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1

Temperature and baric dependence of nuclear quadruple resonance spectra in indium and gallium monoselenides  

NASA Astrophysics Data System (ADS)

Pulsed radiospectroscopy method has been used to study nuclear quadruple resonance (NQR) spectra of 69Ga and 115In isotopes in the layered semiconductors GaSe and InSe. It has been found that in GaSe and InSe there is a considerable temperature dependence of NQR frequency which in the temperature range of 250 to 390 K is practically linear with conversion slope 1.54 kHz/degree for 69Ga and 2.35 kHz/degree for 115In. In the same crystals the effect of uniaxial pressure on NQR spectra applied along the optical axis ? up to the values of 500 kg/?m2 has been studied. A strong attenuation of NQR spectra intensity with increase in pressure on layered crystal package has been established. The unvaried multiplicity of resonance spectra indicates the absence of structural transformations in these layered crystals over the investigated range of temperatures and pressures.

Khandozhko, Victor; Raranskii, Nikolai; Balazjuk, Vitaly; Samila, Andriy; Kovalyuk, Zahar

2013-12-01

2

NQR and Raman spectroscopy study of ?-dichlorobiphenyl  

Microsoft Academic Search

Pulsed 0953-8984\\/8\\/21\\/016\\/img9 nuclear quadrupole resonance (NQR) and Raman spectroscopy studies were performed to get information about the structural and dynamic thermal behaviour of the 0953-8984\\/8\\/21\\/016\\/img10 dichlorobiphenyl. NQR measurements of the line-shape and the spin - lattice relaxation time 0953-8984\\/8\\/21\\/016\\/img11 were obtained in the temperature range 80 K - 320 K. Raman spectra from powder samples were recorded for temperatures between

J. Schneider; A. Wolfenson; A. Brunetti; L. A. de O. Nunes

1996-01-01

3

101Ru NQR study in CeRu 2  

NASA Astrophysics Data System (ADS)

We present measurements of the NQR spectrum and the nuclear spin lattice relaxation rate, 1/ T1, of 101Ru in superconducting CeRu 2 from 1.9 K to 10 K. From the NQR spectrum, the electric quadrupole interaction parameters were determined to be ?Q = 13.2 MHz and ? = 0.1/ T1 varies in proportion to temperature in the normal state, has the Hebel-Slichter coherence peak just below the superconducting transition temperature, TC, of 6.2 K, and decreases exponentially at low temperatures with the energy gap of 2 ? = 4.0 kBTC. 101Ru NQR study indicates that CeRu 2 is an s-wave and strong-coupling superconductor.

Matsuda, K.; Kohori, Y.; Kohara, T.

1996-02-01

4

Partial disorder and molecular motion of 4-chlorobiphenyl studied by 35Cl NQR and Raman spectroscopy  

Microsoft Academic Search

Pulsed 35Cl nuclear quadrupole resonance (NQR) and Raman spectroscopy studies were performed to get information about the structural and dynamic thermal behavior of the 4-chlorobiphenyl. NQR measurements of the line shape and the spin-lattice relaxation time (T1) were obtained in the temperature range 80-320 K. An inhomogeneously broadened NQR line shape was observed, suggesting a disordered structure in all the

J. Schneider; A. Wolfenson; C. Schürrer; A. Brunetti; L. A. de O. Nunes

1996-01-01

5

Thermal hysteresis in 4,4' dichlorobenzophenone studied by 35Cl NQR  

Microsoft Academic Search

A pulsed NQR study of 4,4' dichlorobenzophenone has been performed to get information about dynamic features in its three crystalline phases. The authors found in phases I (T>190 K) and III (T<180 K) a normal thermal behaviour of the NQR frequency and spin-lattice relaxation time. In the intermediate phase II (180 KNQR parameters could

J. F. Schneider; A. E. Wolfenson; A. H. Brunetti

1992-01-01

6

Copper valence, structural separation and lattice dynamics in tennantite (fahlore): NMR, NQR and SQUID studies  

NASA Astrophysics Data System (ADS)

Electronic and magnetic properties of tennantite subfamily of tetrahedrite-group minerals have been studied by copper nuclear quadrupole resonance (NQR), nuclear magnetic resonance (NMR) and SQUID magnetometry methods. The temperature dependences of copper NQR frequencies and line-width, nuclear spin-lattice relaxation rate T {1/-1} and nuclear spin-echo decay rate T {2/-1} in tennantite samples in the temperature range 4.2-210 K is evidence of the presence of field fluctuations caused by electronic spins hopping between copper CuS3 positions via S2 bridging atom. The analysis of copper NQR data at low temperatures points to the magnetic phase transition near 65 K. The magnetic susceptibility in the range 2-300 K shows a Curie-Weiss behavior, which is mainly determined by Fe2+ paramagnetic substituting ions.

Gainov, R. R.; Dooglav, A. V.; Pen'kov, I. N.; Mukhamedshin, I. R.; Savinkov, A. V.; Mozgova, N. N.

2008-01-01

7

Gapless superconductivity in overdoped Hg System; Cu-NQR study  

Microsoft Academic Search

The nuclear quadrupole resonance (NQR) investigation of Cu in the overdoped compounds HgBa2CuOy (Hg1201) with y=4. 06 (Tc=92K) and 4.11 (64K) and HgBa2CaCu2Oy (Hg1212) with y=6.13 (Tc=125K) and 6.21 (117K) was carried out in zero field. From the temperature (T) dependence of the nuclear spin-lattice relaxation time, T1, of63Cu, we discuss a cause of the Tc suppression with decreasing the

Shigeki Ohsugi; Tetsuo Tsuchiya; Tadashi Koyama; Kazuo Fueki

1996-01-01

8

Methyl quantum tunneling and nitrogen-14 NQR NMR studies using a SQUID magnetic resonance spectrometer  

SciTech Connect

Nuclear Magnetic Resonance (NMR) and Nuclear Quadrupole Resonance (NQR) techniques have been very successful in obtaining molecular conformation and dynamics information. Unfortunately, standard NMR and NQR spectrometers are unable to adequately detect resonances below a few megahertz due to the frequency dependent sensitivity of their Faraday coil detectors. For this reason a new spectrometer with a dc SQUID (Superconducting Quantum Interference Device) detector, which has no such frequency dependence, has been developed. Previously, this spectrometer was used to observe {sup 11}B and {sup 27}Al NQR resonances. The scope of this study was increased to include {sup 23}Na, {sup 51}V, and {sup 55}Mn NQR transitions. Also, a technique was presented to observe {sup 14}N NQR resonances through cross relaxation of the nitrogen polarization to adjacent proton spins. When the proton Zeeman splitting matches one nitrogen quadrupoler transition the remaining two {sup 14}N transitions can be detected by sweeping a saturating rf field through resonance. Additionally, simultaneous excitation of two nitrogen resonances provides signal enhancement which helps to connect transitions from the same site. In this way, nitrogen-14 resonances were observed in several amino acids and polypeptides. This spectrometer has also been useful in the direct detection of methyl quantum tunneling splittings at 4.2 K. Tunneling, frequencies of a homologous series of carboxylic acids were measured and for solids with equivalent crystal structures, an exponential correlation between the tunneling frequency and the enthalpy of fusion is observed. This correlation provides information about the contribution of intermolecular interactions to the energy barrier for methyl rotation.

Black, B.E. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley Lab., CA (United States)

1993-07-01

9

NMR and NQR studies of quadrupolar effects in glasses and polycrystals with half-integer spins  

NASA Astrophysics Data System (ADS)

NMR and NQR techniques have been used in the present study to investigate glasses and polycrystalline compounds containing nuclei with half-integer spins such as: sp{11}B, sp{23}Na, sp{45}Sc, and sp{93}Nb. The low field ({˜}1.2{-}1.5 Tesla) continuous wave (CW) NMR experiments were performed using the Non-Adiabatic Superfast Passage (NASP) or the slow passage methods. A BRUKER MSL 300 pulsed NMR spectrometer was used for the high field (7.1 Tesla) studies. The CW NQR experiments at room and liquid nitrogen temperature were carried out on a home built Robinson-type spectrometer. Using pulsed NMR the sp{45}Sc response from the glass system CaO-Bsb2Osb3-Scsb2Osb3, yielded a first-order quadrupolar interaction with eta=0 and Qsb{cc}?617 kHz. A new Sc site with Qsb{cc}=23.44 MHz and eta=0 was found in polycrystalline Scsb2Osb3 and it was confirmed by NQR. Employing the NASP method it was found that the fraction of four-coordinated (Nsb4) boron atoms in the alkali thioborate (Nasb2S-Bsb2Ssb3) glass system follows a 3x/(1 - x) relationship for x?0.15, where x is the molar fraction of Nasb2S in the glass. For the NQR spectra the 10% Nasb2S content glass exhibited a broader NQR resonance than the NQR resonance for pure v-Bsb2Ssb3. The additional width was attributed to responses of BSsb3 units whose Qsb{cc} values differ somewhat from the BSsb3 units in the pure vitreous Bsb2Ssb3. The CW NASP method was used to study the sp{23}Na response in the Nasb2O*2SiOsb2 glass, heat treated in three ways: annealed, slow cooled and splat quenched. Subjecting the glass to rapid cooling will produce an increased range of values for the components of the electric field gradient (EFG), and, hence an increased range of values for Qsb{cc} and eta. This was observed for the slow cooled sample when compared with the annealed glass. The effect should be seen also from the slow cooled to the splat quenched sample, but this was not observed. Crystalline sodium disilicate was examined by both NMR and NQR and yielded Qsb{cc} = 1.89 MHz for sp{23}Na and eta=0.9. Furthermore the response from sp{23}Na in the polycrystalline forms of sodium molybdate, sodium tungstate, sodium stanate and albite was examined by means of NASP, pulsed NMR, and NQR. The sp{23}Na spectra for these compounds yielded values of Qsb{cc}, in the range 2.56 MHz to 2.80 MHz. A computer simulation program was used to simulate the spectra of sp{93}Nb-containing compounds. The survey of the niobium response in various polycrystalline compounds using the pulse-echo technique revealed first-order and second-order quadrupolar effects. The sp{93}Nb responses from five glasses in the Nbsb2Osb5-Nasb2O-SiOsb2 ternary glass system produced a second-order quadrupole pattern, but the response might contain more than one Nb site.

Orengo-Aviles, Moises

10

Solid-state NMR/NQR and first-principles study of two niobium halide cluster compounds.  

PubMed

Two hexanuclear niobium halide cluster compounds with a [Nb6X12](2+) (X=Cl, Br) diamagnetic cluster core, have been studied by a combination of experimental solid-state NMR/NQR techniques and PAW/GIPAW calculations. For niobium sites the NMR parameters were determined by using variable Bo field static broadband NMR measurements and additional NQR measurements. It was found that they possess large positive chemical shifts, contrary to majority of niobium compounds studied so far by solid-state NMR, but in accordance with chemical shifts of (95)Mo nuclei in structurally related compounds containing [Mo6Br8](4+) cluster cores. Experimentally determined ?iso((93)Nb) values are in the range from 2,400 to 3,000 ppm. A detailed analysis of geometrical relations between computed electric field gradient (EFG) and chemical shift (CS) tensors with respect to structural features of cluster units was carried out. These tensors on niobium sites are almost axially symmetric with parallel orientation of the largest EFG and the smallest CS principal axes (Vzz and ?33) coinciding with the molecular four-fold axis of the [Nb6X12](2+) unit. Bridging halogen sites are characterized by large asymmetry of EFG and CS tensors, the largest EFG principal axis (Vzz) is perpendicular to the X-Nb bonds, while intermediate EFG principal axis (Vyy) and the largest CS principal axis (?11) are oriented in the radial direction with respect to the center of the cluster unit. For more symmetrical bromide compound the PAW predictions for EFG parameters are in better correspondence with the NMR/NQR measurements than in the less symmetrical chlorine compound. Theoretically predicted NMR parameters of bridging halogen sites were checked by (79/81)Br NQR and (35)Cl solid-state NMR measurements. PMID:24581866

Peri?, Berislav; Gautier, Régis; Pickard, Chris J; Bosio?i?, Marko; Grbi?, Mihael S; Požek, Miroslav

2014-01-01

11

NQR Spin--Echo Double Resonance (SEDOR) Study of Interplane Coupling in Y_2Ba_4Cu_7O_15  

NASA Astrophysics Data System (ADS)

We report a detailed spin--echo double resonance study(R. Stern, M. Mali, J. Roos, and D. Brinkmann, Phys. Rev. B 52), (in press). of the planar Cu sites in Y_2Ba_4Cu_7O_15 above Tc employing nuclear quadrupole resonance (NQR). Due to the alternation of YBa_2Cu_3O7 and YBa_2Cu_4O8 blocks in its structure the individual planes of a CuO2 double plane in Y_2Ba_4Cu_7O_15 are inequivalent and hence can separately be monitored by NMR/NQR methods.(R. Stern et al.), Phys. Rev. B 50, 426 (1994), ibid. 51, 15478 (1995). The experiments directly reveal the coupling between the inequivalent single planes of a double CuO2 plane. The ratio of particular NQR relaxation rates is a measure for the strength of this interplane coupling with respect to the intraplane coupling. This ratio increases with decreasing temperature. Using recent calculations by Millis and Monien,(A. J. Millis and H. Monien, cond-mat # 9506088.) an interplane coupling constant of about 5 meV is deduced.

Stern, Raivo

1996-03-01

12

NQR investigation and characterization of cocrystals and crystal polymorphs  

NASA Astrophysics Data System (ADS)

The application of 14N NQR to the study of cocrystals and crystal polymorphs is reviewed. In ferroelectric and antiferroelectric organic cocrystals 14N NQR is used to determine proton position in an N-H...O hydrogen bond and proton displacement below TC. In cocrystal isonicitinamide - oxalic acid (2:1) 14N NQR is used to distinguish between two polymorphs and to determine the type of the hydrogen bond (N-...H-O). The difference in the 14N NQR spectra of cocrystal formers and cocrystal is investigated in case of carbamazepine, saccharin and carbamazepine - saccharin (1:1). The experimental resolution allows an unambiguous distinction between the 14N NQR spectrum of the cocrystal and the 14N NQR spectra of the cocrystal formers. The possibility of application of NQR and double resonance for the determination of the inhomogeneity of the sample and for the study of the life time of an unstable polymorph is discussed.

Seliger, Janez; Žagar, Veselko; Asaji, Tetsuo

2013-05-01

13

Electron density distribution in cladribine (2-chloro-2?-deoxyadenosine) - A drug against leukemia and multiple sclerosis - Studied by multinuclear NQR spectroscopy and DFT calculations  

NASA Astrophysics Data System (ADS)

2-Chloro-2'-deoxyadenosine (Cladribine) chemotherapeutic drug has been studied experimentally in solid state by 35Cl NQR and NMR-NQR double resonance and theoretically by the Density Functional Theory. Fifteen resonance frequencies on 14N have been detected and assigned to particular nitrogen sites in the 2-CdA molecule. The effects of tautomerism, regioisomerism, conformations and molecular aggregations, related to intermolecular hydrogen bond formation, on the NQR parameters have been analysed within the DFT and AIM ( Atoms in Molecules) formalism. The properties of the whole molecule, the so-called global reactivity descriptors, have been calculated for a comparison of both syn and anti conformations of 2-CdA molecule to check the effect of crystal packing on molecular conformation.

Latosi?ska, J. N.; Latosi?ska, M.; Seliger, J.; Žagar, V.; Kazimierczuk, Z.

2009-07-01

14

NQR Spin--Echo Double Resonance (SEDOR) Study of Interplane Coupling in Y_2Ba_4Cu_7O_15  

Microsoft Academic Search

We report a detailed spin--echo double resonance study(R. Stern, M. Mali, J. Roos, and D. Brinkmann, Phys. Rev. B 52), (in press). of the planar Cu sites in Y_2Ba_4Cu_7O_15 above Tc employing nuclear quadrupole resonance (NQR). Due to the alternation of YBa_2Cu_3O7 and YBa_2Cu_4O8 blocks in its structure the individual planes of a CuO2 double plane in Y_2Ba_4Cu_7O_15 are inequivalent

Raivo Stern

1996-01-01

15

Ru-NQR Study for Novel Phase Transition in CeRu2Al10  

NASA Astrophysics Data System (ADS)

We have performed Ru-NQR measurements on CeRu2Al10 exhibiting novel phase transition at an abnormally high temperature T0 = 27.3 K and on NdRu2Al10 with a magnetic transition temperature Tm = 2.4 K as a reference RKKY system. The splitting of the NQR line due to internal fields below T0 shows a mean-field-like monotonic increase, indicating no change in the magnetic structure below T0. The internal field strength is one order larger than those at Al sites in CeRu2Al10, and is comparable to that at the Ru site in NdRu2Al10 despite the sevenfold smaller magnitude of the 4f moment, being indicative of an enhanced conduction electron polarization at the Ru site. One of the causes of the high T0 might be the enhanced exchange coupling through the Ce–Ru–Ce path mediated by the enhanced conduction electron polarization. Being similar to that in the Al site, the nuclear spin–lattice relaxation rate 1/T1 shows a gap-like decrease below T0 without enhancement owing to a critical slowing down at T0, in contrast to the mean field 2nd-order transition.

Matsumura, Masahiro; Tomita, Naoya; Matsuoka, Junichirou; Kishimoto, Yasuki; Kato, Harukazu; Kitagawa, Kentaro; Nishioka, Takashi; Tanida, Hiroshi; Sera, Masafumi

2014-10-01

16

Conformational isomerism of methyl dichloroacetate. An infrared, Raman and 35Cl NQR study  

NASA Astrophysics Data System (ADS)

The IR and Raman spectra of methyl dichloroacetate (M-DCA) have been recorded on the liquid, glassy and crystalline states. The vibrational assignment for M-DCA is proposed on the basis of the spectral comparisons between CCl nH 3? n COOCH 3 and CCl nH 5? n CONHCH 5 ( n = 0-3) in the solid state. The observed spectral data indicate that M-DCA exists as a conformational equilibrium in the liquid and in the glassy state and that the conformation in the crystalline state is entirely different from those in the liquid and glassy states. The 35Cl NQR spectrum suggests that the conformation of M-DCA in the crystalline state is the cis form in which one of the two chlorine atoms is located in the cis position with respect to the carbonyl group. Examination of vibrational spectra also leads to the same conclusion.

Mido, Yoshiyuki; Hashimoto, Masao

1985-10-01

17

Studies of the electronic structure and biological activity of chosen 1,4-benzodiazepines by 35Cl NQR spectroscopy and DFT calculations  

NASA Astrophysics Data System (ADS)

Selected derivatives of 1,4-benzodiazepine: lorazepam, lormetazepam, oxazepam and temazepam, used as active substances in anxiolytic drugs, have been studied by 35Cl NQR method in order to find the correlation between electronic structure and biological activity. The 35Cl NQR resonance frequencies ( ?Q) measured at 77 K have been correlated with the following parameters characterising their biological activity: biological half-life period ( t0.5), affinity to benzodiazepine receptor (IC 50) and mean dose equivalent. The results of experimental study of some benzodiazepine derivatives by nuclear quadrupole resonance of 35Cl nuclei are compared with theoretical results based on DFT calculations which were carried out by means of Gaussian'98 W software.

Bronisz, K.; Ostafin, M.; Poleshchuk, O. Kh.; Mielcarek, J.; Nogaj, B.

2006-11-01

18

1H NMR and 14N NQR study of the ferroelectric phase transition in (CH3)2NH2H2PO4  

Microsoft Academic Search

The ferroelectric phase transition in (CH3)2NH2H2PO4 has been studied by 14N nuclear-quadrupole resonance (NQR) and 1H spin-lattice relaxation. Both above and below TC, the 14N quadrupole coupling constant is approximately 1.2 MHz and the asymmetry parameter eta is close to 1. Two nonequivalent nitrogen positions in the unit cell are observed below TC whereas, above TC, all nitrogen crystallographic positions

J. Seliger; V. Zagar

1998-01-01

19

Studies of Ga NMR and NQR in SrGa4  

NASA Astrophysics Data System (ADS)

In order to microscopically investigate the properties in SrGa4, the Ga NMR measurements of a powder sample were carried out. The Ga NMR spectra corresponding to Ga(I) and Ga(II) sites are obtained. The NMR spectra of 69&71Ga (a nuclear spin I = 3/2) in the powder sample of SrGa4 do not take a typical powder pattern caused by the NQR interaction, but take the spectra consisting of three well resolved resonance-lines, which indicates that the nonuniform distribution of crystal orientation in the powder sample occurs because of the magnetic anisotropy. From the analysis of the Ga NMR spectrum, it is found that the ab-plane of the crystal is parallel to the external magnetic field, which would be attributed to the anisotropy of the magnetic susceptibility with the easy axis parallel to the ab-plane. This result is also confirmed by the 69Ga NQR in SrGa4. The Knight shifts of the 69Ga(I) and 69Ga(II) shift slightly to the negative side with decreasing temperature due to the core polarization of the d-electrons. The values of the Knight shift of the 69Ga(I) and 69Ga(II) are 0.01 and -0.11 % at 4.2 K, and 0.09 and -0.08 % at 300 K, respectively. The values of the 1/ T 1 T of the NMR of both 69Ga(I) and 69Ga(II) are almost constant between 4.2 and 100 K, whose values are 1.5 s -1 K -1 at 69Ga(I) and 0.12 s -1 K -1 at 69Ga(II), while the 1/ T 1 T slightly increase above 100K with increasing temperature. The value of T 1 of 69Ga(I) is one order of magnitude less than that of 69Ga(II).

Niki, H.; Higa, N.; Nakamura, S.; Kuroshima, H.; Toji, T.; Yogi, M.; Nakamura, A.; Hedo, M.; Nakama, T.; ?nuki, Y.; Harima, H.

2014-11-01

20

35Cl NQR study of lattice dynamic and magnetic property of a crystalline coordination polymer {CuCA(phz)(H 2O) 2} n  

NASA Astrophysics Data System (ADS)

Copper(II) compounds {CuCA(phz)(H 2O) 2} n (H 2CA = chloranilic acid, phz = phenazine) having a layer structure of -CuCA(H 2O) 2- polymer chains and phenazine were studied by 35Cl nuclear quadrupole resonance (NQR). The single NQR line observed at 35.635 MHz at 261.5 K increased to 35.918 MHz at 4.2 K. The degree of reduction of electric field gradient due to lattice vibrations was similar to that of chloranilic acid crystal. Temperature dependence of spin-lattice relaxation time, T1, of the 35Cl NQR signal below 20 K, between 20 and 210 K, and above 210 K, was explained by (1) a decrease of effective electron-spin density caused by antiferromagnetic interaction, (2) a magnetic interaction between Cl nuclear-spin and electron-spins on paramagnetic Cu(II) ions, and (3) an increasing contribution from reorientation of ligand molecules, respectively. The electron spin-exchange parameter ? J? between the neighboring Cu(II) electrons was estimated to be 0.33 cm -1 from the T1 value of the range 20-210 K. Comparing this value with that of J = -1.84 cm -1 estimated from the magnetic susceptibility, it is suggested that the magnetic dipolar coupling with the electron spins on Cu(II) ions must be the principal mechanism for the 35Cl NQR spin-lattice relaxation of {CuCA(phz)(H 2O) 2} n but a delocalization of electron spin over the chloranilate ligand has to be taken into account.

Gotoh, Kazuma; Terao, Takeshi; Asaji, Tetsuo

2007-01-01

21

Effect of the oxygen protonation on the electronic structure of urea in the solid state: A 14N NQR study  

NASA Astrophysics Data System (ADS)

The 14N NQR frequencies of urea complexes with H2O2 (1:1), NH4Cl (1:1), oxalic (2:1), phosphoric (1:1), and nitric acid (1:1) at 77 °K are reported. The analysis of the NQR data indicates that the population of the N nonbonding orbital decreases and that the population of the s N-H and N-C bonds increases as the degree of protonation of the O atom of urea increases. These changes are consistent with a larger weight of structures like C = N+H2 as the protonation increases. The NQR results are in agreement with those obtained from a CNDO/2 calculation for the uronioum ion [Yu. A. Panteleev and A. A. Lipovskii, Zhu. Struk. Khim. 17, 2 (1976)].

Murgich, Juan; Santana R., Magaly

1981-04-01

22

Intensity of NQR lines for integer spins  

NASA Astrophysics Data System (ADS)

Because of the publication of contradictory information demonstrating an incorrect approach to the modeling of NQR-NMR frequency-intensity spectra of integral-spin isotopes (for example, boron-10), we study the NQR-NMR double resonance with level crossing (DRLC) in10B-1H,11B-1H,59K-1H and23Na-1H in crystal hydrates of sodium tetraborate (Na2B4O7·10H2O) and potassium tetraborate (K2B4O7·4H2O) and the results of the measurements are compared with theoretical calculations. The fact that for a system including three elements-quadrupole (NQR), Zeeman (NMR), and dipole-dipole, which establishes the interaction of the first two- the intensities of the lines in double resonance spectra are determined both by the equations of balance of the populations of the levels of the quadrupole and Zeeman reservoirs and by the probabilities of transitions within each reservoir is taken into account in the calculations. The distortion of the energy levels of the NQR subsystem by the magnetic field in the process of level crossing with the NMR subsystem is taken into account.

Anferov, V. P.; Beloglazov, G. S.; Grechishkin, V. S.

1986-12-01

23

115In-NQR study of CeRh1-xIrxIn5 under pressure  

NASA Astrophysics Data System (ADS)

We report on pressure-induced evolutions of antiferromagnetic spin fluctuations (AFM-SFs) and unconventional superconductivity on the x=0.6 sample in a series of compounds CeRh1-xIrxIn5 via the 115In nuclear-quadrupole-resonance (NQR) experiment. The In-NQR 1/T1 measurements have revealed that the slight application of pressure makes Tc=0.9 K at P=0 increase up to Tc=1.06 K at P=0.47 GPa. Concomitantly, the character of AFM-SF evolves from an isotropic regime to an anisotropic one as P increases. These results suggest that AFM-SFs play vital role in mediating the strong-coupling superconductivity in CeRh1-xIrxIn5.

Mugino, Y.; Kawasaki, S.; Yashima, M.; Mukuda, H.; Kitaoka, Y.; Shishido, H.; ?nuki, Y.

2007-03-01

24

A study of hydrogen bond of imidazole and its 4-nitro derivative by ab initio and DFT calculated NQR parameters  

NASA Astrophysics Data System (ADS)

Nuclear quadrupole resonance (NQR) parameters of 14N, 2H of N 2H groups are calculated for imidazole and 4-nitroimidazole using HF and B3LYP methods. These computations are performed on the basis of X-ray and neutron diffraction structural data which are collected at 100, 103, 123 and 293 K temperatures. In order to take into account intermolecular hydrogen bonds and the van der Waals effects, two different sizes of clusters have been considered. Results of calculation have been compared with that of a single molecule in each case. Calculations illustrate that for imidazole and 4-nitroimidazole octameric and trimeric clusters, respectively, suffice to generate results which are compatible with experimental data. Our calculated NQR parameters and X-ray data show no significant structural change for 4-nitroimidazole at 293 and 100 K.

Amini, S. K.; Hadipour, N. L.; Elmi, F.

2004-06-01

25

1H NMR and 14N NQR study of the ferroelectric phase transition in (CH3)2NH2H2PO4  

NASA Astrophysics Data System (ADS)

The ferroelectric phase transition in (CH3)2NH2H2PO4 has been studied by 14N nuclear-quadrupole resonance (NQR) and 1H spin-lattice relaxation. Both above and below TC, the 14N quadrupole coupling constant is approximately 1.2 MHz and the asymmetry parameter ? is close to 1. Two nonequivalent nitrogen positions in the unit cell are observed below TC whereas, above TC, all nitrogen crystallographic positions are equivalent. Proton spin-lattice relaxation times T1 and T1D show the presence of two molecular motions. Both below and above TC, proton T1 as measured at ?L=32 MHz is dominated by a motion that slows down on the NMR frequency scale below -100 °C. This motion is most probably the 180° reorientation of a dimethylammonium ion around its twofold axis. In the paraelectric phase we observed a slow motion dominating T1D and T1 at low Larmor frequencies. This motion seems to be an up-down reorientation of a dimethylammonium ion along its twofold axis. The NMR and NQR data are interpreted in a model assuming close similarities between the crystal structures of KH2PO4 and (CH3)2NH2H2PO4.

Seliger, J.; Žagar, V.

1998-04-01

26

79 Br and 127 I nqr spectra in series of acetylene derivatives  

Microsoft Academic Search

The complete79Br and127I NQR spectra of a number of bromo and iodo derivatives of acetylene were studied for the first time, and the field constants of the NQR frequencies were determined. It was found that the asymmetry parameters in them are low. Changes in the field constants are determined by the competing conjugation of the iodine atom and the corresponding

G. K. Semin; S. A. Petukhov; S. I. Gushchin; I. R. Gol'ding; E. V. Bryukhova; A. M. Sladkov

1983-01-01

27

Explosives detection by nuclear quadrupole resonance (NQR)  

NASA Astrophysics Data System (ADS)

Pure nuclear quadrupole resonance (NQR) of 14N nuclei is quite promising as a method for detecting explosives such as RDX and contraband narcotics such as cocaine and heroin in quantities of interest. Pure NQR is conducted without an external applied magnetic field, so potential concerns about damage to magnetically encoded data or exposure of personnel to large magnetic fields are not relevant. Because NQR frequencies of different compounds are quite distinct, we do not encounter false alarms from the NQR signals of other benign materials. We have constructed a laboratory prototype NQR explosives detector which interrogates a volume of 300 liters (10 ft3). This paper presents abbreviated results from a demonstration of the laboratory prototype NQR explosives detector conducted at the Federal Aviation Administration Technical Center in May 1994 on RDX-based explosives.

Garroway, Allen N.; Buess, Michael L.; Yesinowski, James P.; Miller, Joel B.; Krauss, Ronald A.

1994-10-01

28

Field constants of 79 Br and 127 I NQR of halogen derivatives of carbon  

Microsoft Academic Search

A study has been made of the NQR frequency field constants for the chlorine, bromine, and iodine atoms. It has been shown that the degree to which the field constants are characteristic decreases in the series Cl-Br-I.

S. A. Petukhov; E. V. Bryukhova; G. K. Semin; A. A. Boguslavskii

1984-01-01

29

SQUID detected NMR and NQR  

Microsoft Academic Search

The dc Superconducting QUantum Interference Device (SQUID) is a sensitive detector of magnetic flux, with a typical flux noise of the order 1 ??0 Hz?1\\/2 at liquid helium temperatures. Here ?0=?\\/2e is the flux quantum. In our NMR or NQR spectrometer, a niobium wire coil wrapped around the sample is coupled to a thin film superconducting coil deposited on the

Matthew P. Augustine; Dinh M. TonThat; John Clarke

1998-01-01

30

The incommensurate phase of 4,4'-dichlorobiphenyl sulphone reinvestigated by 35Cl NQR  

Microsoft Academic Search

In order to acquire new information about the normal-incommensurate (IC) phase transition and to check the existence of a lock-in transition in 4,4'-dichlorobiphenyl sulphone (4,4'-DCBS), a comprehensive 35Cl nuclear quadrupole resonance (NQR) study is reported. Detailed NQR measurements of frequency, line width and spin relaxation time (Tl) were obtained in the temperature range 80-270 K. The results show that the

J. Schneider; A. Wolfenson; A. Brunetti

1994-01-01

31

Hydrogen transfer in hydrogen-bonded chloranilic acid studied by 35Cl NQR I - a 1:2 complex with 1,4-diazine  

NASA Astrophysics Data System (ADS)

35Cl NQR frequencies and spin-lattice relaxation time ( T1Q) and 1H NMR relaxation times ( T1H) in a H-bonded three molecular system, chloranilic acid-1,4-diazine (1:2) were measured to reveal H-motions in a symmetric two H-bonds in solid. A single 35Cl NQR frequency observed implies that the time-averaged structure of chloranilic acid is roughly monovalent in accordance with p Ka values in both acid and base. T1H temperature dependence was explained by a single relaxation mechanism due to the correlated H-transfer in two H-bonds, while that of T1Q yielded two relaxation processes. One of these undetected by 1H NMR was explained by the uncorrelated H-transfer.

Nihei, Taka-aki; Ishimaru, Shin'ichi; Ishida, Hiroyuki; Ishihara, Hideta; Ikeda, Ryuichi

2000-10-01

32

Charge-carrier density and interplane coupling in Y2Ba4Cu7O15: A Cu NMR-NQR study  

NASA Astrophysics Data System (ADS)

We report an observation of the 63,65Cu nuclear quadrupole resonance (NQR) and nuclear magnetic resonance (NMR) in Y2Ba4Cu7O15. We have measured the temperature dependence of the Cu NQR frequency and spin-lattice relaxation at all four chemically inequivalent Cu sites, and of the Cu magnetic shift at two inequivalent plane Cu sites (for the magnetic field parallel and perpendicular to the c axis). The Y2Ba4Cu7O15 compound turns out to be a structure containing two inequivalent CuO2 planes of differing doping levels, a multilattice in which YBa2Cu4O8 blocks and YBa2Cu3O7 blocks alternate. In the normal conducting state both the static and the dynamic electron spin susceptibilities of the individual planes of a double plane are governed by the same temperature dependence, which shows a behavior typical for an underdoped high-Tc compound. The same temperature dependence means strong coupling between these planes, with the lower limit of the coupling constant not much less than 30 meV. Although the planes are strongly coupled, their spin susceptibilities retain a distinct q dependence. The temperature variation of relaxation rate and Knight shift is described in terms of spin-gap formation or, alternatively, of frustrated phase separation. Below Tc, the common temperature dependence is lost, which could arise from the opening of two superconducting gaps that differ in the individual planes.

Stern, R.; Mali, M.; Mangelschots, I.; Roos, J.; Brinkmann, D.; Genoud, J.-Y.; Graf, T.; Muller, J.

1994-07-01

33

35Cl NQR of an organic ferroelectric phenazine chloranilic acid co-crystal  

NASA Astrophysics Data System (ADS)

A ferroelectric transition of phenazine (Phz) chloranilic acid (H 2ca) co-crystal was studied by 35Cl nuclear quadrupole resonance (NQR). The single NQR line observed at 36.689 MHz at 295 K, split into a doublet below the ferroelectric transition temperature Tc=253 K in accord with the inversion-symmetry breaking at the H 2ca molecular center in the crystal. The continuous variation of the splitting-width through Tc suggests a second-order nature of this phase transition. The NQR frequency is consistent with the crystal structure in which the two acid hydrogen atoms of H 2ca remain as attached to the quinone molecules. The spin-lattice relaxation time T1 showed a decrease with decreasing temperature in the ferroelectric phase. This suggests the existence of a fast motion of nearby atomic group, which is a cause of electric field gradient fluctuation.

Asaji, Tetsuo; Gotoh, Kazuma; Watanabe, Jun

2006-06-01

34

NMR and NQR Studies on Non-centrosymmetric Superconductors Re7B3, LaBiPt, and BiPd  

NASA Astrophysics Data System (ADS)

We report the nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements for non-centrosymmetric superconductors Re7B3, LaBiPt, and BiPd containing heavy elements. For all three compounds, the spin--lattice relaxation rate 1/T1 shows a coherence peak just below Tc and decreases exponentially at low temperatures, which indicates that an isotropic superconducting gap is dominant in these compounds. In BiPd, the height of the coherence peak just below Tc is much suppressed, which suggests that there exists a substantial component of gap with nodes in this compound. Our results indicate that heavy element is not the only factor, but the extent of inversion symmetry breaking is also important to induce a large spin--orbit coupling and an unconventional superconducting state.

Matano, Kazuaki; Maeda, Satoki; Sawaoka, Hiroki; Muro, Yuji; Takabatake, Toshiro; Joshi, Bhanu; Ramakrishnan, Srinivasan; Kawashima, Kenji; Akimitsu, Jun; Zheng, Guo-qing

2013-08-01

35

Effect of substituents on the /sup 35/Cl NQR frequencies of atoms in conditions of hyperconjugation  

SciTech Connect

The authors studied the mechanisms of the change in the NOR spectra in a series of alpha-chloro-substituted dialkyl ethers, organonitrogen compounds, and benzyl and benzylidene chlorides. The NQR spectra were made on a pulsed IS-3 spectrometer at a temperature of 77 degrees K. There are n-o and ..pi..-o interactions which decrease the Cl 35 and Br 79 NQR frequencies in the series of alpha-chloro ethers, alpha-chloroalkylamides, and benzyl halides. The introduction of a geminal halogen atom (dichloromethyl ethers, benzylidene halides) decreases the effect of hyperconjugation.

Arbuzov, B.A.; Andreeva, A.I.; Bredikhin, A.A.; Safin, I.A.; Vereshchagin, A.N.

1985-12-10

36

A miniaturized NQR spectrometer for a multi-channel NQR-based detection device.  

PubMed

A low frequency (0.5-5 MHz) battery operated sensitive pulsed NQR spectrometer with a transmitter power up to 5 W and a total mass of about 3 kg aimed at detecting (14)N NQR signals, predominantly of illicit materials, was designed and assembled. This spectrometer uses a standard software defined radio (SDR) platform for the data acquisition unit. Signal processing is done with the LabView Virtual instrument on a personal computer. We successfully tested the spectrometer by measuring (14)N NQR signals from aminotetrazole monohydrate (ATMH), potassium nitrate (PN), paracetamol (PCM) and trinitrotoluene (TNT). Such a spectrometer is a feasible component of a portable single or multichannel (14)N NQR based detection device. PMID:25233110

Beguš, Samo; Jazbinšek, Vojko; Pirnat, Janez; Trontelj, Zvonko

2014-10-01

37

Inhibition of the sodium-translocating NADH-ubiquinone oxidoreductase [Na+-NQR] decreases cholera toxin production in Vibrio cholerae O1 at the late exponential growth phase.  

PubMed

Two virulence factors produced by Vibrio cholerae, cholera toxin (CT) and toxin-corregulated pilus (TCP), are indispensable for cholera infection. ToxT is the central regulatory protein involved in activation of CT and TCP expression. We previously reported that lack of a respiration-linked sodium-translocating NADH-ubiquinone oxidoreductase (Na(+)-NQR) significantly increases toxT transcription. In this study, we further characterized this link and found that Na(+)-NQR affects toxT expression only at the early-log growth phase, whereas lack of Na(+)-NQR decreases CT production after the mid-log growth phase. Such decreased CT production was independent of toxT and ctxB transcription. Supplementing a respiratory substrate, l-lactate, into the growth media restored CT production in the nqrA-F mutant, suggesting that decreased CT production in the Na(+)-NQR mutant is dependent on electron transport chain (ETC) activity. This notion was supported by the observations that two chemical inhibitors, a Na(+)-NQR specific inhibitor 2-n-Heptyl-4-hydroxyquinoline N-oxide (HQNO) and a succinate dehydrogenase (SDH) inhibitor, thenoyltrifluoroacetone (TTFA), strongly inhibited CT production in both classical and El Tor biotype strains of V. cholerae. Accordingly, we propose the main respiratory enzyme of V. cholerae, as a potential drug target to treat cholera because human mitochondria do not contain Na(+)-NQR orthologs. PMID:24361395

Minato, Yusuke; Fassio, Sara R; Reddekopp, Rylan L; Häse, Claudia C

2014-01-01

38

Local magnetic and structural properties of the low-temperature orthorhombic to low-temperature tetragonal transition: A {sup 139}La NQR study in lightly hole-doped La{sub 1.8{minus}x}Eu{sub 0.2}Sr{sub x}CuO{sub 4}  

SciTech Connect

{sup 139}La nuclear quadrupole resistance (NQR) and relaxation measurements in lightly hole-doped La{sub 1.8{minus}x}Eu{sub 0.2}Sr{sub x}CuO{sub 4} have been used to investigate the microscopic properties of the low-temperature orthorhombic to low-temperature tetragonal transition. The transition is characterized by a sharp peak in {sup 139}La NQR relaxation rate, indicating phonon softening. We find that the structural phase transition is accompanied by a modification of the spin state. The data for the spin freezing and the recovery of sublattice magnetization at low T are presented and discussed in relation to the studies of La{sub 2{minus}x}Sr{sub x}CuO{sub 4} and La{sub 2}Cu{sub 1{minus}x}Li{sub x}O{sub 4}. {copyright} {ital 1999} {ital The American Physical Society}

Suh, B.J.; Hammel, P.C. [Condensed Matter and Thermal Physics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Condensed Matter and Thermal Physics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Huecker, M.; Buechner, B. [II. Physikalisches Institut, Universitaet zu Koeln, D-50937 Koeln (Germany)] [II. Physikalisches Institut, Universitaet zu Koeln, D-50937 Koeln (Germany)

1999-02-01

39

Local magnetic and structural properties of the low-temperature orthorhombic to low-temperature tetragonal transition: A 139La NQR study in lightly hole-doped La1.8-xEu0.2SrxCuO4  

NASA Astrophysics Data System (ADS)

139La nuclear quadrupole resistance (NQR) and relaxation measurements in lightly hole-doped La1.8-xEu0.2SrxCuO4 have been used to investigate the microscopic properties of the low-temperature orthorhombic to low-temperature tetragonal transition. The transition is characterized by a sharp peak in 139La NQR relaxation rate, indicating phonon softening. We find that the structural phase transition is accompanied by a modification of the spin state. The data for the spin freezing and the recovery of sublattice magnetization at low T are presented and discussed in relation to the studies of La2-xSrxCuO4 and La2Cu1-xLixO4.

Suh, B. J.; Hammel, P. C.; Hücker, M.; Büchner, B.

1999-02-01

40

Roles of the Sodium-Translocating NADH:Quinone Oxidoreductase (Na+-NQR) on Vibrio cholerae Metabolism, Motility and Osmotic Stress Resistance  

PubMed Central

The Na+ translocating NADH:quinone oxidoreductase (Na+-NQR) is a unique respiratory enzyme catalyzing the electron transfer from NADH to quinone coupled with the translocation of sodium ions across the membrane. Typically, Vibrio spp., including Vibrio cholerae, have this enzyme but lack the proton-pumping NADH:ubiquinone oxidoreductase (Complex I). Thus, Na+-NQR should significantly contribute to multiple aspects of V. cholerae physiology; however, no detailed characterization of this aspect has been reported so far. In this study, we broadly investigated the effects of loss of Na+-NQR on V. cholerae physiology by using Phenotype Microarray (Biolog), transcriptome and metabolomics analyses. We found that the V. cholerae ?nqrA-F mutant showed multiple defects in metabolism detected by Phenotype Microarray. Transcriptome analysis revealed that the V. cholerae ?nqrA-F mutant up-regulates 31 genes and down-regulates 55 genes in both early and mid-growth phases. The most up-regulated genes included the cadA and cadB genes, encoding a lysine decarboxylase and a lysine/cadaverine antiporter, respectively. Increased CadAB activity was further suggested by the metabolomics analysis. The down-regulated genes include sialic acid catabolism genes. Metabolomic analysis also suggested increased reductive pathway of TCA cycle and decreased purine metabolism in the V. cholerae ?nqrA-F mutant. Lack of Na+-NQR did not affect any of the Na+ pumping-related phenotypes of V. cholerae suggesting that other secondary Na+ pump(s) can compensate for Na+ pumping activity of Na+-NQR. Overall, our study provides important insights into the contribution of Na+-NQR to V. cholerae physiology. PMID:24811312

Minato, Yusuke; Halang, Petra; Quinn, Matthew J.; Faulkner, Wyatt J.; Aagesen, Alisha M.; Steuber, Julia; Stevens, Jan F.; Häse, Claudia C.

