the case of the imidazopyridine compound a lower distance limit of 5.2 Å was determined and is in agreement with an extended conformation of the inhibitor. Several REDOR variants were compared, and their advantages and limitations discussed. Composite fluorine dephasing pulses were found to enhance the frequency bandwidth significantly, and to reduce the dependence of the performance of the experiment on the exact choice of the transmitter frequency.

  17. Hyperfine structure of the X 2Σ+ ground state of Ca 35Cl and Ca 37Cl by molecular-beam, laser-rf double resonance

    International Nuclear Information System (INIS)

    Childs, W.J.; Cok, D.R.; Goodman, L.S.

    1982-01-01

    The hyperfine structure of the X 2 Σ + state of Ca 35 Cl and Ca 37 Cl, unresolved in previous studies, has been investigated in detail by the molecular-beam, laser-rf, double-resonance technique. Results for the spin-rotation interaction and the dipole and quadrupole hfs constants are given in the form of Dunham coefficients so that the N'' and v'' dependence of each constant can be explicitly exhibited. The results, after dividing out the purely nuclear effects, fall between the corresponding values for CaF and CaBr, as expected

  18. Electron-nuclear dynamics of molecular systems

    International Nuclear Information System (INIS)

    Diz, A.; Oehrn, Y.

    1994-01-01

    The content of an ab initio time-dependent theory of quantum molecular dynamics of electrons and atomic nuclei is presented. Employing the time-dependent variational principle and a family of approximate state vectors yields a set of dynamical equations approximating the time-dependent Schroedinger equation. These equations govern the time evolution of the relevant state vector parameters as molecular orbital coefficients, nuclear positions, and momenta. This approach does not impose the Born-Oppenheimer approximation, does not use potential energy surfaces, and takes into account electron-nuclear coupling. Basic conservation laws are fully obeyed. The simplest model of the theory employs a single determinantal state for the electrons and classical nuclei and is implemented in the computer code ENDyne. Results from this ab-initio theory are reported for ion-atom and ion-molecule collisions

  19. Modeling and characterization of double resonant tunneling diodes for application as energy selective contacts in hot carrier solar cells

    Science.gov (United States)

    Jehl, Zacharie; Suchet, Daniel; Julian, Anatole; Bernard, Cyril; Miyashita, Naoya; Gibelli, Francois; Okada, Yoshitaka; Guillemolles, Jean-Francois

    2017-02-01

    Double resonant tunneling barriers are considered for an application as energy selective contacts in hot carrier solar cells. Experimental symmetric and asymmetric double resonant tunneling barriers are realized by molecular beam epitaxy and characterized by temperature dependent current-voltage measurements. The negative differential resistance signal is enhanced for asymmetric heterostructures, and remains unchanged between low- and room-temperatures. Within Tsu-Esaki description of the tunnel current, this observation can be explained by the voltage dependence of the tunnel transmission amplitude, which presents a resonance under finite bias for asymmetric structures. This effect is notably discussed with respect to series resistance. Different parameters related to the electronic transmission of the structure and the influence of these parameters on the current voltage characteristic are investigated, bringing insights on critical processes to optimize in double resonant tunneling barriers applied to hot carrier solar cells.

  20. Free radicals imaged in vivo in the rat by using proton-electron double-resonance imaging

    International Nuclear Information System (INIS)

    Lurie, D.J.; Nicholson, Ian; Foster, M.A.; Mallard, J.R.

    1990-01-01

    A new technique called proton-electron double-resonance imaging is described for imaging free radicals in aqueous samples. The method is a combination of proton NMR imaging with nuclear electron double resonance. The results of using this technique to image free radicals in vivo in the rat are presented. Rats were injected intravenously with a nitroxide free radical solution and a series of images was obtained from which the clearance of the free radical through the liver and kidneys could be observed. (author)

  1. THz/Infrared Double Resonance Two-Photon Spectroscopy of HD+ for Determination of Fundamental Constants

    Directory of Open Access Journals (Sweden)

    Florin Lucian Constantin

    2017-10-01

    Full Text Available A double resonance two-photon spectroscopy scheme is discussed to probe jointly rotational and rovibrational transitions of ensembles of trapped HD+ ions. The two-photon transition rates and lightshifts are calculated with the two-photon tensor operator formalism. The rotational lines may be observed with sub-Doppler linewidth at the hertz level and good signal-to-noise ratio, improving the resolution in HD+ spectroscopy beyond the 10−12 level. The experimental accuracy, estimated at the 10−12 level, is comparable with the accuracy of theoretical calculations of HD+ energy levels. An adjustment of selected rotational and rovibrational HD+ lines may add clues to the proton radius puzzle, may provide an independent determination of the Rydberg constant, and may improve the values of proton-to-electron and deuteron-to-proton mass ratios beyond the 10−11 level.

  2. Conformational Structure of Tyrosine, Tyrosyl-Glycine, and Tyrosyl-Glycyl-Glycine by Double Resonance Spectroscopy

    Science.gov (United States)

    Abo-Riziq, Ali; Grace, Louis; Crews, Bridgit; Callahan, Michael P,; van Mourik, Tanja; de Vries, Mattanjah S,

    2011-01-01

    We investigated the variation in conformation for the amino acid tyrosine (Y), alone and in the small peptides tyrosine-glycine (YC) and tyrosine-glycine-glycine (YGG), in the gas phase by using UV-UV and IR-UV double resonance spectroscopy and density functional theory calculations. For tyrosine we found seven different conformations, for YG we found four different conformations, and for YGG we found three different conformations. As the peptides get larger, we observe fewer stable conformers, despite the increasing complexity and number of degrees of freedom. We find structural trends similar to those in phenylalanine-glycine glycine (FGG) and tryptophan-glycine-glycine (WGG)j however) the effect of dispersive forces in FGG for stabilizing a folded structure is replaced by that of hydrogen bonding in YGG.

  3. Rapid vibrational and rotational energy-transfer rates in heated carbon dioxide collisions by double-resonance laser spectroscopy

    International Nuclear Information System (INIS)

    Thomason, M.D.

    1982-07-01

    Rates for resonant vibrational and rotational energy transfer from the 001 state by CO 2 + CO 2 collisions have been measured. All data were obtained by double resonance spectroscopy with CO 2 lasers in a 2.5 meter absorption cell at 700 0 K. Results for rotation transfer include pumped-level relaxation and the response of other 001 levels with ΔJ up to 18. These data are compared to four relevant collision models via a 35-level rate equation analysis. Sequence-band (002 → 101) and hot-band (011 → 110) lasting have been used to observe resonant nu 3 -transfer relaxation involving 001 + 001 reversible 002 + 000, 001 + 100 reversible 101 + 000, and 001 + 010 reversible 011 + 000. A multilevel rate analysis has been utilized to determine the rate coefficients for 001 going to the 002, the 101, and the 011 levels. Part of the hot-band data has been interpreted as due to 110 + 000 reversible 100 + 010, and the associated rate constant has been estimated. The results of the study are compared to the theory and to other experiments

  4. Optimization of transversal relaxation of nitroxides for pulsed electron-electron double resonance spectroscopy in phospholipid membranes.

    Science.gov (United States)

    Dastvan, Reza; Bode, Bela E; Karuppiah, Muruga Poopathi Raja; Marko, Andriy; Lyubenova, Sevdalina; Schwalbe, Harald; Prisner, Thomas F

    2010-10-28

    Pulsed electron-electron double resonance (PELDOR) spectroscopy is increasingly applied to spin-labeled membrane proteins. However, after reconstitution into liposomes, spin labels often exhibit a much faster transversal relaxation (T(m)) than in detergent micelles, thus limiting application of the method in lipid bilayers. In this study, the main reasons for enhanced transversal relaxation in phospholipid membranes were investigated systematically by use of spin-labeled derivatives of stearic acid and phosphatidylcholine as well as spin-labeled derivatives of the channel-forming peptide gramicidin A under the conditions typically employed for PELDOR distance measurements. Our results clearly show that dephasing due to instantaneous diffusion that depends on dipolar interaction among electron spins is an important contributor to the fast echo decay in cases of high local concentrations of spin labels in membranes. The main difference between spin labels in detergent micelles and membranes is their local concentration. Consequently, avoiding spin clustering and suppressing instantaneous diffusion is the key step for maximizing PELDOR sensitivity in lipid membranes. Even though proton spin diffusion is an important relaxation mechanism, only in samples of low local concentrations does deuteration of acyl chains and buffer significantly prolong T(m). In these cases, values of up to 7 μs have been achieved. Furthermore, our study revealed that membrane composition and labeling position in the membrane can also affect T(m), either by promoting the segregation of spin-labeled species or by altering their exposure to matrix protons. Effects of other experimental parameters including temperature (<50 K), presence of oxygen, and cryoprotectant type are negligible under our experimental conditions.

  5. Electron spin-lattice relaxation mechanisms of radiation produced trapped electrons and hydrogen atoms in aqueous and organic glassy matrices. Modulation of electron nuclear dipolar interaction by tunnelling modes in a glassy matrix. [. gamma. rays

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, M K; Kevan, L [Wayne State Univ., Detroit, Mich. (USA). Dept. of Chemistry

    1977-01-01

    The spin lattice relaxation of trapped electrons in aqueous and organic glasses and trapped hydrogen atoms in phosphoric acid glass has been directly studied as a function of temperature by the saturation recovery method. Below 50 to 100 K, the major spin lattice relaxation mechanism involves modulation of the electron nuclear dipolar (END) interaction with nuclei in the radical's environment by tunnelling of those nuclei between two or more positions. This relaxation mechanism occurs with high efficiency and has a characteristic linear temperature dependence. The tunnelling nuclei around trapped electrons do not seem to involve the nearest neighbor nuclei which are oriented by the electron in the process of solvation. Instead the tunnelling nuclei typically appear to be next nearest neighbors to the trapped electron. The identities of the tunnelling nuclei have been deduced by isotopic substitution and are attributed to: Na in 10 mol dm/sup -3/ NaOH aqueous glass, ethyl protons in ethanol glass, methyl protons in methanol glass and methyl protons in MTHF glass. For trapped hydrogen atoms in phosphoric acid, the phosphorus nuclei appear to be the effective tunnelling nuclei. Below approximately 10 K the spin lattice relaxation is dominated by a temperature independent cross relaxation term for H atoms in phosphoric acid glass and for electrons in 10 mol dm/sup -3/ NaOH aqueous glass, but not for electrons in organic glasses. This is compared with recent electron-electron double resonance studies of cross relaxation in these glasses. The spin lattice relaxation of O/sup -/ formed in 10 mol dm/sup -3/ NaOH aqueous glass was also studied and found to be mainly dominated by a Raman process with an effective Debye temperature of about 100 K.

  6. Giant titanium electron wave function in gallium oxide: A potential electron-nuclear spin system for quantum information processing

    Science.gov (United States)

    Mentink-Vigier, Frédéric; Binet, Laurent; Vignoles, Gerard; Gourier, Didier; Vezin, Hervé

    2010-11-01

    The hyperfine interactions of the unpaired electron with eight surrounding G69a and G71a nuclei in Ti-doped β-Ga2O3 were analyzed by electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) spectroscopies. They are dominated by strong isotropic hyperfine couplings due to a direct Fermi contact interaction with Ga nuclei in octahedral sites of rutile-type chains oriented along b axis, revealing a large anisotropic spatial extension of the electron wave function. Titanium in β-Ga2O3 is thus best described as a diffuse (Ti4+-e-) pair rather than as a localized Ti3+ . Both electron and G69a nuclear spin Rabi oscillations could be observed by pulsed EPR and pulsed ENDOR, respectively. The electron spin decoherence time is about 1μs (at 4 K) and an upper bound of 520μs (at 8 K) is estimated for the nuclear decoherence time. Thus, β-Ga2O3:Ti appears to be a potential spin-bus system for quantum information processing with a large nuclear spin quantum register.

  7. In Vivo Application of Proton-Electron Double-Resonance Imaging

    Science.gov (United States)

    Kishimoto, Shun; Krishna, Murali C.; Khramtsov, Valery V.; Utsumi, Hideo

    2018-01-01

    Abstract Significance: Proton-electron double-resonance imaging (PEDRI) employs electron paramagnetic resonance irradiation with low-field magnetic resonance imaging so that the electron spin polarization is transferred to nearby protons, resulting in higher signals. PEDRI provides information about free radical distribution and, indirectly, about the local microenvironment such as partial pressure of oxygen (pO2), tissue permeability, redox status, and acid-base balance. Recent Advances: Local acid-base balance can be imaged by exploiting the different resonance frequency of radical probes between R and RH+ forms. Redox status can also be imaged by using the loss of radical-related signal after reduction. These methods require optimized radical probes and pulse sequences. Critical Issues: High-power radio frequency irradiation is needed for optimum signal enhancement, which may be harmful to living tissue by unwanted heat deposition. Free radical probes differ depending on the purpose of PEDRI. Some probes are less effective for enhancing signal than others, which can reduce image quality. It is so far not possible to image endogenous radicals by PEDRI because low concentrations and broad line widths of the radicals lead to negligible signal enhancement. Future Directions: PEDRI has similarities with electron paramagnetic resonance imaging (EPRI) because both techniques observe the EPR signal, directly in the case of EPRI and indirectly with PEDRI. PEDRI provides information that is vital to research on homeostasis, development of diseases, or treatment responses in vivo. It is expected that the development of new EPR techniques will give insights into novel PEDRI applications and vice versa. Antioxid. Redox Signal. 28, 1345–1364. PMID:28990406

  8. CO2-laser-microwave double-resonance spectroscopy of D2CO: precise measurement of the dipole moment in the ground state

    International Nuclear Information System (INIS)

    Tanaka, K.; Nakahara, Y.; Yamaguchi, M.; Tanaka, T.

    1987-01-01

    The method of CO 2 -laser-microwave double resonance (LMDR) with an intense electric field was used to measure Stark shifts of ground-state microwave transitions of D 2 CO. Thirty LMDR signals originating from 15 K-doublet transitions were observed, associated with the infrared transitions of the ν 4 and ν 6 bands. Least-squares analysis of the observed LMDR signals yields precise values of the coefficients in the dipole-moment expansion, μ 0 +μ/sub J/ J(J+1)+μ/sub K/ K 2 : μ 0 , 2.347 134(8) D; μ/sub j/, -4.76(10) x 10 -6 D; μ/sub K/, -28.7(18) x 10 -6 D; where one-standard-deviation uncertainties are given in parentheses. The infrared--infrared double-resonance signals of PH 3 , which were calibrated against the OCS dipole moment, were used for the electric-field calibration, allowing us to determine the dipole moment with a precision of 10 parts in 10 6 (ppm). However, the absolute accuracy of the dipole moment obtained is 50 ppm, as limited by the uncertainty of the OCS dipole moment. The effective dipole moment for the 1/sub 1.0/ reverse arrow 1/sub 1.1/ transition measured in the present study agrees well with the effective dipole moment for the 1/sub 1.0/ rotational level from a molecular-beam electric resonance experiment. The μ/sub J/ and μ/sub K/ coefficients calculated from Watson's θ/sub γ//sup α//sup β/ constants agree well with the experimental values

  9. High-precision hyperfine structure measurement in slow atomic ion beams by collinear laser-rf double resonance

    International Nuclear Information System (INIS)

    Amarjit Sen; Childs, W.J.; Goodman, L.S.

    1987-01-01

    A new collinear laser-ion beam apparatus for slow ions (1 to 1.5 keV) has been built for measuring the hyperfine structure of metastable levels of ions with laser-rf double resonance technique. Narrow linewidths of ∼60 kHz (FWHM) have been observed for the first time in such systems. As a first application the hyperfine structure of the 4f 7 ( 8 S 0 )5d 9 D/sub J/ 0 metastable levels of /sup 151,153/Eu + has been measured with high precision. 10 refs., 8 figs

  10. Observation of strongly forbidden solid effect dynamic nuclear polarization transitions via electron-electron double resonance detected NMR

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Albert A.; Corzilius, Björn; Haze, Olesya; Swager, Timothy M.; Griffin, Robert G., E-mail: rgg@mit.edu [Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2013-12-07

    We present electron paramagnetic resonance experiments for which solid effect dynamic nuclear polarization transitions were observed indirectly via polarization loss on the electron. This use of indirect observation allows characterization of the dynamic nuclear polarization (DNP) process close to the electron. Frequency profiles of the electron-detected solid effect obtained using trityl radical showed intense saturation of the electron at the usual solid effect condition, which involves a single electron and nucleus. However, higher order solid effect transitions involving two, three, or four nuclei were also observed with surprising intensity, although these transitions did not lead to bulk nuclear polarization—suggesting that higher order transitions are important primarily in the transfer of polarization to nuclei nearby the electron. Similar results were obtained for the SA-BDPA radical where strong electron-nuclear couplings produced splittings in the spectrum of the indirectly observed solid effect conditions. Observation of high order solid effect transitions supports recent studies of the solid effect, and suggests that a multi-spin solid effect mechanism may play a major role in polarization transfer via DNP.

  11. Infrared-ultraviolet double resonance: studies of molecular spectroscopy and energy transfer

    International Nuclear Information System (INIS)

    Orr, B.J.; Nutt, G.F.

    1980-01-01

    The paper demonstrates that, within the context of characterizing interactions between molecules, a new source of experimental data has become available. Recent apparatus modifications have resulted in substantially improved control of the delay between pump and probe laser pulses, with consequently improved signal-to-noise ratio and time resolution. A new phase of investigation is now underway to determine quantitively rotational relaxation rate constants as a function of angular momentum state and to model these in an appropriate fashion

  12. Electronic Structure of ZnO Quantum Dots studied by High-frequency EPR, ESE, ENDOR and ODMR Spectroscopy

    NARCIS (Netherlands)

    Baranov, P.G.; Romanov, N.G.; Bundakova, A.P.; de Mello-Donega, Celso; Schmidt, J.

    2016-01-01

    High-frequency electron paramagnetic resonance (EPR), electron spin echo (ESE), electron-nuclear double resonance (ENDOR) and optically detected magnetic resonance (ODMR) were applied for the investigation of the electronic properties of ZnO colloidal quantum dots (QDs) which consist of a ZnO

  13. Focus: Two-dimensional electron-electron double resonance and molecular motions: The challenge of higher frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Franck, John M.; Chandrasekaran, Siddarth; Dzikovski, Boris; Dunnam, Curt R.; Freed, Jack H., E-mail: jhf3@cornell.edu [Department of Chemistry and Chemical Biology and National Biomedical Center for Advanced ESR Technology, Cornell University, Ithaca, New York 14853 (United States)

    2015-06-07

    The development, applications, and current challenges of the pulsed ESR technique of two-dimensional Electron-Electron Double Resonance (2D ELDOR) are described. This is a three-pulse technique akin to 2D Exchange Nuclear Magnetic Resonance, but involving electron spins, usually in the form of spin-probes or spin-labels. As a result, it required the extension to much higher frequencies, i.e., microwaves, and much faster time scales, with π/2 pulses in the 2-3 ns range. It has proven very useful for studying molecular dynamics in complex fluids, and spectral results can be explained by fitting theoretical models (also described) that provide a detailed analysis of the molecular dynamics and structure. We discuss concepts that also appear in other forms of 2D spectroscopy but emphasize the unique advantages and difficulties that are intrinsic to ESR. Advantages include the ability to tune the resonance frequency, in order to probe different motional ranges, while challenges include the high ratio of the detection dead time vs. the relaxation times. We review several important 2D ELDOR studies of molecular dynamics. (1) The results from a spin probe dissolved in a liquid crystal are followed throughout the isotropic → nematic → liquid-like smectic → solid-like smectic → crystalline phases as the temperature is reduced and are interpreted in terms of the slowly relaxing local structure model. Here, the labeled molecule is undergoing overall motion in the macroscopically aligned sample, as well as responding to local site fluctuations. (2) Several examples involving model phospholipid membranes are provided, including the dynamic structural characterization of the boundary lipid that coats a transmembrane peptide dimer. Additionally, subtle differences can be elicited for the phospholipid membrane phases: liquid disordered, liquid ordered, and gel, and the subtle effects upon the membrane, of antigen cross-linking of receptors on the surface of plasma membrane

  14. Focus: Two-dimensional electron-electron double resonance and molecular motions: The challenge of higher frequencies

    International Nuclear Information System (INIS)

    Franck, John M.; Chandrasekaran, Siddarth; Dzikovski, Boris; Dunnam, Curt R.; Freed, Jack H.

    2015-01-01

    The development, applications, and current challenges of the pulsed ESR technique of two-dimensional Electron-Electron Double Resonance (2D ELDOR) are described. This is a three-pulse technique akin to 2D Exchange Nuclear Magnetic Resonance, but involving electron spins, usually in the form of spin-probes or spin-labels. As a result, it required the extension to much higher frequencies, i.e., microwaves, and much faster time scales, with π/2 pulses in the 2-3 ns range. It has proven very useful for studying molecular dynamics in complex fluids, and spectral results can be explained by fitting theoretical models (also described) that provide a detailed analysis of the molecular dynamics and structure. We discuss concepts that also appear in other forms of 2D spectroscopy but emphasize the unique advantages and difficulties that are intrinsic to ESR. Advantages include the ability to tune the resonance frequency, in order to probe different motional ranges, while challenges include the high ratio of the detection dead time vs. the relaxation times. We review several important 2D ELDOR studies of molecular dynamics. (1) The results from a spin probe dissolved in a liquid crystal are followed throughout the isotropic → nematic → liquid-like smectic → solid-like smectic → crystalline phases as the temperature is reduced and are interpreted in terms of the slowly relaxing local structure model. Here, the labeled molecule is undergoing overall motion in the macroscopically aligned sample, as well as responding to local site fluctuations. (2) Several examples involving model phospholipid membranes are provided, including the dynamic structural characterization of the boundary lipid that coats a transmembrane peptide dimer. Additionally, subtle differences can be elicited for the phospholipid membrane phases: liquid disordered, liquid ordered, and gel, and the subtle effects upon the membrane, of antigen cross-linking of receptors on the surface of plasma membrane

  15. Electron-nuclear magnetic resonance in the inverted state

    International Nuclear Information System (INIS)

    Ignatchenko, V.A.; Tsifrinovich, V.I.

    1975-01-01

    The paper considers the susceptibility of the electron-nucleus system of a ferromagnet when nuclear magnetization is inverted with respect to the hyperfine field direction. The inverted state is a situation in which nuclear magnetization is turned through π relative to its equilibrium orientation, whereas electron magnetization is in an equilibrium state with respect to an external magnetic field. The consideration is carried out for a thin plate magnetized in its plane. Amplification of a weak radiofrequency signal can be attained under the fulfilment of an additional inequality relating the interaction frequency with electron and nuclear relaxation parameters. The gain may exceed the gain for an inverted nuclear system in magnetically disordered substances. In the range of strong interaction between the frequencies of ferromagnetic (FMR) and nuclear magnetic (NMR) resonances the electron-nuclear magnetic resonance (ENMR) spectrum possesses a fine structure which is inverse to that obtained for the ENMR spectrum in a normal state. The inverted state ENMR line shape is analysed in detail for the case of so weak HF fields that the relaxation conditions may be regarded as stationary. The initial (linear) stages of a forced transient process arising in an electron-nuclear system under the effect of a strong HF field are briefly analysed

  16. Effects of ionizing radiation in cocrystals of DNA model compounds: ESR-ENDOR studies of X-irradiated imidazole:barbital and adenosine:5-bromouracil

    International Nuclear Information System (INIS)

    Kar, L.

    1982-01-01

    Electron spin resonance (ESR) and electron nuclear double resonance (ENDOR) techniques have been used to study radiation induced damage in cocrystalline complexes X-irradiated at 12 K. The study addresses the following questions: (1) whether radiation induced damage is stabilized preferentially on one of the components of the cocrystalline system; and (2) whether charge transfer occurs between purine and pyrimidine bases in hydrogen bonded or stacked configurations. The cocrystals used in this study are imidazole:5,5-diethylbarbituric acid (barbital) and adenosine:5-bromouracil (AR:BU). Results indicate that (1) preferential stability of radiation damage may be observed in a cocrystal even in the absence of stacking interactions; (2) in the presence of purine:pyrimidine stacking electron transfer may occur, but hole transfer is not likely to be the mechanism of redistribution of radiation damage in cocrystalline systems. The radiation chemistry of AR:BU is used as a model to predict the effects of ionizing radiation on DNA

  17. Electron-nuclear corellations for photoinduced dynamics in molecular dimers

    Science.gov (United States)

    Kilin, Dmitri S.; Pereversev, Yuryi V.; Prezhdo, Oleg V.

    2003-03-01

    Ultrafast photoinduced dynamics of electronic excitation in molecular dimers is drastically affected by dynamic reorganization of of inter- and intra- molecular nuclear configuration modelled by quantized nuclear degree of freedom [1]. The dynamics of the electronic population and nuclear coherence is analyzed with help of both numerical solution of the chain of coupled differential equations for mean coordinate, population inversion, electronic-vibrational correlation etc.[2] and by propagating the Gaussian wavepackets in relevant adiabatic potentials. Intriguing results were obtained in the approximation of small energy difference and small change of nuclear equilibrium configuration for excited electronic states. In the limiting case of resonance between electronic states energy difference and frequency of the nuclear mode these results have been justified by comparison to exactly solvable Jaynes-Cummings model. It has been found that the photoinduced processes in dimer are arranged according to their time scales:(i) fast scale of nuclear motion,(ii) intermediate scale of dynamical redistribution of electronic population between excited states as well as growth and dynamics of electronic -nuclear correlation,(iii) slow scale of electronic population approaching to the quasiequilibrium distribution, decay of electronic-nuclear correlation, and diminishing the amplitude of mean coordinate oscillations, accompanied by essential growth of the nuclear coordinate dispersion associated with the overall nuclear wavepacket width. Demonstrated quantum-relaxational features of photoinduced vibronic dinamical processess in molecular dimers are obtained by simple method, applicable to large biological systems with many degrees of freedom. [1] J. A. Cina, D. S. Kilin, T. S. Humble, J. Chem. Phys. (2003) in press. [2] O. V. Prezhdo, J. Chem. Phys. 117, 2995 (2002).

  18. ESR-ENDOR study of x-irradiated single crystals of α.D.glucopyranose and α-methyl.D.glucopyranoside; environmental effects upon radiation and free radical chemistry in carbohydrate model systems

    International Nuclear Information System (INIS)

    Madden, K.P.

    1980-01-01

    Single crystals of x-irradiated α-D-glucopyranose (αGlu) and α-methyl-D-glucopyranoside (αMeGlu) were studied using electron spin resonance and electron nuclear double resonance spectroscopy, to determine products and reaction mechanisms in carbohydrate radiation and free-radical chemistry. Four free-radical products were identified in αMeGlu single crystals irradiated and studied at 77K. Irradiation and observation at 12K produced yet another species. Four free radicals were identified in αGlu single crystals irradiated and observed at 12K and 77K. Free radical reaction in αGlu and αMeGlu were induced by slowly warming crystals irradiated at 77K until conversion occurred. Environmental influences upon these free-radical reaction mechanisms are discussed. The results from previous work on irradiated aqueous glasses of αGlu is briefly reviewed, and compared to those obtained from the single crystal system

  19. Optical-optical double resonance, laser induced fluorescence, and revision of the signs of the spin-spin constants of the boron carbide (BC) free radical

    Science.gov (United States)

    Sunahori, Fumie X.; Nagarajan, Ramya; Clouthier, Dennis J.

    2015-12-01

    The cold boron carbide free radical (BC X 4Σ-) has been produced in a pulsed discharge free jet expansion using a precursor mixture of trimethylborane in high pressure argon. High resolution laser induced fluorescence spectra have been obtained for the B 4Σ--X 4Σ- and E 4Π-X 4Σ- band systems of both 11BC and 10BC. An optical-optical double resonance (OODR) scheme was implemented to study the finer details of both band systems. This involved pumping a single rotational level of the B state with one laser and then recording the various allowed transitions from the intermediate B state to the final E state with a second laser by monitoring the subsequent E-X ultraviolet fluorescence. In this fashion, we were able to prove unambiguously that, contrary to previous studies, the spin-spin constant λ is negative in the ground state and positive in the B 4Σ- excited state. It has been shown that λ″ expected based on a semiempirical second order perturbation theory calculation of the magnitude of the spin-spin constant. The OODR spectra have also been used to validate our assignments of the complex and badly overlapped E 4Π-X 4Σ- 0-0 and 1-0 bands of 11BC. The E-X 0-0 band of 10BC was found to be severely perturbed. The ground state main electron configuration is …3σ24σ25σ11π22π0 and the derived bond lengths show that there is a 0.03 Å contraction in the B state, due to the promotion of an electron from the 4σ antibonding orbital to the 5σ bonding orbital. In contrast, the bond length elongates by 0.15 Å in the E state, a result of promoting an electron from the 5σ bonding orbital to the 2π antibonding orbitals.

  20. Polarization dependence of double-resonance optical pumping and electromagnetically induced transparency in the 5S1/2-5P3/2-5D5/2 transition of 87Rb atoms

    International Nuclear Information System (INIS)

    Moon, Han Seb; Noh, Heung-Ryoul

    2011-01-01

    The polarization dependence of double-resonance optical pumping (DROP) in the ladder-type electromagnetically induced transparency (EIT) of the 5S 1/2 -5P 3/2 -5D 5/2 transition of 87 Rb atoms is studied. The transmittance spectra in the 5S 1/2 (F=2)-5P 3/2 (F'=3)-5D 5/2 (F''=2,3,4) transition were observed as caused by EIT, DROP, and saturation effects in the various polarization combinations between the probe and coupling lasers. The features of the double-structure transmittance spectra in the 5S 1/2 (F=2)-5P 3/2 (F'=3)-5D 5/2 (F''=4) cycling transition were attributed to the difference in saturation effect according to the transition routes between the Zeeman sublevels and the EIT according to the two-photon transition probability.

  1. Microwave-optical double resonance spectroscopy. Progress report, February 1, 1975--January 31, 1976

    International Nuclear Information System (INIS)

    Pratt, D.W.

    1975-01-01

    Zero-field and high-field optical detection of magnetic resonance (ODMR), electron paramagnetic resonance (EPR), and optical spectroscopy experiments were performed on several systems in order to further basic knowledge of the structure, reactions, and response to radiation of atoms, molecules, and ions. Results on the following studies are reported: the direct observation of level anticrossing and mixing effects in excited molecular triplet states; anomalous zero-field splittings in the lowest triplet state of 1-iodonaphthalene; evidence for second-order spin-orbit coupling and spin delocalization effects in the lowest triplet state of benzophenone; direct observation of the optical absorption spectra of reactive free radicals at room temperature; measurements of the activation and thermodynamic parameters of several cyclohexenyl and cyclohexanonyl radicals; complete analyses of the level anticrossing and cross relaxation spectra of oriented molecular triplet states; solutions to the spin Hamiltonian for S = 1, I = 5/2 systems in both zero-field and high-field, an improvement by a factor of ten in the resolution of ODMR experiments in high field; and measurements of the optical and magnetic resonance properties of a series of halogenated naphthalenes in their lowest triplet states

  2. Optical-optical double resonance, laser induced fluorescence, and revision of the signs of the spin-spin constants of the boron carbide (BC) free radical

    Energy Technology Data Exchange (ETDEWEB)

    Sunahori, Fumie X. [Department of Chemistry and Physics, Franklin College, Franklin, Indiana 46131 (United States); Nagarajan, Ramya; Clouthier, Dennis J., E-mail: dclaser@uky.edu [Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055 (United States)

    2015-12-14

    The cold boron carbide free radical (BC X {sup 4}Σ{sup −}) has been produced in a pulsed discharge free jet expansion using a precursor mixture of trimethylborane in high pressure argon. High resolution laser induced fluorescence spectra have been obtained for the B {sup 4}Σ{sup −}–X {sup 4}Σ{sup −} and E {sup 4}Π–X {sup 4}Σ{sup −} band systems of both {sup 11}BC and {sup 10}BC. An optical-optical double resonance (OODR) scheme was implemented to study the finer details of both band systems. This involved pumping a single rotational level of the B state with one laser and then recording the various allowed transitions from the intermediate B state to the final E state with a second laser by monitoring the subsequent E–X ultraviolet fluorescence. In this fashion, we were able to prove unambiguously that, contrary to previous studies, the spin-spin constant λ is negative in the ground state and positive in the B {sup 4}Σ{sup −} excited state. It has been shown that λ″ < 0 is in fact expected based on a semiempirical second order perturbation theory calculation of the magnitude of the spin-spin constant. The OODR spectra have also been used to validate our assignments of the complex and badly overlapped E {sup 4}Π–X {sup 4}Σ{sup −} 0-0 and 1-0 bands of {sup 11}BC. The E–X 0-0 band of {sup 10}BC was found to be severely perturbed. The ground state main electron configuration is …3σ{sup 2}4σ{sup 2}5σ{sup 1}1π{sup 2}2π{sup 0} and the derived bond lengths show that there is a 0.03 Å contraction in the B state, due to the promotion of an electron from the 4σ antibonding orbital to the 5σ bonding orbital. In contrast, the bond length elongates by 0.15 Å in the E state, a result of promoting an electron from the 5σ bonding orbital to the 2π antibonding orbitals.

  3. Quantum Nuclear Extension of Electron Nuclear Dynamics on Folded Effective-Potential Surfaces

    DEFF Research Database (Denmark)

    Hall, B.; Deumens, E.; Ohrn, Y.

    2014-01-01

    A perennial problem in quantum scattering calculations is accurate theoretical treatment of low energy collisions. We propose a method of extracting a folded, nonadiabatic, effective potential energy surface from electron nuclear dynamics (END) trajectories; we then perform nuclear wave packet...

  4. Stark effect investigations of excited cadmium, ytterbium, and thulium I-levels using the methods of double resonance and level crossing

    International Nuclear Information System (INIS)

    Rinkleff, R.H.

    1977-01-01

    Using the method of optical double resonance, the 5s5p 3 P 1 level tensor polarizability of Cadmium has been measured. For this state, various authors have published different results, using different experimental methods. The experimental result presented here is in excellent agreement with the value of Happer, based on level crossing investigations, and agrees well with the theoretical result of Robinson based on a modified Sternheimer approximation, and so gives a reliable value for the tensor polarizability. Furthermore the tensor polarizability of the 6s6p 3 P 1 - level of the even Ytterbium isotopes and the odd Ytterbium 171 nucleus have been measured with the optical double resonance method, and the Stark constant has been calculated based on a given theory and oscillator strengths. Using the methods of optical double resonance and level crossing, the tensor polarizability of 5 excited levels of the Thulium configurations 4f 13 6s6p + 4f 12 5d6s 2 have been measured. From the experimental Stark constants and the angular coefficients of the eigenfunctions calculated by Camus, the radial integrals I(5d, 5p) and I(6p, 5d) are calculated for electric dipole transitions between levels of the configurations 4f 12 5d6s 2 + 4f 13 6s6p and levels of the 4f 12 6p6s 2 + 4f 13 6s5d configurations. The tensor polarizability calculated with these radial integrals show very good agreement with the experimental values. (orig./LH) [de

  5. Observation of double resonant laser induced transitions in the $v = n - l - 1 = 2$ metastable cascade of antiprotonic helium-4 atoms

    CERN Document Server

    Hayano, R S; Tamura, H; Torii, H A; Hori, Masaki; Maas, F E; Morita, N; Kumakura, M; Sugai, I; Hartmann, F J; Daniel, H; Von Egidy, T; Ketzer, B; Pohl, R; Horváth, D; Eades, John; Widmann, E; Yamazaki, T

    1997-01-01

    A new laser-induced resonant transition in the $v=n-l-1=2$ metastable cascade of antiprotonic $^4$He atoms has been found by using a double resonance technique. This was done by setting the first laser to the already known 470.724 nm resonance ($(n,l)=(37,34)\\rightarrow (36,33)$), while the $(38,35)\\rightarrow (37,34)$ transition was searched for with the second laser. The resonant transition was found at wavelength of 529.622$\\pm$0.003 nm, showing excellent agreement with a recent prediction of Korobov.

  6. Double resonance capacitance spectroscopy (DORCAS): A new experimental technique for assignment of X-ray absorption peaks to surface sites of semiconductor

    CERN Document Server

    Ishii, M

    2003-01-01

    As a new microspectroscopy for semiconductor surface analysis using an X-ray beam, double resonance capacitance spectroscopy (DORCAS) is proposed. For a microscopic X-ray absorption measurement, a local capacitance change owing to X-ray induced emission of localized electrons is detected by a microprobe. The applied bias voltage V sub b dependence of the capacitance also provides information on the surface density of state. The resonance of the Fermi energy with a surface level by V sub b control makes possible the selection of the observable surface site in the X-ray absorption measurements, i.e. site-specific spectroscopy. The double resonance of the surface site selection (V sub b resonance) and the resonant X-ray absorption of the selected site (photon energy h nu resonance) enhances the capacitance signal. The DORCAS measurement of the GaAs surface shows correlation peaks at h nu=10.402 keV and V sub b =-0.4 V and h nu=10.429 keV and V sub b =+0.1 V, indicating that these resonant X-ray absorption peaks ...

  7. The electron-nuclear spin system in (In,Ga)As quantum dots

    International Nuclear Information System (INIS)

    Auer, Thomas

    2008-01-01

    For a long time, the nuclear spins in quantum dots were virtually ignored. It was thought that the interaction strength was so small that the interaction between the nuclei and electrons could only be observed under very specific optical pumping conditions. Then, in the pursuit of long living electron spins as a building block for quantum information storage and processing, their destructive action on the lifetime of the electron spin became apparent. The nuclear spin system increasingly gained the attention of the quantum dot community. It seemed that the randomly oriented, fluctuating nuclear spins can only be counteracted by strong magnetic fields suppressing the depolarising effect of the random nuclear spin fluctuation fields on a single electron spin. Gradually, however, the work done thirty years before on the electron-nuclear spin system in bulk semiconductors attracted the notice of scientists again. Some of the old experiments could be performed with quantum dots as well. It could be shown that the nuclear spins in quantum dots may well be polarised by optical orientation and that their action is not always destructive at all. The nuclear spins in quantum dots are increasingly used in order to create and tailor a specific environment for a single electron in a quantum dot. In this way quantum dots contain their own ''nuclear nanomagnet''. This might be the future of the studies on the electron-nuclear spin system. The aim of this work is to shed some more light on the complex interdependent system formed of an electron spin and the nuclear spin ensemble in quantum dots. The effects are manifold, often unexpected, sometimes miraculous. Nevertheless, I believe that this work is another tiny step towards the understanding of this challenging system. I have shown that the randomly polarised nuclear spin system always affects the electron spin of a single electron in quantum dots. Further we have seen, however, that the nuclear spin system can easily be

  8. Double-resonance optical-pumping effect and ladder-type electromagnetically induced transparency signal without Doppler background in cesium atomic vapour cell

    International Nuclear Information System (INIS)

    Yang Bao-Dong; Gao Jing; Liang Qiang-Bing; Wang Jie; Zhang Tian-Cai; Wang Jun-Min

    2011-01-01

    In a Doppler-broadened ladder-type cesium atomic system (6S 1/2 -6P 3/2 -8S 1/2 ), this paper characterizes electromagnetically induced transparency (EIT) in two different experimental arrangements, and investigates the influence of the double-resonance optical-pumping (DROP) effect on EIT in both arrangements. When the probe laser is weak, DROP is explicitly suppressed. When the probe laser is moderate, population of the intermediate level (6P 3/2 F' = 5) is remarkable, therefore DROP is mixed with EIT. An interesting bimodal spectrum with the broad component due to DROP and the narrow part due to EIT has been clearly observed in cesium 6S 1/2 F = 4−6P 3/2 F' = 5−8S 1/2 F″ = 4 transitions. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  9. Assessment of amide I spectroscopic maps for a gas-phase peptide using IR-UV double-resonance spectroscopy and density functional theory calculations

    Energy Technology Data Exchange (ETDEWEB)

    Carr, J. K.; Roy, S.; Skinner, J. L. [Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin, Madison, Wisconsin 53706 (United States); Zabuga, A. V.; Rizzo, T. R. [Laboratoire de Chimie Physique Moleculaire, Ecole Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCPM, Station 6, CH-1015 Lausanne (Switzerland)

    2014-06-14

    The spectroscopy of amide I vibrations has become a powerful tool for exploring protein structure and dynamics. To help with spectral interpretation, it is often useful to perform molecular dynamics (MD) simulations. To connect spectroscopic experiments to simulations in an efficient manner, several researchers have proposed “maps,” which relate observables in classical MD simulations to quantum spectroscopic variables. It can be difficult to discern whether errors in the theoretical results (compared to experiment) arise from inaccuracies in the MD trajectories or in the maps themselves. In this work, we evaluate spectroscopic maps independently from MD simulations by comparing experimental and theoretical spectra for a single conformation of the α-helical model peptide Ac-Phe-(Ala){sub 5}-Lys-H{sup +} in the gas phase. Conformation-specific experimental spectra are obtained for the unlabeled peptide and for several singly and doubly {sup 13}C-labeled variants using infrared-ultraviolet double-resonance spectroscopy, and these spectra are found to be well-modeled by density functional theory (DFT) calculations at the B3LYP/6-31G** level. We then compare DFT results for the deuterated and {sup 13}C{sup 18}O-labeled peptide with those from spectroscopic maps developed and used previously by the Skinner group. We find that the maps are typically accurate to within a few cm{sup −1} for both frequencies and couplings, having larger errors only for the frequencies of terminal amides.

  10. Assessment of amide I spectroscopic maps for a gas-phase peptide using IR-UV double-resonance spectroscopy and density functional theory calculations

    International Nuclear Information System (INIS)

    Carr, J. K.; Roy, S.; Skinner, J. L.; Zabuga, A. V.; Rizzo, T. R.

    2014-01-01

    The spectroscopy of amide I vibrations has become a powerful tool for exploring protein structure and dynamics. To help with spectral interpretation, it is often useful to perform molecular dynamics (MD) simulations. To connect spectroscopic experiments to simulations in an efficient manner, several researchers have proposed “maps,” which relate observables in classical MD simulations to quantum spectroscopic variables. It can be difficult to discern whether errors in the theoretical results (compared to experiment) arise from inaccuracies in the MD trajectories or in the maps themselves. In this work, we evaluate spectroscopic maps independently from MD simulations by comparing experimental and theoretical spectra for a single conformation of the α-helical model peptide Ac-Phe-(Ala) 5 -Lys-H + in the gas phase. Conformation-specific experimental spectra are obtained for the unlabeled peptide and for several singly and doubly 13 C-labeled variants using infrared-ultraviolet double-resonance spectroscopy, and these spectra are found to be well-modeled by density functional theory (DFT) calculations at the B3LYP/6-31G** level. We then compare DFT results for the deuterated and 13 C 18 O-labeled peptide with those from spectroscopic maps developed and used previously by the Skinner group. We find that the maps are typically accurate to within a few cm −1 for both frequencies and couplings, having larger errors only for the frequencies of terminal amides

  11. Assessment of amide I spectroscopic maps for a gas-phase peptide using IR-UV double-resonance spectroscopy and density functional theory calculations

    Science.gov (United States)

    Carr, J. K.; Zabuga, A. V.; Roy, S.; Rizzo, T. R.; Skinner, J. L.

    2014-01-01

    The spectroscopy of amide I vibrations has become a powerful tool for exploring protein structure and dynamics. To help with spectral interpretation, it is often useful to perform molecular dynamics (MD) simulations. To connect spectroscopic experiments to simulations in an efficient manner, several researchers have proposed “maps,” which relate observables in classical MD simulations to quantum spectroscopic variables. It can be difficult to discern whether errors in the theoretical results (compared to experiment) arise from inaccuracies in the MD trajectories or in the maps themselves. In this work, we evaluate spectroscopic maps independently from MD simulations by comparing experimental and theoretical spectra for a single conformation of the α-helical model peptide Ac-Phe-(Ala)5-Lys-H+ in the gas phase. Conformation-specific experimental spectra are obtained for the unlabeled peptide and for several singly and doubly 13C-labeled variants using infrared-ultraviolet double-resonance spectroscopy, and these spectra are found to be well-modeled by density functional theory (DFT) calculations at the B3LYP/6-31G** level. We then compare DFT results for the deuterated and 13C18O-labeled peptide with those from spectroscopic maps developed and used previously by the Skinner group. We find that the maps are typically accurate to within a few cm−1 for both frequencies and couplings, having larger errors only for the frequencies of terminal amides. PMID:24929378

  12. Consistent quantum approach to new laser-electron-nuclear effects in diatomic molecules

    International Nuclear Information System (INIS)

    Glushkov, A V; Malinovskaya, S V; Loboda, A V; Shpinareva, I M; Prepelitsa, G P

    2006-01-01

    We present a consistent, quantum approach to the calculation of electron-nuclear γ. spectra (set of vibrational and rotational satellites) for nuclei in diatomic molecules. The approach generelizes the well known Letokhov-Minogin model and is based on the Dunham model potential approximation for potential curves of diatomic molecules. The method is applied to the calculation of probabilities of the vibration-rotation-nuclear transitions in a case of emission and absorption spectrum for the nucleus 127 I (E γ (0) = 203 keV) linked with the molecule H 127 I

  13. Stabilization of the Electron-Nuclear Spin Orientation in Quantum Dots by the Nuclear Quadrupole Interaction

    Science.gov (United States)

    Dzhioev, R. I.; Korenev, V. L.

    2007-07-01

    The nuclear quadrupole interaction eliminates the restrictions imposed by hyperfine interaction on the spin coherence of an electron and nuclei in a quantum dot. The strain-induced nuclear quadrupole interaction suppresses the nuclear spin flip and makes possible the zero-field dynamic nuclear polarization in self-organized InP/InGaP quantum dots. The direction of the effective nuclear magnetic field is fixed in space, thus quenching the magnetic depolarization of the electron spin in the quantum dot. The quadrupole interaction suppresses the zero-field electron spin decoherence also for the case of nonpolarized nuclei. These results provide a new vision of the role of the nuclear quadrupole interaction in nanostructures: it elongates the spin memory of the electron-nuclear system.

