bluuebunny/crossref_metadata_2025_split huggingface dataset:
13CP/MAS NMR Study of Motion and Local Structure of Phenethyl- ammonium Ion in [C6H5CH2CH2 NH3]2PbX4(X = Cl, Br, I)
Authors: Ueda Takahiro , Shimizu Katsuyuki , Ohki Hiroshi , Okuda Tsutomu 
Published: February 2015

Abstract
Ionic motion and local structure of phenethylammonium ion (C6H5CH2CH2NH3+) in a series of phenethylammonium lead(II) halides, [C6H6CH2CH2NH3]2PbX4 (X = Cl, Br, I) were studied by means of 13C cross polarization/magic angle sample spinning (CP/MAS) NMR technique. Among the three salts, remarkable differences in the spectra were observed in the signals corresponding to the phenyl carbons. The peaks from C2, C3, C5, and C6 in the phenyl group were split into three for the chloride and into two for the bromide, although in the iodide those were observed as a single peak. Coalescence of those peaks, as well as line broadening were observed on heating. This indicated that peak split brings about disorder of the orientation in the phenyl group around the C1-C4 axis, suggesting to have three and two orientations for the chloride and the bromide, respectively. Above room temperature the phenyl group undergoes chemical exchange among these orientations, and at higher temperature, reorientation with a large amplitude takes place around its axis. The apparent activation energies of the reorientation of the phenyl group for the chloride and bromide were estimated from the temperature dependence of the linewidth of the resonance peaks to be about 24 kJ mol-1 , 25 kJ mol-1 , respectively, which is similar to in the iodide (25.0 kJ mol-1). Ab initio molecular orbital energy calculation was carried out to evaluate the potential barrier of the internal rotation of the phenyl group in a free phenethylammonium ion. The intramolecular interaction was evaluated to be 13.9 kJ mol-1 from the calculation, and the intermolecular interaction results to be 10 kJ mol-1 .
Solid State Reaction Study of the System Li2CO3/Fe2O3
Authors: Berbenni V. , Marini A. , Capsoni D. 
Published: February 2015

Abstract
A thermoanalytical (TGA/DSC) and diffractometric (XRD) study has been performed on the solid state reaction system Li2CO3 -Fe2O3 in the x Li range 0.10±0.50. A detailed analysis of the results shows that the data are in agreement with a reaction model where the carbonate decomposition is regulated by the formation of both LiFeO2 and LiFe5O8 , and the relative amount of the two phases depends on the initial composition. The DSC evidence offers the possibility to directly quantify the LiFe5Ox phase. Furthermore it allows one to obtain the enthalpies of formation of both LiFeO2 and LiFe5O8 .
Field-Swept NMR Spectra of 11B in Pyrex Glass and 93Nb in NbN Perturbed by Quadrupole Interaction
Authors: Yoshida H. , Nishihara H. , Yokota S. , Ohyanagi M. , Nakaoki T. 
Published: February 2015

Abstract
NMR experiments of 11B by both field-swept and high-resolution NMR are reported to probe the electric field gradient at boron sites and its distribution in Pyrex glass. Both spectra are successfully interpreted with the same set of parameters. It is stressed that field-swept NMR experiments to observe total powder spectrum can be helpful to get information on electric field gradients and asymmetry pa-rameters if there exist many nonequivalent sites of atoms, since satellite transitions are affected by the larger first-order quadrupole effect. Field-swept NMR of 93Nb in superconducting NbN powder, prepared by self-propagating high-temperature synthesis, is also reported. A very broad field-swept spectrum disturbed by quadrupole interaction has been observed. The spectrum is simulated by assuming distributions in electric field gradient and Knight shift at Nb sites. It is stressed that a combination of experiments at separated frequencies is important.
Powder Zeeman NQR Study on the Absorption Forms for Nuclear Spin 5/2
Authors: Ege O. , Nishijima S. , Kimura E. , Akiyama H. , Hamai S. , Negita H. 
Published: February 2015