2014-01-01

41

Roles of the sodium-translocating NADH:quinone oxidoreductase (Na+-NQR) on vibrio cholerae metabolism, motility and osmotic stress resistance.  

PubMed

The Na+ translocating NADH:quinone oxidoreductase (Na+-NQR) is a unique respiratory enzyme catalyzing the electron transfer from NADH to quinone coupled with the translocation of sodium ions across the membrane. Typically, Vibrio spp., including Vibrio cholerae, have this enzyme but lack the proton-pumping NADH:ubiquinone oxidoreductase (Complex I). Thus, Na+-NQR should significantly contribute to multiple aspects of V. cholerae physiology; however, no detailed characterization of this aspect has been reported so far. In this study, we broadly investigated the effects of loss of Na+-NQR on V. cholerae physiology by using Phenotype Microarray (Biolog), transcriptome and metabolomics analyses. We found that the V. cholerae ?nqrA-F mutant showed multiple defects in metabolism detected by Phenotype Microarray. Transcriptome analysis revealed that the V. cholerae ?nqrA-F mutant up-regulates 31 genes and down-regulates 55 genes in both early and mid-growth phases. The most up-regulated genes included the cadA and cadB genes, encoding a lysine decarboxylase and a lysine/cadaverine antiporter, respectively. Increased CadAB activity was further suggested by the metabolomics analysis. The down-regulated genes include sialic acid catabolism genes. Metabolomic analysis also suggested increased reductive pathway of TCA cycle and decreased purine metabolism in the V. cholerae ?nqrA-F mutant. Lack of Na+-NQR did not affect any of the Na+ pumping-related phenotypes of V. cholerae suggesting that other secondary Na+ pump(s) can compensate for Na+ pumping activity of Na+-NQR. Overall, our study provides important insights into the contribution of Na+-NQR to V. cholerae physiology. PMID:24811312

Minato, Yusuke; Fassio, Sara R; Kirkwood, Jay S; Halang, Petra; Quinn, Matthew J; Faulkner, Wyatt J; Aagesen, Alisha M; Steuber, Julia; Stevens, Jan F; Häse, Claudia C

2014-01-01

42

35 Cl, 79 Br, 81 Br, and 127 I NQR spectra of organomercury halides  

Microsoft Academic Search

A study of the NQR spectra of some halides disclosed that in the crystals of organomercury halides the behavior of the quadrupole constants is determined to a greater degree by the effect of the nature of the substituants on the intermolecular coordination reactions of Hg... Hal than by the usual transfer of the influence of the electronic effects along the

E. V. Bryukhova; A. K. Prokof'ev; T. Ya. Mel'nikova; O. Yu. Okhlobystia; G. K. Semin

1974-01-01

43

75As, 63Cu NMR and NQR characterization of selected arsenic minerals.  

PubMed

The direct measurement and identification of solid state arsenic phases using (75)As NMR is made difficult by the simultaneous conditions of large quadrupole moment and low coordination symmetry in many compounds. However, specific arsenic minerals can efficiently be detected and discriminated via nuclear quadrupolar resonance (NQR). We report on the first NMR and NQR measurements in the natural minerals enargite (Cu3AsS4), niccolite (NiAs), arsenopyrite (FeAsS) and loellingite (FeAs2). The NQR frequencies have been determined from both high-field NMR powder patterns and via zero-field frequency sweeps. Density functional theory (DFT) based ab initio calculations support the experimental results. The compounds studied here are common in terms of the known set of As-containing minerals. They are sometimes encountered in the context of base metal or gold mining. The study represents a significant addition to the list of arsenic minerals that can now be detected with NQR techniques. PMID:23706610

Lehmann-Horn, J A; Miljak, D G; Bastow, T J

2013-01-01

44

Crystallization and preliminary analysis of the NqrA and NqrC subunits of the Na+-translocating NADH:ubiquinone oxidoreductase from Vibrio cholerae.  

PubMed

The Na+-translocating NADH:ubiquinone oxidoreductase (Na+-NQR) from Vibrio cholerae is a membrane protein complex consisting of six different subunits NqrA-NqrF. The major domains of the NqrA and NqrC subunits were heterologously expressed in Escherichia coli and crystallized. The structure of NqrA1-377 was solved in space groups C222? and P2? by SAD phasing and molecular replacement at 1.9 and 2.1?Å resolution, respectively. NqrC devoid of the transmembrane helix was co-expressed with ApbE to insert the flavin mononucleotide group covalently attached to Thr225. The structure was determined by molecular replacement using apo-NqrC of Parabacteroides distasonis as search model at 1.8?Å resolution. PMID:25005105

Vohl, Georg; Nedielkov, Ruslan; Claussen, Björn; Casutt, Marco S; Vorburger, Thomas; Diederichs, Kay; Möller, Heiko M; Steuber, Julia; Fritz, Günter

2014-07-01

45

127 I and 79 Br NQR spectra of halo-substituted phenols and phenylmercury phenoxides  

Microsoft Academic Search

The full127I NQR spectra of a series of iodo-substituted phenols and phenylmercury phenoxides have been studied. The quadrupole coupling constants and asymmetry parameters have been determined. The character of the OH...Hal hydrogen bond has been found to depend on the nature of substituents in the ring. Correlation dependences of the asymmetry parameters on the sum of the substituents resonance constants

G. K. Semin; S. I. Gushchin; S. B. Karpov; E. V. Bryukhova; L. S. Golovchenko; D. N. Kramov

1996-01-01

46

NQR Characteristics of an RDX Plastic Explosives Simulant.  

PubMed

For reliable detection of explosives, a combination of methods integrated within a single measurement platform may increase detection performance. However, the efficient field testing of such measurement platforms requires the use of inexplosive simulants that are detectable by a wide range of methods. Physical parameters such as simulant density, elemental composition and crystalline structure must closely match those of the target explosive. The highly discriminating bulk detection characteristics of nuclear quadrupole resonance (NQR) especially constrain simulant design. This paper describes the development of an inexplosive RDX simulant suited to a wide range of measurement methods, including NQR. Measurements are presented that confirm an RDX NQR response from the simulant. The potential use of the simulant for field testing a prototype handheld NQR-based RDX detector is analyzed. Only modest changes in prototype operation during field testing would be required to account for the use of simulant rather than real explosive. PMID:23204647

Turecek, J; Schwitter, B; Miljak, D; Stancl, M

2012-12-01

47

Frequency selective detection of nuclear quadrupole resonance (NQR) spin echoes  

NASA Astrophysics Data System (ADS)

Nuclear Quadrupole Resonance (NQR) is a radio frequency (RF) technique that can be used to detect the presence of quadrupolar nuclei, such as the 14N nucleus prevalent in many explosives and narcotics. The technique has been hampered by low signal-to-noise ratios and is further aggravated by the presence of RF interference (RFI). To ensure accurate detection, proposed detectors should exploit the rich form of the NQR signal. Furthermore, the detectors should also be robust to any remaining residual interference, left after suitable RFI mitigation has been employed. In this paper, we propose a new NQR data model, particularly for the realistic case where multiple pulse sequences are used to generate trains of spin echoes. Furthermore, we refine two recently proposed approximative maximum likelihood (AML) detectors, enabling the algorithm to optimally exploit the data model of the entire echo train and also incorporate knowledge of the temperature dependent spin-echo decay time. The AML-based detectors ensure accurate detection and robustness against residual RFI, even when the temperature of the sample is not precisely known, by exploiting the dependencies of the NQR resonant lines on temperature. Further robustness against residual interference is gained as the proposed detector is frequency selective; exploiting only those regions of the spectrum where the NQR signal is expected. Extensive numerical evaluations based on both simulated and measured NQR data indicate that the proposed Frequency selective Echo Train AML (FETAML) detector offers a significant improvement as compared to other existing detectors.

Somasundaram, Samuel D.; Jakobsson, Andreas; Smith, John A. S.; Althoefer, Kaspar A.

2006-05-01

48

Site-directed mutagenesis of conserved cysteine residues in NqrD and NqrE subunits of Na+-translocating NADH:quinone oxidoreductase.  

PubMed

Each of two hydrophobic subunits of Na+-translocating NADH:quinone oxidoreductase (NQR), NqrD and NqrE, contain a pair of strictly conserved cysteine residues within their transmembrane alpha-helices. Site-directed mutagenesis showed that substitutions of these residues in NQR of Vibrio harveyi blocked the Na+-dependent and 2-n-heptyl-4-hydroxyquinoline N-oxide-sensitive quinone reductase activity of the enzyme. However, these mutations did not affect the interaction of NQR with NADH and menadione. It was demonstrated that these conserved cysteine residues are necessary for the correct folding and/or the stability of the NQR complex. Mass and EPR spectroscopy showed that NQR from V. harveyi bears only a 2Fe-2S cluster as a metal-containing prosthetic group. PMID:18298367

Fadeeva, M S; Bertsova, Y V; Verkhovsky, M I; Bogachev, A V

2008-02-01

49

Low-frequency NMR and NQR with a dc SQUID amplifier  

SciTech Connect

A sensitive Fourier-transform spectrometer based on a dc SQUID (Superconducting QUantum Interference Device) has been developed for the direct detection of nuclear magnetic resonance (NMR) in zero applied magnetic field and pure nuclear quadrupole resonance (NQR) at low frequencies. The motivation to detect zero field NMR and NQR is to provide a new high resolution spectroscopy technique at frequencies below 200 kHz to study ultra-weak interactions in chemicals and materials. By comparing the sensitivity of a SQUID amplifier with that of a conventional semiconductor amplifier, it is shown that a SQUID amplifier is essential for the direct detection of low frequency resonant signals. The spectrometer has a frequency response extending from about 10 to 200 kHz, and a recovery time (after the magnetic pulse is removed) of about 50 {mu}s. The spectrometer is used to detect NMR spectra from Pt and Cu metal powders in a magnetic field of 6 mtesla, and NQR spectra from {sup 2}D in a tunneling methyl group and {sup 14}N in NH{sub 4}ClO{sub 4}. Finally, the zero field NMR spectrum from a quantum tunneling methyl group is calculated. 25 refs., 34 figs., 2 tabs.

Fan, Nong-Qiang.

1990-11-01

50

A Mutation in Na(+)-NQR Uncouples Electron Flow from Na(+) Translocation in the Presence of K(+).  

PubMed

The sodium-pumping NADH:ubiquinone oxidoreductase (Na(+)-NQR) is a bacterial respiratory enzyme that obtains energy from the redox reaction between NADH and ubiquinone and uses this energy to create an electrochemical Na(+) gradient across the cell membrane. A number of acidic residues in transmembrane helices have been shown to be important for Na(+) translocation. One of these, Asp-397 in the NqrB subunit, is a key residue for Na(+) uptake and binding. In this study, we show that when this residue is replaced with asparagine, the enzyme acquires a new sensitivity to K(+); in the mutant, K(+) both activates the redox reaction and uncouples it from the ion translocation reaction. In the wild-type enzyme, Na(+) (or Li(+)) accelerates turnover while K(+) alone does not activate. In the NqrB-D397N mutant, K(+) accelerates the same internal electron transfer step (2Fe-2S ? FMNC) that is accelerated by Na(+). This is the same step that is inhibited in mutants in which Na(+) uptake is blocked. NqrB-D397N is able to translocate Na(+) and Li(+), but when K(+) is introduced, no ion translocation is observed, regardless of whether Na(+) or Li(+) is present. Thus, this mutant, when it turns over in the presence of K(+), is the first, and currently the only, example of an uncoupled Na(+)-NQR. The fact the redox reaction and ion pumping become decoupled from each other only in the presence of K(+) provides a switch that promises to be a useful experimental tool. PMID:25486106

Shea, Michael E; Mezic, Katherine G; Juárez, Oscar; Barquera, Blanca

2015-01-20

51

Two-dimensional NQR using ultra-broadband electronics.  

PubMed

We have recently developed an ultra-broadband instrument that can effectively excite and detect NMR and NQR signals over a wide frequency range. Our current system operates between 100 kHz and 3.2 MHz using an un-tuned sample coil. The major benefits of this instrument compared to conventional NQR/NMR systems include increased robustness, ease of use (in particular for multi-frequency experiments), and elimination of the need for tuning adjustments in the hardware. Here we describe its use for performing two-dimensional (2D) scans, which allow improved interpretation of complex NQR spectra by detecting the connected resonances. Our method relies on population transfers between the three energy levels of spin-1 nuclei (such as (14)N) by using multi-frequency excitation and a single RF coil. Experimental results on pure samples and mixtures are also presented. PMID:24495675

Mandal, S; Song, Y-Q

2014-03-01

52

Rapid detection of arsenic minerals using portable broadband NQR  

NASA Astrophysics Data System (ADS)

remote real-time detection of specific arsenic species would significantly benefit in minerals processing to mitigate the release of arsenic into aquatic environments and aid in selective mining. At present, there are no technologies available to detect arsenic minerals in bulk volumes outside of laboratories. Here we report on the first room-temperature broadband 75As nuclear quadrupole resonance (NQR) detection of common and abundant arsenic ores in the Earth crust using a large sample (0.78 L) volume prototype sensor. Broadband excitation aids in detection of natural minerals with low crystallinity. We briefly discuss how the proposed NQR detector could be employed in mining operations.

Lehmann-Horn, J. A.; Miljak, D. G.; O'Dell, L. A.; Yong, R.; Bastow, T. J.

2014-10-01

53

Interplane coupling in the superconductor Y2Ba4Cu7O15 as revealed by NQR spin-echo double resonance  

NASA Astrophysics Data System (ADS)

We report a detailed spin-echo double-resonance study of the planar Cu sites in Y2Ba4Cu7O15 above Tc employing nuclear quadrupole resonance (NQR). The experiments directly reveal the coupling between the inequivalent single planes of a double CuO2 plane. The ratio of particular NQR relaxation rates is a measure for the strength of this interplane coupling with respect to the intraplane coupling. This ratio increases with decreasing temperature. Using recent calculations by Millis and Monien, an interplane coupling constant of about 5 meV is deduced.

Stern, R.; Mali, M.; Roos, J.; Brinkmann, D.

1995-12-01

54

Ultra-Low Temperature Thermometry Using Zeeman Perturbed NQR  

Microsoft Academic Search

We report the results of measurements of the magnetic field perturbed nuclear quadrupole resonance (NQR) lines of powdered Sb immersed in liquid3He at low temperatures. The magnetic field was used to separate the frequencies of the allowed transitions between the \\u000a

E. B. Genio; G. G. Ihas; N. S. Sullivan

1998-01-01

55

I: Low Frequency NMR and NQR Using a dc SQUID. II: Variable-temperature 13C CP\\/MAS of Organometallics  

Microsoft Academic Search

NMR and NQR at low frequencies are difficult prospects due to small nuclear spin polarization. Furthermore, the sensitivity'of the inductive pickup circuitry of standard spectrometers is reduced as the frequency is lowered. I have used a cw-SQUID (Superconducting QUantum Interference Device) spectrometer, which has no such frequency dependence, to study the local atomic environment of ¹N via the quadrupolar interaction.

Ziegeweid

1995-01-01

56

Possibility of valence-fluctuatsion-mediated superconductivity in Cd-doped CeIrIn(5) probed by In NQR.  

PubMed

We report on a pressure-induced evolution of exotic superconductivity and spin correlations in CeIr(In(1-x)Cd(x))(5) by means of in-nuclear-quadrupole-resonance (NQR) studies. Measurements of an NQR spectrum and nuclear-spin-lattice-relaxation rate 1/T(1) have revealed that antiferromagnetism induced by Cd doping emerges locally around Cd dopants, but superconductivity is suddenly induced at T(c)=0.7 and 0.9 K at 2.34 and 2.75 GPa, respectively. The unique superconducting characteristics with a large fraction of the residual density of state at the Fermi level which increases with T(c) differ from those for anisotropic superconductivity mediated by antiferromagnetic correlations. By incorporating the pressure dependence of the NQR frequency pointing to the valence change of Ce, we suggest that unconventional superconductivity in the CeIr(In(1-x)Cd(x))(5) system may be mediated by valence fluctuations. PMID:23005666

Yashima, M; Tagami, N; Taniguchi, S; Unemori, T; Uematsu, K; Mukuda, H; Kitaoka, Y; Ota, Y; Honda, F; Settai, R; Onuki, Y

2012-09-14

57

14N NQR and relaxation in ammonium nitrate  

NASA Astrophysics Data System (ADS)

The complete 14N nuclear quadrupole resonance (NQR) spectrum of ammonium nitrate is presented recorded using two double resonance techniques - double contact cross relaxation and zero field NQR. The spectra gave the quadrupole coupling constant (Qcc) and asymmetry parameter (?) values for the nitro of 611 kHz, 0.229 and that for the ammonium nitrogen of 242 kHz, 0.835. The three relaxation transition probabilities have been determined for both the nitro and ammonium nitrogen atoms. The bi-exponential relaxation times (T 1) were measured at 295 K. The values for nitro are 16.9 s and 10.5 s and that of the ammonium are 23.0 s and 16.4 s.

Stephenson, David

2014-11-01

58

Infrared spectroscopic evidence of a redox-dependent conformational change involving ion binding residue NqrB-D397 in the Na(+)-pumping NADH:quinone oxidoreductase from Vibrio cholerae.  

PubMed

The Na(+)-pumping NADH:quinone oxidoreductase (Na(+)-NQR) is a unique respiratory enzyme that conserves energy by translocating Na(+) through the plasma membrane. Found only in prokaryotes, the enzyme serves as the point of entry of electrons into the respiratory chain in many pathogens, including Vibrio cholerae and Yersinia pestis. In this study, a combined electrochemical and Fourier transform infrared (FTIR) spectroscopic approach revealed that Na(+)-NQR undergoes significant conformational changes upon oxidoreduction, depending on the monovalent cation present (Na(+), Li(+), K(+), or Rb(+)). In the presence of the inhibitor Rb(+), additional conformational changes are evident, indicating a changed accessibility of the sodium binding sites. In electrochemically induced FTIR difference spectra, the involvement of deprotonated acid residues in the binding of cations, together with the spectral features, that point toward a monodentate binding mode for these acid residues in the oxidized form of the enzyme and bidentate binding in the reduced form could be identified. The measurements confirmed that NqrB-D397 is one of the acid residues involved in Na(+) and Li(+) binding. In the NqrB-D397E mutant, the spectral features characteristic of COO(-) groups are shifted, and a weakening of the hydrogen binding of the ion binding cluster is revealed. Finally, H-D exchange kinetics of amide protons confirmed that Na(+)-NQR adopts different conformations, with different accessibilities to the aqueous environment, depending on the cation present, which contributes to the selectivity mechanism of ion translocation. PMID:23566241

Neehaul, Yashvin; Juárez, Oscar; Barquera, Blanca; Hellwig, Petra

2013-05-01

59

35 Cl, 79 Br, and 127 I NQR spectra of some halogen-containing organoselenium compounds  

Microsoft Academic Search

1.The35Cl,79Br, and127I NQR spectra of a number of halogen-containing organoselenium compounds were obtained.2.The35Cl NQR frequencies of compounds of type R1R2R3SeCl (Ri=Me, Ph, Cl) are linearly related to the induction constants of the substituentssi.

V. V. Saatsazov; T. L. Khotsyanova; N. N. Magdesieva; S. I. Kuznetsov; I. M. Alymov; R. A. Kyandzhetsian; E. V. Bryukhova

1974-01-01

60

35 Cl, 79 Br, and 127 I NQR spectra of several polyhalophenols and their phenylmercury derivatives  

Microsoft Academic Search

1.The intramolecular contribution to the splitting of the NQR frequencies in the 2,6-dihalo-4-X-derivatives of phenol has been separated out. The strength of the intramolecular hydrogen bond is substantially dependent on the nature of the substituants in position 4. The splittings in the NQR spectra are reduced upon passing from electron-accepting substituents to electron-donating substituents.2.The intramolecular coordination interactions of mercury atoms

G. Ko Semin; E. V. Bryukhova; D. N. Kravtsov; L. S. Golovchenko

1982-01-01

61

NMR and NQR investigations of local symmetry in the hidden order phase of URu2Si2  

NASA Astrophysics Data System (ADS)

In order to study local symmetries at the 4e(Si)- and 4d(Ru)-sites above and below hidden order transition temperature TO = 17.5 K in URu2Si2, we have investigated the nuclear quadrupole interaction by 73Ge-nuclear magnetic resonance (NMR) measurement on a 10% 73Ge-substituted sample URu2(Si0.9Ge0.1)2, and by 101Ru-nuclear quadrupole resonance (NQR) measurement on a pure single crystal sample. The present 73Ge-NMR measurements do not give any evidence for change in the local symmetry at 4e-site within experimental accuracy. On the other hand, the precise measurement of 101Ru-NQR frequency has detected an anomaly just below TO as sensitively as the thermal expansion measurement dose. Its temperature dependence shows a linear relation with that of the in-plane lattice parameter, which may be a clue to clarify a modification in microscopic charge distribution at TO.

Mito, T.; Hattori, M.; Motoyama, G.; Sakai, Y.; Koyama, T.; Ueda, K.; Kohara, T.; Yokoyama, M.; Amitsuka, H.

2012-12-01

62

NMR/NQR and disorder effects in URu2Si2  

NASA Astrophysics Data System (ADS)

NMR experiments at ambient pressure in URu2Si2 demonstrate a linewidth enhancement effect at the hidden order transition temperature (T0). We find that larger amounts of sample disorder appear to induce larger linewidth enhancement at T0. We will present recent NMR and NQR experiments in oriented powder and single crystal samples of URu2Si2 and discuss the measurements with emphasis on a possible connection between linewidth/disorder effects and hidden order. Both NQR and NMR spectra as functions of temperature and NMR for different magnetic field strengths and orientations will be reported.

Bernal, O. O.; Ishida, K.; Reyes, A. P.; Maclaughlin, D. E.; Lukefarh, H. G.; Mydosh, J. A.; Gortenmulder, T. J.; Amitsuka, H.

2005-03-01

63

Nuclear quadrupole resonance study of hydrogen bonded solid materials.  

PubMed

Nuclear quadrupole resonance is presented as a method for the study of solid hydrogen bonded materials. NQR study of hydrogen bonds in ferroelectric and paraelectric KH2PO4, antiferroelectric and paraelectric squaric acid, ferroelectric croconic acid and antiferroelectric and paraelectric cocrystal 5'-dimethyl-2, 2'-bipyridine - chloranilic acid (1:1) are discussed in more details. A 14N NQR study of the strong short O-HKN hydrogen bond in two polymorphic forms of cocrystal isonicotinamide-oxalic acid (2:1) is presented as well. Various correlations between the NQR parameters and between the NQR and structural parameters have been observed. These correlations may be used to determine the proton position in a hydrogen bond and some other structural parameters from the NQR data. PMID:24062106

Seliger, Janez

2011-09-01

64

IMPLEMENTATION OF A -NQR SYSTEM AT THE NSCL FOR GROUND STATE QUADRUPOLE MOMENT  

E-print Network

The nuclear electric quadrupole moment, Q, is a direct measure of the nuclear charge distribution, and provides an important test of nuclear structure models. The detected nuclear quadrupole resonance (-NQR, my family, all my teachers and friends iii #12;ACKNOWLEDGMENTS I am very grateful to my advisor

Mantica, Paul F.

65

The conformational changes induced by ubiquinone binding in the Na+-pumping NADH:ubiquinone oxidoreductase (Na+-NQR) are kinetically controlled by conserved glycines 140 and 141 of the NqrB subunit.  

PubMed

Na(+)-pumping NADH:ubiquinone oxidoreductase (Na(+)-NQR) is responsible for maintaining a sodium gradient across the inner bacterial membrane. This respiratory enzyme, which couples sodium pumping to the electron transfer between NADH and ubiquinone, is not present in eukaryotes and as such could be a target for antibiotics. In this paper it is shown that the site of ubiquinone reduction is conformationally coupled to the NqrB subunit, which also hosts the final cofactor in the electron transport chain, riboflavin. Previous work showed that mutations in conserved NqrB glycine residues 140 and 141 affect ubiquinone reduction and the proper functioning of the sodium pump. Surprisingly, these mutants did not affect the dissociation constant of ubiquinone or its analog HQNO (2-n-heptyl-4-hydroxyquinoline N-oxide) from Na(+)-NQR, which indicates that these residues do not participate directly in the ubiquinone binding site but probably control its accessibility. Indeed, redox-induced difference spectroscopy showed that these mutations prevented the conformational change involved in ubiquinone binding but did not modify the signals corresponding to bound ubiquinone. Moreover, data are presented that demonstrate the NqrA subunit is able to bind ubiquinone but with a low non-catalytically relevant affinity. It is also suggested that Na(+)-NQR contains a single catalytic ubiquinone binding site and a second site that can bind ubiquinone but is not active. PMID:25006248

Strickland, Madeleine; Juárez, Oscar; Neehaul, Yashvin; Cook, Darcie A; Barquera, Blanca; Hellwig, Petra

2014-08-22

66

35 Cl, 79 Br, and 127 I NQR spectra and crystallographic parameters of some halomethylated phosphine oxides  

Microsoft Academic Search

1.The35Cl,79Br, and127I NQR spectra and the crystallographic parameters of a number of halomethylated phosphine oxides were measured.2.A structural nonequivalence of the bromine atoms was detected in (CH2Br)3PO.3.Phase transitions, with a change in the multipleticity of the NQR spectra, were recorded in (CH2Cl)3PO and (CH2I)3PO in the range 77–296°K.

V. V. Saatsazov; T. L. Khotsyanova; S. I. Kuznetsov

1975-01-01

67

DTA and NQR studies of polymorphism in p-chlorofluorobenzene  

Microsoft Academic Search

Differential thermal analysis, and the 35Cl Nuclear Quadrupole Resonance frequency (?Q) and spin-lattice relaxation time (T1) were measured as a function of temperature in p-chlorofluorobenzene. Three different phases were found according to the thermal history of the sample and only one was stable up to the melting point. In one of the phases, the presence of molecular reorientations can be

L. Cerioni; S. Perez; A. Wolfenson

2004-01-01

68

Isomorphism and disorder in o-chlorohalobenzenes studied by NQR.  

PubMed

In this work we present experimental results that allow to characterize different solid modifications found in o-chlorohalobenzenes. Three disordered phases have been found in o-chlorobromobenzene. The stable phase at high temperature (phase I) is also obtained by quenching the sample at 77 K. Slow cooling allow to obtain the low temperature phase III which, on heating, transforms to phase II at 183 K and this, in turns, transforms to phase I at T~210 K. The disorder evidenced through the Nuclear Quadrupole Resonance spectra, is attributed to a random occupation of chlorine and bromine sites. In all phases there is evidence of molecular reorientations out of the benzene ring plane around the pseudo-symmetry axis between the atoms of Cl and Br. In o-chlorofluorobenzene two phases have been found depending on the cooling rate. One phase is disordered due to the random exchange of the occupation of Cl and F sites. In this case, there is also evidence of molecular reorientations out of the benzene ring plane, but in this case the reorientation is around the pseudo-symmetry axis that pass through the C-Cl bonds. Comparisons with the behavior of o-dichlorobenzene are also made. PMID:24440588

Pérez, Silvina C; Wolfenson, Alberto; Zuriaga, Mariano

2014-01-01

69

Copper NQR and NMR in the superconductor YBa2Cu4O8+x  

Microsoft Academic Search

The frequencies nuQ, the linewidth and the spin-lattice and spin-spin relaxation times T1 and T2, respectively, of the 63Cu nuclear quadrupole resonance (NQR) signals for chain and planar copper sites in YBa2Cu4O8 were measured between 6 and 750 K; in addition nuclear magnetic resonance (NMR) spectra were taken at 150 and 300 K. The results are compared with data known

H. Zimmermann; M. Mali; D. Brinkmann; J. Karpinski; E. Kaldis; S. Rusiecki

1989-01-01

70

Some features of double-resonance detection of 17O NQR in ice  

NASA Astrophysics Data System (ADS)

Proton oxygen-17 double resonance was used to detect the NQR signals of 17O in natural abundance and isotope-enriched ice. When a nonmodulated rf irradiation was applied to a search for the NQR signals, absorptions due to the "solid state effect" which were shifted toward higher frequencies from resonance were detected only in enriched samples. In such circumtances, a saturation phenomenon was observed; at a given frequency (in the vicinity of a resonance) and 17O concentration, the scaling-down factor of the proton signal reaches a characteristic minimum value. The dependence of this value on the 17O concentration indicates that the two spin systems evolve toward a common final spin temperature in the rotating frame, limiting the signal detection to enriched ice. When the NQR irradiation was modulated at a frequency comparable to the dipole-dipole interaction energy between the two nuclear spin systems and applied at resonance, the proton spin temperature evolved to infinity, thus allowing signal detection even at very low concentrations such as the natural abundance of 17O. Distinct signals were detected at 1615 ± 5, 1710 ± 5, and 3320 ± 10 kHz, which yield the quadrupolar parameters e2qQ = 6.42 MHz and ? = 0.924, consistent with a recent report by Brosnon and Edmonds.

Margalit, Yair; Shporer, Mordechai

71

Correlation between proton transfer and (35)Cl NQR frequency as well as molecular geometry of chloranilic acid in co-crystals with some organic bases.  

PubMed

Proton transfer in hydrogen-bonded organic co-crystals of chloranilic acid with some organic bases was investigated by nuclear quadrupole resonance (NQR) spectroscopy. The (35)Cl NQR frequencies of chloranilic acid molecule as well as (14)N NQR frequencies of the organic base molecule were measured with the conventional pulse methods as well as double-resonance methods, respectively. The extent of proton transfer in the O...H...N hydrogen bond was estimated from Townes-Dailey analysis of the (14)N NQR parameters. The (35)Cl NQR frequency and molecular geometry of chloranilic acid are correlated to the extent of proton transfer in the protonation process of the organic base molecule. It is shown that the hydrogen bond affects the pi-electron system of chloranilic acid. Geometry dependence of the O...H...N hydrogen bond, i.e. the H-N valence bond order versus the hydrogen-bond geometry correlation is also discussed. PMID:20535777

Asaji, Tetsuo; Seliger, Janez; Zagar, Veselko; Ishida, Hiroyuki

2010-07-01

72

Electronic properties of Y-Ba-Cu-O superconductors as seen by Cu and O NMR/NQR  

SciTech Connect

Nuclear Magnetic Resonance (NMR) and Nuclear Quadrupole Resonance (NQR) allow the investigation of electronic properties at the atomic level. The authors will report on such studies of typical members of the the Y-Ba-Cu-O family such as YBa2Cu30(6 + x) (1-2-3-(6 + x)), YBa2Cu4O8 (1-2-4) and Y2Ba4Cu7015 (2-4-7) with many examples of recent work performed in their laboratory. In particular, they will deal with Knight shift and relaxation studies of copper and oxygen. They will discuss important issues of current studies such as: (1) Existence of a common electronic spin-susceptibility in the planes (and perhaps in the chains) of 1-2-4; (2) Strong evidence for the existence of a pseudo spin-gap of the antiferromagnetic fluctuations in 1-2-4 and 2-4-7; (3) Evidence for d-wave pairing in 1-2-4; (4) Strong coupling of inequivalent Cu-O planes in 2-4-7 and possible origin for the high Tc value of this compound; and (5) The possibility to describe NMR data in the framework of a charge-excitation picture.

Brinkmann, D.

1995-04-01

73

Electronic properties of Y-Ba-Cu-O superconductors as seen by Cu and O NMR/NQR  

NASA Astrophysics Data System (ADS)

Nuclear Magnetic Resonance (NMR) and Nuclear Quadrupole Resonance (NQR) allow the investigation of electronic properties at the atomic level. We will report on such studies of typical members of the the Y-Ba-Cu-O family such as YBa2Cu30(6 + x) (1-2-3-(6 + x)), YBa2Cu4O8 (1-2-4) and Y2Ba4Cu7015 (2-4-7) with many examples of recent work performed in our laboratory. In particular, we will deal with Knight shift and relaxation studies of copper and oxygen. We will discuss important issues of current studies such as: (1) Existence of a common electronic spin-susceptibility in the planes (and perhaps in the chains) of 1-2-4; (2) Strong evidence for the existence of a pseudo spin-gap of the antiferromagnetic fluctuations in 1-2-4 and 2-4-7; (3) Evidence for d-wave pairing in 1-2-4; (4) Strong coupling of inequivalent Cu-O planes in 2-4-7 and possible origin for the high Tc value of this compound; and (5) The possibility to describe NMR data in the framework of a charge-excitation picture.

Brinkmann, D.

1995-04-01

74

Electronic properties of Y-Ba-Cu-O superconductors as seen by Cu and O NMR/NQR  

NASA Technical Reports Server (NTRS)

Nuclear Magnetic Resonance (NMR) and Nuclear Quadrupole Resonance (NQR) allow the investigation of electronic properties at the atomic level. We will report on such studies of typical members of the the Y-Ba-Cu-O family such as YBa2Cu30(6 + x) (1-2-3-(6 + x)), YBa2Cu4O8 (1-2-4) and Y2Ba4Cu7015 (2-4-7) with many examples of recent work performed in our laboratory. In particular, we will deal with Knight shift and relaxation studies of copper and oxygen. We will discuss important issues of current studies such as: (1) Existence of a common electronic spin-susceptibility in the planes (and perhaps in the chains) of 1-2-4; (2) Strong evidence for the existence of a pseudo spin-gap of the antiferromagnetic fluctuations in 1-2-4 and 2-4-7; (3) Evidence for d-wave pairing in 1-2-4; (4) Strong coupling of inequivalent Cu-O planes in 2-4-7 and possible origin for the high Tc value of this compound; and (5) The possibility to describe NMR data in the framework of a charge-excitation picture.

Brinkmann, D.

1995-01-01

75

Selective excitation of single and multiple quantum transitions for spin 7/2 in NQR  

NASA Astrophysics Data System (ADS)

The dynamics of spin 7/2 in pure NQR is considered. The orientation of the applied RF field is assumed arbitrary and ? ? 0. For this situation various selective pulses are considered and analytical results obtained. Shaped pulses are also treated. A key feature of this work is to construct the interaction representation from which an analytical calculation, using the computer program 'Maple', can be obtained in a tractable form. The results presented are general for all half integer spins of magnitude higher than 1/2.

Ageev, S. Z.; Sanctuary, B. C.

76

Isotope ratio of Cl NQR spin-lattice relaxation times in 1D hydrogen-bonding system of tetramethylpyrazine-chloranilic acid at high temperatures  

NASA Astrophysics Data System (ADS)

The temperature dependences of spin-lattice relaxation time T 1 of 35Cl and 37Cl NQR were studied for the co-crystal of tetramethylpyrazine (TMP) with chloranilic acid (H2ca), TMP-H2ca, in which one-dimensional hydrogen bonding is formed by alternate arrangement of TMP and H2ca. The isotope ratio 37Cl T 1 / 35Cl T 1 was determined to be 1.0 ± 0.1 above ca. 290 K where a steep decrease of spin-lattice relaxation time T 1 with increasing temperature was observed. In this temperature range it is suggested that the relaxation is originated from the slow fluctuation of electric field gradient (EFG). Beside EFG fluctuation due to the external-charge-density fluctuation, the small angle reorientation of the quantization axis triggered by a proton transfer motion between N...H-O and N-H...O hydrogen bonding states is proposed.

Asaji, Tetsuo

2013-05-01

77

Effects of nonsinusoidal character of atomic modulation on NQR spin-lattice relaxation time of incommensurate phases  

Microsoft Academic Search

The present work is an extention of the theoretical calculation developed by Blinc to explain the temperature and frequency dependence of the spin-lattice relaxation time in incommensurate phases. We have evaluated the influence of the nonsinusoidal character of the atomic modulation, in the linear approximation, over the NQR spectra and over the spin-lattice relaxation due to direct and Raman processes.

Silvina C. Pérez; Clemar Schurrer; Alberto Wolfenson

2001-01-01

78

Measurement of in-situ stress in salt and rock using NQR techniques  

SciTech Connect

A discussion of how stress and strain affect the quantities which can be measured in an NQR experiment shows that, for stresses of the magnitude to be expected at depths up to about 10,000 feet, quadrupole coupling constants will fall in the range of 1 to 10 kHz for both the sodium and chloride ions in NaCl. The most promising system involves pulsed nuclear double resonance detection; and alterative is to observe the quadrupolar splitting of the NMR signal. Choices to be made in the measurement and mapping techniques are discussed. The well-known perturbation of the homogenous stress field in the neighborhood of a borehole is shown to be advantageous from the point of view of obtaining directional information on the stress. Construction and operation of a borehole stress sensor are considered. The NQR technique seems feasible for measuring the magnitude and direction of underground stress with a resolution of about 25 psi, or 2.5% at 1000 psi. Downhole instrumentation suitable for in-situ determinations of stress appears within the state of the art. Additional tasks required on the project are identified.

Schempp, E.; Hirschfeld, T.; Klainer, S.

1980-12-01

79

An analytical method for estimating the {sup 14}N nuclear quadrupole resonance parameters of organic compounds with complex free induction decays for radiation effects studies  

SciTech Connect

The use of {sup 14}N nuclear quadrupole resonance (NQR) as a radiation dosimetry tool has only recently been explored. An analytical method for analyzing {sup 14}N NQR complex free induction decays is presented with the background necessary to conduct pulsed NQR experiments. The {sup 14}N NQR energy levels and possible transitions are derived in step-by-step detail. The components of a pulsed NQR spectrometer are discussed along with the experimental techniques for conducting radiation effects experiments using the spectrometer. Three data analysis techniques -- the power spectral density Fourier transform, state space singular value decomposition (HSVD), and nonlinear curve fitting (using the downhill simplex method of global optimization and the Levenberg-Marquart method) -- are explained. These three techniques are integrated into an analytical method which uses these numerical techniques in this order to determine the physical NQR parameters. Sample data sets of urea and guanidine sulfate data are used to demonstrate how these methods can be employed to analyze both simple and complex free induction decays. By determining baseline values for biologically significant organics, radiation effects on the NQR parameters can be studied to provide a link between current radiation dosimetry techniques and the biological effects of radiation.

Iselin, L.H.

1992-12-31

80

Effects of nonsinusoidal character of atomic modulation on NQR spin-lattice relaxation time of incommensurate phases  

SciTech Connect

The present work is an extention of the theoretical calculation developed by Blinc to explain the temperature and frequency dependence of the spin-lattice relaxation time in incommensurate phases. We have evaluated the influence of the nonsinusoidal character of the atomic modulation, in the linear approximation, over the NQR spectra and over the spin-lattice relaxation due to direct and Raman processes. It is shown that the peak with lower intensity in the NQR spectra always has a larger T{sub 1} and viceversa. The results have been applied to bis(4-chlorophenyl)sulfone T{sub 1} and line-shape data. The temperature and frequency dependence of T{sub 1} are well reproduced if Raman processes are considered.

Perez, Silvina C.; Schurrer, Clemar; Wolfenson, Alberto

2001-06-01

81

Detection of {sup 14}N and {sup 35}Cl in cocaine base and hydrochloride using NQR, NMR, and SQUID techniques  

SciTech Connect

Results from {sup 14}N pure NQR of cocaine in the free base form (cocaine base) yield a nuclear quadrupole coupling constant (NQCC) e{sup 2}Qq/h of 5.0229 ({+-}0.0001) MHz and an asymmetry parameter {eta} of 0.0395 ({+-}0.0001) at 295 K, with corresponding values of 5.0460 ({+-}0.0013) MHz and 0.0353 ({+-}0.0008) at 77 K. Both pure NQR (at 295-77 K) and a superconducting quantum interference device (SQUID) detector (at 4.2 K) were used to measure the very low (<1 MHz) {sup 14}N transition frequencies in cocaine hydrochloride; at 295 K the NQCC is 1.1780 ({+-}0.0014) MHz and the asymmetry parameter is 0.2632 ({+-}0.0034). Stepping the carrier frequency enables one to obtain a powder pattern without the severe intensity distortions that otherwise arise from finite pulse power. A powder pattern simulation using an NQCC value of 5.027 MHz and an asymmetry parameter {eta} of 0.2 agrees reasonably well with the experimental stepped-frequency spectrum. The use of pure NQR for providing nondestructive, quantitative, and highly specific detection of crystalline compounds is discussed, as are experimental strategies. 31 refs., 8 figs., 1 tab.

Yesinowski, J.P.; Buess, M.L.; Garroway, A.N. [Naval Research Lab., Washington, DC (United States); Ziegeweid, M.; Pines, A. [Univ. of California, Berkeley, CA (United States)]|[Lawrence Berkeley Lab., CA (United States)

1995-07-01

82

I: Low Frequency NMR and NQR Using a dc SQUID. II: Variable-temperature 13C CP/MAS of Organometallics  

SciTech Connect

NMR and NQR at low frequencies are difficult prospects due to small nuclear spin polarization. Furthermore, the sensitivity'of the inductive pickup circuitry of standard spectrometers is reduced as the frequency is lowered. I have used a cw-SQUID (Superconducting QUantum Interference Device) spectrometer, which has no such frequency dependence, to study the local atomic environment of {sup 14}N via the quadrupolar interaction. Because {sup 14}N has spin I = 1 and a 0-6 MHz frequency range, it is not possible to obtain well-resolved spectra in high magnetic fields. I have used a technique to observe {sup 14}N NQR resonances via their effect on neighboring protons mediated by the heteronuclear dipolar interaction to study peptides and narcotics. The sensitivity of the SQUID is not enough to measure low-frequency surface (or other low spin density) systems. The application of spin-polarized xenon has been previously used to enhance polarization in conventional NMR experiments. Because xenon only polarizes spins with which it is in contact, it is surface selective. While differences in chemical shifts between surface and bulk spins are not large, it is expected that the differences in quadrupole coupling constant should be very large due to the drastic change of the electric field gradient surrounding spins at the surface. With this in mind, I have taken preliminary steps to measure SQUID detected polarization transfer from Xe to another spin species at 4.2 K and in small magnetic fields (<50 G). In this regime, the spin-lattice relaxation of xenon is dependent on the applied magnetic field. The results of our efforts to characterize the relaxation of xenon are presented. The final section describes the solid-state variable-temperature (VT) one- and two-dimensional {sup 13}C cross polarization (CP)/magic angle spinning (MAS) NMR of Hf({eta}{sup 5}-C{sub 5}H{sub 5}){sub 2}({eta}{sup 1}-C{sub 5}H{sub 5}){sub 2}, Zr({eta}{sup 5}-C{sub 5}H{sub 5}){sub 3}({eta}{sup 1}-C{sub 5}H{sub 5}) and Sn({eta}{sup 1}-C{sub 5}H{sub 5}){sub 4}. This work was undertaken in the hope of gaining insight into the intramolecuhrr dynamics, specifically which fluxional processes exist in the solid state, by what mechanism rearrangements are occurring, and the activation energies by which these processes are governed.