  14. Room temperature Q-band electron magnetic resonance study of radicals in X-ray-irradiated L-threonine single crystals

    International Nuclear Information System (INIS)

    Vanhaelewyn, Gauthier; Vrielinck, Henk; Callens, Freddy

    2014-01-01

    In the past, decennia radiation-induced radicals were successfully identified by electron magnetic resonance (EMR) in several solid-state amino acids and sugars. The authors present a room temperature (RT) EMR study of the stable radicals produced by X-ray-irradiation in the amino acid L-threonine (CH 3 CH(OH)CH(NH3 + )COO - ). Its chemical structure is similar to that of the well-known dosimetric material L-alanine (CH 3 CH(NH3 + )COO - ), and radiation defects in L-threonine may straightforwardly be compared with the extensively studied L-alanine radicals. The hyperfine coupling tensors of three different radicals were determined at RT using electron nuclear double resonance. These results indicate that the two most abundant radicals share the same basic structure CH 3 .C(OH)CH(NH3 + )COO - , obtained by H-abstraction, but are stabilised in slightly different conformations. The third radical is most probably obtained by deamination (CH 3 CH(OH).CHCOO - ), similar in structure to the stable alanine radical. (authors)

  15. Intersubunit distances in full-length, dimeric, bacterial phytochrome Agp1, as measured by pulsed electron-electron double resonance (PELDOR) between different spin label positions, remain unchanged upon photoconversion.

    Science.gov (United States)

    Kacprzak, Sylwia; Njimona, Ibrahim; Renz, Anja; Feng, Juan; Reijerse, Edward; Lubitz, Wolfgang; Krauss, Norbert; Scheerer, Patrick; Nagano, Soshichiro; Lamparter, Tilman; Weber, Stefan

    2017-05-05

    Bacterial phytochromes are dimeric light-regulated histidine kinases that convert red light into signaling events. Light absorption by the N-terminal photosensory core module (PCM) causes the proteins to switch between two spectrally distinct forms, Pr and Pfr, thus resulting in a conformational change that modulates the C-terminal histidine kinase region. To provide further insights into structural details of photoactivation, we investigated the full-length Agp1 bacteriophytochrome from the soil bacterium Agrobacterium fabrum using a combined spectroscopic and modeling approach. We generated seven mutants suitable for spin labeling to enable application of pulsed EPR techniques. The distances between attached spin labels were measured using pulsed electron-electron double resonance spectroscopy to probe the arrangement of the subunits within the dimer. We found very good agreement of experimental and calculated distances for the histidine-kinase region when both subunits are in a parallel orientation. However, experimental distance distributions surprisingly showed only limited agreement with either parallel- or antiparallel-arranged dimer structures when spin labels were placed into the PCM region. This observation indicates that the arrangements of the PCM subunits in the full-length protein dimer in solution differ significantly from that in the PCM crystals. The pulsed electron-electron double resonance data presented here revealed either no or only minor changes of distance distributions upon Pr-to-Pfr photoconversion. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. Radical-induced generation of small silver particles in SPEEK/PVA polymer films and solutions: UV-Vis, EPR, and FT-IR studies.

    Science.gov (United States)

    Korchev, A S; Konovalova, T; Cammarata, V; Kispert, L; Slaten, L; Mills, G

    2006-01-03

    The present study is centered on the processes involved in the photochemical generation of nanometer-sized Ag particles via illumination at 350 nm of aqueous solutions and cross linked films containing sulfonated poly(ether ether ketone) and poly(vinyl alcohol). Optical and electron paramagnetic resonance experiments, including electron nuclear double resonance data, proved conclusively that the photogenerated chromophore exhibiting a band with lambda(max) = 565 nm is an alpha-hydroxy aromatic (ketyl) radical of the polymeric ketone. This reducing species was produced by illumination of either solutions or films, but the radical lifetime extended from minutes in the fluid phase to hours in the solid. Direct evidence is presented that this long-lived chromophore reduces Ag(I), Cu(II), and Au(III) ions in solution. A rate constant of k = 1.4 x 10(3) M(-)(1) s(-)(1) was obtained for the reduction of Ag(+) by the ketyl radical from the post-irradiation formation of Ag crystallites. FTIR results confirmed that the photoprocess yielding polymeric ketyl radicals involves a reaction between the macromolecules. The photochemical oxidation of the polymeric alcohol, as well as the formation of light-absorbing macromolecular products and polyols, indicates that the sulfonated polyketone experienced transformations similar to those encountered during illumination of the benzophenone/2-propanol system.

  17. IR + VUV double resonance spectroscopy and extended density functional theory studies of ketone solvation by alcohol: 2-butanone·(methanol)n, n = 1-4 clusters.

    Science.gov (United States)

    Shin, Joong-Won; Bernstein, Elliot R

    2017-09-28

    Infrared plus vacuum ultraviolet (IR + VUV) photoionization vibrational spectroscopy of 2-butanone/methanol clusters [MEK·(MeOH) n , n = 1-4] is performed to explore structures associated with hydrogen bonding of MeOH molecules to the carbonyl functional group of the ketone. IR spectra and X3LYP/6-31++G(d,p) calculations show that multiple isomers of MEK·(MeOH) n are generated in the molecular beam as a result of several hydrogen bonding sites available to the clusters throughout the size range investigated. Isomer interconversion involving solvating MeOH rearrangement should probably occur for n = 1 and 2. The mode energy for a hydrogen bonded OH stretching transition gradually redshifts as the cluster size increases. Calculations suggest that the n = 3 cluster isomers adopt structures in which the MEK molecule is inserted into the cyclic MeOH hydrogen bond network. In larger structures, the cyclic network may be preserved.

  18. Conformation of L-Tyrosine Studied by Fluorescence-Detected UV-UV and IR-UV Double-Resonance Spectroscopy

    OpenAIRE

    Inokuchi, Yoshiya; Kobayashi, Yusuke; Ito, Takafumi; Ebata, Takayuki

    2007-01-01

    The laser-induced fluorescence spectrum of jet-cooled L-tyrosine exhibits more than 20 vibronic bands in the 35450-35750 cm-1 region. We attribute these bands to eight conformers by using results of UV-UV hole-burning spectroscopy. These isomers are classified into four groups; each group consists of two rotational isomers that have a similar side-chain conformation but different orientations of the phenolic OH. The splitting of band origins of rotational isomers is 31, 21, 5, and 0 cm-1 for ...

  19. A conformational study of protonated noradrenaline by UV-UV and IR dip double resonance laser spectroscopy combined with an electrospray and a cold ion trap method.

    Science.gov (United States)

    Wako, Hiromichi; Ishiuchi, Shun-Ichi; Kato, Daichi; Féraud, Géraldine; Dedonder-Lardeux, Claude; Jouvet, Christophe; Fujii, Masaaki

    2017-05-03

    The conformer-selected ultraviolet (UV) and infrared (IR) spectra of protonated noradrenaline were measured using an electrospray/cryogenic ion trap technique combined with photo-dissociation spectroscopy. By comparing the UV photo dissociation (UVPD) spectra with the UV-UV hole burning (HB) spectra, it was found that five conformers coexist under ultra-cold conditions. Based on the spectral features of the IR dip spectra of each conformer, two different conformations on the amine side chain were identified. Three conformers (group I) were assigned to folded and others (group II) to extended structures by comparing the observed IR spectra with the calculated ones. Observation of the significantly less-stable extended conformers strongly suggests that the extended structures are dominant in solution and are detected in the gas phase by kinetic trapping. The conformers in each group are assignable to rotamers of OH orientations in the catechol ring. By comparing the UV-UV HB spectra and the calculated Franck-Condon spectra obtained by harmonic vibrational analysis of the S 1 state, with the aid of relative stabilization energies of each conformer in the S 0 state, the absolute orientations of catechol OHs of the observed five conformers were successfully determined. It was found that the 0-0 transition of one folded conformer is red-shifted by about 1000 cm -1 from the others. The significant red-shift was explained by a large contribution of the πσ* state to S 1 in the conformer in which an oxygen atom of the meta-OH group is close to the ammonium group.

  20. Multitudes of Stable States in a Periodically Driven Electron-Nuclear Spin System in a Quantum Dot

    OpenAIRE

    Korenev, V. L.

    2010-01-01

    The periodical modulation of circularly polarized light with a frequency close to the electron spin resonance frequency induces a sharp change of the single electron spin orientation. Hyperfine interaction provides a feedback, thus fixing the precession frequency of the electron spin in the external and the Overhauser field near the modulation frequency. The nuclear polarization is bidirectional and the electron-nuclear spin system (ENSS) possesses a few stable states. A similar frequency-loc...

  1. Broader energy distribution of CO adsorbed at polycrystalline Pt electrode in comparison with that at Pt(111) electrode in H_2SO_4 solution confirmed by potential dependent IR/visible double resonance sum frequency generation spectroscopy

    International Nuclear Information System (INIS)

    Yang, Shuo; Noguchi, Hidenori; Uosaki, Kohei

    2017-01-01

    Highlights: • Electrochemical SFG spectroscopy is an efficient in situ probe of electronic structure at electrochemical interface. • Electrooxidation performances of CO adsorbed on polycrystalline Pt and Pt(111) electrodes were compared. • The enhanced SFG signal of CO on Pt electrodes was observed due to a vibrational-electronic double resonance effect. • The broader energy distribution of 5sa state of CO on polycrystalline Pt than on Pt(111) is proved by SFG results. - Abstract: Electrochemical cyclic voltammetry and potential dependent double resonance sum frequency generation (DR-SFG) spectroscopy were performed on CO adsorbed on polycrystalline Pt and Pt(111) electrodes in H_2SO_4 solution to examine the effect of substrate on the electronic structure of CO. The dependence of SFG intensity on potential and visible energy for atop CO band was observed on both polycrystalline and single crystalline Pt electrodes. Enhancement of the SFG intensity was determined to be a direct result of a surface electronic resonance of the visible/SF light with the electronic transition from Fermi level of Pt to the 5σ_a anti-bonding state of adsorbed CO, in agreement with previous results. Interestingly, when compared to the Pt(111) electrode, the distribution width of the intensity enhancement region on polycrystalline Pt is broader than on Pt(111). This suggests that the energy distribution of the 5σ_a state of CO on polycrystalline Pt surface is broader than that on Pt(111) due to the complex surface structure of the polycrystalline Pt electrode.

  2. Strong-Field Modulated Diffraction Effects in the Correlated Electron-Nuclear Motion in Dissociating H2+

    International Nuclear Information System (INIS)

    He Feng; Becker, Andreas; Thumm, Uwe

    2008-01-01

    We show that the electronic dynamics in a molecule driven by a strong field is complex and potentially even counterintuitive. As a prototype example, we simulate the interaction of a dissociating H 2 + molecule with an intense infrared laser pulse. Depending on the laser intensity, the direction of the electron's motion between the two nuclei is found to follow or oppose the classical laser-electric force. We explain the sensitive dependence of the correlated electronic-nuclear motion in terms of the diffracting electronic momentum distribution of the dissociating two-center system. The distribution is dynamically modulated by the nuclear motion and periodically shifted in the oscillating infrared electric field

  3. f-electron-nuclear hyperfine-coupled multiplets in the unconventional charge order phase of filled skutterudite PrRu4P12

    International Nuclear Information System (INIS)

    Aoki, Yuji; Namiki, Takahiro; Saha, Shanta R.; Sato, Hideyuki; Tayama, Takashi; Sakakibara, Toshiro; Shiina, Ryousuke; Shiba, Hiroyuki; Sugawara, Hitoshi

    2011-01-01

    The filled skutterudite PrRu 4 P 12 is known to undergo an unconventional charge order phase transition at 63 K, below which two sublattices with distinct f-electron crystalline-electric-field ground states are formed. In this paper, we study experimentally and theoretically the properties of the charge order phase at very low temperature, particularly focusing on the nature of the degenerate triplet ground state on one of the sublattices. First, we present experimental results of specific heat and magnetization measured with high quality single crystals. In spite of the absence of any symmetry breaking, the specific heat shows a peak structure at T p =0.30 K in zero field; it shifts to higher temperatures as the magnetic field is applied. In addition, the magnetization curve has a remarkable rounding below 1 T. Then, we study the origin of these experimental findings by considering the hyperfine interaction between 4f electron and nuclear spin. We demonstrate that the puzzling behaviors at low temperatures can be well accounted for by the formation of 4f-electron-nuclear hyperfine-coupled multiplets, the first thermodynamical observation of its kind. (author)

  4. Hyperfine electron-nuclear interactions in the frame of the Density Functional and of the Density Matrix Methods

    International Nuclear Information System (INIS)

    Pavlov, R.L.; Pavlov, L.I.; Raychev, P.P.; Garistov, V.P.; Dimitrova-Ivanovich, M.

    2002-01-01

    The matrix elements and expectation values of the hyperfine interaction operators are presented in a form suitable for numerical implementation in density matrix methods. The electron-nuclear spin-spin (dipolar and contact) interactions are considered, as well as the interaction between nuclear spin and electron-orbital motions. These interactions from the effective Breit-Pauli Hamiltonian determine the hyperfine structure in ESR spectra and contribute to chemical shifts in NMR. Applying the Wigner-Eckart theorem in the irreducible tensor-operator technique and the spin-space separation scheme, the matrix elements and expectation values of these relativistic corrections are expressed in analytical form. The final results are presented as products, or sums of products, of factors determined by the spin and (or) angular momentum symmetry and a spatial part determined by the action of the symmetrized tensor-operators on the normalized matrix or function of the spin or charge distribution.

  5. Double resonance spectroscopy of the D1Πu+ and B′′ B-bar 1Σu+ states near the third dissociation threshold of H2

    International Nuclear Information System (INIS)

    Ekey, R C; Cordova, A E; Duan, W; Chartrand, A M; McCormack, E F

    2013-01-01

    Double-resonance laser spectroscopy via the E,F 1 Σ g + ,v ′ =6,J ′ state was used to probe the energy region below the third dissociation limit of molecular hydrogen. Resonantly enhanced multi-photon ionization spectra were recorded by detecting ion production as a function of energy using a time-of-flight mass spectrometer. Energies and line widths for the v = 14–17 levels of the D 1 Π u + state of H 2 are reported and compared to experimental data obtained by using VUV synchrotron light excitation (Dickenson et al 2010 J. Chem. Phys. 133 144317) and fully ab initio non-adiabatic calculations of D 1 Π u + state energies and line widths (Glass-Maujean et al 2012 Phys. Rev. A 86 052507). Several high vibrational levels of the B ′′ B-bar 1 Σ u + state were also observed in this region. Term energies and rotational constants for the v = 67–69 vibrational levels are reported and compared to highly accurate ro-vibrational energy level predictions from fully ab initio non-adiabatic calculations of the first six 1 Σ u + levels of H 2 (Wolniewicz et al 2006 J. Mol. Spectrosc. 238 118). While additional observed transitions can be assigned to other states, several unassigned features in the spectra highlight the need for a fully integrated theoretical treatment of dissociation and ionization to understand the complex pattern of highly vibrationally excited states expected in this region. (paper)

  6. Generation of complete electronic nuclear medicine reports including static, dynamic and gated images

    International Nuclear Information System (INIS)

    Beretta, M.; Pilon, R.; Mut, F.

    2002-01-01

    Aim: To develop a procedure for the creation of nuclear medicine reports containing static and dynamic images. The reason for implementing this technique is the lack of adequate solutions for an electronic format of nuclear medicine results allowing for rapid transmission via e-mail, specially in the case of dynamic and gated SPECT studies, since functional data is best presented in dynamic mode. Material and Methods: Clinical images were acquired in static, whole body, dynamic and gated mode, corresponding to bone studies, diuretic renogram, radionuclide cystography and gated perfusion SPECT, as well as respective time-activity curves. Image files were imported from a dedicated nuclear medicine computer system (Elscint XPert) to a Windows-based PC through a standard ethernet network with TCP-IP communications protocol, using a software developed by us which permits the conversion from the manufacturer's original format into a bitmap format (.bmp) compatible with commercially available PC software. For cardiac perfusion studies, background was subtracted prior to transferring to reduce the amount of information in the file; this was not done for other type of studies because useful data could be eliminated. Dynamic images were then processed using commercial software to create animated files and stored in .gif format. Static images were re-sized and stored in .jpg format. Original color or gray scale was always preserved. All the graphic material was then merged with a previously prepared report text using HTML format. The report also contained reference diagrams to facilitate interpretation. The whole report was then compressed into a self-extractable file, ready to be sent by electronic mail. Reception of the material was visually checked for data integrity including image quality by two experienced nuclear medicine physicians. Results: The report presented allows for simultaneous visualization of the text, diagrams and images either static, dynamic, gated or

  7. Probing strong-field electron-nuclear dynamics of polyatomic molecules using proton motion

    International Nuclear Information System (INIS)

    Markevitch, Alexei N.; Smith, Stanley M.; Levis, Robert J.; Romanov, Dmitri A.

    2007-01-01

    Proton ejection during Coulomb explosion is studied for several structure-related organic molecules (anthracene, anthraquinone, and octahydroanthracene) subjected to 800 nm, 60 fs laser pulses at intensities from 0.50 to 4.0x10 14 W cm -2 . The proton kinetic energy distributions are found to be markedly structure specific. The distributions are bimodal for anthracene and octahydroanthracene and trimodal for anthraquinone. Maximum (cutoff) energies of the distributions range from 50 eV for anthracene to 83 eV for anthraquinone. The low-energy mode (∼10 eV) is most pronounced in octahydroanthracene. The dependence of the characteristic features of the distributions on the laser intensity provides insights into molecular specificity of such strong-field phenomena as (i) nonadiabatic charge localization and (ii) field-mediated restructuring of polyatomic molecules polarized by a strong laser field

  8. Advances in magnetic resonance 10

    CERN Document Server

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 10, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains three chapters that examine superoperators in magnetic resonance; ultrasonically modulated paramagnetic resonance; and the utility of electron paramagnetic resonance (EPR) and electron-nuclear double-resonance (ENDOR) techniques for studying low-frequency modes of atomic fluctuations and their significance for understanding the mechanism of structural phase transitions in solids.

  9. Electron paramagnetic resonance and density-functional theory studies of Cu(II)-bis(oxamato) complexes.

    Science.gov (United States)

    Bräuer, Björn; Weigend, Florian; Fittipaldi, Maria; Gatteschi, Dante; Reijerse, Edward J; Guerri, Annalisa; Ciattini, Samuele; Salvan, Georgeta; Rüffer, Tobias

    2008-08-04

    In this work we present the investigation of the influence of electronic and structural variations induced by varying the N,N'-bridge on the magnetic properties of Cu(II)- bis(oxamato) complexes. For this study the complexes [Cu(opba)] (2-) ( 1, opba = o-phenylene- bis(oxamato)), [Cu(nabo)] (2-) ( 2, nabo = 2,3-naphthalene- bis(oxamato)), [Cu(acbo)] (2-) ( 3, acbo = 2,3-anthrachinone- bis(oxamato)), [Cu(pba)] (2-) ( 4, pba = propylene- bis(oxamato)), [Cu(obbo)] (2-) ( 5, obbo = o-benzyl- bis(oxamato)), and [Cu(npbo)] (2-) ( 6, npbo = 1,8-naphthalene- bis(oxamato)), and the respective structurally isomorphic Ni(II) complexes ( 8- 13) have been prepared as ( (n)Bu 4N) (+) salts. The new complex ( (n)Bu 4N) 2[Cu(R-bnbo)].2H 2O ( 7, R-bnbo = (R)-1,1'-binaphthalene-2,2'- bis(oxamato)) was synthesized and is the first chiral complex in the series of Cu(II)-bis(oxamato) complexes. The molecular structure of 7 has been determined by single crystal X-ray analysis. The Cu(II) ions of the complexes 1- 7 are eta (4)(kappa (2) N, kappa (2) O) coordinated with a more or less distorted square planar geometry for 1- 6 and a distorted tetrahedral geometry for 7. Using pulsed Electron Nuclear Double Resonance on complex 6, detailed information about the relative orientation of the hyperfine ( A) and nuclear quadrupole tensors ( Q) of the coordinating nitrogens with respect to the g tensor were obtained. Electron Paramagnetic Resonance studies in the X, Q, and W-band at variable temperatures were carried out to extract g and A values of N ligands and Cu ion for 1- 7. The hyperfine values were interpreted in terms of spin population on the corresponding atoms. The obtained trends of the spin population for the monomeric building blocks were shown to correlate to the trends obtained in the dependence of the exchange interaction of the corresponding trinuclear complexes on their geometry.

  10. Molecular frame photoemission: a probe of electronic/nuclear photo-dynamics and polarization state of the ionizing light

    International Nuclear Information System (INIS)

    Veyrinas, Kevin

    2015-01-01

    This is thesis is dedicated to the study and the use of the remarkable properties of the molecular frame photoelectron angular distribution (MFPAD). This observable is a very sensitive probe of both the photoionization (PI) processes in small molecules, through the determination of the magnitudes and relative phases of the dipole matrix elements, and the polarization state of the ionizing light, which is entirely encoded in the MFPAD in terms of the Stokes parameters (s1, s2, s3). MFPAD measurements take advantage of dissociative photoionization (DPI) processes by combining an electron-ion 3D momentum spectroscopy technique with the use of different radiation facilities: SOLEIL synchrotron (DESIRS and PLEIADES beamlines) and the XUV PLFA beamline (SLIC, LIDyL Attophysics group, CEA Saclay) based on the interaction of a strong laser field with a gaseous target called high harmonic generation (HHG). The first part of the thesis is devoted to the complete characterization of the polarization state of an incoming radiation. In this context, an original 'molecular polarimetry' method is introduced and demonstrated by comparison with a VUV optical polarimeter available on the DESIRS beamline. Using this method to determine the full polarization ellipse of HHG radiation generated in different conditions on the XUV PLFA facility leads to original results that include the challenging disentanglement of the circular and unpolarized components of the studied radiation. The second part deals with the study of DPI of the H 2 , D 2 and HD molecules induced by circularly polarized light at resonance with the doubly excited states Q1 and Q2. In this energy region (30-35 eV) where direct ionization, autoionization and dissociation compete on a femtosecond timescale, the photonic excitation gives rise to complex ultrafast electronic and nuclear coupled dynamics. The remarkable asymmetries observed in the circular dichroism in the molecular frame, compared to quantum

  11. Detection of closed influenza virus hemagglutinin fusion peptide structures in membranes by backbone {sup 13}CO-{sup 15}N rotational-echo double-resonance solid-state NMR

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Ujjayini; Xie Li; Weliky, David P., E-mail: weliky@chemistry.msu.edu [Michigan State University, Department of Chemistry (United States)

    2013-02-15

    The influenza virus fusion peptide is the N-terminal {approx}20 residues of the HA2 subunit of the hemagglutinin protein and this peptide plays a key role in the fusion of the viral and endosomal membranes during initial infection of a cell. The fusion peptide adopts N-helix/turn/C-helix structure in both detergent and membranes with reports of both open and closed interhelical topologies. In the present study, backbone {sup 13}CO-{sup 15}N REDOR solid-state NMR was applied to the membrane-associated fusion peptide to detect the distribution of interhelical distances. The data clearly showed a large fraction of closed and semi-closed topologies and were best-fitted to a mixture of two structures that do not exchange. One of the earlier open structural models may have incorrect G13 dihedral angles derived from TALOS analysis of experimentally correct {sup 13}C shifts.

  12. Spectrometer for external detection of magnetic and related double resonance

    International Nuclear Information System (INIS)

    Sagalyn, P.L.; Alexander, M.N.

    1977-01-01

    The patent relates to an improvement in nuclear magnetic resonance spectrometer apparatus. It consists of a spectrometer which utilizes separate materials containing, respectively, sample and detector spin systems as opposed to one in which the sample and detector spins are contained in the same single material

  13. Ion cyclotron wave excitation by double resonance coupling

    International Nuclear Information System (INIS)

    Fasoli, A.; Good, T.N.; Paris, P.J.; Skiff, F.; Tran, M.Q.

    1990-07-01

    A modulated high frequency wave is used to remotely excite low frequency oscillations in a linear, strongly magnetized plasma column. An electromagnetic wave is launched as an extraordinary mode across the plasma by an external waveguide in the Upper Hybrid frequency regime f=f UH =f ce =8 GHz, with P≤2 W. By frequency modulating (at f FM =1-60 kHz, with f ci ≅30 kHz) the pump wave, the resonant layer is swept radially across the profile and perpendicularly to the field lines at f=f FM . The resulting radial oscillation of the electron linear and non linear pressure can be considered to act as a source term for the ion wave. A localized virtual antenna is thereby created inside the plasma. Measurements of the ion dielectric response (interferograms and perturbed distribution functions) via laser induced fluorescence identify the two branches (forward, or ion-acoustic-like, and backward, or Bernstein, modes) of the electrostatic dispersion relation in the ion cyclotron frequency range. By changing the modulation bandwidth, and thus the spatial excursion of the oscillating resonant layer, a control on the perpendicular wavelength of the excited mode can be exerted. In particular, the possibility of selective excitation of the ion Bernstein wave is demonstrated experimentally. (author) 38 refs., 13 figs

  14. A combined NMR and XRD study of AFI and AEL type molecular sieves

    NARCIS (Netherlands)

    Peeters, M.P.J.; Ven, van de L.J.M.; Haan, de J.W.; Hooff, van J.H.C.

    1993-01-01

    Calcined dehydrated AlPO4-5 was studied by x-ray powder diffraction, 31P MAS, and 27Al double-resonance (DOR) NMR. Three crystallog. different sites can be distinguished in the structure of dehydrated AlPO4-5 in the ratio 1:1:1. The obsd. splitting of the NMR spectra is correlated to the line width

  15. Two-frequency radiospectrometer for studying paramagnetics under a strong magnetic field

    International Nuclear Information System (INIS)

    Vertii, A.A.; Gudym, I.Y.; Ivanchenko, I.V.

    1994-01-01

    A two-frequency radiospectrometer for studying electron paramagnetic resonance in the 120-150-GHz band and nuclear magnetic resonance in the 180-200-MHz band is described. The spectrometer is used to measure the properties of paramagnetics by a double-resonance technique in a magnetic field of up to 5 T at a temperature ranging from 1.7 to 20 degrees K

  16. In honour of N. Yngve Öhrn: surveying proton cancer therapy reactions with Öhrn's electron nuclear dynamics method. Aqueous clusters radiolysis and DNA-base damage by proton collisions

    Science.gov (United States)

    Mclaurin, Patrick M.; Privett, Austin J.; Stopera, Christopher; Grimes, Thomas V.; Perera, Ajith; Morales, Jorge A.

    2015-02-01

    Proton cancer therapy (PCT) utilises high-energy H+ projectiles to cure cancer. PCT healing arises from its DNA damage in cancerous cells, which is mostly inflicted by the products from PCT water radiolysis reactions. While clinically established, a complete microscopic understanding of PCT remains elusive. To help in the microscopic elucidation of PCT, Professor Öhrn's simplest-level electron nuclear dynamics (SLEND) method is herein applied to H+ + (H2O)3-4 and H+ + DNA-bases at ELab = 1.0 keV. These are two types of computationally feasible prototypes to study water radiolysis reactions and H+-induced DNA damage, respectively. SLEND is a time-dependent, variational, non-adiabatic and direct-dynamics method that adopts a nuclear classical-mechanics description and an electronic single-determinantal wavefunction. Additionally, our SLEND + effective-core-potential method is herein employed to simulate some computationally demanding PCT reactions. Due to these attributes, SLEND proves appropriate for the simulation of various types of PCT reactions accurately and feasibly. H+ + (H2O)3-4 simulations reveal two main processes: H+ projectile scattering and the simultaneous formation of H and OH fragments; the latter process is quantified through total integrals cross sections. H+ + DNA-base simulations reveal atoms and groups displacements, ring openings and base-to-proton electron transfers as predominant damage processes. The authors warmly dedicate this SLEND investigation in honour of Professor N. Yngve Öhrn on the occasion of his 80th birthday celebration during the 54th Sanibel Symposium in St. Simons' Island, Georgia, on February 16-21, 2014. Associate Professor Jorge A. Morales was a former chemistry PhD student under the mentorship of Professor Öhrn and Dr Ajith Perera took various quantum chemistry courses taught by Professor Öhrn during his chemistry PhD studies. Both Jorge and Ajith look back to those great times of their scientific formation under

  17. Electronic structure of deep impurity centers in silicon

    International Nuclear Information System (INIS)

    Oosten, A.B. van.

    1989-01-01

    This thesis reports an experimental study of deep level impurity centers in silicon, with much attention for theoretical interpretation of the data. A detailed picture of the electronic structure of several centers was obtained by magnetic resonance techniques, such as electron paramagnetic resonance (EPR), electron-nuclear double resonance (ENDOR) and field scanned ENDOR (FSE). The thesis consists of two parts. The first part deals with chalcogen (sulfur, selenium and tellurium) related impurities, which are mostly double donors. The second part is about late transition metal (nickel, palladium and platinum) impurities, which are single (Pd,Pt) or double (Ni) acceptor centers. (author). 155 refs.; 51 figs.; 23 tabs

  18. l-Tryptophan Radical Cation Electron Spin Resonance Studies: Connecting Solution-derived Hyperfine Coupling Constants with Protein Spectral Interpretations

    Science.gov (United States)

    Connor, Henry D.; Sturgeon, Bradley E.; Mottley, Carolyn; Sipe, Herbert J.; Mason, Ronald P.

    2009-01-01

    Fast-flow electron spin resonance (ESR) spectroscopy has been used to detect a free radical formed from the reaction of l-tryptophan with Ce4+ in an acidic aqueous environment. Computer simulations of the ESR spectra from l-tryptophan and several isotopically modified forms strongly support the conclusion that the l-tryptophan radical cation has been detected by ESR for the first time. The hyperfine coupling constants (HFCs) determined from the well-resolved isotropic ESR spectra support experimental and computational efforts to understand l-tryptophan's role in protein catalysis of oxidation-reduction processes. l-tryptophan HFCs facilitated the simulation of fast-flow ESR spectra of free radicals from two related compounds, tryptamine and 3-methylindole. Analysis of these three compounds' β-methylene hydrogen HFC data along with equivalent l-tyrosine data has led to a new computational method that can distinguish between these two amino acid free radicals in proteins without dependence on isotope labeling, electron nuclear double resonance or high-field ESR. This approach also produces geometric parameters (dihedral angles for the β-methylene hydrogens) which should facilitate protein site assignment of observed l-tryptophan radicals as has been done for l-tyrosine radicals. PMID:18433127

  19. Investigation of the structure of photosynthetic reaction centers. Progress report, June 1, 1981-April 1, 1982

    International Nuclear Information System (INIS)

    van Willigen, H.

    1982-04-01

    The investigation is concerned with the application of Electron Nuclear Double Resonance (ENDOR) and Electron Nuclear Triple Resonance (TRIPLE) in the study of the photo excited triplet state of photosynthetic resonance methods hyperfine interactions between unpaired electrons and nuclear spins can be measured, giving an insight in the electronic and geometric structure of paramagnetic systems. During this initial phase of the project, research has focused on the following areas. (1) Instrumental aspects associated with the application of ENDOR and TRIPLE on the photo excited triplets randomly oriented in solid solution. (2) Exploration of the conditions required for these studies employing ground state triplet systems. (3) Study of photo excited triplet states of model systems such as naphthylene, zinc and magnesium tetraphenyl-porphyrin in polymethylmethacrylate or polycrystalline benzophenone. Progress made in these areas is discussed

  20. Studies of the fluorescent excited state of impurities in ionic crystals

    International Nuclear Information System (INIS)

    Romestain, Robert

    1972-01-01

    The author of this research thesis first presents experimental methods used in this research: principles (recall on the optical spectrum of an impurity in a solid, use of fluorescence polarization) and techniques (sample preparation, liquid helium cryostat, application of a disturbance, optical detection). Then, he reports the study of the Mn ++ ion in a tetrahedron crystalline field, the study of the Jahn Teller effect on the excited state of the F + centre in CaO, and the study by double resonance of a specific excited state of this same centre in CaO

  1. Low-temperature binding of NO adsorbed on MIL-100(Al)-A case study for the application of high resolution pulsed EPR methods and DFT calculations.

    Science.gov (United States)

    Mendt, Matthias; Barth, Benjamin; Hartmann, Martin; Pöppl, Andreas

    2017-12-14

    The low-temperature binding of nitric oxide (NO) in the metal-organic framework MIL-100(Al) has been investigated by pulsed electron nuclear double resonance and hyperfine sublevel correlation spectroscopy. Three NO adsorption species have been identified. Among them, one species has been verified experimentally to bind directly to an 27 Al atom and all its relevant 14 N and 27 Al hyperfine interaction parameters have been determined spectroscopically. Those parameters fit well to the calculated ones of a theoretical cluster model, which was derived by density functional theory (DFT) in the present work and describes the low temperature binding of NO to the regular coordinatively unsaturated Al 3+ site of the MIL-100(Al) structure. As a result, the Lewis acidity of that site has been characterized using the NO molecule as an electron paramagnetic resonance active probe. The DFT derived wave function analysis revealed a bent end-on coordination of the NO molecule adsorbed at that site which is almost purely ionic and has a weak binding energy. The calculated flat potential energy surface of this species indicates the ability of the NO molecule to freely rotate at intermediate temperatures while it is still binding to the Al 3+ site. For the other two NO adsorption species, no structural models could be derived, but one of them is indicated to be adsorbed at the organic part of the metal-organic framework. Hyperfine interactions with protons, weakly coupled to the observed NO adsorption species, have also been measured by pulsed electron paramagnetic resonance and found to be consistent with their attribution to protons of the MIL-100(Al) benzenetricarboxylate ligand molecules.

  2. Low-temperature binding of NO adsorbed on MIL-100(Al)—A case study for the application of high resolution pulsed EPR methods and DFT calculations

    Science.gov (United States)

    Mendt, Matthias; Barth, Benjamin; Hartmann, Martin; Pöppl, Andreas

    2017-12-01

    The low-temperature binding of nitric oxide (NO) in the metal-organic framework MIL-100(Al) has been investigated by pulsed electron nuclear double resonance and hyperfine sublevel correlation spectroscopy. Three NO adsorption species have been identified. Among them, one species has been verified experimentally to bind directly to an 27Al atom and all its relevant 14N and 27Al hyperfine interaction parameters have been determined spectroscopically. Those parameters fit well to the calculated ones of a theoretical cluster model, which was derived by density functional theory (DFT) in the present work and describes the low temperature binding of NO to the regular coordinatively unsaturated Al3+ site of the MIL-100(Al) structure. As a result, the Lewis acidity of that site has been characterized using the NO molecule as an electron paramagnetic resonance active probe. The DFT derived wave function analysis revealed a bent end-on coordination of the NO molecule adsorbed at that site which is almost purely ionic and has a weak binding energy. The calculated flat potential energy surface of this species indicates the ability of the NO molecule to freely rotate at intermediate temperatures while it is still binding to the Al3+ site. For the other two NO adsorption species, no structural models could be derived, but one of them is indicated to be adsorbed at the organic part of the metal-organic framework. Hyperfine interactions with protons, weakly coupled to the observed NO adsorption species, have also been measured by pulsed electron paramagnetic resonance and found to be consistent with their attribution to protons of the MIL-100(Al) benzenetricarboxylate ligand molecules.

  3. Double resonance modulation characteristics of optically injection-locked Fabry–Perot lasers

    International Nuclear Information System (INIS)

    Dorogush, E S; Afonenko, A A

    2015-01-01

    The distributed resonator model is used to show the presence of several resonance responses on the modulation characteristic of optically injection-locked Fabry–Perot lasers. The positions of the resonance peaks on the modulation characteristic are determined by the resonator length and frequency detuning of optical injection. It is shown that an appropriate choice of the resonator length and injection locking conditions allows one to obtain efficient modulation in two ranges near 40 – 60 GHz or to increase the direct modulation bandwidth up to 50 GHz. (control of laser radiation parameters)

  4. Double resonance modulation characteristics of optically injection-locked Fabry–Perot lasers

    Energy Technology Data Exchange (ETDEWEB)

    Dorogush, E S; Afonenko, A A [Belarusian State University, Minsk (Belarus)

    2015-12-31

    The distributed resonator model is used to show the presence of several resonance responses on the modulation characteristic of optically injection-locked Fabry–Perot lasers. The positions of the resonance peaks on the modulation characteristic are determined by the resonator length and frequency detuning of optical injection. It is shown that an appropriate choice of the resonator length and injection locking conditions allows one to obtain efficient modulation in two ranges near 40 – 60 GHz or to increase the direct modulation bandwidth up to 50 GHz. (control of laser radiation parameters)

  5. Microwave-optical double resonance spectroscopy. Progress report, February 1, 1976--January 31, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, D.W.

    1976-11-01

    Zero-field and high-field optical detection of magnetic resonance (ODMR), electron paramagnetic resonance (EPR), and optical spectroscopy experiments have been performed on several systems in order to further basic knowledge of the structure, reactions, and response to radiation of atoms, molecules, and ions in their ground and/or excited electronic states. Particularly noteworthy results for the present contract year include the determination of the complete magnetic and optical properties of the lowest triplet states of 1-chloro, 1-bromo, and 1-iodonaphthalene, the development of a microscopic model for the intramolecular heavy-atom effect in the /sup 3/(..pi..,..pi..*) states of aromatic molecules, a detailed analysis of the angular dependence of the hyperfine and quadrupole structure in triplet 1-bromonaphthalene, observation of proton hyperfine structure in the hf ODMR spectra of short-lived triplet states, a definitive paper on the relative importance of spin delocalization and second-order spin-orbit coupling effects in /sup 3/(n,..pi..*) benzophenone (a phototype photochemical system), a detailed analysis of the level-anticrossing spectra of several triplet state benzophenones which exhibit hyperfine structure in the cross-relaxation region (thus permitting the determination of key magnetic parameters in the complete absence of perturbing microwave or radiofrequency fields), optical detection of ground-state NQR transitions in host crystal molecules, the observation of strong radiofrequency transitions near avoided crossing points in Zeeman energy level diagrams of photoexcited triplet states, the construction of zero-field ODMR, ODENDOR, and hf ODENDOR spectrometers, measurements of the activation parameters for ring interconversions of several free radicals containing five- and six-membered rings, and experimental proof that the triplet state of trimethylenemethane (a key reactive intermediate in organic chemistry) is the ground state.

  6. Double-resonant processes in x.sup.20.sup. nonlinear periodic media

    Czech Academy of Sciences Publication Activity Database

    Konotop, V. V.; Kuzmiak, Vladimír

    2000-01-01

    Roč. 17, č. 11 (2000), s. 1874-1883 ISSN 0740-3224 Grant - others:Fundo European de Desenvolvimento Regional and Program PRAXIS XXI(PT) PRAXIS/2/2.1/FIS/176/94 Institutional research plan: CEZ:AV0Z2067918 Keywords : nonlinear media * electromagnetic wave propagation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.943, year: 2000

  7. Optical/Millimeter-Wave Double-Resonance Spectroscopy of Rydberg Atoms

    National Research Council Canada - National Science Library

    Gallagher, Thomas

    2003-01-01

    AFOSR grant F49620-03-1-0287 is a DUlUP grant providing laser and millimeter wave instrumentation for the AFOSR sponsored research programs of Robert Jones and Thomas Gallagher at the University of Virginia...

  8. Theory of strongly saturated double-resonance line shapes in arbitrary angular momentum states of molecules

    International Nuclear Information System (INIS)

    Galbraith, H.W.; Dubs, M.; Steinfeld, J.I.

    1982-01-01

    We calculate the steady-state probe absorption line-shape function for a strongly driven, Zeeman-degenerate molecular system. The probe laser is treated to lowest order while the pump laser is dealt with to all orders. We obtain the probe line shape for the cases of parallel and perpendicular linear polarization of the two lasers. As expected, the effects of M degeneracy, as well as differences due to the relative laser polarizations, are most pronounced when Doppler broadening is not important. However, even in the presence of large Doppler broadening we find a narrowing of the population hole by including the Zeeman degeneracy and a further narrowing if perpendicular laser polarizations are used

  9. Structural, theoretical and experimental models of photosynthetic antennas, donors and acceptors

    International Nuclear Information System (INIS)

    Barkigia, K.M.; Chantranupong, L.; Fajer, J.; Kehres, L.A.; Smith, K.M.

    1989-01-01

    Theoretical calculations, based on recent x-ray studies of bacterial reaction centers, suggest that the light-absorption properties of the special pair phototraps in bacteria are controlled by the interplanar spacing between the bacteriochlorophyll subunits that constitute the special pairs. The calculations offer attractively simple explanations for the range of absorption spectra exhibited by photosynthetic bacteria. The wide range of (bacterio)chlorophyll skeletal conformations revealed by x-ray diffraction studies raise the intriguing possibility that different conformations, imposed by protein constraints, can modulate the light-absorption and redox properties of the chromophores in vivo. Electron-nuclear double resonance data obtained for the primary acceptors in green plants suggest specific substituent orientations and hydrogen bonding that may help optimize the orientations of the acceptors relative to the donors

  10. Magnetic resonance of semiconductors and their nanostructures basic and advanced applications

    CERN Document Server

    Baranov, Pavel G; Jelezko, Fedor; Wrachtrup, Jörg

    2017-01-01

    This book explains different magnetic resonance (MR) techniques and uses different combinations of these techniques to analyze defects in semiconductors and nanostructures. It also introduces novelties such as single defects MR and electron-paramagnetic-resonance-based methods: electron spin echo, electrically detected magnetic resonance, optically detected magnetic resonance and electron-nuclear double resonance – the designated tools for investigating the structural and spin properties of condensed systems, living matter, nanostructures and nanobiotechnology objects. Further, the authors address problems existing in semiconductor and nanotechnology sciences that can be resolved using MR, and discuss past, current and future applications of MR, with a focus on advances in MR methods. The book is intended for researchers in MR studies of semiconductors and nanostructures wanting a comprehensive review of what has been done in their own and related fields of study, as well as future perspectives.

  11. Chemical Structure of Insoluble Organic Matter of Meteorites

    Science.gov (United States)

    Derenne, S.; Robert, F.; Binet, L.; Gourier, D.; Rouzaud, J.-N.; Largeau, C.

    A detailed knowledge of the insoluble organic matter (IOM) of the meteorites is essential to estimate to what extent the interstellar organic matter was preserved during the formation of the solar system and to decipher the synthetic pathways of this matter in space. Although predominant, the insoluble organic fraction has been much less extensively studied than soluble one due to specific analytical difficulties. The present work reports the examination of the IOM of two carbonaceous meteorites, Orgueil and Murchison through a number of various spectroscopic and microscopic methods, i. e. XANES for sulphur, carbon and nitrogen, solid state 13C NMR, electron paramagnetic resonance, electron nuclear double resonance and high resolution transmission electron microscopy.

  12. Delocalization of Coherent Triplet Excitons in Linear Rigid Rod Conjugated Oligomers.

    Science.gov (United States)

    Hintze, Christian; Korf, Patrick; Degen, Frank; Schütze, Friederike; Mecking, Stefan; Steiner, Ulrich E; Drescher, Malte

    2017-02-02

    In this work, the triplet state delocalization in a series of monodisperse oligo(p-phenyleneethynylene)s (OPEs) is studied by pulsed electron paramagnetic resonance (EPR) and pulsed electron nuclear double resonance (ENDOR) determining zero-field splitting, optical spin polarization, and proton hyperfine couplings. Neither the zero-field splitting parameters nor the optical spin polarization change significantly with OPE chain length, in contrast to the hyperfine coupling constants, which showed a systematic decrease with chain length n according to a 2/(1 + n) decay law. The results provide striking evidence for the Frenkel-type nature of the triplet excitons exhibiting full coherent delocalization in the OPEs under investigation with up to five OPE repeat units and with a spin density distribution described by a nodeless particle in the box wave function. The same model is successfully applied to recently published data on π-conjugated porphyrin oligomers.

  13. Conformational analysis of quinine and its pseudo enantiomer quinidine: a combined jet-cooled spectroscopy and vibrational circular dichroism study.

    Science.gov (United States)

    Sen, Ananya; Bouchet, Aude; Lepère, Valeria; Le Barbu-Debus, Katia; Scuderi, D; Piuzzi, F; Zehnacker-Rentien, A

    2012-08-16

    Laser-desorbed quinine and quinidine have been studied in the gas phase by combining supersonic expansion with laser spectroscopy, namely, laser-induced fluorescence (LIF), resonance-enhanced multiphoton ionization (REMPI), and IR-UV double resonance experiments. Density funtional theory (DFT) calculations have been done in conjunction with the experimental work. The first electronic transition of quinine and quinidine is of π-π* nature, and the studied molecules weakly fluoresce in the gas phase, in contrast to what was observed in solution (Qin, W. W.; et al. J. Phys. Chem. C2009, 113, 11790). The two pseudo enantiomers quinine and quinidine show limited differences in the gas phase; their main conformation is of open type as it is in solution. However, vibrational circular dichroism (VCD) experiments in solution show that additional conformers exist in condensed phase for quinidine, which are not observed for quinine. This difference in behavior between the two pseudo enantiomers is discussed.

  14. Scaling laws in high energy electron-nuclear processes

    International Nuclear Information System (INIS)

    Chemtob, M.

    1980-11-01

    We survey the parton model description of high momentum transfer electron scattering processes with nuclei. We discuss both nucleon and quark parton models and confront the patterns of scaling laws violations, induced by binding effects, in the former, and perturbative QCD effects, in the latter

  15. Double resonance long period fiber grating for detection of E. coli in trace concentration by choosing a proper bacteriophage

    Science.gov (United States)

    Chiniforooshan, Y.; Celebanska, A.; Janik, M.; Mikulic, P.; Haddad, F.; Perreault, J.; Bock, W. J.

    2017-04-01

    There is a critical need of a fast, specific and reliable assay for biological species. To address this need, long period fiber gratings (LPFG) among other fiber optic sensors can be used because of their high sensitivity to changes in surrounding medium. In this work we fabricated and used two over-etched LPFGs. One of them was covered with T4 Phage and the other was covered with MS2 phage that both specifically bind with Escherichia coli (E. coli) bacteria. This bacterium is a major cause of the food contaminations and outbreaks. We showed achieving a highest sensitivity region of the LPFG and the way to fine tune to that region by over-etching the grating. Finally, using the highly sensitive LPFG platform we could detect E. coli at concentrations as low as 100 colony forming units (CFU), by covering the LPFG with an optimized bio-functionalization of the fiber surface with MS2 bacteriophage.

  16. IR-UV double resonance spectroscopic investigation of phenylacetylene-alcohol complexes. Alkyl group induced hydrogen bond switching.

    Science.gov (United States)

    Singh, Prashant Chandra; Patwari, G Naresh

    2008-06-12

    The electronic transitions of phenylacetylene complexes with water and trifluoroethanol are shifted to the blue, while the corresponding transitions for methanol and ethanol complexes are shifted to the red relative to the phenylacetylene monomer. Fluorescence dip infrared (FDIR) spectra in the O-H stretching region indicate that, in all the cases, phenylacetylene is acting as a hydrogen bond acceptor to the alcohols. The FDIR spectrum in the acetylenic C-H stretching region shows Fermi resonance bands for the bare phenylacetylene, which act as a sensitive tool to probe the intermolecular structures. The FDIR spectra reveal that water and trifluoroethanol interact with the pi electron density of the acetylene C-C triple bond, while methanol and ethanol interact with the pi electron density of the benzene ring. It can be inferred that the hydrogen bonding acceptor site on phenylacetylene switches from the acetylene pi to the benzene pi with lowering in the partial charge on the hydrogen atom of the OH group. The most significant finding is that the intermolecular structures of water and methanol complexes are notably distinct, which, to the best of our knowledge, this is first such observation in the case of complexes of substituted benzenes.