Abstract
For nuclei which have a nuclear spin of 5/2 and exhibit a small asymmetry parameter of the electric field gradient (ƞ) at the nuclear site, line shapes of the Powder Zeeman NQR (PZNQR) spectra based on the transition between the energy levels m1 = ± 1/2 and ± 3/2 (the lower frequency line) were studied by means of computer simulations and experiments. (i) When an ƞvalue is very small (type 1; ƞ= 0), the line shape exhibits two shoulders like the style of the American football player. (ii) While an ƞvalue is small (type 2; 0 < ƞ< around 0.01) but not zero, the line shape has two small peaks which are symmetrically located on the shoulders, as in the case of the small ƞtype of spin 3/2. (iii) When an ƞvalue is not small (type 3; around 0.01 < ƞ), the line shape has two symmetrical dips in stead of the peaks, which are also similar to the case of not small ƞ type of spin 3/2. As the ƞvalue increases from around 0.01, the two dips grow and reach the maximum at the ƞvalue of 0.349, and then become smaller and obscure in the range of ƞlarger than 0.349.
The observations of PZNQR spectra were performed for several compounds including the 127I and/or 121Sb nuclei to estimate the ƞvalues, and gave the results as follows: very small for 127I (207.683 and 209.133 MHz, at 77 K) in Snl4; very small for 127I (176.496 and 177.438 MHz, at 77 K) in Gal3; small for 127I (265.102 MHz, at 77 K) in CH3I; 0.33 for 127I (247.69 MHz, at 77 K) in C2H5I; 0.27 for 121Sb (58.23 MHz, at 290 K) in SbCl3. The estimated ƞvalues were compared to those obtained from the frequencies of two NQR lines for spin 5/2. They were in good agreement with each other for the small region of ƞ, though somewhat large disagreements were seen in the cases of not small ƞvalues.
Nuclear Quadrupole Interaction at 187W(β-)187Re in Tungsten Compounds
Authors: Schmidt Pit , Soldner Torsten , Tröger Wolfgang , Ni Xinbo , Butz Tilman , Blaha Peter 
Published: February 2015

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The nuclear quadrupole interaction at 187W(β-)187 Re was determined by time differential perturbed angular correlation in WC, WS2, WSe2, WSi2, and CaWO4 to be (at 300 K): vQ = 335.9(2), 1094.9(1), 10311), 1131,5( 1), and 1085.9( 1) MHz, respectively. The asymmetry parameter ƞwas zero in all cases. For WSe2 and CaWO4 the temperature dependence of the nculear quadrupole interaction was determined between 300 K and about 900 K. Ab initio calculations of electric field gradients, using the WIEN95-code, were carried out for WC, WS2, WSe2, and WSi2 at W-sites and Re-impurities, and for CaWO4 at W-sites. Good agreement with experimental data was found.
Evaluation of the 57mFe Quadrupole Moment from Hartree-Fock Calculations
Authors: Hagelberg F. , Das T. P. 
Published: February 2015

Abstract
Two theoretical evaluations of 57mFe quadrupole moment (Q), based on different formalisms, namely the Hartree-Fock theory and the Linearized Augmented Plane Wave method have yielded results differing by a factor of two. In both cases, Q was obtained from experimental quadrupole interaction frequencies through investigation of the Electric Field Gradients at the nuclear site of the 57mFe probe. It is the purpose of the present work to reexamine the earlier Hartree-Fock approach. In particular, the earlier model is extended through a more realistic description of the environment of 57mFe in the respective experiments, as well as through inclusion of electron correlation effects.
Ab initio Study of Nitrogen-14 Nuclear Quadrupole Coupling and NMR Signal Linewidths in Some Azoles
Authors: Jaszuński Michał , Rizzo Antonio 
Published: February 2015