Ziegeweid, M.A.

1995-11-29

83

The 14N NQR spectrum and the crystal structure of Ba[Fe(CN) 5NO] · 3H 2O at room temperature  

NASA Astrophysics Data System (ADS)

The previously reported 14N NQR spectrum of the CN groups of Ba [Fe (CN) 5NO] · 3H 2O (BNP) was shown to also contain lines of Na 2 [Fe (CN) 5NO] · 2H 2O used in the preparation of BNP. The number of NQR lines and their relative intensities in BNP confirmed that it has a Pbcm instead of a Pca2 1 space group at 293 K as previously assumed. The three CN sites found in BNP at room temperature are increased to five below 233 K and to eight below 131 K as a result of phase transitions. The effect on the NQR lines of the axial CN group of the disorder of some water molecules in BNP is also discussed.

Murgich, Juan; Bonalde, Ismardo

1990-07-01

84

Detection of ¹⁴N and ³⁵Cl in cocaine base and hydrochloride using NQR, NMR, and SQUID techniques  

Microsoft Academic Search

Results from ¹⁴N pure NQR of cocaine in the free base form (cocaine base) yield a nuclear quadrupole coupling constant (NQCC) e²Qq\\/h of 5.0229 ({+-}0.0001) MHz and an asymmetry parameter η of 0.0395 ({+-}0.0001) at 295 K, with corresponding values of 5.0460 ({+-}0.0013) MHz and 0.0353 ({+-}0.0008) at 77 K. Both pure NQR (at 295-77 K) and a superconducting quantum

James P. Yesinowski; Michael L. Buess; Allen N. Garroway; Marcia. Ziegeweid; Alexander. Pines

1995-01-01

85

New aspects on URu2Si2 and CeT In5 (T=Rh, Ir, Co) observed by high pressure NMR and NQR  

NASA Astrophysics Data System (ADS)

NMR and NQR studies on two interesting systems (URu2Si2, CeTIn5) were performed under high pressure. (1) URu2Si2: In the pressure range 3.0 to 8.3 kbar, we have observed new 29Si NMR signals arising from the antiferromagnetic (AF) region besides the previously observed 29Si NMR signals which come from the paramagnetic (PM) region in the sample. This gives definite evidence for spatially-inhomogeneous development of AF ordering below T0 of 17.5 K. The volume fraction is enhanced by applied pressure, whereas the value of internal field (~ 91 mT) remains constant up to 8.3 kbar. In the AF region, the ordered moment is about one order of magnitude larger than 0.03 mB. (2) CeTIn5: The pressure and temperature (T) dependences of nuclear spin-lattice relaxation rate 1/T1 of 115In in CeTIn5 have shown that the superconductivity (SC) occurs close to an AF instability. From the T dependences of 1/T1and Knight shift below Tc, CeTIn5 has been found to exhibit non-s wave (probable d wave) SC with even parity and line nodes in the SC energy gap.

Kohara, T.

2002-05-01

86

Central role of the Na+-translocating NADH:quinone oxidoreductase (Na+-NQR) in sodium bioenergetics of Vibrio cholerae.  

PubMed

Abstract Vibrio cholerae is a Gram-negative bacterium that lives in brackish or sea water environments. Strains of V. cholerae carrying the pathogenicity islands infect the human gut and cause the fatal disease cholera. Vibrio cholerae maintains a Na+ gradient at its cytoplasmic membrane that drives substrate uptake, motility, and efflux of antibiotics. Here, we summarize the major Na+-dependent transport processes and describe the central role of the Na+-translocating NADH:quinone oxidoreductase (Na+-NQR), a primary Na+ pump, in maintaining a Na+-motive force. The Na+-NQR is a membrane protein complex with a mass of about 220 kDa that couples the exergonic oxidation of NADH to the transport of Na+ across the cytoplasmic membrane. We describe the molecular architecture of this respiratory complex and summarize the findings how electron transport might be coupled to Na+-translocation. Moreover, recent advances in the determination of the three-dimensional structure of this complex are reported. PMID:25205724

Steuber, Julia; Halang, Petra; Vorburger, Thomas; Steffen, Wojtek; Vohl, Georg; Fritz, Günter

2014-12-01

87

High Pressure NQR Measurement in CeCu2Si2 up to Sudden Disappearance of Superconductivity  

NASA Astrophysics Data System (ADS)

We report the results of 63Cu nuclear quadrupole resonance (NQR) measurements on CeCu2Si2 under high pressures up to 4.8 GPa. Enhanced spin fluctuations due to quantum criticality at ambient pressure are drastically suppressed with increasing pressure, whereas Tc increases from 0.7 K at ambient pressure to 1.64 K at 4.2 GPa. We have found that bulk superconductivity suddenly disappears at 4.8 GPa accompanied with a rapid decrease in the density of states at the Fermi level. The nuclear spin-lattice relaxation rate 1/T1 at 4.2 GPa reveals that anisotropic superconductivity in the strong-coupling regime is realized even under high pressure far from the antiferromagnetic critical point. Superconductivity under high pressure is unconventional in origin, but the spin fluctuation scenario is not likely to be applicable.

Fujiwara, Kenji; Hata, Yoshiki; Kobayashi, Keigo; Miyoshi, Kiyotaka; Takeuchi, Jun; Shimaoka, Yoshiyuki; Kotegawa, Hisashi; Kobayashi, Tatsuo C.; Geibel, Christoph; Steglich, Frank

2008-12-01

88

Magnetic correlations in La(2-x)Sr(x)CuO4 from NQR relaxation and specific heat  

NASA Technical Reports Server (NTRS)

La-139 and Cu-63 Nuclear Quadrupole Resonance (NQR) relaxation measurements in La(2-x)Sr(x)CuO4 for x ranging from 0 up to 0.3, with particular emphasis on the effect of doping on the Cu(2+) magnetic correlations and dynamics, are reviewed. In the low doping limit, x less than or equal to 0.05, the results can be interpreted consistently in terms of a simple phenomenological 'two-fluids' model whereby the effect of thermally-activated mobile O(2p) holes is the one of disrupting locally the Cu(2+) spin correlations. For x greater than or equal to 0.1, the results indicate the onset, as T approaches T(sub c)(+), of a strong coupling between Cu(2+) spins and the Fermi liquid of O(2p) holes leading to the apparent disappearance of localized Cu(2+) moment in connection with the opening of a superconducting gap.

Borsa, F.; Rigamonti, A.

1991-01-01

89

Synthesis and phtoluminescence study of Microporous Metal Organic Frameworks (MMOFs) for sensing and detection of nitroexplosives and aromatic compounds  

NASA Astrophysics Data System (ADS)

Due to the increased terrorist activity worldwide and the use of modern bombs in those attacks, the development of a new method capable of rapidly and cost-efficiently detecting trace vapor of explosives is highly desirable. Chemical explosives composed of a diverse group of compounds, including nitroaromatics, nitramines, nitrate esters as well as some inorganic/organic nitrates and peroxides. Current methodologies include use of well trained dogs and sophisticated instrumentation such as gas chromatography coupled with a mass spectrometer, nuclear quadruple resonance, ionization mass spectrometry (IMS). These methods are highly sensitive and selective, but often expensive, not always easily accessible, and require intense training for operation. As a complementary method, chemical sensors can provide new ways to the rapid detection of ultra trace explosives, and can be easily incorporated into inexpensive and portable microelectronic devices. Fluorescence based sensors utilizing conjugated polymers have attracted enormous attention in the recent years for their excellent performance. In this thesis, a systematic study was performed in a series of luminescent MMOFs and their behavior upon exposure to the vapor of different analytes. For example, [Zn2(oba)2(bpy)]·DMA, one of the MMOFs made of paddle-wheel SBU, selectively responds to nitroaromatics (with electron-withdrawing groups) and other aromatic compounds, like benzene, toluene (with electron-donating groups) via fluorescent quenching and enhancement respectively. The study also shows that nitro-containing non-aromatic analytes (nitroaliphatics) make negligible effect on the fluorescence of [Zn2(oba)2(bpy)]·DMA . The results demonstrate the exceptional ability of this particular MMOF to selectively detect explosives of different types (e.g. aromatic DNT vs. non-aromatic or aliphatic DMNB). Another series of highly luminescent MMOFs made of the same metal center (Zn) and similar ligands (bpdc, bpy, 2,2'dmbpy and bpe) but different structures have also been investigated. Photoluminescence studies show that the guest-free samples of these compounds also exhibit quenching or enhancement phenomena, when exposed to the vapors of two different types of analyte molecules having electron rich and electron deficient functional groups. The origin of such effect can be well understood and explained based on molecular orbital and band structure calculations, as well as the comparison of their redox potentials. In addition, synthesis and characterization of some new MMOFs, composed of V-shaped dicarboxylic acid and selected diamine ligands are briefly discussed. Clearly, ligands play an important role in the crystal structure formation as well as pore characteristics of the resultant MMOFs.

Pramanik, Sanhita

90

NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts  

SciTech Connect

Copper and cobalt are the key elements in syngas conversion catalyst systems used for higher alcohol synthesis. Their proximity and synergy sensitively control the selectivity and efficiency of the process. It is believed that their outer electronic charge distribution which is responsible for their electrical and magnetic properties might be governing their catalytic properties also. To examine the correlation between catalytic and magnetic properties, a series of copper cobalt catalysts (Co/Cu ratio 5:1 to 5:5) with and without a support were prepared. The nuclear quadrupole resonance spectrum of copper and (zero-field) nuclear magnetic resonance spectrum of cobalt and magnetization and hysteresis character of the catalyst were analyzed. Similar to the catalytic results, the magnetic results also were found to be very sensitive to the preparation technique. The results indicate possible electron exchange between copper and cobalt, and cobalt and the support Titania.

Not Available

1991-01-14

91

Copper NMR and NQR studies of fluorine-doped electron superconductors  

SciTech Connect

We report the observation of a Cu NMR signal with a pronounced quadrupole splitting (V[sub Q] approximately 13 MHz) in Nd[sub 2]CuO[sub 4[minus]y]F[sub y]. This finding gives evidence that the electric-field gradient (EFG) in electron-doped superconducting compound is almost the same as for undoped parent ones. In view of this result, the mysterious absence of an EFG, reported before for similar Ce-doped compounds, is discussed. It is attributed to the appearance of spherically symmetric d[sup 10] configuration with doping. It is more likely connected with the inhomogeneities of the quadropole splitting induced by doping, rather than with the changes of electronic configuration. 9 refs., 2 figs.

Kukovitsky, E. (Inst. of Technical Physics, Kazan (Russian Federation)); Luetgemeier, H. (Forschungzentrum Juelich (Germany)); Teitel'baum, G. (Inst. of Technical Physics, Kazan (Russian Federation) Forschungzentrum Juelich (Germany))

1994-04-01

92

Oxygen isotope effect of the plane-copper NQR frequency in YBa2Cu4O8  

NASA Astrophysics Data System (ADS)

We report high-precision measurements of the temperature dependence of the plane-63Cu NQR line frequency ?Q(Cu2) and the linewidth in normal and superconducting 16O and 18O-exchanged YBa2Cu4O8. Whereas ?Q(Cu2) passes Tc very smoothly without a discontinuity either in value or slope, the linewidth increases in the normal conducting phase down to Tc and starts to decrease sharply in the superconducting phase to finally resume its high-temperature value of the normal phase. There is a well discernible oxygen isotope effect on the ?Q(Cu2) temperature dependencies. The temperature dependence of ?Q(Cu2) is described by an empirical expression consisting of two parts, one related to the thermal expansion of the lattice and the other due to charge redistribution during the formation of new electronic structures in the CuO2 planes. From the fit to the experimental data we determine for the conjectured formation of new electronic structures an energy scale ?(16O)=188.0(1.6) K and ?(18O)=180.0(1.6) K. This results in a partial oxygen isotope effect coefficient ??Q=0.42(11) which is larger than both the spin pseudogap coefficient ?PG=0.061(8) and the Tc coefficient ?Tc=0.056(12) [F. Raffa, T. Ohno, M. Mali, J. Roos, D. Brinkmann, K. Conder, and M. Eremin, Phys. Rev. Lett. 81, 5912 (1998)].

Mali, M.; Roos, J.; Keller, H.; Karpinski, J.; Conder, K.

2002-05-01

93

Field-tuned critical fluctuations in YFe2Al10: Evidence from magnetization, 27Al NMR, and NQR investigations  

NASA Astrophysics Data System (ADS)

We report magnetization, specific heat, and NMR investigations on YFe2Al10 over a wide range of temperature and magnetic field and zero field (NQR) measurements. Magnetic susceptibility, specific heat, and spin-lattice relaxation rate divided by T(1/T1T) follow a weak power law (˜T-0.4) temperature dependence, which is a signature of the critical fluctuations of Fe moments. The value of the Sommerfeld-Wilson ratio and the linear relation between 1/T1T and ? suggest the existence of ferromagnetic correlations in this system. No magnetic ordering down to 50 mK in Cp(T)/T and the unusual T and H scaling of the bulk and NMR data are associated with a magnetic instability which drives the system to quantum criticality. The magnetic properties of the system are tuned by field wherein ferromagnetic fluctuations are suppressed and a crossover from quantum critical to Fermi-liquid behavior is observed with increasing magnetic field.

Khuntia, P.; Strydom, A. M.; Wu, L. S.; Aronson, M. C.; Steglich, F.; Baenitz, M.

2012-12-01

94

Magnetic correlations in La(2-x)Sr(x)CuO4 from NQR relaxation and specific heat  

NASA Technical Reports Server (NTRS)

La-139 and Cu-63 Nuclear Quadrupole Resonance (NQR) relaxation measurements in La(2-x)Sr(x)CuO4 for O = to or less than 0.3 and in the temperature range 1.6 + 450 K are analyzed in terms of Cu(++) magnetic correlations and dynamics. It is described how the magnetic correlations that would result from Cu-Cu exchange are reduced by mobile charge defects related to x-doping. A comprehensive picture is given which explains satisfactorily the x and T dependence of the correlation time, of the correlation length and of the Neel temperature T(sub n)(x) as well as being consistent with known electrical resistivity and magnetic susceptibility measurements. It is discussed how, in the superconducting samples, the mobile defects also cause the decrease, for T yields T(sub c)(+) of the hyperfine Cu electron-nucleus effective interaction, leading to the coexistence of quasi-localized, reduced magnetic moments from 3d Cu electrons and mobile oxygen p-hole carriers. The temperature dependence of the effective hyperfine field around the superconducting transition yields an activation energy which could be related to the pairing energy. New specific heat measurements are also presented and discussed in terms of the above picture.

Borsa, F.; Rigamonti, A.

1990-01-01

95

Zero-field NMR study on a spin glass: iron-doped 2H-niobium diselenide  

SciTech Connect

Spin echoes are used to study the /sup 93/Nb NQR in 2H-NbSe/sub 2/Fe/sub x/. Measured are (intensity) x (temperature), and T/sub 1P/ (spin-lattice relaxation parameter) and T/sub 2/ (spin-spin relaxation time) as a function of temperature. Data reveal dramatic differences between non-spin glass samples (x = 0, 0.25%, 1% and 5%) and spin glass samples (x = 8%, 10% and 12%). All of the NQR results and the model calculation of the correlation times of Fe spins are best described by the phase transition picture of spin glasses.

Chen, M C

1982-01-01

96

NMR and NQR studies of the heavy fermion superconductors CeTIn5 (T=Co and Ir)  

Microsoft Academic Search

We have carried out 115In and 59Co nuclear quadrupole resonance and nuclear magnetic resonance measurements on CeCoIn5 and CeIrIn5. The temperature T dependence of the nuclear spin-lattice relaxation rate 1\\/T1 of 115In in the normal state indicates that CeCoIn5 is located just at an antiferromagnetic instability, and CeIrIn5 is in the nearly antiferromagnetic region. In the superconducting state, 1\\/T1 has

Y. Kohori; Y. Yamato; Y. Iwamoto; T. Kohara; E. D. Bauer; M. B. Maple; J. L. Sarrao

2001-01-01

97

Hybridization-driven gap in U3Bi4Ni3: a 209Bi NMR/NQR study  

SciTech Connect

We report {sup 209}Bi nuclear-magnetic-resonance and nuclear-quadrupole-resonance measurements on a single crystal of the Kondo insulator U{sub 3}Bi{sub 4}Ni{sub 3}. The {sup 209}Bi nuclear-spin-lattice relaxation rate (T{sub 1}{sup -1}) shows activated behavior and is well fit by a spin gap of 220 K. The {sup 209}Bi Knight shift (K) exhibits a strong temperature dependence arising from 5f electrons, in which K is negative at high temperatures and increases as the temperature is lowered. Below 50 K, K shows a broad maximum and decreases slightly upon further cooling. Our data provide insight into the evolution of the hyperfine fields in a fully gapped Kondo insulator based on 5f electron hybridization.

Baek, Seung H [Los Alamos National Laboratory

2009-01-01

98

A study of the semiconductor compound ?uAlO2 by the method of nuclear quadrupole resonance of Cu  

NASA Astrophysics Data System (ADS)

The method of nuclear quadrupole resonance of Cu (NQR Cu) is used to study the samples of a semiconductor compound CuAlO2. The crystal structure of CuAlO2 belongs to the family of delafossite - the mineral of a basic CuFeO2 structure. Transparent semiconductor oxides, such as CuAlO2, have attracted recent attention as promising thermoelectric materials.

Matukhin, V. L.; Khabibulin, I. Kh.; Shul'gin, D. A.; Smidt, S. V.

2012-07-01

99

Nuclear quadrupole resonance studies of the SORC sequence and nuclear magnetic resonance studies of polymers  

SciTech Connect

The behavior of induction signals during steady-state pulse irradiation in {sup 14}N NQR was investigated experimentally. Because Strong Off-resonance Comb (SORC) signals recur as long as the pulsing continues, very efficient signal-averaging can result. The dependence of these steady-state SORC signals on pulse parameters and on frequency offset are presented, together with a discussion of the applicability of the method. Also as part of the NQR work, cocaine base has been detected using conventional NQR techniques. The experimental results show that SORC detection can be of sufficient sensitivity to form the basis of narcotics screening devices for both mail and airline baggage. A new NMR technique, to obtain the correlation time of the random thermal motion of a polymer at temperatures near the glass transition has been introduced. The temperature dependence is a result of thermal motion. For slow-motion of a polymer chain near the glass transition, the CSA parameter begins to decrease. This motional narrowing can be interpreted to yield the correlation time of the thermal motion. In this work nitrocellulose isotopically highly enriched with {sup 15}N was studied at four different temperatures between 27{degrees} and 120{degrees} Celsius and the correlation times for polymer backbone motions were obtained. Naflon films containing water (D{sub 2}O and H{sub 2} {sup 17}O) and methanol (CH{sub 3}OD, CH{sub 3} {sup 17}OH), have been studied using deuteron and oxygen-17 NMR spectroscopy. Glassy behavior of the water domains at low temperature is evidenced by the specific nature of the {sup 2}H NMR lineshapes. Activation energies extracted from {sup 2}H spin-lattice relaxation data on the high temperature side of the T{sub 1} minimum exhibit a steady increase with increasing water content. In spite of a high degree of molecular mobility, angular-dependent spectra of both unstretched and stretched samples reflect considerable anisotrophy of the host polymer.

Jayakody, J.R.P.

1993-12-31

100

Zero field NMR and NQR  

Microsoft Academic Search

Methods are described and demonstrated for detecting the coherent evolution of nuclear spin observables in zero magnetic field with the full sensitivity of high field NMR. The principle motivation is to provide a means of obtaining solid state spectra of the magnetic dipole and electric quadrupole interactions of disordered systems without the line broadening associated with random orientation with respect

D. B. Zax; A. Bielecki; K. W. Zilm; A. Pines; D. P. Weitekamp

1985-01-01

101

NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts. Quarterly technical progress report, September 14--December 15, 1990  

SciTech Connect

Copper and cobalt are the key elements in syngas conversion catalyst systems used for higher alcohol synthesis. Their proximity and synergy sensitively control the selectivity and efficiency of the process. It is believed that their outer electronic charge distribution which is responsible for their electrical and magnetic properties might be governing their catalytic properties also. To examine the correlation between catalytic and magnetic properties, a series of copper cobalt catalysts (Co/Cu ratio 5:1 to 5:5) with and without a support were prepared. The nuclear quadrupole resonance spectrum of copper and (zero-field) nuclear magnetic resonance spectrum of cobalt and magnetization and hysteresis character of the catalyst were analyzed. Similar to the catalytic results, the magnetic results also were found to be very sensitive to the preparation technique. The results indicate possible electron exchange between copper and cobalt, and cobalt and the support Titania.

Not Available

1991-01-14

102

87Rb and 85Rb NQR study of phase transitions in RbH3(SeO3)2 J. Seliger, V. 017Dagar, R. Blinc  

E-print Network

dependence of the quadrupole coupling constants and the asymmetry parameters on going into the ferroelectric SeO3. Nous avons confirmé l'existence d'une phase incommensurable intermédiaire entre Tc et Tc + 4 K. Abstract. 2014 The temperature dependence of the nuclear quadrupole resonance spectra of 85Rb and 87Rb

Paris-Sud XI, Université de

103

Nuclear Quadrupole Resonance Studies of the Sorc Sequence and Nuclear Magnetic Resonance Studies of Polymers.  

NASA Astrophysics Data System (ADS)

The behavior of induction signals during steady -state pulse irradiation in ^{14} N NQR was investigated experimentally. Because Strong Off-resonance Comb (SORC) signals recur as long as the pulsing continues, very efficient signal-averaging can result. The dependence of these steady-state SORC signals on pulse parameters and on frequency offset are presented, together with a discussion of the applicability of the method. Also as part of the NQR work, Cocaine base has been detected using conventional NQR techniques. The experimental results show that SORC detection can be of sufficient sensitivity to form the basis of narcotics screening devices for both mail and airline baggage. A new NMR technique, to obtain the correlation time of the random thermal motion of a polymer at temperatures near the glass transition has been introduced. The temperature dependence is a result of thermal motion. For slow-motion of a polymer chain near the glass transition, the CSA parameter begins to decrease. This motional narrowing can be interpreted to yield the correlation time of the thermal motion. In this work Nitrocellulose isotopically highly enriched with ^{15}N was studied at four different temperatures between 27^ circ and 120^circ Celsius and the correlation times for polymer backbone motions were obtained. Nafion films containing, water (D_2 O and H_2^{17}O) and methanol (CH_3OD, CH _3^{17}OH), have been studied using Deuteron and Oxygen-17 NMR spectroscopy. Glassy behavior of the water domains at low temperature is evidenced by the specific nature of the ^2H NMR lineshapes. Activation energies extracted from ^2H spin-lattice relaxation data on the high temperature side of the T_1 minimum exhibit a steady increase with increasing water content. In spite of a high degree of molecular mobility, angular-dependent spectra of both unstretched and stretched samples reflect considerable anisotropy of the host polymer. Activation volumes corresponding to a specific dynamical process were obtained from measurements of spin-lattice relaxation vs. pressure. From the NMR measurements of Nafion films containing methanol, it was found that the molecular motion is much more rapid than the molecular motion of water in Nafion membranes.

Jayakody, Jayakody R. Pemadasa

1993-01-01

104

Zero Field NMR Study on a Spin Glass: Iron-Doped 2HYDROGEN-NIOBIUM Diselenide.  

NASA Astrophysics Data System (ADS)

We have used spin echoes to study the ('93)Nb NQR in 2H-NbSe(,2)Fe(,x). We measured (intensity) x (temperature), and T(,1P) (spin-lattice relaxation parameter) and T(,2) (spin-spin relaxation time) as a function of temperature. Our data reveal dramatic difference between non-spin glass samples (x = 0, 0.25%, 1% and 5%) and spin glass samples (x = 8%, 10% and 12%). Defining the spin glass transition temperature T(,g) by the cusp of the susceptibility versus temperature curve, we find well-defined minima at T = T(,g) in (intensity) x (temperature), T(,1P) and T(,2) as a function of temperature. Deduction of a correlation time of Fe spins from T(,1P) and T(,2) is complicated by the intensity changes which imply that one observes different groups of nuclei at different temperatures. We propose a two -correlation-time model, which utilizes the anisotropy of the exchange interaction, to overcome this difficulty. All of our NQR results and the model calculation of the correlation times of Fe spins are best described by the phase transition picture of spin glasses.

Chen, Men-Chee

1982-03-01

105

Sb-NQR probe for superconducting properties in the Pr-based filled-skutterudite compound PrRu4Sb12  

NASA Astrophysics Data System (ADS)

We report the electronic and superconducting properties in the Pr-based filled-skutterudite superconductor PrRu4Sb12 with Tc=1.3 K via the measurements of nuclear-quadrupole-resonance frequency ?Q and nuclear-spin-lattice-relaxation time T1 of Sb nuclei. The temperature dependence of ?Q has revealed the energy scheme of Pr3+ crystal electric field that is consistent with an energy separation ?CEF˜70 K between the ground state and the first-excited state. In the normal state, the Korringa relation of (1/T1T)Pr=const is valid, with [(1/T1T)Pr/(1/T1T)La]1/2˜1.44, where (1/T1T)La is for LaRu4Sb12. These results are understood in terms of a conventional Fermi-liquid picture in which the Pr-4f2 state derives neither magnetic nor quadrupolar degrees of freedom at low temperatures. In the superconducting state, 1/T1 shows a distinct coherence peak just below Tc, followed by an exponential decrease with a value of 2?/kBTc=3.1. These results demonstrate that PrRu4Sb12 is a typical weak-coupling s-wave superconductor, in strong contrast with the heavy-fermion superconductor PrOs4Sb12 that is in an unconventional strong coupling regime. The present study on PrRu4Sb12 highlights that the Pr-4f2-derived nonmagnetic doublet plays a key role in the unconventional electronic and superconducting properties in PrOs4Sb12.

Yogi, M.; Kotegawa, H.; Imamura, Y.; Zheng, G.-Q.; Kitaoka, Y.; Sugawara, H.; Sato, H.

2003-05-01

106

Undergraduate research studies program at participating institutions of the HBCU Fossil Energy Consortium  

SciTech Connect

The primary objective of this research program is to expose students in the Historically Black Colleges and Universities (HBCU) Fossil Energy Consortium Institutions to energy and fossil fuels research, to stimulate their interest in the sciences and engineering and to encourage them to pursue graduate studies. This report provides the research accomplishment of the various students who participated in the program. Research results are presented on the following topics: Energy Enhancement and Pollutant Reduction in Coal by Cryogenic Diminution; Competition of NO and SO[sub 2] for OH Generated witin Electrical Aerosol Analyzers; Dispersed Iron Catalysts for Coal Gasification; NQR/NMR Studies of Copper-Cobalt Catalysts for Syngas Concersion; Catalytic gasification of Coal Chars by Potassium Sulfate and Ferrous Sulfate Mixtures; A New Method for Cleaning and Beneficiation of Ultrafine Coal; Characterization Studies of Coal-Derived Liquids; Study of Coal Liquefaction Catalysts and Removal of Certain Toxic Heavy Metal Ions from Coal Conversion Process Wastewaters.

Bota, K.B.

1991-01-01

107

Undergraduate research studies program at participating institutions of the HBCU Fossil Energy Consortium. Final report  

SciTech Connect

The primary objective of this research program is to expose students in the Historically Black Colleges and Universities (HBCU) Fossil Energy Consortium Institutions to energy and fossil fuels research, to stimulate their interest in the sciences and engineering and to encourage them to pursue graduate studies. This report provides the research accomplishment of the various students who participated in the program. Research results are presented on the following topics: Energy Enhancement and Pollutant Reduction in Coal by Cryogenic Diminution; Competition of NO and SO{sub 2} for OH Generated witin Electrical Aerosol Analyzers; Dispersed Iron Catalysts for Coal Gasification; NQR/NMR Studies of Copper-Cobalt Catalysts for Syngas Concersion; Catalytic gasification of Coal Chars by Potassium Sulfate and Ferrous Sulfate Mixtures; A New Method for Cleaning and Beneficiation of Ultrafine Coal; Characterization Studies of Coal-Derived Liquids; Study of Coal Liquefaction Catalysts and Removal of Certain Toxic Heavy Metal Ions from Coal Conversion Process Wastewaters.

Bota, K.B.

1991-12-31

108

Utilization of pure nuclear quadrupole resonance spectroscopy for the study of pharmaceutical crystal forms.  

PubMed

Solid-state physical characterization of a pharmaceutical substance is necessary for successful development and approval of the final product. Different physical analytical techniques are available to do so: X-ray diffraction (XRD), IR, Raman, DSC, TG and NMR. Moreover, all of them detect the presence of excipients perturbing the analysis of the pure substance in low doses. In order to study polymorphism and pseudo polymorphism of drug, this paper introduces possible applications of pure nuclear quadrupole resonance, as a non-destructive technique in qualitative and quantitative approaches. Chlorpropamide and diclofenac sodium were used as examples. Unlike the mentioned techniques, the nuclear quadrupole resonance (NQR) signal of pharmaceutical compounds is not perturbed by the presence of solid excipient or other substances unless they possess resonance frequencies in the same frequency range of the compound studied. PMID:15913931

Pérez, S C; Cerioni, L; Wolfenson, A E; Faudone, S; Cuffini, S L

2005-07-14

109

35Cl nuclear quadrupole resonance study in 4,4'-dichlorobiphenyl sulphone: A possible incommensurate system  

Microsoft Academic Search

Pulsed nuclear quadrupole resonance (NQR) has been used to get information about the nature of the molecular dynamics in two crystalline phases of 4,4'-dichlorobiphenyl sulphone. This work includes detailed experimental measurements of the NQR frequency, spin-lattice relaxation time, and line intensity temperature behavior in the range of temperature where a possible normal-to-incommensurate phase transition occurs. The experimental results show the

D. J. Pusiol; A. E. Wolfenson; A. H. Brunetti

1989-01-01

110

Origin and Evolution of the Sodium -Pumping NADH: Ubiquinone Oxidoreductase  

PubMed Central

The sodium -pumping NADH: ubiquinone oxidoreductase (Na+-NQR) is the main ion pump and the primary entry site for electrons into the respiratory chain of many different types of pathogenic bacteria. This enzymatic complex creates a transmembrane gradient of sodium that is used by the cell to sustain ionic homeostasis, nutrient transport, ATP synthesis, flagellum rotation and other essential processes. Comparative genomics data demonstrate that the nqr operon, which encodes all Na+-NQR subunits, is found in a large variety of bacterial lineages with different habitats and metabolic strategies. Here we studied the distribution, origin and evolution of this enzymatic complex. The molecular phylogenetic analyses and the organizations of the nqr operon indicate that Na+-NQR evolved within the Chlorobi/Bacteroidetes group, after the duplication and subsequent neofunctionalization of the operon that encodes the homolog RNF complex. Subsequently, the nqr operon dispersed through multiple horizontal transfer events to other bacterial lineages such as Chlamydiae, Planctomyces and ?, ?, ? and ? -proteobacteria. Considering the biochemical properties of the Na+-NQR complex and its physiological role in different bacteria, we propose a detailed scenario to explain the molecular mechanisms that gave rise to its novel redox- dependent sodium -pumping activity. Our model postulates that the evolution of the Na+-NQR complex involved a functional divergence from its RNF homolog, following the duplication of the rnf operon, the loss of the rnfB gene and the recruitment of the reductase subunit of an aromatic monooxygenase. PMID:24809444

Reyes-Prieto, Adrian; Barquera, Blanca; Juárez, Oscar

2014-01-01

111

Origin and evolution of the sodium -pumping NADH: ubiquinone oxidoreductase.  

PubMed

The sodium -pumping NADH: ubiquinone oxidoreductase (Na+-NQR) is the main ion pump and the primary entry site for electrons into the respiratory chain of many different types of pathogenic bacteria. This enzymatic complex creates a transmembrane gradient of sodium that is used by the cell to sustain ionic homeostasis, nutrient transport, ATP synthesis, flagellum rotation and other essential processes. Comparative genomics data demonstrate that the nqr operon, which encodes all Na+-NQR subunits, is found in a large variety of bacterial lineages with different habitats and metabolic strategies. Here we studied the distribution, origin and evolution of this enzymatic complex. The molecular phylogenetic analyses and the organizations of the nqr operon indicate that Na+-NQR evolved within the Chlorobi/Bacteroidetes group, after the duplication and subsequent neofunctionalization of the operon that encodes the homolog RNF complex. Subsequently, the nqr operon dispersed through multiple horizontal transfer events to other bacterial lineages such as Chlamydiae, Planctomyces and ?, ?, ? and ? -proteobacteria. Considering the biochemical properties of the Na+-NQR complex and its physiological role in different bacteria, we propose a detailed scenario to explain the molecular mechanisms that gave rise to its novel redox- dependent sodium -pumping activity. Our model postulates that the evolution of the Na+-NQR complex involved a functional divergence from its RNF homolog, following the duplication of the rnf operon, the loss of the rnfB gene and the recruitment of the reductase subunit of an aromatic monooxygenase. PMID:24809444

Reyes-Prieto, Adrian; Barquera, Blanca; Juárez, Oscar

2014-01-01

112

Detecting body cavity bombs with nuclear quadrupole resonance  

NASA Astrophysics Data System (ADS)

Nuclear Quadrupole Resonance (NQR) is a technology with great potential for detecting hidden explosives. Past NQR research has studied the detection of land mines and bombs concealed within luggage and packages. This thesis focuses on an NQR application that has received less attention and little or no publicly available research: detecting body cavity bombs (BCBs). BCBs include explosives that have been ingested, inserted into orifices, or surgically implanted. BCBs present a threat to aviation and secure facilities. They are extremely difficult to detect with the technology currently employed at security checkpoints. To evaluate whether or not NQR can be used to detect BCBs, a computational model is developed to assess how the dielectric properties of biological tissue affect the radio frequency magnetic field employed in NQR (0.5-5MHz). The relative permittivity of some biological tissue is very high (over 1,000 at 1MHz), making it conceivable that there is a significant effect on the electromagnetic field. To study this effect, the low-frequency approximation known as the Darwin model is employed. First, the electromagnetic field of a coil is calculated in free space. Second, a dielectric object or set of objects is introduced, and the free-space electric field is modified to accommodate the dielectric object ensuring that the relevant boundary conditions are obeyed. Finally, the magnetic field associated with the corrected electric field is calculated. This corrected magnetic field is evaluated with an NQR simulation to estimate the impact of dielectric tissue on NQR measurements. The effect of dielectric tissue is shown to be small, thus obviating a potential barrier to BCB detection. The NQR model presented may assist those designing excitation and detection coils for NQR. Some general coil design considerations and strategies are discussed.

Collins, Michael London

113

Evidence for Unconventional Strong-Coupling Superconductivity in PrOs4Sb12: An Sb Nuclear Quadrupole Resonance Study  

Microsoft Academic Search

We report Sb-NQR results which evidence a heavy-fermion (HF) behavior and an unconventional superconducting (SC) property in Pr(Os4Sb12 with Tc=1.85 K. The temperature (T) dependence of nuclear-spin-lattice-relaxation rate, 1\\/T1, and NQR frequency unravel a low-lying crystal-electric-field splitting below T0˜10 K, associated with Pr3+(4f2)-derived ground state. In the SC state, 1\\/T1 shows neither a coherence peak just below Tc K nor

H. Kotegawa; M. Yogi; Y. Imamura; Y. Kawasaki; G.-Q. Zheng; Y. Kitaoka; S. Ohsaki; H. Sugawara; Y. Aoki; H. Sato

2003-01-01

114

35Cl nuclear quadrupolar resonance study of 4,4'-dichlorobiphenyl sulphone  

Microsoft Academic Search

Pulsed NQR spectroscopy was used to search for a structural phase transition from a normal to an incommensurate phase and others in 4,4'-dichlorobiphenyl sulphone. The experimental results show the existence of a structural phase transition to an incommensurate phase at 150 K and another transition to a possible commensurate phase at 110 K.

J. M. Corberó; A. E. Wolfenson; D. J. Pusiol; A. H. Brunetti

1986-01-01

115

Nuclear Quadrupole Resonance Studies of the Sorc Sequence and Nuclear Magnetic Resonance Studies of Polymers  

Microsoft Academic Search

The behavior of induction signals during steady -state pulse irradiation in ^{14} N NQR was investigated experimentally. Because Strong Off-resonance Comb (SORC) signals recur as long as the pulsing continues, very efficient signal-averaging can result. The dependence of these steady-state SORC signals on pulse parameters and on frequency offset are presented, together with a discussion of the applicability of the

Jayakody R. Pemadasa Jayakody

1993-01-01

116

Strong coupling between antiferromagnetic and superconducting order parameters of CeRhIn5 studied by I115n nuclear quadrupole resonance spectroscopy  

Microsoft Academic Search

We report on a pressure (P) -induced evolution of magnetism and superconductivity (SC) in a helical magnet CeRhIn5 with an incommensurate wave vector Qi=((1)\\/(2),(1)\\/(2),0.297) through the I115n nuclear quadrupole resonance (NQR) measurements under P . Systematic measurements of the I115n -NQR spectrum reveal that the commensurate antiferromagnetism (AFM) with Qc=((1)\\/(2),(1)\\/(2),(1)\\/(2)) is realized above Pm˜1.7GPa . An important finding is that

M. Yashima; H. Mukuda; Y. Kitaoka; H. Shishido; R. Settai; Y. Onuki

2009-01-01

117

Multiband Superconductivity in Filled-Skutterudite Compounds (Pr1-xLax)Os4Sb12: An Sb Nuclear-Quadrupole-Resonance Study  

Microsoft Academic Search

We report on the systematic evolution of normal-state properties and superconducting characteristics in filled-skutterudite compounds (Pr1-xLax)Os4Sb12 determined using Sb nuclear-quadrupole-resonance (NQR) experiments. The Sb-NQR spectra in these compounds have split into two sets, arising from different Sb12 cages containing either Pr or La, which enables us to measure two kinds of nuclear spin-lattice relaxation time T1Pr and T1La. In the

Mamoru Yogi; Takayuki Nagai; Yojyu Imamura; Hidekazu Mukuda; Yoshio Kitaoka; Daisuke Kikuchi; Hitoshi Sugawara; Yuji Aoki; Hideyuki Sato; Hisatomo Harima

2006-01-01

118

Nuclear quadrupole resonance of Cl 35 , Br 79 , Br 81 , and I 127 of halogen-containing organomercury compounds  

Microsoft Academic Search

1.The NQR spectra of halogens in a number of organomercury compounds of the RHgHal and p-ClC6 H4HgX types were investigated.2.In crystals of the compounds studied, coordination interactions arise between the mercury atoms and the halogens. However, when the type of coordination is preserved within a narrow series of compounds, the changes in the NQR frequencies may be determined by the

A. N. Nesmeyanov; O. Yu. Okhlobystin; E. V. Bryukhova; V. I. Bregadze; D. N. Kravtsov; B. A. Faingor; L. S. Golovchenko; G. K. Semin

1969-01-01

119

Superconductivity and Magnetic Fluctuations in Cd2Re2O7 via Cd Nuclear Magnetic Resonance and Re Nuclear Quadrupole Resonance  

Microsoft Academic Search

We report Cd nuclear magnetic resonance (NMR) and Re nuclear quadrupole resonance (NQR) studies on Cd 2Re2O7, the first superconductor among pyrochlore oxides (Tc~=1 K). The Re NQR spectrum at zero magnetic field below 100 K rules out any magnetic or charge order. The spin-lattice relaxation rate below Tc exhibits a pronounced coherence peak and follows the weak-coupling BCS theory

O. Vyaselev; K. Arai; K. Kobayashi; J. Yamazaki; K. Kodama; M. Takigawa; M. Hanawa; Z. Hiroi

2002-01-01

120

NMR study of the pseudogap in lead strontium (yttrium, calcium) copper oxide crystals  

NASA Astrophysics Data System (ADS)

In this thesis, we report Cu NMR/NQR studies of the high temperature superconductor Pb2Sr2(Y,Ca)Cu3O8 ( Tc= 80 K) using slightly underdoped crystals. The structure of Pb 2Sr2(Y,Ca)Cu3O8 contains two different Cu sites: Cu(2) in the CuO2 plane and an oxygen-free Cu(1) layer. The quadrupolar frequencies, 31.957 MHz and 29.88 MHz for 63Cu(1) and 63Cu (2) sites, respectively, have been obtained from the NQR spectrum. The Cu(1) line is narrow with a linewidth of 0.44 MHz, whereas the Cu(2) line is broad with a linewidth of 1.81 MHz, due to the inhomogeneity of electric field gradients (EFG) from the Ca+2/Y+3 layers. We have obtained Cu(1) and Cu(2) NMR spectra. From the analysis of the field-dependent measurements, we found that the tilting of the EFG principal axis with respect to c-axis at the Cu(1) site is more than that at the Cu(2) site. The EFGs from the two nearest oxygen ions above and below Cu(1) are responsible for this extra tilting. The spin-lattice relaxation time obtained at T = 85 K for Cu(1) and Cu(2) are 15.5 sec and 520 mus respectively. The much longer relaxation time in Cu(1) is consistent with band structure calculations indicating that Cu(1) makes an extremely small contribution to the density of states at the Fermi surface. The temperature dependence of the Knight shift and the spin-lattice relaxation rate for both Cu(1) and Cu(2) sites has been measured. Our analysis shows that the relaxation for Cu(1) is due to a quadrupolar-phonon coupling mechanism. We have observed a pseudogap in the Cu(2) Knight shift and spin-lattice relaxation rate. In contrast to other underdoped compounds, the pseudogap observed in the Knight shift is weak and occurs at a significantly lower temperature. On the other hand, the effect that the pseudogap has on spin-lattice relaxation is quite similar to the observed behaviour in other compounds. The manifestation of the pseudogap, at q=0 is different than that at q= Q. The evidence and some qualitative theories of the pseudogap are reviewed and discussed in terms of experimental data, with emphasis on our NMR data. The spin-lattice relaxation rate anisotropy measurements at Cu(2) sites reveal that the hyperfine coupling constants are temperature independent and the hybridization between Cu(3d)-O(2p)-Cu(4s) orbits in PSYCCO are stronger than in Y-compounds.