  17. The double-resonance enhancement of stimulated low-frequency Raman scattering in silver-capped nanodiamonds

    Science.gov (United States)

    Baranov, A. N.; Butsen, A. V.; Ionin, A. A.; Ivanova, A. K.; Kuchmizhak, A. A.; Kudryashov, S. I.; Kudryavtseva, A. D.; Levchenko, A. O.; Rudenko, A. A.; Saraeva, I. N.; Strokov, M. A.; Tcherniega, N. V.; Zayarny, D. A.

    2017-09-01

    Hybrid plasmonic-dielectric nano- and (sub)microparticles exhibit magnetic and electrical dipolar Mie-resonances, which makes them useful as efficient basic elements in surface-enhanced spectroscopy, non-linear light conversion and nanoscale light control. We report the stimulated low-frequency Raman scattering (SLFRS) of a nanosecond ruby laser radiation (central wavelength λ = 694.3 nm (full-width at half-maximum ≈ 0.015 cm-1), gaussian 1/e-intensity pulsewidth τ ≈ 20 ns, TEM00-mode pulse energy Emax ≈ 0.3 J) in nanodiamond (R ≈ 120 nm) hydrosols, induced via optomechanical coherent excitation of fundamental breathing eigen-modes, and the two-fold enhancement of SLFRS in Ag-decorated nanodiamonds, characterized by hybrid dipolar resonances of electrical (silver) and magnetic (diamond) nature. Hybrid metal-dielectric particles were prepared by means of nanosecond IR-laser ablation of solid silver target in diamond hydrosols with consecutive Ag-capping of diamonds, and were characterized by scanning electron microscopy, UV-vis, photoluminescence and energy-dispersive X-ray spectroscopy. Intensities of the SLFR-scattered components and their size-dependent spectral shifts were measured in the highly sensitive stimulated scattering regime, indicating the high (≈ 30%) SLFRS conversion efficiency and the resonant character of the scattering species.

  18. Water speciation in sodium silicate glasses (quenched melts): A comprehensive NMR study

    Science.gov (United States)

    Xue, X.; Kanzaki, M.; Eguchi, J.

    2012-12-01

    Dissolution mechanism of water is an important factor governing how the dissolved water affects the physical and thermodynamic properties of silicate melts and glasses. Our previous studies have demonstrated that 1H MAS NMR in combination with 29Si-1H and 27Al-1H double-resonance NMR experiments is an effective approach for unambiguously differentiating and quantifying different water species in quenched silicate melts (glasses). Several contrasting dissolution mechanisms have been revealed depending on the melt composition: for relatively polymerized melts, the formation of SiOH/AlOH species (plus molecular H2O) and depolymerization of the network structure dominate; whereas for depolymerized Ca-Mg silicate melts, free OH (e.g. MgOH) become increasingly important (cf. [1]). The proportion of free OH species has been shown to decrease with both increasing melt polymerization (silica content) and decreasing field strength of the network modifying cations (from Mg to Ca). Our previous 1H and 29Si MAS NMR results for hydrous Na silicate glasses of limited compositions (Na2Si4O9 and Na2Si2O5) were consistent with negligible free OH (NaOH) species and depolymerizing effect of water dissolution [2]. On the other hand, there were also other studies that proposed the presence of significant NaOH species in hydrous glasses near the Na2Si2O5 composition. The purpose of this study is apply the approach of combined 1H MAS NMR and double-resonance (29Si-1H and 23Na-1H) NMR to gain unambiguous evidence for the OH speciation in Na silicate glasses (melts) as a function of composition. Hydrous Na silicate glasses containing mostly ≤ 1 wt% H2O for a range of Na/Si ratios from 0.33 to 1.33 have been synthesized by rapidly quenching melts either at 0.2 GPa using an internally heated gas pressure vessel or at 1 GPa using a piston cylinder high-pressure apparatus. NMR spectra have been acquired using a 9.4 T Varian Unity-Inova spectrometer. The 29Si and 1H chemical shifts are

  19. NMR studies of the solution conformation and dynamics of the tyrocidine peptide antibiotics

    International Nuclear Information System (INIS)

    Zhou, N.

    1985-01-01

    The tyrocidine B and tyrocidine C 1 H NMR spectra in DMSO-d 6 were assigned by using 2D 1 H- 1 H correlation spectroscopy and 1D double resonance experiments. Based on the proton chemical shifts, 3 J/sub NH-Nα/ coupling constants, the chemical shift temperature dependence, and 1D and 2D 1 H- 1 H NOE values, a backbone conformation consisting of an anti-parallel β-pleated sheet, a type I β-turn and a type II' β-turn was suggested for both tyrocidines B and C. Seven out of ten side chains were determined to exist predominantly in one classical Chi 1 rotamer; while the residues Val 1 and Leu 3 had two Chi 1 rotamers which were significantly populated. Chi 2 angles were determined for residues Phe 4 , Trp 6 , DPhe 7 (D Trp 7 ) and Asn 8 . The natural abundance 13 C spectra of tyrocidine B and tyrocidine C were assigned by using 1 H- 13 C correlation spectroscopy. A study of the effect of soluble paramagnetic nitroxide compounds on tyrocidine A proton T 1 values were performed which confirmed the proposed tyrocidine A conformation. It also proved that these nitroxide compounds are very useful in studying proton solvent exposure, and therefore in delineating hydrogen bonding. A proton NMR study of the opioid peptide dynorphin-(1-13) in aqueous solution was reported which was consistent with a non-ordered molecule in the solution

  20. The development of high-resolution spectroscopic methods and their use in atomic structure studies

    International Nuclear Information System (INIS)

    Poulsen, O.

    1984-01-01

    This thesis discusses work performed during the last nine years in the field of atomic spectroscopy. Several high-resolution techniques, ranging from quantum beats, level crossings, rf-laser double resonances to nonlinear field atom interactions, have been employed. In particular, these methods have been adopted and developed to deal with fast accelerated atomic or ionic beams, allowing studies of problems in atomic-structure theory. Fine- and hyperfine-structure determinations in the He I and Li I isoelectronic sequences, in 51 V I, and in 235 U I, II have permitted a detailed comparison with ab initio calculations, demonstrating the change in problems when going towards heavier elements or higher ionization stage. The last part of the thesis is concerned with the fundamental question of obtaining very high optical resolution in the interaction between a fast accelerated atom or ion beam and a laser field, this problem being the core in the continuing development of atomic spectroscopy necessary to challenge the more precise and sophisticated theories advanced. (Auth.)

  1. Monte-Carlo study of ICRF-sustained mode operation in tandem mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Todd, A.M.M. (Grumman Aerospace Corp., Princeton, NJ (USA))

    1984-09-01

    A study, using a Monte-Carlo simulation code, of ICRF-sustained mode operation in tandem mirrors by way of ICRF end-cell fuelling and heating is described. Although the basic parameter space considered corresponds to the Phaedrus experiment, the central-cell density and temperatures are extended towards the reactor regime. It is found that significant end cell ion potential barriers can be generated with ICRF, but that, owing to choking of the central-cell ion source stream by the plugging potential, saturation occurs and power requirements rapidly increase, so that the potential rise is limited to about twice the central-cell ion temperature. Although performance is improved as the ion cyclotron resonance approaches the end-cell mid-plane, no significant difference is found between inboard, outboard or double resonance location. As the central-cell density and temperatures are increased, the RF power requirement is found to increase dramatically. Optimum performance for end cell fuelling results when the central-cell electron temperature is higher than the ion temperature, but the magnitude of this ratio is limited by an increase in threshold power level with electron temperature.

  2. Pulsed-High Field/High-Frequency EPR Spectroscopy

    Science.gov (United States)

    Fuhs, Michael; Moebius, Klaus

    Pulsed high-field/high-frequency electron paramagnetic resonance (EPR) spectroscopy is used to disentangle many kinds of different effects often obscured in continuous wave (cw) EPR spectra at lower magnetic fields/microwave frequencies. While the high magnetic field increases the resolution of G tensors and of nuclear Larmor frequencies, the high frequencies allow for higher time resolution for molecular dynamics as well as for transient paramagnetic intermediates studied with time-resolved EPR. Pulsed EPR methods are used for example for relaxation-time studies, and pulsed Electron Nuclear DOuble Resonance (ENDOR) is used to resolve unresolved hyperfine structure hidden in inhomogeneous linewidths. In the present article we introduce the basic concepts and selected applications to structure and mobility studies on electron transfer systems, reaction centers of photosynthesis as well as biomimetic models. The article concludes with an introduction to stochastic EPR which makes use of an other concept for investigating resonance systems in order to increase the excitation bandwidth of pulsed EPR. The limited excitation bandwidth of pulses at high frequency is one of the main limitations which, so far, made Fourier transform methods hardly feasible.

  3. In Quest of the Alanine R3 Radical: Multivariate EPR Spectral Analyses of X-Irradiated Alanine in the Solid State.

    Science.gov (United States)

    Jåstad, Eirik O; Torheim, Turid; Villeneuve, Kathleen M; Kvaal, Knut; Hole, Eli O; Sagstuen, Einar; Malinen, Eirik; Futsaether, Cecilia M

    2017-09-28

    The amino acid l-α-alanine is the most commonly used material for solid-state electron paramagnetic resonance (EPR) dosimetry, due to the formation of highly stable radicals upon irradiation, with yields proportional to the radiation dose. Two major alanine radical components designated R1 and R2 have previously been uniquely characterized from EPR and electron-nuclear double resonance (ENDOR) studies as well as from quantum chemical calculations. There is also convincing experimental evidence of a third minor radical component R3, and a tentative radical structure has been suggested, even though no well-defined spectral signature has been observed experimentally. In the present study, temperature dependent EPR spectra of X-ray irradiated polycrystalline alanine were analyzed using five multivariate methods in further attempts to understand the composite nature of the alanine dosimeter EPR spectrum. Principal component analysis (PCA), maximum likelihood common factor analysis (MLCFA), independent component analysis (ICA), self-modeling mixture analysis (SMA), and multivariate curve resolution (MCR) were used to extract pure radical spectra and their fractional contributions from the experimental EPR spectra. All methods yielded spectral estimates resembling the established R1 spectrum. Furthermore, SMA and MCR consistently predicted both the established R2 spectrum and the shape of the R3 spectrum. The predicted shape of the R3 spectrum corresponded well with the proposed tentative spectrum derived from spectrum simulations. Thus, results from two independent multivariate data analysis techniques strongly support the previous evidence that three radicals are indeed present in irradiated alanine samples.

  4. ENDOR-Induced EPR of Disordered Systems: Application to X-Irradiated Alanine.

    Science.gov (United States)

    Kusakovskij, Jevgenij; Maes, Kwinten; Callens, Freddy; Vrielinck, Henk

    2018-02-15

    The electron paramagnetic resonance (EPR) spectra of radiation-induced radicals in organic solids are generally composed of multiple components that largely overlap due to their similar weak g anisotropy and a large number of hyperfine (HF) interactions. Such properties make these systems difficult to study using standard cw EPR spectroscopy even in single crystals. Electron-nuclear double-resonance (ENDOR) spectroscopy is a powerful and widely used complementary technique. In particular, ENDOR-induced EPR (EIE) experiments are useful for separating the overlapping contributions. In the present work, these techniques were employed to study the EPR spectrum of stable radicals in X-irradiated alanine, which is widely used in dosimetric applications. The principal values of all major proton HF interactions of the dominant radicals were determined by analyzing the magnetic field dependence of the ENDOR spectrum at 50 K, where the rotation of methyl groups is frozen. Accurate simulations of the EPR spectrum were performed after the major components were separated using an EIE analysis. As a result, new evidence in favor of the model of the second dominant radical was obtained.

  5. X-ray Crystallographic, Multifrequency Electron Paramagnetic Resonance, and Density Functional Theory Characterization of the Ni(P(Cy)2N(tBu)2)2(n+) Hydrogen Oxidation Catalyst in the Ni(I) Oxidation State.

    Science.gov (United States)

    Niklas, Jens; Westwood, Mark; Mardis, Kristy L; Brown, Tiara L; Pitts-McCoy, Anthony M; Hopkins, Michael D; Poluektov, Oleg G

    2015-07-06

    The Ni(I) hydrogen oxidation catalyst [Ni(P(Cy)2N(tBu)2)2](+) (1(+); P(Cy)2N(tBu)2 = 1,5-di(tert-butyl)-3,7-dicyclohexyl-1,5-diaza-3,7-diphosphacyclooctane) has been studied using a combination of electron paramagnetic resonance (EPR) techniques (X-, Q-, and D-band, electron-nuclear double resonance, hyperfine sublevel correlation spectroscopy), X-ray crystallography, and density functional theory (DFT) calculations. Crystallographic and DFT studies indicate that the molecular structure of 1(+) is highly symmetrical. EPR spectroscopy has allowed determination of the electronic g tensor and the spin density distribution on the ligands, and revealed that the Ni(I) center does not interact strongly with the potentially coordinating solvents acetonitrile and butyronitrile. The EPR spectra and magnetic parameters of 1(+) are found to be distinctly different from those for the related compound [Ni(P(Ph)2N(Ph)2)2](+) (4(+)). One significant contributor to these differences is that the molecular structure of 4(+) is unsymmetrical, unlike that of 1(+). DFT calculations on derivatives in which the R and R' groups are systematically varied have allowed elucidation of structure/substituent relationships and their corresponding influence on the magnetic resonance parameters.

  6. Contribution to the study, by magnetic resonance, of the properties of heavily doped silicon at low temperature

    International Nuclear Information System (INIS)

    Jerome, D.

    1965-10-01

    The magnetic properties of heavily doped silicon at low temperature have been studied in a range of concentration on either side of the Mott transition. For impurity densities less than that of the transition a magnetic double resonance method allows the exchange coupling between localized donors to be measured, and in addition the existence of paramagnetic centers (pairs of neutral and ionized donors) is demonstrated. The behaviour of the spin-lattice relaxation of 29 Ci is explained in terms of the dipolar coupling between nuclei and paramagnetic centers. In the range of concentration 10 16 -10 17 impurities/cm 3 , the concentration dependent relaxation of donors is studied experimentally. A theoretical explanation is proposed for the latter mechanism, the basis of which is the presence of ionized pairs of donors. At increasing impurity concentrations the electronic delocalization increases. For the concentration of 2.5 X 10 18 P/cm 3 the hyperfine coupling is responsible for the 29 Si relaxation. It is shown that the electron density has a very large maximum near the impurities in the metallic domain of concentrations. An estimation of the impurity band width (19 deg. K) is deduced from the measurement of the paramagnetic part of the electronic susceptibility at low temperature. (author) [fr

  7. New developments in high field electron paramagnetic resonance with applications in structural biology

    International Nuclear Information System (INIS)

    Bennati, Marina; Prisner, Thomas F

    2005-01-01

    Recent developments in microwave technologies have led to a renaissance of electron paramagnetic resonance (EPR) due to the implementation of new spectrometers operating at frequencies ≥90 GHz. EPR at high fields and high frequencies (HF-EPR) has been established up to THz (very high frequency (VHF) EPR) in continuous wave (cw) operation and up to about 300 GHz in pulsed operation. To date, its most prominent application field is structural biology. This review article first gives an overview of the theoretical basics and the technical aspects of HF-EPR methodologies, such as cw and pulsed HF-EPR, as well as electron nuclear double resonance at high fields (HF-ENDOR). In the second part, the article illustrates different application areas of HF-EPR in studies of protein structure and function. In particular, HF-EPR has delivered essential contributions to disentangling complex spectra of radical cofactors or reaction intermediates in photosynthetic reaction centres, radical enzymes (such as ribonucleotide reductase) and in metalloproteins. Furthermore, HF-EPR combined with site-directed spin labelling in membranes and soluble proteins provides new methods of investigating complex molecular dynamics and intermolecular distances

  8. Hyperfine structure of the MnH X 7Sigma + state: A large gas-to-matrix shift in the Fermi contact interaction

    Science.gov (United States)

    Varberg, Thomas D.; Field, Robert W.; Merer, Anthony J.

    1990-06-01

    Sub-Doppler spectra of the A 7Π-X 7Σ+ (0,0) band of gas phase MnH near 5680 Å were recorded by intermodulated fluorescence spectroscopy. The spectra reveal hyperfine splittings arising from both the 55Mn and 1H nuclear spins. Internal hyperfine perturbations have been observed between the different spin components of the ground state at low N`. From a preliminary analysis of several rotational lines originating from the isolated and unperturbed F1(J`=3) spin component of the X 7Σ+(N`=0) level, the 55Mn Fermi contact interaction in the ground state has been measured as bF=Aiso =276(1) MHz. This value is 11% smaller than the value obtained by Weltner et al. from an electron-nuclear double resonance (ENDOR) study of MnH in an argon matrix at 4 K. This unprecedented gas-to-matrix shift in the Fermi contact parameter is discussed.

  9. Hyperfine structure of the MnH X 7Σ+ state: A large gas-to-matrix shift in the Fermi contact interaction

    International Nuclear Information System (INIS)

    Varberg, T.D.; Field, R.W.; Merer, A.J.

    1990-01-01

    Sub-Doppler spectra of the A 7 Π--X 7 Σ + (0,0) band of gas phase MnH near 5680 A were recorded by intermodulated fluorescence spectroscopy. The spectra reveal hyperfine splittings arising from both the 55 Mn and 1 H nuclear spins. Internal hyperfine perturbations have been observed between the different spin components of the ground state at low N double-prime. From a preliminary analysis of several rotational lines originating from the isolated and unperturbed F 1 (J double-prime=3) spin component of the X 7 Σ + (N double-prime=0) level, the 55 Mn Fermi contact interaction in the ground state has been measured as b F =A iso =276(1) MHz. This value is 11% smaller than the value obtained by Weltner et al. from an electron-nuclear double resonance (ENDOR) study of MnH in an argon matrix at 4 K. This unprecedented gas-to-matrix shift in the Fermi contact parameter is discussed

  10. Investigation of the Copper Binding Site And the Role of Histidine As a Ligand in Riboflavin Binding Protein

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S.R.; Bencze, K.Z.; Russ, K.A.; Wasiukanis, K.; Benore-Parsons, M.; Stemmler, T.L.

    2009-05-26

    Riboflavin Binding Protein (RBP) binds copper in a 1:1 molar ratio, forming a distinct well-ordered type II site. The nature of this site has been examined using X-ray absorption and pulsed electron paramagnetic resonance (EPR) spectroscopies, revealing a four coordinate oxygen/nitrogen rich environment. On the basis of analysis of the Cambridge Structural Database, the average protein bound copper-ligand bond length of 1.96 {angstrom}, obtained by extended x-ray absorption fine structure (EXAFS), is consistent with four coordinate Cu(I) and Cu(II) models that utilize mixed oxygen and nitrogen ligand distributions. These data suggest a Cu-O{sub 3}N coordination state for copper bound to RBP. While pulsed EPR studies including hyperfine sublevel correlation spectroscopy and electron nuclear double resonance show clear spectroscopic evidence for a histidine bound to the copper, inclusion of a histidine in the EXAFS simulation did not lead to any significant improvement in the fit.

  11. Fluorescent scattering by molecules embedded in small particles

    International Nuclear Information System (INIS)

    1982-01-01

    Studies are reported in these areas: double resonance in fluorescent and Raman scattering; surface enhanced Raman scattering; fluorescence by molecules embedded in small particles; fluorescence by a liquid droplet; and fluorescence by conical pits in surfaces

  12. Investigation of magnetic interactions in sulfides by means of magnetic resonance

    International Nuclear Information System (INIS)

    Veen, G. van.

    1978-01-01

    Investigations have been designed to gather more information about magnetic pair interactions in sulfides by isomorphic substitution of the magnetic ions in suitable chosen diamagnetic host lattices and measurement of electron spin resonance of coupled pairs and of electron spin resonance or electron nuclear double resonance of the hyperfine interaction due to the nuclei of diamagnetic cations. The greater part of this thesis is devoted to preliminaries of magnetic resonance interpretation and sample selection and preparation. The measurements on the magnetically diluted compounds, which are described, only have an exploratory nature. (Auth.)

  13. High-precision, systematic study of hyperfine structure in the 4f/sup N/6s2 configuration of the neutral rare earths

    International Nuclear Information System (INIS)

    Childs, W.J.; Goodman, L.S.; Pfeufer, V.

    1983-01-01

    Although the hyperfine structure (hfs) of many-electron atoms has been studied intensively in recent years, it is still difficult to distinguish between the competing effects of relativity and configuration interaction. The 4f/sup N/6s 2 configuration of the neutral rare earths is of particular interest because (a) the low-lying terms are relatively free of configuration interaction, and (b) trends can be examined systematically as one proceeds through the long 4f-shell. The procedure is to deduce, from the measured hfs constants of low levels, the underlying hyperfine radial integrals for comparison with ab initio predictions. Since some of these integrals are extremely sensitive to any configuration interaction and others are not, it is possible to determine both the extent and type of configuration interaction present in some cases. Prior to the start of the present research no precise hfs information existed for the entire second half of the 4f shell of the rare earths. The present measurements were designed both to provide such data and to make possible a systematic study of the hfs throughout the 4f shell. The atomic-beam, laser-rf, double-resonance method was used for the measurements. With this technique, the occurrence of a radiofrequency transition between atomic hfs levels is detected by noting an increase in the laser-induced fluorescence

  14. Magnetic pseudo-fields in a rotating electron-nuclear spin system

    Science.gov (United States)

    Wood, A. A.; Lilette, E.; Fein, Y. Y.; Perunicic, V. S.; Hollenberg, L. C. L.; Scholten, R. E.; Martin, A. M.

    2017-11-01

    Analogous to the precession of a Foucault pendulum observed on the rotating Earth, a precessing spin observed in a rotating frame of reference appears frequency-shifted. This can be understood as arising from a magnetic pseudo-field in the rotating frame that nevertheless has physically significant consequences, such as the Barnett effect. To detect these pseudo-fields, a rotating-frame sensor is required. Here we use quantum sensors, nitrogen-vacancy (NV) centres, in a rapidly rotating diamond to detect pseudo-fields in the rotating frame. Whereas conventional magnetic fields induce precession at a rate proportional to the gyromagnetic ratio, rotation shifts the precession of all spins equally, and thus primarily affect 13C nuclear spins in the sample. We are thus able to explore these effects via quantum sensing in a rapidly rotating frame, and define a new approach to quantum control using rotationally induced nuclear spin-selective magnetic fields. This work provides an integral step towards realizing precision rotation sensing and quantum spin gyroscopes.

  15. Electron-Nuclear Energy Sharing in Above-Threshold Multiphoton Dissociative Ionization of H2

    DEFF Research Database (Denmark)

    Wu, J.; Kunitski, M.; Pitzer, M.

    2013-01-01

    We report experimental observation of the energy sharing between electron and nuclei in above-threshold multiphoton dissociative ionization of H2 by strong laser fields. The absorbed photon energy is shared between the ejected electron and nuclei in a correlated fashion, resulting in multiple...... diagonal lines in their joint energy spectrum governed by the energy conservation of all fragment particles....

  16. Electron-nuclear interaction in 13C nanotube double quantum dots

    DEFF Research Database (Denmark)

    Churchill, H O H; Bestwick, A J; Harlow, J W

    2009-01-01

    For coherent electron spins, hyperfine coupling to nuclei in the host material can either be a dominant source of unwanted spin decoherence or, if controlled effectively, a resource enabling storage and retrieval of quantum information. To investigate the effect of a controllable nuclear...... environment on the evolution of confined electron spins, we have fabricated and measured gate-defined double quantum dots with integrated charge sensors made from single-walled carbon nanotubes with a variable concentration of 13C (nuclear spin I=1/2) among the majority zero-nuclear-spin 12C atoms. We observe...... strong isotope effects in spin-blockaded transport, and from the magnetic field dependence estimate the hyperfine coupling in 13C nanotubes to be of the order of 100 ¿µeV, two orders of magnitude larger than anticipated. 13C-enhanced nanotubes are an interesting system for spin-based quantum information...

  17. Electron-nuclear. gamma. transition spectrum of a nucleus in a multicharged atomic ion

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, L N; Letokhov, V S

    1987-08-01

    The nuclear emission of absorption spectrum of an atom possesses a set of electron satelites which are due to an alternation of the state of the electron shell. It is shown that the mechanism of formation of the satellites might be different for neutral atoms and high-charge ions. In the first case (loose electron shell) a ''shaking'' of the shell resulting from the interaction between the nucleus and ..gamma.. quantum is predominant. In the second case (rigid electron shell) the mechanism involves a direct interaction between the ..gamma.. quantum and electrons. The second mechanism is important in the case of dipole nuclear transitions and dominates at ..gamma.. quantum energies

  18. Establishing and Advancing Electronic Nuclear Material Accounting Capabilities: A Canadian Perspective

    International Nuclear Information System (INIS)

    Sample, J.

    2015-01-01

    Under safeguards agreements that the Government of Canada has with the International Atomic Energy Agency (IAEA), and nuclear cooperation agreements with other states, the Canadian Nuclear Safety Commission (CNSC) is required to track the inventory and movement of all safeguarded material. As safeguards programmes evolve, including the implementation of Integrated Safeguards, the scope of the reporting requirements for facilities within Canada has also increased. At the same time, ensuring the secure transmission of the associated data continues to be an overarching factor. The changes that are occurring in the nuclear material accounting (NMA) landscape have necessitated a modernization of Canada's accounting and reporting system, with the objective of creating a more effective and efficient system, while at the same time maintaining the security of prescribed information. After a review of the environment, the CNSC embarked on a project that would encourage facilities to transition away from traditional modes of NMA reporting and adopt an electronic approach. This paper will discuss how the changes to Canada's NMA infrastructure were identified and implemented internally to allow for optimized electronic reporting. Improvements included the development of the regulatory and guidance documents, the overhaul of the reporting forms, the upgrade of the CNSC's NMA database, and the development of an electronic reporting platform that leveraged existing technologies. The paper will also discuss the logistics of engaging stakeholders throughout the process, launching the system and soliciting feedback for future system improvements. Special consideration will be given to the benefits realized by both the CNSC and facilities who have voluntarily embraced electronic reporting. The final objective of this paper will be to identify the challenges that were faced by the CNSC and the nuclear industry as the system changes were implemented and to highlight how these obstacles were overcome or will be addressed. (author)

  19. Electron-nuclear γ transition spectrum of a nucleus in a multicharged atomic ion

    International Nuclear Information System (INIS)

    Ivanov, L.N.; Letokhov, V.S.

    1987-01-01

    The nuclear emission of absorption spectrum of an atom possesses a set of electron satelites which are due to an alternation of the state of the electron shell. It is shown that the mechanism of formation of the satellites might be different for neutral atoms and high-charge ions. In the first case (loose electron shell) a ''shaking'' of the shell resulting from the interaction between the nucleus and γ quantum is predominant. In the second case (rigid electron shell) the mechanism involves a direct interaction between the γ quantum and electrons. The second mechanism is important in the case of dipole nuclear transitions and dominates at γ quantum energies p 2λ (λ is the nuclear transition multipole order, μ p ∼ 1/2 π is the relative proton mass and z the core mass). In the spectrum of the plasma source the electron satellites corresponding to the γ quantum emission and absorption lines are not overlapped by the Doppler contour of the γ line

  20. High-field EPR on membrane proteins - crossing the gap to NMR.

    Science.gov (United States)

    Möbius, Klaus; Lubitz, Wolfgang; Savitsky, Anton

    2013-11-01

    In this review on advanced EPR spectroscopy, which addresses both the EPR and NMR communities, considerable emphasis is put on delineating the complementarity of NMR and EPR concerning the measurement of molecular interactions in large biomolecules. From these interactions, detailed information can be revealed on structure and dynamics of macromolecules embedded in solution- or solid-state environments. New developments in pulsed microwave and sweepable cryomagnet technology as well as ultrafast electronics for signal data handling and processing have pushed to new horizons the limits of EPR spectroscopy and its multifrequency extensions concerning the sensitivity of detection, the selectivity with respect to interactions, and the resolution in frequency and time domains. One of the most important advances has been the extension of EPR to high magnetic fields and microwave frequencies, very much in analogy to what happens in NMR. This is exemplified by referring to ongoing efforts for signal enhancement in both NMR and EPR double-resonance techniques by exploiting dynamic nuclear or electron spin polarization via unpaired electron spins and their electron-nuclear or electron-electron interactions. Signal and resolution enhancements are particularly spectacular for double-resonance techniques such as ENDOR and PELDOR at high magnetic fields. They provide greatly improved orientational selection for disordered samples that approaches single-crystal resolution at canonical g-tensor orientations - even for molecules with small g-anisotropies. Exchange of experience between the EPR and NMR communities allows for handling polarization and resolution improvement strategies in an optimal manner. Consequently, a dramatic improvement of EPR detection sensitivity could be achieved, even for short-lived paramagnetic reaction intermediates. Unique structural and dynamic information is thus revealed that can hardly be obtained by any other analytical techniques. Micromolar

  1. NMR/NQR study of the superconductor Y2Ba4Cu7O15

    International Nuclear Information System (INIS)

    Stern, R.

    1995-01-01

    This dissertation concentrates on several important aspects of the high temperature superconductivity research. Nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) studies in Y-Ba-O compounds contribute information regarding various aspects, ranging from the direct observation of strong coupling between the adjacent planes in the double plane to conclusions concerning the spatial symmetry of paring state in these cuprates. We report the first results in the 93 K superconductor Y 2 Ba 4 Cu 7 O 15 . This compound turns out to be a structure containing differently doped CuO 2 planes. The planes in the 1-2-3(1-2-4) block are only slightly lower (higher) doped than those in the corresponding parent compounds YBa 2 Cu 3 O 7 and YBa 2 Cu 4 O 8 . The results obtained from measurements on oxygen depleted Y 2 Ba 4 Cu 7 O 15-x show two new features which could explain the dissimilar variation of T c with oxygen content compared to YBa 2 Cu 3 O 7-x : i) the double chains donate charge carriers to the planes and ii) the chain fragments which survive when emptying single chains are longer than in YBa 2 Cu 3 O 7-x . The pressure induced charge transfer from chain to plane in each block of Y 2 Ba 4 Cu 7 O 15 is the same as in the corresponding parent compound. We explore the strong coupling between nonequivalent planes in this compound using the three main NMR/NQR quantities, K spin , 1/T 1 ; and T 2G,ind , and estimate its approximate strength directly from spin-echo double resonance (SEDOR) experiments. We obtain for the ratio of the effective inter- and intraplane exchange-coupling constants the value of 0.3 just above T c . This ratio decreases with increasing temperature. (author) figs., tabs., refs

  2. Study

    Directory of Open Access Journals (Sweden)

    Erum Zahir

    2017-05-01

    Full Text Available Physicochemical properties like density, viscosity, boiling point, saponification value (SV, iodine value (IV,and peroxide value (PV of Corn and Mustard oils were studied to evaluate the compositional quality of oils and also to investigate the effect on the use of same oil for repeated frying as it ultimately changes the physicochemical, nutritional and sensory properties of the oil. FT-IR spectroscopy was used to evaluate the degree of oxidation after heating and frying processes. Results revealed that due to the temperature change in the oil there is a notable difference in the spectral band which showed that the proportions of the fatty acids were changed. The spectra of Corn oil at the boiling point and at multiple frying times with a piece of potato showed frequencies in range of 2852.7–2926.0 cm−1 while in Mustard oil an additional peak was observed at 3633.8 cm−1 which exhibits the secondary oxidized product formation.

  3. Understanding the dosimetric powder EPR spectrum of sucrose by identification of the stable radiation-induced radicals

    International Nuclear Information System (INIS)

    Vrielinck, H.; Vanhaelewyn, G.; Matthys, P.; Callens, F.; Kusakovskij, J.

    2014-01-01

    Sucrose, the main component of table sugar, present in nearly every household and quite radiation sensitive, is considered as an interesting emergency dosemeter. Another application of radiation-induced radicals in sugars is the detection of irradiation in sugar-containing foodstuffs. The complexity of electron paramagnetic resonance (EPR) spectra of radicals in these materials, as a result of many hyperfine interactions and the multi-compositeness of the spectra of individual sugars, complicate dose assessment and the improvement of protocols for control and identification of irradiated sugar-containing foodstuffs using EPR. A thorough understanding of the EPR spectrum of individual irradiated sugars is desirable when one wants to reliably use them in a wide variety of dosimetric applications. Recently, the dominant room temperature stable radicals in irradiated sucrose have been thoroughly characterised using EPR, electron nuclear double resonance (ENDOR) and ENDOR-induced EPR. These radicals were structurally identified by comparing their proton hyperfine and g-tensors with the results of Density Functional Theory calculations for test radical structures. In this paper, the authors use the spin Hamiltonian parameters determined in these studies to simulate powder EPR spectra at the standard X-band (9.5 GHz), commonly used in applications, and at higher frequencies, up to J-band (285 GHz), rendering spectra with higher resolution. A few pitfalls in the simulation process are highlighted. The results indicate that the major part of the dosimetric spectrum can be understood in terms of three dominant radicals, but as-yet unidentified radicals also contribute in a non-negligible way. (authors)

  4. Monovalent Cation Activation of the Radical SAM Enzyme Pyruvate Formate-Lyase Activating Enzyme.

    Science.gov (United States)

    Shisler, Krista A; Hutcheson, Rachel U; Horitani, Masaki; Duschene, Kaitlin S; Crain, Adam V; Byer, Amanda S; Shepard, Eric M; Rasmussen, Ashley; Yang, Jian; Broderick, William E; Vey, Jessica L; Drennan, Catherine L; Hoffman, Brian M; Broderick, Joan B

    2017-08-30

    Pyruvate formate-lyase activating enzyme (PFL-AE) is a radical S-adenosyl-l-methionine (SAM) enzyme that installs a catalytically essential glycyl radical on pyruvate formate-lyase. We show that PFL-AE binds a catalytically essential monovalent cation at its active site, yet another parallel with B 12 enzymes, and we characterize this cation site by a combination of structural, biochemical, and spectroscopic approaches. Refinement of the PFL-AE crystal structure reveals Na + as the most likely ion present in the solved structures, and pulsed electron nuclear double resonance (ENDOR) demonstrates that the same cation site is occupied by 23 Na in the solution state of the as-isolated enzyme. A SAM carboxylate-oxygen is an M + ligand, and EPR and circular dichroism spectroscopies reveal that both the site occupancy and the identity of the cation perturb the electronic properties of the SAM-chelated iron-sulfur cluster. ENDOR studies of the PFL-AE/[ 13 C-methyl]-SAM complex show that the target sulfonium positioning varies with the cation, while the observation of an isotropic hyperfine coupling to the cation by ENDOR measurements establishes its intimate, SAM-mediated interaction with the cluster. This monovalent cation site controls enzyme activity: (i) PFL-AE in the absence of any simple monovalent cations has little-no activity; and (ii) among monocations, going down Group 1 of the periodic table from Li + to Cs + , PFL-AE activity sharply maximizes at K + , with NH 4 + closely matching the efficacy of K + . PFL-AE is thus a type I M + -activated enzyme whose M + controls reactivity by interactions with the cosubstrate, SAM, which is bound to the catalytic iron-sulfur cluster.

  5. Time-dependent view of an isotope effect in electron-nuclear nonequilibrium dynamics with applications to N2.

    Science.gov (United States)

    Ajay, Jayanth S; Komarova, Ksenia G; Remacle, Francoise; Levine, R D

    2018-05-21

    Isotopic fractionation in the photodissociation of N 2 could explain the considerable variation in the 14 N/ 15 N ratio in different regions of our galaxy. We previously proposed that such an isotope effect is due to coupling of photoexcited bound valence and Rydberg electronic states in the frequency range where there is strong state mixing. We here identify features of the role of the mass in the dynamics through a time-dependent quantum-mechanical simulation. The photoexcitation of N 2 is by an ultrashort pulse so that the process has a sharply defined origin in time and so that we can monitor the isolated molecule dynamics in time. An ultrafast pulse is necessarily broad in frequency and spans several excited electronic states. Each excited molecule is therefore not in a given electronic state but in a superposition state. A short time after excitation, there is a fairly sharp onset of a mass-dependent large population transfer when wave packets on two different electronic states in the same molecule overlap. This coherent overlap of the wave packets on different electronic states in the region of strong coupling allows an effective transfer of population that is very mass dependent. The extent of the transfer depends on the product of the populations on the two different electronic states and on their relative phase. It is as if two molecules collide but the process occurs within one molecule, a molecule that is simultaneously in both states. An analytical toy model recovers the (strong) mass and energy dependence.

  6. Laser Spectroscopic and Theoretical Studies of Encapsulation Complexes of Calix[4]arene

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, Shohei; Inokuchi, Yoshiya; Ebata, Takayuki; Apra, Edoardo; Xantheas, Sotiris S.

    2011-10-13

    The complexes between the host calix[4]arene (C4A) and various guest molecules such as NH3, N2, CH4, and C2H2 have been investigated via experimental and theoretical methods. The S1-S0 electronic spectra of these guest-host complexes are observed by mass-selected resonant two-photon ionization (R2PI) and laser induced fluorescence (LIF) spectroscopy. The infrared (IR) spectra of the complexes formed in molecular beams are obtained by IR-UV double resonance (IR-UV DR) and IR photodissociation (IRPD) spectroscopy. The supramolecular structures of the complexes are investigated by electronic structure methods (density functional and second order perturbation theory). The current results for the various molecular guests are put in perspective with the previously reported ones for the C4A-Rare Gas (Rg) (Phys. Chem. Chem. Phys. 2007, 126, 141101) and C4A-H2O complexes (J. Phys. Chem. A, 2010, 114, 2967). The electronic spectra of the complexes of C4A with N2, CH4 and C2H2 exhibit red-shifts of similar magnitudes with the ones observed for the C4A-Rg complexes, whereas the complexes of C4A with H2O and NH3 show much larger red-shifts. Most of the IR-UV DR spectra of the complexes, except for C4A-C2H2, show a broad hydrogen bonded OH stretching band with a peak at ~3160 cm-1. The analysis of the experimental results, in agreement with the ones resulted from the electronic structure calculations, suggest that C4A preferentially forms endo-complexes with all the guest species reported in this study. We discuss the similarities and differences of the structures, binding energies and the nature of the interaction between the C4A host and the various guest species. This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy

  7. Experimental study of a high-current FEM with a broadband microwave system

    Energy Technology Data Exchange (ETDEWEB)

    Denisov, G.G.; Bratman, V.L.; Ginzburg, N.S. [Institute of Applied Physics, Nizhny Novgorod (Russian Federation)] [and others

    1995-12-31

    One of the main features of FELs and FEMs is the possibility of fast and wideband tuning of the resonant frequency of active media, which can be provided by changing the particle energy. For a frequency adjustable FEM-oscillator, a broadband microwave system, which is simply combined with an electron-optical FEM system and consists of an oversized waveguide and reflectors based on the microwave beams multiplication effect has been proposed and studied successfully in {open_quotes}cold{close_quotes} measurements. Here, the operating ability of a cavity, that includes some key elements of the broadband microwave system, was tested in the presence of an electron beam. To provide large particle oscillation velocities in a moderate undulator field and the presence of a guide magnetic field, the FEM operating regime of double resonance was chosen. In this regime the cyclotron as well as undulator resonance conditions were satisfied. The FEM-oscillator was investigated experimentally on a high-current accelerator {open_quotes}Sinus-6{close_quotes} that forms an electron beam with particle energy 500keV and pulse duration 25ns. The aperture with a diameter 2.5mm at the center of the anode allows to pass through only the central fraction of the electron beam with a current about 100A and a small spread of longitudinal velocities of the particles. Operating transverse velocity was pumped into the electron beam in the pulse plane undulator of a 2.4cm period. The cavity with a frequency near 45GHz consists of a square waveguide and two reflectors. The broadband up-stream reflector based on the multiplication effect had the power reflectivity coefficient more than 90% in the frequency band 10% for the H{sup 10} wave of the square waveguide with the maximum about 100% at a frequency 45GHz. The down-stream narrow-band Bragg reflector had the power reflection coefficient approximately 80% in the frequency band of 4% near 45GHz for the operating mode.

  8. Impact of morphology on polaron delocalization in a semicrystalline conjugated polymer

    KAUST Repository

    Steyrleuthner, Robert

    2016-12-20

    We investigate the delocalization of holes in the semicrystalline conjugated polymer poly(2,5-bis(3-alkylthiophene-2-yl)thieno[3,2-b]thiophene) (PBTTT) by directly measuring the hyperfine coupling between photogenerated polarons and bound nuclear spins using electron nuclear double resonance spectroscopy. An extrapolation of the corresponding oligomer spectra reveals that charges tend to delocalize over 4.0-4.8 nm with delocalization strongly dependent on molecular order and crystallinity of the PBTTT polymer thin films. Density functional theory calculations of hyperfine couplings confirm that long-range corrected functionals appropriately describe the change in coupling strength with increasing oligomer size and agree well with the experimentally measured polymer limit. Our discussion presents general guidelines illustrating the various pitfalls and opportunities when deducing polaron localization lengths from hyperfine coupling spectra of conjugated polymers.

  9. Molecular and applied modulation effects in electron-electron double resonance. 7. Modulation frequency effects for the CH/sub 2/COO/sup -/ radical in irradiated zinc acetate

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, Jr, R C; Dalton, L R [Vanderbilt Univ., Nashville, Tenn. (USA). Dept. of Chemistry; Kispert, L D

    1977-04-01

    Frequency-swept absorption ELDOR signals for the CH/sub 2/COO/sup -/radical in zinc acetate depend upon Zeeman modulation frequency, the signals going from a positive to a negative sense as the Zeeman modulation frequency is varied from 100 to 1 kHz. A mathematical formulation derived explicitly considering applied electromagnetic radiation and Zeeman modulation fields is employed to computer-simulate the experimentally observed effects.

  10. Residue-specific membrane location of peptides and proteins using specifically and extensively deuterated lipids and {sup 13}C-{sup 2}H rotational-echo double-resonance solid-state NMR

    Energy Technology Data Exchange (ETDEWEB)

    Xie Li; Ghosh, Ujjayini; Schmick, Scott D.; Weliky, David P., E-mail: weliky@chemistry.msu.edu [Michigan State University, Department of Chemistry (United States)

    2013-01-15

    Residue-specific location of peptides in the hydrophobic core of membranes was examined using {sup 13}C-{sup 2}H REDOR and samples in which the lipids were selectively deuterated. The transmembrane topology of the KALP peptide was validated with this approach with substantial dephasing observed for deuteration in the bilayer center and reduced or no dephasing for deuteration closer to the headgroups. Insertion of {beta} sheet HIV and helical and {beta} sheet influenza virus fusion peptides into the hydrophobic core of the membrane was validated in samples with extensively deuterated lipids.

  11. Isolated Gramicidin Peptides Probed by IR Spectroscopy

    NARCIS (Netherlands)

    Rijs, A. M.; Kabelac, M.; Abo-Riziq, A.; Hobza, P.; de Vries, M. S.

    2011-01-01

    We report double-resonant IR/UV ion-dip spectroscopy of neutral gramicidin peptides in the gas phase. The IR spectra of gramicidin A and C, recorded in both the 1000 cm(-1) to 1800 cm(-1) and the 2700 to 3750 cm(-1) region, allow structural analysis. By studying this broad IR range, various local

  12. Selective stimulation of conformational conversions in free molecules

    International Nuclear Information System (INIS)

    Ismailzade, G.I.; Movsumov, I.Z.; Menzeleev, M.R.; Kazymova, S.B.

    2014-01-01

    Application of double-resonance (RF-MW, IR-MW, MW-MW) methods to enhance studies of unstable isomeric structures was discussed. The use of infrared pump radiation to excite conformational energy levels in order to stimulate selectively conformational conversions and to correct spectral line intensities of separate conformations was substantiated. (authors)

  13. Isotopic studies of trans- and cis-HOCO using rotational spectroscopy: Formation, chemical bonding, and molecular structures

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, Michael C., E-mail: mccarthy@cfa.harvard.edu; Martinez, Oscar; Crabtree, Kyle N.; Martin-Drumel, Marie-Aline [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA and School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138 (United States); McGuire, Brett A. [National Radio Astronomy Observatory, Charlottesville, Virginia 22901 (United States); Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA and School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138 (United States); Stanton, John F. [Department of Chemistry and Biochemistry, The University of Texas at Austin, 1 University Station A5300, Austin, Texas 78712-0165 (United States)

    2016-03-28

    HOCO is an important intermediate in combustion and atmospheric processes because the OH + CO → H + CO{sub 2} reaction represents the final step for the production of CO{sub 2} in hydrocarbon oxidation, and theoretical studies predict that this reaction proceeds via various intermediates, the most important being this radical. Isotopic investigations of trans- and cis-HOCO have been undertaken using Fourier transform microwave spectroscopy and millimeter-wave double resonance techniques in combination with a supersonic molecular beam discharge source to better understand the formation, chemical bonding, and molecular structures of this radical pair. We find that trans-HOCO can be produced almost equally well from either OH + CO or H + CO{sub 2} in our discharge source, but cis-HOCO appears to be roughly two times more abundant when starting from H + CO{sub 2}. Using isotopically labelled precursors, the OH + C{sup 18}O reaction predominately yields HOC{sup 18}O for both isomers, but H{sup 18}OCO is observed as well, typically at the level of 10%-20% that of HOC{sup 18}O; the opposite propensity is found for the {sup 18}OH + CO reaction. DO + C{sup 18}O yields similar ratios between DOC{sup 18}O and D{sup 18}OCO as those found for OH + C{sup 18}O, suggesting that some fraction of HOCO (or DOCO) may be formed from the back-reaction H + CO{sub 2}, which, at the high pressure of our gas expansion, can readily occur. The large {sup 13}C Fermi-contact term (a{sub F}) for trans- and cis-HO{sup 13}CO implicates significant unpaired electronic density in a σ-type orbital at the carbon atom, in good agreement with theoretical predictions. By correcting the experimental rotational constants for zero-point vibration motion calculated theoretically using second-order vibrational perturbation theory, precise geometrical structures have been derived for both isomers.