Abstract
Ab initio values of Nitrogen 14N Nuclear Quadrupole Coupling Constants (NQCC's) are calculated for a series of methyl-substituted azoles in the Multiconfigurational SCF (MCSCF) approximation. The four triazoles and two tetrazoles studied here are all isoelectronic. This enabled us to use the same level of approximation - basis set and active space -for all the molecules. The computed NQCC's are used to estimate the relative widths of the 14N NMR signals, assuming an identical effect of molecular tumbling for all the nuclei in a molecule and neglecting solvent effects. The linewidths for the unsubstituted N atoms are, in agreement with experiment, much larger than for the methyl-substituted N atom. For the 1-methyl-tetrazole we present also the NMR shielding and spin-spin coupling constants and discuss in some more detail the dependence of all calculated NMR properties on the basis set and correlation effects.
Ab initio Calculations of Electric Field Gradients for Transition Metal Impurities in TiO2
Authors: Sato K. , Akai H. , Minamisono T. 
Published: February 2015

Abstract
We present ab initio calculations of EFGs at impurities in a TiO2 crystal. They are directly calculated from the self consistent charge distribution which is determined by the KKR method within the muffin-tin approximation and based on the local density approximation. Impurities in the crystal are simulated by the super-cell method. Considering the charge state of Sc, Ti, Nb, Cd, Ta impurities in the TiO2 , the experimental values were well reproduced. The electronic structure of these impurities is discussed by analyzing the calculated density of states.
Dynamics of Liquid Crystals by Means of 2 H-NMR: a Comparison between 4,4'-bis(hexyloxy)azoxybenzene and the Derivative Pd(II) Complex AZPAC
Authors: Calucci Lucia , Forte Claudia , Geppi Marco , Veracini Carlo Alberto 
Published: February 2015

Abstract
In the present work we report a molecular dynamics investigation of the two mesogens 4,4'-bis(hexyloxy)azoxybenzene (HL) and its Pd(II) acetylacetonate derivative Azpac in their nematic phases. Deuterium Zeeman and quadrupolar spin-lattice relaxation times have been measured at 46.04 MHz on two isotopomers of Azpac (Azpac-d4 and Azpac-d26 , deuteriated on the aromatic core and on the alkoxy chains, respectively) and on HL-d4 , an isotopomer of HL partially deuteriated on the aromatic core, by means of the Wimperis pulse sequence. The spectral densities obtained from the measured relaxation times are discussed in terms of internal and overall molecular motions. A small step rotational diffusion model for the overall molecular motions, superimposed on a free rotational model for internal motions, allowed diffusion coefficients for molecular spinning and tumbling and for phenyl ring rotations to be derived for HL; the same models were used in describing the dynamics of Azpac.
Phase Transition and Crystal Dynamics of 4-Bromobenzyl Alcohol
Authors: Hashimoto Masao , Monobe Yuko , Terao Hiromitsu , Niki Haruo , Mano Koichi 
Published: February 2015

Abstract
For the title compound a phase transition from Phase II to Phase I (low and room temperature phases, respectively) was found at ca. 217 K. The temperature dependence of the 81Br NQR frequency and that of the dielectric constant showed anomalies at ca. 195 K that were tentatively attributed to a higher order phase transition. A similar anomaly was found at ca. 218 K for 4-chlorobenzyl alcohol which showed a II-I transition at 236 K. The dielectric dispersion observed for both compounds at low temperatures indicates an excitation of a molecular motion with the dielectric relaxation rate of ca. 1 kHz. The temperature dependence of the 81Br NQR frequencies of 2-and 3-bromobenzyl alcohol, measured at T > 77 K, gave no evidence of phase transition in their crystals.
2H and 195 Pt NMR Studies of Molecular and Electron Spin Dynamics in Paramagnetic [Cu(H2O)6][PtCl 6]
Authors: Iijima Takahiro , Orii Kengo , Mizuno Motohiro , Suhara Masahiko 
Published: February 2015