Hsueh, Ya-Wei

1998-12-01

121

Heavy-fermion like behavior of amorphous CexMn100-x alloys system studied by 55Mn NMR  

Microsoft Academic Search

In order to investigate a heavy-fermion like behavior on Ce-rich side of amorphous CexMn100-x alloys system, the 55Mn NMR measurements on the powdered sample of amorphous Ce62Y19Mn19, being diluted with non-magnetic Y, have been carried out in the temperature range from 1.8 to 270 K. A broadened resonance spectrum containing five NQR lines is observed in the measuring temperature region.

H. Niki; K. Okamura; R. Mahoe; M. Yogi; Y. Amakai; H. Takano; S. Murayama; Y. Obi

2009-01-01

122

Pulsed Fourier-transform NQR of sup 14 N with a dc SQUID  

SciTech Connect

The zero-field free induction decay of solid ammonium perchlorate at 1.5 K has been directly detected with a dc superconducting quantum interference device. The Fourier-transform spectrum consists of three sharp lines at 17.4, 38.8, and 56.2 kHz arising from pure {sup 14}N nuclear quadrupole resonance transitions. The absence of splittings and resonance transitions from dipolar-coupled proton spins is attributed to reorientation of the ammonium groups by quantum tunneling in combination with motional averaging in the three proton levels characterized by the irreducible representation {ital T}. The measured {sup 14}N spin-spin relaxation time is 22{plus minus}2 ms and the spin-lattice relaxation time is 63{plus minus}6 ms.

Huerlimann, M.D.; Pennington, C.H.; Fan, N.Q.; Clarke, J.; Pines, A.; Hahn, E.L. (Department of Physics, University of California, Berkeley, Berkeley, California 94720 (United States) Department of Chemistry, University of California, Berkeley, Berkeley, California 94720 (United States) Materials Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States))

1992-07-27

123

Strong coupling between antiferromagnetic and superconducting order parameters of CeRhIn5 studied by I115n nuclear quadrupole resonance spectroscopy  

NASA Astrophysics Data System (ADS)

We report on a pressure (P) -induced evolution of magnetism and superconductivity (SC) in a helical magnet CeRhIn5 with an incommensurate wave vector Qi=((1)/(2),(1)/(2),0.297) through the I115n nuclear quadrupole resonance (NQR) measurements under P . Systematic measurements of the I115n -NQR spectrum reveal that the commensurate antiferromagnetism (AFM) with Qc=((1)/(2),(1)/(2),(1)/(2)) is realized above Pm˜1.7GPa . An important finding is that the size of SC gap and Tc increase as the magnitude of the AFM moment decreases in the P region, where SC uniformly coexists with the commensurate AFM. This result provides evidence of strong coupling between the commensurate AFM order parameter (OP) and SC OP.

Yashima, M.; Mukuda, H.; Kitaoka, Y.; Shishido, H.; Settai, R.; ?nuki, Y.

2009-06-01

124

Nuclear magnetic resonance studies of quadrupolar nuclei and dipolar field effects  

SciTech Connect

Experimental and theoretical research conducted in two areas in the field of nuclear magnetic resonance (NMR) spectroscopy is presented: (1) studies of the coherent quantum-mechanical control of the angular momentum dynamics of quadrupolar (spin I > 1/2) nuclei and its application to the determination of molecular structure; and (2) applications of the long-range nuclear dipolar field to novel NMR detection methodologies.The dissertation is organized into six chapters. The first two chapters and associated appendices are intended to be pedagogical and include an introduction to the quantum mechanical theory of pulsed NMR spectroscopy and the time dependent theory of quantum mechanics. The third chapter describes investigations of the solid-state multiple-quantum magic angle spinning (MQMAS) NMR experiment applied to I = 5/2 quadrupolar nuclei. This work reports the use of rotary resonance-matched radiofrequency irradiation for sensitivity enhancement of the I = 5/2 MQMAS experiment. These experiments exhibited certain selective line narrowing effects which were investigated theoretically.The fourth chapter extends the discussion of multiple quantum spectroscopy of quadrupolar nuclei to a mostly theoretical study of the feasibility of enhancing the resolution of nitrogen-14 NMR of large biomolecules in solution via double-quantum spectroscopy. The fifth chapter continues to extend the principles of multiple quantum NMR spectroscopy of quadrupolar nuclei to make analogies between experiments in NMR/nuclear quadrupolar resonance (NQR) and experiments in atomic/molecular optics (AMO). These analogies are made through the Hamiltonian and density operator formalism of angular momentum dynamics in the presence of electric and magnetic fields.The sixth chapter investigates the use of the macroscopic nuclear dipolar field to encode the NMR spectrum of an analyte nucleus indirectly in the magnetization of a sensor nucleus. This technique could potentially serve as an encoding module for the recently developed NMR remote detection experiment. The feasibility of using hyperpolarized xenon-129 gas as a sensor is discussed. This work also reports the use of an optical atomic magnetometer to detect the nuclear magnetization of Xe-129 gas, which has potential applicability as a detection module for NMR remote detection experiments.

Urban, Jeffry Todd

2004-12-21

125

Magnetic Criticality and Unconventional Superconductivity in CeCoIn5: Study of 115In-Nuclear Quadrupole Resonance under Pressure  

Microsoft Academic Search

We report the systematic evolution of the superconducting (SC) characteristics of the heavy-fermion (HF) superconductor CeCoIn5 via nuclear-quadrupole-resonance (NQR) measurement under pressure (P). The application of P significantly suppresses the nuclear spin-lattice relaxation rate 1\\/T1 that is dominated by antiferromagnetic (AFM) spin fluctuations (SFs) specific to a quantum critical point (QCP). It is demonstrated that the marked suppression of AFM

M. Yashima; S. Kawasaki; Y. Kawasaki; G.-q. Zheng; Y. Kitaoka; H. Shishido; R. Settai; Y. Haga; Y. Onuki

2004-01-01

126

Superconductivity and Magnetic Fluctuations in Cd2Re2O7 via Cd Nuclear Magnetic Resonance and Re Nuclear Quadrupole Resonance  

NASA Astrophysics Data System (ADS)

We report Cd nuclear magnetic resonance (NMR) and Re nuclear quadrupole resonance (NQR) studies on Cd 2Re2O7, the first superconductor among pyrochlore oxides (Tc~=1 K). The Re NQR spectrum at zero magnetic field below 100 K rules out any magnetic or charge order. The spin-lattice relaxation rate below Tc exhibits a pronounced coherence peak and follows the weak-coupling BCS theory with nearly isotropic energy gap. The results of Cd NMR point to a moderate ferromagnetic enhancement at high temperatures followed by a rapid decrease of the density of states below the structural transition temperature of 200 K.

Vyaselev, O.; Arai, K.; Kobayashi, K.; Yamazaki, J.; Kodama, K.; Takigawa, M.; Hanawa, M.; Hiroi, Z.

2002-06-01

127

A theoretical study of 17O, 14N and 2H nuclear quadrupole coupling tensors in the real crystalline structure of acetaminophen  

NASA Astrophysics Data System (ADS)

A systematic computational investigation was carried out to characterize the 17O, 14N and 2H electric field gradient, EFG, tensors in the acetaminophen real crystalline structure. To include the hydrogen bonding effects in the calculations, the most probable interacting molecules with the target molecule in the crystalline phase were considered through the various molecular clusters. The calculations were performed with the B3LYP method and 6-311++G ?? and 6-311+G ? standard basis sets using the Gaussian 98 suite of programs. Calculated EFG tensors were used to evaluate the 17O, 14N, and 2H nuclear quadrupole resonance, NQR, parameters in acetaminophen crystalline structure, which are in good agreement with the available experimental data. The difference between the calculated NQR parameters of the monomer and molecular clusters shows how much hydrogen bonding interactions affect the EFG tensors of each nucleus. These results indicate that both O-H⋯O and N-H⋯O hydrogen bonding have major influence on the NQR parameters. Moreover, the quantum chemical calculation indicated that the intermolecular hydrogen bonding interactions play an essential role in determining the relative orientation of quadrupole coupling principal components in the molecular frame axes.

Behzadi, Hadi; Esrafili, Mehdi D.; Hadipour, Nasser L.

2007-03-01

128

Temperature dependence of one-dimensional hydrogen bonding in morpholinium hydrogen chloranilate studied by 35Cl nuclear quadrupole resonance and multi-temperature X-ray diffraction.  

PubMed

The temperature dependence of (35)Cl NQR frequencies and the spin-lattice relaxation times T(1) has been measured in the wide temperature range of 4.2-420 K for morpholinium hydrogen chloranilate in which a one-dimensional O-HO hydrogen-bonded molecular chain of hydrogen chloranilate ions is formed. An anomalous temperature dependence of the NQR frequencies was analyzed to deduce a drastic temperature variation of the electronic state of the hydrogen-bonded molecular chain. The hydrogen atom distribution in the OHO hydrogen bond is discussed from the results of NQR as well as multi-temperature X-ray diffraction. Above ca. 330 K, the T(1) showed a steep decrease with an activation energy of ca. 70 kJ mol(-1) and with an isotope ratio (37)Cl T(1)/(35)Cl T(1) = 0.97 ± 0.2. The orientational change of the z axis of electric field gradient tensor in conjunction with the hydrogen transfer between adjacent hydrogen chloranilate ions is suggested as a possible relaxation mechanism. PMID:22872006

Tobu, Yasuhiro; Ikeda, Ryuichi; Nihei, Taka-aki; Gotoh, Kazuma; Ishida, Hiroyuki; Asaji, Tetsuo

2012-09-21

129

Photodarkening effect in glassy As 2S 3 and As 2O 3  

Microsoft Academic Search

Photodarkening, or the shift of the optical absorption edge to smaller energies after excitation with light whose energy is near that of the optical band edge, has been studied in the chalcogenide glasses for many years. Recently we have conducted high field nuclear magnetic resonance (NMR) studies at 17 T and nuclear quadrupole resonance (NQR) studies of 75As in glassy

P. Hari; S. Guzel; T. Su; P. C. Taylor; P. L. Kuhns; W. G. Moulton; N. S. Sullivan

2003-01-01

130

Nuclear magnetic and quadrupole resonance studies of local environments in magnetic and superconducting systems  

NASA Astrophysics Data System (ADS)

Spin-echo nuclear magnetic and quadrupole resonance (NMR/NQR) studies, along with complementary x-ray diffraction and bulk magnetization measurements, have been carried out on the magnetic superconducting system RuSr2RECu 2O8 (RE 1212, RE = Gd or Eu) and systems based on or derived from SrRuO3. In RE1212, two sets of Ru NMR signals are found, indicating the existence of a mixed valence for Ru. This result suggests a hole doping mechanism to account for the superconductivity that originates in the CuO2 planes. The evolution of the Ru NMR spectra in external magnetic fields provides information concerning the magnetic structure of the Ru sublattice which is consistent with the previously proposed type-I antiferromagnetic (AFM) structure. Based on this model, the interplane magnetic coupling and the in-plane spin-flop critical field are determined. While substituting for the Ru-site in SrRuO3, Mn and vacancies suppress the ferromagnetic (FM) ordering temperature drastically. Cr, on the other hand, increases the ordering temperature. The valence states for Mn, Cr, and Ru are determined from the NMR spectra, which, combined with dc magnetization, also provide information with regard to the various magnetic interactions. The hybridization of the Ru 4d and Mn or Cr 3d orbitals is believed to play a key role in the variation of the ordering temperature. Upon cooling, three consecutive and distinct magnetic transitions are observed for Sr2RuGdO6 at T1 = 33 K, T2 = 17, and T3 < 2 K which are attributed to the Ru-Ru, Ru-Gd, and Gd-Gd AFM interactions, respectively. Weak FM is associated with the transition at 17 K. These features point to the unique role played by Gd in this system. Ru NMR spectra, in the presence of an external magnetic field, demonstrate the existence of a FM phase in the AFM matrix which behaves superparamagnetically. These results strongly suggest that, at low temperature, the magnetic ground state of Sr2RuGdO6 involves complex coexistence and competition of different interactions.

Han, Zhaohui

2006-12-01

131

Hydrogen bonding and proton transfer in cocrystals of 4,4'-bipyridyl and organic acids studied using nuclear quadrupole resonance.  

PubMed

Cocrystals of 4,4'-bipyridyl and several carboxylic acids were grown from the methanol solution of the cocrystal formers. Complete (14)N NQR spectra of these cocrystals have been measured using (1)H-(14)N nuclear quadrupole double resonance. The principal values of the quadrupole coupling tensor are calculated from the (14)N NQR frequencies. A large variation in the (14)N quadrupole coupling constant between 1.3 MHz and 4.7 MHz is observed. A very low (14)N quadrupole coupling constant, characteristic for proton transfer O-H···N ? O(-)···H-N(+), is observed in 4,4'-bipyridyl-oxalic acid (1?:?1). In 4,4'-bipyridyl-5-chlorosalycilic acid (1?:?1) the (14)N NQR data show the presence of a short, strong N···H···O hydrogen bond. A correlation of the principal values of the (14)N quadrupole coupling tensor is observed. The correlation is analyzed in the model, where the deformation of the lone pair electron orbital and the change of the population of the ?-electron orbital produce the variation of the (14)N quadrupole coupling tensor in the hydrogen bonded 4,4'-bipyridyl. The temperature variation of the (14)N quadrupole coupling tensor in 4,4'-bipyridyl-5-chlorosalycilic acid (1?:?1) is analyzed. Proton displacement within the N···H···O hydrogen bond and the change of the population of the ?-electron orbital at the two nitrogen positions in a 4,4'-bipyridyl molecule in the temperature interval between 157 K and 323 K are determined. PMID:25052623

Seliger, Janez; Žagar, Veselko

2014-09-14

132

Stark effect of 75As NQR and asymmetric 1H-75As level crossing in paraelectric potassium dihydrogen arsenate  

Microsoft Academic Search

The nuclear quadrupole coupling constant of 75As in paraelectric KH2AsO4 (KDA) increases when an electric field is applied along the c-axis. The very large shift ?(e2Qq\\/2h)\\/?E of 75As is 9.1 kHz\\/kV cm-1 at T = 106°K = Tc + 10°. At room temperature, when the proton NMR frequency exceeds the alpha' frequency of 75As by Deltanu, the proton relaxation rate

D. Gill

1968-01-01

133

Unique Spin Dynamics and Unconventional Superconductivity in the Layered Heavy Fermion Compound CeIrIn5: NQR Evidence  

Microsoft Academic Search

We report measurements of the 115In nuclear spin-lattice relaxation rate ( 1\\/T1) between T = 0.09 and 100 K in the new heavy fermion (HF) compound CeIrIn5. At 0.4<=T<=100 K, 1\\/T1 is strongly T-dependent, which indicates that CeIrIn5 is much more itinerant than known Ce-based HFs. We find that 1\\/T1T, subtracting that for LaIrIn5, follows a \\\\(1T+theta\\\\)3\\/4 variation with theta

G.-Q. Zheng; K. Tanabe; T. Mito; S. Kawasaki; Y. Kitaoka; D. Aoki; Y. Haga; Y. Onuki

2001-01-01

134

C N.M.R. and N N.Q.R. in ferroelectric liquid crystals Polar versus quadrupolar ordering  

Microsoft Academic Search

C nuclear magnetic resonance and N nuclear quadrupole resonance spectra of ferroelectric smectic C*liquid crystals and their non-chiral analogues allow for a microscopic determination of the polar and quadrupolar (or bipolar) biasing of rotation around the long molecular axis as well as for a determination of the anisotropy in the fluctuations of this axis. The results show that the microscopic

R. Blinc; J. Dolinšek; M. Luzar; J. Seliger

1988-01-01

135

Evidence for Unconventional Strong-Coupling Superconductivity in PrOs4Sb12: An Sb Nuclear Quadrupole Resonance Study  

NASA Astrophysics Data System (ADS)

We report Sb-NQR results which evidence a heavy-fermion (HF) behavior and an unconventional superconducting (SC) property in Pr(Os4Sb12 with Tc=1.85 K. The temperature (T) dependence of nuclear-spin-lattice-relaxation rate, 1/T1, and NQR frequency unravel a low-lying crystal-electric-field splitting below T0˜10 K, associated with Pr3+(4f2)-derived ground state. In the SC state, 1/T1 shows neither a coherence peak just below Tc K nor a T3-like power-law behavior observed for anisotropic HF superconductors with the line-node gap. The isotropic energy gap with its size ?/kB=4.8 K seems to open up across Tc below T*˜2.3 K. It is surprising that Pr(Os4Sb12 looks like an isotropic HF superconductor—it may indeed argue for Cooper pairing via quadrupolar fluctuations.

Kotegawa, H.; Yogi, M.; Imamura, Y.; Kawasaki, Y.; Zheng, G.-Q.; Kitaoka, Y.; Ohsaki, S.; Sugawara, H.; Aoki, Y.; Sato, H.

2003-01-01

136

Analysis of nuclear-quadrupole-resonance spectrum of incommensurate phases: The case of bis(4-chlorophenyl) sulfone  

Microsoft Academic Search

In this work, previous experimental studies of the 35Cl nuclear-quadrupole-resonance (NQR) line shape in the incommensurate phase of bis(4-chlorophenyl) sulfone were extended. The broad spectra in the incommensurate phase (IC) were measured using the Fourier transform of the nuclear signal to avoid systematic errors committed in some studies of this compound. The results were interpreted within the framework of the

J. Schneider; C. Schürrer; A. Wolfenson; A. Brunetti

1998-01-01

137

AMERICAN STUDIES &AMERICAN STUDIES &AMERICAN STUDIES & ETHNICITYETHNICITYETHNICITY  

E-print Network

AMERICAN STUDIES &AMERICAN STUDIES &AMERICAN STUDIES & ETHNICITYETHNICITYETHNICITY This major of the United States with a particular emphasis on comparative study of the peoples, cultures, history: Introduction to American Studies and Ethnicity -- Introduction to American studies and ethnic studies. Provides

Krylov, Anna I.

138

Africana Studies Film Studies  

E-print Network

CENTER EVENT OVAL Anthropology Dance Economics Human Rights Studies Physical Education Political Science COURTYARD LEHMAN LAWN Architecture Art History Classics & Ancient Studies Music Philosophy Religion DIANA Computer Science Environmental Science Mathematics Physics & Astronomy Statistics In the event of rain

139

u63Cu and g199Hg NMR in overdoped HgBa2CaCu2O6+delta  

Microsoft Academic Search

We report on u63Cu and g199Hg NMR spectra and nuclear spin-lattice relaxation rate (1\\/T1) measurements, and the Cu NQR spectrum, in HgBa2CaCu2O6+delta powder sample with Tc = 101 K. The results agree with previous NMR studies in the overdoped regime of the cuprates, showing antiferromagnetic correlations and no spin-gap behaviour in the normal state. The Cu quadrupole coupling frequency v63vQ

M.-H. Julien; M. Horvatic; P. Carretta; C. Berthier; Y. Berthier; P. Ségransan; J.-J. Capponi; S. M. Loureiro

1996-01-01

140

A possible effect of spin fluctuations on the electric field gradient in Cu-O layers in high-Tc superconductors  

Microsoft Academic Search

A possible effect of spin fluctuations on the electric field gradient in Cu-O layers in HTCS is studied by the phenomenological antiferromagnetic Fermi-liquid theory of Millis et al. Our theoretical analysis suggests that the coupling between the quadrupole charge density and the spin fluctuations in the two-dimensional 'metallic' Cu-O layers is the origin of the temperature dependence of 63Cu NQR

Lou Ping

1994-01-01

141

63Cu and 199Hg NMR in overdoped HgBa 2CaCu 2O 6+?  

Microsoft Academic Search

We report on 63Cu and 199Hg NMR spectra and nuclear spin-lattice relaxation rate (1\\/T1) measurements, and the Cu NQR spectrum, in HgBa2CaCu2O6+? powder sample with Tc = 101 K. The results agree with previous NMR studies in the overdoped regime of the cuprates, showing antiferromagnetic correlations and no spin-gap behaviour in the normal state. The Cu quadrupole coupling frequency 63?Q

M.-H Julien; M Horvati?; P Carretta; C Berthier; Y Berthier; P Ségransan; S. M Loureiro; J.-J Capponi

1996-01-01

142

Role of bromine in restoring superconductivity in YBa2Cu3Oy  

Microsoft Academic Search

63,65Cu nuclear quadrupole resonance (NQR), 63,65Cu and 79,81Br nuclear magnetic resonance (NMR), and Br K-edge x-ray-absorption fine-structure (XAFS) measurement techniques have been used to study the local structures of Cu and Br in well-characterized samples of deoxygenated and brominated YBa2Cu3Oy (YBCO). The combined results provide a detailed picture of the role of bromine in reoxygenating the YBCO structure and an

D. M. Potrepka; J. I. Budnick; D. B. Fenner; W. A. Hines; M. Balasubramanian; A. R. Moodenbaugh

1999-01-01

143

Optical and Nuclear Spin Spectroscopy in PRASEODYMIUM(3+):LANTHANUM Fluoride by Optical Pumping  

Microsoft Academic Search

A Stark Modulated Optical Pumping (SMOP) technique was used as a sensitive probe of optical hole-burning to study the effects of nuclear spin interactions in Pr ^{3+}:LaF_3. The results of two experiments are reported. In the first experiment, the SMOP technique is applied for optical detection of the NQR spectrum of the Pr^{3+} optical ground state. Frequency and linewidth variations

Lawrence Leroy Wald

1992-01-01

144

Short-range orientational correlation in the disordered crystal of 1-chloro-4-iodobenzene  

Microsoft Academic Search

p-chlorobromobenzene (PCBB) and p-chloroiodobenzene (PCIB) crystallize in the centrosymmetric space group P21\\/c, Z=2. Since the molecules do not possess an inversion center, the crystals exhibit orientational disorder, in other words, the electrical dipoles of regularly distributed molecules irregularly point in opposite directions. In this study, the temperature dependence of the nuclear quadrupole resonance (NQR) line shape for PCBB and PCIB

C. A. Meriles; S. C. Pérez; A. E. Wolfenson; A. H. Brunetti

1999-01-01

145

Short-range orientational correlation in the disordered crystal of 1-chloro-4-iodobenzene  

Microsoft Academic Search

p-chlorobromobenzene (PCBB) and p-chloroiodobenzene (PCIB) crystallize in the centrosymmetric space group P21\\/c,Z=2. Since the molecules do not possess an inversion center, the crystals exhibit orientational disorder, in other words, the electrical dipoles of regularly distributed molecules irregularly point in opposite directions. In this study, the temperature dependence of the nuclear quadrupole resonance (NQR) line shape for PCBB and PCIB and

C. A. Meriles; S. C. Pe´rez; A. E. Wolfenson; A. H. Brunetti

1999-01-01

146

Non-cyclic geometric phase of nuclear quadrupole resonance signals of powdered samples.  

PubMed

The non-cyclic geometric phase of ¹?N and ³?Cl NQR signals induced by the character of trajectory of nuclear magnetization motion upon pulse r.f. excitation of powdered samples is studied. Analytical expressions for the geometric phases of NQR signals of the nuclei of spins I=1 and 3/2 upon nuclear magnetization rotation induced by means of r.f. pulses with frequency detuned from the resonance and for any impulse duration for a separate crystallite are obtained. It is shown that the geometric phase recorded for the signal from a powdered sample at ??=0 can be different from zero and can oscillate upon changes in duration of the r.f. excitation pulse. An alternative variant of the nutation experiment aimed at obtaining the asymmetry parameter ? from locations of frequency singularities in the nutation phase spectrum for nuclei of spin I=3/2 in powder substances is proposed. PMID:21463929

Glotova, O; Ponamareva, N; Sinyavsky, N; Nogaj, B

2011-01-01

147

Thermodynamic contribution to the regulation of electron transfer in the Na(+)-pumping NADH:quinone oxidoreductase from Vibrio cholerae.  

PubMed

The Na(+)-pumping NADH:quinone oxidoreductase (Na(+)-NQR) is a fundamental enzyme of the oxidative phosphorylation metabolism and ionic homeostasis in several pathogenic and marine bacteria. To understand the mechanism that couples electron transfer with sodium translocation in Na(+)-NQR, the ion dependence of the redox potential of the individual cofactors was studied using a spectroelectrochemical approach. The redox potential of one of the FMN cofactors increased 90 mV in the presence of Na(+) or Li(+), compared to the redox potentials measured in the presence of other cations that are not transported by the enzyme, such as K(+), Rb(+), and NH(4)(+). This shift in redox potential of one FMN confirms the crucial role of the FMN anionic radicals in the Na(+) pumping mechanism and demonstrates that the control of the electron transfer rate has both kinetic (via conformational changes) and thermodynamic components. PMID:22533880

Neehaul, Yashvin; Juárez, Oscar; Barquera, Blanca; Hellwig, Petra

2012-05-15

148

ATBC Study - Study Details  

Cancer.gov

The Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study was conducted in Finland as a joint project between the National Institute for Health and Welfare of Finland and the US National Cancer Institute (NCI) . The overall design, rationale, objectives, and initial results of this intervention study have been published1,2. Briefly, this was a randomized, double-blind, placebo-controlled, primary prevention trial to determine whether daily supplementation with alpha-tocopherol, beta-carotene, or both would reduce the incidence of lung or other cancers among male smokers.

149

Microscopic study of local structure and charge distribution in metallic La{sub 2}CuO{sub 4+{delta}}  

SciTech Connect

The authors employ NMR and NQR spectroscopy as probes of local structure and charge environments in metallic La{sub 2}CuO{sub 4+{delta}} ({Tc} = 38 K). They discuss the effect of annealing the sample at various temperatures T{sub a} ({Tc} < T{sub a} < 300K) on the superconducting {Tc}. The dependence of {Tc} on annealing indicates that annealing allows the development of structural order which is important for {Tc}. The {sup 139}La quadrupole frequency, {nu}{sub Q} is smaller than in undoped materials. This is unexpected and may indicate a smaller charge on the apex oxygen in the doped material and thus a different distribution of charge between the La-O layer to the planes. The further, rapid decrease in {nu}{sub Q} just above {Tc} indicates that temperature dependent charge redistribution is occurring. The presence of doped holes induces a distribution of displacements of the apex oxygen off of the vertical La-Cu bond axis. These vary from zero to the value observed in lightly doped (antiferromagnetic) La{sub 2}CuO{sub 4+{delta}}. These measurements demonstrate a striking degree of inhomogeneity in the crystal structure of the La-O layer. Copper NQR spectroscopy shows that there are two distinct copper sites in the CuO{sub 2} planes and thus that either the structure or the charge distribution in the planes is inhomogeneous as well. These inhomogeneities are the intrinsic response of the crystal to doped holes; they are not the result of distortions of the lattice due to the presence of interstitial oxygen atoms.

Hammel, P.C.; Reyes, A.P.; Ahrens, E.T.; Fisk, Z.; Canfield, P.C.; Thompson, J.D. [Los Alamos National Lab., NM (United States); Schirber, J.E. [Sandia National Labs., Albuquerque, NM (United States)

1993-10-29

150

Nuclear quadrupole resonance studies of transparent conducting oxides.  

PubMed

We report (63,65)Cu spin-lattice relaxation rates measured by nuclear quadrupole resonance (NQR) in the delafossite compound CuYO(2) and CuYO(2):Ca over a temperature range from 200 to 450K. CuYO(2):Ca is a prototype transparent oxide exhibiting p-type electrical conductivity. Relaxation rates in CuYO(2):Ca are enhanced by one to two orders of magnitude relative to undoped material, exhibit much stronger temperature dependence, and contain contributions from magnetic and quadrupolar relaxation mechanisms with roughly equal strengths. Relaxation in undoped CuYO(2) is of purely quadrupolar origin and is attributed to interactions with lattice phonons. The main focus of this paper is the magnetic contribution to the relaxation rate in CuYO(2):Ca which is attributed to the hyperfine fields of carriers. It is argued that the dynamics of the hyperfine field are dominated by the hopping rate for carrier transfers between neighboring atoms in the copper planes of the delafossite structure. Comparison of the magnetic relaxation rates with the DC conductivity permits an estimate of the carrier concentration and mobility. PMID:15388186

Warren, W W; Rajabzadeh, A; Olheiser, T; Liu, J; Tate, J; Jayaraj, M K; Vanaja, K A

2004-01-01

151

Improving the sensitivity of a high-Tc SQUID at MHz frequency using a normal metal transformer  

Microsoft Academic Search

Superconducting quantum interference devices (SQUIDs) can be used to detect the signals of nuclear quadrupole resonance (NQR). The NQR frequencies of some interesting materials are in the order of MHz. However, the sensitivity of a high-Tc SQUID is normally not enough to detect the weak NQR signals. To improve the sensitivity of a high-Tc SQUID at MHz frequency, we used

D. F. He; H. Itozaki; M. Tachiki

2006-01-01

152

American studies Why American studies?  

E-print Network

American studies Why American studies? The US is the sole superpower in the 21st century and its may live. Studying American history, culture and society in the context of the Americas provides much What American studies courses are there? American Studies American Studies and English American Studies

Sussex, University of

153

1 Africana Studies AFRICANA STUDIES  

E-print Network

1 Africana Studies AFRICANA STUDIES GW's Africana Studies Program promotes an interdepartmental, interdisciplinary course of study examining the diverse histories, cultures, politics and people of the African's course of study might range from a study of Caribbean cultures, the literature of Black America

Vertes, Akos

154

Comparative Ethnic Studies Latino Studies  

E-print Network

0 Comparative Ethnic Studies Latino Studies Asian American Studies Indigenous/Native American Studies CSER Student Guide 2012-13 Ethnicity & Race Center for the Study of #12;1 About CSER Founded in 1999, the Center for the Study of Ethnicity and Race (CSER) is a vibrant teaching, research

Qian, Ning

155

1 Peace Studies PEACE STUDIES  

E-print Network

1 Peace Studies PEACE STUDIES The peace studies program encourages students to explore the multiple, and environmental justice. The peace studies program focuses on the study of peace and conflict through the lens.columbian.gwu.edu) in the Columbian College, the peace studies program emphasizes the role of world religions in peace building

Vertes, Akos

156

Sb-NQR probe for superconducting properties in the Pr-based filled-skutterudite compound PrRu4Sb12  

Microsoft Academic Search

We report the electronic and superconducting properties in the Pr-based filled-skutterudite superconductor PrRu4Sb12 with Tc=1.3 K via the measurements of nuclear-quadrupole-resonance frequency nuQ and nuclear-spin-lattice-relaxation time T1 of Sb nuclei. The temperature dependence of nuQ has revealed the energy scheme of Pr3+ crystal electric field that is consistent with an energy separation DeltaCEF˜70 K between the ground state and the

M. Yogi; H. Kotegawa; Y. Imamura; G.-Q. Zheng; Y. Kitaoka; H. Sugawara; H. Sato

2003-01-01

157

Magnetic Criticality and Unconventional Superconductivity in CeCoIn5: Study of 115In-Nuclear Quadrupole Resonance under Pressure  

NASA Astrophysics Data System (ADS)

We report the systematic evolution of the superconducting (SC) characteristics of the heavy-fermion (HF) superconductor CeCoIn5 via nuclear-quadrupole-resonance (NQR) measurement under pressure (P). The application of P significantly suppresses the nuclear spin-lattice relaxation rate 1/T1 that is dominated by antiferromagnetic (AFM) spin fluctuations (SFs) specific to a quantum critical point (QCP). It is demonstrated that the marked suppression of AFM SFs leads to a reduction in the SC energy gap or in the coupling strength of the Cooper pair. Tc, nevertheless, increases with increasing P due to the increase in HF bandwidth. This is expected to make the lifetime of quasi-particles sufficiently long.

Yashima, M.; Kawasaki, S.; Kawasaki, Y.; Zheng, G.-q.; Kitaoka, Y.; Shishido, H.; Settai, R.; Haga, Y.; ?nuki, Y.

2004-08-01

158

USF Graduate Studies Cultural Studies  

E-print Network

Humanities USF Graduate Studies Cultural Studies and The Master of Arts in American Studies offers) is an interdisciplinary, interdepartmental program that offers students an opportunity to study the ideas and works that have - The MLA in Humanities track offers an interdisciplinary approach to the study of European

Meyers, Steven D.

159

1 Women's Studies WOMEN'S STUDIES  

E-print Network

1 Women's Studies WOMEN'S STUDIES Students gain knowledge of contemporary feminist theories of the Columbian College of Arts and Sciences' arts and humanities programs, women's studies examines women's lives's programs · Bachelor of Arts with a major in women's studies (http:// bulletin.gwu.edu/arts-sciences/womens-studies

Vertes, Akos

160

Nursing Studies Nursing Studies highlights  

E-print Network

Nursing Studies Nursing Studies highlights Autumn 2013 #12;Nursing Studies The University by the validation panel as `leading edge'. Nursing Studies at the University of Edinburgh has enjoyed another consecutive year, the Bachelor of Nursing with Honours programme achieved the top place in the Guardian's UK

Edinburgh, University of

161

1 Museum Studies MUSEUM STUDIES  

E-print Network

as they relate to organizational change efforts. Case studies of museums undergoing change; best practices1 Museum Studies MUSEUM STUDIES Overview Columbian College of Arts and Sciences offers an interdepartmental program leading to the degree of Master of Arts in the field of museum studies. The program

Vertes, Akos

162

1 Judaic Studies JUDAIC STUDIES  

E-print Network

1 Judaic Studies JUDAIC STUDIES The Columbian College of Arts and Sciences offers an interdisciplinary program in Judaic Studies leading to the degree of Bachelor of Arts. The program, whose purview. The Program in Judaic Studies also provides students with the opportunity to interact with their professors

Vertes, Akos

163

Studying Genes  

MedlinePLUS

NIGMS Home > Science Education > Studying Genes Studying Genes Tagline (Optional) Middle/Main Content Area What are genes? Genes are sections of DNA that contain instructions for making the molecules—many of ...

164

Intelligence Studies  

ERIC Educational Resources Information Center

To make an academic study of matters inherently secret and potentially explosive seems a tall task. But a growing number of scholars are drawn to understanding spycraft. The interdisciplinary field of intelligence studies is mushrooming, as scholars trained in history, international studies, and political science examine such subjects as the…

Monaghan, Peter

2009-01-01

165

Social Studies.  

ERIC Educational Resources Information Center

The product of a Special Studies Institute, this teacher developed resource guide for the emotionally handicapped (K-6) presents social study concepts and activities relative to education in the urban out-of-doors. Focus is on the study of man (past, present, and future) interacting with his environment. Listed below are activity examples: (1)…

Bieber, Edward

166

Religious Studies.  

ERIC Educational Resources Information Center

An essay on the study of religion at the college level and descriptions of nine programs of religious studies are presented. The essay by David C. Smith suggests that while traditional goals continue to be important, especially in church-related colleges, religious studies has expanded to include insights and materials from such disciplines as…

Mohrman, Kathryn, Ed.

1980-01-01

167

1 Film Studies FILM STUDIES  

E-print Network

1 Film Studies FILM STUDIES Housed in the Columbian College of Arts and Sciences, the Film Studies Program covers classical film aesthetics, surveys the history of world cinema and takes an in-depth look at films from America, France, Germany, Japan, Russia and the Hispanic world. UNDERGRADUATE Minor · Minor

Vertes, Akos

168

Film Studies 121 Film Studies  

E-print Network

Film Studies · 121 Film Studies ADVISORY COMMITTEE: Lowry (Director, English), Stock (Modern Languages), Stock (Mod- ern Languages), Stoddard (Education), Zuber (English). The minor in Film Studies-is per- haps the predominant way that World cultures represent themselves. Film has become

Lewis, Robert Michael

169

Studying Abroad  

NSDL National Science Digital Library

Recently unveiled by UNESCO, this site is designed to serve as a resource for students considering studying abroad at institutions of higher education, university community members, Secretariats of Regional Committees, and other interested parties. At present, much of the site is under construction, but it does offer an electronic version of Study Abroad, UNESCO's massive guide to higher-education study opportunities and scholarships. The guide totals 629 pages and includes 2,659 entries on courses and scholarships in different higher-education academic and professional disciplines in 129 countries. Anyone interested in studying abroad will want to take a look at this guide and monitor the site for future developments.

2001-01-01

170

Social Studies.  

ERIC Educational Resources Information Center

This document contains the following papers on social studies instruction and technology: (1) "Waking the Sleeping Giant: Social Studies Teacher Educators Collaborate To Integrate Technology into Methods' Courses" (Cheryl Mason, Marsha Alibrandi, Michael Berson, Kara Dawson, Rich Diem, Tony Dralle, David Hicks, Tim Keiper, and John Lee); (2)…

White, Cam, Ed.

171

Stream Study  

NSDL National Science Digital Library

The Stream Study provides a method to determine the water quality of a stream based on the collection and identification of stream-bottom macroinvertebrates. The site includes a catalog of common stream macroinvertebrates and a glossary of terms used to study streams.

Glenn Bull

1999-03-01

172

Studying Zooarchaeology  

ERIC Educational Resources Information Center

Children often associate the study of bones with dinosaurs or crime scenes. This unit introduces students to "zooarchaeology," the study of animal remains from archaeological sites. Students in grades 3-5 engage in hands-on activities examining bones, shells, and other "hard parts" of animals. They use their observations as a starting point for…

Moore, Molly; Wolf, Deborah; Butler, Virginia L.

2012-01-01

173

Peace Studies.  

ERIC Educational Resources Information Center

Selected college peace studies programs are described, and perspectives on such efforts in higher education are considered in an article by Robert C. Williams, "Sounds of Silence: The Academy and the Nuclear Question." Following the essay, peace studies activities of six colleges are described. At Syracuse University, the Program in Nonviolent…

Brown, Peggy, Ed.

1983-01-01

174

African Studies  

NSDL National Science Digital Library

The African Studies WWW server contains information on programs and resources at the University of Pennsylvania, in Africa, the U.S. and elsewhere. The web site is supported by the African Studies Center, part of a four-school consortium, including Bryn Mawr, Haverford, and Swarthmore Colleges and the University of Pennsylvania.

175

Observational Studies  

NSDL National Science Digital Library

This lesson on observational studies discusses the nature of such studies, the relationships between various data sets, and regression. Graphs illustrate the relationships, and exercises at the end test the user's comprehension and understanding. It is taken from the online textbook for Western Michigan University online introductory stats course.

Abebe, Asheber; Daniels, John E.; Kapenga, J. A.; Mckean, Joe W.

2008-12-25

176

Russian studies  

NSDL National Science Digital Library

College and Research Library News has posted this new annotated directory to aid students and researchers working in Russian studies. This site casts a wide net over English and Cyrillic sites in Russian studies, offering a sampling of search engines, news media, meta-indexes, online publications, academic research, and subject-specific sites, just to name a few.

177

173Environmental Studies ENVIRONMENTAL STUDIES  

E-print Network

173Environmental Studies ENVIRONMENTAL STUDIES (ENV) CORE fACULTy: ProfESSorS KAhN*, CooPEr, WArrEN ASSoCIATE ProfESSorS DrUMBL, KNAPP ASSISTANT ProfESSorS CASEY, HAMILToN The Program in Environmental world community. The Program in Environmental Studies is not a ma- jor, but rather a series of related

Dresden, Gregory

178

Cholera studies  

PubMed Central

In this study, the author describes in detail experimental cholera infection of mammals (infection by the oral route, intragastric inoculation, and intestinal, gall-bladder, and parenteral infection). The pathogenicity for lower animals is examined, and certain observations on insects are included. The second part of the study is devoted to the pathology of human cholera (morbid anatomy distribution of the causative organisms in the dead bodies of cholera victims, and pathogenesis). PMID:13284569

Pollitzer, R.

1955-01-01

179

Sister Study  

Cancer.gov

The Sister Study, conducted by the National Institute of Environmental Health Sciences (NIEHS), is prospectively examining environmental and familial risk factors for breast cancer and other outcomes in a cohort of 50,884 sisters of women who have had breast cancer. These sisters have about twice the risk of developing breast cancer due to their family history and are expected to be highly motivated to participate in a long-term study.

180

Structure of the V. cholerae Na+-pumping NADH:quinone oxidoreductase.  

PubMed

NADH oxidation in the respiratory chain is coupled to ion translocation across the membrane to build up an electrochemical gradient. The sodium-translocating NADH:quinone oxidoreductase (Na(+)-NQR), a membrane protein complex widespread among pathogenic bacteria, consists of six subunits, NqrA, B, C, D, E and F. To our knowledge, no structural information on the Na(+)-NQR complex has been available until now. Here we present the crystal structure of the Na(+)-NQR complex at 3.5 Å resolution. The arrangement of cofactors both at the cytoplasmic and the periplasmic side of the complex, together with a hitherto unknown iron centre in the midst of the membrane-embedded part, reveals an electron transfer pathway from the NADH-oxidizing cytoplasmic NqrF subunit across the membrane to the periplasmic NqrC, and back to the quinone reduction site on NqrA located in the cytoplasm. A sodium channel was localized in subunit NqrB, which represents the largest membrane subunit of the Na(+)-NQR and is structurally related to urea and ammonia transporters. On the basis of the structure we propose a mechanism of redox-driven Na(+) translocation where the change in redox state of the flavin mononucleotide cofactor in NqrB triggers the transport of Na(+) through the observed channel. PMID:25471880

Steuber, Julia; Vohl, Georg; Casutt, Marco S; Vorburger, Thomas; Diederichs, Kay; Fritz, Günter

2014-12-01

181

Case Studies  

ERIC Educational Resources Information Center

This article presents two case studies using online surveys for evaluation. The authors begin with an example of a needs assessment survey designed to measure the amount of help new students at a university require in their first year. They then discuss the follow-up survey conducted by the same university to measure the effectiveness of the…

Ritter, Lois A., Ed.; Sue, Valerie M., Ed.

2007-01-01

182

Research Study  

ERIC Educational Resources Information Center

Background: Action Research about my 2nd grade classroom in the Buffalo School District. I examined three areas of interest and tried to find some conclusions related to behavior management. Purpose: The purpose of this study is how will implementing procedures, rules, and consequences help improve student behavior. Research Design: Descriptive;…

Glick, Ashley

2010-01-01

183

Proton dynamics in one-dimensional hydrogen-bonding system in molecular co-crystals TMP-D2ca and DMP-H2ca  

NASA Astrophysics Data System (ADS)

The proton dynamics in one-dimensional hydrogen-bonding system in molecular co-crystals of tetramethylpyrazine (TMP) with chloranilic acid (H2ca), as well as 2,6-dimethylpyrazine (DMP) with H2ca is studied by 35Cl NQR and 2H NMR spin-lattice relaxation measurements. No transfer motion of proton between the acid and base molecules is observed in DMP-H2ca, while the motion of the acid proton is excited in TMP-H2ca and the activation energy for the motion increases from 35 kJ mol - 1 to 50 kJ mol - 1 by the deuteration.

Asaji, T.; Amino, D.; Tago, N.; Mizuno, M.

2010-04-01

184

Nuclear quadrupole resonance: a technique to control hydration processes in the pharmaceutical industry.  