  14. Probing Nuclear Spin Effects on Electronic Spin Coherence via EPR Measurements of Vanadium(IV) Complexes.

    Science.gov (United States)

    Graham, Michael J; Krzyaniak, Matthew D; Wasielewski, Michael R; Freedman, Danna E

    2017-07-17

    Quantum information processing (QIP) has the potential to transform numerous fields from cryptography, to finance, to the simulation of quantum systems. A promising implementation of QIP employs unpaired electronic spins as qubits, the fundamental units of information. Though molecular electronic spins offer many advantages, including chemical tunability and facile addressability, the development of design principles for the synthesis of complexes that exhibit long qubit superposition lifetimes (also known as coherence times, or T 2 ) remains a challenge. As nuclear spins in the local qubit environment are a primary cause of shortened superposition lifetimes, we recently conducted a study which employed a modular spin-free ligand scaffold to place a spin-laden propyl moiety at a series of fixed distances from an S = 1 / 2 vanadium(IV) ion in a series of vanadyl complexes. We found that, within a radius of 4.0(4)-6.6(6) Å from the metal center, nuclei did not contribute to decoherence. To assess the generality of this important design principle and test its efficacy in a different coordination geometry, we synthesized and investigated three vanadium tris(dithiolene) complexes with the same ligand set employed in our previous study: K 2 [V(C 5 H 6 S 4 ) 3 ] (1), K 2 [V(C 7 H 6 S 6 ) 3 ] (2), and K 2 [V(C 9 H 6 S 8 ) 3 ] (3). We specifically interrogated solutions of these complexes in DMF-d 7 /toluene-d 8 with pulsed electron paramagnetic resonance spectroscopy and electron nuclear double resonance spectroscopy and found that the distance dependence present in the previously synthesized vanadyl complexes holds true in this series. We further examined the coherence properties of the series in a different solvent, MeCN-d 3 /toluene-d 8 , and found that an additional property, the charge density of the complex, also affects decoherence across the series. These results highlight a previously unknown design principle for augmenting T 2 and open new pathways for the

  15. Double giant resonances in time-dependent relativistic mean-field theory

    International Nuclear Information System (INIS)

    Ring, P.; Podobnik, B.

    1996-01-01

    Collective vibrations in spherical nuclei are described in the framework of time-dependent relativistic mean-field theory (RMFT). Isoscalar quadrupole and isovector dipole oscillations that correspond to giant resonances are studied, and possible excitations of higher modes are investigated. We find evidence for modes which can be interpreted as double resonances. In a quantized RMFT they correspond to two-phonon states. (orig.)

  16. Photoionization and cold collision studies using trapped atoms

    International Nuclear Information System (INIS)

    Gould, P.L.

    1996-01-01

    The authors have used laser cooling and trapping techniques to investigate photoionization and cold collisions. With laser-trapped Rb, they have measured the photoionization cross section from the first excited (5P) level by observing the photoionization-induced loss rate of neutral atoms from the trap. This technique has the advantage that it directly measures the photoionization rate per atom. Knowing the ionizing laser intensity and the excited-state fraction, the measured loss rate gives the absolute cross section. Using this technique, the Rb 5P photoionization cross section at ∼400 nm has been determined with an uncertainty of 9%. The authors are currently attempting to extend this method to the 5D level. Using time-ordered pulses of diode-laser light (similar to the STIRAP technique), they have performed very efficient two-photon excitation of trapped Rb atoms to 5D. Finally, they will present results from a recent collaboration which combines measurements form conventional molecular spectroscopy (single photon and double resonance) with photoassociation collisions of ultracold Na atoms to yield a precise (≤1 ppm) value for the dissociation energy of the X Σ g+ ground state of the Na 2 molecule

  17. Reaction of cyanide with cytochrome ba3 from Thermus thermophilus: spectroscopic characterization of the Fe(II)a3-CN.Cu(II)B-CN complex suggests four 14N atoms are coordinated to CuB.

    Science.gov (United States)

    Surerus, K K; Oertling, W A; Fan, C; Gurbiel, R J; Einarsdóttir, O; Antholine, W E; Dyer, R B; Hoffman, B M; Woodruff, W H; Fee, J A

    1992-01-01

    Cytochrome ba3 from Thermus thermophilus reacts slowly with excess HCN at pH 7.4 to create a form of the enzyme in which CuA, cytochrome b, and CuB remain oxidized, while cytochrome a3 is reduced by one electron, presumably with the formation of cyanogen. We have examined this form of the enzyme by UV-visible, resonance Raman, EPR, and electron nuclear double resonance spectroscopies in conjunction with permutations of 13C- and 15N-labeled cyanide. The results support a model in which one CN- binds through the carbon atom to ferrous a3, supporting a low-spin (S = 0) configuration on the Fe; bridging by this cyanide to the CuB is weak or absent. Four 14N atoms, presumably donated by histidine residues of the protein, provide a strong equatorial ligand field about CuB; a second CN- is coordinated through the carbon atom to CuB in an axial position. PMID:1314380

  18. How Formaldehyde Inhibits Hydrogen Evolution by [FeFe]-Hydrogenases: Determination by ¹³C ENDOR of Direct Fe-C Coordination and Order of Electron and Proton Transfers.

    Science.gov (United States)

    Bachmeier, Andreas; Esselborn, Julian; Hexter, Suzannah V; Krämer, Tobias; Klein, Kathrin; Happe, Thomas; McGrady, John E; Myers, William K; Armstrong, Fraser A

    2015-04-29

    Formaldehyde (HCHO), a strong electrophile and a rapid and reversible inhibitor of hydrogen production by [FeFe]-hydrogenases, is used to identify the point in the catalytic cycle at which a highly reactive metal-hydrido species is formed. Investigations of the reaction of Chlamydomonas reinhardtii [FeFe]-hydrogenase with formaldehyde using pulsed-EPR techniques including electron-nuclear double resonance spectroscopy establish that formaldehyde binds close to the active site. Density functional theory calculations support an inhibited super-reduced state having a short Fe-(13)C bond in the 2Fe subsite. The adduct forms when HCHO is available to compete with H(+) transfer to a vacant, nucleophilic Fe site: had H(+) transfer already occurred, the reaction of HCHO with the Fe-hydrido species would lead to methanol, release of which is not detected. Instead, Fe-bound formaldehyde is a metal-hydrido mimic, a locked, inhibited form analogous to that in which two electrons and only one proton have transferred to the H-cluster. The results provide strong support for a mechanism in which the fastest pathway for H2 evolution involves two consecutive proton transfer steps to the H-cluster following transfer of a second electron to the active site.

  19. Solid state radiation chemistry of the DNA backbone

    International Nuclear Information System (INIS)

    Bernhard, W.A.

    1989-09-01

    The long term goal of this program is to determine the fundamental rules needed to predict the type and yield of damage produced in DNA due to direct effects of ionizing radiation. The focus is on damage to the sugar-phosphate backbone, damage that would lead to strand breaks. Model systems have been chosen that permit various aspects of this problem to be investigated. The emphasis will be on single crystals of monosaccharides, nucleosides, and nucleotides but will also include some powder work on polynucleotides. In these model systems, free radical products and reactions are observed by electron spin resonance (ESR) and electron nuclear double resonance (ENDOR) techniques. The information thus gained is used in constructing rules that predict what primary free radicals are formed in single crystals of model compounds and the reactions stemming from the primary radicals. The formulation of a set of rules that work in model systems will represent a major advance toward formulating a set of rules that predict the direct damage in DNA itself. In a broader context this program is part of the effort to understand and predict the effects of exposure to ionizing radiation received at low dose rates over long periods of time. Assessment of low dose effects requires a basic understanding of the action of radiation at the molecular level. By contributing to that basic understanding, this program will help solve the problems of risk assessment under low dose conditions. 5 refs., 3 figs

  20. Electron-mediating Cu(A) centers in proteins

    DEFF Research Database (Denmark)

    Epel, Boris; Slutter, Claire S; Neese, Frank

    2002-01-01

    High field (W-band, 95 GHz) pulsed electron-nuclear double resonance (ENDOR) measurements were carried out on a number of proteins that contain the mixed-valence, binuclear electron-mediating Cu(A) center. These include nitrous oxide reductase (N(2)OR), the recombinant water-soluble fragment...... of subunit II of Thermus thermophilus cytochrome c oxidase (COX) ba(3) (M160T9), its M160QT0 mutant, where the weak axial methionine ligand has been replaced by a glutamine, and the engineered "purple" azurin (purpAz). The three-dimensional (3-D) structures of these proteins, apart from the mutant, are known...... indicates differences in the positions of the imidazole rings relative to the Cu(2)S(2) core. Comparison of the spectral features of the weakly coupled protons of M160QT0 with those of the other investigated proteins shows that they are very similar to those of purpAz, where the Cu(A) center is the most...

  1. EPR analysis of cyanide complexes of wild-type human neuroglobin and mutants in comparison to horse heart myoglobin.

    Science.gov (United States)

    Van Doorslaer, Sabine; Trandafir, Florin; Harmer, Jeffrey R; Moens, Luc; Dewilde, Sylvia

    2014-06-01

    Electron paramagnetic resonance (EPR) data reveal large differences between the ferric ((13)C-)cyanide complexes of wild-type human neuroglobin (NGB) and its H64Q and F28L point mutants and the cyanide complexes of mammalian myo- and haemoglobin. The point mutations, which involve residues comprising the distal haem pocket in NGB, induce smaller, but still significant changes, related to changes in the stabilization of the cyanide ligand. Furthermore, for the first time, the full (13)C hyperfine tensor of the cyanide carbon of cyanide-ligated horse heart myoglobin (hhMb) was determined using Davies ENDOR (electron nuclear double resonance). Disagreement of these experimental data with earlier predictions based on (13)C NMR data and a theoretical model reveal significant flaws in the model assumptions. The same ENDOR procedure allowed also partial determination of the corresponding (13)C hyperfine tensor of cyanide-ligated NGB and H64QNGB. These (13)C parameters differ significantly from those of cyanide-ligated hhMb and challenge our current theoretical understanding of how the haem environment influences the magnetic parameters obtained by EPR and NMR in cyanide-ligated haem proteins. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. High-precision laser and rf spectroscopy of atomic, molecular, and slow ion beams

    International Nuclear Information System (INIS)

    Childs, W.J.; Steimle, T.C.; Sen, A.; Azuma, Y.

    1988-01-01

    We have obtained extensive new structural information on the light diatomic radical ScO since the last report in this series. The new studies complete our systematic investigation of the fine and hyperfine structure (hfs) of the group IIIa monoxides LaO, YO, and ScO. The studies of the molecular X 2 Σ + electronic ground state were carried out using the molecular-beam laser-rf double-resonance method, and the excited electronic state information was obtained by complementing this data with Doppler-free laser fluorescence studies

  3. A study of nuclear relaxation to the electron non-Zeeman system

    International Nuclear Information System (INIS)

    Honten, J. van.

    1979-01-01

    An examination of the nuclear spin-lattice relaxation mechanism in a series of diluted copper-caesium Tutton salt crystals, containing different percentages of D 2 O in the waters of hydration, is described. Results of relaxation measurements are presented and a strong angular dependence is observed. It is proved, however, that under most experimental conditions applied, the bottleneck in the relaxation path is not the cross-relaxation but the thermal contact between the proton Zeeman system and the electron dipole-dipole interaction system. Hence the proton spin-lattice relaxation measurements have enabled determination of the time constant of this thermal contact. The microscopic coupling process which provides thermal contact, is a simultaneous transition of two electron spins and one proton spin. This so-called three-spin transition is described and calculations presented. Double resonance experiments are performed, where the resonance signal of deuterium or caesium spins is saturated and the effect on the proton resonance signal observed. (C.F.)

  4. Excited-state molecular photoionization dynamics

    International Nuclear Information System (INIS)

    Pratt, S.T.

    1995-01-01

    This review presents a survey of work using resonance-enhanced multiphoton ionization and double-resonance techniques to study excited-state photoionization dynamics in molecules. These techniques routinely provide detail and precision that are difficult to achieve in single-photon ionization from the ground state. The review not only emphasizes new aspects of photoionization revealed in the excited-state experiments but also shows how the excited-state techniques can provide textbook illustrations of some fundamental mechanisms in molecular photoionization dynamics. Most of the examples are confined to diatomic molecules. (author)

  5. Room-temperature coupling between electrical current and nuclear spins in OLEDs

    Science.gov (United States)

    Malissa, H.; Kavand, M.; Waters, D. P.; van Schooten, K. J.; Burn, P. L.; Vardeny, Z. V.; Saam, B.; Lupton, J. M.; Boehme, C.

    2014-09-01

    The effects of external magnetic fields on the electrical conductivity of organic semiconductors have been attributed to hyperfine coupling of the spins of the charge carriers and hydrogen nuclei. We studied this coupling directly by implementation of pulsed electrically detected nuclear magnetic resonance spectroscopy in organic light-emitting diodes (OLEDs). The data revealed a fingerprint of the isotope (protium or deuterium) involved in the coherent spin precession observed in spin-echo envelope modulation. Furthermore, resonant control of the electric current by nuclear spin orientation was achieved with radiofrequency pulses in a double-resonance scheme, implying current control on energy scales one-millionth the magnitude of the thermal energy.

  6. EPR dating CO2- sites in tooth enamel apatites by ENDOR and triple resonance

    International Nuclear Information System (INIS)

    Vugman, N.V.; Rigby, S.E.J.

    1995-01-01

    In this work we combine electron paramagnetic resonance (EPR), high-resolution electron nucleus double resonance (ENDOR) and general triple resonance (GTR) spectroscopies, to study the local environment of the CO 2 - groups created by ionizing radiation in fossil tooth enamel. We demonstrate that the CO 2 - groups occupy slightly modified phosphate sites in the hydroxyapatite lattice. In quaternary shark enamel we found these groups to be interacting with water molecules in the apatite channels. The absence of water molecules as first neighbours in mammalian samples indicate, however, that these molecules are not significantly responsible for the stabilization of CO 2 - dating centers in enamel. (author)

  7. Energetic, spectral, and temporal characteristics of a two-wave CO/sub 2/ laser

    Energy Technology Data Exchange (ETDEWEB)

    Bertel' , I.M.; Petukhov, V.O.; Prokopov, A.P.; Tochitskii, S.Ya.; Churakov, V.V.

    1987-09-01

    This work studies the energetic and temporal parameters of a pulsed two-wave TEA CO/sub 2/ laser's radiation and the means for controlling these parameters. Obtaining the two-wave generation regime in CO/sub 2/ lasers uses, as is known, spatial splitting of the radiation, different variants of operating diffraction gratings, and placing a cell with selectively absorbing gas in the resonator. To realize the simultaneous two-wave generation regime in the present work, a double-resonant scheme is used with mutually orthogonal polarizers to spatially separate the radiation.

  8. Critical opalescence in the pure Coulomb system

    Energy Technology Data Exchange (ETDEWEB)

    Bobrov, V.B., E-mail: vic5907@mail.r [Joint Institute for High Temperatures, Russian Academy of Sciences, Izhorskaia St., 13, Bd. 2. Moscow 125412 (Russian Federation); Trigger, S.A., E-mail: satron@mail.r [Joint Institute for High Temperatures, Russian Academy of Sciences, Izhorskaia St., 13, Bd. 2. Moscow 125412 (Russian Federation); Institut fuer Physik, Humboldt-Universitaet zu Berlin, Newtonstrasse 15, D-12489 Berlin (Germany)

    2011-04-18

    Highlights: The review of the critical opalescence problem is presented. Light scattering in a two-component electron-nuclear system is studied. The exact relations between the structure factors and compressibility are found. The obtained relations are valid for strong interaction for the Coulomb systems. The experimental verification of these relations is possible for various elements. - Abstract: Based on the dielectric formalism and quantum field theory methods, the phenomenon of critical opalescence is explained for light scattering in pure matter as a two-component electron-nuclear system with Coulomb interaction. A similar phenomenon is shown to occur in the case of neutron scattering in pure substances as well. The obtained results are valid for quantum case and arbitrary strong Coulomb interaction. Thus, the relations between structure factors derived for the electron-nuclear system are the exact result of the quantum statistical mechanics.

  9. Critical opalescence in the pure Coulomb system

    International Nuclear Information System (INIS)

    Bobrov, V.B.; Trigger, S.A.

    2011-01-01

    Highlights: → The review of the critical opalescence problem is presented. → Light scattering in a two-component electron-nuclear system is studied. → The exact relations between the structure factors and compressibility are found. → The obtained relations are valid for strong interaction for the Coulomb systems. → The experimental verification of these relations is possible for various elements. - Abstract: Based on the dielectric formalism and quantum field theory methods, the phenomenon of critical opalescence is explained for light scattering in pure matter as a two-component electron-nuclear system with Coulomb interaction. A similar phenomenon is shown to occur in the case of neutron scattering in pure substances as well. The obtained results are valid for quantum case and arbitrary strong Coulomb interaction. Thus, the relations between structure factors derived for the electron-nuclear system are the exact result of the quantum statistical mechanics.

  10. Study Proposal

    African Journals Online (AJOL)

    MATHEMATICS DEPARTMENT

    This cross sectional study design on mathematical syllabi at preparatory levels of the high schools was to ... Technology, Computer Science and Applied Sciences. It is studied of ..... For example, Jimma University Medical faculty students ...

  11. Initial Study

    DEFF Research Database (Denmark)

    Torp, Kristian

    2009-01-01

    increased. In the initial study presented here, the time it takes to pass an intersection is studied in details. Two major signal-controlled four-way intersections in the center of the city Aalborg are studied in details to estimate the congestion levels in these intersections, based on the time it takes...

  12. Game Studies

    NARCIS (Netherlands)

    Raessens, J.F.F.

    2016-01-01

    This entry describes game studies as a dynamic interdisciplinary field of academic study and research that focuses on digital games and play in a wide variety of social and cultural contexts. It examines the history of game studies from its prehistory, when games were looked at as part of other

  13. HTS Teologiese Studies / Theological Studies

    African Journals Online (AJOL)

    HTS Teologiese Studies/Theological Studies is an acclaimed Open Access journal with broad coverage that promotes multidisciplinary, religious, and biblical aspects of studies in the international theological arena. The journal's publication criteria are based on high ethical standards and the rigor of the methodology and ...

  14. Study protocol

    DEFF Research Database (Denmark)

    Thorsteinsson, Troels; Helms, Anne Sofie; Adamsen, Lis

    2013-01-01

    , and problems related to interaction with peers. Methods/design The RESPECT study is a nationwide population-based prospective, controlled, mixed-methods intervention study looking at children aged 6-18 years newly diagnosed with cancer in eastern Denmark (n = 120) and a matched control group in western Denmark......, and one year after the cessation of treatment. The study is powered to quantify the impact of the combined educational, physical, and social intervention programs. Discussion RESPECT is the first population-based study to examine the effect of early rehabilitation for children with cancer, and to use...

  15. Absorption studies

    International Nuclear Information System (INIS)

    Ganatra, R.D.

    1992-01-01

    Absorption studies were once quite popular but hardly anyone does them these days. It is easier to estimate the blood level of the nutrient directly by radioimmunoassay (RIA). However, the information obtained by estimating the blood levels of the nutrients is not the same that can be obtained from the absorption studies. Absorption studies are primarily done to find out whether some of the essential nutrients are absorbed from the gut or not and if they are absorbed, to determine how much is being absorbed. In the advanced countries, these tests were mostly done to detect pernicious anaemia where vitamin B 12 is not absorbed because of the lack of the intrinsic factor in the stomach. In the tropical countries, ''malabsorption syndrome'' is quire common. In this condition, several nutrients like fat, folic acid and vitamin B 12 are not absorbed. It is possible to study absorption of these nutrients by radioisotopic absorption studies

  16. Clinical Studies

    DEFF Research Database (Denmark)

    Pallesen, Ulla

    universities and practicing dentists restore millions of teeth throughout the World with composite resin materials. Do we know enough about the clinical performance of these restorations over time? Numerous in vitro studies are being published on resin materials and adhesion, some of them attempting to imitate...... in vivo conditions. But real life is different and in vitro studies cannot include all variables. Only clinical studies can provide valid information on the clinical performance of restorations over time. What do we know about longevity of posterior resin restorations? What are the reasons for replacement...... and results from own up to 30-year prospective clinical university studies and practice based studies from Public Dental Health Service on the clinical performance of posterior composite resin restorations....

  17. Hydrogeological study

    International Nuclear Information System (INIS)

    Massa, E.; Carrion, R.

    1987-01-01

    This work refers to the hydrogeological study about underground water to domestic uses. It was required by Artigas intendence of Uruguay, in the rural school 10, located belongs to the Chiflero zone around the capital of the Artigas Province.

  18. Feasibility study

    International Nuclear Information System (INIS)

    Gibbs, P.; Kalas, P.

    1975-01-01

    The feasibility study itself examines the technical, economic and financial implications of a nuclear power station in depth so as to make sure that nuclear power is the right course to take. This means that it is quite an expensive operation and it is to avoid wasting this money that a pre-feasibility study is carried out. This preliminary study should eliminate cases where the electrical system cannot absorb the capacity of a nuclear station of commercial size, where other sources of power such as hydro-electricity, gas or cheap coal would make nuclear obviously uneconomic or where no suitable sites exist. If this first rather simple survey shows that nuclear power is a credible solution to a utilities need for electricity or heat production plant, then the next stage is a full feasibility study. (orig./TK) [de

  19. INTERHEART STUDY

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. INTERHEART STUDY. About 90% of CHD Risk (“PAR”) can be explained by 9 Risk Factors: Smoking. Dyslipidemia. High BP. Diabetes. Abdominal Obesity. Psychosocial Factors. Fruits & Vegetables. Exercise. Alcohol.

  20. Study Drugs

    Science.gov (United States)

    ... to quit, they may have withdrawal symptoms like depression, thoughts of suicide, intense drug cravings, sleep problems, and fatigue. The health risks aren't the only downside to study drugs. Students caught with illegal prescription drugs may get suspended ...

  1. Environmental studies

    International Nuclear Information System (INIS)

    Mohd Tadza Abd Rahman

    2003-01-01

    Nuclear Technology offers unique method, yet effective for environmental research. Nuclear techniques are invented to carry out research activities on environmental pollutions, erosion and slope stability, landslide ground water studies and water pollution

  2. Floodplain Study

    Data.gov (United States)

    Montgomery County of Maryland — The purpose of a floodplain study is to establish the 100-year floodplain limits within or near a development in order to preserve the natural resources within the...

  3. Creole Studies

    DEFF Research Database (Denmark)

    This book launches a new approach to creole studies founded on phylogenetic network analysis. Phylogenetic approaches offer new visualisation techniques and insights into the relationships between creoles and non-creoles, creoles and other contact varieties, and between creoles and lexifier...... languages. With evidence from creole languages in Africa, Asia, the Americas, and the Pacific, the book provides new perspectives on creole typology, cross-creole comparisons, and creole semantics. The book offers an introduction for newcomers to the fields of creole studies and phylogenetic analysis. Using...... these methods to analyse a variety of linguistic features, both structural and semantic, the book then turns to explore old and new questions and problems in creole studies. Original case studies explore the differences and similarities between creoles, and propose solutions to the problems of how to classify...

  4. Actuarial Studies

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Office of the Actuary in the Centers for Medicare and Medicaid Services (CMS) from time to time conducts studies on various aspects of the Medicare and Medicaid...

  5. ARHCO studies

    International Nuclear Information System (INIS)

    Rogers, L.E.

    1977-01-01

    Ecological studies at the Hanford Reservation are designed to clarify ecosystem structure and function in and near the radioactive waste management areas. To date, emphasis has been placed on characterizing the abiotic and biotic components of these areas. During the current year, deer, raptors, coots, and mice have been under active study with respect to their potential for dissemination of radioactivity from pond or burial locations via feeding

  6. European Studies

    Directory of Open Access Journals (Sweden)

    V. O. Pechatnov

    2014-01-01

    Full Text Available The study of Western countries and teaching courses on the related subjects have longstanding and established tradition at MGIMO-University. The basis of this brilliant research and teaching tradition was laid down by such academicians as E.V. Tarle and V.G. Trukhanovsky, Professor L.I. Clove, Y. Borisov, F.I. Notovitch, G.L. Rozanov. Their work in 1940-1960's at the Department of World History at MGIMO-University progressed in following directions: France studies, German studies, American studies. The work resulted in a number of monographs and textbooks on modern history and foreign policy of the studied countries and regions. The aim of the publications was dictated by the goal of the Institute - to prepare the specialists in international affairs primarily for practical work. A close relationship with the Foreign Ministry was "binding advantage" sometimes limiting researchers in choosing periods and subjects for the study. At the same time the undisputed advantage and quality of regional studies at MGIMO were strengthened by the practical relevance of research, making it a vital and interesting not only for specialists but also for students and researchers from other research centers. Another characteristic of the tradition is the analysis of foreign policy and diplomacy in a close relationship with the socio-economic and political processes. Such an integrated approach to regional geography also formed largely under the influence of institutional profile designed to train highly skilled and versatile specialists in specific countries and regions with a good knowledge of their languages, history, economics, politics, law and culture. Therefore, scientific and educational-methodical work at MGIMO-University has always relied on a wealth of empirical data and has been focused on the analysis of real-world phenomena and processes, acute problems of foreign countries. Scientific research at MGIMO-University traditionally intertwined with

  7. Club studies

    DEFF Research Database (Denmark)

    Demant, Jakob Johan; Ravn, Signe; Harder, Sidsel Kirstine

    2010-01-01

    Club studies are sociological investigations of youth drug use in the social situation of the club. By being present at the club the researcher tries to gain access to a somehow hidden population of drug users who only to a lesser extent perceive their drug use as problematic. In spite of impress......Club studies are sociological investigations of youth drug use in the social situation of the club. By being present at the club the researcher tries to gain access to a somehow hidden population of drug users who only to a lesser extent perceive their drug use as problematic. In spite...... of impressive club studies conducted in both Great Britain and in the United States, it seems that, broadly speaking, previous efforts can be characterized as either very broad and/or quantitative or very particular, sub-cultural and exclusively qualitative. Through a review of these studies, this article...... suggests a mixed-methods approach to club studies that combine quantitative data, qualitative interviews and ethnography conducted in the club space. By introducing the concept of ‘socionautics', this review suggests that the researcher travels into the social landscape of youth, clubs and drugs...

  8. Host-guest interaction of styrene and ethylbenzene in MIL-53 studied by solid-state NMR.

    Science.gov (United States)

    Li, Shenhui; Li, Jing; Tang, Jing; Deng, Feng

    Solid-state NMR was utilized to explore the host-guest interaction between adsorbate and adsorbent at atomic level to understand the separation mechanism of styrene (St) and ethylbenzene (EB) in MIL-53(Al). 13 C- 27 Al double-resonance NMR experiments revealed that the host-guest interaction between St and MIL-53 was much stronger than that of EB adsorption. In addition, 13 C DIPSHIFT experiments suggested that the adsorbed St was less mobile than EB confined inside the MIL-53 pore. Furthermore, the host-guest interaction model between St, EB and MIL-53 was established on the basis of the spatial proximities information extracted from 2D 1 H- 1 H homo-nuclear correlation NMR experiments. According to the experimental observation from solid-state NMR, it was found that the presence of π-π interaction between St and MIL-53 resulted in the stronger host-guest interaction and less mobility of St. This work provides direct experimental evidence for understanding the separation mechanism of St and EB using MIL-53 as an adsorbent. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Studying Sideways

    DEFF Research Database (Denmark)

    Plesner, Ursula

    2011-01-01

    inequalities in relation to the people we study. This article argues that not all types of social scientific research interviews benefit from an à priori problematization of power and control, ethics and equality, or emancipation. From a constructivist perspective, the article seeks to displace......, we must cultivate interview methods which cause confrontation and disagreement—not to acknowledge asymmetry but to enhance the quality of research.......One strand of the qualitative interview literature has been concerned with the normative or otherwise problematic implications of studying down or studying up (i.e., interviewing “disadvantaged” people or elites). This interview literature is part of a tradition of taking up the problem of power...

  10. Invisibility Studies

    DEFF Research Database (Denmark)

    Invisibility Studies explores current changes in the relationship between what we consider visible and what invisible in different areas of contemporary culture. Contributions trace how these changes make their marks on various cultural fields and investigate the cultural significance of these de......Invisibility Studies explores current changes in the relationship between what we consider visible and what invisible in different areas of contemporary culture. Contributions trace how these changes make their marks on various cultural fields and investigate the cultural significance...... conditioned by physical and social settings that create certain possibilities for visibility and visuality, yet exclude others. The richness and complexity of this cultural framework means that no single discipline or interdisciplinary approach could capture it single-handedly. Invisibility Studies begins...

  11. Project studies

    DEFF Research Database (Denmark)

    Geraldi, Joana; Söderlund, Jonas

    2018-01-01

    Project organising is a growing field of scholarly inquiry and management practice. In recent years, two important developments have influenced this field: (1) the study and practice of projects have extended their level of analysis from mainly focussing on individual projects to focussing on micro......, and of the explanations of project practices they could offer. To discuss avenues for future research on projects and project practice, this paper suggests the notion of project studies to better grasp the status of our field. We combine these two sets of ideas to analyse the status and future options for advancing...... project research: (1) levels of analysis; and (2) type of research. Analysing recent developments within project studies, we observe the emergence of what we refer to as type 3 research, which reconciles the need for theoretical development and engagement with practice. Type 3 research suggests pragmatic...

  12. Study protocol

    DEFF Research Database (Denmark)

    Smith, Benjamin E; Hendrick, Paul; Bateman, Marcus

    2017-01-01

    avoidance behaviours, catastrophising, self-efficacy, sport and leisure activity participation, and general quality of life. Follow-up will be 3 and 6 months. The analysis will focus on descriptive statistics and confidence intervals. The qualitative components will follow a thematic analysis approach....... DISCUSSION: This study will evaluate the feasibility of running a definitive large-scale trial on patients with patellofemoral pain, within the NHS in the UK. We will identify strengths and weaknesses of the proposed protocol and the utility and characteristics of the outcome measures. The results from...... this study will inform the design of a multicentre trial. TRIAL REGISTRATION: ISRCTN35272486....

  13. Study Drugs

    OpenAIRE

    Lam, Stephanie Phuong; Roosta, Natalie; Nielsen, Mikkel Fuhr; Meyer, Maria Holmgaard; Friis, Katrine Birk

    2016-01-01

    In recent years, students around the world, started to use preparations as Ritalin and Modafinil,also known as study drugs, to improve their cognitive abilities1. It is a common use among thestudents in United States of America, but it is a new tendency in Denmark. Our main focus is tolocate whether study drugs needs to be legalized in Denmark or not. To investigate this ourstarting point is to understand central ethical arguments in the debate. We have chosen twoarguments from Nick Bostrom a...

  14. Security studies

    International Nuclear Information System (INIS)

    Venot, R.

    2001-01-01

    Full text: Security studies constitute one of the major tools for evaluating the provisions implemented at facilities to protect and control Nuclear Material against unauthorized removal. Operators use security studies to demonstrate that they are complying with objectives set by the Competent Authority to counter internal or external acts aimed at unauthorized removal of NM. The paper presents the context of security studies carried out in France. The philosophy of these studies is based on a postulated unauthorized removal of NM and the study of the behavior of the systems implemented to control and protect NM in a facility. The potential unauthorized removal of NM usually may take place in two stages. The first stage involves the sequence leading to handling of the NM. It occurs inside the physical barriers of a facility and may include action involving the documents corresponding to Material Control and Accounting systems. At this stage it is possible to limit the risk of unauthorized removal of NM by means of detection capabilities of the MC and A systems. The second stage is more specific to theft and involves removing the NM out of the physical barriers of a facility in which they are being held, notably by affecting the Physical Protection System. Operators have to study, from a quantity and time lapse point of view, the ability of the installed systems to detect unauthorized removal, as well as the possibility of tampering with the systems to mask unlawful operations. Operators have also to analyze the sequences during which NM are accessed, removed from their containment and further removed from the facility in which they are stored. At each stage in the process, the probability of detection and the time taken to carry out the above actions have to be estimated. Of course, these two types of studies complement each other. Security studies have begun, in France, for more than fifteen years. Up to now more than fifty security studies are available in the

  15. Polarization study

    International Nuclear Information System (INIS)

    Nurushev, S.B.

    1989-01-01

    Brief review is presented of the high energy polarization study including experimental data and the theoretical descriptions. The mostimportant proposals at the biggest accelerators and the crucial technical developments are also listed which may become a main-line of spin physics. 35 refs.; 10 figs.; 4 tabs

  16. Hydrogeological study

    International Nuclear Information System (INIS)

    Massa, E.; Heinzen, W.; Santana, J.

    1987-01-01

    This work shows the hydrogeological study and well drilling carried out in the Teaching Formation Institute San Jose de Mayo Province Uruguay. It was developed a geological review in the National Directorate of Geology and Mining data base as well as field working, geology and hydrogeology recognition and area well drilling inventory.

  17. Immunology studies

    International Nuclear Information System (INIS)

    Smith, D.M.; Baron, P.A.; Drake, G.A.; LaBauve, P.M.; London, J.E.; Wilson, J.S.

    1977-01-01

    The following studies were conducted in the field of immunology; a model system to determine toxic effects on the immune system using 3 H-uridine uptake by Feells of rats; and survival in lethally irradiatd mice receiving allogenic fetal liver and thymus

  18. CASE STUDY

    African Journals Online (AJOL)

    2011-06-02

    Jun 2, 2011 ... immunosuppression associated with HIV/AIDS puts them at a higher risk of developing oesophageal cancer. 47. CASE STUDY. A 49-year-old man was diagnosed as HIV infected, with a CD4 count of 60 cells/µl. He was started on an antiretroviral treatment regimen comprising zidovudine, lamivudine and ...

  19. ENDOR with band-selective shaped inversion pulses

    Science.gov (United States)

    Tait, Claudia E.; Stoll, Stefan

    2017-04-01

    Electron Nuclear DOuble Resonance (ENDOR) is based on the measurement of nuclear transition frequencies through detection of changes in the polarization of electron transitions. In Davies ENDOR, the initial polarization is generated by a selective microwave inversion pulse. The rectangular inversion pulses typically used are characterized by a relatively low selectivity, with full inversion achieved only for a limited number of spin packets with small resonance offsets. With the introduction of pulse shaping to EPR, the rectangular inversion pulses can be replaced with shaped pulses with increased selectivity. Band-selective inversion pulses are characterized by almost rectangular inversion profiles, leading to full inversion for spin packets with resonance offsets within the pulse excitation bandwidth and leaving spin packets outside the excitation bandwidth largely unaffected. Here, we explore the consequences of using different band-selective amplitude-modulated pulses designed for NMR as the inversion pulse in ENDOR. We find an increased sensitivity for small hyperfine couplings compared to rectangular pulses of the same bandwidth. In echo-detected Davies-type ENDOR, finite Fourier series inversion pulses combine the advantages of increased absolute ENDOR sensitivity of short rectangular inversion pulses and increased sensitivity for small hyperfine couplings of long rectangular inversion pulses. The use of pulses with an almost rectangular frequency-domain profile also allows for increased control of the hyperfine contrast selectivity. At X-band, acquisition of echo transients as a function of radiofrequency and appropriate selection of integration windows during data processing allows efficient separation of contributions from weakly and strongly coupled nuclei in overlapping ENDOR spectra within a single experiment.

  20. Pilot study

    International Nuclear Information System (INIS)

    Hofmeester, G.H.; Swart, A.; Dijk, E. van

    1984-01-01

    In May 1980 it was decided to organize an intercomparison of personal dosimeters for photon radiations. The Commission of the European Communities initiated the intercomparison by starting a pilot study in which three laboratories NPL (United Kingdom), PTB (Germany) and RIV (The Netherlands) were asked to irradiate a series of personal dosemeters from institutes, GSF (Muenchen), CEA (Fontenay-aux-Roses), CNEN (Bologna) and CEGB (Berkeley). The latter institutes are secondary standard laboratories and have a radiation protection service as well. A new aspect of this pilot study is the fact that the irradiations also take place in front of a phantom. Irradiations took place in July and August 1980. The results of 4 institutes show that the personal dosemeters are quite capable of measuring the backscattered photon components

  1. Study Strategies

    DEFF Research Database (Denmark)

    Nielsen, Camilla Kirketerp; Noer, Vibeke Røn

    and theory forms the basis of the research. Veterinary students have been followed through alternating learning contexts referring to both the scholastic academic classrooms and workplaces in commercial pig herds as well as to group work and game-based situations in a mandatory master course - ”the pig...... as a student´ and the process of professionalization. By maintaining the position of focusing upon the education as a situated and formative trajectory, the comparative analysis shows how students in profession-oriented educational settings manage the challenges of education and use study strategies......ID: 1277 / 22 SES 06 B: 2 22. Research in Higher Education Format of Presentation: Paper Alternative EERA Network: 19. Ethnography Topics: NW 22: Teaching, learning and assessment in higher education Keywords: Profession-oriented learning, study strategies, professionalisation processes...

  2. Economic Studies

    Directory of Open Access Journals (Sweden)

    A. V. Kholopov

    2014-01-01

    Full Text Available The establishment of the School of Economic Science at MGIMO was due to the necessity of the world economy research, and the need to prepare highly skilled specialists in international economics. The school is developing a number of areas, which reflect the Faculty structure. - Economic theory is one of the most important research areas, a kind of foundation of the School of Economic Science at MGIMO. Economic theory studies are carried out at the chair of Economic theory. "The course of economic theory" textbook was published in 1991, and later it was reprinted seven times. Over the past few years other textbooks and manuals have been published, including "Economics for Managers" by Professor S.N. Ivashkovskaya, which survived through five editions; "International Economics" - four editions and "History of Economic Thought" - three editions. - International Economic Relations are carried out by the Department of International Economic Relations and Foreign Economic Activity. Its establishment is associated with the prominent economist N.N. Lyubimov. In 1957 he with his colleagues published the first textbook on the subject which went through multiple republications. The editorial team of the textbook subsequently formed the pride of Soviet economic science - S.M. Menshikov, E.P. Pletnev, V.D. Schetinin. Since 2007, the chair of Foreign Economic Activities led by Doctor of Economics, Professor I. Platonova has been investigating the problems of improving the architecture of foreign economic network and the international competitiveness of Russia; - The history of the study of problems of the world economy at MGIMO begins in 1958 at the chair baring the same name. Since 1998, the department has been headed by Professor A. Bulatov; - The study of international monetary relations is based on the chair of International Finance, and is focused on addressing the fundamental scientific and practical problems; - The chair "Banks, monetary circulation

  3. Studying Emerge

    DEFF Research Database (Denmark)

    Davies, Sarah Rachael; Selin, Cynthia; Rodegher, Sandra

    2015-01-01

    The Emerge event, held in Tempe, AZ in March 2012, brought together a range of scientists, artists, futurists, engineers and students in order to experiment with innovative methods for thinking about the future. These methodological techniques were tested through nine workshops, each of which made...... use of a different format; Emerge as a whole, then, offered an opportunity to study a diverse set of future-oriented engagement practices. We conducted an event ethnography, in which a team of 11 researchers collaboratively developed accounts of the practices at play within Emerge and its workshops...

  4. Law Studies

    Directory of Open Access Journals (Sweden)

    G. P. Tolstopiatenko

    2014-01-01

    Full Text Available At the origin of the International Law Department were such eminent scientists, diplomats and teachers as V.N. Durdenevsky, S.B. Krylov and F.I. Kozhevnikov. International law studies in USSR and Russia during the second half of the XX century was largely shaped by the lawyers of MGIMO. They had a large influence on the education in the international law in the whole USSR, and since 1990s in Russia and other CIS countries. The prominence of the research of MGIMO international lawyers was due to the close connections with the international practice, involving international negotiations in the United Nations and other international fora, diplomatic conferences and international scientific conferences. This experience is represented in the MGIMO handbooks on international law, which are still in demand. The Faculty of International Law at MGIMO consists of seven departments: Department of International Law, Department of Private International and Comparative Law; Department of European Law; Department of Comparative Constitutional Law; Department of Administrative and Financial Law; Department of Criminal Law, Department Criminal Procedure and Criminalistics. Many Russian lawyers famous at home and abroad work at the Faculty, contributing to domestic and international law studies. In 1947 the Academy of Sciences of the USSR published "International Law" textbook which was the first textbook on the subject in USSR. S.B. Krylov and V.N. Durdenevsky were the authors and editors of the textbook. First generations of MGIMO students studied international law according to this textbook. All subsequent books on international law, published in the USSR, were based on the approach to the teaching of international law, developed in the textbook by S.B. Krylov and V.N. Durdenevsky. The first textbook of international law with the stamp of MGIMO, edited by F.I. Kozhevnikov, was published in 1964. This textbook later went through five editions in 1966, 1972

  5. Immunology studies

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Three efforts dealing with the role of the immune state have continued to show promise over the last year. The first deals with the development of animal models for testing the part played by immune dysfunction in carcinogenesis. The second and related program is a clinical study of high-risk uranium miners whose status in relation to neoplastic manifestations is rather well-defined. The third program is one in which fetal tissue is used to attempt the rescue of lethally irradiated hosts

  6. Untitled

    Indian Academy of Sciences (India)

    ,10-dihalo compounds) and their triplet formation. T Nakayama, K Ibuki and K Hamanoue ... Electron-nuclear cross-relaxation effect on the photochemical reaction of benzaldehyde as studied by CIDNP and DNP Y Yamakage,. Q Meng, S S Ali, ...

  7. Geologic studies

    International Nuclear Information System (INIS)

    Wayland, T.E.; Rood, A.

    1983-01-01

    The modern Great Divide Basin is the end product of natural forces influenced by the Green River lake system, Laramide tectonism, and intermittent volcanic events. It ranks as one of the most complex structural and stratigtaphic features within the Tertiary basins of Wyoming. Portions of the Great Divide Basin and adjoining areas in Wyoming have been investigated by applying detailed and region exploration methods to known uranium deposits located within the Red Desert portions of the basin. Geologic field investigations conducted by Bendix Field Engineering Corporaton (Bendix) were restricted to reconnaissance observations made during infrequent visits to the project area by various Bendix personnel. Locations of the most comprehensive field activities are shown in Figure II-1. The principal source fo data for geologic studies of the Red Desert project area has been information and materials furnished by industry. Several hundred holes have been drilled by various groups to delineate the uranium deposits. Results from Bendix-drilled holes at selected locations within the project area are summarized in Table II-1. Additional details and gross subsurface characteristics are illustrated in cross sections; pertinent geologic features are illustrated in plan maps. Related details of continental sedimentation that pertain to the Wyoming Basins generally, and the project area specificially, are discussed in subsections of this Geologic Studies section

  8. Aerosol studies

    International Nuclear Information System (INIS)

    Cristy, G.A.; Fish, M.E.

    1978-01-01

    As part of the continuing studies of the effects of very severe reactor accidents, an effort was made to develop, test, and improve simple, effective, and inexpensive methods by which the average citizen, using only materials readily available, could protect his residence, himself, and his family from injury by toxic aerosols. The methods for protection against radioactive aerosols should be equally effective against a clandestine biological attack by terrorists. The results of the tests to date are limited to showing that spores of the harmless bacterium, bacillus globegii (BG), can be used as a simulant for the radioactive aerosols. An aerosol generator of Lauterbach type was developed which will produce an essentially monodisperse aerosol at the rate of 10 9 spores/min. Analytical techniques have been established which give reproducible results. Preliminary field tests have been conducted to check out the components of the system. Preliminary tests of protective devices, such as ordinary vacuum sweepers, have given protection factors of over 1000

  9. Conceptual study

    Energy Technology Data Exchange (ETDEWEB)

    Harty, H.

    1978-09-01

    This appendix is a compendium of topical reports prepared for the Hanford Nuclear Energy Center: Status Report: Conceptual Fuel Cycle Studies for the Hanford Nuclear Energy Center; Selection of Heat Disposal Methods for a Hanford Nuclear Energy Center; Station Service Power Supply for a Hanford Nuclear Energy Center (HNEC); Impact of a Hanford Nuclear Energy Center on Ground Level Fog and Humidity; A Review of Potential Technology for the Seismic Characterization of Nuclear Energy Centers; Reliability of Generation at a Hanford Nuclear Energy Center (HNEC); Meteorological Evaluation of Multiple Reactor Contamination Probabilities for a Hanford Nuclear Energy Center; Electric Power Transmission for a Hanford Nuclear Energy Center (HNEC); The Impact of a Hanford Nuclear Energy Center on Cloudiness and Insolation; and A Licensing Review for an HNEC.

  10. Terrestrial studies

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Tritium in the organic fraction of soil, separated as water by high temperature combustion, was 5 to 50 times higher in activity than water that was freeze-dried from the same samples. The 50-year dose commitment from ingestion of crops is not influenced significantly by the plutonium in the SRP environment. This plutonium is a result of more than 20 years of operating chemical separations facilities. Techniques were developed to detect as little as 0.02 pCi/m 2 of iodine-129 and 0.2 pg of technetium-99 in soil to evaluate environmental effects. A sensitive three-stage mass spectrometer was completed for use in environmental studies of transuranium elements. Results of monitoring particle size distribution of entrapped particles containing Pu-238, and Pu-239,240 are reported

  11. Conceptual study

    International Nuclear Information System (INIS)

    Harty, H.

    1978-09-01

    This appendix is a compendium of topical reports prepared for the Hanford Nuclear Energy Center: Status Report: Conceptual Fuel Cycle Studies for the Hanford Nuclear Energy Center; Selection of Heat Disposal Methods for a Hanford Nuclear Energy Center; Station Service Power Supply for a Hanford Nuclear Energy Center (HNEC); Impact of a Hanford Nuclear Energy Center on Ground Level Fog and Humidity; A Review of Potential Technology for the Seismic Characterization of Nuclear Energy Centers; Reliability of Generation at a Hanford Nuclear Energy Center (HNEC); Meteorological Evaluation of Multiple Reactor Contamination Probabilities for a Hanford Nuclear Energy Center; Electric Power Transmission for a Hanford Nuclear Energy Center (HNEC); The Impact of a Hanford Nuclear Energy Center on Cloudiness and Insolation; and A Licensing Review for an HNEC

  12. Studying antimatter

    CERN Multimedia

    CERN. Geneva

    2006-01-01

    Antiparticles are a crucial ingredient of particle physics and cosmology. Almost 80 years after Dirac’s bold prediction and the subsequent discovery of the positron in 1932, antiparticles are still in the spotlight of modern physics. This lecture for non-specialists will start with a theoretical and historical introduction. Why are antiparticles needed? When and how were they discovered? Why is the (CPT) symmetry between particles and antiparticles so fundamental? What is their role in cosmology? The second part will give an overview about the many aspects of antiparticles in experimental physics: their production, their use in colliders; as a probe inside atoms or nuclei; or as an object to study fundamental symmetries. In the third part, the lecture will focus on results and challenges of the “antimatter” programme at the Antiproton Decelerator (AD), with special emphasis on antihydrogen production, trapping and precision measurements.