Abstract
The temperature dependences of 2H and 195Pt NMR spectra and the spin-lattice relaxation time T1 were measured for [Cu(H2O)6][PtCl6]. From the simulation of 2H NMR spectra, the jump rate of 180° flips of the water molecules (k), the nuclear quadrupole interaction parameters (e2Qq/h, ƞ) and the electron-nucleon dipolar interaction parameter (vD) were obtained. By measuring 2H T1, k was estimated in the temperature range where the spectrum is insensitive to the motion of the water molecules. Above the phase transition temperature, the pre-exponential factor k0 = 8 x1011 s-1 and the activation energy Ea = 15 kJmol-1 for 180° flips of the water molecules were obtained from the spectral simulation and T1. 195Pt NMR spectra showed an axially symmetric and unsymmetric powder pattern of the chemical shift anisotropy at the high and low temperature phase, respectively. For the deuterated compound, the correlation times of the electron spin in Cu2+ were estimated from 195Pt T1 and the activation energy for jumping between the different configurations of Jahn-Teller distortion Δ = 200 K was obtained.
Temperature Dependence of 2H Quadrupole Coupling Constants in 2H2O and Ionic Motions in Crystalline [M(2H2O)6] [SnCl6] (M: Mg, Ca), Studied by 2H NMR and Neutron Powder Diffraction
Authors: Yoshida Naohiro , Onoda-Yamamuro Noriko , Ishimaru Shin'ichi , Horiuchi Keizo , Ikeda Ryuichi 
Published: February 2015

Abstract
The temperature dependence of 2H NMR spectra was measured at 130-430 K on [M(D2O)6] [SnCl6] (M : Mg, Ca) (rhombohedral, space group: R3̅), and neutron powder diffraction on the Mg salt was performed at room temperature. Based on the accurate orientation of D2O molecules in an octahedral cation, spectra with a large asymmetry parameter η, observed around 200 K, were explained by a model of 180° flip of water molecules. Another motional narrowing observed above room temperature was assigned to a cationic overall reorientation about the C3-axis.
209Bi NQR and Magnetic Properties of Bismuth Oxide-Based Compounds
Authors: Kravchenko E. A. , Orlov V. G. , Hai Fam Suan , Kargin Yu. F. 
Published: February 2015

Abstract
The NQR line shapes of 209Bi in the α-Bi2O3-based mixed oxides Bi2O3 • 2M2O3 (M = Al, Ga). Bi2O3 • 3GeO2, and 2Bi2O3 • 3GeO2 are recorded in zero and weak magnetic fields (Hext < 500 Oe) and compared with the results of computer simulation. Splittings and line shape asymmetry, exhibited by the resonances, suggest that internal magnetic fields, similar to those earlier reported for α-Bi2O3 and Bi3O4Br, may exist in these compounds.
In the spectra of single crystal Bi4Ge3O12, the line multiplicity in external magnetic fields is higher than simulated, which might results from domains in the crystal.
In external magnetic fields a notable increase in the line intensity was observed, the effect depending on the mutual orientation of the EFG axes and the fields perturbing the nuclear spin system.
Oxygen Content Dependence of 63Cu(1) NQR and Proton NMR in Hydrogen-Doped Antiferromagnetic YBa2Cu3O6+xHy
Authors: Niki Haruo , Kano Kikuhiro , Takase Mitsuhiro , Majikina Kensei , Yagasaki Katsuma , Shinohara Takeshi , Omori Mamoru , Tomiyoshi Shoichi , Akiba Etsuo 
Published: February 2015