PubMed

Pharmaceuticals can exist in many solid forms, which can have different physical and chemical properties. These solid forms include polymorphs, solvates, amorphous, and hydrates. Particularly, hydration process can be quite common since pharmaceutical solids can be in contact with water during manufacturing process and can also be exposed to water during storage. In the present work, it is proved that NQR technique is capable of detecting different hydrated forms not only in the pure raw material but also in the final product (tablets), being in this way a useful technique for quality control. This technique was also used to study the dehydration process from pentahydrate to trihydrate. PMID:21314133

Limandri, Silvina; Visñovezky, Claudia; Pérez, Silvina C; Schurrer, Clemar A; Wolfenson, Alberto E; Ferro, Maribel; Cuffini, Silvia L; de Souza, Joel Gonçalves; Aguiar, F Armani; de Gaitani, C Masetto

2011-03-01

185

Is the pseudogap a topological state?  

NASA Astrophysics Data System (ADS)

We conjecture that the pseudogap is an inhomogeneous condensate above the homogeneous state whose existence is granted by topological stability. We consider the simplest possible order parameter theory that provides this interpretation of the pseudogap and study its angular momentum states. Also we obtain a solution of the Bogomol'nyi self-duality equations and find skyrmions. The normal state gap density, the breaking of the time reversal symmetry and the checkerboard pattern are naturally explained under this view. The pseudogap is a lattice of skyrmions and the inner weak local magnetic field falls below the experimental threshold of observation given by NMR/NQR and ?SR experiments.

Vargas-Paredes, Alfredo A.; Cariglia, Marco; Doria, Mauro M.

2015-02-01

186

Study effectively.  

PubMed

As a busy healthcare practitioner with a desire to maintain and update professional skills and knowledge, perhaps the study skills you acquired as an undergraduate may need to be updated and refined too. Issues of time management take on a different meaning with the increased pressures of juggling a busy career, home life and continuing professional development. As an undergraduate, your focus was very much on learning the volume of material that was delivered in the medical curriculum but was the idea of learning how to learn ever considered? This article is aimed at identifying some of the strategies that might be helpful in enabling you to make the most effective use of the time available to you for study and thereby ensuring that your learning opportunities are maximised. PMID:19583907

Pugsley, Lesley

2009-05-01

187

OPEN Study  

Cancer.gov

Over the course of the study, OPEN participants completed 2 Food Frequency Questionnaires (FFQ), 2 24-recall interviews, and filled out several other health-related questionnaires. They were dosed with doubly labeled water (a biomarker used for measuring energy expenditure), provided several spot urine samples to complete the doubly labeled water assessment, completed two 24-hour urine collections and had their height and weight measured.

188

Retrospective studies.  

PubMed

Large retrospective, epidemiological studies accumulated in the late 1980s, providing increasing evidence to the deeply rooted thought that perinatal events could persistently affect the individual's functioning and health/disease patterns throughout the lifetime. Evidences of such associations can be found in the literature since the beginning of the twentieth century, but studies from Barker, Hales, and colleagues serve as an important hallmark. They proposed the "thrifty phenotype" hypothesis, stating that poor nutrition in fetal and early infant life is detrimental to the development and function of the individuals' organism, predisposing them to the later development of adult chronic diseases. At first used to explain the increased risk for type 2 diabetes in low birth weight individuals, the hypothesis was soon adapted to other systems, becoming one of the core assumptions of the Developmental Origins of Adult Health and Disease (DOHaD) model. The central nervous system is also vulnerable to the effects of environmental variation during fetal or neonatal life. Many researchers have explored the effects of perinatal programming on the human neurodevelopment, and some aspects of the brain structure and/or functioning (such as cognitive function, physiological reactivity to stress, and the risk for behavioral disorders or psychopathology) were shown to be modifiable by the exposure to certain adverse events early in life such as neonatal infections, exposure to gestational psychosocial stress, nutrition during gestation, exposure to drugs, or tobacco smoking during pregnancy. Until recently, most studies focused on birth weight as a strong surrogate of the intrauterine environment, investigating the effects of low birth weight (as a marker of suboptimal fetal environment) on a variety of neurodevelopmental outcomes. Despite the fact that literature reviews on this topic are as old as 1940, the more recent retrospective studies are summarized in this chapter. PMID:25287544

Silveira, Patrícia Pelufo; Manfro, Gisele Gus

2015-01-01

189

Electrophysiologic Study  

PubMed Central

Studies have shown the predictive value of inducible ventricular tachycardia and clinical arrhythmia in patients who have structural heart disease. We examined the possible predictive value of electrophysiologic study before the placement of an implantable cardioverter-defibrillator. Our retrospective study group comprised 315 patients who had ventricular tachycardia that was inducible during electrophysiologic study and who had undergone at least 1 month of follow-up (247 men; mean age, 66.9 ± 13.5 yr; mean follow-up, 24.9 ± 14.8 mo). Recorded characteristics included induced ventricular tachycardia cycle length, atrio-His and His-ventricular electrograms, PR and QT intervals, QRS duration, and drug therapy. Of the 315 patients, 97 experienced ventricular arrhythmia during the follow-up period, as registered by 184 of more than 400 interrogations. There were 187 episodes of ventricular arrhythmia (tachycardia, 178; fibrillation, 9) during 652.5 person-years of follow-up. Subjects with a cycle length ?240 msec were more likely to have an earlier 1st arrhythmia than those with a cycle length <240 msec (P=0.032). A quarter of the subjects with a cycle length ?240 msec had their 1st arrhythmia by 19.14 months, compared with 23.8 months for a quarter of the subjects with a cycle length <240 msec (P <0.032). Among the electrophysiologic characteristics examined, inducible ventricular tachycardia with a cycle length ?240 msec is predictive of appropriate implantable cardioverter-defibrillator therapy at an earlier time. This may have prognostic implications that warrant implantable cardioverter-defibrillator programming to enable appropriate antitachycardia pacing in this group of patients. PMID:20548804

Gold, Daniel R.; Catanzaro, John N.; Makaryus, John N.; Waldman, Cory; Sauer, William H.; Sison, Cristina; Makaryus, Amgad N.; Altman, Erik; Jadonath, Ram; Beldner, Stuart

2010-01-01

190

Leukokinetic studies  

PubMed Central

The mechanism by which adrenocortical steroids induce granulocytosis in man has been investigated using granulocytes labeled with radioactive diisopropylfluorophosphate. After an intravenous injection of 200 mg of cortisol was given to five normal subjects, the mean value for the total blood granulocyte pool increased from 79 to 138 × 107 cells per kg of body weight and reflected an increase in the size of both the circulating granulocyte pool and the marginal granulocyte pool. When granulocytes in the circulation were labeled with diisopropylfluorophosphate and granulocytosis was induced later by the intravenous administration of cortisol, the rate of decline of granulocyte specific activity was increased, indicating that the blood pool was being diluted at an accelerated rate by unlabeled cells entering from the bone marrow. The rate of egress of granulocytes from the blood pool to an inflammatory exudate was studied by the “skin window” technique. After the administration of cortisol, there was a mean reduction in the cellularity of induced inflammatory exudates of 75%. However, this reduction in cellularity varied considerably from subject to subject (45-98%). From these studies we can infer that steroids induce an absolute granulocytosis by decreasing the rate of egress of cells from the total blood granulocyte pool as well as by increasing the influx of cells from the bone marrow. By model simulation studies of the non-steady state induced by cortisol injection, it has been possible to quantitate these rate changes. In the present studies cortisol injection resulted in a mean decrease in blood granulocyte egress of 74% (1-99%) and a mean increase in cell inflow of 450% (300-750%). PMID:5638121

Bishop, C. R.; Athens, J. W.; Boggs, D. R.; Warner, H. R.; Cartwright, G. E.; Wintrobe, M. M.

1968-01-01

191

Anticorrosion studies  

NASA Technical Reports Server (NTRS)

The aging behavior of chemically bonded interfaces between metals and pottants, such as ethylene vinyl acetate (EVA) was studied using the Dow Corning primer systems. It was observed that the primers seem to function as anticorrosive agents on metal surfaces. It was demonstrated that EVA, and the A-11861 EVA/glass primer stops corrosion of the aluminum used on the back surfaces of crystalline silicon solar cells. However, this same treatment does not work for the aluminum on the back surfaces of amorphous silicon solar cells.

Boerio, J.

1986-01-01

192

Anticorrosion studies  

NASA Astrophysics Data System (ADS)

The aging behavior of chemically bonded interfaces between metals and pottants, such as ethylene vinyl acetate (EVA) was studied using the Dow Corning primer systems. It was observed that the primers seem to function as anticorrosive agents on metal surfaces. It was demonstrated that EVA, and the A-11861 EVA/glass primer stops corrosion of the aluminum used on the back surfaces of crystalline silicon solar cells. However, this same treatment does not work for the aluminum on the back surfaces of amorphous silicon solar cells.

Boerio, J.

193

Quaternary Studies  

NSDL National Science Digital Library

First, the Irish Quaternary Association (IQUA) website publicizes its aim "to promote Quaternary studies in Ireland through its publications, and the organization of field meetings and conferences" (1). Visitors can learn about the importance of quaternary studies as well as find out the latest news and upcoming meetings. At the second website, the University of Wisconsin-Madison describes the current and recent studies dealing with "basic and applied problems in glacial geology, surficial geology, palynology, sedimentology, geologic mapping, hydrogeology, soils, and environmental geology "(2). The website offers abstracts of publications of members of the Department of Geology and Geophysics and the Wisconsin Geological and Natural History Survey along with descriptions of the lab, a shaded relief map of the Wisconsin area, and amusing glacial songs. Next, the Godwin Institute of Quaternary Research (GIQR) presents the University of Cambridge's history in quaternary research and the seven current research groups and four recent research projects (3 ). The website furnishes news from the research groups, a gallery of historical images of the East Anglia excursion, and summaries of the Institute's reference collections. Fourth, the International Union for Quaternary Research (INQUA) discusses quaternary scientists' investigations "to interpret the changing world of the glacial ages and their impact on our planet's surface environments" (4). Researchers can find out about INQUA-funded projects, meetings, and scientific commissions. Next, the Quaternary Research Association explains that it "exists to promote understanding of the Quaternary Period by publishing field guides, technical guides, and an international journal as well as holding field meetings and speaker meetings" (5). Students and researchers can discover employment, research, grant, meetings, and educational opportunities. Sixth, the University of Wales presents its investigations in the Remote Sensing Laboratory, Palaeoecology Laboratory, and the Luminescence Laboratory (6 ). Users can find concise descriptions of individual researchers' successes, abstracts of published papers, and links to conference information. The seventh website illustrates the Alaska Quaternary Center's commitment "to the promotion of interdisciplinary research and the enhancement of interdisciplinary instruction in Quaternary sciences" (7). Users can view images of the field work and learn how to obtain quaternary data from the Geographic Information Network of Alaska (GINA). Lastly, Rutgers University promotes its Graduate Certificate in Quaternary Studies where students take part in geology, geography, meteorology, and other disciplines interested in the last couple of million years of Earth's history (8). Students and educators can find information on the researchers involved with the program and the necessary course work.

194

Nutritional studies  

NASA Technical Reports Server (NTRS)

Detailed metabolic studies were conducted of the Apollo 16 and Apollo 17 flight crews, and the results are presented in tabular form. Intake and absorption data are also included. Apollo nutrient intakes were found to be characteristically hypocaloric. Estimates of body composition changes from metabolic balance data, from preflight and postflight weights and volumes, and from total body water and potassium provide no evidence for diminished caloric requirements during a flight. As observed during the Gemini Program and during periods of bed rest, measurements of bone density and metabolic balance confirm a tendency toward loss of skeletal tissue in weightlessness. No evidence exists that any inflight metabolic anomaly, including hypokalemia, was induced by marginal or deficient nutrient intakes. In general, the Apollo crewmen were well nourished and exhibited normal gastroenterological functions, although appetite was somewhat diminished and the organoleptic response to food was somewhat modified during flight.

Rambaut, P. C.; Smith, M. C., Jr.; Wheeler, H. O.

1975-01-01

195

Cholera studies*  

PubMed Central

The first section of this study deals with areas where cholera is endemic and with the conditions normally favouring endemicity. Turning next to epidemics, the author discusses their origin and types, climatic influences on them, their periodicity and the possibility of forecasting them, the role played in them by different serological races of V. cholerae, and the causes of their decline. In a section on the factors governing the local spread of cholera, he considers contact and water-borne infection; the role of contaminated food and drink, of fomites, of flies, and of carriers; and the incidence according to sex, age, race, and occupation. The last part deals with factors governing the spread of cholera over longer distances, and includes discussion of the effect of movements of individuals and groups and of assemblies of the population on pilgrimages or at religious festivals. PMID:13472431

Pollitzer, R.

1957-01-01

196

Plague studies*  

PubMed Central

Epidemiological aspects of (a) bubonic plague and (b) primary pneumonic plague are discussed separately in this study. The cause, spread, and persistence of bubonic outbreaks are dealt with. In the case of primary pneumonic plague, the author systematically reviews the factors influencing the spread of the disease: climatic and social conditions, infectivity of the patients, immunity, and control measures. In discussing the cause of pneumonic plague outbreaks, the author deals with the possible influence of a special virulence of pneumonic strains, the role of the rodent and flea species involved, and the possibility of a pneumotropismus acquired by Pasteurella pestis. The periodicity (cyclical and secular) of bubonic plague epidemics is discussed with a view to the possible forecasting of future epidemics. The author indicates the influence of race, age, sex, and occupation on the incidence of both forms of the disease. PMID:13082391

Pollitzer, R.

1953-01-01

197

Plague studies*  

PubMed Central

The author examines in detail the symptomatology, diagnosis, and treatment of plague, and outlines the problem of the length of the incubation period. The clinical features commonly met with in all severely-affected plague patients, regardless of the primary localization of the infection, are described. The author then deals with the symptomatology and manifestations of bubonic plague as compared to those of primary pneumonic plague. The importance of a clinical diagnosis, from the point of view of prevention, is stressed, and the differential diagnosis of various forms of the disease is described. The study contains a detailed discussion of the respective merits of antibiotic treatment, serotherapy, and sulfonamide treatment. The author points out that the outstanding success of streptomycin and some other antibiotics will probably relegate the sulfonamides to the second rank in the treatment of bubonic plague. PMID:13082390

Pollitzer, R.

1953-01-01

198

Heavy-fermion like behavior of amorphous CexMn100-x alloys system studied by 55Mn NMR  

NASA Astrophysics Data System (ADS)

In order to investigate a heavy-fermion like behavior on Ce-rich side of amorphous CexMn100-x alloys system, the 55Mn NMR measurements on the powdered sample of amorphous Ce62Y19Mn19, being diluted with non-magnetic Y, have been carried out in the temperature range from 1.8 to 270 K. A broadened resonance spectrum containing five NQR lines is observed in the measuring temperature region. Temperature dependences of Quadrupole coupling constant (e2Qq) and the line width of 55Mn NMR are obtained by means of analysis of each spectrum. Temperature dependence of the line width is expressed by the Curie-Weiss law with Tc = -12.0 K. The 1/(T1T) is rapidly increased in proportion to inverse square root of temperature with decreasing temperature, but it keeps almost constant below about 6 K, which shows the heavy-fermion state in Ce62Y19Mn19.

Niki, H.; Okamura, K.; Mahoe, R.; Yogi, M.; Amakai, Y.; Takano, H.; Murayama, S.; Obi, Y.

2009-03-01

199

Weak Magnetic Order in Bilayered-Hydrate NaxCoO2\\\\cdotyH2O Structure Probed by Co Nuclear Quadrupole Resonance Proposed Phase Diagram in Superconducting NaxCoO2\\\\cdotyH2O---  

Microsoft Academic Search

A weak magnetic order was found in a nonsuperconducting bilayered-hydrate NaxCoO2\\\\cdotyH2O sample by Co nuclear quadrupole resonance (NQR) measurement. The nuclear spin-lattice relaxation rate divided by temperature 1\\/T_1T shows a prominent peak at 5.5 K, below which a Co NQR peak splits due to an internal field at the Co site. From the analyses of the Co NQR spectrum at

Yoshihiko Ihara; Kenji Ishida; Chishiro Michioka; Masaki Kato; Kazuyoshi Yoshimura; Kazunori Takada; Takayoshi Sasaki; Hiroya Sakurai; Eiji Takayama-Muromachi

2005-01-01

200

Alternative Pyrimidine Biosynthesis Protein ApbE Is a Flavin Transferase Catalyzing Covalent Attachment of FMN to a Threonine Residue in Bacterial Flavoproteins*  

PubMed Central

Na+-translocating NADH:quinone oxidoreductase (Na+-NQR) contains two flavin residues as redox-active prosthetic groups attached by a phosphoester bond to threonine residues in subunits NqrB and NqrC. We demonstrate here that flavinylation of truncated Vibrio harveyi NqrC at Thr-229 in Escherichia coli cells requires the presence of a co-expressed Vibrio apbE gene. The apbE genes cluster with genes for Na+-NQR and other FMN-binding flavoproteins in bacterial genomes and encode proteins with previously unknown function. Experiments with isolated NqrC and ApbE proteins confirmed that ApbE is the only protein factor required for NqrC flavinylation and also indicated that the reaction is Mg2+-dependent and proceeds with FAD but not FMN. Inactivation of the apbE gene in Klebsiella pneumoniae, wherein the nqr operon and apbE are well separated in the chromosome, resulted in a complete loss of the quinone reductase activity of Na+-NQR, consistent with its dependence on covalently bound flavin. Our data thus identify ApbE as a novel modifying enzyme, flavin transferase. PMID:23558683

Bertsova, Yulia V.; Fadeeva, Maria S.; Kostyrko, Vitaly A.; Serebryakova, Marina V.; Baykov, Alexander A.; Bogachev, Alexander V.

2013-01-01

201

Image restoration using fast Fourier and wavelet transforms  

NASA Astrophysics Data System (ADS)

Pure nuclear quadrupole resonance (NQR) of 14N nuclei is quite promising as a method for detecting explosives such as RDX and contraband narcotics such as cocaine and heroin in quantities of interest. Pure NQR is conducted without an external applied magnetic field, so potential concerns about damage to magnetically encoded data or exposure of personnel to large magnetic fields are not relevant. Because NQR frequencies of different compounds are quite distinct, we do not encounter false alarms from the NQR signals of other benign materials. We have constructed a proof-of-concept NQR explosives detector which interrogates a volume of 300 liters (10 ft3). With minimal modification to the existing explosives detector, we can detect operationally relevant quantities of (free base) cocaine within the 300-liter inspection volume in 6 seconds. We are presently extending this approach to the detection of heroin base and also examining 14N and 35,37Cl pure NQR for detection of the hydrochloride forms of both materials. An adaptation of this NQR approach may be suitable for scanning personnel for externally carried contraband and explosives. We first outline the basics of the NQR approach, highlighting strengths and weaknesses, and then present representative results for RDX and cocaine detection. We also present a partial compendium of relevant NQR parameters measured for some materials of interest.

Harrod, William J.; Nagy, James G.; Plemmons, Robert J.

1994-02-01

202

Narcotics and explosives detection by 14N pure nuclear quadrupole resonance  

NASA Astrophysics Data System (ADS)

Pure nuclear quadrupole resonance (NQR) of 14N nuclei is quite promising as a method for detecting explosives such as RDX and contraband narcotics such as cocaine and heroin in quantities of interest. Pure NQR is conducted without an external applied magnetic field, so potential concerns about damage to magnetically encoded data or exposure of personnel to large magnetic fields are not relevant. Because NQR frequencies of different compounds are quite distinct, we do not encounter false alarms from the NQR signals of other benign materials. We have constructed a proof-of-concept NQR explosives detector which interrogates a volume of 300 liters (10 ft3). With minimal modification to the existing explosives detector, we can detect operationally relevant quantities of (free base) cocaine within the 300-liter inspection volume in 6 seconds. We are presently extending this approach to the detection of heroin base and also examining 14N and 35,37Cl pure NQR for detection of the hydrochloride forms of both materials. An adaptation of this NQR approach may be suitable for scanning personnel for externally carried contraband and explosives. We first outline the basics of the NQR approach, highlighting strengths and weaknesses, and then present representative results for RDX and cocaine detection. We also present a partial compendium of relevant NQR parameters measured for some materials of interest.

Garroway, Allen N.; Buess, Michael L.; Yesinowski, James P.; Miller, Joel B.

1994-03-01

203

Asian American Studies Comparative Ethnic Studies  

E-print Network

0 Asian American Studies Comparative Ethnic Studies Indigenous/Native American Studies Latino Studies CSER Student Guide 2012-13 Ethnicity & Race Center for the Study of #12;1 About CSER Founded in 1999, the Center for the Study of Ethnicity and Race (CSER) is a vibrant teaching, research and public

Qian, Ning

204

Phase transition and temperature dependent electronic state of an organic ferroelectric, phenazine chloranilic acid (1:1)  

NASA Astrophysics Data System (ADS)

The isotope effect of hydrogen motion in an organic ferroelectric, phenazine (Phz)-chloranilic acid (H2ca and D2ca for normal and deuterated compounds, respectively) co-crystal, was studied by 35Cl nuclear quadrupole resonance (NQR). Besides a ferroelectric transition at Tc = 253 K (303 K), a neutral-to-ionic transition was found below 170 K (200 K) for Phz-H2ca (Phz-D2ca). 1H-14N nuclear quadrupole double resonance measurements were also made in order to study the temperature dependent electronic state of Phz-(H/D)2ca. 14N NQR parameters suggested that donor orbital populations of the two nitrogen atoms in a phenazine molecule become nonequivalent (1.78 and 1.97) in the ferroelectric phase, while they are both equal to 1.89 in the paraelectric phase. In the ionic phase of Phz-D2ca, which was obtained by cooling below 188 K, they became 1.50 and 1.95, suggesting a proton transfer from D2ca to Phz.

Asaji, T.; Seliger, J.; Zagar, V.; Sekiguchi, M.; Watanabe, J.; Gotoh, K.; Ishida, H.; Vrtnik, S.; Dolinšek, J.

2007-06-01

205

Fostering Effective Studying and Study Planning with Study Questions  

ERIC Educational Resources Information Center

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…

Wilhelm, Pascal; Pieters, Jules M.

2007-01-01

206

Role of bromine in restoring superconductivity in YBa2Cu3Oy  

NASA Astrophysics Data System (ADS)

63,65Cu nuclear quadrupole resonance (NQR), 63,65Cu and 79,81Br nuclear magnetic resonance (NMR), and Br K-edge x-ray-absorption fine-structure (XAFS) measurement techniques have been used to study the local structures of Cu and Br in well-characterized samples of deoxygenated and brominated YBa2Cu3Oy (YBCO). The combined results provide a detailed picture of the role of bromine in reoxygenating the YBCO structure and an explanation for the partial restoration of superconductivity in the YBCO system. Characterization of the powder samples, with particle sizes of 1, 20, 30, and 40 ?m, included x-ray diffraction, thermal gravimetric analysis, energy dispersive x-ray analysis, and magnetometry. From the XAFS and NMR results, it is concluded that, upon bromination at 260 °C, Br does not enter the YBCO lattice either substitutionally or interstitially. Instead, there is compelling evidence for the formation of nanoscale BaBr2 precipitates which result from the local destruction of the YBa2Cu3Oy phase. Furthermore, on the basis of the NQR and NMR experiments, it is concluded that through this decomposition into an inhomogeneous material, oxygen is liberated which repopulates the nearby O(4) chain sites, thus restoring superconductivity.

Potrepka, D. M.; Budnick, J. I.; Fenner, D. B.; Hines, W. A.; Balasubramanian, M.; Moodenbaugh, A. R.

1999-10-01

207

Aspartic acid 397 in subunit B of the Na+-pumping NADH:quinone oxidoreductase from Vibrio cholerae forms part of a sodium-binding site, is involved in cation selectivity, and affects cation-binding site cooperativity.  

PubMed

The Na(+)-pumping NADH:quinone complex is found in Vibrio cholerae and other marine and pathogenic bacteria. NADH:ubiquinone oxidoreductase oxidizes NADH and reduces ubiquinone, using the free energy released by this reaction to pump sodium ions across the cell membrane. In a previous report, a conserved aspartic acid residue in the NqrB subunit at position 397, located in the cytosolic face of this protein, was proposed to be involved in the capture of sodium. Here, we studied the role of this residue through the characterization of mutant enzymes in which this aspartic acid was substituted by other residues that change charge and size, such as arginine, serine, lysine, glutamic acid, and cysteine. Our results indicate that NqrB-Asp-397 forms part of one of the at least two sodium-binding sites and that both size and charge at this position are critical for the function of the enzyme. Moreover, we demonstrate that this residue is involved in cation selectivity, has a critical role in the communication between sodium-binding sites, by promoting cooperativity, and controls the electron transfer step involved in sodium uptake (2Fe-2S ? FMNC). PMID:24030824

Shea, Michael E; Juárez, Oscar; Cho, Jonathan; Barquera, Blanca

2013-10-25

208

Effect of a weak static magnetic field on nitrogen-14 quadrupole resonance in the case of an axially symmetric electric field gradient tensor.  

PubMed

The application of a weak static B0 magnetic field (less than 1 mT) may produce a well-defined splitting of the (14)N Quadrupole Resonance line when the electric field gradient tensor at the nitrogen nucleus level is of axial symmetry. It is theoretically shown and experimentally confirmed that the actual splitting (when it exists) as well as the line-shape and the signal intensity depends on three factors: (i) the amplitude of B0, (ii) the amplitude and pulse duration of the radio-frequency field, B1, used for detecting the NQR signal, and (iii) the relative orientation of B0 and B1. For instance, when B0 is parallel to B1 and regardless of the B0 value, the signal intensity is three times larger than when B0 is perpendicular to B1. This point is of some importance in practice since NQR measurements are almost always performed in the earth field. Moreover, in the course of this study, it has been recognized that important pieces of information regarding line-shape are contained in data points at the beginning of the free induction decay (fid) which, in practice, are eliminated for avoiding spurious signals due to probe ringing. It has been found that these data points can generally be retrieved by linear prediction (LP) procedures. As a further LP benefit, the signal intensity loss (by about a factor of three) is regained. PMID:24183810

Guendouz, Laouès; Aissani, Sarra; Marêché, Jean-François; Retournard, Alain; Marande, Pierre-Louis; Canet, Daniel

2013-01-01

209

NMR reveals double occupancy of quinone-type ligands in the catalytic quinone binding site of the Na+-translocating NADH:Quinone oxidoreductase from Vibrio cholerae.  

PubMed

The sodium ion-translocating NADH:quinone oxidoreductase (Na(+)-NQR) from the pathogen Vibrio cholerae exploits the free energy liberated during oxidation of NADH with ubiquinone to pump sodium ions across the cytoplasmic membrane. The Na(+)-NQR consists of four membrane-bound subunits NqrBCDE and the peripheral NqrF and NqrA subunits. NqrA binds ubiquinone-8 as well as quinones with shorter prenyl chains (ubiquinone-1 and ubiquinone-2). Here we show that the quinone derivative 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB), a known inhibitor of the bc1 and b6f complexes found in mitochondria and chloroplasts, also inhibits quinone reduction by the Na(+)-NQR in a mixed inhibition mode. Tryptophan fluorescence quenching and saturation transfer difference NMR experiments in the presence of Na(+)-NQR inhibitor (DBMIB or 2-n-heptyl-4-hydroxyquinoline N-oxide) indicate that two quinone analog ligands are bound simultaneously by the NqrA subunit with very similar interaction constants as observed with the holoenzyme complex. We conclude that the catalytic site of quinone reduction is located on NqrA. The two ligands bind to an extended binding pocket in direct vicinity to each other as demonstrated by interligand Overhauser effects between ubiquinone-1 and DBMIB or 2-n-heptyl-4-hydroxyquinoline N-oxide, respectively. We propose that a similar spatially close arrangement of the native quinone substrates is also operational in vivo, enhancing the catalytic efficiency during the final electron transfer steps in the Na(+)-NQR. PMID:24003222

Nedielkov, Ruslan; Steffen, Wojtek; Steuber, Julia; Möller, Heiko M

2013-10-18

210

AGRICULTURAL HEALTH STUDY/PESTICIDE EXPOSURE STUDY  

EPA Science Inventory

The Agricultural Health Study (AHS) is a prospective epidemiologic study of a large cohort of pesticide applicators and their spouses in Iowa and North Carolina. The Pesticide Exposure Study is a sub-study to evaluate exposure factors and to provide data to assess exposure cla...

211

Extension Specialist Case Studies Case Study 1  

E-print Network

Extension Specialist Case Studies Case Study 1: A horticulture extension specialist is located. Case Study 2: A small grains extension specialist is located on campus at OSU. He is housed which way to vote on this case? file: P&T case studies.doc #12;

Tullos, Desiree

212

Professor, Communication Studies and African American Studies  

E-print Network

Professor, Communication Studies and African American Studies Director of African American Studies Program Ph.D., Indiana University, 1998 Information Technology Solutions February 16, 2012 6:30pm, Africana Studies, Office of Multicultural Student Affairs, Office of Academic Enhancement, BOND & UBS

Miami, University of

213

STUDY ABROADFOR BIOLOGY MAJORS study abroad  

E-print Network

of Molecular Cell and Developmental Biology, College of Natural Sciences #12;QUESTIONS · Visit the Biological to Biology degree requirements. Visit the "My Credit Abroad" database online to view direct course matchesSTUDY ABROADFOR BIOLOGY MAJORS study abroad #12;WHY YOU SHOULD STUDY ABROAD 2 STUDY ABROAD

Pillow, Jonathan

214

Africana Studies 45. . . . . . . . . . . . . . . . . . . American Studies 51. . . . . . . . . . . . . . . . . .  

E-print Network

. . . . . . . . . . . . . . . . . . . . . . German 182. . . . . . . . . . . . . . . . . . . . . . . . . . History 185. . . . . . . . . . . . . . . . . . . . . . . . . . History of Science 207. . . . . . . . . . . . . . . . . Interdisciplinary Studies Program 208. . . . . . . . . . . . . . . . . . . . . . . . Romance Languages 293. . . . . . . . . . . . . . Russian 303

Aalberts, Daniel P.

215

Peace Studies in Universities.  

ERIC Educational Resources Information Center

Defines peace studies from various points of view, identifies problems often encountered in setting up peace studies programs, presents examples of the kinds of issues which might be studied in peace studies programs, and suggests activities appropriate for students of peace studies. Journal available from World Studies Resource Center, Groby…

Curle, Adam

1980-01-01

216

Medieval Studies UNDERGRADUATE  

E-print Network

341 Medieval Studies UNDERGRADUATE PROGRAMS The Center for Medieval and Renaissance Studies (CEMERS) offers a major and a minor in medieval studies. BA in Medieval Studies The major in medieval studies normally be chosen from the current list of courses in medieval studies, in accordance

Suzuki, Masatsugu

217

14N nuclear quadrupole coupling in cyclic amides and thioamides. Ab initio simulations of the solid state environment as interpretation of the NQR spectra of 2-pyridinone, isatin and benzothiazole-2-one. A new x-ray structure for isatin  

NASA Astrophysics Data System (ADS)

A new determination of the X-ray structure of isatin is reported. Ab initio SCF calculations of the local crystal environment in 2-pyridinone (a trimeric structure) and each of isatin and benzothiazole-2-one (dimeric structures) are reported. In view of the importance of the N?H bond lengths in the bicyclic compounds, these were treated as variables in the computations, and found to be relatively short (1.01 Å). In all three molecules ? zz lies out of plane both in the monomeric and dimer and trimer calculations but in the last two types a reduction in magnitude of ? zz occurs.

Palmer, Michael H.; Blake, Alexander J.; Gould, Robert O.

1987-07-01

218

Investigation of the electronic effects in a series of halo derivatives of organosilicon compounds by the method of nuclear quadrupole resonance of 79 Br, 81 Br, and 127 I  

Microsoft Academic Search

1.The NQR spectra of certain bromo and iodo derivatives of organosilicon compounds were investigated.2.The correlation of the NQR frequencies and the quadrupole coupling constants with the induction and conjugation constants of the substituents at the silicon atom was constructed.

G. K. Semin; E. V. Bryukhova; M. A. Kadina; G. V. Frolova

1971-01-01

219

Nuclear quadrupole resonance of 35Cl nuclei in glassy solution of chlorobenzene in pyridine  

Microsoft Academic Search

Pulsed nuclear quadrupole resonance (NQR) measurements of 35Cl nuclei were performed on 43.5 mol % chlorobenzene solution in pyridine (a) in glassy state (Tg=131 K) after quenching in liquid nitrogen and (b) in crystalline precipitate under slow cooling starting from liquid phase. In both cases the NQR line shape, obtained by the fast Fourier transform (FFT) method, consisted of a

A. E. Wolfenson; A. H. Brunetti; D. J. Pusiol; W. M. Pontuschka

1990-01-01

220

Nondestructive testing of adhesive bonds by nuclear quadrupole resonance method  

NASA Technical Reports Server (NTRS)

Inert, strain sensitive tracer, cuprous oxide, added to polymeric adhesive ensures sufficiently large signal to noise ratio in NQR system output. Method is successful, provided that RF-transparent structural materials are used between modified adhesive and probe of NQR spectrometer.

Hewitt, R. R.

1971-01-01

221

Women's Studies (undergraduate)  

E-print Network

348 Women's Studies (undergraduate) The Women's Studies Program offers an interdisciplinary course of study in the historical, economic, political, social and cultural experi- ence of women. The program courses in women's studies. Each semester the Women's Studies Department publishes a list of courses

Suzuki, Masatsugu

222

The Role of Glycine Residues 140 and 141 of Subunit B in the Functional Ubiquinone Binding Site of the Na+-pumping NADH:quinone Oxidoreductase from Vibrio cholerae*  

PubMed Central

The Na+-pumping NADH:quinone oxidoreductase (Na+-NQR) is the main entrance for electrons into the respiratory chain of many marine and pathogenic bacteria. The enzyme accepts electrons from NADH and donates them to ubiquinone, and the free energy released by this redox reaction is used to create an electrochemical gradient of sodium across the cell membrane. Here we report the role of glycine 140 and glycine 141 of the NqrB subunit in the functional binding of ubiquinone. Mutations at these residues altered the affinity of the enzyme for ubiquinol. Moreover, mutations in residue NqrB-G140 almost completely abolished the electron transfer to ubiquinone. Thus, NqrB-G140 and -G141 are critical for the binding and reaction of Na+-NQR with its electron acceptor, ubiquinone. PMID:22645140

Juárez, Oscar; Neehaul, Yashvin; Turk, Erin; Chahboun, Najat; DeMicco, Jessica M.; Hellwig, Petra; Barquera, Blanca

2012-01-01

223

Spring 2010 Global Studies  

E-print Network

. Presenters Kayla Backus Senior, French, and Global Studies minor Study abroad site: Paris, France Education, France Language Acquisition through are informed by on-going conversations from our Global Studies Minor courses. Students enrolled in the Minor

Suzuki, Masatsugu

224

Studies That Observe Humans  

MedlinePLUS

... information can be a good place to start. Case control studies: These studies look at people who already have ... got cancer and the other didn’t. Most case-control studies are retrospective (meaning that they look back at ...

225

ATBC Study - Contact Us  

Cancer.gov

Skip to Main Content Home Contact Us Links Study Details Questionnaires & Forms Current Projects ATBC Study Bibliography Study Investigators & Collaborators Proposal Review & Collaboration Research Consortium Projects Contact Us If you are seeking general

226

Peace Studies and the Social Studies.  

ERIC Educational Resources Information Center

Numerous reasons can be given for the low quality of teaching in the social studies. Teachers may be improperly certified, or they may teach to maintain employment rather than to do a good job. To teach peace studies courses requires the cream of the crop in terms of quality instruction. Teachers should be well above the minimum requirements for…

Ediger, Marlow

227

Study HabitsStudy Habits Homework strategies  

E-print Network

Study HabitsStudy Habits Homework strategies #12;Course structureCourse structure · In here you have homeworks that tend to relyIn here you have homeworks that tend to rely on handwritten work · You thoughts · Treat your homeworks & projects as you ld l twould lecture ­ They are part of the course

Wolverton, Steve

228

Silent study zone Quiet study zone  

E-print Network

Archaeology 4E Architecture 3W Art 3W Assistive technology 2C Astronomy 2W B Borrower & Library account study spaces Quiet study spaces Music Classmark M Arts and Architecture Classmark N Politics Engineering & Technology Military & Naval Science Classmarks R S T U V Bibliography Classmark Z Sciences Maths

Banaji,. Murad

229

Ethnographic Study: @ONE Technology Training Project Study.  

ERIC Educational Resources Information Center

This report presents findings from an ethnographic study of technology integration and diffusion in two California community colleges. The study was commissioned to examine whether faculty behavior and student learning outcomes have changed as a result of @ONE instructional technology training and resources. The California Community Colleges…

Obler, Susan; Schiorring, Eva

230

Social Studies Graded Course of Study. [Revised].  

ERIC Educational Resources Information Center

This revised Stark County (Ohio) curriculum guide provides a basic framework for a sequential grades K-12 social studies program. The guide contains the program's philosophy and goals, information about student evaluation, and position statements on social studies, citizenship education, and conceptual learning. The section on elementary education…

Stark County Dept. of Education, Louisville, OH.

231

Social Studies Graded Course of Study.  

ERIC Educational Resources Information Center

Basic social studies concepts and corresponding generalizations serve as the overall framework holding together the changing content of the curriculum in this guide. The K-6 organization of skills and concepts reflects an integrated social studies curriculum representing all the social sciences. The K-6 scope and sequence integrates five major…

Stark County Dept. of Education, Louisville, OH.

232

Divinity Biblical Studies, Theological Studies, Hebrew,  

E-print Network

Classical StudiesX Comparative Literature Economics English Film Studies FrenchW Hebrew and one of: Arabic with flexibility of choice. * Learn to think critically about truth-claims and how people live in the light into the style of learning, ensuring that students are actively involved in the crafting of their education

Brierley, Andrew

233

INTERNATIONAL ASSOCIATION FOR LADAKH STUDIES LADAKH STUDIES  

E-print Network

INTERNATIONAL ASSOCIATION FOR LADAKH STUDIES LADAKH STUDIES NR. 29 February 2013 CONTENTS From Official in Ladakh in the early 1900s John Bray 20 Photo plates: Photo-essay: An Indian Official in Ladakh of Civilisation. by John Cook John Bray Legacy of a Mountain People. Inventory of Cultural Resources of Ladakh Vol

Paris-Sud XI, Université de

234

Generalizing from Case studies: A Case Study  

Microsoft Academic Search

Most empirical evaluations of machine learningalgorithms are case studies -- evaluationsof multiple algorithms on multiple databases.Authors of case studies implicitly or explicitlyhypothesize that the pattern of theirresults, which often suggests that one algorithmperforms significantly better thanothers, is not limited to the small numberof databases investigated, but instead holdsfor some general class of learning problems.However, these hypotheses are rarely supportedwith...

David W. Aha

1992-01-01

235

Summer Studies CALENDAR 2010  

E-print Network

Summer Studies UNIVERSITY CALENDAR 2010 #12;McGill University, 2010 Summer Studies 1 ABOUT About This Calendar Published by: McGill Summer Studies McGill University 688 Sherbrooke Street West, Suite 1029, and changes can be made after this Calendar is published. Please check the Summer Studies website at www.mcgill.ca/summer

Fabry, Frederic

236

Graduate School POLICY STUDIES  

E-print Network

Graduate School Graduate School POLICY STUDIES Doctor of Philosophy Certificate clemson university offers graduate studies leading to a Phd degree and a certificate in Policy Studies. Graduate work in policy studies enables a student to attain a high degree of specialized competence in policy analysis

Stuart, Steven J.

237

study programs in mathematics  

E-print Network

study programs in m mathematics #12;#12;3 CONTENTS 5 Introduction 7 Mathematics at the University of Ljubljana 9 Department of Mathematics information page Academic study program in Mathematics Academic study program in Financial Mathematics Single cycle master's study program in Mathematics education

Â?umer, Slobodan

238

Communication Studies, Cultural Studies, and Media Studies Infobase  

NSDL National Science Digital Library

Mick Underwood's extensive infobase of communication, culture, and media studies introduces various models and theories of communication and explains their social and cultural implications. In addition, the infobase includes a detailed index of terms, a bibliography of references, a list of links, a message forum, a chat room, and a series of online quizzes. The great volume of information at this site is effectively managed via several navigation tools: a site map, an index, pull-down menus, and meaningful icons.

239

Electrodynamic tether system study: Extended study  

NASA Technical Reports Server (NTRS)

This document is the final report of a study performed by Ball Space Systems Division (BSSD) for the NASA Johnson Space Center under an extension to contract NAS9-17666. The tasks for the extended study were as follows: (1) Define an interface between the Electrodynamic Tether System (ETS) and the Space Station (SS); (2) Identify growth paths for the 100 kW ETS defined in the original study to a 200 kW level of performance; (3) Quantify orbit perturbations caused by cyclic day/night operations of a Plasma Motor/Generator (PMG) on the SS and explore methods of minimizing these effects; (4) Define the analyses, precursor technology, ground tests, and precursor demonstrations leading up to a demonstration mission for an electrodynamic tether system that would be capable of producing maneuvering thrust levels of 25 newtons; and (5) Propose a development schedule for the demonstration mission and preliminary cost estimates.

1988-01-01

240

HUMANITIES SCHOLARS APPLICATION Africana Studies  

E-print Network

HUMANITIES SCHOLARS APPLICATION MAJORS Africana Studies American Studies Ancient Studies Anthropology, Cultural Asian Studies English Gender and Women's Studies History Media and Communication Studies Modern Languages, Linguistics and Intercultural Communication Philosophy Interdisciplinary Studies #12

Maryland, Baltimore County, University of

241

The Study of Algae  

ERIC Educational Resources Information Center

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)

Rushforth, Samuel R.

1977-01-01

242

Punnett Square Case Study  

NSDL National Science Digital Library

In this lesson, students will gain experience using Punnett Squares. The case study determines the probability of children having freckles from a freckled father and non-freckled mother. Illustrations guide each step of the case study.

243

Melbourne Collaborative Cohort Study  

Cancer.gov

The Melbourne Collaborative Cohort Study is a longitudinal study established in the 1990s by Cancer Council Victoria to investigate prospectively the role of diet and other lifestyle factors in cancer.

244

Case Study Teaching  

ERIC Educational Resources Information Center

This chapter describes the history of case study teaching, types of cases, and experimental data supporting their effectiveness. It also describes a model for comparing the efficacy of the various case study methods. (Contains 1 figure.)