  13. Spectroscopic study

    International Nuclear Information System (INIS)

    Flores, M.; Rodriguez, R.; Arroyo, R.

    1999-01-01

    This work is focused about the spectroscopic properties of a polymer material which consists of Polyacrylic acid (Paa) doped at different concentrations of Europium ions (Eu 3+ ). They show that to stay chemically joined with the polymer by a study of Nuclear Magnetic Resonance (NMR) of 1 H, 13 C and Fourier Transform Infrared Spectroscopy (Ft-IR) they present changes in the intensity of signals, just as too when this material is irradiated at λ = 394 nm. In according with the results obtained experimentally in this type of materials it can say that is possible to unify chemically the polymer with this type of cations, as well as, varying the concentration of them, since that these are distributed homogeneously inside the matrix maintaining its optical properties. These materials can be obtained more quickly and easy in solid or liquid phase and they have the best conditions for to make a quantitative analysis. (Author)

  14. American Studies

    Directory of Open Access Journals (Sweden)

    V. O. Pechatnov

    2014-01-01

    Full Text Available The "Founding fathers" of American Studies at MGIMO are considered to be A.V. Efimov and L.I. Clove. Alexey Efimov - Corresponding Member of the USSR Academy of Sciences since 1938, Head of the Department of Modern and Contemporary History and Dean of the Historical School at the Moscow State University - one of the first professors of the Faculty of International Relations MGIMO. Efimov distinguished himself by a broad vision and scope of scientific interests. Back in 1934 he published a monograph "On the history of capitalism in the United States," which initiated a series of research culminating in the fundamental work "The United States. The path of capitalist development (pre-imperialist era". Alexey was not only a great scientist but also a great teacher, whose lectures was popular throughout Moscow. His lecture courses, given at the end of the 1940s at MGIMO, became the basis for the first post-war history textbooks USA - "Essays on the history of the United States." At least as colorful a figure was Professor Leo Izrailevich Zubok - a man of unusual destiny. As a teenager he emigrated to the United States with his parents, where he soon joined the American revolutionary movement in the 1920s and was forced to leave the country. He came to MGIMO being already an experienced scientists. His research interests were very wide: from the study of American foreign policy expansion to the history of the labor movement in the United States. Zubok's fundamental works still have not lost its scientific significance. He has successfully combined scientific work with teaching. Tutorials that are based on his lectures were very popular not only among students of MGIMO.

  15. Aquatic studies

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Thermal stress to microorganisms was measured by the production of dissolved organic matter by algal communities and the mineralization of glucose by heterotrophic populations. Mutagenic activity as measured by the Ames/Salmonella/microsome assay indicate that such activity does not occur in Par Pond, although limited mutagenic activity does occur in a nearby canal system due to chlorination of cooling water. Sodium hypochlorite, used as an algicide in the reactor fuel storage basins, caused increased pitting corrosion to reactor fuel targets. Five other compounds selected for testing proved to be superior to sodium hypochlorite. Legionella pneumophila, the pathogen which causes Legionnaire's disease, was found to be a natural part of aquatic ecosystems. It occurs over a wide range of environments and is able to utilize nutrients provided by primary producers. Phytoplankton size classes of less than 3 μm (less than 5% of the total phytoplankton biomass) accounted for 15 to 40% of the total primary productivity in Par Pond, Pond C, and Clark Hill Reservoir. Three major biological data sets were compiled and are available in the SRL computer system for analysis: the SRP deer herd data; 20 years of Par Pond data; and 25 years of biological data on the Savannah River. Results of marine studies indicated that nearly all plutonium in the Savannah River and its estuary resulted from nuclear weapons fallout. The plutonium concentration in the Savannah River is about one fourth the concentration in the Newport River which has no nuclear operations associated with it

  16. Catalysis studies

    International Nuclear Information System (INIS)

    Taylor, T.N.; Ellis, W.P.

    1977-11-01

    The New Research Initiatives Program (NRIP) project on catalysis in Los Alamos Scientific Laboratory (LASL) Group CMB-8 has made significant progress towards performing the first basic in situ experimental studies of heterogeneous catalysis on solid compound surfaces in a LEED-Auger system. To further understand the surface crystallography of a possible catalyst compound, LEED-Auger measurements were made on UO 2 (approximately 100) vicinal surfaces. These (approximately 100) vicinal surfaces were shown to decompose irreversibly into lower index facets, including prominent (100) facets, at temperatures below those needed for creation of lowest index faceting on (approximately 111) vicinal surfaces. LEED examination of fully faceted surfaces from both types of UO 2 vicinal cuts did not show evidence of cyclopropane or propene chemisorption. The existing LEED-Auger system was modified to allow catalytic reactions at approximately less than 10 -3 torr. A sample holder, specifically designed for catalysis measurements in the modified system, was tested while examining single crystals of CoO and Cr 2 O 3 . Extensive LEED-Auger measurements were made on CoO in vacuo and in the presence of light hydrocarbons and alcohols plus H 2 O, NO, and NH 3 . No chemisorptive behavior was observed except with H 2 O in the presence of the electron beam. Although only examined briefly, the Cr 2 O 3 was remarkable for the sharp LEED features obtained prior to any surface treatment in the vacuum system

  17. Quasibound levels and shape resonances of 39K2(B 1Pi/sub u/) crossed laser-molecular beam studies and analytical interpretation

    International Nuclear Information System (INIS)

    Heinze, J.; Kowalczyk, P.; Engelke, F.

    1988-01-01

    Quasibound levels and shape resonances in the (B 1 Pi/sub u/ -X 1 Σ + /sub g/) band system of 39 K 2 have been recorded by crossed laser-molecular beam techniques. Using optical--optical double resonance, individual rovibrational levels (v'' = 15--18, J'' = 3--25) of the K 2 state are prepared by Franck--Condon pumping (FCP) in a supersonic nozzle beam. Excitation into quasibound levels below and above the (B 1 Pi/sub u/) state barrier is detected as molecular and atomic (K4 2 P 3 /sub // 2 →4 2 S 1 /sub // 2 only) fluorescence. The resonance transition frequencies and shapes are measured and the results are used (a) to determine the scattering resonance energies, widths, and lifetimes; (b) to compare them with values obtained by a ''maximum internal amplitude'' approach [R. J. LeRoy and R. B. Bernstein, J. Chem. Phys. 54, 5114 (1971)]; and (c) to check the agreement with exact calculations of the B state potential using the ''inverted perturbation approach (IPA).'' The bound and quasibound part of the B 1 Pi/sub u/ state including the locus (R = 8.08 +- 0.05 A) of the barrier maximum (298 +- 8 cm -1 above the adiabatic dissociation limit) is found in excellent agreement with previous results. The shape resonances are not highly sensitive to the long-range interatomic forces, here the repulsive dipole--dipole resonance interaction

  18. Fostering Effective Studying and Study Planning with Study Questions

    Science.gov (United States)

    Wilhelm, Pascal; Pieters, Jules M.

    2007-01-01

    In a course on biological psychology and neuropsychology, study questions were provided that also appeared as test questions in the course exam. This method was introduced to support students in active processing and reproduction of the study texts, and study planning. Data were gathered to test the hypothesis that study question use would be…

  19. Case Study: Testing with Case Studies

    Science.gov (United States)

    Herreid, Clyde Freeman

    2015-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue discusses using case studies to test for knowledge or lessons learned.

  20. Fostering effective studying and study planning with study questions

    NARCIS (Netherlands)

    Wilhelm, P.; Pieters, J.M.

    2007-01-01

    In a course on biological psychology and neuropsychology, study questions were provided that also appeared as test questions in the course exam. This method was introduced to support students in active processing and reproduction of the study texts, and study planning. Data were gathered to test the

  1. Archives: HTS Teologiese Studies / Theological Studies

    African Journals Online (AJOL)

    Items 1 - 50 of 120 ... Archives: HTS Teologiese Studies / Theological Studies. Journal Home > Archives: HTS Teologiese Studies / Theological Studies. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Journal Home · ABOUT THIS JOURNAL · Advanced Search ...

  2. CASE STUDY CRITIQUE; UPPER CLINCH CASE STUDY

    Science.gov (United States)

    Case study critique: Upper Clinch case study (from Research on Methods for Integrating Ecological Economics and Ecological Risk Assessment: A Trade-off Weighted Index Approach to Integrating Economics and Ecological Risk Assessment). This critique answers the questions: 1) does ...

  3. Carbon and deuterium nuclear magnetic resonance in solids

    Energy Technology Data Exchange (ETDEWEB)

    Shattuck, Thomas Wayne [Univ. of California, Berkeley, CA (United States)

    1976-07-01

    In Chapter I we present the results on a study of cross polarization dynamics, between protons and carbon-13 in adamantane, by the direct observation of the dilute, carbon-13, spins. These dynamics are an important consideration in the efficiency of proton enhancement double-resonance techniques and they also provide good experimental models for statistical theories of cross relaxation. In order to test these theories we present a comparison of the experimental and theoretical proton dipolar fluctuation correlation time τc, which is experimentally 110 ± 15 μsec and theoretically 122 μsec for adamantane. These double resonance considerations provide the background for extensions to deuterium and double quantum effects discussed in Chapter II. In Chapter II an approach to high resolution nmr of deuterium in solids is described. The m = 1 → -1 transition is excited by a double quantum process and the decay of coherence Q(τ) is monitored. Fourier transformation yields a deuterium spectrum devoid of quadrupole splittings and broadening. If the deuterium nuclei are dilute and the protons are spin decoupled, the double-quantum spectrum is a high resolution one and yields information on the deuterium chemical shifts Δω. The relationship Q(τ) ~ cos 2Δωτ is checked and the technique is applied to a single crystal of oxalic acid dihydrate enriched to ~ 10% in deuterium. The carboxyl and the water deuterium shifts are indeed resolved and the anisotropy of the carboxyl shielding tensor is estimated to be Δσ = 32 ± 3 ppm. A complete theoretical analysis is presented. The extension of cross relaxation techniques, both direct and indirect, to proton-deuterium double resonance is also described. The m = 1 → -1 double quantum transition and the m = ± 1 → 0 single quantum transitions may all be polarized and we present the derivation of the Hartmann-Hahn cross polarization conditions for each case. In addition the dynamics of the double quantum process

  4. Spin-dependent recombination involving oxygen-vacancy complexes in silicon

    Science.gov (United States)

    Franke, David P.; Hoehne, Felix; Vlasenko, Leonid S.; Itoh, Kohei M.; Brandt, Martin S.

    2014-05-01

    Spin-dependent relaxation and recombination processes in γ-irradiated n-type Czochralski-grown silicon are studied using continuous wave (cw) and pulsed electrically detected magnetic resonance (EDMR). Two processes involving the SL1 center, the neutral excited triplet state of the oxygen-vacancy complex, are observed which can be separated by their different dynamics. One of the processes is the relaxation of the excited SL1 state to the ground state of the oxygen-vacancy complex, the other a charge transfer between 31P donors and SL1 centers forming close pairs, as indicated by electrically detected electron double resonance. For both processes, the recombination dynamics is studied with pulsed EDMR techniques. We demonstrate the feasibility of true zero-field cw and pulsed EDMR for spin-1 systems and use this to measure the lifetimes of the different spin states of SL1 also at vanishing external magnetic field.

  5. IR-IR Conformation Specific Spectroscopy of Na+(Glucose) Adducts

    Science.gov (United States)

    Voss, Jonathan M.; Kregel, Steven J.; Fischer, Kaitlyn C.; Garand, Etienne

    2018-01-01

    We report an IR-IR double resonance study of the structural landscape present in the Na+(glucose) complex. Our experimental approach involves minimal modifications to a typical IR predissociation setup, and can be carried out via ion-dip or isomer-burning methods, providing additional flexibility to suit different experimental needs. In the current study, the single-laser IR predissociation spectrum of Na+(glucose), which clearly indicates contributions from multiple structures, was experimentally disentangled to reveal the presence of three α-conformers and five β-conformers. Comparisons with calculations show that these eight conformations correspond to the lowest energy gas-phase structures with distinctive Na+ coordination. [Figure not available: see fulltext.

  6. Optical detection of magnetic resonance of the F-centre in CaO in its phosphorescent state

    International Nuclear Information System (INIS)

    Krap, C.J.

    1980-01-01

    The F-centre in CaO consists of two electrons trapped in an oxygen vacancy. The centre possesses bound excited states, of which the phosphorescent 3 Tsub(1u) state is a Jahn-Teller state. Jahn-Teller systems have been of interest in many investigations. However, detailed experimental studies about the relaxation paths for the Jahn-Teller states are relatively few. The author studies by means of optical detection of magnetic resonance (ODMR) and phosphorescence microwave double resonance (PMDR) techniques the relaxation between the components of the 3 Tsub(1u) state, the magnetic properties of the individual spin-vibronic Jahn-Teller states and the inhomogeneous line broadening in the ODMR and PMDR spectra. (Auth.)

  7. Building Transdisciplinary Environmental Studies

    DEFF Research Database (Denmark)

    Holm, Jesper

    2006-01-01

    Conceptual analytical-methodological conceptualization of crossdisciplinary sustainability studies......Conceptual analytical-methodological conceptualization of crossdisciplinary sustainability studies...

  8. WWC Study Review Guide: Group Design Studies

    Science.gov (United States)

    What Works Clearinghouse, 2018

    2018-01-01

    Underlying all What Works Clearinghouse (WWC) products are WWC Study Review Guides, which are intended for use by WWC certified reviewers to assess studies against the WWC evidence standards. As part of an ongoing effort to increase transparency, promote collaboration, and encourage widespread use of the WWC standards, the Institute of Education…

  9. German Studies in America. German Studies Notes.

    Science.gov (United States)

    Sander, Volkmar; Osterle, Heinz D.

    This volume contains two papers, "German Studies in America," by Volkmar Sander, and "Historicism, Marxism, Structuralism: Ideas for German Culture Courses," by Heinz D. Osterle. The first paper discusses the position of German studies in the United States today. The greatest challenge comes from low enrollments; therefore,…

  10. Study of lip prints: A forensic study

    Directory of Open Access Journals (Sweden)

    Vikash Ranjan

    2014-01-01

    Full Text Available Background: Although several studies have been done on lip prints for human identification in forensic science, there is a doubt about their use in gender determination. Aims: The present study was designed to study the lip groove patterns in all the quadrants of both male and female subjects to identify the sex, based on the patterns of the grooves of the lip prints. Study Design: 300 lip prints were collected from volunteers of D. J. College of Dental Sciences and Research, Modinagar (UP. Materials and Methods: Lip prints were recorded with lip stick and transferred on to a glass slide. Statistical Analysis: Pearson chi-square test was adopted for statistical analysis and probability value (P value was calculated. Conclusion: In our study, none of the lip prints were identical, thus confirming the role of lip prints in individual identification. According to Suzuki′s classification, Type I, II, III and IV patterns were significant in gender determination.

  11. Prompt and delayed excitation and photolysis of cesium dimers

    International Nuclear Information System (INIS)

    Davanloo, F.; Collins, C.B.; Inamdar, A.S.; Mehendale, N.Y.; Nagvi, A.S.

    1984-01-01

    In this work a time-delayed, double resonance technique was used for the study of the state selective photolysis of Cs 2 excited in the yellow range of visible wavelengths. Particular attention being placed on the production of the fine structure components of the 5 2 D and 6 2 P states of Cs and upon the lifetimes of the product populations in the cesium vapor. A quantitative model was constructed to fit the data and rate coefficients were extracted for processes tending to attenuate the product state selectivity. Reported here is what appears to be the first value for the fine-structure mixing cross section for Cs(5 2 D5/2 → 5 2 D 3 /sub 3/2/) of 17 A 2 +-50%, close to the geometric cross section

  12. Collisional Removal of O2 (c(sup 1) Sigma(sup-)(sub u), nu=9) by O2, N2, and He

    Science.gov (United States)

    Copeland, Richard A.; Knutsen, Karen; Onishi, Marc E.; Yalcin, Talat

    1996-01-01

    The collisional removal Of 02 molecules in selected vibrational levels of the c state is studied using a two-laser double-resonance technique. The output of the first laser excites the 02 to nu = 9 or 10 of the c Sigma - state, and the ultraviolet output of the second laser monitors specific rovibrational levels via resonance-enhanced ionization. The temporal evolution of the c Sigma u state vibrational level is observed by scanning the time delay between the two pulsed lasers. As the rate constants for 02 and N2 are similar in magnitude, N2 collisions dominate the removal rate in the earth's atmosphere. For v= 10 colliding with 02, we find a removal rate constant that is 2-5 times that for v=9 and that single quantum collision cascade is an important pathway for removal.

  13. Sine-squared shifted pulses for recoupling interactions in solid-state NMR

    Science.gov (United States)

    Jain, Mukul G.; Rajalakshmi, G.; Equbal, Asif; Mote, Kaustubh R.; Agarwal, Vipin; Madhu, P. K.

    2017-06-01

    Rotational-Echo DOuble-Resonance (REDOR) is a versatile experiment for measuring internuclear distance between two heteronuclear spins in solid-state NMR. At slow to intermediate magic-angle spinning (MAS) frequencies, the measurement of distances between strongly coupled spins is challenging due to rapid dephasing of magnetisation. This problem can be remedied by employing the pulse-shifted version of REDOR known as Shifted-REDOR (S-REDOR) that scales down the recoupled dipolar coupling. In this study, we propose a new variant of the REDOR sequence where the positions of the π pulses are determined by a sine-squared function. This new variant has scaling properties similar to S-REDOR. We use theory, numerical simulations, and experiments to compare the dipolar recoupling efficiencies and the experimental robustness of the three REDOR schemes. The proposed variant has advantages in terms of radiofrequency field requirements at fast MAS frequencies.

  14. Anomalous lattice vibrations of monolayer MoS 2 probed by ultraviolet Raman scattering

    KAUST Repository

    Liu, Hsiang Lin; Guo, Huaihong; Yang, Teng; Zhang, Zhidong; Kumamoto, Yasuaki; Shen, Chih Chiang; Hsu, Yu Te; Li, Lain-Jong; Saito, Riichiro; Kawata, Satoshi

    2015-01-01

    We present a comprehensive Raman scattering study of monolayer MoS2 with increasing laser excitation energies ranging from the near-infrared to the deep-ultraviolet. The Raman scattering intensities from the second-order phonon modes are revealed to be enhanced anomalously by only the ultraviolet excitation wavelength 354 nm. We demonstrate theoretically that such resonant behavior arises from a strong optical absorption that forms near the Γ point and of the band structure and an inter-valley resonant electronic scattering by the M-point phonons. These results advance our understanding of the double resonance Raman scattering process in low-dimensional semiconducting nanomaterials and provide a foundation for the technological development of monolayer MoS2 in the ultraviolet frequency range. © the Owner Societies 2015.

  15. Electron density distribution in BaPb1−xSbxO3 superconducting oxides studied by double nuclear magnetic resonance methods

    International Nuclear Information System (INIS)

    Piskunov, Yu. V.; Ogloblichev, V. V.; Arapova, I. Yu.; Sadykov, A. V.; Gerashchenko, A. P.; Verkhovskii, S. V.

    2011-01-01

    The effect of charge disorder on the formation of an inhomogeneous state of the electron system in the conduction band in BaPb 1−x Sb x O 3 superconducting oxides is investigated experimentally by NMR methods. The NMR spectra of 17 O are measured systematically, and the contributions from 17 O atoms with different cation nearest surroundings are identified. It is found that microscopic regions with an elevated spin density of charge carriers are formed within two coordination spheres near antimony ions. Nuclei of the superconducting phase of the oxide (regions with an elevated antimony concentration) microscopically distributed over the sample are detected in compounds with x = 0.25 and 0.33. Experiments in which a double resonance signal of the spin echo of 17 O- 207 Pb and 17 O- 121 Sb are measured in the metal phase of BaPb 1−x Sb x O 3 oxides are carried out for the first time. The constants of indirect heteronuclear spin-spin 17 O- 207 Pb interaction are determined as functions of the local Knight shift 207 Ks. The estimates of the constants of the indirect interaction between the nuclei of the nearest neighbors (O-Pb and Pb-Pb atoms) and analysis of evolution of the NMR spectra of 17 O upon a change in the antimony concentration are convincing evidence in favor of the development of a microscopically inhomogeneous state of the electron system in the metal phase of BaPb 1−x Sb x O 3 oxides.

  16. Repository design sensitivity study: Engineering study report

    International Nuclear Information System (INIS)

    1987-01-01

    A preliminary sensitivity study of the salt repository design has been performed to identify critical site and design parameters to help guide future site characterization and design optimization activities. The study considered the SCP-conceptual design at the Deaf Smith County site in Texas with the horizontal waste package emplacement mode as the base case. Relative to this base case, parameter variations were compared. Limited studies were performed which considered the vertical emplacement mode geometry. The report presents the reference data base and design parameters on which the study was based (including the range of parameters that might be expected). Detailed descriptions of the numerical modeling methods and assumptions are included for the thermal, thermomechanical and hydrogeological analyses. The impacts of parameter variations on the sensitivity of the rock mass response are discussed. Recommendations are provided to help guide site characterization activities and advanced conceptual design optimization activities. 47 refs., 119 refs., 22 tabs

  17. Civilian End Strength Study. Study Sponsor ODCSLOG.

    Science.gov (United States)

    1985-12-30

    Chief of Staff deferred action on the recommendations and requested a subsequent briefing with the following guidance. (1) Need to do more to take...Term Actions ... ..................... 38-39 ix CIVILIAN END STRENGTH STUDY Abstract This study examined the methodology by which the Army determines...DAPE-MBC) and COA ( DACA -OMP) has facilitated this process; an updated LOI, in draft, will clear up some of the problems identified in the test

  18. Drinking Game Studies

    DEFF Research Database (Denmark)

    Debus, Michael S.

    2016-01-01

    The paper examines research on drinking game participation from a game studies ontological perspective, covering definition, classification and problems with the, in the studies implied, underlying ontology of drinking games.......The paper examines research on drinking game participation from a game studies ontological perspective, covering definition, classification and problems with the, in the studies implied, underlying ontology of drinking games....

  19. Southeastern Cancer Study Group: breast cancer studies

    International Nuclear Information System (INIS)

    Smalley, R.V.; Bartolucci, A.A.; Moore, M.

    1983-01-01

    During the past 10 years, the Southeastern Cancer Study Group (SECSG) has been engaged in one major adjuvant study and three major advanced disease studies for patients with adenocarcinoma of the breast. The adjuvant study is demonstrating that six months of adjuvant CMF is the therapeutic equivalent of 12 months and that post-operative irradiation is of no added therapeutic benefit. In patients with advanced disease, a low dose 5 drug combination of CMFVP induces more objective responses than single agent 5FU, but improves survival only for those patients with liver metastases when compared to the sequential use of the same 5 single agents. The three drug combination, CAF, utilizing doxorubicin, induces more objective responses than low dose CMFVP, but it does not improve overall survival. The addition of a phase active combination, CAMELEON, (i.e., sequentially alternating therapy) of CAF has not improved the duration of disease control and survival for patients with liver metastases, lymphangitic and nodular lung metastases compared to CAF. Aggressive combination chemotherapeutic approaches to patients with advanced disease provide better and longer disease and tumor control but only marginal improvements in overall survival. Adding additional agents to a maximally tolerable regimen has not improved the therapeutic outcome

  20. Physics studies in Europe; a comparative study

    NARCIS (Netherlands)

    Steenstrup, S; dalle Rose, LFD; Jones, WG; Tugulea, L; van Steenwijk, FJ

    What are the differences and similarities between physics studies at different universities across Europe (here the definition of Europe is broad)? How much does a student have to work to obtain a degree in physics? Questions like those prompted EUPEN (European Physics Education Network) to make a

  1. Case Study Research Methodology

    Directory of Open Access Journals (Sweden)

    Mark Widdowson

    2011-01-01

    Full Text Available Commenting on the lack of case studies published in modern psychotherapy publications, the author reviews the strengths of case study methodology and responds to common criticisms, before providing a summary of types of case studies including clinical, experimental and naturalistic. Suggestions are included for developing systematic case studies and brief descriptions are given of a range of research resources relating to outcome and process measures. Examples of a pragmatic case study design and a hermeneutic single-case efficacy design are given and the paper concludes with some ethical considerations and an exhortation to the TA community to engage more widely in case study research.

  2. The Study of Algae

    Science.gov (United States)

    Rushforth, Samuel R.

    1977-01-01

    Included in this introduction to the study of algae are drawings of commonly encountered freshwater algae, a summary of the importance of algae, descriptions of the seven major groups of algae, and techniques for collection and study of algae. (CS)

  3. Current Research Studies

    Science.gov (United States)

    ... Success Home > Explore Research > Current Research Studies Current Research Studies Email Print + Share The Crohn’s & Colitis Foundation ... conducted online. Learn more about IBD Partners. Clinical Research Alliance The Clinical Research Alliance is a network ...

  4. FEMA DFIRM Study Info

    Data.gov (United States)

    Minnesota Department of Natural Resources — This table contains details about the study such as the study name, datum, projection, etc. There is normally only one record in this table for each Flood Insurance...

  5. Neutron beam studies

    International Nuclear Information System (INIS)

    Willis, B.T.M.; Apps, M.E.

    1979-01-01

    The report is in sections, entitled: metallurgy; reactor fuels; defect solid state and interatomic forces; surface studies; colloid, polymer and biological studies; glasses; energy-related materials; solid state physics and crystallography; instrumentation and experimental technique. (U.K.)

  6. Study of strange nuclei

    International Nuclear Information System (INIS)

    Chrien, R.E.

    1982-01-01

    A brief history of the discovery of hypernuclei is given and some recent hypernuclei studies are described. Topics include the study of p-shell hypernuclei, 12 C (K - , π - ) experiment, and hypernuclear gamma rays. 13 references

  7. Chemical Industry Bandwidth Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2006-12-01

    The Chemical Bandwidth Study provides a snapshot of potentially recoverable energy losses during chemical manufacturing. The advantage of this study is the use of "exergy" analysis as a tool for pinpointing inefficiencies.

  8. Critical Kinship Studies

    DEFF Research Database (Denmark)

    In recent decades the concept of kinship has been challenged and reinvigorated by the so-called “repatriation of anthropology” and by the influence of feminist studies, queer studies, adoption studies, and science and technology studies. These interdisciplinary approaches have been further...... developed by increases in infertility, reproductive travel, and the emergence of critical movements among transnational adoptees, all of which have served to question how kinship is now practiced. Critical Kinship Studies brings together theoretical and disciplinary perspectives and analytically sensitive...... in the Humanities and Social Sciences today. Critical Kinship Studies should be of particular interest to students and scholars in Anthropology, Sociology, Cultural Studies, Medical Humanities, Politics, Gender and Queer Studies and Globalization....

  9. 522 Postmarket Surveillance Studies

    Data.gov (United States)

    U.S. Department of Health & Human Services — The 522 Postmarket Surveillance Studies Program encompasses design, tracking, oversight, and review responsibilities for studies mandated under section 522 of the...

  10. Descriptive studies of Purepecha: Introductory study

    Directory of Open Access Journals (Sweden)

    Violeta Vázquez Rojas Maldonado

    2013-12-01

    Full Text Available Seven papers in this volume are the result of a collective project of linguistic description. This introduction offers a general background for such enterprise. It provides information about some sociolinguistic and grammatical aspects of the Purepecha language, a list of some recent studies on the language, it describes the orthographic conventions employed. We also provide details about the elicitation methodology and the demographic information of the language consultants.

  11. Study deep geothermal energy; Studie dypgeotermisk energi

    Energy Technology Data Exchange (ETDEWEB)

    Havellen, Vidar; Eri, Lars Sigurd; Andersen, Andreas; Tuttle, Kevin J.; Ruden, Dorottya Bartucz; Ruden, Fridtjof; Rigler, Balazs; Pascal, Christophe; Larsen, Bjoern Tore

    2012-07-01

    The study aims to analyze the potential energy with current technology, challenges, issues and opportunities for deep geothermal energy using quantitative analysis. It should especially be made to identify and investigate critical connections between geothermal potential, the size of the heating requirements and technical solutions. Examples of critical relationships may be acceptable cost of technology in relation to heating, local geothermal gradient / drilling depth / temperature levels and profitability. (eb)

  12. INTRODUCTION/ BACKGROUND OF STUDY

    African Journals Online (AJOL)

    user

    The study was carried out in Abia State. Five out ... study area and the farmers were more of women. ... Cassava utilization, as livestock feed, is very popular in the whole world, ... In order to relieve farmers from this problem of poor yield during harvesting, the .... Also majority (54.7 percent) of the cassava farmers in the study.

  13. Low frequency noise study.

    Science.gov (United States)

    2007-04-01

    This report documents a study to investigate human response to the low-frequency : content of aviation noise, or low-frequency noise (LFN). The study comprised field : measurements and laboratory studies. The major findings were: : 1. Start-of-takeof...

  14. STUDYING ON THE INTERNET

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    正Nowadays the Internet is more and more popular.I think it is a good way of learning. First,the Intemet enables people to study whenever and wherever it is convenient. They can also choose to study whatever they are interested in.However,a traditional school doesn't provide such great freedom.Students have to study given sub-

  15. Selling the Social Studies.

    Science.gov (United States)

    Girod, Gerald R.; Harmon, Gerald R.

    1987-01-01

    Maintains school-aged children would prefer not to study social studies. Presents several strategies to help encourage positive attitudes. Strategies include persuasion, reinforcement, enthusiasm, personalized contact. Stresses that negative attitudes must be changed in order for social studies to achieve its fundamental citizenship goals. (BR)

  16. Development of a new electron-RI colliding scheme for study of unstable nuclear structure

    International Nuclear Information System (INIS)

    Wakasugi, M.; Emoto, T.; Ishihara, M.; Koseki, T.; Ohnishi, T.; Suda, T.; Takeda, H.; Yano, Y.; Kurita, K.

    2004-01-01

    A new method of electron scattering experiment for unstable nuclei is proposed. In this method, the low energy ion beam is injected into the electron storage ring where the transverse potential well made by electron beam exists. The ion beam is three-dimensionally confined by applying longitudinal static mirror potential externally. The ion beam confined on the electron beam axis is regarded as the Self-Confining Radioactive Ion Target (SCRIPT). This idea originally comes from the ion trap phenomenon of the electron storage ring. For the electron scattering experiment, luminosity higher than 10 26 s -1 cm -2 is required for heavy nuclei. In order to test this idea, computer simulation is performed. Limit of the storage of positive charges, change of the ion valences caused by the collisions with the electrons, nuclear decays and capture of residual gas, other interactions and the luminosity are investigated. Demonstration of this idea is under way at the KSR storage ring of Kyoto University with the SCRIPT instrument equipped with forty built-in electrodes. It is expected that the number of ions accumulated and the luminosity of the collisions are about 10 6 and 2x10 25 s -1 cm -2 , respectively, at the electron beam energy of 100 MeV and current of 100 mA(max). (S. Funahashi)

  17. Studying Engineering Practice

    DEFF Research Database (Denmark)

    Buch, Anders

    2015-01-01

    The study of engineering practices has been the focus of Engineering Studies over the last three decades. Theses studies have used ethnographic and grounded methods in order to investigate engineering practices as they unfold in natural settings - in workplaces and engineering education. However......, engineering studies have not given much attention to conceptually clarifying what should be understood by 'engineering practices' and more precisely account for the composition and organization of the entities and phenomena that make up the practices. This chapter investigates and discusses how a 'practice...... will draw out some methodological consequences and discuss the ramifications of a practice theoretical approach for Engineering Studies....

  18. Mysore study: A study of suicide notes.

    Science.gov (United States)

    Namratha, P; Kishor, M; Sathyanarayana Rao, T S; Raman, Rajesh

    2015-01-01

    Suicide is one of the leading causes of preventable deaths. Recent data suggest South India as one of the regions with highest suicide rates in the world. In 2013, 134,799 people committed suicide in India according to the statistics released by the National Crime Records Bureau. Suicide note is one of the most important sources to understand suicide, which may be beneficial in suicide prevention. Studies on suicidal notes from this part of the world are sparse. The aim was to study the themes in suicide notes that might be useful in prevention strategies. A descriptive study of all suicide notes of those individuals who committed suicide between 2010 and 2013 available with Police Department, Mysore district was obtained and analyzed. A total of 22 suicide note were available. A majority of suicide note was in age group of 16-40 years (86%) and most were men (59%). All suicide notes were handwritten, the majority (70%) in regional language Kannada. Length of notes varied from just few words to few pages. Contents of suicide notes included apology/shame/guilt (80%), love for those left behind (55%) and instruction regarding practical affairs (23%). Most have blamed none for the act (50%). 23% mentioned that they are committing suicide to prove their innocence. 32% mentioned a last wish. The majority of suicidal note contained "guilt" which is a strong indicator of possible depression in deceased. Creating awareness about suicide among public and ensuring access to professionals trained in suicide prevention is need of the hour in this part of the world.

  19. Proceedings (Mathematical Sciences) SUBJECT INDEX

    Indian Academy of Sciences (India)

    . Divisor. The Jacobian of a nonorientable Klein sur- face, II. 51. Double resonance. Multiplicity of nontrivial solutions for elliptic equations with nonsmooth poten- tial and resonance at higher eigenvalues. 233. Dual. Quotient normed cones.

  20. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 113; Issue 3 .... Excess molar volumes and viscosities of binary mixtures of 1,2-diethoxyethane with chloroalkanes ... IR-UV double resonance spectroscopy in jet and ab initio calculation.

  1. The CAIRO4 study

    DEFF Research Database (Denmark)

    't Lam-Boer, Jorine; Mol, Linda; Verhoef, Cornelis

    2015-01-01

    stages of the disease. We here propose a randomized trial in order to demonstrate that resection of the primary tumour improves overall survival. METHODS/DESIGN: The CAIRO4 study is a multicentre, randomized, phase III study of the Dutch Colorectal Cancer Group (DCCG). Patients with synchronous...... objective of this study is to determine the clinical benefit in terms of overall survival of initial resection of the primary tumour. Secondary endpoints include progression free survival, surgical morbidity, quality of life and the number of patients requiring resection of the primary tumour in the control...... arm. DISCUSSION: The CAIRO4 study is a multicentre, randomized, phase III study that will assess the benefit of resection of the primary tumour in patients with synchronous metastatic CRC. TRIAL REGISTRATION: The CAIRO4 study is registered at clinicaltrials.gov (NCT01606098)....

  2. The modal study

    International Nuclear Information System (INIS)

    Cook, J.R.

    1988-01-01

    The term ''Modal Study'' refers to a research program conducted for the Nuclear Regulatory Commission (NRC) on the level of protection provided by NRC-certified packages during the shipment of spent nuclear fuel form U.S. power reactors. The objective of the study was to examine the response of the packages to actual highway and railway accident conditions. The Modal Study results show that NRC-certified spent fuel casks would perform their safety functions under severe, actual accident conditions. The study also explains how NRC's cask design conditions, which are expressed in engineering terms, relate to actual accident conditions, with which the public is more familiar. The Modal Study, along with other transportation studies, physical testing of casks, and the spent fuel shipment safety record confirm the view that casks provide a high level of public safety during spent fuel transport

  3. Nuclear Industry Family Study

    International Nuclear Information System (INIS)

    1993-01-01

    This is a copy of the U.K.A.E.A. Question and Answer brief concerning an epidemiological study entitled the Nuclear Industry Family Study, to investigate the health of children of AEA, AWE, and BNFL Workers. The study is being carried out by an independent team of medical research workers from the London School of Hygiene and Tropical Medicine, and the Imperial Cancer Research Fund. (UK)

  4. Doing Cultural Studies

    DEFF Research Database (Denmark)

    du Gay, Paul; Hall, Stuart; Janes, Linda

    What does the Walkman have to do with the 21st century? The long-awaited second edition of this classic textbook takes students on a journey between past and present, giving them the skills do to cultural analysis along the way. Through the notion of the 'circuit of culture', this book teaches st......' for cultural studies. It is an essential classic, reworked for today's students in cultural studies, media studies and sociology....

  5. Phase controlled rectifier study

    International Nuclear Information System (INIS)

    Bronner, G.; Murray, J.G.

    1976-03-01

    This report introduces the results of an engineering study incorporating a computer program to determine the transient and steady-state voltage and current wave shapes for a 12-pulse rectifier system. Generally, rectifier engineering studies are completed by making simplified assumptions and neglecting many circuit parameters. The studies incorporate the 3-phase AC parameters including nonlinear source or generator, 3-winding transformer impedances, and shunt and series capacitors. It includes firing angle control, and DC filter circuits with inductive loads

  6. Innovation and Entrepreneurship Studies

    DEFF Research Database (Denmark)

    Landström, Hans; Åström, Fredrik; Harirchi, Gouya

    2015-01-01

    -of-the-art” books in entrepreneurship studies and eleven books in innovation studies. The chapters in these “state-of-the-art” books are written by experts within the field, and it can be assumed that the most frequently cited references in these chapters represent “core knowledge” in entrepreneurship...... innovation and entrepreneurship studies can be considered as two fields or parts of a single broader scientific field, sharing and contributing to the same knowledge base? The studies by Fagerberg et al. and Landström et al. are based on two unique databases consisting of all references in twelve “state...

  7. Project management case studies

    CERN Document Server

    Kerzner, Harold R

    2013-01-01

    A new edition of the most popular book of project management case studies, expanded to include more than 100 cases plus a ""super case"" on the Iridium Project Case studies are an important part of project management education and training. This Fourth Edition of Harold Kerzner''s Project Management Case Studies features a number of new cases covering value measurement in project management. Also included is the well-received ""super case,"" which covers all aspects of project management and may be used as a capstone for a course. This new edition:Contains 100-plus case studies drawn from re

  8. Information society studies

    CERN Document Server

    Duff, Alistair S

    2013-01-01

    We are often told that we are ""living in an information society"" or that we are ""information workers."" But what exactly do these claims mean, and how might they be verified? In this important methodological study, Alistair S. Duff cuts through the rhetoric to get to the bottom of the ""information society thesis."" Wide-ranging in coverage, this study will be of interest to scholars in information science, communication and media studies and social theory. It is a key text for the newly-unified specialism of information society studies, and an indispensable guide to the future of this disc

  9. Human exploration mission studies

    Science.gov (United States)

    Cataldo, Robert L.

    1989-01-01

    The Office of Exploration has established a process whereby all NASA field centers and other NASA Headquarters offices participate in the formulation and analysis of a wide range of mission strategies. These strategies were manifested into specific scenarios or candidate case studies. The case studies provided a systematic approach into analyzing each mission element. First, each case study must address several major themes and rationale including: national pride and international prestige, advancement of scientific knowledge, a catalyst for technology, economic benefits, space enterprise, international cooperation, and education and excellence. Second, the set of candidate case studies are formulated to encompass the technology requirement limits in the life sciences, launch capabilities, space transfer, automation, and robotics in space operations, power, and propulsion. The first set of reference case studies identify three major strategies: human expeditions, science outposts, and evolutionary expansion. During the past year, four case studies were examined to explore these strategies. The expeditionary missions include the Human Expedition to Phobos and Human Expedition to Mars case studies. The Lunar Observatory and Lunar Outpost to Early Mars Evolution case studies examined the later two strategies. This set of case studies established the framework to perform detailed mission analysis and system engineering to define a host of concepts and requirements for various space systems and advanced technologies. The details of each mission are described and, specifically, the results affecting the advanced technologies required to accomplish each mission scenario are presented.

  10. Study Groups in Denmark

    DEFF Research Database (Denmark)

    Hjorth, Poul G.

    2007-01-01

    Since 1998 European Study Groups have been held in Denmark, and Danish companies from LEGO and NOVO to very small high-tech firms have participated. I briefly describe the history, the organisation and the format of the Danish Study Groups, and highlight a few problem solutions.......Since 1998 European Study Groups have been held in Denmark, and Danish companies from LEGO and NOVO to very small high-tech firms have participated. I briefly describe the history, the organisation and the format of the Danish Study Groups, and highlight a few problem solutions....

  11. Film studies the basics

    CERN Document Server

    Villarejo, Amy

    2013-01-01

    Film Studies: The Basics is a compelling guide to the study of cinema in all its forms. This second edition has been thoroughly revised and updated to take account of recent scholarship, the latest developments in the industry and the explosive impact of new technologies. Core topics covered include:   The history, technology and art of cinema Theories of stardom, genre and film-making The movie industry from Hollywood to Bollywood Who does what on a film set   Complete with film stills, end-of-chapter summaries and a substantial glossary, Film Studies: The Basics is the ideal introduction to those new to the study of cinema.

  12. Towards Marxian Internet Studies

    Directory of Open Access Journals (Sweden)

    Christian Fuchs

    2012-05-01

    Full Text Available This article gives an overview of example approaches of Critical Internet Studies and points out key concepts of this field. Critical Cyberculture Studies and Critical Political Economy/Critical Theory of the Internet are identified as two approaches in Critical Internet Studies. The paper also discusses the role of 11 Marxian concepts for Critical Internet Studies. Marxian concepts that have been reflected in Critical Internet Studies include: dialectics, capitalism, commodification, surplus value/exploitation/alienation/class, globalization, ideology, class struggle, commons, public sphere, communism, and aesthetics. The paper points out the importance of explicitly acknowledging the importance of Karl Marx’s thinking in Critical Internet Studies. Marx’s concepts are today frequently used implicitly, without acknowledging and engaging with their roots. A critique of the approach of “Critical” Cyberculture Studies is advanced. This approach is compared to the approaches of Critical Theory and Critical Political Economy of the Internet. The difference between these two approaches reflects the debate about class exploitation and non-class domination between Cultural Studies and Critical Political Economy in Media and Communication Studies.

  13. Studies in chemical dynamics

    International Nuclear Information System (INIS)

    Kuppermann, A.

    1978-01-01

    Progress made in the following studies is reported: low-energy electron scattering; variable-angle photoelectron spectroscopy; laser photochemistry and spectroscopy; and collisions in crossed molecular beams

  14. Excited states

    CERN Document Server

    Lim, Edward C

    1974-01-01

    Excited States, Volume I reviews radiationless transitions, phosphorescence microwave double resonance through optical spectra in molecular solids, dipole moments in excited states, luminescence of polar molecules, and the problem of interstate interaction in aromatic carbonyl compounds. The book discusses the molecular electronic radiationless transitions; the double resonance techniques and the relaxation mechanisms involving the lowest triplet state of aromatic compounds; as well as the optical spectra and relaxation in molecular solids. The text also describes dipole moments and polarizab

  15. Simulation in International Studies

    Science.gov (United States)

    Boyer, Mark A.

    2011-01-01

    Social scientists have long worked to replicate real-world phenomena in their research and teaching environments. Unlike our biophysical science colleagues, we are faced with an area of study that is not governed by the laws of physics and other more predictable relationships. As a result, social scientists, and international studies scholars more…

  16. Ca-48 metabolism studies

    International Nuclear Information System (INIS)

    Van der Merwe, D.G.

    1987-03-01

    Calcium metabolism has been studied in depth physiologically and is a relatively well-understood element in biochemistry and medicine. There is still only restricted knowledge of the metabolic fate of calcium in normal and abnormal paediatric subjects. The latter is partially owing to inadequate techniques for tracing and modelling calcium pathways in children. The advent of radioactive tracers has unquestionably enhanced medical research and improved the quality of many metabolic studies. The present study was aimed at the development, promotion and justification of a new tracer technique using the stable isotope, calcium-48. The obvious advantages of such a technique are its harmlessness tothe subject, its applicability to both short- and long-term studies as well as its usefulness to the study for which it was originally motivated, viz research defining the actual relationship between a calcium-deficient diet and the occurrence of rickets in rural Black children in South Africa. Exploratory instrumental analyses were performed specifically with serum samples. This proved successful enough to develop a less specific pre-concentration technique which improved the sensitivity and reduces the cost of doing calcium-48 metabolism studies. The results of a simple metabolic study are presented whereby the scope of the technique is demonstrated in a real situation. The possibilities and limitations of double-isotope metabolic studies are discussed, particularly with regard to strontium as the second tracer

  17. Journal of Cultural Studies

    African Journals Online (AJOL)

    The Journal of Cultural Studies was established in 1999 as an independent tool for research development in Africa. It is published by the Nigerian Group for the Study of African ... Sexual Harassment in the Workplace: A Case for Linguistic and Sexual Politics? EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT ...

  18. Designing a Language Study.

    Science.gov (United States)

    Brown, James Dean

    Some issues in the design of classroom research on second language teaching are discussed, with the intention of helping the researcher avoid conceptual pitfalls that may cripple the study later in the process. This begins with an examination of concerns in sampling, including definition of a population to be studied, alternative sampling…

  19. Jabiluka environmental studies

    Energy Technology Data Exchange (ETDEWEB)

    Morley, A.W.; Koontz, D.V.; Sanderson, N.T. (Pancontinental Mining Ltd., Sydney (Australia))

    1984-02-01

    Environmental baseline studies associated with development of the Jabiluka uranium deposits are described. Some basic characteristics of the area local to the deposits are reported and a brief explanation is provided of the nature of, and philosophy behind the environmental studies. The major findings from this program are discussed.

  20. Jabiluka environmental studies

    International Nuclear Information System (INIS)

    Morley, A.W.; Koontz, D.V.; Sanderson, N.T.

    1984-01-01

    Environmental baseline studies associated with development of the Jabiluka uranium deposits are described. Some basic characteristics of the area local to the deposits are reported and a brief explanation is provided of the nature of, and philosophy behind the environmental studies. The major findings from this program are discussed. (author)

  1. Aquatic biology studies

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Aquatic biology studies focused on studying the hydrothermal effects of Par Pond reservoir on periphyton, plankton, zooplankton, macrophytes, human pathogens, and microbial activity; the variability between the artificial streams of the Flowing Streams Laboratory and Upper Three Runs Creek; and the bacterial production of methane in Savannah River Plant aquatic systems

  2. Mirror hybrid reactor studies

    International Nuclear Information System (INIS)

    Bender, D.J.

    1978-01-01

    The hybrid reactor studies are reviewed. The optimization of the point design and work on a reference design are described. The status of the nuclear analysis of fast spectrum blankets, systems studies for fissile fuel producing hybrid reactor, and the mechanical design of the machine are reviewed

  3. Pacific Studies: Quo Vadis?

    Directory of Open Access Journals (Sweden)

    Anne Holden Rønning

    2014-02-01

    Full Text Available Looking back to the past this paper discusses why Pacific studies and in particular Australasian studies became an area of interest in tertiary education in Europe. What subject areas initiated these studies, and how do past legacies shape the present? With cutbacks in higher education over the past two decades the future of interdisciplinary studies and the humanities looks bleak. At the same time due to global business and increased political communication across borders there is a vibrant interest in and need for such studies among businesses and students. For most Europeans the literature of settler countries, with their European legacy, makes access to ways of thought and culture easier than studies of countries with other mythological backgrounds. In today’s multicultural environment such studies can provide knowledge for an understanding of other cultures and increase tolerance of the ‘other’. Area studies have relevance to our situation in Europe with increased migrancy, not least as a result of Schengen and EU regulations.