Abstract
The oxygen content dependence of 63Cu NQR at the Cu(1) site and proton NMR have been measured in the antiferromagnetic phase of powdered samples of hydrogen-doped YBa2Cu3O6+xHy (0.07 <̲ x <̲ 0.17 and y ≈ 1) from 4.2 to 90 K. The spectrum of 1H NMR is a single line and the line width increases below 15 K due to magnetic interactions. The enhancements of T1
-1 and T2
-1 of 63Cu(l)NQR occur around 35 and 15 K, respectively. These enhancements increase with increasing oxygen concentration. The maximum values of T1
-1 and T2
-1 for the sample with x = 0.17 reach 200 sec-1 and more than 7 msec-1, respectively. The predominant source for the relaxation mechanism of 63Cu(l) NQR and the line broadening of 1H NMR are found to be the fluctuating magnetic field due to the staggered Cu2+ moments.
NQR 127I Spectroscopy of Layered Inorganic Compounds Intercalated with Aromatic Amines
Authors: Babushkina T. A. , Seryukova I. V. 
Published: February 2015

Abstract
NQR spectroscopy was used to study the intercalating influence on the iodine electric field gradient of lead(ll) and cadmium(ll) iodides. We used pyridine, piperidine, aniline and quinoline, as guest substances. In the intercalates the NQR frequencies and their dependence on temperature in different crystalline phases were studied. The peculiarities of chemical bonds and crystal structures were discussed.
63Cu NQR and Structural Studies of Complexes Formed Between Cu(I) Halides and tris(o-methoxyphenyl)- or tris(p-tolyl)phosphine Ligands
Authors: Ramaprabhu Sundara , Amstutz Nahid , Lücken Edwin A. C. , Bernardinelli Gérald 
Published: February 2015

Abstract
The crystal structure of [tri(o-methoxyphenvl)phosphine]2 Cu2Br2 shows it to be a halogen-bridged dimer with three-coordinated Cu (I) sites. The 63Cu NQR frequency of the corresponding chloride indicates that it has a similar structure. The 63Cu NQR frequencies of the complexes of tri(p-tolyl)phosphine, L3Cu2X2 , with cuprous chloride and bromide are consistent with their having halogen-bridged structures with both three- and four-coordinated Cu(I) sites analogous to those formed by triphenyl-phosphine and tri(m-tolyl)phosphine. Cu(I) sites. [CuBr(P(C7H7O)3]2 ; Triclinic, P l̄, Z=2, a = 8.969(1), b= 10.510(2), c=l 1.428(2) Å, α=99.46(l), β=91.95(\), γ= 104.17(1)°, R=3.5%, Rω=2.2% .
Comparison of Running Economy Values While Wearing No Shoes, Minimal Shoes, and Normal Running Shoes
Authors: Cochrum Robbie G. , Connors Ryan T. , Coons John M. , Fuller Dana K. , Morgan Don W. , Caputo Jennifer L. 
Published: February 2015

Abstract
Cochrum, RG, Connors, RT, Coons, JM, Fuller, DK, Morgan, DW, and Caputo, JL. Comparison of running economy values while wearing no shoes, minimal shoes, and normal running shoes. J Strength Cond Res 31(3): 595–601, 2017—The purpose of this study was to quantify differences in running economy (RE) at 50 and 70% of each subject's velocity at V̇o
2max (vV̇o
2max) across barefoot and 2 mass, stack height, and heel-to-toe-drop controlled footwear conditions (minimal shoes and normal running shoes) in 9 recreational distance runners (mean age 26.8 ± 6.8 years). Over 3 days, subjects ran in one of the footwear conditions while RE (oxygen consumption) and step frequency were measured at each speed with a 5-minute rest between each trial. A 2-way repeated-measures multivariate analysis of variance (p ≤ 0.05) and Bonferroni-adjusted follow-up analyses revealed that RE was not significantly different across footwear conditions at either speed. However, those running barefoot exhibited a higher step frequency than when running in minimal (50%, p = 0.007; and 70%, p < 0.001) and standard footwear conditions (70% only, p < 0.001). Higher step frequencies were also exhibited by those running in minimal versus standard footwear (70% only, p = 0.007). Thus, RE is not affected by footwear or running barefoot in those with experience running in minimal-type footwear. Significant adjustments in step frequency when alternative footwear was introduced may help explain why RE was statistically maintained during each footwear and speed condition across but not between subjects. Therefore, determination of footwear for the enhancement of RE should be based on individual physical characteristics and preferences rather than a global recommendation of an economical running shoe.
Implementation of an Ability-Based Training Program in Police Force Recruits
Authors: Orr Robin M. , Ford Kelsie , Stierli Michael 
Published: February 2015