Herreid, Clyde Freeman

2011-01-01

245

FUEL DELIVERY TEMPERATURE STUDY  

E-print Network

CALIFORNIA ENERGY COMMISSION FUEL DELIVERY TEMPERATURE STUDY COMMISSIONREPORT March 2009 CEC-600 and Nicholas Janusch, 2009. Fuel Delivery Temperature Study, California Energy Commission. CEC-600-2009-002-CMF

246

Participate in a Study  

MedlinePLUS

... participate in research studies. Each study that uses human subjects must be approved and monitored by the Institutional Review Board (IRB) of the institution where the research is to be conducted. The IRB’s job is ...

247

Case Study: Missing Link  

NSDL National Science Digital Library

This is a case study for high school and/or undergraduate students in physical anthropology. In particular this case study explores skull anatomy. Users of the National Center for Case Study Teaching in Science will be required to register (free) to gain access to the answer key (and must be of teaching status to receive the key). Included in the resource are the case overview, objectives, case study, teaching notes and answer key.

Elizabeth Strasser (Sacramento State Anthropology)

2000-09-02

248

studies CP2001 Constraints  

E-print Network

CP'01 Part III ­ Case studies CP2001 Tutorial ­ Cyprus November 2001 ­ Case studies -- p.1/20 #12 from a single sequence. CP2001 Tutorial ­ Cyprus November 2001 ­ Case studies -- p.3/20 #12; CP'01 A transfert RNA CP2001 Tutorial ­ Cyprus November 2001 ­ Case studies -- p.4/20 #12; CP'01 RNA secondary

Rossi, Francesca

249

Case Study: Uretero What?  

NSDL National Science Digital Library

This is a case study for high school, undergraduate and/or professional students in physiology and anatomy. In particular this case study explores reproductive biology. Users of the National Center for Case Study Teaching in Science will be required to register (free) to gain access to the answer key (and must be of teaching status to receive the key). Included in the resource are the case overview, objectives, case study, teaching notes and answer key.

Laura Lorentzen (Kean University Science and Technology Education)

2008-04-08

250

Case Study: Ellen's Choice  

NSDL National Science Digital Library

This is a case study for undergraduate students in anatomy and physiology. In particular this case study explores spinal anatomy, aging of bone, and explores the basic physiology of inflammation. Users of the National Center for Case Study Teaching in Science will be required to register (free) to gain access to the answer key (and must be of teaching status to receive the key). Included in the resource are the case overview, objectives, case study, teaching notes and answer key.

Elizabeth Harper (New York University Steinhardt School of Education Department of Health Studies)

2001-04-03

251

258 / Near Eastern Studies Near Eastern Studies  

E-print Network

. Kyle McCarter Jr., Professor, William Foxwell Albright Chair in Biblical and Ancient Near Eastern Majors, page 47.) All students majoring in Near Eastern studies must take two years of one Near Eastern (130.300-303) or be equivalent courses tailored to the student's individual interests and needs

Niebur, Ernst

252

Labour Studies Labour Studies is about revealing  

E-print Network

will study a range of social issues, including poverty, unemployment, gender discrimination, human rights requires students to design, conduct and apply a research project to a real community or workplace issue resource management · Industrial relations · Employment training · Career counselling and placement

253

Indian Studies Program.  

ERIC Educational Resources Information Center

A product of the Indian Studies Curriculum Committee and the Indian Studies Staff, this manual on the Indians of Southeast Alaska constitutes a useable classroom tool designed for the cross-cultural program in the Juneau School District. Objectives of this Indian Studies Program are identified as: to increase knowledge, awareness, and positive…

Peck, Cy, Sr.; And Others

254

Cave Water Studies.  

ERIC Educational Resources Information Center

Describes a comparative study project where seventh grade students tested water samples from 10 cave sites that had been tested 24 years ago in a study that had attempted to determine if pollution in the environment had reached cave water. Discusses lab skills and some results of the study. (JRH)

O'Keefe, Elizabeth S.

1996-01-01

255

Social Psychoanalytic Disability Studies  

ERIC Educational Resources Information Center

This paper explores connections and tensions between psychoanalysis and disability studies. The first part of the paper considers contemporaneous engagements with the psyche by a number of disability studies writers. These scholars have remained accountable to a politicised disability studies but have pushed for critical encounters with the…

Goodley, Dan

2011-01-01

256

Home Start Evaluation Study.  

ERIC Educational Resources Information Center

Case studies of eight Home Start programs are given as the third section of an evaluation study. Communities involved are Binghamton, New York; Franklin, North Carolina; Cleveland, Ohio; Harrogate, Tennessee; Houston, Texas; Weslaco, Texas; Millville, Utah; Parkersburg, West Virginia. Although each study varies in format, each describes in detail…

High/Scope Educational Research Foundation, Ypsilanti, MI.

257

Student Access Study.  

ERIC Educational Resources Information Center

This study of Wyoming citizen access to community college education explored several factors related to college enrollments over the period 1990-1997. The study further examined projected student enrollment for 1998-2006. This study reports on the findings for: (1) Wyoming population trends and community college enrollments and projected…

Wyoming Community Coll. Commission, Cheyenne.

258

Interdisciplinary study program  

E-print Network

75 Interdisciplinary academic study program computer science and mathematics mc #12;76 #12;· Study: 3 full years (6 terms) based on 180 ECTS credits · Basic goals of the program and competences acquired by the program: The Interdisciplinary academic study program in Computer Science and Mathematics

Â?umer, Slobodan

259

ATBC Study - Current Projects  

Cancer.gov

Skip to Main Content Home Contact Us Links Study Details Questionnaires & Forms Current Projects ATBC Study Bibliography Study Investigators & Collaborators Proposal Review & Collaboration Research Consortium Projects Current Projects Prostate Lung Colorectal Pancreas Bladder Gastric Esophagus Renal Lymphomas/Leukemias Liver/biliary Head

260

WISCONSIN LONGITUDINAL STUDY (WLS)  

EPA Science Inventory

The Wisconsin Longitudinal Study (WLS) is a long-term study of a random sample of 10,317 men and women who graduated from Wisconsin high schools in 1957. The WLS provides an opportunity to study of the life course, intergenerational transfers and relationships, family functioning...

261

Czech residential radon study  

Microsoft Academic Search

Background: Epidemiological evidence of lung cancer risk from radon is based mainly on studies of men working underground in mines, where exposures are relatively high in comparison to indoor exposure. Risk from residential radon can be estimated from occupational studies. Nevertheless, as such extrapolations depend on a number of assumptions, direct estimation of the risk is needed. Methods: The study

Ladislav Tomášek; TomᚠMüller; Emil Kunz; Alena Heribanová; Jan Matzner; Václav Pla?ek; Ivo Burian; Josef Hole?ek

2002-01-01

262

NYU Women's Health Study  

Cancer.gov

For more than 25 years, the NYU Women’s Health Study has been committed to studying the potential causes of serious diseases in women in the United States. When the study began in 1985, its goal was to identify the role of hormones and diet in the development of the most common cancers in women, especially breast cancer.

263

Case Studies Volunteering  

E-print Network

Case Studies Volunteering on the national forest estate #12;Contents Foreword 3 Introduction 4 Vol by Minister for Environment, Michael Russell This impressive array of case studies shows the huge amount and their locality so creating stronger and safer communities. These case studies show excellent examples of all

264

Home Start Evaluation Study.  

ERIC Educational Resources Information Center

Case studies of seven Home Start programs are given as the third section of an evaluation study. Communities involved are Huntsville, Alabama; Fairbanks, Alaska; Fort Defiance, Arizona; Dardanelle, Arkansas; Wichita, Kansas; Gloucester, Massachusetts; and Reno, Nevada. Although each study varies in format, each describes in detail the degree and…

High/Scope Educational Research Foundation, Ypsilanti, MI.

265

Judaic Studies (undergraduate)  

E-print Network

151 Judaic Studies (undergraduate) FACULTY * Year of initial appointment at Binghamton Arkush COMPONENTS The Judaic Studies Department offers two BA degrees and two minor concentrations: a major and minor in Hebrew language and literature. Because of the interdisciplinary nature of Judaic studies

Suzuki, Masatsugu

266

study programs in mathematics  

E-print Network

study programs in m mathematics 1_ matematika 2008.qxp 16.7.2008 16:41 Page 1 #12;1_ matematika 2008.qxp 16.7.2008 16:41 Page 2 #12;3 CONTENTS 5 Introduction 7 Mathematics at the University of Ljubljana 9 Department of Mathematics information page Academic study program in Mathematics Academic study

Â?umer, Slobodan

267

Women's Studies Intellectually stimulating,  

E-print Network

of disciplines such as Women's Studies, Psychology and Sociology · Correctional services · Women's sheltersWomen's Studies Intellectually stimulating, personally fulfilling, and more practical than you might think. The breadth and depth of Women's Studies will amaze you. Our goal is to help you "find your

268

ACCELERATOR RESEARCH STUDIES  

SciTech Connect

ACCELERATOR RESEARCH STUDIES Task A: Study of the Physics of Space-Charge Dominated Beams for Advanced Accelerator Applications Task B: Studies of High-Power Gyroklystrons and Application to Linear Colliders Task C: Theory and Simulation of the Physics Space-Charge Dominated Beams Annual Report for the Period June 1, 2003 to May 31, 2004

P.G. O'Shea, M. Reiser, V. L. Granatstein, W. Lawson, I. Haber, R. Kishek

2004-01-23

269

Renewable Electricity Futures Study  

E-print Network

Renewable Electricity Futures Study Bulk Electric Power Systems: Operations and Transmission by the Alliance for Sustainable Energy, LLC. #12;Renewable Electricity Futures Study Edited By Hand, M.M. National Suggested Citations Renewable Electricity Futures Study (Entire Report) National Renewable Energy Laboratory

270

Renewable Electricity Futures Study  

E-print Network

Renewable Electricity Futures Study End-use Electricity Demand Volume 3 of 4 Volume 2 PDF Volume 3;Renewable Electricity Futures Study Edited By Hand, M.M. National Renewable Energy Laboratory Baldwin, S. U Sandor, D. National Renewable Energy Laboratory Suggested Citations Renewable Electricity Futures Study

271

Renewable Electricity Futures Study  

E-print Network

Renewable Electricity Futures Study Exploration of High-Penetration Renewable Electricity Futures PDF Volume 4 PDF #12;Renewable Electricity Futures Study Edited By Hand, M.M. National Renewable Citations Renewable Electricity Futures Study (Entire Report) National Renewable Energy Laboratory. (2012

272

Mars Aerocapture Systems Study  

NASA Technical Reports Server (NTRS)

Mars Aerocapture Systems Study (MASS) is a detailed study of the application of aerocapture to a large Mars robotic orbiter to assess and identify key technology gaps. This study addressed use of an Opposition class return segment for use in the Mars Sample Return architecture. Study addressed mission architecture issues as well as system design. Key trade studies focused on design of aerocapture aeroshell, spacecraft design and packaging, guidance, navigation and control with simulation, computational fluid dynamics, and thermal protection system sizing. Detailed master equipment lists are included as well as a cursory cost assessment.

Wright, Henry S.; Oh, David Y.; Westhelle, Carlos H.; Fisher, Jody L.; Dyke, R. Eric; Edquist, Karl T.; Brown, James L.; Justh, Hilary L.; Munk, Michelle M.

2006-01-01

273

UBC CASE STUDY / Social, Ecological, Economical Developmental Studies (SEEDS) UBC CASE STUDY/  

E-print Network

UBC CASE STUDY / Social, Ecological, Economical Developmental Studies (SEEDS) UBC CASE STUDY/ SOCIAL, ECOLOCIAL, ECONOMIC DEVELOPMENT STUDIES (SEEDS) UBC Sustainability Office CASE STUDY/ SOCIAL, ECOLOCIAL, ECONOMIC DEVELOPMENT STUDIES (SEEDS) UBC Campus Sustainability Office #12;UBC CASE STUDY / Social

274

Physics studies in Europe; a comparative study  

NASA Astrophysics Data System (ADS)

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 survey. During 1997 and 1998 the working groups of EUPEN sent out a number of questionnaires to a number of institutions and to individual students. In this report we focus on issues relating to the workload to obtain a degree in physics as expressed in contact hours - lectures, problem solving, laboratory work - and private study time. The different teaching/learning styles are also considered. Some of the results have already been presented at conferences.

Steenstrup, S.; Donà dalle Rose, L. F.; Jones, W. G.; Tugulea, L.; van Steenwijk, F. J.

2002-09-01

275

Optical and Nuclear Spin Spectroscopy in PRASEODYMIUM(3+):LANTHANUM Fluoride by Optical Pumping  

NASA Astrophysics Data System (ADS)

A Stark Modulated Optical Pumping (SMOP) technique was used as a sensitive probe of optical hole-burning to study the effects of nuclear spin interactions in Pr ^{3+}:LaF_3. The results of two experiments are reported. In the first experiment, the SMOP technique is applied for optical detection of the NQR spectrum of the Pr^{3+} optical ground state. Frequency and linewidth variations of the Pr ^{3+} ground state hyperfine levels for different positions within the main ^3 H_4(Gamma1) -^1D_2(Gamma 1) inhomogeneous optical line and satellite transitions of Pr^{3+}:LaF _3 are observed. A linear increase in the broadening of the Pr^{3+} hyperfine transitions, without a shift of central frequency, is measured as the laser is tuned toward the wings of the inhomogeneous optical transition. The linear variation is attributed to electric quadrupole broadening caused by changes in local density of point defects across the Stark broadened optical transition. The optically detected NQR spectra of the satellite transitions associated with Pr ion pairs are shifted in frequency, and for most satellites are narrower in width than the NQR spectra found in the wings of the main inhomogeneous optical line. In the second experiment, direct evidence for the presence of a spin diffusion barrier or "frozen core" in Pr^{3+}:LaF _3 is observed by examining the cross relaxation between the Pr and F nuclei in a magnetic field chosen so that a pair of the optical ground state Pr^ {3+} hyperfine energy levels matches the F splitting or a multiple of the F splitting. This level crossing condition allows resonant flip-flop interactions with the nearest neighbor frozen core fluorine spins to re-populate Pr^{3+} hyperfine levels emptied by laser hole-burning, and is detected as enhanced absorption of the laser beam. The coupling of core fluorine spins to bulk fluorine spins during Pr-F cross-relaxation is measured by NMR of the bulk fluorine spin magnetization. The rate of cross relaxation between the Pr spins and the bulk F spins measured in this way is at least three to four orders of magnitude slower than that expected in the absence of a spin diffusion barrier. This reduction of coupling indicates nearly complete de-tuning of the frozen core F spins immediately surrounding the Pr^{3+} ion, cutting off resonant coupling with the bulk F spins.

Wald, Lawrence Leroy

276

Peptide backbone orientation and dynamics in spider dragline silk and two-photon excitation in nuclear magnetic and quadrupole resonance  

NASA Astrophysics Data System (ADS)

In the first part of the dissertation, spider dragline silk is studied by solid state NMR techniques. The dependence of NMR frequency on molecular orientation is exploited using the DECODER experiment to determine the orientation of the protein backbone within the silk fibre. Practical experimental considerations require that the silk fibres be wound about a cylindrical axis perpendicular to the external magnetic field, complicating the reconstruction of the underlying orientation distribution and necess-itating the development of numerical techniques for this purpose. A two-component model of silk incorporating static b-sheets and polyglycine II helices adequately fits the NMR data and suggests that the b-sheets are well aligned along the silk axis (20 FWHM) while the helices are poorly aligned (68 FWHM). The effects of fibre strain, draw rate and hydration on orientation are measured. Measurements of the time-scale for peptide backbone motion indicate that when wet, a strain-dependent frac-tion of the poorly aligned component becomes mobile. This suggests a mechanism for the supercontraction of silk involving latent entropic springs that undergo a local strain-dependent phase transition, driving supercontraction. In the second part of this dissertation a novel method is developed for exciting NMR and nuclear quadrupole resonance (NQR) by rf irradiation at multiple frequencies that sum to (or differ by) the resonance frequency. This is fundamentally different than traditional NMR experiments where irradiation is applied on-resonance. With excitation outside the detection bandwidth, two-photon excitation allows for detection of free induction signals during excitation, completely eliminating receiver dead-time. A theoretical approach to describing two-photon excitation is developed based on average Hamiltonian theory. An intuition for two-photon excitation is gained by analogy to the coherent absorption of multiple photons requiring conservation of total energy and momentum. It is shown that two-photon excitation efficiency impro-ves when the two applied rf frequencies deviate from half-resonance. For two-photon NQR, it is shown that observable magnetization appears perpendicular to the excita-tion coil, requiring a second coil for detection, and that double quantum coherences are also generated. Several model systems and experimental geometries are used to demonstrate the peculiarities of two-photon excitation in NMR and NQR.

Eles, Philip Thomas

2005-07-01

277

HURI SURI: Case Studies  

NSDL National Science Digital Library

The HURI SURI project is developing a regional biotechnology workforce pipeline by expanding and supporting biotechnology research experiences for Jamestown Community College (JCC) undergraduates and disseminating these research experiences and materials to area high school teachers and students. This page includes two case studies, "Mosquito and walbachia" and "Heartworm Experimental Design." Students will examine these case studies and then complete the worksheet for the SCA in class case study

278

Pathology Case Study: Hydrocephalus  

NSDL National Science Digital Library

The University of Pittsburgh School of Medicine's Department of Pathology has compiled a series of case studies to help both students and instructors. In this particular study an otherwise healthy 9 month old infant is presented with hydrocephalus. The case study provides test results and images along with microscopic photos and description. Clicking on the final diagnosis provides a thorough explanation of the diagnosis and treatment.

2007-08-20

279

Southern Community Cohort Study  

Cancer.gov

The current body of knowledge regarding the etiology and prevention of cancer draws substantially from prospective epidemiologic studies, among which African Americans have been greatly underrepresented.

280

Case Study: Football Fanaticism  

NSDL National Science Digital Library

This is a case study for undergraduate and professional degree students in anatomy, physiology and/or pharmaceutical sciences. In particular this case study explores the anatomy of the central nervous system, major motor and sensory tracts. Integrative physiology courses may use this case to incorporate the immune, nervous and cardiovascular systems. Users of the National Center for Case Study Teaching in Science will be required to register (free) to gain access to the answer key (and must be of teaching status to receive the key). Included in the resource are the case overview, objectives, case study, teaching notes and answer key.

PhD Dayton J Ford (St. Louis College of Pharmacy Department of Pharmaceutical Sciences)

2003-07-03

281

Measuring Study Effectiveness  

NSDL National Science Digital Library

This model-eliciting activity challenges students to operationally define a construct (study effectiveness). Students are given a survey to review that rates different aspects of study behaviors. They are then given a set of data for a few students and asked to use their scores to determine an index of study effectiveness. After determining a method, they are then asked to use this index to put five students in rank order according to their scores on study effectiveness. Students write a report explaining the method they used to determine these scores and how they produced their ratings.

This page was authored by the CATALST Group at the University of Minnesota, based on an original activity by Richard Lesh at Purdue University.

282

STRATNET: Strategic Studies Network  

NSDL National Science Digital Library

The University of Calgary's Strategic Studies Program developed STRATNET to provide a network of research resources germane to the study of international relations, security, and politics. STRATNET includes three main sections: StratChat, an interactive discussion forum; StratLink, a well-organized collection of hundreds of annotated strategic studies pointers; and StratJournal, which contains a multidisciplinary online journal entitled STRATNET. In addition, the site provides information about the fellows and the outreach projects of the Strategic Studies Program at the University of Calgary.

283

Access to space studies  

NASA Astrophysics Data System (ADS)

The National Aeronautics and Space Administration is currently considering possible directions in Earth-to-orbit vehicle development under a study called 'Access to Space.' This agency-wide study is considering commercial launch vehicles, human transportation, space station logistics, and other space transportation requirements over the next 40 years. Three options are being considered for human transportation: continued use of the Space Shuttle; development of a small personnel carrier (personnel logistics system (PLS)); or development of an advanced vehicle such as a single-stage-to-orbit (SSTO). Several studies related to the overall Access to Space study are reported in this document.

Martin, James A.

1993-11-01

284

Xenia Spacecraft Study  

NASA Technical Reports Server (NTRS)

This slide presentation reviews the proposed design for the Xenia mission spacecraft. The goal of this study is to perform a mission concept study for the mission. Included in this study are: the overall ground rules and assumptions (GR&A), a mission analysis, the configuration, the mass properties, the guidance, Navigation and control, the proposed avionics, the power system, the thermal protection system, the propulsion system, and the proposed structures. Conclusions from the study indicate that the observatory fits within the Falcon 9 mass and volume envelope for launching from Omelek, the pointing, slow slewing, and fast slewing requirements and the thermal requirements are met.

Hopkins, Randy

2009-01-01

285

Future Spacelift Requirements Study  

NASA Technical Reports Server (NTRS)

This study addresses future space applications and the derived requirements these potential applications will have on future spacelift systems. This NASA sponsored activity is a comprehensive study of potential missions including those of the military, civil, and commercial users. The study objectively evaluated the key architectural requirements for future launch systems. The results of this study are technical, economic, and policy analyses of future spacelift systems. It is intended to assist NASA and DOD decision-makers in planning technical investments and establishing policy for future U.S. spacelift systems.

1997-01-01

286

Human exploration mission studies  

NASA Technical Reports Server (NTRS)

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.

Cataldo, Robert L.

1989-01-01

287

Multiband Superconductivity in Filled-Skutterudite Compounds (Pr1-xLax)Os4Sb12: An Sb Nuclear-Quadrupole-Resonance Study  

NASA Astrophysics Data System (ADS)

We report on the systematic evolution of normal-state properties and superconducting characteristics in filled-skutterudite compounds (Pr1-xLax)Os4Sb12 determined using Sb nuclear-quadrupole-resonance (NQR) experiments. The Sb-NQR spectra in these compounds have split into two sets, arising from different Sb12 cages containing either Pr or La, which enables us to measure two kinds of nuclear spin-lattice relaxation time T1Pr and T1La. In the normal state, the temperature (T) dependence of 1/T1PrT showed almost the same behavior as that for pure PrOs4Sb12 regardless of the increase in La content. In contrast, 1/T1LaT markedly decreases with increasing La concentration. These results show that 4 f2-derived magnetic fluctuations are almost localized at the Pr site. In the superconducting state for Pr-rich compounds of x=0.05 and 0.2, 1/T1Pr exponentially decreases down to T=0.7 K with no coherence peak below Tc as well as in PrOs4Sb12. A remarkable finding is that the residual density of states (RDOS) at the Fermi level below Tc is induced by La substitution for Pr. The impurity effect, usually observed in unconventional superconductors with a line-node gap, may not be the origin of the RDOS induced by the La substitution, since RDOS does not increase and Tc does not decrease with increasing La content. RDOS is more naturally explained if a small part (˜5.5%) of the total Fermi surface (FS) becomes gapless for x=0.05 and 0.2. These results are proposed to be understood in terms of a multiband-superconductivity (MBSC) model that assumes a full gap for part of the FS and the presence of point nodes for a small 4 f2-derived FS inherent in PrOs4Sb12. The former could be relevant with FS existing in LaOs4Sb12 and with the anisotropic gap with point nodes being markedly suppressed by either applying a magnetic field or substituting La for Pr. For La-rich compounds of x=0.8 and 1, on the other hand, 1/T1La exhibits a coherence peak and the nodeless energy gap characteristic for weak-coupling BCS s-wave superconductors. With increasing Pr content, Tc increases and the energy gap increases from 2?0/kBTc=3.45 for pure La compounds up to 2?0/kBTc=4.2 and 5.2 for the 60% Pr and 80% Pr compounds, respectively. The Pr substitution for La enhances the pairing interaction and induces an anisotropy in the energy-gap structure. The novel strong-coupling superconductivity in PrOs4Sb12 is inferred to be mediated by the local interaction between 4 f2-derived crystal-electric-field states with the electric quadrupole degree of freedom and conduction electrons. This coupling causes a mass enhancement of quasi-particles for a part of FS and induces a small FS, which is responsible for point nodes in the superconducting gap function. Note that the small FS does not play any primary role for the strong-coupling superconductivity in PrOs4Sb12.

Yogi, Mamoru; Nagai, Takayuki; Imamura, Yojyu; Mukuda, Hidekazu; Kitaoka, Yoshio; Kikuchi, Daisuke; Sugawara, Hitoshi; Aoki, Yuji; Sato, Hideyuki; Harima, Hisatomo

2006-12-01

288

[Phase I clinical study].  

PubMed

The main purpose of the phase I clinical study is to define the tolerable doses in each various administration schedules depend upon by careful clinical observations and by pharmaco-kinetic, -dynamic studies. final goal of the phase I clinical study is to establish the safe, most reasonable administration schedules to perform further clinical studies, including phase II, III and possibly iv. In addition, it is quite reasonable to observe efficacy of the given agent if possible. The patients who are selected to receive the phase I clinical study should be fulfilled the followings: (1) Histological proof of malignancy; (2) No best available therapy regimen at present; (3) Maintain reasonably well organ functions which are suitable to observe side reactions (4) No hang-over reactions from previous therapy and; (5) Consent from patient himself or members of the family concerning the study. The set-up of the initial administration dose should be established from mouse and dog preclinical studies. Retrospective studies revealed reasonably safe and efficient to start from the most sensitive dose in 1/5 LD10 of mouse or 1/5 TDL of dog on the mg square meter basis. Above method is widely used at present and it is a potential replacement for the large animal species as a routine procedure. Dose escalation routinely proceeded using a double dose escalation procedure or modified Fibonacci procedures with minimal risk. It is permitted to escalate administration dose in the same patient under careful considerations. The new agent which has enough reliable clinical date in the abroad, the clinical study in this country would be simplified. The phase I clinical study should be performed in the well-equipped institutions under the supervision of capable investigators. The guide line of phase I clinical study would be revised whenever it is necessary. PMID:6703717

Majima, H

1984-03-01

289

KET Social Studies Posters  

NSDL National Science Digital Library

The KET Social Studies posters provide an overview of the five “big ideas” that make up Kentucky’s K-12 social studies curriculum. These posters are appropriate for classroom display for both student and teacher reference. Each poster is available in two sizes and may be printed in color or black and white.

Ket

2012-02-15

290

Afro-Latin Studies  

Microsoft Academic Search

The state of Afro-Latin studies is reviewed, starting with questions about terminology and racial classification, then exploring issues of racism and the relation between race and class. The impact of black (and indigenous) social movements on the field of study is then examined and this raises the question of how ideologies and practices of mestizaje have changed in the wake

Peter Wade

2006-01-01

291

Social Studies Resource Units.  

ERIC Educational Resources Information Center

Based on the premise that fundamental solutions to environmental problems must include social solutions, these three resource units are designed to study the interrelation of man and nature as part of the social studies curriculum. A series of inquiry questions are posed with the intent of stimulating students to find solutions to our…

Bemiss, Clair W.

292

Cooperative Agreements Study Report.  

ERIC Educational Resources Information Center

During the 1983 meeting of the Florida Legislature, action was taken to begin a systematic study of the level of cooperation between the Florida public schools K-12 program and the community and junior colleges. The goals and objectives of the Cooperative Agreements Study were to review and compile a list of the cooperative agreements and identify…

Lawton, R. E.; Magruder, D.

293

1990 NACUBO Endowment Study.  

ERIC Educational Resources Information Center

The 1990 Endowment Study of America's colleges and universities covered a broad variety of endowment issues of concern to trustees and administrators. The survey was mailed to 450 institutions and 369 institutions (82%) responded. Results of the study showed that 367 institutions had endowment assets totaling $60.1 billion. For fiscal year 1990,…

National Association of College and University Business Officers, Washington, DC.

294

Interagency Depainting Study Status  

NASA Technical Reports Server (NTRS)

This document discusses coating removal in general. Sections of this presentation include: regulatory background, the initial parameters of the study, the current parameters of the study, stages in each sequence, preparation of the test specimen, material evaluation testing, chemical stripping, CO2 blasting, Flashjet coating removal, plastic media blasting, sodium bicarbonate wet stripping, water stripping, and wheat starch stripping.

Clark-Ingram, Marceia; Cook, Beth

1999-01-01

295

Lesson Study: Beyond Coaching  

ERIC Educational Resources Information Center

The authors assert that lesson study--a collaborative, teacher-led approach to learning from practice--offers a deeper, broader, more sustainable method of improving teacher practice than one-on-one coaching does. In lesson study, teachers and coaches of all levels of experience can work together, each bringing his or her own professional…

Lewis, Catherine; Perry, Rebecca; Foster, David; Hurd, Jacqueline; Fisher, Linda

2011-01-01

296

Women's and Gender Studies  

E-print Network

and interpretations of the roles of women and men in society, as well as analyze the multiple ways in which genderWomen's and Gender Studies #12;Women's and Gender Studies at Carleton University provides you with a unique and exciting opportunity to examine the diverse ways in which gender shapes our lives

Dawson, Jeff W.

297

Databases Improve Technical Studies  

ERIC Educational Resources Information Center

In Lower Saxony, technology studies as part of preparing technical education teachers for primary and partly for secondary education can be studied only at two universities--the Technical University of Brunswick and the University of Oldenburg. Technology education is not available at the Gymnasium (a type of secondary school leading to the…

Graube, Gabriele

2004-01-01

298

Cuban Studies Newsletter.  

ERIC Educational Resources Information Center

This is the first issue of the Cuban Studies Newsletter, a biannual publication designed to provide comprehensive and timely communication among those interested in Cuban Studies. The purpose of the newsletter stated in a recommendation by the International Conference on Cuban Bibliography and Acquisitions, April, 1970, is to promote the scholarly…

Pittsburgh Univ., PA. University Center for International Studies.

299

Home Study Advertising Handbook.  

ERIC Educational Resources Information Center

This handbook contains a collections of nine articles on the subject of direct-response advertising. The handbook gives advice on how to create effective advertisements for home study courses. The nine articles are the following: "Overview of Home Study Advertising in the 1990s" (Michael P. Lambert); "Ad Features that Sell" (Nancie E. Robertson);…

Lambert, Michael P., Ed.; Welch, Sally R., Ed.

300

Destination: Honduras. Study Guide.  

ERIC Educational Resources Information Center

This study guide was developed by the Peace Corps' Office of World Wise Schools. The aim of the guide is to promote better understanding of other people on the part of the people of the United States. Teachers can use the book to supplement the study of Central America or the environment. Using the materials, students will learn to: (1) identify…

Legowski, Margaret

301

Study Close-Out  

Cancer.gov

Step 4: Closing Out a Cancer Prevention Clinical Trial These documents are intended for the use of DCP Consorta staff conducting cancer chemoprevention studies under contract with NCI/DCP. SOP #2: Study Close-Out Responsibilities (SOP) (doc, 48kb) Lists

302

INTERNATIONAL STUDY CENTRE  

E-print Network

the BADER INTERNATIONAL STUDY CENTRE at Herstmonceux Castle 2015 #12;welcome to the Castle #12-Year 10 Arts at the BISC 11 Science at the BISC 12 Upper-Year 13 Summer at the BISC LIVE 14 FINANCE 17 17; The fact that the Bader International Study Centre operates within the walls of a fifteenthcentury English

Abolmaesumi, Purang

303

Contemporary China Studies  

E-print Network

Contemporary China Studies Postgraduate #12;Programme: Contemporary China Studies Postgraduate1 Chinese - Level 2 5 2 · Basic vocabulary & grammar Dealing with China: 3 1 Intercultural management · China's political constellation and its impact on business life · Human resources issues for China

Einmahl, Uwe

304

TOTAL DIET STUDY  

EPA Science Inventory

The Total Diet Study (TDS), sometimes called the Market Basket Study, is an ongoing FDA program that determines levels of various pesticide residues, contaminants, and nutrients in foods, for the purpose of estimating intakes of these substances in representative diets of specifi...

305

Methods of Studying Persons.  

ERIC Educational Resources Information Center

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…

Heinemann, Allen W.; Shontz, Franklin C.

306

Qualitative Studies in HRD.  

ERIC Educational Resources Information Center

The first of the four papers in this symposium, "What Is It Like To Be an Independent HRD Consultant?" (Alexander Ardishvili), reports on a phenomenological study that investigated the experience of being an independent HRD (human resource development) consultant through interviews with 10 successful HRD consultants. The study identified eight…

1999

307

MIXTURES FEASIBILITY STUDY  

EPA Science Inventory

A number of studies have been conducted to address questions concerning the toxicity of "real world" mixtures of DBPs. These studies, which used either concentrates of drinking water or humic acid preparations treated with various disinfectants, were largely negative and had a nu...

308

Hypothetical Reactor Accident Study  

E-print Network

- W 4 DfcSkoollo Rise-R-427 CARNSORE: Hypothetical Reactor Accident Study O. Walmod-Larsen, N. O: HYPOTHETICAL REACTOR ACCIDENT STUDY O. Walmod-Larsen, N.O. Jensen, L. Kristensen, A. Heide, K.L. Nedergård, P-basis accident and a series of hypothetical core-melt accidents to a 600 MWe reactor are de- scribed

309

SETDA Case Studies 2012  

ERIC Educational Resources Information Center

The State Educational Technology Directors Association (SETDA) published a series of case studies from 28 states to showcase examples of how ARRA EETT ("American Recovery and Reinvestment Act of 2009 Enhancing Education Through Technology") grant funds have impacted teaching and learning. SETDA collected data for the case studies through a variety…

State Educational Technology Directors Association, 2012

2012-01-01

310

Advanced planetary studies  

NASA Technical Reports Server (NTRS)

Results of planetary advanced studies and planning support are summarized. The scope of analyses includes cost estimation research, planetary mission performance, penetrator mission concepts for airless planets/satellites, geology orbiter payload adaptability, lunar mission performance, and advanced planning activities. Study reports and related publications are included in a bibliography section.

1976-01-01

311

Ontario Health Study (OHS)  

Cancer.gov

Launched in September 2010, the Ontario Health Study (OHS) is a prospective longitudinal cohort study. The OHS is an integrated platform for investigating the complex interplay of environmental, lifestyle and genetic components that increase individual and community risk of common adult diseases.

312

MATHEMATICS Program of Study  

E-print Network

MATHEMATICS Program of Study Degree Requirements The Department offers a program leading to the degree of Master of Arts in Mathematics. There are three "pathways" or tracks for advanced study in mathematics: pure, interdisciplinary, and statistics. All paths provide both thesis and non-thesis options

Thomas, Andrew

313

Renewable Electricity Futures Study  

E-print Network

Renewable Electricity Futures Study Executive Summary NREL is a national laboratory of the U for Sustainable Energy, LLC. Volume 2 PDF Volume 3 PDF Volume 1 PDF Volume 4 PDF #12;Renewable Electricity Futures. National Renewable Energy Laboratory Suggested Citations Renewable Electricity Futures Study (Entire Report

314

Energy conversion alternatives study  

NASA Technical Reports Server (NTRS)

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.

Shure, L. T.

1979-01-01

315

Fluctuation studies in STAR  

E-print Network

Study of event by event fluctuations of thermodynamic quantities offer us more insight about the hot and dense matter created in the relativistic heavy ion collisions. In this review the recent results on these studies carried out by the STAR collaboration are presented.

Supriya Das

2006-12-08

316

COLD WEATHER PLUME STUDY  

EPA Science Inventory

While many studies of power plant plume transport and transformation have been performed during the summer, few studies of these processes during the winter have been carried out. Accordingly, the U.S. Environmental Protection Agency and the Electric Power Research Institute join...

317

Women's Studies Librarian  

NSDL National Science Digital Library

The University of Wisconsin System Women's Studies Librarian offers a web page that provides exhaustive lists of bibliographies of monographs and scholarly articles in women's studies. The site also offers core lists of women's studies books in print on subjects from aging to women of color, compiled by the Association of College and Research Libraries Women's Studies Section. These core lists are intended to aid librarians in building women's collections, as well as guide teaching faculty in selecting course materials. Publishers and prices are provided. The page also points to selected women's Internet subject resources, e-zines and newsletters, and syllabi and course materials. http://www.library.wisc.edu/libraries/WomensStudies/

318

BBC Prison Study  

NSDL National Science Digital Library

The official website for the BBC Prison Study, that accompanies the groundbreaking 2002 BBC Prison Study broadcast, went online in September 2008. The Prison Study put volunteers in a prison-style setting and then filmed them. The purpose of the experiment, conducted by British researchers, was to see how relationships evolved in places such as prisons, as well as in other institutions where unequal power exists, such as schools, barracks, and offices. What they found "changed our basic understanding of how groups and power work"; the study showed when and why people accept or challenge unequal power in groups. Visitors should click on "View The Movie Map", which is in the top left hand corner of the webpage, to see a menu of movie clips of different situations at the prison. The clips explore such situations as "Food Inequalities" to "Prisoners Mobilize Against Guards" to "The Emergence of a New Guard Regime". The menu in the upper left hand corner of the web page has a link to "Activities" which will prove especially useful for educators. The Activities link is further divided into the following sections, "Discussion Questions", "Exercises", and "Psychometric Tests". Each of these sections allows for more in-depth study of the issues raised by the Prison Study. The Psychometric Tests are those given to the volunteers in the study, and can be taken by visitors to the site and compared to the volunteers' scores. The "Resources" link, in the menu in the upper left hand corner of the webpage, includes hypertext links to "Scientific Publications", "Quantitative Data", and a "Glossary", that provide, respectively, a number of full-text articles about the Prison Study that have been published, the data collected during the study, and definitions of psychological terms used in the study.

2008-01-01

319

National Election Studies  

NSDL National Science Digital Library

In this season of electoral uncertainty, both researchers and concerned citizens can find the extensive data available at the National Election Studies Website quite useful. "NES conducts national surveys of the American electorate in presidential and midterm election years and carries out research and development work through pilot studies in odd-numbered years. The NES time-series now encompasses 23 biennial election studies spanning five decades." The data from these studies, along with codebooks, cover public opinion and political participation themes such as "expectations about the election outcome; perceptions and evaluations of the major parties and their candidates; interest in the campaign; information about politics; partisanship; assessments of the relative importance of major problems facing the country; attention to campaign coverage in the mass media; feelings of political efficacy; political values; conservatism vs. liberalism; trust in government; political participation; vote choice; economic well-being; positions on social welfare, economic, social, and civil rights issues" and more. Pilot studies, whose data is also available on-site, are conducted in off-election years in order "to test new, or refine existing, instrumentation and study designs." A major feature of the site, useful to not only researchers but journalists and the general public, is The NES Guide to Public Opinion and Electoral Behavior, which offers easily digestible data on a whole range of issues drawn from the time-series studies.

320

Materials Failure Case Studies  

NSDL National Science Digital Library

This website offers innovative course materials for teaching engineering design and analysis through failure case studies, supporting the integration of research in forensic engineering into undergraduate education. The site includes an introduction to the overall project and a bibliography as well as typical civil engineering and engineering mechanics courses, with over 50 case studies currently listed. This web site is a companion to the book Beyond Failure: Forensic Case Studies for Civil Engineers, Delatte, Norbert J., ASCE Press. The site is a living document that will supplement the book with web links, additional information, and supplemental illustrations. At this time, not all of the cases have been filled in yet.

Delatte, Norbert J., Jr.

2008-12-12

321

Tokamak reactor studies  

SciTech Connect

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.

Baker, C.C.

1981-01-01

322

Studying aging in Drosophila.  

PubMed

Drosophila melanogaster represents one of the most important genetically accessible model organisms for aging research. Studies in flies have identified single gene mutations that influence lifespan and have characterized endocrine signaling interactions that control homeostasis systemically. Recent studies have focused on the effects of aging on specific tissues and physiological processes, providing a comprehensive picture of age-related tissue dysfunction and the loss of systemic homeostasis. Here we review methodological aspects of this work and highlight technical considerations when using Drosophila to study aging and age-related diseases. PMID:24751824

He, Ying; Jasper, Heinrich

2014-06-15

323

Recent Advances in the 5f-Relevant Electronic States and Unconventional Superconductivity of Actinide Compounds  

NASA Astrophysics Data System (ADS)

Recent advances in the understanding of the 5f-relevant electronic states and unconventional superconducting properties are reviewed in actinide compounds of UPd2Al3, UPt3, URu2Si2, UGe2, and PuRhGa5. These are based on the experimental results carried out on high-quality single crystal samples, including transuranium compounds, which were grown by using combined techniques. The paring state and the gap structure of these superconductors are discussed, especially for the corresponding Fermi surfaces which were clarified by the de Haas-van Alphen experiment and the energy band calculations. A detailed systematic study using the NQR/NMR spectroscopy reveals the d-wave superconductivity in PhRhGa5 and the difference of magnetic excitations due to the difference of ground states in U-, Np-, and Pu-based AnTGa5 (T: transition metal) compounds.

Haga, Yoshinori; Sakai, Hironori; Kambe, Shinsaku

2007-05-01

324

Molecular structure and nuclear quadrupole coupling tensors of 14N and 35Cl in 1-chloro-2,4-dinitrobenzene. Phase I  

Microsoft Academic Search

The crystal structure of the orthorhombic, stable phase of 1-chloro-2,4-dinitrobenzene was studied at T=295 K by x-ray diffraction; space group D102h=Pccn; a=893.0(1) pm, b=1104.5(2) pm, c=1567.6(2) pm, Z=8, &rgr;calc=1.740 Mg m?3, all atoms in position 8(e). The Zeeman split single crystal 35Cl NQR gives e2&Fgr;zzQh?1(35Cl)=74.287(4) MHz, &eegr;(35Cl)=0.1636(18) at T=295 K. At 110 K the values are: e2&Fgr;zzQh?1(35Cl)=75.183(4) MHz, &eegr;(35Cl)=0.1572(20). &Fgr;zz(35Cl)

Surendra Sharma; Norbert Weiden; Alarich Weiss

1989-01-01

325

High-temperature protonic motion and low-temperature lattice deformation in one-dimensional hydrogen-bonded molecular chain in tetramethylpyrazine-chloranilic acid (1?1)  

NASA Astrophysics Data System (ADS)

The phase transition of tetramethylpyrazine-chloranilic acid (1?1) was studied by 35Cl NQR measurements. The frequency splits into a doublet below T c=83.0 ± 0.5 K. The averaged frequency of 36.98 MHz at 77 K suggests an electrically neutral electronic state of the chloranilic acid molecule, that is, no proton transfer between the acid and base molecules. An enhancement of the relaxation rate was observed at T c: it is presumably due to critical slowing down of a hydrogen motion in the one-dimensional hydrogen bond network. The excitation of a high-temperature hydrogen motion at T > 250 K is also suggested by the steep decrease of T 1 observed above 250 K. From the slope of the Arrhenius plots, an activation energy of 35 kJ mol- is calculated for the motion.