  4. Missouri airport investment study

    Science.gov (United States)

    The studys purpose is to provide MoDOT with insight to the potential ROI for airport : investments in terms of economic development. To do so, this study addresses two central : objectives: first, an approach to evaluate airport investments; and s...

  5. Energy conversion alternatives study

    Science.gov (United States)

    Shure, L. T.

    1979-01-01

    Comparison of coal based energy systems is given. Study identifies and compares various advanced energy conversion systems using coal or coal derived fuels for baselaoad electric power generation. Energy Conversion Alternatives Study (ECAS) reports provede government, industry, and general public with technically consistent basis for comparison of system's options of interest for fossilfired electric-utility application.

  6. The Study of Butterflies

    Indian Academy of Sciences (India)

    The Study of Butterflies. 3. Intra-specific ... study of chitinous parts of the genitalia, especially of males proved a .... not known to affect mating habits in any way. We now .... such random interactions as well as modifications caused by external ...

  7. Theorizing Iberian Studies

    Science.gov (United States)

    Newcomb, Robert Patrick

    2015-01-01

    A growing number of scholars invested in Iberian Studies are asking how peninsular literary and cultural studies might be reimagined, and reinvigorated, by placing the Spanish and Portuguese canons into critical dialogue with each other, and with Galician, Catalan, Basque/Euskadi, and Latin American and North African immigrant writers, cultural…

  8. Prolactinomas : clinical studies

    NARCIS (Netherlands)

    Kars, Marleen

    2008-01-01

    Prolactinoma are treated with dopamine agonists, which are effective in reducing prolactin and tumor size. Studies reporting clinical and radiological outcome are scarce. The study described in chapter 2, assesses long-term outcome in patients treated with dopamine agonists for macroprolactinoma. An

  9. Fusion energy studies

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Current experimental efforts are aimed toward developing cryosorption vacuum pumps for removing unburned fuel and impurities from the plasma, studying deep-bed sorption pumps for roughing and transfer operations, investigating methods for recovery of tritium bred in blankets of lithium or lithium alloys, and studying containment of tritium that permeates metal walls

  10. Designing satisfaction studies

    DEFF Research Database (Denmark)

    Kristensen, Kai; Eskildsen, Jacob Kjær

    2007-01-01

    In the effect sampling method, presentation of researcher, the intro text, the order of questions in the questionnaire along with the number of categories in the rating scale is tested in relation to the design of satisfaction studies. Based on the analyses specific recommendations for designing...... satisfaction studies are given....

  11. American Studies in Transition

    DEFF Research Database (Denmark)

    Nye, David

    Papers first given at a conference the previous year in Fåborg, Denmark, with a dual focus on 20th century America and new methods in American Studies.......Papers first given at a conference the previous year in Fåborg, Denmark, with a dual focus on 20th century America and new methods in American Studies....

  12. Studies of Personality Disorders

    DEFF Research Database (Denmark)

    Ronningstam, Elsa; Simonsen, Erik; Oldham, John M

    2014-01-01

    The past 25 years have shown major advances in the studies of personality disorders. This collaborative article by the presidents, past and present, of ISSPD reflects on the progress within several significant areas of studies, i.e., assessment, neuroscience, treatment, prevention, advocacy...

  13. Geothermal studies in China

    International Nuclear Information System (INIS)

    Wang Ji-Yang; Chen Mo-Xiang; Wang Ji-An; Deng Xiao; Wang Jun; Shen Hsien-Chieh; Hsiung Liang-Ping; Yan Shu-Zhen; Fan Zhi-Cheng; Liu Xiu-Wen

    1981-01-01

    Geothermal studies have been conducted in China continuosly since the end of the 1950's with renewed activity since 1970. Three areas of research are defined: (1) fundamental theoretical research of geothermics, including subsurface temperatures, terrestrial heat flow and geothermal modeling; (2) exploration for geothermal resources and exploitation of geothermal energy; (3) geothermal studies in mines. (orig./ME)

  14. Lesson study i Danmark?

    DEFF Research Database (Denmark)

    Mogensen, Arne

    2009-01-01

    Der beskrives et japansk lesson study forløb, og det diskuteres i hvilket omfang, de gode japanske erfaringer kan overføres til dansk matematikundervisning.......Der beskrives et japansk lesson study forløb, og det diskuteres i hvilket omfang, de gode japanske erfaringer kan overføres til dansk matematikundervisning....

  15. Radiopharmaceuticals for renal studies

    International Nuclear Information System (INIS)

    Verdera, Silvia

    1994-01-01

    Between the diagnostic techniques using radiopharmaceuticals in nuclear medicine it find renal studies.A brief description about renal glomerular filtration(GFR) and reliability renal plasma flux (ERPF),renal blood flux measurement agents (RBF),renal scintillation agents and radiation dose estimates by organ physiology was given in this study.tabs

  16. Memetics and Translation Studies

    OpenAIRE

    Andrew, Chesterman

    2000-01-01

    Translation Studies is a branch of memetics. This is a claim, a hypothesis. More specifically, it is an interpretive hypothesis: I claim that Translation Studies can be thus interpreted, and that this is a useful thing to do because it offers a new and beneficial way of understanding translation.

  17. Managerial Accounting. Study Guide.

    Science.gov (United States)

    Plachta, Leonard E.

    This self-instructional study guide is part of the materials for a college-level programmed course in managerial accounting. The study guide is intended for use by students in conjuction with a separate textbook, Horngren's "Accounting for Management Control: An Introduction," and a workbook, Curry's "Student Guide to Accounting for Management…

  18. Studies Highlight Biodiesel's Benefits

    Science.gov (United States)

    , Colo., July 6, 1998 — Two new studies highlight the benefits of biodiesel in reducing overall air Energy's National Renewable Energy Laboratory (NREL) conducted both studies: An Overview of Biodiesel and Petroleum Diesel Life Cycles and Biodiesel Research Progress, 1992-1997. Biodiesel is a renewable diesel

  19. Multimodality in organization studies

    DEFF Research Database (Denmark)

    Van Leeuwen, Theo

    2017-01-01

    This afterword reviews the chapters in this volume and reflects on the synergies between organization and management studies and multimodality studies that emerge from the volume. These include the combination of strong sociological theorizing and detailed multimodal analysis, a focus on material...

  20. Luminescence study of spodumene

    International Nuclear Information System (INIS)

    Isotani, S.; Fujii, A.T.; Antonini, R.; Pontuschka, W.M.; Rabani, S.R.; Furtado, W.W.

    1990-02-01

    A comparative study is made of the luminescence of five kinds of spodumene from Minas Gerais, Brazil, studied previously by optical absorption spectroscopy. Natural gemstones are used which, in the course of the experiments, were irradiated with X-rays. (L.C.) [pt

  1. Methods of Studying Persons.

    Science.gov (United States)

    Heinemann, Allen W.; Shontz, Franklin C.

    Conventional research strategies typically emphasize behavior-determining tendencies so strongly that the person as a whole is ignored. Research strategies for studying whole persons focus on symbolic structures, formulate specific questions in advance, study persons one at a time, use individualized measures, and regard participants as expert…

  2. Explaining Kansei design studies

    NARCIS (Netherlands)

    Levy, P.D.; Vakamori, S.; Yamanaka, T.

    2008-01-01

    Within the last thirty years, Kansei studies have become an important field of research in Japan. More recently, foreign researchers have become more and more interested in understating the approach, despite the difficulties related to the cultural dimension of Kansei and Kansei studies. The aim of

  3. Censorship in Social Studies.

    Science.gov (United States)

    Seiferth, Berniece B.

    In order to determine how much censorship was taking place in Illinois social studies classes, 200 principals were asked to respond to a questionnaire regarding censorship of teaching methods and social studies textbooks. The principals were asked to respond to the following topics concerning the degree of censorship encountered for each item:…

  4. Archives: African Studies Monographs

    African Journals Online (AJOL)

    Archives: African Studies Monographs. Journal Home > Archives: African Studies Monographs. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives. 1 - 5 of 5 Items. 2007. Vol 8 (2007) ...

  5. Critical Digital Tourism Studies

    DEFF Research Database (Denmark)

    Gyimóthy, Szilvia; Munar, Ana María

    2013-01-01

    This paper advocates the need for a critical and cross-disciplinary research agenda on the field of digital technologies and tourism. The changing virtual landscape of tourism has received increased attention by tourism scholars. However, contemporary studies on information technologies (IT......) are approached mostly from a business administration perspective and informed by conceptual frameworks developed in management and marketing. IT studies in tourism are still at a stage similar to the first advocacy phase of tourism research in general (Jafari, 1990) and are seldom inspired by relevant...... to studying digital socio-technical systems and virtual mediation in tourism. Critical Digital Tourism Studies opens a new cross-disciplinary field where the sociality of virtual tourism interactions is examined (entailing the study of structures, social rules, ideologies, power relations, sustainability...

  6. Hanford groundwater scenario studies

    International Nuclear Information System (INIS)

    Arnett, R.C.; Gephart, R.E.; Deju, R.A.; Cole, C.R.; Ahlstrom, S.W.

    1977-05-01

    This report documents the results of two Hanford groundwater scenario studies. The first study examines the hydrologic impact of increased groundwater recharge resulting from agricultural development in the Cold Creek Valley located west of the Hanford Reservation. The second study involves recovering liquid radioactive waste which has leaked into the groundwater flow system from a hypothetical buried tank containing high-level radioactive waste. The predictive and control capacity of the onsite Hanford modeling technology is used to evaluate both scenarios. The results of the first study indicate that Cold Creek Valley irrigationis unlikely to cause significant changes in the water table underlying the high-level waste areas or in the movement of radionuclides already in the groundwater. The hypothetical tank leak study showed that an active response (in this case waste recovery) can be modeled and is a possible alternative to passive monitoring of radionuclide movement in the unlikely event that high-level waste is introduced into the groundwater

  7. The bismuth miners study

    International Nuclear Information System (INIS)

    Grosche, B.; Kreuzer, M.; Kreisheimer, M.; Schnelzer, M.; Tschense, A.; Gottschalk, K.

    2005-01-01

    The Federal Radiation Protection Office carried out a retrospective cohort study on some 60,000 former employees of the SAG/SDAG Wismut. The purpose of the study was to validate the radon-related risk of acquiring lung cancer previously calculated from 11 jointly evaluated studies among miners on the basis of an independent, homogeneous data record of comparable size. A further goal was to study the risk of acquiring extrapulmonal tumours. This paper only briefly describes the sampling, design and methods used in the study, as these were already presented during the Radon Status Talks. The first follow-up on the cohort was completed in 2003. Around this time a job exposure matrix (JEM) suitable for scientific inquiries was made available by the professional miners' association and the roof organisation of professional trade associations (HVBG). This paper is the first to report on the outcome of the risk analysis in direct comparison with the results found by BEIR

  8. Single Policy Study

    DEFF Research Database (Denmark)

    Kronsell, Annica; Manners, Ian James

    2015-01-01

    Single policy studies are the most common form of European Union (EU) research. Single policy studies are widely used to understand the role of the EU in a wide variety of sectors, together with their development over time, and often offer public policy prescriptions. This chapter discusses...... the relevance of single policy studies in EU research and give examples of how such research can be designed and carried out. The chapter reviews three examples of single policy studies using different methods based on EU environmental policy, the EU biofuels directive, and the EU Common Security and Defence...... Policy (CSDP). The examples are illustrative of how single policy studies can be designed to use different approaches in the analysis: multiple streams approach to policy-making; a comparative hypothesis testing; and feminist institutional theory....

  9. International user studies

    DEFF Research Database (Denmark)

    Nielsen, Lene; Madsen, Sabine; Jensen, Iben

    In this report, we present the results of a research project about international user studies. The project has been carried out by researchers from the Center for Persona Research and –Application, The IT University in Copenhagen and the Department of Learning and Philosophy, Aalborg University...... in Sydhavnen, and it is funded by InfinIT. Based on a qualitative interview study with 15 user researchers from 11 different companies, we have investigated how companies collect and present data about users on international markets. Key findings are: Companies do not collect data about end users in all...... the countries/regions they operate in. Instead, they focus on a few strategic markets. International user studies tend to be large-scale studies that involve the effort of many both internal and external/local human resources. The studies typically cover 2-4 countries/regions and many end users in each country...

  10. Effective Physics Study Habits

    Science.gov (United States)

    Zettili, Nouredine

    2011-04-01

    We discuss the methods of efficient study habits and how they can be used by students to help them improve learning physics. In particular, we deal with ideas pertaining to the most effective techniques needed to help students improve their physics study skills. These ideas were developed as part of Project IMPACTSEED (IMproving Physics And Chemistry Teaching in SEcondary Education), an outreach grant funded by the Alabama Commission on Higher Education. This project is motivated by a major pressing local need: A large number of high school physics teachers teach out of field. In the presentation, focus on topics such as the skills of how to develop long term memory, how to improve concentration power, how to take class notes, how to prepare for and take exams, how to study scientific subjects such as physics. We argue that the student who conscientiously uses the methods of efficient study habits will be able to achieve higher results than the student who does not; moreover, a student equipped with the proper study skills will spend much less time to learn a subject than a student who has no good study habits. The underlying issue here is not the quantity of time allocated to the study efforts by the student, but the efficiency and quality of actions. This work is supported by the Alabama Commission on Higher Education as part of IMPACTSEED grant.

  11. Metabolomic Studies in Drosophila.

    Science.gov (United States)

    Cox, James E; Thummel, Carl S; Tennessen, Jason M

    2017-07-01

    Metabolomic analysis provides a powerful new tool for studies of Drosophila physiology. This approach allows investigators to detect thousands of chemical compounds in a single sample, representing the combined contributions of gene expression, enzyme activity, and environmental context. Metabolomics has been used for a wide range of studies in Drosophila , often providing new insights into gene function and metabolic state that could not be obtained using any other approach. In this review, we survey the uses of metabolomic analysis since its entry into the field. We also cover the major methods used for metabolomic studies in Drosophila and highlight new directions for future research. Copyright © 2017 by the Genetics Society of America.

  12. Decontamination solution development studies

    International Nuclear Information System (INIS)

    Allen, R.P.; Fetrow, L.K.; Kjarmo, H.E.; Pool, K.H.

    1993-09-01

    This study was conducted for the Westinghouse Hanford Company (WHC) by Pacific Northwest Laboratory (PNL) as part of the Hanford Grout Technology Program (HGTP). The objective of this study was to identify decontamination solutions capable of removing radioactive contaminants and grout from the Grout Treatment Facility (GTF) process equipment and to determine the impact of these solutions on equipment components and disposal options. The reference grout used in this study was prepared with simulated double-shell slurry feed (DSSF) and a dry blend consisting of 40 wt % limestone flour, 28 wt % blast furnace slag, 28 wt % fly ash, and 4 wt % type I/II Portland cement

  13. Teaching Secondary Social Studies

    Directory of Open Access Journals (Sweden)

    Colin Everett

    2018-03-01

    Full Text Available Review of the book, instructional strategies for middle and high school social studies: Methods, assessment, and classroom management, by Bruce E. Larson. The book has two goals: It situates the learning of social studies within the broader developmental context of learning and also focuses on “Instructional Strategies.” “Instructional Strategies for Middle and High School Social Studies: Methods, Assessment, and Classroom Management.” 2nd Edition. By Bruce E. Larson. New York: Routledge, 2017. ISBN: 978-1-138-84678-4

  14. Motivations of parametric studies

    International Nuclear Information System (INIS)

    Birac, C.

    1988-01-01

    The paper concerns the motivations of parametric studies in connection with the Programme for the Inspection of Steel Components PISC II. The objective of the PISC II exercise is to evaluate the effectiveness of current and advanced NDT techniques for inspection of reactor pressure vessel components. The parametric studies were initiated to determine the influence of some parameters on defect detection and dimensioning, and to increase the technical bases of the Round Robin Tests. A description is given of the content of the parametric studies including:- the effect of the defects' characteristics, the effect of equipment characteristics, the effect of cladding, and possible use of electromagnetic techniques. (U.K.)

  15. Tokamak reactor studies

    International Nuclear Information System (INIS)

    Baker, C.C.

    1981-01-01

    This paper presents an overview of tokamak reactor studies with particular attention to commercial reactor concepts developed within the last three years. Emphasis is placed on DT fueled reactors for electricity production. A brief history of tokamak reactor studies is presented. The STARFIRE, NUWMAK, and HFCTR studies are highlighted. Recent developments that have increased the commercial attractiveness of tokamak reactor designs are discussed. These developments include smaller plant sizes, higher first wall loadings, improved maintenance concepts, steady-state operation, non-divertor particle control, and improved reactor safety features

  16. [Case and studies].

    Science.gov (United States)

    Schubert, András

    2015-11-15

    Case studies and case reports form an important and ever growing part of scientific and scholarly literature. The paper deals with the share and citation rate of these publication types on different fields of research. In general, evidence seems to support the opinion that an excessive number of such publications may negatively influence the impact factor of the journal. In the literature of scientometrics, case studies (at least the presence of the term "case study" in the titles of the papers) have a moderate share, but their citation rate is practically equal to that of other publication types.

  17. Nuclear material shipment study

    International Nuclear Information System (INIS)

    Shepherd, E.W.

    1980-01-01

    The Radioactive Material Transport Assessment Study is expected to provide a flexible set of capabilities and useful information to the public, industry and government users by using a system design to assure obtaining high quality data from selected industry sources at acceptable cost. It is expected that the shipping record approach coupled with an efficient sampling strategy will accomplish this. The study is also designed to yield analytical capabilities and statistical output to serve public, industry and government users. The information provided by the study will make a valuable contribution to environmental and accident risk assessment, policy development and operational planning and management activities

  18. Border region studies

    DEFF Research Database (Denmark)

    Makkonen, Teemu; Williams, Allan

    2016-01-01

    The contemporary conditions of academic capitalism exert pressures on researchers to avoid ‘peripheral’ journals and ‘unfashionable’ topics. Here an attempt is made to shed light onto the structure of one such ‘offbeat’ field, namely ‘border region studies’, by discussing its geographical...... distribution, key themes, significance and impact. The review suggests that border region studies can be considered a significant and important ‘branch’ of regional studies, which accounts for a small but increasing proportion of regional studies research particularly in Europe and North America. Four main...

  19. Building Transdisciplinary Environmental Studies

    DEFF Research Database (Denmark)

    Holm, Jesper

    We will in this paper approach the challenge of building integrated environmental studies by presenting a crude frame of analysis which take into account both the physical aspects and the social-discursive articulations of environmental problems. This framework partly mirrors the approach of our...... department (Dept. of Environment, Technology and Social Studies, Roskilde University), and has originally in another version been presented in the book “Miljøregulering - tværvidenskabelige studier (Environmental Regulation. Interdisciplinary Studies)” (Holm, Kjærgård & Pedersen eds. 1997, in Danish) written...

  20. Plutonium storage study

    International Nuclear Information System (INIS)

    1979-01-01

    This Spanish study gives a more detailed analysis of a possible store for plutonium oxide. The capacity of the store is assumed to be 30 t Pu and the minimum storage time 2 years. The study includes a general description of the store and its design philosophy; comments on the quality and properties of the material stored; a detailed criticality study and comments on gas and heat generation and shielding requirements; and a brief cost evaluation. Costs are estimated to be about $110/kg PuO 2 /year

  1. American Studies in Romania

    Directory of Open Access Journals (Sweden)

    Ioana Luca

    2006-01-01

    Full Text Available American Studies at the University of BucharestThe idea of teaching American Studies and founding a program in American Studies was first voiced in the long meetings of faculty and students held at the University of Bucharest soon after the collapse of the communist regime. The proposal was one of many that reflected the spirit of reform and hope for radical changes at the outset of Romania’s transition to democracy. The absence of institutional structures other than English departments and t...

  2. Study of copper fluorination

    International Nuclear Information System (INIS)

    Gillardeau, J.

    1967-02-01

    This report deals with the action of fluorine on copper. Comprehensive descriptions are given of the particular technological methods and of the preparation of the reactants. This fluorination reaction has been studied at medium and low fluorine pressures. A nucleation and growth phenomenon is described. The influence of a pollution of the gas phase on the fluorination process is described. The solid-state reaction between cupric fluoride and cooper has also been studied. A special study has been made of the growth of copper deposits by thermal decomposition of gaseous fluorides. (author) [fr

  3. Pavement Subgrade Performance Study

    DEFF Research Database (Denmark)

    Zhang, Wei; Ullidtz, Per; Macdonald, Robin

    1998-01-01

    The report describes the second test in the Danish Road Testing Machine (RTM) under the International Pavement Subgrade Performance Study. Pavement response was measured in different layers, and compared to different theroretical values. Performance in terms of plastic strains, rutting...

  4. Optimum study designs.

    Science.gov (United States)

    Gu, C; Rao, D C

    2001-01-01

    Because simplistic designs will lead to prohibitively large sample sizes, the optimization of genetic study designs is critical for successfully mapping genes for complex diseases. Creative designs are necessary for detecting and amplifying the usually weak signals for complex traits. Two important outcomes of a study design--power and resolution--are implicitly tied together by the principle of uncertainty. Overemphasis on either one may lead to suboptimal designs. To achieve optimality for a particular study, therefore, practical measures such as cost-effectiveness must be used to strike a balance between power and resolution. In this light, the myriad of factors involved in study design can be checked for their effects on the ultimate outcomes, and the popular existing designs can be sorted into building blocks that may be useful for particular situations. It is hoped that imaginative construction of novel designs using such building blocks will lead to enhanced efficiency in finding genes for complex human traits.

  5. Accelerator research studies

    International Nuclear Information System (INIS)

    1993-01-01

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the second year of a three-year funding cycle. The program consists of the following three tasks: TASK A, ''Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams,'' (P.I., M. Reiser); TASK B, ''Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams,'' (Co-P.I.'s, W.W. Destler, M. Reiser, M.J. Rhee, and C.D. Striffler); TASK C, ''Study of a Gyroklystron High-Power Microwave Source for Linear Colliders,'' (Co-P.I.'s, V.L. Granatstein, W. Lawson, M. Reiser, and C.D. Striffler). In this report we document the progress that has been made during the past year for each of the three tasks

  6. Exploratory studies, 1988

    International Nuclear Information System (INIS)

    1989-05-01

    This report discusses the following topics: accelerator physics for the ALS; SSC support; machine investigations; mathematical techniques in particle dynamics; APIARY: B-factory studies; and two-beam accelerators and bright electron sources

  7. Accelerator research studies

    International Nuclear Information System (INIS)

    1990-01-01

    This progress report for the Accelerator Research Studies program at the University of Maryland covers the second year (June 1, 1989 to May 31, 1990) of the current three-year contract period from June 1, 1988 to May 31, 1991, funded by the Department of Energy under Contract No. AC05-85ER40216. The research program is divided into three separate tasks, as follows: the study of Transport and Longitudinal Compression of Intense, High-Brightness Beams; the study of Collective Ion Acceleration by Intense Electron Beams and Pulse-Powered Plasma Focus; the study of Microwave Sources and Parameter Scaling for High-Frequency Linacs. This report consists of three sections in which the progress for each task is documented separately. An introduction and synopsis is presented at the beginning of the progress report for each task

  8. Geomembrane special study

    International Nuclear Information System (INIS)

    1988-07-01

    The objective of the Geomembrane Special Study was to asses the suitability of geomembranes in Uranium Mill Tailings Remedial Action (UMTRA) Project pile designs. Geomembranes, also called flexible membrane liners, are made of polymer resins and are thermoplastic materials. Part of the special study was to evaluate regulatory compliance and acceptability issues. This study was proposed because of the extensive use of geomembranes in hazardous waste site remedial actions and their accepted use in Resource Conservation and Recovery Act (RCRA) cells as both covers and liners to limit infiltration, or as part of leachate collection systems. This study has reviewed the recent geomembrane literature focusing on: (1) longevity; (2) performance; (3) constructibility; and (4) quality control/quality assurance considerations. In addition to these technical considerations, regulatory compliance and acceptability concerns were also evaluated. This report describes the results of the literature review, including correspondence with manufacturers, resin producers, experts in the field, and long-term major users. 12 refs., 2 tabs

  9. STUDYING BUSINESS CYCLES SYNCHRONIZATION

    Directory of Open Access Journals (Sweden)

    N. Servetnyk

    2014-06-01

    Full Text Available The paper researches business cycles synchronization. The fluctuations in post-Soviet countries are considered. The study examines different measures of synchronization in groups of countries according to some criteria.

  10. The Black Studies Boondoggle

    Science.gov (United States)

    Long, Richard A.

    1970-01-01

    Indicates tendencies dangerous to the basic purpose of Black Studies, and identifies four external challeges--imperialism, paternalism, nihilism, and materialism. An internal challenge is considered to be the use of European and Establishment constructs to analyze black reality. (DM)

  11. Septic Systems Case Studies

    Science.gov (United States)

    A collection of septic systems case studies to help community planners, elected officials, health department staff, state officials, and interested citizens explore alternatives for managing their decentralized wastewater treatment systems.

  12. Mobile OS Comparative Study

    OpenAIRE

    Joseph, Jyothy; K, Shinto Kurian

    2013-01-01

    In the fast growing mobile revolutionary era, many operating systems are playing vital role in present market. This study is intending to identify the apt and secure mobile based on mobile operating systems capability and user requirements.

  13. Color transparency study group

    International Nuclear Information System (INIS)

    Appel, J.A.; Pordes, S.; Botts, J.; Bunce, G.; Farrar, G.

    1990-01-01

    The group studied the relatively new notion of color transparency, discussed present experimental evidence for the effect, and explored several ideas for future experiments. This write-up summarizes these discussions. 11 refs., 1 fig

  14. Earth study from space

    Science.gov (United States)

    Sidorenko, A. V.

    1981-01-01

    The significance that space studies are making to all Earth sciences in the areas of geography, geodesy, cartography, geology, meteorology, oceanology, agronomy, and ecology is discussed. It is predicted that cosmonautics will result in a revolution in science and technology.

  15. Tailored Barium Swallow Study

    Science.gov (United States)

    ... Impulse Oscillimetry (IOS) Hypoxic and Hypercapnic Drive Response Lung Diffusion Capacity Testing (DLCO) Maximum Inspiratory/Expiratory Pressures Nitrogen Washout Performing Pressure Volume Study Performing Routine Pulmonary Test Performing Spirometry Test ...

  16. Esophagram (Barium Swallow Study)

    Science.gov (United States)

    ... Impulse Oscillimetry (IOS) Hypoxic and Hypercapnic Drive Response Lung Diffusion Capacity Testing (DLCO) Maximum Inspiratory/Expiratory Pressures Nitrogen Washout Performing Pressure Volume Study Performing Routine Pulmonary Test Performing Spirometry Test ...

  17. Evidence: Study Guide. Revision

    National Research Council Canada - National Science Library

    1997-01-01

    ...) correct application of principles of military rules of evidence. This study guide is also intended to be a convenient reference for use by Navy and Marine Corps judge advocates and Coast Guard law...

  18. Reconnaissance Geochemical Study

    African Journals Online (AJOL)

    distribution patterns. The geochemical distribution maps of the elements reveal that Cu, Pb, Zn, Co, Sc, Ni, Cr, .... After filtration, the leached solutions were diluted with ultra ...... some other rare earth elements in the study area. The occurrence ...

  19. Study the Problem.

    Science.gov (United States)

    Choate, Joyce S.

    1990-01-01

    The initial step of a strategic process for solving mathematical problems, "studying the question," is discussed. A lesson plan for teaching students to identify and revise arithmetic problems is presented, involving directed instruction and supervised practice. (JDD)

  20. The Faroese IBD Study

    DEFF Research Database (Denmark)

    Hammer, Turid; Nielsen, Kari R.; Munkholm, Pia

    2016-01-01

    Background and Aims: Inflammatory bowel diseases [IBDs] include Crohn’s disease [CD], ulcerative colitis [UC], and IBD unclassified [IBDU]. In 2010 and 2011, the ECCO-EpiCom study found the worldwide highest incidence of inflammatory bowel disease [IBD] in the Faroe Islands: 83 per 100 000...... [European Standard Population, ESP]. The present study assessed the long-term time trends in IBD incidence in the Faroese population. Methods: In this population-based study, data were retrieved from the National Hospital of the Faroe Islands and included all incident cases of CD, UC, and IBDU diagnosed...... from 4 to 44, and for IBDU from 2 to 21 per 100 000 [ESP]. Conclusions: The high IBD incidence was found to be a relatively new phenomenon. The observed increase is unlikely to be an artefact resulting from, for instance, better registration. Our study indicated a real and increasing disease burden...

  1. South African Music Studies

    African Journals Online (AJOL)

    SAMUS: South African Music Studies is the official organ for the South African ... Shifty Records in Apartheid South Africa: Innovations in Independent Record ... Experiences of Belonging and Exclusion in the Production and Reception of ...

  2. Kuwait oil spill studied

    Science.gov (United States)

    Bush, Susan

    1992-02-01

    More than a year after the Persian Gulf War, scientists are still trying to assess the environmental impact of the estimated 6-8 million barrels of oil that were dumped into the gulf and to understand the environmental processes that take place in such a disturbance. Many atmospheric studies were done in the months immediately following the war, but oceanographic studies have been slower in getting started.The National Oceanic and Atmospheric Administration is currently spearheading a major oceanographic study being undertaken in the Persian Gulf by the research vessel Mt. Mitchell. The ship left its home port of Norfolk, Va., in mid-January and arrived in Muscat, Oman, on February 16 to begin a 100-day oceanographic and environmental survey. The six-leg cruise will feature physical oceanography, near-shore, and marine life studies.

  3. A qualitative study

    African Journals Online (AJOL)

    ismail - [2010

    Methods: A descriptive qualitative study was carried out in Adami Tulu District of East Shoa Zone – the ... to enhance teaching learning at CBE sites and facilitate ..... on good nutrition”. ... not observing any misbehavior: “The behavior of the.

  4. HYDROGEOLOGIC CASE STUDIES

    Science.gov (United States)

    Hydrogeology is the foundation of subsurface site characterization for evaluations of monitored natural attenuation (MNA). Three case studies are presented. Examples of the potentially detrimental effects of drilling additives on ground-water samples from monitoring wells are d...

  5. Digital signature feasibility study

    Science.gov (United States)

    2008-06-01

    The purpose of this study was to assess the advantages and disadvantages of using digital signatures to assist the Arizona Department of Transportation in conducting business. The Department is evaluating the potential of performing more electronic t...

  6. Accelerator research studies

    International Nuclear Information System (INIS)

    1992-01-01

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the first year of a three-year funding cycle. The program consists of the following three tasks: TASK A, Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams, TASK B, Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams; TASK C, Study of a Gyroklystron High-power Microwave Source for Linear Colliders. In this report we document the progress that has been made during the past year for each of the three tasks

  7. Study of biological compartments

    International Nuclear Information System (INIS)

    Rocha, A.F.G. da

    1976-01-01

    The several types of biological compartments are studied such as monocompartmental system, one-compartment balanced system irreversible fluxes, two closed compartment system, three compartment systems, catenary systems and mammilary systems [pt

  8. IRD dropout study

    Science.gov (United States)

    Yalowitz, Jeffrey S.; Schroer, Michael A.; Dickson, John E., Jr.

    1992-01-01

    This final report describes work performed by SRS Technologies for the NASA Marshall Space Flight Center under Contract NAS8-39077, entitled 'Integrated Receiver-Decoder Dropout Study'. The purpose of the study was to determine causes of signal fading effects on ultra-high-frequency (UHF) range safety transmissions to the Space Shuttle during flyout. Of particular interest were deep fades observed at the External Tank (ET) Integrated Receiver-Decoder (IRD) during the flyout interval between solid rocket booster separation and ET separation. Analytical and simulation methods were employed in this study to assess observations captured in flight telemetry data records. Conclusions based on the study are presented in this report, and recommendations are given for future experimental validation of the results.

  9. A Psychobiographical Case Study

    African Journals Online (AJOL)

    man, and cancer fighter. This psychobiographical case study entailed a psychosocial-historical ... does not draw more attention as a research method, as this approach has .... of the applied Levinsonian theory to the life of Jobs against the ...

  10. Applied Research Study

    Science.gov (United States)

    Leach, Ronald J.

    1997-01-01

    The purpose of this project was to study the feasibility of reusing major components of a software system that had been used to control the operations of a spacecraft launched in the 1980s. The study was done in the context of a ground data processing system that was to be rehosted from a large mainframe to an inexpensive workstation. The study concluded that a systematic approach using inexpensive tools could aid in the reengineering process by identifying a set of certified reusable components. The study also developed procedures for determining duplicate versions of software, which were created because of inadequate naming conventions. Such procedures reduced reengineering costs by approximately 19.4 percent.

  11. Thyroid function study

    International Nuclear Information System (INIS)

    Rocha, A.F.G. da

    1976-01-01

    A short revision of thyroid physiology is done. The radioisotopes of common use in thyroid investigation and the choice of the most appropriated ones are discussed. A table showing radioisotopes frequently used in this study, with their main characteristics is presented. Among several isotopic assays in thyroid propaedeutics, those that refer to the function study, topographic studies and tests 'in vitro' are pointed out. Exploration methods 'in vivo' are treated, such as: thyroid uptake; urinary excretion; thyroid scintigraphy, with scintigraphic imagings; stimulation test by TSH; suppression test; pbi; clearance test with perchlorate; iodine deficiency test and thyroid study with technetium. 'In vitro' proofs like triiodothyronine (T 3 ) and thyroxine (T 4 ) assays, as well as free thyroxine index, are treated. At last, the therapeutics by Iodine 131 is commented and emphasis is given to its application on the treatment of hyperthyroidism and thyroid carcinoma [pt

  12. PPB | Study Team

    Science.gov (United States)

    The Pleuropulmonary Blastoma (PPB) DICER1 Syndrome Study team is made up of researchers from the National Cancer Institute, Children¹s National Medical Center, the International Pleuropulmonary Blastoma Registry, and Washington University in St. Louis.

  13. 451 Case studies Cardiac

    African Journals Online (AJOL)

    Marinda

    Case Studies. 29 ... A case of a 26-year-old ASA I physical status male undergoing septoplasty had an abrupt ... myocardial infarction, severe hypertensive crisis, cerebral .... or no formal management is required in an ASA I patient.8 One.

  14. Chamberino Floodplain Management Study

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The Dona Ana County Flood Commission requested the United States Department of Agriculture's Natural Resources Conservation Service to conduct a study of the...

  15. Epidemiological studies on syncope

    DEFF Research Database (Denmark)

    Ruwald, Martin Huth

    2013-01-01

    of the patients play an essential role. In epidemiology these factors have major impact on the outcome of the patients. Until recently, even the definition of syncope differed from one study to another which has made literature reviews difficult. Traditionally the data on epidemiology of syncope has been taken...... from smaller studies from different clinical settings with wide differences in patient morbidity. Through the extensive Danish registries we examined the characteristics and prognosis of the patients hospitalized due to syncope in a nationwide study. The aims of the present thesis were to investigate......, prevalence and cardiovascular factors associated with the risk of syncope, 4) the prognosis in healthy individuals discharged after syncope, and 5) the prognosis of patients after syncope and evaluation of the CHADS2 score as a tool for short- and long-term risk prediction. The first studies of the present...

  16. Nature Study Tips. Spiders.

    Science.gov (United States)

    Mulaik, Stanley B.

    1990-01-01

    Different types of spiders, their ranges and habits are discussed. Activities associated with the study of spiders are suggested. Four references are listed which may be of interest to beginners. (CW)

  17. Advanced Propulsion Study

    National Research Council Canada - National Science Library

    Davis, Eric

    2004-01-01

    ... that show promise of leading to a major advance in Earth-to-orbit (ETO) propulsion. The study also reviewed and evaluated a select number of credible far-term breakthrough propulsion physics concepts pertaining...

  18. Public Key Infrastructure Study

    National Research Council Canada - National Science Library

    Berkovits, Shimshon

    1994-01-01

    The National Institute of Standards and Technology (NIST) has tasked The MITRE Corporation to study the alternatives for automated management of public keys and of the associated public key certificates for the Federal Government...

  19. African Studies Monographs

    African Journals Online (AJOL)

    The African Studies Monographs is a serial that promotes research and scholarship on the African perspective worldwide. This includes matters of philosophy, history, literature, arts and culture, environment, gender, politics, administration crisis management, etc.

  20. Thermoluminescence studies in geology

    International Nuclear Information System (INIS)

    Sankaran, A.V.; Sunta, C.M.; Nambi, K.S.V.; Bapat, V.N.

    1980-01-01

    Even though the phenomenon of thermoluminescence is well studied, particularly over last 3 decades, its potentialities in the field of geology have not been adequately evaluated. In this report several useful applications of TL in mineralogy, petrogenesis, stratigraphy, tectonics, ore-prospecting and other branches have been identified with particular emphasis to the Indian scene. Important areas in the country that may provide the basic material for such studies are indicated at the end along with brief geological or mineralogical accounts. (auth.)

  1. Qualitative Case Study Guidelines

    Science.gov (United States)

    2013-11-01

    Introduction to Sociological Methods. 2nd ed. New York, McGraw-Hill 14. Denzin , N. K. and Lincoln , Y. S. (2011) The SAGE Handbook of Qualitative...The Art of Science. In: Denzin , N. K. and Lincoln , Y. S. (eds.) Handbook of Qualitative Research. Thousand Oaks, Sage 19. GAO (1990) Case Study...Rinehart & Winston 39. Stake, R. E. (1994) Case Studies. In: Denzin , N. K. and Lincoln , Y. S. (eds.) Handbook of Qualitative Research. Thousand Oaks, Sage

  2. DOE's Yucca Mountain studies

    International Nuclear Information System (INIS)

    1992-12-01

    This booklet is about the disposal of high-level nuclear waste in the United States. It is for readers who have a general rather than a technical background. It discusses why scientists and engineers thinkhigh-level nuclear waste may be disposed of safely underground. It also describes why Yucca Mountain, Nevada, is being studied as a potential repository site and provides basic information about those studies

  3. University related studies

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Over the years, opportunities for terrestrial ecology studies have attracted student researchers associated with Pacific Northwest colleges and universities. During the past year, four students have been involved with undergraduate or graduate thesis projects. Brief descriptions of these studies are included in this section. It is expected that university participation will be enhanced by designating parts of the Hanford Reservation as a National Environmental Research Park (NERP)

  4. Workshop I: Gender Studies

    Science.gov (United States)

    Hennessey, Eden; Kurup, Anitha; Meza-Montes, Lilia; Shastri, Prajval; Ghose, Shohini

    2015-12-01

    Participants in the Gender Studies workshop of the 5th IUPAP International Conference on Women in Physics discussed the gender question in science practice from a policy perspective, informed by investigations from the social science disciplines. The workshop's three sessions—"Equity and Education: Examining Gender Stigma in Science," "A Comparative Study of Women Scientists and Engineers: Experiences in India and the US," and "Toward Gender Equity Through Policy: Characterizing the Social Impact of Interventions—are summarized, and the resulting recommendations presented.

  5. Vitrification melter study

    International Nuclear Information System (INIS)

    Jones, J.A.

    1995-04-01

    This report presents the results of a study performed to identify the most promising vitrification melter technologies that the Department of Energy (EM-50) might pursue with available funding. The primary focus was on plasma arc systems and graphite arc melters. The study was also intended to assist EM-50 in evaluating competing technologies, formulating effective technology strategy, developing focused technology development projects, and directing the work of contractors involved in vitrification melter development

  6. Tanzania country study

    Energy Technology Data Exchange (ETDEWEB)

    Meena, H E [Centre for Energy, Environment, Science and Technology, Dar es Salaam (Tanzania, United Republic of)

    1998-10-01

    An objective of this study is to analyse the role of the land use sectors of Tanzania (especially forestry) on mitigation of greenhouse gases. Specific emphasis is placed on the relationship between forestry and energy supply from biomass. This is a follow up study on an earlier effort which worked on mitigation options in the country without an in-depth analysis of the forestry and land use sectors. (au)

  7. Cerebral perfution studies

    International Nuclear Information System (INIS)

    Mut, Fernando

    1994-01-01

    For detecting in precocious form a coronary disease is necessary to aply a diagnostic techniques. The main considerations to be indicated in the present work are: physiological considerations, myocardial perfusion studies with radiotracers such as Talio 201, 99mTc, MIBI, 99mTc-Teboroxima, 99mTc-Fosfinas, instrumentation for obtain good images, proceedings protocols, studies interpretation, standards, SPECT, anomalies standards, coronary diseases

  8. Artificial Intelligence Study (AIS).

    Science.gov (United States)

    1987-02-01

    ARTIFICIAL INTELLIGNECE HARDWARE ....... 2-50 AI Architecture ................................... 2-49 AI Hardware ....................................... 2...ftf1 829 ARTIFICIAL INTELLIGENCE STUDY (RIS)(U) MAY CONCEPTS 1/3 A~NLYSIS AGENCY BETHESA RD R B NOJESKI FED 6? CM-RP-97-1 NCASIFIED /01/6 M |K 1.0...p/ - - ., e -- CAA- RP- 87-1 SAOFŔ)11 I ARTIFICIAL INTELLIGENCE STUDY (AIS) tNo DTICFEBRUARY 1987 LECT 00 I PREPARED BY RESEARCH AND ANALYSIS

  9. Radiation Studies, Vol.10

    International Nuclear Information System (INIS)

    Nadareishvili, K.; Tsitskishvili, M.; Chankseliani, Z.; Gelashvili, K.; Mtskhoetadze, A.; Oniani, T.; Todua, F.; Vepkhoadze, N.; Zaalishvili, T.

    2002-01-01

    'Radiation studies' - is a periodical edition of Scientific Research Center of Radiobiology and Radiation Ecology of Georgian Academy of Sciences, Problem Council of Radiobiology of Georgian Academy of Sciences and Georgian Academy of Ecological Sciences. The 10th volume of 'Radiation studies' reflects activities of above-mentioned institutions during previous two years and contains 26 articles, from which 17 are within the scope of INIS

  10. Evaluation of epidemiological studies

    International Nuclear Information System (INIS)

    Breckow, J.

    1995-01-01

    The publication is intended for readers with a professional background in radiation protection who are not experts in the field of epidemiology. The potentials and the limits of epidemiology are shown and concepts and terminology of radioepidemilogic studies as well as epidemiology in general are explained, in order to provide the necessary basis for understanding or performing evaluations of epidemiologic studies. (orig./VHE) [de

  11. Zambia country study

    Energy Technology Data Exchange (ETDEWEB)

    1999-09-01

    The Zambia Country Study, which was part of the Danida-funded project Climate Change Mitigation in Southern Africa: Phase 2, aimed at methodological development, national mitigation analysis and institutional capacity building in Zambia. The study comprised the following five elements: Comprehensive evaluation of national social and economic development framework for climate change; Baseline scenario(s) projection(s); Mitigation scenario(s) projection(s); Macro-economic assessment; Implementation Issues. (au) 17 refs.

  12. Tanzania country study

    International Nuclear Information System (INIS)

    Meena, H.E.

    1998-01-01

    An objective of this study is to analyse the role of the land use sectors of Tanzania (especially forestry) on mitigation of greenhouse gases. Specific emphasis is placed on the relationship between forestry and energy supply from biomass. This is a follow up study on an earlier effort which worked on mitigation options in the country without an in-depth analysis of the forestry and land use sectors. (au)

  13. Future ATLAS Higgs Studies

    CERN Document Server

    Smart, Ben; The ATLAS collaboration

    2017-01-01

    The High-Luminosity LHC will prove a challenging environment to work in, with for example $=200$ expected. It will however also provide great opportunities for advancing studies of the Higgs boson. The ATLAS detector will be upgraded, and Higgs prospects analyses have been performed to assess the reach of ATLAS Higgs studies in the HL-LHC era. These analyses are presented, as are Run-2 ATLAS di-Higgs analyses for comparison.

  14. clinical and experimental study

    OpenAIRE

    Tornow, Christoph

    2011-01-01

    Posterior capsule opacity (PCO) is a frequent complication in extracapsular cataract extraction in conjunction with an intraocular lens implant. Different studies have shown that a reduction in PCO frequency can be achieved via a number of factors. Lens design is a significant criterion in this process. In this study, two multifocal intraocular lenses (MIOLs) were compared. The design of these lenses differed due to their varying optical principles. They are the refractive MIOL A...

  15. Networked Microgrids Scoping Study

    Energy Technology Data Exchange (ETDEWEB)

    Backhaus, Scott N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dobriansky, Larisa [General MicroGrids, San Diego, CA (United States); Glover, Steve [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Liu, Chen-Ching [Washington State Univ., Pullman, WA (United States); Looney, Patrick [Brookhaven National Lab. (BNL), Upton, NY (United States); Mashayekh, Salman [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pratt, Annabelle [National Renewable Energy Lab. (NREL), Golden, CO (United States); Schneider, Kevin [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stadler, Michael [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Starke, Michael [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wang, Jianhui [Argonne National Lab. (ANL), Argonne, IL (United States); Yue, Meng [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-12-05

    Much like individual microgrids, the range of opportunities and potential architectures of networked microgrids is very diverse. The goals of this scoping study are to provide an early assessment of research and development needs by examining the benefits of, risks created by, and risks to networked microgrids. At this time there are very few, if any, examples of deployed microgrid networks. In addition, there are very few tools to simulate or otherwise analyze the behavior of networked microgrids. In this setting, it is very difficult to evaluate networked microgrids systematically or quantitatively. At this early stage, this study is relying on inputs, estimations, and literature reviews by subject matter experts who are engaged in individual microgrid research and development projects, i.e., the authors of this study The initial step of the study gathered input about the potential opportunities provided by networked microgrids from these subject matter experts. These opportunities were divided between the subject matter experts for further review. Part 2 of this study is comprised of these reviews. Part 1 of this study is a summary of the benefits and risks identified in the reviews in Part 2 and synthesis of the research needs required to enable networked microgrids.

  16. Study of wilms' tumor

    International Nuclear Information System (INIS)

    Khan, M.H.; Yaqub, N.