Abstract
Orr, RM, Ford, K, and Stierli, M. Implementation of an ability-based training program in police force recruits. J Strength Cond Res 30(10): 2781–2787, 2016—Currently, police recruit physical training programs generally use group-based runs of a “1 size fit all” approach. The aim of this study was to assess the impact of an ability-based training (ABT) program, as derived from the 30-15 Intermittent Fitness Assessment, on the metabolic fitness and injury rates of police recruits undergoing basic training. Police recruits completing two different stages of training (session 1: n = 54 and session 2: n = 233) were randomly assigned to either a control group (CG) (standard group running) or an intervention group (IG) (ABT program). Physical training was completed once a week over a 10-week period. Aerobic fitness was measured through 20-m progressive shuttle run test performance. Injury data were captured through formal accident and incident forms. Results found that aerobic fitness was maintained but not significantly improved in both groups for session 1, with no significant differences between the groups after training. In session 2, both groups significantly improved their aerobic fitness (p < 0.001), whereas the IG to a greater degree, with no significant differences between the groups after training. There were no significant differences in injury rates between groups (session 1: χ2(1) = 1.533, p = 0.216; session 2: χ2(1) = 1.252, p = 0.263). However, the IGs had a significantly lower relative risk (RR) of injury when compared with the CGs (group 1: RR = 0.31, p = 0.28; group 2: RR = 0.59, p = 0.24). The results suggest that coaches may benefit from implementing ABT programs in tactical populations and achieve the same or better fitness gains with a lower risk of injuring recruits.
New information on distribution of a marine leech, Pontobdella muricata (Linnaeus, 1758), from the Mediterranean coast of Turkey
Authors: Bulguroğlu Saadet Yağmur , Korun Jale , Gökoğlu Mehmet 
Published: February 2015

New information on distribution of marine leech, Pontobdella muricata (Linnaeus, 1758) is given here. One leech was observed on the dorsal surface of Thornback Ray, Raja clavata (Linnaeus, 1758) that was caught in 2013 in the Antalya, Turkey. This is a new record for the eastern Mediterranean coast of Turkey.
Cadmium Chloride Assisted Re-Crystallisation of CdTe: The Effect on the CdS Window Layer
Authors: Abbas Ali , Kaminski Piotr , West Geoff , Barth Kurt , Sampath WS , Bowers Jake , Walls John M. 
Published: February 2015

ABSTRACTThe cadmium chloride annealing treatment is an essential step in the manufacture of efficient thin film CdTe solar cells. In previous work we have shown that the primary effect of the treatment is to remove high densities of stacking faults from the as-deposited material. Use of density functional theory has shown that some of the higher energy stacking faults are hole traps. Removal of these defects dramatically improves cell efficiency. In this study we focus on the effect of the activation treatment on the underlying n-type cadmium sulphide layer. A range of techniques has been used to observe the changes to the microstructure as well as the chemical and crystallographic changes as a function of treatment parameters. Electrical tests that link the device performance with the micro-structural properties of the cells have also been undertaken. Techniques used include High Resolution Transmission Electron Microscopy (HRTEM) for sub-grain analysis, EDX for chemical analysis and XPS and SIMS for composition-depth profiling. By studying the effect of increasing the treatment time and temperature, we will show that the cadmium sulphide layer depletes to the point of complete dissolution into the absorber layer. We will also show that chlorine penetrates and decorates the grain boundaries in the cadmium sulphide. In addition we will show that chlorine builds up at the heterojunction and concentrates in voids at the cadmium telluride/cadmium sulphide interface. A combination of these effects damages the electrical performance of the solar cell.