Asaji, Tetsuo; Yoshimura, Yusuke; Amino, Daiki

326

High-temperature protonic motion and low-temperature lattice deformation in one-dimensional hydrogen-bonded molecular chain in tetramethylpyrazine chloranilic acid (1:1)  

NASA Astrophysics Data System (ADS)

The phase transition of tetramethylpyrazine chloranilic acid (1:1) was studied by 35Cl NQR measurements. The frequency splits into a doublet below T c = 83.0 ± 0.5 K. The averaged frequency of 36.98 MHz at 77 K suggests an electrically neutral electronic state of the chloranilic acid molecule, that is, no proton transfer between the acid and base molecules. An enhancement of the relaxation rate was observed at T c: it is presumably due to critical slowing down of a hydrogen motion in the one-dimensional hydrogen bond network. The excitation of a high-temperature hydrogen motion at T > 250 K is also suggested by the steep decrease of T 1 observed above 250 K. From the slope of the Arrhenius plots, an activation energy of 35 kJ mol - 1 is calculated for the motion.

Asaji, Tetsuo; Yoshimura, Yusuke; Amino, Daiki

2007-09-01

327

Spin Freezing and Recovery of Sublattice Magnetization in Lightly Doped Lanthanum Cuprate  

SciTech Connect

{sup 139}La NQR studies in lightly doped La{sub 2}Cu{sub 1-x}Li{sub x}O{sub 4} and La{sub 1.8-x}Eu{sub 0.2}Sr{sub x}CuO{sub 4} are reviewed. A strong enhancement of the {sup 139}La relaxation rate with a peak accompanied by a sudden increase of the local field at low T has been observed similarly to La{sub 2-x}Sr{sub x}CuO{sub 4}. The anomalous magnetic properties are discussed in the light of the microscopic segregation of doped holes into hole-rich domain walls separating undoped AF domains.

Suh, B.J.; Hammel, P.C.; Sarrao, J.L.; Thompson, J.D.; Fisk, Z.; Hucker, M.; Buchner, B.

1998-10-24

328

Brazilian Sepsis Epidemiological Study (BASES study)  

PubMed Central

Introduction Consistent data about the incidence and outcome of sepsis in Latin American intensive care units (ICUs), including Brazil, are lacking. This study was designed to verify the actual incidence density and outcome of sepsis in Brazilian ICUs. We also assessed the association between the Consensus Conference criteria and outcome Methods This is a multicenter observational cohort study performed in five private and public, mixed ICUs from two different regions of Brazil. We prospectively followed 1383 adult patients consecutively admitted to those ICUs from May 2001 to January 2002, until their discharge, 28th day of stay, or death. For all patients we collected the following data at ICU admission: age, gender, hospital and ICU admission diagnosis, APACHE II score, and associated underlying diseases. During the following days, we looked for systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis, and septic shock criteria, as well as recording the sequential organ failure assessment score. Infection was diagnosed according to CDC criteria for nosocomial infection, and for community-acquired infection, clinical, radiological and microbiological parameters were used. Results For the whole cohort, median age was 65.2 years (49–76), median length of stay was 2 days (1–6), and the overall 28-day mortality rate was 21.8%. Considering 1383 patients, the incidence density rates for sepsis, severe sepsis and septic shock were 61.4, 35.6 and 30.0 per 1000 patient-days, respectively. The mortality rate of patients with SIRS, sepsis, severe sepsis and septic shock increased progressively from 24.3% to 34.7%, 47.3% and 52.2%, respectively. For patients with SIRS without infection the mortality rate was 11.3%. The main source of infection was lung/respiratory tract. Conclusion Our preliminary data suggest that sepsis is a major public health problem in Brazilian ICUs, with an incidence density about 57 per 1000 patient-days. Moreover, there was a close association between ACCP/SCCM categories and mortality rate. PMID:15312226

Silva, Eliézer; Pedro, Marcelo de Almeida; Sogayar, Ana Cristina Beltrami; Mohovic, Tatiana; Silva, Carla Lika de Oliveira; Janiszewski, Mariano; Cal, Ruy Guilherme Rodrigues; de Sousa, Érica Fernandes; Abe, Thereza Phitoe; de Andrade, Joel; de Matos, Jorge Dias; Rezende, Ederlon; Assunção, Murillo; Avezum, Álvaro; Rocha, Patrícia CS; de Matos, Gustavo Faissol Janot; Bento, André Moreira; Corrêa, Alice Danielli; Vieira, Paulo Cesar Bastos; Knobel, Elias

2004-01-01

329

Videofluoroscopic Swallowing Study (VFSS)  

MedlinePLUS

... hear are: videofluoroscopic swallowing study, or videofluoroscopy modified barium swallow, or MBS esophagram cookie swallow The American ... give you different foods and drinks mixed with barium. The barium makes the food and liquid show ...

330

Teleoperator human factors study  

NASA Technical Reports Server (NTRS)

The progress made on the Teleoperator Human Factors Study program is summarized. Technical and programmatic problems that were encountered were discussed along with planned activities. The report contains four sections: Work Performed, Future Work, Problems Encountered, and Cost Information

1984-01-01

331

Teleoperator human factors study  

NASA Technical Reports Server (NTRS)

The progress made on the Teleoperator Human Factors Study program is summarized. Technical and programmatic problems that were encountered are discussed along with planned activity. Work performed, future work, problems encountered, and cost information comprise the topics addressed herein.

1984-01-01

332

Cancers Selected for Study  

Cancer.gov

The Cancer Genome Atlas researchers are mapping the genetic changes in 20 cancers. Find out which cancers have been selected for study, the criteria for selection and the scientific questions being asked about each cancer.

333

Political Studies Review  

NSDL National Science Digital Library

Sponsored by the Political Studies Association, the Political Studies Review was designed to �develop and promote the study of politics.� In particular, the editors of the Political Studies Review strive to create a space in which �new and exciting approaches to reviewing the discipline� of political science arise. The site is a great source for anyone interested in politics and is the leading source for political science book reviews in English. New reviews are regularly updated on recent materials. Not only does the site provide means to update your knowledge of recent political literature, but it is also useful to those considering publishing, as the editors consider a wide array of opinions and ideas.

Festenstein, Matthew; Smith, Martin

2006-11-11

334

Accelerator research studies  

SciTech Connect

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.

Not Available

1992-01-01

335

NCCCP: Comparative Case Studies  

Cancer.gov

For the case studies, RTI will conduct site visits during each of the three years of program implementation to obtain in-depth information about aspects of each program's design, development, and implementation.

336

Rotorcraft convertible engine study  

NASA Technical Reports Server (NTRS)

The objective of the Rotorcraft Convertible Engine Study was to define future research and technology effort required for commercial development by 1988 of convertible fan/shaft gas turbine engines for unconventional rotorcraft transports. Two rotorcraft and their respective missions were defined: a Fold Tilt Rotor aircraft and an Advancing Blade Concept (ABC) rotorcraft. Sensitivity studies were conducted with these rotorcraft to determine parametrically the influence of propulsion characteristics on aircraft size, mission fuel requirements, and direct operating costs (DOC). The two rotorcraft were flown with conventional propulsion systems (separate lift/cruise engines) and with convertible propulsion systems to determine the benefits to be derived from convertible engines. Trade-off studies were conducted to determine the optimum engine cycle and staging arrangement for a convertible engine. Advanced technology options applicable to convertible engines were studied. Research and technology programs were identified which would ensure technology readiness for commercial development of convertible engines by 1988.

Gill, J. C.; Earle, R. V.; Mar, H. M.

1982-01-01

337

MULTIPLE CONTAMINANTS CASE STUDIES  

EPA Science Inventory

The presentation provides information taken from the arsenic demonstration program projects that have treatment systems removing multiply contaminants from drinking water. The case studies sited in the presentation consist of projects that have arsenic along with either nitrate, ...

338

Genetic and Molecular Studies  

Cancer.gov

DCEG strives to understand the interplay of molecular and genetic effects and radiation on cancer etiology. This type of work involves biological samples and high-quality dosimetry or other exposure assessment.Examples of such studies include:Childhood

339

HYDROGEOLOGIC CASE STUDIES  

EPA Science Inventory

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...

340

Tethered gravity laboratories study  

NASA Technical Reports Server (NTRS)

Variable Gravity Laboratory studies are discussed. The following subject areas are covered: (1) conceptual design and engineering analysis; (2) control strategies (fast crawling maneuvers, main perturbations and their effect upon the acceleration level); and (3) technology requirements.

Lucchetti, F.

1989-01-01

341

Comparative Packaging Study  

NASA Technical Reports Server (NTRS)

This viewgraph presentation describes a comparative packaging study for use on long duration space missions. The topics include: 1) Purpose; 2) Deliverables; 3) Food Sample Selection; 4) Experimental Design Matrix; 5) Permeation Rate Comparison; and 6) Packaging Material Information.

Perchonok, Michele; Antonini, David

2008-01-01

342

Methods of Studying Persons.  

ERIC Educational Resources Information Center

Describes a method that permits answering research questions of general importance by examining individuals in a comprehensive, whole-person manner. Discusses their use in two studies of persons with spinal cord injuries. (LLL)

Heinemann, Allen W.; Shontz, Franklin C.

1985-01-01

343

Earth study from space  

NASA Technical Reports Server (NTRS)

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.

Sidorenko, A. V.

1981-01-01

344

Schoolground Soil Studies.  

ERIC Educational Resources Information Center

Outlined are simple activities for studying soil, which can be conducted in the schoolyard. Concepts include soil profiles, topsoil, soil sizes, making soil, erosion, slope, and water absorption. (SJL)

Doyle, Charles

1978-01-01

345

LANL Studies Earth's Magnetosphere  

ScienceCinema

A new 3-D supercomputer model presents a new theory of how magnetic reconnection works in high-temperature plasmas. This Los Alamos National Laboratory research supports an upcoming NASA mission to study Earth's magnetosphere in greater detail than ever.

Daughton, Bill

2014-08-12

346

ADVANCED CUTTINGS TRANSPORT STUDY  

SciTech Connect

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.

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

347

LIMB PROCESS DEVELOPMENT STUDIES  

EPA Science Inventory

The report covers basic and applied studies concerned with three Limestone Injection Multistage Burner (LIMB) process objectives: (1) avoiding degradation of collection efficiency in the electrostatic precipitator (ESP) during LIMB, (2) achieving satisfactory sulfur dioxide (SO2)...

348

Graduate Studies Construction Engineering  

E-print Network

funded by the National Science Foundation (NSF), Construction Industry Institute (CII), Georgia engineering, building construction, and industrial and systems engineering. SELECTED COURSES · ConstructionGraduate Studies Construction Engineering CONSTRUCTION ENGINEERING The construction engineering

Jacobs, Laurence J.

349

Operator Certification Study Guide.  

ERIC Educational Resources Information Center

This study guide contains typical questions and answers that all levels of water treatment plant operators might expect to find on a certification examination. The manual covers the basic sciences, treatment techniques, testing procedures, and federal legislation. (Author/SB)

American Water Works Association, Denver, CO.

350

LANL Studies Earth's Magnetosphere  

SciTech Connect

A new 3-D supercomputer model presents a new theory of how magnetic reconnection works in high-temperature plasmas. This Los Alamos National Laboratory research supports an upcoming NASA mission to study Earth's magnetosphere in greater detail than ever.

Daughton, Bill

2011-04-15

351

Studying Eco Climatic Domains  

NSDL National Science Digital Library

Activity is a Project BudBurst/National Ecological Observatory Network (NEON) exploration of eco-climactic domains, as defined by NEON, by investigating characteristics of a specific domain and studying two representative plants in that domain.

Neon; Budburst, Project

352

National Children's Study  

MedlinePLUS

... the Director of NICHD to NCS Participants in Spanish Here is the Spanish version of the letter to all Vanguard Study ... to NCS Participants Letter to NCS Participants in Spanish View All Slides What is the National Children's ...

353

Studies in Aeolian geology  

NASA Technical Reports Server (NTRS)

The objective of the research was to assess the significance of aeolian (windblown) processes in the evolution of planetary surfaces. The approach was to use wind tunnel simulations, field studies of possible analogs, and analyses of spacecraft data.

Greeley, Ronald

1988-01-01

354

Banner Ad Placement Study  

NSDL National Science Digital Library

Webreference.com (discussed in the April 19, 1996 Scout Report) has recently added this interesting and thought-provoking resource to its site. The resource presents the results of a study of banner ad placement at webreference.com, conducted between March 25 and April 15, 1997 by three University of Michigan School of Business Administration students. The study concludes that changes in placement of banner ads affects "click-through" rates.

Doyle, Kim.; Minor, Anastasia.; Weyrich, Carolyn.

1997-01-01

355

Vitrification melter study  

SciTech Connect

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.

Jones, J.A.

1995-04-01

356

Concrete containment aging study  

SciTech Connect

In 1989, IAEA initiated a pilot study on the management of aging of nuclear power plant components. The Phase I and II studies of concrete containment are discussed. With the data base, plant owners will be able to review and enhance their existing programs. IAEA will analyze data provided by participating plants and the report is scheduled to be released by late 1994 (final report release mid-1995).

Pachner, J. [International Atomic Energy Agency, Vienna (Austria); Tai, T.M. [Bechtel National, Inc., Oak Ridge, TN (United States); Naus, D. [Oak Ridge National Lab., TN (United States)

1994-04-01

357

Paired watershed study design  

SciTech Connect

The purpose of the fact sheet is to describe the paired watershed approach for conducting nonpoint source (NPS) water quality studies. The basic approach requires a minimum of two watersheds - control and treatment - and two periods of study - calibration and treatment. The basis of the paired watershed approach is that there is a quantifiable relationship between paired water quality data for the two watersheds, and that this relationship is valid until a major change is made in one of the watersheds.

Clausen, J.C.; Spooner, J.

1993-09-01

358

Advanced planetary studies  

NASA Technical Reports Server (NTRS)

Results of planetary advanced studies and planning support provided by Science Applications, Inc. staff members to Earth and Planetary Exploration Division, OSSA/NASA, for the period 1 February 1981 to 30 April 1982 are summarized. The scope of analyses includes cost estimation, planetary missions performance, solar system exploration committee support, Mars program planning, Galilean satellite mission concepts, and advanced propulsion data base. The work covers 80 man-months of research. Study reports and related publications are included in a bibliography section.

1982-01-01

359

Genome Wide Association Studies  

Microsoft Academic Search

\\u000a The availability of high throughput technology for parallel genotyping has opened the field of genetics to genome-wide association\\u000a studies (GWAS). These studies generate massive amount of genetic data that challenge investigators with issues related to\\u000a data management, statistical analysis of large data sets, visualization, and annotation of results. We will review the common\\u000a approach to analysis of GWAS data and

Paola Sebastiani; Nadia Solovieff

2011-01-01

360

FILM STUDIES CURRICULUM COMMITTEE  

E-print Network

RTH 36000. CONTEMpORaRY aRT CMLT 22200. CLaSSICaL TRaDITION IN MODERN DRaMa, FICTION, aND FILM [W, AH] COMM-CENTURY BRITISH NOvEL ON FILM [AH] FREN 32900. STUDIES IN THE TWENTIETH-CENTURY: FICTION aND FILM (in French) [CFILM STUDIES CURRICULUM COMMITTEE: Debra Shostak, Chair Ahmet Atay (Communication) Carolyn Durham

Wilson, Mark A.

361

Constellation Commodities Studies Summary  

NASA Technical Reports Server (NTRS)

Constellation program was NASA's long-term program for space exploration. The goal of the commodities studies was to solicit industry expertise in production, storage, and transportation required for future use and to improve efficiency and life cycle cost over legacy methods. Objectives were to consolidate KSC, CCAFS and other requirements; extract available industry expertise; identify commercial opportunities; and establish synergy with State of Florida partnerships. Study results are reviewed.

Dirschka, Eric

2011-01-01

362

Power subsystem automation study  

NASA Technical Reports Server (NTRS)

The purpose of the phase 2 of the power subsystem automation study was to demonstrate the feasibility of using computer software to manage an aspect of the electrical power subsystem on a space station. The state of the art in expert systems software was investigated in this study. This effort resulted in the demonstration of prototype expert system software for managing one aspect of a simulated space station power subsystem.

Tietz, J. C.; Sewy, D.; Pickering, C.; Sauers, R.

1984-01-01

363

Undergraduate General Studies Degree  

E-print Network

.ius.edu/ContinuingStudies Saundra Gordon, Manager-Credit Programs gordonse@ius.edu Richmond Indiana University East 2325 Chester.iupuc.edu/academics/programs/generalstudies.asp Vickie Welsh-Huston, General Studies Director vwelshhu@iupuc.edu Fort Wayne Indiana University­Purdue University Fort Wayne Kettler Hall 145 · 2101 Coliseum Blvd. East Fort Wayne, IN 46805-1499 Phone: 260

Polly, David

364

14 N quadrupole resonance and 1 H T 1 dispersion in the explosive RDX  

NASA Astrophysics Data System (ADS)

The explosive hexahydro-1,3,5-trinitro-s-triazine (CH 2-N-NO 2) 3, commonly known as RDX, has been studied by 14N NQR and 1H NMR. NQR frequencies and relaxation times for the three ?+ and ?- lines of the ring 14N nuclei have been measured over the temperature range 230-330 K. The 1H NMR T1 dispersion has been measured for magnetic fields corresponding to the 1H NMR frequency range of 0-5.4 MHz. The results have been interpreted as due to hindered rotation of the NO 2 group about the N-NO 2 bond with an activation energy close to 92 kJ mol -1. Three dips in the 1H NMR dispersion near 120, 390 and 510 kHz are assigned to the ?0, ?- and ?+ transitions of the 14NO 2 group. The temperature dependence of the inverse line-width parameters T2? of the three ?+ and ?- ring nitrogen transitions between 230 and 320 K can be explained by a distribution in the torsional oscillational amplitudes of the NO 2 group about the N-NO 2 bond at crystal defects whose values are consistent with the latter being mainly edge dislocations or impurities in the samples studied. Above 310 K, the 14N line widths are dominated by the rapid decrease in the spin-spin relaxation time T2 due to hindered rotation of the NO 2 group. A consequence of this is that above this temperature, the 1H T1 values at the quadrupole dips are dominated by the spin mixing time between the 1H Zeeman levels and the combined 1H and 14N spin-spin levels.

Smith, John A. S.; Blanz, Martin; Rayner, Timothy J.; Rowe, Michael D.; Bedford, Simon; Althoefer, Kaspar

2011-12-01

365

14N quadrupole resonance and 1H T1 dispersion in the explosive RDX.  

PubMed

The explosive hexahydro-1,3,5-trinitro-s-triazine (CH2-N-NO2)3, commonly known as RDX, has been studied by 14N NQR and 1H NMR. NQR frequencies and relaxation times for the three ?+ and ?- lines of the ring 14N nuclei have been measured over the temperature range 230-330 K. The 1H NMR T1 dispersion has been measured for magnetic fields corresponding to the 1H NMR frequency range of 0-5.4 M Hz. The results have been interpreted as due to hindered rotation of the NO2 group about the N-NO2 bond with an activation energy close to 92 kJ mol(-1). Three dips in the 1H NMR dispersion near 120, 390 and 510 kHz are assigned to the ?0, ?- and ?+ transitions of the 14NO2 group. The temperature dependence of the inverse line-width parameters T2? of the three ?+ and ?- ring nitrogen transitions between 230 and 320 K can be explained by a distribution in the torsional oscillational amplitudes of the NO2 group about the N-NO2 bond at crystal defects whose values are consistent with the latter being mainly edge dislocations or impurities in the samples studied. Above 310 K, the 14N line widths are dominated by the rapid decrease in the spin-spin relaxation time T2 due to hindered rotation of the NO2 group. A consequence of this is that above this temperature, the 1H T1 values at the quadrupole dips are dominated by the spin mixing time between the 1H Zeeman levels and the combined 1H and 14N spin-spin levels. PMID:21978662

Smith, John A S; Blanz, Martin; Rayner, Timothy J; Rowe, Michael D; Bedford, Simon; Althoefer, Kaspar

2011-12-01

366

Wilson Cycle studies  

NASA Technical Reports Server (NTRS)

The main activity relating to the study during this half year was a three week field trip to study Chinese sedimentary basins (June 10 to July 3, 1986) at no cost to the project. This study, while of a reconnaissance character, permitted progress in understanding how the processes of island arc-collision and micro-continental collision operated during the Paleozoic in far western China (especially the Junggar and Tarim basins and in the intervening Tien Shan Mountains). These effects of the continuing collision of India and Asia on the area were also studied. Most specifically, these result in the elevation of the Tien Shan to more than 4 km above sea level and the depression of Turfan to move 150m below sea level. Both thrusting and large-scale strike-slip motion are important in producing these elevation changes. Some effort during the half year was also devoted to the study of greenstone-belts in terms of the Wilson Cycle.

Burke, Kevin

1987-01-01

367

ADVANCED CUTTINGS TRANSPORT STUDY  

SciTech Connect

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.

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

368

Cosmos-1989 immunology studies  

NASA Technical Reports Server (NTRS)

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.

Sonnenfeld, Gerald

1991-01-01

369

Laboratory microfusion capability study  

NASA Astrophysics Data System (ADS)

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 2 study are described in the present report.

1993-05-01

370

Laboratory microfusion capability study  

SciTech Connect

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.

Not Available

1993-05-01

371

PN PQ Folios Quiet Study  

E-print Network

08.29.2014 FLOOR 5 Stairs E E A B DDEGH H EG K L N PA PN PN PQ Folios A­PQ 550A Quiet Study Spaces Study Spaces Study Spaces Study Spaces 550B Quiet Study Spaces M NX P F FLOOR 5 Stairs E E Classroom A B DDEGH H EG K L N PA PN PN PQ Folios A­PQ 550A Quiet Study Spaces Study Spaces Study Spaces Study Spaces

Walker, Matthew P.

372

Parylene C Aging Studies.  

SciTech Connect

Parylene C is used in a device because of its conformable deposition and other advantages. Techniques to study Parylene C aging were developed, and %22lessons learned%22 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 (~40 days) aging experiments with free standing and ceramic-supported Parylene C films highlighted %22lessons learned%22 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 (%22necking%22) for robust accelerated aging of Parylene C.

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

2014-09-01

373

REP Concept Feasibility Study  

NASA Technical Reports Server (NTRS)

Radioisotope Electric Propulsion (REP) may have the potential to provide certain advantages, over conventional chemical propulsion, for outer planetary exploration involving small bodies and long term investigations for medium class missions requiring power comparable to past outer planetary exploration missions. This paper describes a study that investigates the concept s feasibility by performing a preliminary conceptual design of an REP-based spacecraft for a design reference mission. The mission utilizes a spacecraft with a radioisotope power supply less than one kilowatt while operating for a minimum of 10-years. A key element of the REP spacecraft is to ensure sustained science return by orbiting or flying in formation with selected targets. Utilizing current and impending technological advances, this study finds that at a conceptual design level a small body REP orbiter/explorer appears to be feasible for the design reference mission selected for this study.

Edwards, Daryl A.; Ensworth, Clinton B. F.; Goodnight, Thomas W.; Sheehe, Charles J.; Wiersma, Stephen C.; Adamsen, Paul B., II; Frank, Larry

2004-01-01

374

STUDIES ON EXPERIMENTAL HYPERTENSION  

PubMed Central

1. Extraction of finely ground fresh hog kidney with distilled water adjusted to pH 7.8 with sodium hydroxide, followed by successive treatment, as described, with trichloroacetic acid and acetone, gives renin in good yield of a purity suitable for physiological studies and a good starting material for further purification. It contains 15 dog units per mg. N. 2. Further successive purification of this material with ethyl alcohol and ammonium sulfate gives a preparation containing 130 dog units per mg. N. The purest preparation hitherto reported (15) contained 16.0 to 20.8 units per mg. N. Preliminary Tiselius electrophoresis studies suggest homogeneity, but further studies to establish purity are in progress. 3. The properties of the most purified renin indicate that it is a protein. Its chemical and physiological properties correspond to those of the material in crude renal extract which induces an elevation of blood pressure when it is injected intravenously. PMID:19871310

Katz, Yale J.; Goldblatt, Harry

1943-01-01

375

Cosmos: 1989 immunology studies  

NASA Technical Reports Server (NTRS)

The effects of flight on Cosmos mission 2044 on leukocyte subset distribution and the sensitivity of bone marrow cells to colony stimulating factor-GM were determined. A parallel study with antiorthostatic suspension was also carried out. The study involved repetition and expansion of studies performed on Cosmos 1887. Spleen and bone marrow cells were obtained from flown, vivarium control, synchronous control, and suspended rats. The cells were stained with a series of monoclonal antibodies directed against rat leukocyte cell surface antigens. Control cells were stained with a monoclonal antibody directed against an irrelevant species or were unstained. Cells were then analyzed for fluorescence using a FACSCAN flow cytometer. Bone marrow cells were placed in culture with GM-CSF in McCoy's 5a medium and incubated for 5 days. Cultures were then evaluated for the number of colonies of 50 cells or greater.

Sonnenfeld, Gerald

1991-01-01

376

Why study treatment outcome?  

PubMed

Concern about the spiraling cost of mental health care has increased the need for reliable data about the outcomes of such care. Treatment outcome studies, although difficult to design and carry out, are essential in demonstrating the efficacy of psychiatric treatment, rationalizing clinical decision making, and encouraging public support for the availability of appropriate, cost-effective care for the mentally ill. Ideally, outcome studies should focus not only on clinical symptomatology but also on patients' social, interpersonal, and occupational adjustment as well as on factors that, taken together, shape the quality of life. The authors discuss these issues and some of the impediments to collecting useful outcome data, including the complexity of the mental health service delivery system and problems related to patient selection, study design, and how treatment is defined. PMID:1959890

Mirin, S M; Namerow, M J

1991-10-01

377

Black Hills hydrology study  

USGS Publications Warehouse

The Black Hills area of western South Dakota is a valuable resource center. The area has attracted numerous residents and industries because of the availability of mineral, timber, agricultural, recreational, and water resources. The water resources of the area have been stressed locally by increasing population, periodic drought, and development of other resources. In response to residents' concerns about these stresses on the water resources, the Black Hills Hydrology Study was initiated in 1990 as a cooperative effort among the U.S. Geological Survey, the South Dakota Department of Environment and Natural Resources, and the West Dakota Water Development District. West Dakota represents the various local and county cooperators. This report describes the purpose, scope, approach, and status of the study and presents highlights from the first project data report produced for the study.

Driscoll, D.G.

1994-01-01

378

Optimal symmetric flight studies  

NASA Technical Reports Server (NTRS)

Several topics in optimal symmetric flight of airbreathing vehicles are examined. In one study, an approximation scheme designed for onboard real-time energy management of climb-dash is developed and calculations for a high-performance aircraft presented. In another, a vehicle model intermediate in complexity between energy and point-mass models is explored and some quirks in optimal flight characteristics peculiar to the model uncovered. In yet another study, energy-modelling procedures are re-examined with a view to stretching the range of validity of zeroth-order approximation by special choice of state variables. In a final study, time-fuel tradeoffs in cruise-dash are examined for the consequences of nonconvexities appearing in the classical steady cruise-dash model. Two appendices provide retrospective looks at two early publications on energy modelling and related optimal control theory.

Weston, A. R.; Menon, P. K. A.; Bilimoria, K. D.; Cliff, E. M.; Kelley, H. J.

1985-01-01

379

Seal design alternatives study  

SciTech Connect

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.

Van Sambeek, L.L. [RE/SPEC Inc., Rapid City, SD (US); Luo, D.D.; Lin, M.S.; Ostrowski, W.; Oyenuga, D. [Parsons Brinckerhoff Quade & Douglas, Inc., San Francisco, CA (US)

1993-06-01

380

Work Study Program Procedure Manual  

E-print Network

Work Study Program Procedure Manual Prepared by: Student Financial Services, Office..............................................................................................................2 Responsibilities of the Work Study Supervisor.....................................................6 Responsibilities of the Work Study Administrator...............................................7

Sinnamon, Gordon J.

381

Work Study Program Procedure Manual  

E-print Network

Work Study Program Procedure Manual Prepared by: Student Financial Services, Office..............................................................................................................2 Responsibilities of the Work Study Supervisor.....................................................5 Responsibilities of the Work Study Administrator...............................................6

Sinnamon, Gordon J.

382

Calendar Year study term 1  

E-print Network

or Physics Introductory Electromagnetism and Wave Motion Complementary studies elective Study Term 3 Engineering Aerospace Materials Study Term 6 Probability and Statistics Applied Thermodynamics Mechanical

Dawson, Jeff W.

383

Hybrid receiver study  

NASA Technical Reports Server (NTRS)

The results are presented of a 4 month study to design a hybrid analog/digital receiver for outer planet mission probe communication links. The scope of this study includes functional design of the receiver; comparisons between analog and digital processing; hardware tradeoffs for key components including frequency generators, A/D converters, and digital processors; development and simulation of the processing algorithms for acquisition, tracking, and demodulation; and detailed design of the receiver in order to determine its size, weight, power, reliability, and radiation hardness. In addition, an evaluation was made of the receiver's capabilities to perform accurate measurement of signal strength and frequency for radio science missions.

Stone, M. S.; Mcadam, P. L.; Saunders, O. W.

1977-01-01

384

Studying lightning strikes  

NASA Astrophysics Data System (ADS)

Scientists studying thunderstorms hope that using an “uninhabited aerial vehicle,” or UAV will allow them to overcome speed limitations of conventional aircraft to gain a better understanding of weather data and forecasting.Researchers with the Altus Cumulus Electrification Study (ACES) say that the Altus UAV flies at between 129 and 185 kilometers per hour, slower than conventional aircraft. This should allow the 55-foot wingspan vehicle to provide a longer-duration picture of thunderstorms without putting pilots and airborne researchers at risk during an August field campaign, based out of Naval Air Station Key West in Florida.

Showstack, Randy

385

STUDIES ON ENZYME ACTION  

PubMed Central

A number of different methods of treatment of unripe and ripe bananas for the purpose of obtaining and studying sucrolytic and amylolytic enzymes are described. No conclusive evidence of the presence of an amlyase could be obtained in any of the preparations. The sucrase of unripe and ripe bananas was studied more extensively. With ripe bananas, both soluble and insoluble sucrase preparations were obtained. Conditions for converting the soluble into an insoluble form were found. The actions of the sucrase preparations as far as the hydrogen ion concentration for maximum action and the time-action relation are concerned are similar to the behavior of the yeast and the potato sucrase. PMID:19871890

Falk, K. George; McGuire, Grace

1921-01-01

386

CTR plasma engineering studies  

NASA Astrophysics Data System (ADS)

Research in several areas is reported including: (1) transport in compact tori; (2) bremsstrahlung energy deposition in first wall materials, (3) Coulombic energy transfer collisions; (4) magnetic helicity injection study; (5) blankets for tritium catalyzed deuterium fusion reactors; (6) exploratory studies of applications of optimal control theory; (7) design of a burn dynamic experiment; (8) alpha driven low frequency fast magnetosonic wave microinstability in tandem mirror; (9) fusion product heating and confinement in a tandem mirror; and (10) velocity-space particle loss in field reversed configurations.

Miley, G. H.

387

Reporting of teratology studies.  

PubMed

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. PMID:23138913

Barrow, Paul C; Reynaud, Lucie

2013-01-01

388

Studies in neuroendocrine pharmacology  

NASA Technical Reports Server (NTRS)

The expertise and facilities available within the Medical Sciences Program section on Pharmacology were used along with informational input from various NASA sources to study areas relevant to the manned space effort. Topics discussed include effects of drugs on deprivation-induced fluid consumption, brain biogenic amines, biochemical responses to stressful stimuli, biochemical and behavioral pharmacology of amphetamines, biochemical and pharmacological studies of analogues to biologically active indole compounds, chemical pharmacology: drug metabolism and disposition, toxicology, and chemical methodology. Appendices include a bibliography, and papers submitted for publication or already published.

Maickel, R. P.

1976-01-01

389

Advanced engine study program  

NASA Technical Reports Server (NTRS)

A design and analysis study was conducted to provide advanced engine descriptions and parametric data for space transfer vehicles. The study was based on an advanced oxygen/hydrogen engine in the 7,500 to 50,000 lbf thrust range. Emphasis was placed on defining requirements for high-performance engines capable of achieving reliable and versatile operation in a space environment. Four variations on the expander cycle were compared, and the advantages and disadvantages of each were assessed. Parametric weight, envelope, and performance data were generated over a range of 7,500 to 50,000 lb thrust and a wide range of chamber pressure and nozzle expansion ratio.

Masters, A. I.; Galler, D. E.; Denman, T. F.; Shied, R. A.; Black, J. R.; Fierstein, A. R.; Clark, G. L.; Branstrom, B. R.

1993-01-01

390

Studies of American fusilinids  

E-print Network

UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTR 'BUTTONS PROTOZOA ARTICLE 1 Pages 1-184, Plates 1-38, Figures 1-7 STUDIES OF AMERICAN FUSULINIDS By M. L. THOMPSON UNIVERSITY OF KANSAS PUBLICATIONS October 15, 1948 PRINTED BY FERD VOILAND, JR . STATE...UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTR 'BUTTONS PROTOZOA ARTICLE 1 Pages 1-184, Plates 1-38, Figures 1-7 STUDIES OF AMERICAN FUSULINIDS By M. L. THOMPSON UNIVERSITY OF KANSAS PUBLICATIONS October 15, 1948 PRINTED BY FERD VOILAND, JR . STATE...

Thompson, M. L.

1948-10-15

391

Social Studies School Service  

NSDL National Science Digital Library

Beginning this month, socialstudies.com offers an Online Course for New History/ Social Studies Teachers designed to provide new teachers with icebreakers, lesson plans, background pedagogy, and activities for the classroom. Currently, IceBreakers, Introduction to Social Studies, and Lesson Planning (including over a dozen sample lessons) are online with Creative Lessons, Idea Books and Activities, and Assessment to follow. Lesson Planning also gives lists of supplementary print resources from socialstudies.com, which may be purchased online, and links to useful educational Websites.

392

Morphing Terminology Study  

SciTech Connect

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.

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

2010-06-28

393

Teaching Social Studies Methods  

NSDL National Science Digital Library

Teaching Social Studies to K-8 students is an engaging and creative process. Children learn best when they are interested and engaged in local and personal history. Connecting historical events to children\\'s lives is a powerful way to develop historical and cultural awareness. In this exercise you will be able to find some national and local resources to help you design and implement Social Studies in your K-8 classrooms. So let\\'s get started! First let\\'s see what kinds of resources are available on the web and other virtual places that are engaging and interesting ...

Kalvaitis, Darius

2006-02-17

394

School of Labour Studies Tom Szuty -Labour Studies Graduate  

E-print Network

case studies on employment and human rights Labour Studies 4F03 (Labour & the Environment) Learn aboutSchool of Labour Studies Tom Szuty - Labour Studies Graduate ­ Labour Relations Officer Cindy Gangaram - Labour Studies Graduate - Teaching #12;2 Andrea Horvath Labour Studies grad and first woman

Thompson, Michael

395

Go Abroad in Liberal StudiesLiberal Studies  

E-print Network

Go Abroad in Liberal StudiesLiberal Studies Program Web: http://oregonstate. edu/cla/liberal_studies.reception @oregonstate.edu Web: oregonstate.edu/ international The Liberal Studies degree is ideally suited for students who wish to study abroad! The Liberal Studies major allows students to design their own

Escher, Christine

396

ASIAN STUDIES Each summer the Pitt in India study  

E-print Network

ASIAN STUDIES CENTER Each summer the Pitt in India study abroad program introduces students to the fascinating country of India. The University of Pittsburgh's Study Asian Studies Center . 4400 Posvar Hall://www.ucis.pitt.edu/asc Study Abroad The South Asian Studies Center at the University of Pittsburgh (Pitt) is dedicated

Sibille, Etienne

397

STUDY ABROADFOR MARINE AND FRESHWATER BIOLOGY MAJORS study abroad  

E-print Network

STUDY ABROADFOR MARINE AND FRESHWATER BIOLOGY MAJORS study abroad #12;WHY YOU SHOULD STUDY ABROAD 2 STUDY ABROAD FOR MARINE AND FRESHWATER BIOLOGY MAJORS Study abroad programs provide Marine financial aid? STUDY ABROAD FOR MARINE AND FRESHWATER BIOLOGY MAJORS 3 · How will I get credit

John, Lizy Kurian

398

Writing in Social Studies.  

ERIC Educational Resources Information Center

Writing needs to be given adequate emphasis in the area of social studies. Teachers should attempt to be creative and to assign different kinds of writing in their classes. This paper discusses possible activities for students in a unit on the Middle East to illustrate diverse purposes in writing. An initial assignment could be to ask students to…

Ediger, Marlow

399

Native American Case Studies  

NSDL National Science Digital Library

The Native American Case Studies collection includes more than 80 original, research-based teaching cases focusing on contemporary issues in Indian Country. Teaching notes accompany each case. These can be downloaded and used at no cost. Additional website resources include information on teaching with cases and assessment. Guidelines for submitting cases are also available.

The Evergreen State College

400

Repository seals requirements study  

SciTech Connect

The Yucca Mountain Site Characterization Project, managed by the Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) is conducting investigations to support the Viability Assessment and the License Application for a high-level nuclear waste repository at Yucca Mountain, Nevada. The sealing subsystem is part of the Yucca Mountain Waste Isolation System. The Yucca Mountain Site Characterization Project is currently evaluating the role of the sealing subsystem (shaft, ramp and exploratory borehole seals) in achieving the overall performance objectives for the Waste Isolation System. This report documents the results of those evaluations. This report presents the results of a repository sealing requirements study. Sealing is defined as the permanent closure of the shafts, ramps, and exploratory boreholes. Sealing includes those components that would reduce potential inflows above the repository, or that would divert flow near the repository horizon to allow vertical infiltration to below the repository. Sealing of such features as emplacement drifts was not done in this study because the current capability to calculate fracture flow into the drifts is not sufficiently mature. The objective of the study is to provide water or air flow performance based requirements for shafts, ramps, and exploratory boreholes located near the repository. Recommendations, as appropriate, are provided for developing plans, seals component testing, and other studies relating to sealing.

NONE

1997-11-03

401

Racer efficacy study  

Technology Transfer Automated Retrieval System (TEKTRAN)

Racer (ammonium nonanoate) is a non-selective contact herbicide that controls several weed species. Racer has been labeled by EPA in the past year for weed control in food crops and is close to receiving approval for use by organic producers. The objective of this study was to verify results from ...

402

LUXEMBOURG INCOME STUDY (LIS)  

EPA Science Inventory

The LIS database is a collection of household income surveys. The LIS project began in 1983 under the joint sponsorship of the government of the Grand Duchy of Luxembourg and the Center for Population, Poverty and Policy Studies (CEPS). The project is mainly funded by the nationa...

403

Teaching Social Studies Indepth  

ERIC Educational Resources Information Center

Social studies, too frequently, is taught in a survey approach whereby pupils obtain subject matter in a shallow manner. Forgetting and hazy recalls are typical of this procedure of instruction. Covering many topics in a relatively short period of time does not make for achievement which is long-lasting. Then too, selected pupils might be left…

Ediger, Marlow

2014-01-01

404

Soil washing treatability study  

SciTech Connect

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.

Krstich, M.

1995-12-01

405

Ethics and Study Abroad  

ERIC Educational Resources Information Center

It came as a great surprise recently to read in "The New York Times" that the New York attorney general's office had launched an investigation into possible financial improprieties between colleges and outside organizations that provide study-abroad programs. Subpoenas had been issued to five of the largest program providers, "with more to come."…

Hoffa, William W.

2007-01-01

406

1992 NACUBO Endowment Study.  

ERIC Educational Resources Information Center

This report presents the results of a 1992 study of the performance and management of college and university endowments. Part I offers succinct information on the data collection process, provides definitions, and explains the formula used in the analysis. Part II presents the report's exhibits in two sections. The first section describes: (1)…

National Association of College and University Business Officers, Washington, DC.

407

1991 NACUBO Endowment Study.  

ERIC Educational Resources Information Center

This report presents the results of a 1991 study of the performance and management of endowments of colleges and universities. Part I offers information on the data collection and describes several definitions and formula used in the analysis. Part II presents the report's exhibits in two sections the first of which treats endowment…

National Association of College and University Business Officers, Washington, DC.

408

Toxicological study of NTO  

Microsoft Academic Search

The acute oral LDââ values for NTO for mice and rats are greater than 5 g\\/kg. According to classical guidelines, the test material would be considered only slightly toxic or practically non-toxic in both species. Skin application studies in the rabbit with NTO demonstrated that it was mildly irritating cutaneously. With the scoring scheme, the rabbit eye test was considered

J. E. London; D. M. Smith

1985-01-01

409

Studies in Empowerment.  

ERIC Educational Resources Information Center

This theme issue of the serial "Educational Foundations" contains five articles devoted to the topic of "Studies in Empowerment." In "The Disempowering of Empowerment: Out of the Revolution and into the Classroom," Margaret D. LeCompte and Kathleen Bennett deMarrais focused on placing the term in proper historical context. Guy B. Senese "Away from…

Van Galen, Jane, Ed.; And Others

1992-01-01

410

Proof Study: Gender Differences  

E-print Network

Proof Study: Gender Differences 11/29/01 Kyle Green Dan Beaver Marquis Bennett Eric Germo Rick survey focusing on the gender differences in the answers. First, both of the male and the female grade's easy," then you most likely have had some mathematical background. But how much of a background in math

Nguyen, Hieu D.

411

GRADUATE STUDY IN LINGUISTICS  

E-print Network

on a larger time scale. Both genetic and typological dimensions of change are of interest, with faculty specialities in Australian Aboriginal, Uto-Aztecan, Indo-European and Austronesian languages. The study, students gain both an appreciation of the linguistic diversity found in the world and an understanding

412

Access to space study  

NASA Technical Reports Server (NTRS)

This report summarizes the results of a comprehensive NASA in-house study to identify and assess alternate approaches to access to space through the year 2030, and to select and recommend a preferred cause of action. The goals of the study were to identify the best vehicles and transportation architectures to make major reductions in the cost of space transportation (at least 50%), while at the same time increasing safety for flight crews by at least an order of magnitude. In addition, vehicle reliability was to exceed 0.98 percent, and, as important, the robustness, pad time, turnaround time, and other aspects of operability were to be vastly improved. This study examined three major optional architectures: (1) retain and upgrade the Space Shuttle and expendable launch vehicles; (2) develop new expendable vehicles using conventional technologies and transition from current vehicles beginning in 2005; and (3) develop new reusable vehicles using advanced technology, and transition from current vehicles beginning in 2008. The launch-needs, mission model utilized for for the study was based upon today's projection of civil, defense, and commercial mission payload requirements.

1994-01-01

413

Biosynthetic studies on taxol  

Microsoft Academic Search

The biosynthesis of the plant antitumor agent, taxol, was studied by feeding radioactive or stable isotope-labeled precursors to cut stems or to inner bark tissue of Taxus brevifolia. The labeled taxol was purified to radiochemical purity and subjected to chemical degradation or was analyzed by electrospray tandem mass spectrometry. It was demonstrated that in the plant taxol is synthesized from

P. E. Fleming; G. Floss; M. Haertel; A. R. Knaggs; A. Lansing; U. Mocek; K. D. Walker

1994-01-01

414

Urban Expansion Study  

NASA Technical Reports Server (NTRS)

Under an Egyptian government contract, PADCO studies urban growth in the Nile Area. They were assisted by LANDSAT survey maps and measurements provided by TAC. TAC had classified the raw LANDSAT data and processed it into various categories to detail urban expansion. PADCO crews spot checked the results, and correlations were established.