    2001-01-01

    This study is an effort to bring into light data related to children with Wilms' tumor managed at Islamabad as local literature on this topic is lacking. It was retrospective study. The study was conducted at Children Hospital, Pakistan Institute of Medical Science, Islamabad between January, 1987 and December 1995. All patients managed during the study period were included in the study. In all the patients complete blood count (CBC), urine analysis (D/R),X-ray abdomen and chest, ultrasound abdomen and in selected cases CT scan were performed. National Wilms' Tumor Study Group (NWTS 3) protocol was followed for further management. Fifty patients including 28 males and 22 females with the age range from 9 months to 8 years were managed in 9 years period. Left kidney was involved in 31 patients. Most of the tumors were solid on ultrasound, 76% patients were in stage III and IV. In one case bilateral involvement of kidney was found. Forty patients underwent primary surgery. Only 14 patients received complete course of chemotherapy while 31 radiotherapy. Nineteen patients died and 15 lost to follow-up. The survival and mortality rates are comparable to NWTS-3 results, although, most of the patients were presented in advance stage of Wilms tumor. The survival of these patients can be improved by increasing awareness of society through electronic and print media. (author)

  17. Studying Organizations on Instagram

    Directory of Open Access Journals (Sweden)

    Uta Russmann

    2016-10-01

    Full Text Available With the rise of social media platforms based on the sharing of pictures and videos, the question of how such platforms should be studied arises. Previous research on social media (content has mainly focused on text (written words and the rather text-based social media platforms Twitter and Facebook. Drawing on research in the fields of visual, political, and business communication, we introduce a methodological framework to study the fast-growing image-sharing service Instagram. This methodological framework was developed to study political parties’ Instagram accounts and tested by means of a study of Swedish political parties during the 2014 election campaign. In this article, we adapt the framework to also study other types of organizations active on Instagram by focusing on the following main questions: Do organizations only use Instagram to share one-way information, focusing on disseminating information and self-presentation? Or is Instagram used for two-way communication to establish and cultivate organization-public relationships? We introduce and discuss the coding of variables with respect to four clusters: the perception of the posting, image management, integration, and interactivity.

  18. Impact studies at Winfrith

    International Nuclear Information System (INIS)

    Cooper, C.A.; Wicks, S.J.

    1987-02-01

    Analytical and experimental studies of subsonic impacts on nuclear reactor plant structures have been in progress at Winfrith since 1977. These studies have examined the behaviour of concrete and metal structures under the impact of missiles typifying those derived either from the plant itself or from external sources, such as crashing aircraft. During 1986 the Winfrith programme was expanded to include studies of the behaviour of radioactive materials transport containers under impact conditions. This report initially describes the experimental facilities available for impact studies at Winfrith. These include both compressed air guns, capable of delivering payloads of up to 65 kg at sonic velocity or payloads up to 2 tonnes at speeds up to 45 ms -1 , and drop test facilities for impact testing of models, up to full-scale radioactive materials transport flasks, at relatively low speeds. Supporting facilities include a small concrete manufacturing laboratory to produce concrete targets. Assessments of the resistance of concrete or metal structures to impact damage are performed using empirical or semi-empirical correlations, derived from data obtained in well-characterised experiments, or using structural dynamics finite element codes. The codes used by the analysts and the computing facilities available for impact analysis work are described. Finally the current programme of impact studies is reviewed, recent progress is summarised and future plans outlined. (author)

  19. Cosmos-1989 immunology studies

    Science.gov (United States)

    Sonnenfeld, Gerald

    1991-01-01

    Evidence from both human and rodent studies has indicated that alterations in immunological parameters occur after space flight. The number of flight experiments has been small, and the full breadth of immunological alterations occurring after space flight remains to be established. Among the major effects on immune responses after space flight that have been reported are: alterations in lymphocyte blastogenesis and natural killer cell activity, alterations in production of cytokines, changes in leukocyte sub-population distribution, and decreases in the ability in the ability of bone marrow cells to respond to colony stimulating factors. Changes have been reported in immunological parameters of both humans and rodents. The significance of these alterations in relation to resistance to infection remains to be established. The current study involved a determination of the effects of flight on Cosmos mission 2044 on leukocyte subset distribution and the sensitivity of bone marrow cells to colony stimulating factor-GM. A parallel study with antiorthostatic suspension was also carried out. The study involved repetition and expansion of studies carried out on Cosmos 1887.

  20. Laboratory microfusion capability study

    International Nuclear Information System (INIS)

    1993-05-01

    The purpose of this study is to elucidate the issues involved in developing a Laboratory Microfusion Capability (LMC) which is the major objective of the Inertial Confinement Fusion (ICF) program within the purview of the Department of Energy's Defense Programs. The study was initiated to support a number of DOE management needs: to provide insight for the evolution of the ICF program; to afford guidance to the ICF laboratories in planning their research and development programs; to inform Congress and others of the details and implications of the LMC; to identify criteria for selection of a concept for the Laboratory Microfusion Facility and to develop a coordinated plan for the realization of an LMC. As originally proposed, the LMC study was divided into two phases. The first phase identifies the purpose and potential utility of the LMC, the regime of its performance parameters, driver independent design issues and requirements, its development goals and requirements, and associated technical, management, staffing, environmental, and other developmental and operational issues. The second phase addresses driver-dependent issues such as specific design, range of performance capabilities, and cost. The study includes four driver options; the neodymium-glass solid state laser, the krypton fluoride excimer gas laser, the light-ion accelerator, and the heavy-ion induction linear accelerator. The results of the Phase II study are described in the present report

  1. Indoor radon epidemiological study

    Energy Technology Data Exchange (ETDEWEB)

    Kunz, E; Tomasek, L; Mueller, T [National Radiation Protection Institute, Prague (Czech Republic); Placek, V [Inst. for Expertises and Emergencies, Pribram-Kamenna (Czech Republic); Matzner, J; Heribanova, A [State Office for Nuclear Safety, Prague (Czech Republic)

    1996-12-31

    The study is a long-term prospective cohort study of lung cancer and possibility other causes of death. The study population includes inhabitants of the area, who had resided there for at three years and at least one of these between 1.1.1960 and 21.12.1989. A total of 11865 inhabitants satisfied these criteria. The cumulative exposure of each respondent is being assessed on the basis of measurements in dwellings, time spent there and estimation of previous exposure levels by a model accounting for constructional changes in buildings. One year lasting measurements of radon daughter products by integral dosimeters (Kodak film LR 115) were performed in practically all dwellings of the specified area. Radon measurements in houses in term of equilibrium concentration are compared with the results of a pilot study in Petrovice in 1990-91 which gave the stimulus for the epidemiological study. The distribution of death causes and ratio of observed (O) to expected (E) cases among collected death cases in the cohort, generally, somewhat lower ratios than one reflect the non-industrial character of the region, with the exception of lung cancer in man. The differences in the O/E ratios for lung cancer among the separate communities indicate that even in the situation of generally lower mortality, the dependence of lung cancer mortality on radon.

  2. Photovoltaics information user study

    Energy Technology Data Exchange (ETDEWEB)

    Belew, W.W.; Wood, B.L.; Marie, T.L.; Reinhardt, C.L.

    1980-10-01

    The results of a series of telephone interviews with groups of users of information on photovoltaics (PV) are described. These results, part of a larger study on many different solar technologies, identify types of information each group needed and the best ways to get information to each group. The report is 1 of 10 discussing study results. The overall study provides baseline data about information needs in the solar community. It covers these technological areas: photovoltaics, passive solar heating and cooling, active solar heating and cooling, biomass energy, solar thermal electric power, solar industrial and agricultural process heat, wind energy, ocean energy, and advanced energy storage. An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from seven PV groups respondents are analyzed in this report: DOE-Funded Researchers, Non-DOE-Funded Researchers, Researchers Working for Manufacturers, Representatives of Other Manufacturers, Representatives of Utilities, Electric Power Engineers, and Educators.

  3. Environmental health studies

    International Nuclear Information System (INIS)

    Easterly, C.E.; Shank, K.E.

    1978-01-01

    The two major thrusts of the environmental health studies have been in the areas of health physics aspects of fusion power and methodology for assessing health effects related to nuclear facilities. Researchers were unable to discern a dose-response relationship or to find adverse health effects in the local population around nuclear facilities which might be related to radiation exposure. A second study analyzed the trends in incidence of cancer, congenital malformation, and fetal and infant mortality for Oak Ridge, Anderson County, and Roane County relative to Tennessee. Finally, a more in-depth study on congenital malformations and fetal mortality trends for nine East Tennessee counties surrounding Oak Ridge was completed. The objective of the Health Physics Aspects of Fusion Power Program is to provide, on a timely basis, scientific information and technical evaluations on the potential impacts of fusion power to occupational workers and to members of the public. The primary areas of study in this program during the past year have been (1) factors affecting calculations of dose resulting from a release of tritium, (2) an assessment of the potential for reducing occupational risk from exposures to tritium, and (3) experimental studies of tritium conversion from molecular hydrogen to tritiated water

  4. Functional studies using NMR

    International Nuclear Information System (INIS)

    McCready, V.R.; Leach, M.O.; Sutton; Ell, P.

    1986-01-01

    The object of this book is to discuss and evaluate an area of Nuclear Magnetic Resonance which to date has been less emphasized than it might be, namely the use of NMR for functional studies. The book commences with a discussion of the areas in which the NMR techniques might be needed due to deficiencies in other techniques. The physics of NMR especially relating to functional measurement are then explained. Technical factors in producing functional images are discussed and the use of paramagnetic substances for carrying out flow studies are detailed. Particular attention is paid to specific studies in the various organs. The book ends with a survey of imaging in each organ and the relation of NMR images to other techniques such as ultrasound, nuclear medicine and X-rays

  5. Florida statewide radiation study

    International Nuclear Information System (INIS)

    Nagda, N.L.; Koontz, M.D.; Fortmann, R.C.; Schoenborn, W.A.; Mehegan, L.L.

    1987-01-01

    Florida phosphate deposits contain higher levels of uranium than most other soils and rocks, thus exposing the population to higher-than-desirable levels of radon and its short-lived daughters. The Florida Legislature ordered a survey of significant land areas where an environmental radiation standard should be applied. Among other things, the study assessed indoor radon in 6,000 homes, soil radon at 3,000 residences, and all data existing prior to the study. The report explains the purpose of the study, how it was designed and conducted, and its results. It concludes with a discussion of radon/radon decay product equilibrium factor, correlation between indoor and soil radon, and preliminary attempts to develop a safe threshold for soil radon below which few elevated indoor levels would be anticipated

  6. Oxidizer Scoping Studies

    Energy Technology Data Exchange (ETDEWEB)

    Chancellor, Christopher John [Los Alamos National Laboratory

    2016-11-07

    The purpose of this report is to present the results of the acceptable knowledge (AK) review of oxidizers present in active waste streams, provide a technical analysis of the oxidizers, and report the results of the scoping study testing. This report will determine the fastest burning oxidizer to be used in the development of a Test Plan for Preparation and Testing of Sorbents Mixed with Oxidizer found in Transuranic Waste (DWT-TP-001). The companion report, DWT-RPT-002, Sorbent Scoping Studies, contains similar information for sorbents identified during the AK review of TRU waste streams. The results of the oxidizer and sorbent scoping studies will be used to inform the QL1 test plan. The QL1 test results will support the development of a basis of knowledge document that will evaluate oxidizing chemicals and sorbents in TRU waste and provide guidance for treatment.

  7. Seal design alternatives study

    International Nuclear Information System (INIS)

    Van Sambeek, L.L.; Luo, D.D.; Lin, M.S.; Ostrowski, W.; Oyenuga, D.

    1993-06-01

    This report presents the results from a study of various sealing alternatives for the WIPP sealing system. Overall, the sealing system has the purpose of reducing to the extent possible the potential for fluids (either gas or liquid) from entering or leaving the repository. The sealing system is divided into three subsystems: drift and panel seals within the repository horizon, shaft seals in each of the four shafts, and borehole seals. Alternatives to the baseline configuration for the WIPP seal system design included evaluating different geometries and schedules for seal component installations and the use of different materials for seal components. Order-of-magnitude costs for the various alternatives were prepared as part of the study. Firm recommendations are not presented, but the advantages and disadvantages of the alternatives are discussed. Technical information deficiencies are identified and studies are outlined which can provide required information

  8. Parylene C Aging Studies.

    Energy Technology Data Exchange (ETDEWEB)

    Achyuthan, Komandoor; Sawyer, Patricia Sue.; Mata, Guillermo Adrian; White II, Gregory Von; Bernstein, Robert

    2014-09-01

    Parylene C is used in a device because of its conformable deposition and other advantages. Techniques to study Parylene C aging were developed, and "lessons learned" that could be utilized for future studies are the result of this initial study. Differential Scanning Calorimetry yielded temperature ranges for Parylene C aging as well as post-deposition treatment. Post-deposition techniques are suggested to improve Parylene C performance. Sample preparation was critical to aging regimen. Short-term (%7E40 days) aging experiments with free standing and ceramic-supported Parylene C films highlighted "lessons learned" which stressed further investigations in order to refine sample preparation (film thickness, single sided uniform coating, machine versus laser cutting, annealing time, temperature) and testing issues ("necking") for robust accelerated aging of Parylene C.

  9. The Hi Five study

    DEFF Research Database (Denmark)

    Johansen, Anette; Denbæk, Anne Maj; Bonnesen, Camilla Thørring

    2015-01-01

    of school toilets during the school day. Baseline data was collected from December 2011 to April 2012. The intervention period was August 2012 to June 2013. The follow-up data was collected from December 2012 to April 2013. DISCUSSION: The Hi Five study fills a gap in international research. This large......BACKGROUND: Infectious illnesses such as influenza and diarrhea are leading causes of absenteeism among Danish school children. Interventions in school settings addressing hand hygiene have shown to reduce the number of infectious illnesses. However, most of these studies include small populations...... and almost none of them are conducted as randomized controlled trials. The overall aim of the Hi Five study was to develop, implement and evaluate a multi-component school-based intervention to improve hand hygiene and well-being and to reduce the prevalence of infections among school children...

  10. Underground layout tradeoff study

    International Nuclear Information System (INIS)

    1988-01-01

    This report presents the results of a technical and economic comparative study of four alternative underground layouts for a nuclear waste geologic repository in salt. The four alternatives considered in this study are (1) separate areas for spent fuel (SF) and commercial high-level waste (CHLW); (2) panel alternation, in which SF and CHLW are emplaced in adjacent panels of rooms; (3) room alternation, in which SF and CHLW are emplaced in adjacent rooms within each panel; and (4) intimate mixture, in which SF and CHLW are emplaced in random order within each storage room. The study concludes that (1) cost is not an important factor; (2) the separate-areas and intimate-mixture alternatives appear, technically, to be more desirable than the other alternatives; and (3) the selection between the separate-areas and intimate mixture alternatives depends upon future resolution of site-specific and reprocessing questions. 5 refs., 6 figs., 12 tabs

  11. Waarom Jesus-studies?

    Directory of Open Access Journals (Sweden)

    P. A. Geyser

    2000-12-01

    Full Text Available Why Jesus studies? Present-day historical Jesus studies are the epistemological product of what has become known as the New Historicism. The aim of the article is to emphasize two aspects of the New Historicism as epistemological approach. The one aspect focuses on the profitability of this endeavour and the other on the historical nature of the New Historicism. As far as profitability is concerned, the social standing and identity of the researcher are emphasized. Among otherthings, the social interests of the researcher are taken into account. Concerning the historical nature of this kind of research, a distinction is drawn between the Jesus of history and the Jesus of faith. The aim of the article is to gain clarity on the relationship between the Jesus of history (pre-Easter and the Jesus of faith (post-Easter. J D Crossan's exposition of the reasons for Jesus studies is followed. He distinguishes three reasons: historical, ethical and theological.

  12. Operation and machine studies

    International Nuclear Information System (INIS)

    1992-01-01

    This annual report describes the GANIL (Grand accelerateur national d'ions lourds, Caen, France) operation and the machine studies realized in 1992. Metallic ions have been accelerated during 36 pc of the time; some were produced for the first time at GANIL: 125 Te, 52 Cr with ECR3, 181 Ta with ECR4. The various machine studies are: comparison of lifetimes of carbon sheets, charge exchange of very heavy ions in carbon foils and in the residual gas of the Ganil cyclotrons, commissioning of the new high intensity axial injection system for Ganil, tantalum acceleration with the new injector, a cyclotron as a mass spectrometer; other studies concerned: implementing the new control system, gettering flux measurement, energy deposited by neutrons and gamma rays in the cryogenic system of SISSI; latest developments on multicharged ECR ion sources, and an on-line isotopic separator test bench at Ganil

  13. STUDY ON VIRTUAL COLONOSCOPY

    Directory of Open Access Journals (Sweden)

    Aithagani Rama Chandraiah

    2016-10-01

    Full Text Available BACKGROUND Current options available in the investigations of colorectal carcinoma include screening using digital rectal examination, sigmoidoscopy, barium enema and fiberoptic colonoscopy, virtual colonoscopy. The aim of the study was to prospectively evaluate patient acceptance of virtual colonoscopy compared with that of conventional colonoscopy when performed in patients with or suspected of having colorectal disease. MATERIALS AND METHODS The study had been conducted on patients attending Department of Radiology for a period of 1 year. Patients with primary or secondary complaints of pain abdomen, lump in abdomen, bleeding per rectum, loose motions/constipation, altered bowel habits, loss of appetite and weight and anaemia, so total number of cases were 51. RESULTS In our study, the patients were in age groups of 21-70 years. Both sexes were represented in our study. Male preponderance was noted in 51 patients. Cases of adenoma were more commonly found 37 (72.78%. The sensitivity of the CT colonography for the polyps more than 10 mm is 100%, polyps 6-9 mm is 90%, less than 6 mm is 80%. Our study consists of 51 patients; among them, 30 patients showed acceptance for CT colonography, 10 patients for optical colonoscopy. Our study consists of 51 patients, the polyps (more than 10 mm detected in 2D viewing were 24, 2D and 3D viewing of 24, the polyps (less than 10 mm detected in 2D viewing were 15, 2D and 3D viewing were 17. 3D viewing resulted in increased sensitivity for identification of patients with larger polyps more than 1 cm, (70-85% sensitivity and patients with smaller polyps less than 1 cm (increased sensitivity 75-88%. CONCLUSIONS Multislice CT (64 colonography is a good alternative to other colorectal screening tests because it has high sensitivity for polyps 10 mm or more in diameter is relatively safe, clinical effective, minimally invasive, cost effective and filter for therapeutic optical colonoscopy.

  14. Making Media Studies

    Directory of Open Access Journals (Sweden)

    David Gauntlett

    2015-12-01

    Full Text Available This podcast is a recording of a research seminar that took place on December 3, 2015, at the University of Westminster's Communication and Media Research Institute (CAMRI. In this contribution, David Gauntlett discusses his new book, Making Media Studies, and other new work. In Making Media Studies (Peter Lang, 2015, Gauntlett proposes a vision of media studies based around doing and making – not about the acquisition of skills, as such, but an experience of building knowledge and understanding through creative hands-on engagement with all kinds of media. Gauntlett suggests that media studies scholars have failed to recognise the significance of everyday creativity – the vital drive of people to make, exchange, and learn together, supported by online networks. He argues that we should think about media in terms of conversations, inspirations, and making things happen. Media studies can be about genuine social change, he suggests, if we recognise the significance of everyday creativity, work to transform our tools, and learn to use them wisely. David Gauntlett is a Professor in the School of Media, Arts and Design at the University of Westminster, where he is also the School's Co-Director of Research. He is the author of several books, including: Creative Explorations (2007, Media, Gender and Identity: An Introduction (2nd edition 2008, Making is Connecting (2011, and Making Media Studies (2015. He has made a number of popular online resources, videos and playthings, and has pioneered creative research and workshop methods. He is external examiner for Information Experience Design at the Royal College of Art, London.

  15. Application Actuation Trade Study

    Science.gov (United States)

    1982-01-01

    32 RCA PRICE-L Podel Calculated 0 & S Values 138 33 RCA PRICE LCC Summery - Typical LRU 139 34 Airplane Actuation Trade Study LCC Summary 140 35...results achieved can be duplicated by a user. The RCA PRICE Podel calculates the RDTSE. Production cost, and creates the YiDF file for use in the PCA...PR ICE L). Some of the basic program ground rules for this study were as follows: RCA - PRICE Cost Podel RCA - PRICE L Model Prototype Hardware 10

  16. Study of estuarine dynamics

    International Nuclear Information System (INIS)

    Genders, S.

    1979-01-01

    A case study of a shallow, well mixed fjord illustrates the use of radioactive and an activable tracer. An instantaneous injection of the rare earth lanthanum was used as an activable tracer to determine residence-time and internal recirculation in the fjord system. An instantaneous injection of bromine-82 was used to investigate tae bypass of water from a harbour area through a power plant cooling water system to a partly enclosed basin of the fjord. Instantaneous releases of bromine-82 were further used for short time studies of the primary spread and transport of river water discharged to the inner section of the fjord system. (Author) [pt

  17. Regional Studies Program

    International Nuclear Information System (INIS)

    Parzyck, D.C.

    1978-01-01

    Progress is reported on methodology studies with regard to hydrologic analysis; atmospheric transport; forest growth models; distribution of sensitive species; agricultural analysis; and environmental objectives in energy facility siting. National coal utilization assessment studies are reported with regard to technology characterization; air quality impacts; water resources; regional characterization; forest impacts; coal extraction impacts on sensitive animal species; and health impacts. The following special projects were carried out: water resource aspects of inexhaustible technology deployment; ecological constraints on the rapidly expanded use of coal; and U.S. coal and the global carbon problem

  18. Studies in Rheoencephalography (REG

    Directory of Open Access Journals (Sweden)

    Michael Bodo

    2010-01-01

    Full Text Available This article presents an overview of rheoencephalography (REG – electrical impedance measurements of the brain – and summarizes past and ongoing research to develop medical applications of REG for neuro-critical care and for primary prevention of stroke and cardiovascular disease. The availability of advanced electronics and computation has opened up the potential for use of REG technology as a noninvasive, continuous and inexpensive brain monitor for military and civilian applications. The clinical background information presented here introduces physiological and clinical environments where REG has potential for use in research and clinical settings. REG studies over the past three decades have involved in vitro and in vivo groups (animal and human, including more than 1500 measurements and related electronic and computational results and practical applications. In vitro studies helped researchers understand the flow/volume relationship between Doppler ultrasound and electrical impedance signals and supported development of REG data processing methods. In animal studies, REG was used to monitor the lower limit of cerebral blood flow (CBF autoregulation (AR using a newly developed algorithm. These animal studies also confirmed correlations between REG and measurements of carotid flow (CF and intracranial pressure (ICP. Human studies confirmed the applicability of REG for detecting cerebrovascular alteration, demonstrating the usefulness of REG in the field of stroke/cardio-vascular disease prevention. In these studies, REG was compared to known stroke risk factors and to results obtained using carotid ultrasound measurements. An intelligent REG system (Cerberus has been developed for primary stroke prevention. In these studies, the biologically relevant variables of the REG signal were pulse amplitude (minimum – maximum distance and duration of the anacrotic (rising portion of the REG pulse wave. The principal limitation of REG for

  19. Reporting of teratology studies.

    Science.gov (United States)

    Barrow, Paul C; Reynaud, Lucie

    2013-01-01

    The regulatory toxicology report is an unusual document that requires a particular skill to write. The report must be clear, accurate, concise, and focused. A clear and direct writing style is required. The end-users of the report will hope to find the information they seek with as little effort as possible. Few, or none, will read the entire document. The author should aim to appease the user by obliging him to read as little text and turn as few pages as possible. This chapter gives tips and guidance on how to present the experimental data and write the narrative text in the final study report for a teratology study.

  20. Biological study in schizophrenia

    International Nuclear Information System (INIS)

    Kasai, Kiyoto; Yoshikawa, Akane; Natsubori, Takanobu; Koike, Shinsuke; Nagai, Tatsuya; Araki, Tsuyoshi; Nishimura, Yukika; Iwamoto, Kazuya

    2012-01-01

    Schizophrenia is associated with enormous morbidity, mortality, personal disability, and social cost. Although considerable research on schizophrenia has been performed, the etiology of this disease has not been fully elucidated. In recent years, imaging and genetic technologies have been developed dramatically. Disturbances in glutamate and gamma-aminobutyric acid (GABA)ergic neurotransmission may underlie the pathophysiology of schizophrenia. We attempted an integrative review, of studies pertaining to recent advances of schizophrenia research with a focus on neuroimaging and genetic studies. Additionally, we present the preliminary findings of the clinical research in our outpatient unit, specialized for early intervention, at the University of Tokyo Hospital. (author)

  1. CTR plasma engineering studies

    International Nuclear Information System (INIS)

    Miley, G.H.

    1990-01-01

    The main focus of the work by the Fusion Plasma Engineering Group at the University during the prior contract year involved a study of fusion ash (helium) effects on burn efficiency and on potential ways to control ash buildup. This work has wide application to a variety of fusion reactor concepts, but the immediate application for the present work is in the ARIES tokamak reactor design study now being undertaken by a national design team headed by the UCLA. The examples presented here largely deal with the ARIES-I design which is a D-T device operating in the first instability regime

  2. Throughput rate study

    International Nuclear Information System (INIS)

    Ford, L.; Bailey, W.; Gottlieb, P.; Emami, F.; Fleming, M.; Robertson, D.

    1993-01-01

    The Civilian Radioactive Waste Management System (CRWMS) Management and Operating (M ampersand O) Contractor, has completed a study to analyze system wide impacts of operating the CRWMS at varying throughput rates, including the 3000 MTU/year rate which has been assumed in the past. Impacts of throughput rate on all phases of the CRWMS operations (acceptance, transportation, storage and disposal) were evaluated. The results of the study indicate that a range from 3000 to 5000 MTU/year is preferred, based on system cost per MTU of SNF emplaced and logistics constraints

  3. Methodology of site studies

    International Nuclear Information System (INIS)

    Caries, J.C.; Hugon, J.; Grauby, A.

    1980-01-01

    This methodology consists in an essentially dynamic, estimated and follow-up analysis of the impact of discharges on all the environment compartments, whether natural or not, that play a part in the protection of man and his environment. It applies at two levels, to wit: the choice of site, or the detailed study of the site selected. Two examples of its application will be developed, namely: at the choice of site level in the case of marine sites, and of the detailed study level of the chosen site in that of a riverside site [fr

  4. ARIES tokamak reactor study

    International Nuclear Information System (INIS)

    Steiner, D.; Embrechts, M.

    1990-07-01

    This is a status report on technical progress relative to the tasks identified for the fifth year of Grant No. FG02-85-ER52118. The ARIES tokamak reactor study is a multi-institutional effort to develop several visions of the tokamak as an attractive fusion reactor with enhanced economic, safety, and environmental features. The ARIES study is being coordinated by UCLA and involves a number of institutions, including RPI. The RPI group has been pursuing the following areas of research in the context of the ARIES-I design effort: MHD equilibrium and stability analyses; plasma-edge modeling and blanket materials issues. Progress in these areas is summarized herein

  5. Camp Marmal Flood Study

    Science.gov (United States)

    2012-03-01

    was simulated by means of a broad - crested weir built into the topography of the mesh. There is 0.5 m of freeboard and the width of the weir is 30 m...ER D C/ CH L TR -1 2- 5 Camp Marmal Flood Study Co as ta l a nd H yd ra ul ic s La bo ra to ry Jeremy A. Sharp , Steve H. Scott...Camp Marmal Flood Study Jeremy A. Sharp , Steve H. Scott, Mark R. Jourdan, and Gaurav Savant Coastal and Hydraulics Laboratory U.S. Army Engineer

  6. Alecto 2 - interaction studies

    International Nuclear Information System (INIS)

    Brunet, J.P.; Clouet d'Orval, Ch.; Mougniot, J.C.; Penet, F.

    1965-01-01

    Weak interactions were experimentally studies with the tank of the critical assembly Alecto II and one, two or three bottles containing solutions of various concentrations. In particular, was studied the validity of certain classical assumptions, shielding effects, screening and semi-reflexion effects, importance of thermal coupling. The method of the 'k eff , solid angle' is shown to apply to such a system. The determination by divergence and pulsed neutron technique of the reactivity related to a millimeter of solution level affords the obtention of critical heights in terms of reactivity. (authors) [fr

  7. Rockwell support studies

    International Nuclear Information System (INIS)

    Rogers, L.E.

    1978-01-01

    The Rockwell Hanford Operations (RHO) supported ecological studies are designed to clarify ecosystem structure and functioning as pertaining to the management of radioactive waste control areas. To date, emphasis has been placed on characterizing the abiotic and biotic components of these areas, resulting in publication of over 20 PNL documents and several scientific articles pertinent to the 200 Area Waste Management Program. Results are reported from studies on the food habits of ground-dwelling beetles, mule deer, and American Coots inhabiting the areas, and the radiation dose received by rodents inhabiting waste management areas

  8. CCNA Wireless Study Guide

    CERN Document Server

    Lammle, Todd

    2010-01-01

    A complete guide to the CCNA Wireless exam by leading networking authority Todd Lammle. The CCNA Wireless certification is the most respected entry-level certification in this rapidly growing field. Todd Lammle is the undisputed authority on networking, and this book focuses exclusively on the skills covered in this Cisco certification exam. The CCNA Wireless Study Guide joins the popular Sybex study guide family and helps network administrators advance their careers with a highly desirable certification.: The CCNA Wireless certification is the most respected entry-level wireless certification

  9. A longitudinal study

    OpenAIRE

    Kristen, Astrid

    2010-01-01

    Does playing violent video games increase aggressive behavior over time or is it aggressive children who increasingly seek out (and play) these violent video games? To study such long-term effects a longitudinal design is necessary. Within a field study in a large German city (Kinder, Computer, Hobby, Lernen – KUHL, Freie Universtität Berlin) about 115 elementary school boys attending in the beginning (t1) classrooms of the third and fourth grade and twelve months later (t2) classrooms of the...

  10. Study of genital lesions

    Directory of Open Access Journals (Sweden)

    Anand Kumar B

    2003-03-01

    Full Text Available A total of one hundred patients (75 males and 25 females age ranged from 17-65 years with genital lesions attending the STD clinic of Bowring and LC Hospitals Bangalore constituted the study group. Based on clinical features, the study groups were classified as syphilis (39, chancroid (30, herpes genitolis (13, condylomato lato (9, LGV (7t condylomata acuminata (5, genital scabies (3, granuloma inguinole (2 and genital candidiasis (1. In 68% microbiological findings confirmed the clinical diagnosis. Of the 100 cases 13% and 2% were positive for HIV antibodies and HbsAg respectively.

  11. Morphing Terminology Study

    Energy Technology Data Exchange (ETDEWEB)

    Rose, Stuart J.; Brockman, Fred J.; Hart, Michelle L.; Engel, David W.; Valentine, Nancy B.; Calapristi, Augustin J.

    2010-06-28

    This study investigates methods of automatically identifying and characterizing significant transitions in term usage over time. Within scientific literature, the occurrence of terms reflects the use of technologies and techniques as well as the study of specific species and materials. Transitions in terminology usage may be a result of vocabulary standardization or specialization in which terms are replaced with their shorter form. They may also be a result of new applications, combinations, alternatives, or interests that result in the appearance of new or existing terminology in unexpected contexts.

  12. Case study - Argentina

    International Nuclear Information System (INIS)

    Diaz, E.

    1986-01-01

    Antecedents and experience of nuclear activities in Argentina; the Atomic Energy Commission (CNEA). First development and research activities. Research reactors and radioisotopes plants. Health physics and safety regulations. - Feasibility studies for the first nuclear power plant. Awarding the first plant CNA I (Atucha I). Relevant data related to the different project stages. Plant performance. - Feasibility study for the second nuclear power plant. Awarding the second plant CNE (Central Nuclear Embalse). Relevant data related to established targets. Differences compared with the first station targets. Local participation. Plant performance. (orig./GL)

  13. Critical cyberculture studies

    CERN Document Server

    Silver, David; Jones, Steve

    2006-01-01

    Starting in the early 1990s, journalists and scholars began responding to and trying to take account of new technologies and their impact on our lives. By the end of the decade, the full-fledged study of cyberculture had arrived. Today, there exists a large body of critical work on the subject, with cutting-edge studies probing beyond the mere existence of virtual communities and online identities to examine the social, cultural, and economic relationships that take place online. Taking stock of the exciting work that is being done and positing what cyberculture's future might look like, Criti

  14. Solid State Studies Section

    Energy Technology Data Exchange (ETDEWEB)

    None

    1974-12-31

    Research is summarized on fuel, fertile, and cladding materials. Results of studies in the field of solid state sciences are also reported. It was found during the studies on the thermal diffusion release of /sup 133/Xe from irradiated thoria--urania powders that during prolonged annealing at high temperatures, there were several sudden burst releases of /sup 133/Xe as a function of time. These sudden bursts appear to be related to the particle size of the powders. Studies on the phase composition of U/sub 3/O/sub 8//su established that the phase obtained at room temperature after heating at 850 deg K is always oxygen deficient. Results of studies on the different modifications of U/sub 3/O/sub 8/ indicated that the so-called delta-phase has a crystal structure almost identical with the beta-phase, yet there were differences in the heats of transition of each of these phases to the alpha-U/sub 3/O/sub 8/ phase at 130 deg C. Studies on fast neutron damage in stainless steel were initiated and results related to damage by void formation were obtained even when the fluencies were only moderately high. Studies on the phase transformations in solids brought out the unusual phase transition behavior of KNO/sub 3/. It was established that the phase transformation attributed to the orthorhombic (II) to the trigonal (I) transition at 129 deg C is essentially a 2-step transition. Results of differential scanning colorimeter (DSC) studies also revealed a peculiar feature which is as yet not understood, namely that on cooling, differential thermal analysis (DTA) showed a III to II phase transition; this is not seen in the DSC. The capabilities of the DSC technique to delineate temperatures of magnetic transitions were demonstrated by studying the transitions in a number of standard substances (metals, alloys, and compounds). In studies on KMnF/sub 3/, it was further demonstrated that the DSC technique is superior in measuring and detecting the heats of crystallographic and

  15. Case Studies - Cervical Cancer

    Centers for Disease Control (CDC) Podcasts

    Dr. Alan Waxman, a professor of obstetrics and gynecology at the University of New Mexico and chair of the American College of Obstetricians and Gynecologists (ACOG) committee for the underserved, talks about several case studies for cervical cancer screening and management.

  16. Studies on continuous fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, K

    1958-01-01

    Continuous fermentation of molasses with a combined system of agitated vessel and flow pipe is studied. A new apparatus was designed. The rate of the fermentation was faster with this apparatus than with the former apparatus which was composed of two vessels.

  17. Electron beam diagnostics study

    International Nuclear Information System (INIS)

    Garganne, P.

    1989-08-01

    This paper summarizes the results of a study on beam diagnostics, using carbon wire scanners and optical transition radiation (DTR) monitors. The main consideration consists in the material selection, taking their thermal properties and their effect on the beam into account [fr

  18. Positron imaging studies

    International Nuclear Information System (INIS)

    Budinger, T.F.; Ganz, E.; Moyer, B.R.; Yano, Y.; Mathis, C.A.; Friedland, R.P.

    1982-01-01

    Several methods for the noninvasive evaluation of the metabolism and blood perfusion of brain and heart are reviewed. Heart muscle perfusion can be followed by measuring the accumulation of rubidium-82 simultaneously with the measurement of the arterial input. Deoxyglucose labelled with fluorine-18 was used to study the role of insulin in deoxyglucose accumulation

  19. Nuclear forensics case studies

    International Nuclear Information System (INIS)

    Fedchenko, Vitaly

    2016-01-01

    The objective of this presentation is to share three case studies from the Institute of Transuranium Elements (ITU) which describe the application of nuclear forensics to events where nuclear and other radioactive material was found to be out of regulatory control

  20. Studies in Chemical Dynamics

    International Nuclear Information System (INIS)

    Rabitz, Herschel; Ho, Tak-San

    2003-01-01

    This final report draws together the research carried from February, 1986 through January, 2003 concerning a series of topics in chemical dynamics. The specific areas of study include molecular collisions, chemical kinetics, data inversion to extract potential energy surfaces, and model reduction of complex kinetic systems

  1. Polysomnography (Sleep Study)

    Science.gov (United States)

    ... this stage, your brain waves, as recorded by electroencephalography (EEG), slow down considerably. Your eyes don't move ... necessary, oxygen also may be used during the study to bolster your ... for PAP or oxygen in case your doctor would like to prescribe these for ...

  2. Post commissioning noise study

    International Nuclear Information System (INIS)

    Heraud, P.

    2008-01-01

    This presentation described a wind farm post-commissioning study conducted at a wind farm owned by Helimax Energy Inc. The farm was located in a partly-forested, partly cultivated region in Quebec that featured gently rolling hills. Over 600 dwellings were located within 2 km of the wind farm, and 44 dwellings were within the wind farm's boundaries. The noise impact assessments were conducted at various points near the wind farm. The wind farm was designed using an International Standards Organization (ISO) noise propagation model and a 40 dBA to provide adequate setbacks. The study was conducted using 10 days of continuous measurements at selected points of a wind farm. Points of reception included points from 650 m to 800 m. Noise over 2 km was not thought to be contributed by the wind turbine. The nearest dwelling was 512 m from one of the farm's wind turbines. The study also considered ground factor, temperature, relative humidity, and the height of the receptors. Quebec noise level limits are 40 dBA at night, and 45 dBA during the day. Noise level limits are independent of wind speed. Measured noise contributions over 40 dBA were not observed during the measurement program. The wind turbines were only audible for 1 night out of the 30 night study period. It was concluded that the ISO noise propagation model is a reliable tool for conducting noise impact assessments. tabs., figs

  3. Acid Rain Study Guide.

    Science.gov (United States)

    Hunger, Carolyn; And Others

    Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…

  4. Fusion energy studies

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    The following topics are considered: (1) cryosorption vacuum pumping for fusion reactors, (2) TNS support studies, (3) tritium recovery from irradiated Li-Al and SAP, (4) actinide oxides, nitrides, and carbides, and (5) transition metal-actinide-C phase equilibria

  5. Eastern Frequency Response Study

    Energy Technology Data Exchange (ETDEWEB)

    Miller, N.W.; Shao, M.; Pajic, S.; D' Aquila, R.

    2013-05-01

    This study was specifically designed to investigate the frequency response of the Eastern Interconnection that results from large loss-of-generation events of the type targeted by the North American Electric Reliability Corp. Standard BAL-003 Frequency Response and Frequency Bias Setting (NERC 2012a), under possible future system conditions with high levels of wind generation.

  6. Solid waste study

    International Nuclear Information System (INIS)

    Ortiz, Paul G.

    1995-01-01

    The purpose of this document is to study the solid waste issues brought about by a Type C Investigation; ''Disposal of Inappropriate Material in the Los Alamos County Landfill'' (May 28, 1993). The study was completed in August 1995 by Coleman Research Corporation, under subcontract number 405810005-Y for Los Alamos National Laboratory (LANL). The study confirmed the issues identified in the Type C investigation, and also ascertained further issues or problems. During the course of this study two incidents involving hazardous waste resulted in the inappropriate disposal of the waste. An accidental spill, on June 8, 1995, at one of Laboratory buildings was not handled correctly, and ended up in the LAC Landfill. Hazardous waste was disposed of in a solid waste container and sent to the Los Alamos County Landfill. An attempt to locate the hazardous waste at the LAC Landfill was not successful. The second incident involving hazardous waste was discovered by the FSS-8, during a random dumpster surveillance. An interim dumpster program managed by FSS-8 discovered hazardous waste and copper chips in the solid waste, on August 9, 1995. The hazardous waste and copper chips would have been transported to the LAC Landfill if the audit team had not brought the problem to the awareness of the facility waste management personnel

  7. Punta Higuero environmental studies

    International Nuclear Information System (INIS)

    Wood, E.D.; Youngbluth, M.J.; Nutt, M.E.; Yeaman, M.N.; Yoshioka, P.; Canoy, M.J.

    1975-01-01

    Site selection surveys and environmental research studies of seven coastal sites in Puerto Rico for construction of power generating facilities were carried out. Data are presented on the physical, chemical, and geological parameters of the Punta Higuero site, and the ecological parameters of zooplankton, benthic invertebrates, and fish communities. Plant associations are included. (U.S.)

  8. [Internal migration studies].

    Science.gov (United States)

    Stpiczynski, T

    1986-10-01

    Recent research on internal migration in Poland is reviewed. The basic sources of data, consisting of censuses or surveys, are first described. The author discusses the relationship between migration studies and other sectors of the national economy, and particularly the relationship between migration and income.

  9. Studies of Giardia lamblia

    Science.gov (United States)

    1994-10-05

    isoenzyme analysis of 19 axenic strains isolated from symptomatic and asymptomatic patients in Mexico . Trans. R. Soc. Trop. Med. Hyg. 83 : 644-646...antibody studies with agents of Varicella and Herpes Zoster propagated in vitro. Proe. Soc. Exptl. BioI. Med . 86 :7 89-794. Woo, P. and G.S. Panayi

  10. Nippon Storm Study design

    Directory of Open Access Journals (Sweden)

    Takashi Kurita

    2012-10-01

    Full Text Available An understanding of the clinical aspects of electrical storm (E-storms in patients with implantable cardiac shock devices (ICSDs: ICDs or cardiac resynchronization therapy with defibrillator [CRT-D] may provide important information for clinical management of patients with ICSDs. The Nippon Storm Study was organized by the Japanese Heart Rhythm Society (JHRS and Japanese Society of Electrocardiology and was designed to prospectively collect a variety of data from patients with ICSDs, with a focus on the incidence of E-storms and clinical conditions for the occurrence of an E-storm. Forty main ICSD centers in Japan are participating in the present study. From 2002, the JHRS began to collect ICSD patient data using website registration (termed Japanese cardiac defibrillator therapy registration, or JCDTR. This investigation aims to collect data on and investigate the general parameters of patients with ICSDs, such as clinical backgrounds of the patients, purposes of implantation, complications during the implantation procedure, and incidence of appropriate and inappropriate therapies from the ICSD. The Nippon Storm Study was planned as a sub-study of the JCDTR with focus on E-storms. We aim to achieve registration of more than 1000 ICSD patients and complete follow-up data collection, with the assumption of a 5–10% incidence of E-storms during the 2-year follow-up.

  11. Techno-economic Study

    DEFF Research Database (Denmark)

    Sigurdsson, Halldór Matthias; Point, J.C.; Million, P.

    A techno-economic model for analysing and comparing broadband deployment strategies has been established. The resulting simulation model can compare Capital Expenditure (CAPEX) of dominating broadband technologies in different types of demographic areas. The study reveals the competitiveness...... and applicability of different access technologies in the future broadband market as well as providing sensitivity analysis of the most influential factors controlling market development....

  12. A Prospective Observational Study

    African Journals Online (AJOL)

    Methods: This was a prospective, questionnaire-based observational study. Printed questionnaires were distributed to the visitors of medical, surgical and neurosurgical ICU patients to determine awareness of basic infection control practices among visitors to an ICU. All the ICU staff, including nurses, doctors, consultant ...

  13. Steam explosion studies review

    International Nuclear Information System (INIS)

    Hwang, Moon Kyu; Kim, Hee Dong

    1999-03-01

    When a cold liquid is brought into contact with a molten material with a temperature significantly higher than the liquid boiling point, an explosive interaction due to sudden fragmentation of the melt and rapid evaporation of the liquid may take place. This phenomenon is referred to as a steam explosion or vapor explosion. Depending upon the amount of the melt and the liquid involved, the mechanical energy released during a vapor explosion can be large enough to cause serious destruction. In hypothetical severe accidents which involve fuel melt down, subsequent interactions between the molten fuel and coolant may cause steam explosion. This process has been studied by many investigators in an effort to assess the likelihood of containment failure which leads to large scale release of radioactive materials to the environment. In an effort to understand the phenomenology of steam explosion, extensive studies has been performed so far. The report presents both experimental and analytical studies on steam explosion. As for the experimental studies, both small scale tests which involve usually less than 20 g of high temperature melt and medium/large scale tests which more than 1 kg of melt is used are reviewed. For the modelling part of steam explosions, mechanistic modelling as well as thermodynamic modelling is reviewed. (author)

  14. Fitzmaurice Voicework Pilot Study.

    Science.gov (United States)

    Watson, Lynn; Nayak, Sadhana

    2015-11-01

    A repeated-measures pilot study was used to investigate acoustic changes in the voices of participants in a Fitzmaurice Voicework (FV) teacher certification program. Maximum phonation time (MPT) was also measured. Eleven participants with no reported voice problems were studied. Pretraining and posttraining recordings were made of each participant. Measures of MPT were made, and the recordings were analyzed for jitter, shimmer, and noise-to-harmonics ratio (NHR). The measure of effect size for MPT was moderate, and there was an overall increase in MPT from pretraining to posttraining, with 70% of participants showing an increase in MPT. The measure of effect sizes for jitter, shimmer, and NHR were small, with measurements showing no significant changes from pretraining to posttraining. There were indications that FV training may have positive outcomes for actors and professional voice users, particularly in increasing MPT. Further studies with larger subject groups are needed to investigate the significance of the increase in MPT noted in this study and to test whether FV training can help to lower rates of shimmer and jitter. Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  15. Nuclear fuel cycle studies

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    For the metal-matrix encapsulation of radioactive waste, brittle-fracture, leach-rate, and migration studies are being conducted. For fuel reprocessing, annular and centrifugal contactors are being tested and modeled. For the LWBR proof-of-breeding project, the full-scale shear and the prototype dissolver were procured and tested. 5 figures

  16. The Study of Butterflies

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 7. The Study of Butterflies - Congregations, Courtship and Migration. Peter Smetacek. Series Article Volume 7 Issue 7 July 2002 pp 6-14. Fulltext. Click here to view fulltext PDF. Permanent link:

  17. Electric field sensor studies

    International Nuclear Information System (INIS)

    Griffith, R.D.; Parks, S.

    1977-01-01

    Above-ground intrusion sensors are reviewed briefly. Buried wire sensors are next considered; feasibility studies were conducted. A triangular system of an overhead transmitter wire exciting two buried sensor wires was developed and tested. It failed sometimes to detect a man making a broad jump. A differential receiver was developed to solve this problem

  18. Diagnostic studies in amyloidosis

    NARCIS (Netherlands)

    Hazenberg, Bouke Pier Cornelis

    2007-01-01

    In this thesis two diagnostic techniques are studied in amyloidosis. Systemic amyloidosis is characterized by deposition of amyloid fibrils (tiny fibres) throughout the body resulting in damage of vital organs. Amyloid can be detected in a tissue specimen stained with Congo red: red-stained amyloid

  19. SCA12 case study

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 88; Issue 1. Utilizing linkage disequilibrium information from Indian Genome Variation Database for mapping mutations: SCA12 case study. Samira Bahl Ikhlak Ahmed The Indian Genome Variation Consortium Mitali Mukerji. Research Article Volume 88 Issue 1 April 2009 pp 55- ...