1985-01-01

415

Nurses' Health Study (1976-)  

Cancer.gov

Additional Information The Nurses' Health Study was launched in 1976, when 121,700 registered nurses, aged 30-55 years, responded to a mailed questionnaire regarding their health and lifestyle. Women continue to be followed via questionnaires every 2 years. Incident cases of cancer and selected other diagnoses are documented by reviewing medical records.

416

Digital communications study  

NASA Technical Reports Server (NTRS)

Research is reported dealing with problems of digital data transmission and computer communications networks. The results of four individual studies are presented which include: (1) signal processing with finite state machines, (2) signal parameter estimation from discrete-time observations, (3) digital filtering for radar signal processing applications, and (4) multiple server queues where all servers are not identical.

Boorstyn, R. R.

1973-01-01

417

General Aviation Manpower Study.  

ERIC Educational Resources Information Center

Highlights a study examining manpower supply/demand in general aviation. Eight job categories were examined: pilots, flight instructors, engineers, machinists/toolers, and A&P, airframe, and avionics technicians. Findings among others indicate that shortages in indicated job categories exist because personnel are recruited by other industries. (JN)

Feller, Richard

1982-01-01

418

Financial Distress Study Report.  

ERIC Educational Resources Information Center

This report, undertaken by the Secretary of the Department of Health, Education, and Welfare, Elliott Richardson, seeks to establish the need for emergency financial assistance to medical and dental schools, and includes recommendations for appropriate administrative and legislative action. The directive to undertake the study was a provision of…

National Institutes of Health (DHEW), Bethesda, MD. Bureau of Health Manpower Education.

419

NGLW RCRA Storage Study  

SciTech Connect

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.

R. J. Waters; R. Ochoa; K. D. Fritz; D. W. Craig

2000-06-01

420

Actuarial and Financial Studies  

E-print Network

DN200 Science DN230 Actuarial and Financial Studies DN201 Computer Science SCIENCE 2014 UCD Your Physiology 13 DN200 Zoology 15 DN200 Plant Biology 14 DN200 Chemistry 19 DN200 Chemistry with Biophysical Chemistry 20 DN200 Chemistry with Environmental & Sustainable Chemistry 21 DN200 DN200 Chemistry & Chemical

421

Social Studies; Colonial America.  

ERIC Educational Resources Information Center

Students in grades seven through nine will examine and analyze the political organization, social structure, economic life, and values of the American Colonial period in this quinmester arranged American Studies course. Since the thirteen English Colonies effected the United States development, many of our nations foundations in government,…

Hanson, Paul S.

422

Incinerated waste consolidation studies  

SciTech Connect

Products from rotary-kiln incineration studies previously conducted at Colorado School of Mines Research Institute on simulated transuranic waste materials were separated into size fractions. Each size fraction was then consolidated by cementing into drums. The purposes of the study were to determine the effectiveness of various types of equipment in separating the fine <1/4-in. ash from >1/4-in. incinerated waste and to study and evaluate various procedures involved in the use of portland cement concrete in consolidating incinerated simulated transuranic waste materials after size separation. Results of the study showed that either a trommel drum or a vibrating screen device produced the highest separation efficiency and met the operating requirements of no hang-up of material, minimal screen plugging, low number of moving parts, and a small space requirement. Sawing the cured drums of consolidated material showed that mixing <1/4-in. ash into the portland cement grout before pouring and vibrating the grout into the >1/4-in. material produced a sound, solid product with no voids. No significant temperature rise was recorded inside the consolidated drums during the 7 days of monitoring.

Pattengill, M.G.; Bentzen, E.H. III; Roushey, W.J.; Rau, E.L.

1983-06-01

423

Early Childhood Social Studies.  

ERIC Educational Resources Information Center

Noting ongoing difficulties in identifying the fundamental role of social studies in educating young children, this chapter focuses on how children begin to develop historical and geographic understanding. The chapter considers age-appropriate and developmental concerns and the role of national standards in history and geography. The chapter…

Jantz, Richard K.; Seefeldt, Carol

424

Esophagram (Barium Swallow Study)  

MedlinePLUS

... up. You will be given a gown to wear. The esophagram barium swallow uses x-rays and anyone who is pregnant cannot be in the room during the x-ray. During the Test Before the study you/your child will need ...

425

AGRICULTURAL HEALTH STUDY  

EPA Science Inventory

The Agricultural Health Study is a large cohort of 90,000 licensed pesticide applicators, plus 30,000 spouses and 20,000 children who are exposed either directly or indirectly. Exposure to pesticides is widespread and is important beyond the agricultural community. Other exposure...

426

Resources for Interdisciplinary Studies  

ERIC Educational Resources Information Center

Resources for interdisciplinary studies (IDS) appear in a multitude of print publications, online forums, and the "fugitive" or "gray" literature of conference papers, reports, and curriculum materials. The quantity is not surprising, since interdisciplinary discussions have expanded as new fields and approaches emerged across all domains of…

Klein, Julie Thompson

2006-01-01

427

HOUSTON AEROSOL CHARACTERIZATION STUDY  

EPA Science Inventory

An intensive field study of ambient aerosols was conducted in Houston between September 14 and October 14, 1978. Measurements at 12 sites were made using (1) two relocatable monitoring systems instrumented for aerosol and gaseous pollutants, (2) a network of high volume samplers ...

428

Summer Study Columbia College  

E-print Network

Summer Study Columbia College How many points may I take through Columbia's Summer Session? Columbia students may take no more than eight points in any Columbia Summer Session period or in overlapping periods, and a maximum of sixteen points for the entire summer. May I take any class during

Hone, James

429

PHILADELPHIA ROADWAY STUDY  

EPA Science Inventory

The Philadelphia Roadway Study was conducted to determine the horizontal and vertical extinction profiles of particles generated by vehicles, including fine (0-2.5 micrometers), coarse (2.5-15 micrometers), and total (0-15 micrometers) size fractions in the area surrounding a maj...

430

International Study Center Raitenhaslach  

E-print Network

Gottfried Wilhelm Leibniz-Preis 2012 (s. Seite 14). Die von der DFG verlie- hene Auszeichnung würdigt diePolitik: International Study Center Raitenhaslach Forschen: Leibniz-Preis für Barbara Wohlmuth: Leibniz-Preis für Barbara Wohlmuth campusDas Magazin der TU München 1| 2012 Impressum TUMcampus Das

431

Polymer infiltration studies  

NASA Technical Reports Server (NTRS)

The preparation is reported of carbon fiber composites using advanced polymer resins. Current and ongoing research activities include: powder towpreg process; weaving, braiding and stitching dry powder prepreg; advanced tow placement; and customized ATP towpreg. The goal of these studies is to produce advanced composite materials for automated part fabrication using textile and robotics technology in the manufacture of subsonic and supersonic aircraft.

Marchello, Joseph M.

1992-01-01

432

Supplemental Language Study Program.  

ERIC Educational Resources Information Center

The Supplemental Language Study Group (SLSG) program at Colorado State University (Fort Collins, Colorado) is described. The program was developed following a student's expression of interest in learning "exotic" languages unavailable in the standard foreign language curriculum at the university. This student-run club offers several weekly…

Colorado State Univ., Ft. Collins.

433

Tethered gravity laboratories study  

NASA Technical Reports Server (NTRS)

The use is studied of tether systems to improve the lowest possible steady gravity level on the Space Station. Particular emphasis is placed by the microgravity community on the achievement of high quality microgravity conditions. The tether capability is explored for active control of the center of gravity and the analysis of possible tethered configurations.

Lucchetti, F.

1989-01-01

434

INTRODUCTION AND STUDY DESIGN  

EPA Science Inventory

Under the sponsorship of the UNEP/ILO/IPCS, 17 laboratories from diverse regions of the world participated in evaluating the utility of four plant bioassays for detecting genetic hazards of environmental chemicals. he bioassays included in this collaborative study were Arabidopsi...

435

The Black Studies Debate.  

ERIC Educational Resources Information Center

Beginning with the selection of Professor Newby, who attempts to reveal the role which historians, perhaps more specifically white historians, have played and continue to play in the perpetuation of racism in American culture, this anthology concludes with an analysis of the present status of Black Studies. W. Arthur Lewis' critical essay attempts…

Gordon, Jacob U., Ed.; Rosser, James M., Ed.

436

Studies of perfume solubilisation.  

PubMed

Synopsis The solubilisation of three perfumes has been studied in monoethanolamine lauryl sulphate and sodium lauryl ether sulphate solutions. The effect of the addition of nonionic surfactants have also been followed. A method is described for the olfactive examination of the solutions and results are given for its application to certain of the systems. PMID:19467036

Blakeway, J M; Bourdon, P; Seu, M

1979-02-01

437

Comparative Ethnic Studies  

E-print Network

Any UCORE, most commonly: MATH 105: Exploring Mathematics PHIL 201: Elementary Logic Core Courses CES education provides unique opportunities for students to work closely with faculty on independent studies is a resource for majors who are pursuing graduate degrees, undergraduate research, academic publications

Collins, Gary S.

438

Social Studies: Grade 8.  

ERIC Educational Resources Information Center

This Manitoba (Canada) curriculum guide for eighth grade social studies students contains suggested teaching strategies and learning activities in four units covering: (1) life during prehistoric and early historic times; (2) ancient civilizations; (3) life in early modern Europe; and (4) life in the modern world. Each unit includes an overview,…

Manitoba Dept. of Education, Winnipeg.

439

Geosynchronous Technology Infusion Studies  

NASA Technical Reports Server (NTRS)

NASA and NOAA are now sponsoring Advanced Geosynchronous Studies (AGeoS), technology work that will lead to the next generation of space sensors located in geosynchronous orbit. This report briefly describes the initial steps being taken to investigate the high priority geosynchronous measurement needs identified so far.

Hilliard, L.; Jenstrom, D.; Chesters, D.; Racette, P.

1997-01-01

440

Environmental Studies An Overview  

E-print Network

Environmental Studies An Overview Environmental scientists conduct research to identify and abate the environment--degradation, conservation, recycling, and replenishment--is central to the work of environmental water supplies, and reclaim contaminated land and water to comply with federal environmental regulations

Colorado at Boulder, University of

441

Graduate studies Ecosystem Science  

E-print Network

Graduate studies in Ecosystem Science and Management Ph.D. M.S. M.Agr. or Natural Resources Development MNRD Department of Ecosystem Science and Management College of Agriculture and Life Sciences. The thesisbased Master of Science and Ph.D. degrees are designed for research or academic careers

442

Study of Nursing Mothers  

ERIC Educational Resources Information Center

The participation of women in a higher education program depends on the extent to which the program takes into consideration the special needs of women--issues that have long plagued women's participation in education programs. In this study, we found that issues like childcare have not received any special consideration in the delivery of…

Kazeem, Kolawole

2006-01-01

443

American Studies Module Information  

E-print Network

: American Security Policy in the Post-Cold War Era PO-237 The Politics of Latin America on Film HUA-206 culture including film, art, photography and pop culture. This approach seeks to situate AmericanBA American Studies Module Information 2014-2015 www.swansea.ac.uk/artsandhumanities Department

Harman, Neal.A.

444

Master Study: Ceramics  

ERIC Educational Resources Information Center

In painting and drawing classes, it is typical to ask students to work directly from a master. It is one way to study composition techniques, and to become familiar with classical style firsthand. In museums, easels are set up as artists work, not in an attempt to copy or plagiarize, but in an attempt to be part of history by participating in it.…

Clark, Kelly

2004-01-01

445

Teleoperator human factors study  

NASA Technical Reports Server (NTRS)

The progress made on the Teleoperator Human Factors Study program during the period of September 7, 1985 to October 6, 1985 is discussed. Technical and programmatic problems that were encountered are discussed along with activity planned for the following month. The main portion of the report has been separated into four sections: Work Performed, Future Work, Problems Encountered, and Cost Information.

Bradford, K. Z.; Schappell, R. T.

1985-01-01

446

Graduate Studies September 2011  

E-print Network

Graduate Studies September 2011 1 Fall Term begins 5 Labour Day 12 Fall Term classes begin 30 Last Term without SGS approval 10 Thanksgiving Day 16 University Day November 2011 11 Remembrance Day (classes cancelled 10:30 - 11:30 am) 15 - 16 Fall Convocation December 2011 2 Fall Term classes end 3 - 6

Graham, Nick

447

Courses of Study Accreditation  

E-print Network

be found at dpb.cornell.edu/accreditation.htm. Requests to review additional documentation supporting and Planning, Cornell University, 441 Day Hall, Ithaca, NY 14853-2801, mec30@cornell.edu. Cornell UniversityCourses of Study 2009­2010 Accreditation Cornell University is accredited by the Middle States

Chen, Tsuhan

448

Courses of Study Accreditation  

E-print Network

be found at dpb.cornell.edu/accreditation.htm. Requests to review additional documentation supporting and Planning, Cornell University, 441 Day Hall, Ithaca, NY 14853-2801, mec30@cornell.edu. Cornell UniversityCourses of Study 2010­2011 Accreditation Cornell University is accredited by the Middle States

Chen, Tsuhan

449

Courses of Study Accreditation  

E-print Network

be found at dpb.cornell.edu/accreditation.htm. Requests to review additional documentation supporting and budget, Cornell University, 441 Day Hall, Ithaca, NY 14853-2801, ps33@cornell.edu. Cornell UniversityCourses of Study 2008­2009 Accreditation Cornell University is accredited by the Middle States

Chen, Tsuhan

450

Maximum Tolerated Dose Studies  

Microsoft Academic Search

A three-stage maximum repeatable dose (MRD) protocol is described in which the MRD is established by dose incrementation, followed by administration of this dose for at least seven days, with the final stage being single dose administration of the doses anticipated for the one-month studies. The toxicokinetic measurements which are made in support of this protocol are illustrated with data

P. F. Carey; N. W. Spurling

1994-01-01

451

Teaching Biblical Studies Online  

ERIC Educational Resources Information Center

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…

Delamarter, Stephen; Gravett, Sandra L.; Ulrich, Daniel W.; Nysse, Richard W.; Polaski, Sandra Hack

2011-01-01

452

Silicon sheet surface studies  

NASA Technical Reports Server (NTRS)

Several activities were performed in the area of silicon sheet surface studies. An interferometry technique was developed for measuring residual stresses in short, thin silicon sheets. Simulation of abrasion of silicon by diamond and by scrating and indentation tests was carried out. The wear rate in silicon was correlated with a wear model.

Danyluk, S.

1984-01-01

453

MONTEFIORE - ASTHMA INTERVENTION STUDY  

EPA Science Inventory

Montefiore Medical Center is conducting an asthma intervention study using, in part, their Lead Safe House on the Montefiore campus, a low-allergen controlled setting. There are three groups of participants, all severe asthmatics. The first group is being moved temporarily into...

454

HANOVER PARK TERTIARY STUDIES  

EPA Science Inventory

During a one year study, four tertiary treatment units were tested and evaluated. Three of the units were deep-bed filters which were used to treat secondary plant effluent. The types of filters used were: (1) an upflow filter with a sand media, (2) a downflow gravity filter with...

455

Turbine blade damping study  

NASA Technical Reports Server (NTRS)

Research results and progress on the performance of bladed systems is reported the different topics discussed include: the study of turbine blade damping; forced vibrations of friction damped beam moistures in two dimensions; and a users manual for a computer program for dynamic analysis of bladed systems.

Dominic, R. J.

1984-01-01

456

Faculty Retention Study, 2002.  

ERIC Educational Resources Information Center

This survey attempted to study factors important to making faculty decide to continue or terminate employment at South Texas Community College (STCC). Surveys were e-mailed to 276 full time, regular faculty and 170 adjunct faculty with valid STCC e-mail addresses. Although 54% (150) of the full time faculty responded to the survey, it remains a…

South Texas Community Coll., McAllen. Office of Institutional Research and Effectiveness.

457

Social Studies Journal, 2003.  

ERIC Educational Resources Information Center

This theme issue of the "Social Studies Journal" focuses on the worldwide conflict known in the United States as the French and Indian War (1754-1763). The volume is dedicated to examining the conflict in Pennsylvania. Western Pennsylvania became a battle-scarred landscape as the British and French, with their Native American allies, struggled for…

West, Leo R., Ed.

2003-01-01

458

Parts application handbook study  

NASA Technical Reports Server (NTRS)

The requirements for a NASA application handbook for standard electronic parts are determined and defined. This study concentrated on identifying in detail the type of information that designers and parts engineers need and expect in a parts application handbook for the effective application of standard parts on NASA projects.

1978-01-01

459

SERT C project study  

NASA Technical Reports Server (NTRS)

The SERT C (Space Electric Rocket Test - C) project study defines a spacecraft mission that would demonstrate the technology readiness of ion thruster systems for primary propulsion and station keeping applications. As a low cost precursor, SERT C develops the components and systems required for subsequent Solar Electric Propulsion (SEP) applications. The SERT C mission requirements and preliminary spacecraft and subsystem design are described.

1974-01-01

460

Fundamental studies in geodynamics  

NASA Technical Reports Server (NTRS)

Progress in modeling instantaneous plate kinematics is reviewed, with emphasis on recently developed models of present day plate motions derived by the systematic inversion of globally distributed data sets. Rivera plate motions, the Caribbean South American boundary, Indian plate deformation, Pacific-North America, seismicity and subduction processes, and the study of slow earthquakes and free oscillations are discussed.

Anderson, D. L.

1980-01-01

461

Pangnirtung: A Community Study.  

ERIC Educational Resources Information Center

This booklet provides reference materials for teachers of social studies in the Northwest Territories (Canada). The information was gathered during workshops attended by elders, community representatives, and teachers from the region. A geography section describes the location of Pangnirtung on Baffin Island and the geology, climate, vegetation,…

Benyk, Pearl, Ed.

462

Healthcare Management & Insurance Studies  

E-print Network

Healthcare Management & Insurance Studies MINOR IN The Health Care field is a growth industry 06269 Required · Introduction to Healthcare Management · Health Care Industry Analysis Choose three courses from the below: · Health and Social Insurance · Healthcare Financial and Human Resource Management

Alpay, S. Pamir

463

Marine electromagnetic induction studies  

Microsoft Academic Search

In reviewing seafloor induction studies conducted over the last seven years, we observe a decline in single-station magnetotelluric (MT) experiments in favour of large, multinational, array experiments with a strong oceanographic component. However, better instrumentation, processing techniques and interpretational tools are improving the quality of MT experiments in spite of the physical limitations of the band limited seafloor environment, and

S. C. Constable

1990-01-01

464

Recycling Study Guide.  

ERIC Educational Resources Information Center

This study guide was designed to help teachers and students understand the problems surrounding solid wastes. It includes an overview of solid waste and recycling, a glossary, suggested activities and a list of resource publications, audiovisual materials and organizations. There are 19 activity suggestions included in this guide designed for use…

Hallowell, Anne; And Others

465

Social Studies: Local History.  

ERIC Educational Resources Information Center

Elementary and secondary school teachers interested in developing a local history unit can adapt this fourth grade program created for three school districts in Cortland County, New York. Material is divided into 13 chapters. Chapter 1 charts the New York fourth grade curriculum by concept and content and outlines specific community study…

Kressler, Joe, Comp.

466

International Studies Degree  

E-print Network

BGSU® n n n What I did with my International Studies Degree Bowing Green State University 103 Corporation Self-employed/Business Owner Indy Associates, Original Impulse Senior Associate International Force Research Laboratory Director, International Trade Office State of Colorado ­ Office of Economic

Moore, Paul A.

467

general studies degree yourgoalsyourpathwayyoursuccess  

E-print Network

Gordon, Manager-Credit Programs gordonse@ius.edu Richmond Indiana University East 2325 Chester Blvd.348.7257 www.iupuc.edu/generalstudies Vickie Welsh-Huston, General Studies Director vwelshhu@iupuc.edu Fort Wayne Indiana University­Purdue University Fort Wayne Kettler Hall 144 · 2101 E. Coliseum Blvd. Fort

Polly, David

468

Translation Studies with  

E-print Network

MSc in Translation Studies with TESOL School of Arts and Humanities A fantastic gateway to a career in translation and TESOL http://stir.ac.uk/im #12;Employment and research opportunities Whether you want to work is key. A career in translation could see you specialise in a whole range of diverse fields in public

Little, Tony

469

Indian Studies Guidelines.  

ERIC Educational Resources Information Center

In 1973 the Montana Legislature enacted the Indian Studies Law which required that by July 1, 1979 all certified personnel in schools on or in the vicinity of Montana's Indian reservations must have received training in the history, traditions, customs, values, beliefs, ethics, and contemporary affairs of American Indians, particularly the Montana…

Montana State Office of the Superintendent of Public Instruction, Helena.

470

Arc electrode interaction study  

NASA Technical Reports Server (NTRS)

The project consisted of two parts: (1) the cathode interaction studies which were a continuation of previous work and had the objective of increasing our understanding of the microscopic phenomena controlling cathode erosion in arc jet thrusters, and (2) the studies of the anode attachment in arc jet thrusters. The cathode interaction studies consisted of (1) a continuation of some modeling work in which the previously derived model for the cathode heating was applied to some specific gases and electrode materials, and (2) experimental work in which various diagnostics was applied to the cathode. The specific diagnostics used were observation of the cathode tip during arcing using a Laser Strobe Video system in conjunction with a tele-microscope, a monochromator with an optical multichannel analyzer for the determination of the cathode temperature distribution, and various ex situ materials analysis methods. The emphasis of our effort was shifted to the cathode materials analysis because a parallel project was in place during the second half of 1993 with a visiting scientist pursuing arc electrode materials studies. As a consequence, the diagnostic investigations of the arc in front of the cathode had to be postponed to the first half of 1994, and we are presently preparing these measurements. The results of last year's study showed some unexpected effects influencing the cathode erosion behavior, such as increased erosion away from the cathode tip, and our understanding of these effects should improve our ability to control cathode erosion. The arc jet anode attachment studies concentrated on diagnostics of the instabilities in subsonic anode attachment arc jet thrusters, and were supplemental measurements to work which was performed by one of the authors who spent the summer as an intern at NASA Lewis Research Center. A summary of the results obtained during the internship are included because they formed an integral part of the study. Two tasks for 1994, the diagnostics of the anode closure phenomenon, and the use of arc jet thrusters for the deposition of c-BN, are being prepared.

Zhou, X.; Berns, D.; Heberlein, J.

1994-01-01

471

Tire footprint studies  

NASA Technical Reports Server (NTRS)

This presentation covers the results of tire footprint studies conducted in the Landing Gear Development Facility of the USAF Wright Laboratory at the Wright Patterson Air force Base, OH. Tire footprint studies are essential in understanding tire wear mechanisms and computing tire tread wear rates. The power input into the tread is the driving force for tread wear. Variables needed for power input calculations include the footprint pressure and slip velocity distributions. Studies were performed on the effects of power input distributions due to vertical load, camber, yaw, inflation pressure, and tire construction. For the present study, two tire constructions, one radial and the other bias, were selected. These tires were for the F-16 Block 30 fighter aircraft, both of which were previously worn. The present study was limited to steady straight roll with a 14,000 lb vertical load, a 310 psi inflation pressure, and zero yaw and camber. All tests were conducted on the Tire Force Machine (TFM) with a specialized sensor plate with embedded pressure sensors (X, Y, and Z) and slip sensors (X and Y). All tests were conducted for a table speed of 1 in/s. Tests on the TFM show that the power intensity distributions and total power for both tire constructions are quite similar for straight roll. Later on, tests were also conducted on a modified dynamometer which was overlaid with a grit wear surface. The tire speed was maintained at 40 miles per hour and yaw was set to four degrees. Dynamometer tests showed that radial tires have more tread wear than the bias tire; however, in the field, radial tires have longer life.

Chawla, Mangal; Medzorian, John

1995-01-01

472

Photovoltaic evaluation study  

NASA Astrophysics Data System (ADS)

Realizing the value and potential of PV-power as well as the growing need for increased cooperation and sharing of knowledge in the field of photovoltaics, FINNIDA and UNICEF decided to undertake a study of selected PV-projects. There were two main objectives for the study: To gather, compile, evaluate and share information on the photovoltaic technology appropriate to developing countries, and to promote the interest and competence of Finnish research institutes, consultants and manufacturers in photovoltaic development. For this purpose a joint evaluation of significant, primarily UN-supported projects providing for the basic needs of rural communities was undertaken. The Gambia and Kenya offered a variety of such projects, and were chosen as target countries for the study. The projects were chosen to be both comparable and complimentary. In the Gambia, the main subject was a partially integrated health and telecommunications project, but a long-operating drinking water pumping system was also studied. In Kenya, a health project in the Turkana area was examined, and also a large scale water pumping installation for fish farming. Field visits were made in order to verify and supplement the data gathered through document research and earlier investigations. Individual data gathering sheets for the project form the core of this study and are intended to give the necessary information in an organized and accessible format. The findings could practically be condensed into one sentence: PV-systems work very well, if properly designed and installed, but the resources and requirements of the recipients must be considered to a higher degree.

Johnson, G.; Heikkilae, M.; Melasuo, T.; Spanner, S.

473

Public Works Transportation Infrastructure Study  

E-print Network

Public Works Transportation Infrastructure Study Minneapolis City of Lakes Minneapolis Public Works Transportation Infrastructure Study #12;Public Works Transportation Infrastructure Study Minneapolis City Works Transportation Infrastructure Study Minneapolis City of Lakes Background: · Currently, funding

Minnesota, University of

474

ENVIRONMENTAL STUDIES BOARD AIRPORTA MULTIDISCIPLINARY  

E-print Network

ENVIRONMENTAL STUDIES BOARD JAMAICA BAYAND KENNEDY AIRPORTA MULTIDISCIPLINARY ENVIRONMENTAL STUDY Volume II A REPORT OF THE JAMAICA BAY ENVIRONMENTAL STUDY GROUP NATIONAL ACADEMY OF SCIENCES NATIONAL II of the report, Jamaica Bay and Kennedy Airport: A Multidisciplinary Environmental Study, prepared

475

Repository seals requirement study  

SciTech Connect

The Yucca Mountain Site Characterization Project, managed by the Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) is conducting investigations to support the Viability Assessment and the License Application for a high-level nuclear waste repository at Yucca Mountain, Nevada. The sealing subsystem is part of the Yucca Mountain Waste Isolation System. The Yucca Mountain Site Characterization Project is currently evaluating the role of the sealing subsystem (shaft, ramp and exploratory borehole seals) in achieving the overall performance objectives for the Waste Isolation System. This report documents the results of those evaluations. The objective of the study is to provide water or air flow performance based requirements for shafts, ramps, and exploratory boreholes located near the repository. Recommendations, as appropriate, are provided for developing plans, seals component testing, and other studies relating to sealing.

NONE

1997-11-03

476

Remote connector development study  

SciTech Connect

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.

Parazin, R.J.

1995-05-01

477

Laser evaporation studies  

NASA Astrophysics Data System (ADS)

The physics of vaporization of matter under pulsed CO2 laser evaporation was studied. Analysis of the nature of the vapor plume in several materials indicated the presence of numerous excited species, neutral as well as ionized species, and ions with high kinetic energies. High quality films of refractory metal oxides and epitaxial films of Ge were deposited. The oxide materials were dense and crystalline and had high refractive index values, even when deposited on room temperature substrates. Ge films were epitaxial and single crystalline when deposited on Si substrates at 300 C. Study of the relationship of deposition conditions and film properties clearly indicated the beneficial role of the energetic ions in the film deposition. Special emphasis was given to the solution of the problem of particulates in the films.

Sankur, H. O.

1987-10-01

478

Rotating Gravity Gradiometer Study  

NASA Technical Reports Server (NTRS)

The application of a Rotating Gravity Gradiometer (RGG) system on board a Lunar Polar Orbiter (LPO) for the measurement of the Lunar gravity field was investigated. A data collection simulation study shows that a gradiometer will give significantly better gravity data than a doppler tracking system for the altitudes under consideration for the LOP, that the present demonstrated sensitivity of the RGG is adequate for measurement of the Lunar gravity gradient field, and that a single RGG instrument will provide almost as much data for geophysical interpretation as an orthogonal three axis RGG system. An engineering study of the RGG sensor/LPO spacecraft interface characteristics shows that the RGG systems under consideration are compatible with the present models of the LPO spacecraft.

Forward, R. L.

1976-01-01

479

Laser evaporation studies  

NASA Astrophysics Data System (ADS)

The use of a pulsed laser to evaporate dielectric materials for optical thin film deposition was investigated. The electrical properties of the laser induced plasma in the evaporant plume were studied. High flux (20A/sq cm) of high velocity (1 to 10 million) cm/s) ionic species were observed in the TEA-CO2 laser evaporation of many refractory oxides, chalcogenides and fluorides. Thin films of ZrO2 were deposited out of a plasma described above. These films were dense, oriented polycrystalline and had bulk refractive index values (2,15), low absorption (K about 0.001) and low particulate density for a range of laser fluence values. In the next and final phase of this project, thin film studies will be extended to a wider array of materials, with emphasis on obtaining high quality films with low particulate densities.

Sankur, H.

1986-10-01

480

E85 Dispenser Study  

SciTech Connect

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.

Moriarty, K.; Johnson, C.; Sears, T.; Bergeron, P.

2009-12-01

481

ATF-1 torsatron studies  

SciTech Connect

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 <..beta..> 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.

Lyon, J.F.; Carreras, B.A.; Charlton, L.A.; Cooper, W.A.; Dory, R.A.; Fowler, R.H.; Garcia, L.; Harris, J.H.; Hender, T.C.; Hicks, H.R.

1983-01-01

482

Studies in oral leukoplakias  

PubMed Central

Oral carcinoma has been shown to be correlated with the use of tobacco in various parts of India. In a large-scale dental survey conducted in Lucknow, Bombay and Bangalore various precancerous conditions were investigated and studied for their possible relation to smoking and chewing habits. This paper reports the prevalence of oral leukoplakia among 10 000 dental-clinic patients in Lucknow and the correlation of the condition with the use of tobacco and betel nut in the study population. The results show that leukoplakia is far more prevalent among users of tobacco, betel nut or both than among non-users. A strikingly high frequency was found among smokers of the local cigarette, the bidi. PMID:5300044

Pindborg, J. J.; Kiær, Joyce; Gupta, P. C.; Chawla, T. N.

1967-01-01

483

1983 Mediterranean Studies  

NASA Astrophysics Data System (ADS)

After a lay-up of over 1 year and an extensive refit, R/V Robert D. Conrad of Lamont-Doherty Geological Observatory has left Port Everglades, Florida, bound for the Pacific Ocean off of South America. Most of the 1982 Conrad operations will be based in the Pacific, highlighted by a deep-water multichannel seismic reflection study of the Pacific Plate around Hawaii, to be conducted together with R/V Kana Keoki of the University of Hawaii. The scientific equipment on the Conrad is strongly oriented toward marine geophysical studies; however, she is also capable of carrying out limited biological, physical, and chemical oceanographic programs.Although plans are still preliminary, the 1983 Conrad schedule includes 2 months of operations in the Mediterranean Sea during the late spring or summer. This will be the first time since 1979 that a research vessel of the U.S. Academic Fleet has conducted scientific programs in the Mediterranean Sea.

484

EUROv Super Beam Studies  

SciTech Connect

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.

Dracos, Marcos [IPHC, Universite de Strasbourg, CNRS/IN2P3, F-67037 Strasbourg (France)

2011-10-06

485

Fundamental Pyrolysis Studies  

SciTech Connect

Progress on the direct mass spectrometric sampling of pyrolysis products from wood and its constituents is described for the period from June 1982 to February 1983. A brief summary and references to detailed reports, of the qualitative demonstration of our approach to the study of the separated processes of primary and secondary pyrolysis is presented. Improvements and additions to the pyrolysis and data acquisition systems are discussed and typical results shown. Chief of these are a heated-grid pyrolysis system for controlled primary pyrolysis and a sheathed flame arrangement for secondary cracking studies. Qualitative results of the secondary cracking of cellulose, lignin, and wood are shown as are comparisons with the literature for the pyrolysis spectra of cellulose, lignin, and levoglucosan. 'Fingerprints' for a number of materials are shown, with spectra taken under carefully controlled conditions so that sensitivity calibrations for different compounds, now being determined, can be applied.

Milne, T. A.; Evans, R. J.; Soltys, M. N.

1983-03-01

486

EOS mapping accuracy study  

NASA Technical Reports Server (NTRS)

Studies were performed to evaluate various image positioning methods for possible use in the earth observatory satellite (EOS) program and other earth resource imaging satellite programs. The primary goal is the generation of geometrically corrected and registered images, positioned with respect to the earth's surface. The EOS sensors which were considered were the thematic mapper, the return beam vidicon camera, and the high resolution pointable imager. The image positioning methods evaluated consisted of various combinations of satellite data and ground control points. It was concluded that EOS attitude control system design must be considered as a part of the image positioning problem for EOS, along with image sensor design and ground image processing system design. Study results show that, with suitable efficiency for ground control point selection and matching activities during data processing, extensive reliance should be placed on use of ground control points for positioning the images obtained from EOS and similar programs.

Forrest, R. B.; Eppes, T. A.; Ouellette, R. J.

1973-01-01

487

Advanced Motor Drives Studies  

NASA Technical Reports Server (NTRS)

This report presents an evaluation of advanced motor drive systems as a replacement for the hydrazine fueled APU units. The replacement technology must meet several requirements which are particular to the space applications and the Orbiter in general. Some of these requirements are high efficiency, small size, high power density. In the first part of the study several motors are compared, based on their characteristics and in light of the Orbiter requirements. The best candidate, the brushless DC is chosen because of its particularly good performance with regards to efficiency. Several power electronics drive technologies including the conventional three-phase hard switched and several soft-switched inverters are then presented. In the last part of the study, a soft-switched inverter is analyzed and compared to its conventional hard-switched counterpart. Optimal efficiency is a basic requirement for space applications and the soft-switched technology represents an unavoidable trend for the future.

Ehsani, M.; Tchamdjou, A.

1997-01-01

488

PSU Case Studies  

NSDL National Science Digital Library

How does one teach ethics? It can be a difficult subject and different fields (medicine, law, and so on) all have different ethical considerations and issues. This fine collection of engineering case studies from the Pennsylvania State University College of Engineering brings together resources from a variety of universities that have worked to address this matter. The cases are divided into separate areas that include Developing and Using Case Studies, General Science Cases, and Research Integrity Cases. Visitors shouldn't miss the bulk of the material covered in the General Engineering Cases area, which includes high-quality and contemplative materials on engineering practice ethics from SUNY-Buffalo and the National Science Foundation. The site is rounded out by a number of helpful cases developed in-house by Penn State engineering students.

2013-04-26

489

Stratospheric project studies climate  

NASA Astrophysics Data System (ADS)

Until now, the World Climate Research Programme (WCRP) has emphasized the ocean-troposphere system in its studies of climate, but in implementing the Stratospheric Processes and Their Role in Climate (SPARC) project in March 1992, the Joint Scientific Committee (JSC) of the WCRP has recognized that one must understand stratospheric behavior in many studies of climate change. For instance, one should consider what effects anthropogenic changes in stratospheric ozone might have on climate. Also, the recent eruption of Mt. Pinatubo in the Philippines has once again illustrated how volcanically induced changes in the stratospheric aerosol veil can influence climate. It is finally becoming clearer that the stratospheric changes resulting from the increasing concentration of greenhouse gases must be considered both in identifying and evaluating greenhouse influences on the troposphere.

490

2007 CEO Compensation Study  

NSDL National Science Digital Library

Charity Navigator provides high-quality information about charities in order "to advance a more efficient and responsive philanthropic marketplace." One of the more recently published studies is the 2007 CEO Compensation Study. Visitors can read this annotated report here in its entirety, and it contains a wealth of information about the subject. In the year 2007, their research shows that the top leaders of the 5242 largest charities in America earn an average salary of $145,270. While this amount may strike some as rather large, the report also notes that CEO compensation accounts for just 3.37% of the average organization's spending. The report contains a number of helpful charts, such as those that list average CEO salary by geographic region and by size of charity.

2007-08-01

491

Study Thermographic Flaw Detection  

NASA Technical Reports Server (NTRS)

The development of thermographic inspection methods for use on aerospace structures is under investigation. Several different material systems, structural geometries and defect types have been included in this study so as to establish a baseline from which future Infrared Thermography(IRT) testing can be made. This study examines various thermal loading techniques in an attempt to enhance the likelihood of capturing and identifying critically sized flaws under 'non laboratory' actual working conditions. Qualification techniques and calibration standards are also being investigated to standardize the thermographic method. In conjunction with the thermographic inspections, advanced image processing techniques including digital filtering and neural networks have been investigated to increase the ability of detecting and sizing flaws. Here, the digitized thermographic images are mathematically manipulated through various filtering techniques and/or artificial neural mapping schemes to enhance its overall quality, permitting accurate flaw identification even when the signal-to-noise ratio is low.

Walker, James L.; Workman, Gary L.

1996-01-01

492

A Wetland Field Study  

NSDL National Science Digital Library

The field projects at this site give students an opportunity to investigate a number of wetland characteristics firsthand: surveying wetland vegetation, soils, water quality and wildlife; documenting the wetland from an artist's perspective; investigating land uses along its periphery; and refining a base map upon which all collected information can be recorded. This resource explains how to organize the field study, thereby securing the interest of the students. It is part of a module that aims to help students get to know the complexities of wetlands, discover wildlife, enjoy the experience of being outdoors, and learn how necessary wetlands are to the health of our environment. For educators and their middle school students, it suggests ways to study wetland characteristics, why wetlands are important, and how students and teachers can help protect a local wetland in any part of the country. An associated set of activities is also available.

493

RF Gun Optimization Study  

SciTech Connect

Injector gun design is an iterative process where the designer optimizes a few nonlinearly interdependent beam parameters to achieve the required beam quality for a particle accelerator. Few tools exist to automate the optimization process and thoroughly explore the parameter space. The challenging beam requirements of new accelerator applications such as light sources and electron cooling devices drive the development of RF and SRF photo injectors. RF and SRF gun design is further complicated because the bunches are space charge dominated and require additional emittance compensation. A genetic algorithm has been successfully used to optimize DC photo injector designs for Cornell* and Jefferson Lab**, and we propose studying how the genetic algorithm techniques can be applied to the design of RF and SRF gun injectors. In this paper, we report on the initial phase of the study where we model and optimize gun designs that have been benchmarked with beam measurements and simulation.

A. S. Hofler; P. Evtushenko; M. Krasilnikov

2007-08-01

494

MIT Security Studies Program  

NSDL National Science Digital Library

Based at the Center for International Studies at MIT, the Security Studies Program is interested in "the integration of technical and political analysis of national and international security problems." Visitors to the site can look over their research agenda, learn about their degree programs, and also look at their interactive calendar. Scholars will definitely want to make their way to the "Program Publications" area. Here they will find the Program's annual report, their research journal, and a monthly newsletter titled "Early Warning". Moving on, visitors should also take a look at some of their working papers, which include "Transforming the Rewards for Military Service" and "The Political Science of Agent Orange". The site is rounded out with a search engine and information about relevant conferences.

495

LOXT mirror design study  

NASA Technical Reports Server (NTRS)

The final report for the large orbiting X-ray telescope (LOXT) high resolution mirror design study is presented. The following tasks were performed: (1) Generation of a reference and alternate preliminary design for the LOXT high resolution mirror assembly, which will meet the LOXT scientific requirements, and are within the present state of the art of materials and fabrication techniques. (2) Measurement, in X-rays, of the scattering properties of a variety of optical flats, embodying materials, coatings, and polishing techniques which might be applicable to the flight configuration LOXT high resolution mirror. (3) Preparation of a procurement specification for a paraboloid test mirror of the size of the innermost paraboloid of the high resolution mirror assembly, including the design requirements for the reference design evolved from this preliminary design study. The results of the engineering and scientific analysis and the conclusions drawn are presented. The procurement specification for the test mirror is included.

Vanspeybroeck, L.; Antrim, W.; Boyd, D.; Giacconi, R.; Sinnamon, G.; Stille, F.

1972-01-01

496

Payload training methodology study  

NASA Technical Reports Server (NTRS)

The results of the Payload Training Methodology Study (PTMS) are documented. Methods and procedures are defined for the development of payload training programs to be conducted at the Marshall Space Flight Center Payload Training Complex (PCT) for the Space Station Freedom program. The study outlines the overall training program concept as well as the six methodologies associated with the program implementation. The program concept outlines the entire payload training program from initial identification of training requirements to the development of detailed design specifications for simulators and instructional material. The following six methodologies are defined: (1) The Training and Simulation Needs Assessment Methodology; (2) The Simulation Approach Methodology; (3) The Simulation Definition Analysis Methodology; (4) The Simulator Requirements Standardization Methodology; (5) The Simulator Development Verification Methodology; and (6) The Simulator Validation Methodology.

1990-01-01

497

Singapore Chinese Health Study  

Cancer.gov

The current research project continues support for a residential cohort of 63,257 middle-aged and older (45 to 74 years of age) Singapore Chinese men and women accrued between 1993 and 1998. At recruitment, each study participant was interviewed in person by a trained interviewer using a structured questionnaire that emphasized current diet assessed via a validated, 165-item food frequency questionnaire.

498

Journal of Millennial Studies  

NSDL National Science Digital Library

This online journal is produced by the Center for Millennial Studies, an organization devoted to archiving apocalyptic literature and analyzing millenarianism. The inaugural issue contains five articles and a book review in .pdf format. These include: "Religion INK.: Tabloid Crucifiction (Whose Apocalypse? When?)," "Jewish Shock-Troops of the Apocalypse: Antichrist and the End, 1200-1600," and "The Mongols and non-believing apocalyptic friends around the year 1260."

499

TexasChildStudy  

Cancer.gov

The Texas Child Study Center is a collaboration between the University of Texas at Austin and Dell Children’s Medical Center. The Center’s postdoctoral fellowship program provides advanced training in clinical services, supervision, and research in evidence-based treatment, group and family therapy, and psychological and neuropsychological assessment with children and adolescents that have emotional and behavioral disorders, as well as children with medical illness.

500

Protein Crystal Quality Studies  

NASA Technical Reports Server (NTRS)

Eddie Snell, Post-Doctoral Fellow the National Research Council (NRC) uses a reciprocal space mapping diffractometer for macromolecular crystal quality studies. The diffractometer is used in mapping the structure of macromolecules such as proteins to determine their structure and thus understand how they function with other proteins in the body. This is one of several analytical tools used on proteins crystallized on Earth and in space experiments. Photo credit: NASA/Marshall Space Flight Center (MSFC)

1998-01-01