  20. A Study in Phenomenalism

    DEFF Research Database (Denmark)

    Giles, James

    Phenomenalism is a philosophical theory of perception involving the idea that statements about material objects can be explained in terms of statements about actual and possible sense experiences. In this study James Giles explores the development of phenomenalism through the works of Locke...

  1. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Ergun Kuru; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Len Volk; Mark Pickell; Evren Ozbayoglu; Barkim Demirdal; Paco Vieira; Affonso Lourenco

    1999-10-15

    This report includes a review of the progress made in ACTF Flow Loop development and research during 90 days pre-award period (May 15-July 14, 1999) and the following three months after the project approval date (July15-October 15, 1999) The report presents information on the following specific subjects; (a) Progress in Advanced Cuttings Transport Facility design and development, (b) Progress report on the research project ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (c) Progress report on the research project ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (d) Progress report on the research project ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (e) Progress report on the research project ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Progress report on the instrumentation tasks (Tasks 11 and 12) (g) Activities towards technology transfer and developing contacts with oil and service company members.

  2. Fuel development studies

    International Nuclear Information System (INIS)

    Michel, F.

    1986-12-01

    This paper describes the main lines of the studies carried out to develop the Fast Neutron Fuel Element, from the ''SPX1-first load'' version, to progress to high performance which will be required for the project 1500 and for the fast neutron series [fr

  3. Gold induced apoptsis study

    DEFF Research Database (Denmark)

    Laustsen, Christoffer

    2008-01-01

    on a macrophage cell lines and automated image processing.   Results   Cell apoptosis study Three successful CSLM counters were constructed and one unsuccessful AMG counter were constructed for automated processing and counting. One successful sorting macro were also constructed for easy directory manipulations...

  4. Australian Film Studies.

    Science.gov (United States)

    Breen, Myles P.

    Although Australia had a vigorous film industry in the silent film era, it was stifled in the 1930s when United States and British interests bought up the Australian distribution channels and closed down the indigenous industry. However, the industry and film study have undergone a renaissance since the advent of the Labor government in 1972,…

  5. COPEWORK - COPESTRESS Workplace Study

    DEFF Research Database (Denmark)

    Ladegaard, Yun Katrine; Netterstrøm, Bo; Langer, Roy

    2012-01-01

    "COPEWORK – COPESTRESS Workplace Study" er en undersøgelse af hvad der sker på arbejdspladser, når en medarbejder sygemeldes med stress. I undersøgelsen indgik 64 ledere og arbejdsmiljørepræsentanter fra fra 38 danske arbejdspladser. Alle arbejdspladser havde haft minimum én stresssygemeldt...

  6. Low dose epidemiologic studies

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    In this chapter the BEIR committee has reviewed low-dose irradiation studies since the BEIR III report. They have considered the carcinogenic effectiveness of low-LET in populations exposed to radiation from a number of different sources: diagnostic radiography; fallout from nuclear weapons testing; nuclear installations; radiation in the workplace and high levels of natural background radiation

  7. Fiction and Organization Studies

    NARCIS (Netherlands)

    Savage, P. (Paul); J.P. Cornelissen (Joep); Franck, H. (Henrika)

    2017-01-01

    textabstractThe topic of fiction is in itself not new to the domain of organization studies. However, prior research has often separated fiction from the reality of organizations and used fiction metaphorically or as a figurative source to describe and interpret organizations. In this article, we go

  8. Planning for study abroad.

    Science.gov (United States)

    Freeman, L H; Hermann, C P

    1994-01-01

    There is more to planning for study abroad than buying airplane tickets. Providing a successful course away from the host institution requires a great deal of planning by the educator. This planning includes course development, budget, marketing, travel, housing, food, and entertainment. Careful preparation provides both the educator and student a unique and enriching experience that goes beyond the traditional course.

  9. Rockwell support studies

    International Nuclear Information System (INIS)

    Cadwell, L.L.; Cline, J.F.; Gano, K.A.; Warren, J.L.; Rogers, L.E.

    1981-01-01

    Studies performed for the Rockwell Hanford Operations (RHO) were designed to either identify the role of biota in the uptake and transport of radionuclides from low-level waste management areas or design and/or evaluate methods for reducing biological transport of radionuclides away from waste management areas

  10. Advanced commercial tokamak study

    International Nuclear Information System (INIS)

    Thomson, S.L.; Dabiri, A.E.; Keeton, D.C.; Brown, T.G.; Bussell, G.T.

    1985-12-01

    Advanced commercial tokamak studies were performed by the Fusion Engineering Design Center (FEDC) as a participant in the Tokamak Power Systems Studies (TPSS) project coordinated by the Office of Fusion Energy. The FEDC studies addressed the issues of tokamak reactor cost, size, and complexity. A scoping study model was developed to determine the effect of beta on tokamak economics, and it was found that a competitive cost of electricity could be achieved at a beta of 10 to 15%. The implications of operating at a beta of up to 25% were also addressed. It was found that the economics of fusion, like those of fission, improve as unit size increases. However, small units were found to be competitive as elements of a multiplex plant, provided that unit cost and maintenance time reductions are realized for the small units. The modular tokamak configuration combined several new approaches to develop a less complex and lower cost reactor. The modular design combines the toroidal field coil with the reactor structure, locates the primary vacuum boundary at the reactor cell wall, and uses a vertical assembly and maintenance approach. 12 refs., 19 figs

  11. Studies of exotic nuclei

    International Nuclear Information System (INIS)

    Angelique, J.C.; Orr, N.A.

    1997-01-01

    The study of the nuclei far off stability valley is of much interest for testing the nuclear models established for the stable nuclei but also for astrophysics to understand the nucleosynthesis. Experiments aim to measure the mass and lifetime, to build the decay schemes and also to study the structure and the properties of these nuclei. The radioactive beam group focused its research on light neutron-rich nuclei having a halo neutron structure. Mass measurements in N ∼ Z nuclei namely in A ∼ 60-80 proton-rich nuclei, important for understanding the rp process, are mentioned, as well as in nuclei in the 100 Sn region. In the newly obtained 26 O and 28 O nuclei the lifetimes, the probabilities of emission of one for more neutrons were determined. The data analysis has permitted to determine also for the first time the lifetimes of 27,29 F and 30 Ne. Studies of nuclei in the 100 Sn region, near the proton drip line in the ground and isomeric states are now under way. The spectroscopy (energy levels, gamma emissions, etc.) of the neutron-rich nuclei produced by the 36 S fragmentation has been carried out in 31 Ne, 17 B and 29 F. Studies by Coulomb excitation of the 2 + excited states and associated probability B (E2) in O, Ne, Ni and Zn are now analysed

  12. Soil washing treatability study

    International Nuclear Information System (INIS)

    Krstich, M.

    1995-12-01

    Soil washing was identified as a viable treatment process option for remediating soil at the FEMP Environmental Management Project (FEMP). Little information relative to the specific application and potential effectiveness of the soil washing process exists that applies to the types of soil at the FEMP. To properly evaluate this process option in conjunction with the ongoing FEMP Remedial Investigation/Feasibility Study (RI/FS), a treatability testing program was necessary to provide a foundation for a detailed technical evaluation of the viability of the process. In August 1991, efforts were initiated to develop a work plan and experimental design for investigating the effectiveness of soil washing on FEMP soil. In August 1992, the final Treatability Study Work Plan for Operable Unit 5: Soil Washing (DOE 1992) was issued. This document shall be referenced throughout the remainder of this report as the Treatability Study Work Plan (TSWP). The purpose of this treatability study was to generate data to support initial screening and the detailed analysis of alternatives for the Operable Unit 5 FS

  13. Radioactive waste repository study

    International Nuclear Information System (INIS)

    1978-11-01

    This is the second part of a report of a preliminary study for AECL. It considers the requirements for an underground waste repository for the disposal of wastes produced by the Canadian Nuclear Fuel Program. The following topics are discussed with reference to the repository: 1) geotechnical assessment, 2) hydrogeology and waste containment, 3) thermal loading and 4) rock mechanics. (author)

  14. Asian Australian Studies

    DEFF Research Database (Denmark)

    Jensen, Lars

    2008-01-01

    abstrakt til konferencepaper, der diskuterer forholdet mellem ASAL, der i mange år har tegnet australske studier med hovedvægten på litteraturstudier, og AASRN, der repræsenterer asiatisk-australske studier. AASRN er langt mere populærkulturelt, cultural studies, og tværdisciplinært orienteret, u...

  15. NGLW RCRA Storage Study

    International Nuclear Information System (INIS)

    Waters, R.J.; Ochoa, R.; Fritz, K.D.; Craig, D.W.

    2000-01-01

    The Idaho Nuclear Technology and Engineering Center (INTEC) at the Idaho National Engineering and Environmental Laboratory contains radioactive liquid waste in underground storage tanks at the INTEC Tank Farm Facility (TFF). INTEC is currently treating the waste by evaporation to reduce the liquid volume for continued storage, and by calcination to reduce and convert the liquid to a dry waste form for long-term storage in calcine bins. Both treatment methods and activities in support of those treatment operations result in Newly Generated Liquid Waste (NGLW) being sent to TFF. The storage tanks in the TFF are underground, contained in concrete vaults with instrumentation, piping, transfer jets, and managed sumps in case of any liquid accumulation in the vault. The configuration of these tanks is such that Resource Conservation and Recovery Act (RCRA) regulations apply. The TFF tanks were assessed several years ago with respect to the RCRA regulations and they were found to be deficient. This study considers the configuration of the current tanks and the RCRA deficiencies identified for each. The study identifies four potential methods and proposes a means of correcting the deficiencies. The cost estimates included in the study account for construction cost; construction methods to minimize work exposure to chemical hazards, radioactive contamination, and ionizing radiation hazards; project logistics; and project schedule. The study also estimates the tank volumes benefit associated with each corrective action to support TFF liquid waste management planning

  16. Dimethyl Ether Injection Studies

    DEFF Research Database (Denmark)

    Sorenson, Spencer C.; Glensvig, Michael; Abata, Duane L.

    1998-01-01

    A series of preliminary investigations has been performed in order to investigate the behavior of DME in a diesel injection environment. These studies have in-cluded visual observations of the spray penetration and angles for high pressure injection into Nitrogen using conventional jerk pump inje...

  17. Teaching Biblical Studies Online

    Science.gov (United States)

    Delamarter, Stephen; Gravett, Sandra L.; Ulrich, Daniel W.; Nysse, Richard W.; Polaski, Sandra Hack

    2011-01-01

    In this edited transcript of a panel at the Society of Biblical Literature (November 23, 2009, Boston, Massachusetts), five Bible scholars give brief presentations on various challenges and opportunities encountered when teaching academic biblical studies courses online in both undergraduate and theological education contexts. Each presentation is…

  18. CTR plasma engineering studies

    International Nuclear Information System (INIS)

    Miley, G.H.

    1991-01-01

    Ash (e.g. thermalized helium from D-T) buildup in a tokamak can potentially prevent ignition and seriously degrade the fusion energy gain from driven system. This problem is most pronounced as the ratio of particle/energy confinement time increases towards the neoclassical limit. Yet much improved confinement of the fuel ions is desirable for a fusion reactor. The goals of the work described here were two fold: to study the effect of helium buildup on the energy balance for a tokamak, and consider methods of active control that might be employed to alleviate the problem. We examine ash buildup effect for both D-T and D- 3 He systems. Most examples used apply to the ARIES 1 D-T reactor design and to the ARIES 3 D- 3 He design since part of this was in support of these two designs. Then we report on brief studies of two potentially attractive control methods, namely controlled sawtooth and fishbone instabilities. The concept is that sawteeth or fishbones would be used on purpose periodically in order to ''flush'' out excess ash from the fusion core. Both methods are shown to feasible and attractive. More study is needed, however, since the phenomenona in which are physically complex. Still the pay off, namely, reduced ash buildup, is exceedingly important so that such studies desires strong attention

  19. Rockwell support studies

    International Nuclear Information System (INIS)

    Cadwell, L.L.

    1980-01-01

    Studies performed for the Rockwell Hanford Operations (RHO) were designed to either (1) identify the role of biota in the uptake and transport of radionuclides from low-level waste managemnt areas or (2) design and/or evaluate methods for reducing biological transport of radionuclides away from waste management areas. The completion and publication of documents reporting the results of previous studies was also emphasized this fiscal year. Field studies were designed to characterize insect and plant communities occupying low-level waste management areas and to evaluate pond ecosystem response to herbicide application. Laboratory studies involved the examination of (1) germination response in plant species proposed for surface stabilization on burial grounds, (2) a synthetic polymer matrix as a carrier and delivery system for phytotoxins to act as a barrier to plant root penetration of shallow-land low-level waste burial sites, and (3) factors responsible for differences in radionuclide availability to plants resulting from the chemical equilibration of radionuclides occurring under field conditions

  20. Studying Variation in Tunes

    NARCIS (Netherlands)

    Janssen, B.; van Kranenburg, P.

    2014-01-01

    Variation in music can be caused by different phenomena: conscious, creative manipulation of musical ideas; but also unconscious variation during music recall. It is the latter phenomenon that we wish to study: variation which occurs in oral transmission, in which a melody is taught without the help

  1. Why Study Classical Languages?

    Science.gov (United States)

    Lieberman, Samuel

    This speech emphasizes the significance of living literatures and living cultures which owe a direct debt to the Romans and the Greeks from whom they can trace their origins. After commenting on typical rejoinders to the question "Why study classical languages?" and poking fun at those who advance jaded, esoteric responses, the author dispels the…

  2. Radioactive waste repository study

    International Nuclear Information System (INIS)

    1978-11-01

    This is the third part of a report of a preliminary study for AECL. It summarizes the topics considered in reports AECL-6188-1 and AECL-6188-2 as requirements for an undergpound repository for disposal of wastes produced by the Canadian Nuclear Fuel Program. (author)

  3. Entrepreneurship and Process Studies

    DEFF Research Database (Denmark)

    Hjorth, Daniel; Holt, Robin; Steyaert, Chris

    2015-01-01

    and potential of processual approaches to studying, researching and practising entrepreneurship. The articles in the issue attest to an increasing sensitivity to processual thinking. We argue that appreciating entrepreneurial phenomena processually opens up the field to an understanding of entrepreneurship...... as organizational creation – not simply the creation of new organizations but also experiments in new organizational form....

  4. NGLW RCRA Storage Study

    Energy Technology Data Exchange (ETDEWEB)

    R. J. Waters; R. Ochoa; K. D. Fritz; D. W. Craig

    2000-06-01

    The Idaho Nuclear Technology and Engineering Center (INTEC) at the Idaho National Engineering and Environmental Laboratory contains radioactive liquid waste in underground storage tanks at the INTEC Tank Farm Facility (TFF). INTEC is currently treating the waste by evaporation to reduce the liquid volume for continued storage, and by calcination to reduce and convert the liquid to a dry waste form for long-term storage in calcine bins. Both treatment methods and activities in support of those treatment operations result in Newly Generated Liquid Waste (NGLW) being sent to TFF. The storage tanks in the TFF are underground, contained in concrete vaults with instrumentation, piping, transfer jets, and managed sumps in case of any liquid accumulation in the vault. The configuration of these tanks is such that Resource Conservation and Recovery Act (RCRA) regulations apply. The TFF tanks were assessed several years ago with respect to the RCRA regulations and they were found to be deficient. This study considers the configuration of the current tanks and the RCRA deficiencies identified for each. The study identifies four potential methods and proposes a means of correcting the deficiencies. The cost estimates included in the study account for construction cost; construction methods to minimize work exposure to chemical hazards, radioactive contamination, and ionizing radiation hazards; project logistics; and project schedule. The study also estimates the tank volumes benefit associated with each corrective action to support TFF liquid waste management planning.

  5. Why Indigenous Nations Studies?

    Science.gov (United States)

    Porter, Robert; Yellow Bird, Michael

    2000-01-01

    The development of a new Indigenous Nations Studies program at the University of Kansas is described. Success depended on a critical mass of Indigenous and non-Indigenous faculty and students that had a sense of political and social justice and understood the need for institutional change. The biggest challenge was countering the entrenched…

  6. SOFC interface studies

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Bay, Lasse; West, Keld

    performance and inductive hysteresis phenomena often observed in SOFC kinetic studies (\\ref{TJ01}). Fig.\\,\\ref{cath_laser} shows the YSZ surface developed below a Pt point electrode polarised at -0.10\\, V at $1000^\\circ$C for a period of 85 days. The structural as well as the compositional changes...

  7. Replication studies in longevity

    DEFF Research Database (Denmark)

    Varcasia, O; Garasto, S; Rizza, T

    2001-01-01

    In Danes we replicated the 3'APOB-VNTR gene/longevity association study previously carried out in Italians, by which the Small alleles (less than 35 repeats) had been identified as frailty alleles for longevity. In Danes, neither genotype nor allele frequencies differed between centenarians and 20...

  8. national Case study

    African Journals Online (AJOL)

    This national case study reports on the development of a national network, ... system under the new policy), tends to be limited by content on problems and ... 20 credit programme; and within two Post Graduate Certificate of Education contexts, ...... descriptive with an issues focus (empirical) towards awareness production to.

  9. A Study of Sharing.

    Science.gov (United States)

    Wolff, Joseph L.; Levy, Janet

    This paper is a report of a study which explores the relative contributions of norms, modeling, positive affect, and empathy to generalized reciprocity (prior help by one person leading to greater helpfulness by the recipient toward another person). Preschool children were randomly assigned to one of six groups and individually exposed to two…

  10. SOCMA study urges flexibility

    International Nuclear Information System (INIS)

    Kirschner, E.

    1993-01-01

    In implementing the 1990 Pollution Prevention Act, regulators and legislators should hold off on cookie-cutter, numerical goal-based requirements to allow for site and process specific programs, says a study sponsored by the Synthetic Organic Chemicals Manufacturers Association (SOCMA; Washington). Companies should have that flexibility to target their resources toward those activities that reduce pollution cost effectively, says SOCMA environmental quality committee chairman Art Gillen, who is also BASF director of environmental regulatory affairs. The study - conducted by Woodward-Clyde Consultants (Denver) - examines four batch and custom chemical manufacturing films. As in the Clean Air Act, the batch processing of SOCMA-member plants should be considered in new regulations, Gillen says. For example, the study found that most wastes are from shutdowns and cleanouts, and there are frequent charges in waste streams and raw materials. Those characteristics do not lend themselves to annual reduction goals. Also, specific goals could have a wide range of costs: measures to reduce stack air emissions run from $18/lb to $1,106/lb. SOCMA says it will present the study to Congress and the Environmental Protection Agency

  11. The Study of Butterflies

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 5. The Study of Butterflies - Intra-specific Variation. Peter Smetacek. Series Article Volume 6 Issue 5 May 2001 pp 8-15. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/006/05/0008-0015 ...

  12. The Study of Butterflies

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 8. The Study of Butterflies - Flight, Fuels and Senses. Peter Smetacek. Series Article Volume 5 Issue 8 August 2000 pp 4-12. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/005/08/0004-0012 ...

  13. Belgrade metro studies

    Directory of Open Access Journals (Sweden)

    Biljana Arandjelović

    2009-01-01

    Full Text Available The subway system is an indispensable part of every modern metropolis. Building a subway is no longer a matter of prestige but a necessity, a consequence of the traffic revolution worldwide. This paper shows four metro studies with specific reference to the Belgrade subway and problems that occurred. The first one was conducted in 1946 by the famous Serbian architect Nikola Dobrovic. This document is indeed the first written record discussing the subway issue in Belgrade. The next study dates back to 1968. This project was the first major study on the possibility of a subway. The third and biggest, this subway study was completed in 1982 and contained a major and comprehensive subway project. This project was officially accepted and enacted by the city government. The fourth project in circulation with regard to the subway is the light city railway project. It came out due to the consequences of the decision that a classical subway was not necessary in Belgrade, so that a replacement for the classical subway system was to be undertaken. The light city railway project was adopted as a part of the General Urban Plan for Belgrade by the year 2021.

  14. Cementation process study

    International Nuclear Information System (INIS)

    Park, H.H.; Han, K.W.; Ahn, S.J.; Choi, K.S.; Lee, M.W.; Ryu, Y.K.

    1985-01-01

    In the cementation process study, in 1984, design of the waste treatment simulator was finished for the first step. We can experience not only the operation of solidification system but the design and construction of comming large scale plant through the design of cementation process. (Author)

  15. SOLID WASTE STUDY

    Energy Technology Data Exchange (ETDEWEB)

    PAUL G. ORTIZ - COLEMAN RESEARCH CORP/COMPA INDUSTRIES

    1995-08-01

    The purpose of this document is to study the solid waste issues brought about by a Type C Investigation; ``Disposal of Inappropriate Material in the Los Alamos County Landfill'' (May 28, 1993). The study was completed in August 1995 by Coleman Research Corporation, under subcontract number 405810005-Y for Los Alamos National Laboratory (LANL). The study confirmed the issues identified in the Type C investigation, and also ascertained further issues or problems. During the course of this study two incidents involving hazardous waste resulted in the inappropriate disposal of the waste. An accidental spill, on June 8, 1995, at one of Laboratory buildings was not handled correctly, and ended up in the LAC Landfill. Hazardous waste was disposed of in a solid waste container and sent to the Los Alamos County Landfill. An attempt to locate the hazardous waste at the LAC Landfill was not successful. The second incident involving hazardous waste was discovered by the FSS-8, during a random dumpster surveillance. An interim dumpster program managed by FSS-8 discovered hazardous waste and copper chips in the solid waste, on August 9, 1995. The hazardous waste and copper chips would have been transported to the LAC Landfill if the audit team had not brought the problem to the awareness of the facility waste management personnel.

  16. African Studies Monographs: Submissions

    African Journals Online (AJOL)

    Author Guidelines. Manuscripts should be sent to The Series Editor, African Studies Monographs, OOP Ltd, P.O. Box 4893, Somolu, Lagos State, Nigeria or Dr Karo Ogbinaka, Department of Philosophy, Faculty of Arts, University of Lagos, Akoka, Yaba, Lagos, Nigeria. Electronic submission should be on Microsoft Word and ...

  17. Speech Alarms Pilot Study

    Science.gov (United States)

    Sandor, A.; Moses, H. R.

    2016-01-01

    Currently on the International Space Station (ISS) and other space vehicles Caution & Warning (C&W) alerts are represented with various auditory tones that correspond to the type of event. This system relies on the crew's ability to remember what each tone represents in a high stress, high workload environment when responding to the alert. Furthermore, crew receive a year or more in advance of the mission that makes remembering the semantic meaning of the alerts more difficult. The current system works for missions conducted close to Earth where ground operators can assist as needed. On long duration missions, however, they will need to work off-nominal events autonomously. There is evidence that speech alarms may be easier and faster to recognize, especially during an off-nominal event. The Information Presentation Directed Research Project (FY07-FY09) funded by the Human Research Program included several studies investigating C&W alerts. The studies evaluated tone alerts currently in use with NASA flight deck displays along with candidate speech alerts. A follow-on study used four types of speech alerts to investigate how quickly various types of auditory alerts with and without a speech component - either at the beginning or at the end of the tone - can be identified. Even though crew were familiar with the tone alert from training or direct mission experience, alerts starting with a speech component were identified faster than alerts starting with a tone. The current study replicated the results from the previous study in a more rigorous experimental design to determine if the candidate speech alarms are ready for transition to operations or if more research is needed. Four types of alarms (caution, warning, fire, and depressurization) were presented to participants in both tone and speech formats in laboratory settings and later in the Human Exploration Research Analog (HERA). In the laboratory study, the alerts were presented by software and participants were

  18. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira; Lei Zhou

    2000-01-30

    This is the second quarterly progress report for Year 2 of the ACTS project. It includes a review of progress made in Flow Loop development and research during the period of time between Oct 1, 2000 and December 31, 2000. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility (Task 2: Addition of a foam generation and breaker system), (b) Research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (c) Research project (Task 7): ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (d) Research project (Task 8): ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (e) Research project (Task 9): ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (g) Research on instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), and Foam properties while transporting cuttings. (Task 12), (h) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (i) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members. The tasks Completed During This Quarter are Task 7 and Task 8.

  19. BALANOPOSTHITIS: A CLINICAL STUDY

    Directory of Open Access Journals (Sweden)

    Raju

    2015-01-01

    Full Text Available INTRODUCTION: The inflammation of the non - keratinized epithelium of the glans penis (i.e., Balanities and that of prepuce (i.e., posthitis together comprise the term Balanoposthitis. AIMS AND OBJECTIVES: To determine the aetiological and p redisposing factors for the development of Balanoposthitis, and to know its relation with venereal and non - venereal disease, local and systemic precipitatin g factors. To know the prevalence of Balanoposthitis in STD clinic. Study design - retrospective study . MATERIALS AND METHODS: The study material consists of 75 cases of balanoposthitis attending out - patient department Skin & STD clinic during a period exten din g from Feb, 1998 to Feb, 1999 . CRITERIA FOR SELECTION OF A CASE: Only those cases which have a history of redness of glans or mucous surface of prepuce, with or without genital discharge or ulcer on glans or mucosal surface of prepuce with or without discharge or growth on the penis or fissuring of fore skin were selected for the study. RESULTS: Incidence of balanoposthitis during the period from Feb. 98 to Feb.99 was – 11.53%, out of 650 new STD cases. It was observed that maximum number of pat i ents w as in the 21 - 30 age group (33.34%. The next predominant groups affected were 17 - 20 & 31 - 40 age group (20% each. The third most common age group affected was 41 - 50 (16%. In this study 69 patients (92% who presented with balanoposthitis of whatever cause were found to be uncircumcised, only 6 cases (8% were found to be circumcised. Most cases who presented with balanoposthitis gave a history of exposure to STD risk. CONCLUSIONS: Balanoposthitis is very commonly encountered condition in the STD clinics wi th a multi factorial aetiology. Infective causes dominated over the other possible causes, and 30% of the candidial infection had diabetes mellitus as a predisposing factor.

  20. Background to EOHSI study

    International Nuclear Information System (INIS)

    Granville, G.

    2004-01-01

    This paper discusses ongoing public concerns regarding the health impacts of sour gas in Pincher Creek. A description of a 90 day toxicity study on hydrogen sulfide (H 2 S) at the Chemical Industry Institute of Toxicology (CIIT) in 3 strains of rodents was presented. A decade by decade review of events concerning gas emissions was provided, including a description of the 1980s lodgepole blowout and an introduction of a sulphide network in Alberta. The creation of a joint proposal for a comprehensive health review from Alberta researchers and the Canadian Association of Petroleum Producers (CAPP) was also outlined. The 1990s heralded an increased level of public participation in sour gas developments and health and odour issues. Details of the Ludwig saga were presented as well as further research studies and the Energy and Utilities Board (EUB) protocols, processes and hearings. In the 1990s, several human volunteer studies were conducted in response to public concerns about neurotoxicity and reproductive developmental effects. After the year 2000, continued public concern has been voiced at EUB hearings and at panel reviews of health effects. It was noted that development and research data has continued to be the cause of public concern and continued calls for additional work and reviews. However, no additional hazards have been identified with ongoing human volunteer studies, environmental levels and enhanced monitors research almost complete. It was concluded that current controversy seemed to downplay or ignore much of the available science. Human and animal data has consistently revealed that there is no evidence of neuro-developmental reproductive effects. It was recommended that power plays should be avoided and that the ongoing human volunteer study should eventually provide results. tabs, figs

  1. Background to EOHSI study

    Energy Technology Data Exchange (ETDEWEB)

    Granville, G. [Environmental Occupational Health Sciences Institute, Piscataway, NJ (United States)

    2004-07-01

    This paper discusses ongoing public concerns regarding the health impacts of sour gas in Pincher Creek. A description of a 90 day toxicity study on hydrogen sulfide (H{sub 2}S) at the Chemical Industry Institute of Toxicology (CIIT) in 3 strains of rodents was presented. A decade by decade review of events concerning gas emissions was provided, including a description of the 1980s lodgepole blowout and an introduction of a sulphide network in Alberta. The creation of a joint proposal for a comprehensive health review from Alberta researchers and the Canadian Association of Petroleum Producers (CAPP) was also outlined. The 1990s heralded an increased level of public participation in sour gas developments and health and odour issues. Details of the Ludwig saga were presented as well as further research studies and the Energy and Utilities Board (EUB) protocols, processes and hearings. In the 1990s, several human volunteer studies were conducted in response to public concerns about neurotoxicity and reproductive developmental effects. After the year 2000, continued public concern has been voiced at EUB hearings and at panel reviews of health effects. It was noted that development and research data has continued to be the cause of public concern and continued calls for additional work and reviews. However, no additional hazards have been identified with ongoing human volunteer studies, environmental levels and enhanced monitors research almost complete. It was concluded that current controversy seemed to downplay or ignore much of the available science. Human and animal data has consistently revealed that there is no evidence of neuro-developmental reproductive effects. It was recommended that power plays should be avoided and that the ongoing human volunteer study should eventually provide results. tabs, figs.

  2. PET studies in epilepsy

    Science.gov (United States)

    Sarikaya, Ismet

    2015-01-01

    Various PET studies, such as measurements of glucose, serotonin and oxygen metabolism, cerebral blood flow and receptor bindings are availabe for epilepsy. 18Fluoro-2-deoxyglucose (18F-FDG) PET imaging of brain glucose metabolism is a well established and widely available technique. Studies have demonstrated that the sensitivity of interictal FDG-PET is higher than interictal SPECT and similar to ictal SPECT for the lateralization and localization of epileptogenic foci in presurgical patients refractory to medical treatments who have noncontributory EEG and MRI. In addition to localizing epileptogenic focus, FDG-PET provide additional important information on the functional status of the rest of the brain. The main limitation of interictal FDG-PET is that it cannot precisely define the surgical margin as the area of hypometabolism usually extends beyond the epileptogenic zone. Various neurotransmitters (GABA, glutamate, opiates, serotonin, dopamine, acethylcholine, and adenosine) and receptor subtypes are involved in epilepsy. PET receptor imaging studies performed in limited centers help to understand the role of neurotransmitters in epileptogenesis, identify epileptic foci and investigate new treatment approaches. PET receptor imaging studies have demonstrated reduced 11C-flumazenil (GABAA-cBDZ) and 18F-MPPF (5-HT1A serotonin) and increased 11C-cerfentanil (mu opiate) and 11C-MeNTI (delta opiate) bindings in the area of seizure. 11C-flumazenil has been reported to be more sensitive than FDG-PET for identifying epileptic foci. The area of abnormality on GABAAcBDZ and opiate receptor images is usually smaller and more circumscribed than the area of hypometabolism on FDG images. Studies have demonstrated that 11C-alpha-methyl-L-tryptophan PET (to study synthesis of serotonin) can detect the epileptic focus within malformations of cortical development and helps in differentiating epileptogenic from non-epileptogenic tubers in patients with tuberous sclerosis complex

  3. EUROv Super Beam Studies

    International Nuclear Information System (INIS)

    Dracos, Marcos

    2011-01-01

    Neutrino Super Beams use conventional techniques to significantly increase the neutrino beam intensity compared to the present neutrino facilities. An essential part of these facilities is an intense proton driver producing a beam power higher than a MW. The protons hit a target able to accept the high proton beam intensity. The produced charged particles are focused by a system of magnetic horns towards the experiment detectors. The main challenge of these projects is to deal with the high beam intensity for many years. New high power neutrino facilities could be build at CERN profiting from an eventual construction of a high power proton driver. The European FP7 Design Study EUROv, among other neutrino beams, studies this Super Beam possibility. This paper will give the latest developments in this direction.

  4. Study of different filters

    International Nuclear Information System (INIS)

    Cochinal, R.; Rouby, R.

    1959-01-01

    This note first contains a terminology related to filters and to their operation, and then proposes an overview of general characteristics of filters such as load loss with respect to gas rate, efficiency, and clogging with respect to filter pollution. It also indicates standard aerosols which are generally used, how they are dosed, and how efficiency is determined with a standard aerosol. Then, after a presentation of the filtration principle, this note reports the study of several filters: glass wool, filter papers provided by different companies, Teflon foam, English filters, Teflon wool, sintered Teflonite, quartz wool, polyvinyl chloride foam, synthetic filter, sintered bronze. The third part reports the study of some aerosol and dust separators

  5. World Biofuels Study

    Energy Technology Data Exchange (ETDEWEB)

    Alfstad,T.

    2008-10-01

    This report forms part of a project entitled 'World Biofuels Study'. The objective is to study world biofuel markets and to examine the possible contribution that biofuel imports could make to help meet the Renewable Fuel Standard (RFS) of the Energy Independence and Security Act of 2007 (EISA). The study was sponsored by the Biomass Program of the Assistant Secretary for Energy Efficiency and Renewable Energy (EERE), U.S. Department of Energy. It is a collaborative effort among the Office of Policy and International Affairs (PI), Department of Energy and Oak Ridge National Laboratory (ORNL), National Renewable Energy Laboratory (NREL) and Brookhaven National Laboratory (BNL). The project consisted of three main components: (1) Assessment of the resource potential for biofuel feedstocks such as sugarcane, grains, soybean, palm oil and lignocellulosic crops and development of supply curves (ORNL). (2) Assessment of the cost and performance of biofuel production technologies (NREL). (3) Scenario-based analysis of world biofuel markets using the ETP global energy model with data developed in the first parts of the study (BNL). This report covers the modeling and analysis part of the project conducted by BNL in cooperation with PI. The Energy Technology Perspectives (ETP) energy system model was used as the analytical tool for this study. ETP is a 15 region global model designed using the MARKAL framework. MARKAL-based models are partial equilibrium models that incorporate a description of the physical energy system and provide a bottom-up approach to study the entire energy system. ETP was updated for this study with biomass resource data and biofuel production technology cost and performance data developed by ORNL and NREL under Tasks 1 and 2 of this project. Many countries around the world are embarking on ambitious biofuel policies through renewable fuel standards and economic incentives. As a result, the global biofuel demand is expected to grow very

  6. Metabolomic studies in pulmonology

    Directory of Open Access Journals (Sweden)

    R. R. Furina

    2015-01-01

    Full Text Available The review shows the results of metabolomic studies in pulmonology. The key idea of metabolomics is to detect specific biomarkers in a biological sample for the diagnosis of diseases of the bronchi and lung. Main methods for the separation and identification of volatile organic substances as biomarkers (gas chromatography, mass spectrometry, and nuclear magnetic resonance spectrometry used in metabolomics are given. A solid-phase microextraction method used to pre-prepare a sample is also covered. The results of laboratory tests for biomarkers for lung cancer, acute respiratory distress syndrome, chronic obstructive pulmonary disease, cystic fibrosis, chronic infections, and pulmonary tuberculosis are presented. In addition, emphasis is placed on the possibilities of metabolomics used in experimental medicine, including to the study of asthma. The information is of interest to both theorists and practitioners.

  7. Botswana country study

    Energy Technology Data Exchange (ETDEWEB)

    1999-09-01

    This study was carried out in Botswana, Tanzania and Zambia as part of the project `Climate Change Mitigation in Southern Africa` funded by the Danish International Development Agency (Danida). The project was conducted parallel to the UNEP/GEF project `Economics of Greenhouse Gas Limitations` which involved 8 other developing countries and 2 regional projects in Latin America and the SADC region. The limitation of greenhouse gas (GHG) emissions is a complex issue, intimately connected with economic development at local, national, regional and global levels. Key economic sectors such as energy, agriculture, industry and forestry all produce GHGs, and are likely to be affected directly and indirectly by any mitigation policy. The UNEP Greenhouse Gas Abatement Costing Studies, initiated in 1991, attempted to address these complex issues, developing a methodological framework and testing it through practical application in ten countries. (EHS) 28 refs.

  8. Remote connector development study

    International Nuclear Information System (INIS)

    Parazin, R.J.

    1995-05-01

    Plutonium-uranium extraction (PUREX) connectors, the most common connectors used at the Hanford site, offer a certain level of flexibility in pipe routing, process system configuration, and remote equipment/instrument replacement. However, these desirable features have inherent shortcomings like leakage, high pressure drop through the right angle bends, and a limited range of available pipe diameters that can be connect by them. Costs for construction, maintenance, and operation of PUREX connectors seem to be very high. The PUREX connector designs include a 90 degree bend in each connector. This increases the pressure drop and erosion effects. Thus, each jumper requires at least two 90 degree bends. PUREX connectors have not been practically used beyond 100 (4 in.) inner diameter. This study represents the results of a survey on the use of remote pipe-connection systems in US and foreign plants. This study also describes the interdependence between connectors, remote handling equipment, and the necessary skills of the operators

  9. Studies on provoked asthma

    International Nuclear Information System (INIS)

    Munkner, L.; Bundgaard, A.

    1982-01-01

    A group of adult patients with perennial bronchial asthma has been studied as to lung perfusion and alveolar ventilation (81m-Kr) at rest and after provocation of an acute attack. Asthma was provoked by exercise and by histamine inhalation. After provocation the peak expiratory flow values were reduced to less than 80% of the base line values. Perfusion was often deranged. Regional ventilation changed rapidly after provocation and not always in the same fashion after exercise and histamine. During attacks lung volume increased. The expansion decreased (in parallel with increased peak expiratory flow) after inhalator of a #betta#-2 agonist (terbutaline). 81m-Kr offers unique opportunities for studying acute regional changes in alveolar ventilation. (Author)

  10. ATF-1 torsatron studies

    International Nuclear Information System (INIS)

    Lyon, J.F.; Carreras, B.A.; Charlton, L.A.

    1983-01-01

    The main advances in the ORNL Stellarator Program since the 1982 IAEA Conference have been: (1) engineering design of the ATF-1 torsatron; (2) extension of 3-D MHD equilibrium and stability studies and calculations of helical axis configurations; (3) study of stable equilibria with greater than or equal to 8% and direct access to the second stability regime; (4) 3-D Monte Carlo and analytic transport calculations which show a large reduction in transport at low collisionality for the absolute value of e phi'/T' greater than or equal to 1; (5) calculation of ambipolar electric fields; and (b) calculation of well confined ion drift surfaces in the ergodic field region outside the last closed flux surface

  11. LEIR longitudinal studies

    CERN Document Server

    Albright, S; Hancock, S

    2017-01-01

    Towards the end of 2015 and during 2016 there were exten-sive studies of longitudinal beam dynamics in LEIR aimedat improving extracted intensities. As the driving source oflosses early in the ramp was shown to be transverse spacecharge tune spread a significant improvement came fromflattening the beam profile to increase the bunching factorby offsetting the RF frequency from the beam revolution fre-quency. Further benefits were provided by modulating theRF frequency during capture, leading to emittance blow-upand improved reproducibility. The use of two RF cavitiesduring operation was studied to try and further increase thecaptured emittance, however after careful alignment of theRF it was found that a hard limit in the bunch heigh of approx-imately 7 MeV exists. Due to the acceptance limit there wasno operational benefit to using both cavities simultaneously

  12. Objectivist case study research

    DEFF Research Database (Denmark)

    Ridder, Hanne Mette Ochsner; Fachner, Jörg

    2016-01-01

    be achieved through the use of objectivist case study research. The strength of the case study design is that it allows for uncovering or suggesting causal relationships in real-life settings through an intensive and rich collection of data. According to Hilliard (1993), the opposite applies for extensive......In order to comprehend the impact of music therapy or music therapy processes, a researcher might look for an approach where the topic under investigation can be understood within a broader context. This calls for a rich inclusion of data and consequently a limited number of participants and may...... designs, in which a small amount of data is gathered on a large number of subjects. With the richness of data, the intensive design is ―the primary pragmatic reason for engaging in single-case or small N research‖ (p. 374) and for working from an idiographic rather than a nomothetic perspective....

  13. Case Study: Shiraz Women

    Directory of Open Access Journals (Sweden)

    Bijan Khajehnoori

    2011-04-01

    Full Text Available This study investigated the relationship between lifestyle which seems as a scale of globalization process with body image. Required data was collected by systematic random sampling among 508 women in Shiraz. Based on existing theories and studies theoretical framework has constituted based on Giddens theory. Six hypotheses have been established. For collecting information, survey method and self reported questionnaire were used. In data analysis and explanation, multiple regression and unilateral dispersion analyses were used. The result showed that among effective factors on body image, modern musical lifestyle, religious' lifestyle, leisure lifestyle and participative lifestyle explained 23 percent of variations of body image. Among these variables, only religious lifestyle had negative relationship with body image and other variables had positive relationship with dependant variable.

  14. E85 Dispenser Study

    Energy Technology Data Exchange (ETDEWEB)

    Moriarty, K.; Johnson, C.; Sears, T.; Bergeron, P.

    2009-12-01

    This study reviews E85 dispensing infrastructure advances and issues and evaluates the geographic concentration of flexible fuel vehicles (FFVs), E85 stations, ethanol production facilities, and E85 suppliers. Costs, space, financial incentives, and barriers to adding E85 fueling equipment at existing stations are also assessed. This study found that E85 is increasingly available in the U.S. in half of the states; however, the other half have minimal or no E85 fueling options. Despite these gains, E85 is only available at 1% of U.S. gasoline stations. Ethanol production reached 9.5 billion gallons in 2008, but less than 1% is consumed as E85. FFVs have not reached a significant concentration in any county, metropolitan area, or state.

  15. Center for dielectric studies

    Science.gov (United States)

    Cross, L. E.; Newnham, R. E.; Biggers, J. V.

    1984-05-01

    This report focuses upon the parts of the Center program which have drawn most extensively upon Navy funds. In the basic study of polarization processes in high K dielectrics, major progress has been made in understanding the mechanisms in relaxor ferroelectric in the perovskite structure families. A new effort is also being mounted to obtain more precise evaluation of the internal stress effects in fine grained barium titanate. Related to reliability, studies of the effects of induced macro-defects are described, and preparation for the evaluation of space charge by internal potential distribution measurements discussed. To develop new processing methods for very thin dielectric layers, a new type of single barrier layer multilayer is discussed, and work on the thermal evaporation of oriented crystalline antimony sulphur iodide describe.

  16. Studying bacterial multispecies biofilms

    DEFF Research Database (Denmark)

    Røder, Henriette Lyng; Sørensen, Søren Johannes; Burmølle, Mette

    2016-01-01

    The high prevalence and significance of multispecies biofilms have now been demonstrated in various bacterial habitats with medical, industrial, and ecological relevance. It is highly evident that several species of bacteria coexist and interact in biofilms, which highlights the need for evaluating...... the approaches used to study these complex communities. This review focuses on the establishment of multispecies biofilms in vitro, interspecies interactions in microhabitats, and how to select communities for evaluation. Studies have used different experimental approaches; here we evaluate the benefits...... and drawbacks of varying the degree of complexity. This review aims to facilitate multispecies biofilm research in order to expand the current limited knowledge on interspecies interactions. Recent technological advances have enabled total diversity analysis of highly complex and diverse microbial communities...

  17. Options Study - Phase II

    Energy Technology Data Exchange (ETDEWEB)

    R. Wigeland; T. Taiwo; M. Todosow; W. Halsey; J. Gehin

    2010-09-01

    The Options Study has been conducted for the purpose of evaluating the potential of alternative integrated nuclear fuel cycle options to favorably address the issues associated with a continuing or expanding use of nuclear power in the United States. The study produced information that can be used to inform decisions identifying potential directions for research and development on such fuel cycle options. An integrated nuclear fuel cycle option is defined in this study as including all aspects of the entire nuclear fuel cycle, from obtaining natural resources for fuel to the ultimate disposal of used nuclear fuel (UNF) or radioactive wastes. Issues such as nuclear waste management, especially the increasing inventory of used nuclear fuel, the current uncertainty about used fuel disposal, and the risk of nuclear weapons proliferation have contributed to the reluctance to expand the use of nuclear power, even though it is recognized that nuclear power is a safe and reliable method of producing electricity. In this Options Study, current, evolutionary, and revolutionary nuclear energy options were all considered, including the use of uranium and thorium, and both once-through and recycle approaches. Available information has been collected and reviewed in order to evaluate the ability of an option to clearly address the challenges associated with the current implementation and potential expansion of commercial nuclear power in the United States. This Options Study is a comprehensive consideration and review of fuel cycle and technology options, including those for disposal, and is not constrained by any limitations that may be imposed by economics, technical maturity, past policy, or speculated future conditions. This Phase II report is intended to be used in conjunction with the Phase I report, and much information in that report is not repeated here, although some information has been updated to reflect recent developments. The focus in this Options Study was to

  18. Centrifugal compressor case study

    Energy Technology Data Exchange (ETDEWEB)

    Eckert, B.

    2010-10-15

    Three centrifugal compressors at a pipeline station were retrofitted with higher head impellers in 2008. The owners of the station experienced vibration problems over the following 2 years that caused transmitter and position failures that were assumed to be flow-induced pulsations. A vibration and pulsation analysis indicated that the shell mode piping vibration excited by the blade pass pulsation was responsible for the failures. This study outlined factors that contributed to the vibration problem. Interferences between the compressor and shell mode piping natural frequencies were predicted, and potential excitation sources were examined. The study demonstrated how centrifugal vibration analyses can be used during the design phase to avoid costly adjustments. Recommendations included the addition of stiffeners to alter the shell modes, and the addition of constrained layer damping material to reduce resonant responses. 2 refs., 1 tab., 12 figs.

  19. Studies on Aspergillus flavus

    International Nuclear Information System (INIS)

    Padwal-Desai, S.R.; Ghanekar, A.S.; Sreenivasan, A.

    1976-01-01

    In vitro studies were conducted on conidia of Aspergillus flavus Link (aflatoxin producing) and Aspergillus flavus oryzae (non-toxigenic) strains isolated and identified in this laboratory. These strains differed in resistance to heat and gamma radiation, the toxigenic strain being more resistant to both treatments. Results of tests on dose-modifying factors indicated that composition, temperature and pH of suspending media affected radiation resistance. On the other hand, the size of the initial population and the age of the conidia did not influence the radiation resistance of either strain. Studies on thermal inactivation of the conidia suggested that the temperature employed was more important than the time of heat treatment. Conidia of both strains showed a synergistic effect of combined heat and radiation treatments, although a heat-radiation sequence was more effective than a radiation-heat sequence. (author)

  20. Study on market policy

    International Nuclear Information System (INIS)

    2008-02-01

    In April 2007 the Dutch Minister of Economic Affairs promised the Lower House a study of the development of the public interests of quality, accessibility and efficiency after the introduction of market liberalization. In the debate on market liberalization in May 2007 the Minister complied with the Lower House?s request to include the consequences of the market liberalization operations on sectoral employment and labor conditions. This study addresses two questions: (1) Which developments occurred in the field of public interests quality, accessibility and efficiency and labor conditions since the introduction of market liberalization? and (2) What general findings and conclusions can be drawn from the implemented market liberalization policy in various sectors? What lessons can be learned for the future? Several sectors have been examined, including large energy users; renewable energy; energy market for medium users; energy (gas and electricity) [nl