2,484 research outputs found
Accurate first principles prediction of O-17 NMR parameters in SiO2: Assignment of the zeolite ferrierite spectrum
No full textO-17 NMR parameters, both the chemical shifts and the quadrupolar parameters, are calculated for SiO2 polymorphs using density functional theory with the generalized gradient-corrected PBE functional. The gauge including projector augmented wave (GIPAW) method (Pickard, C. J.; Mauri, F. Phys. Rev. B 2001, 63, 245101) ensures the reproduction of all electron results while using computationally efficient pseudopotentials. The use of plane-waves permits fully converged calculations to be performed on structures containing 144 atoms in the unit cell, without the need to resort to the cluster approximation. The calculated NMR parameters of cristobalite, quartz, coesite, and faujasite are in excellent agreement with experimental data. This demonstrates that density functional theory is able to reproduce with high accuracy the O-17 NMR parameters in SiO2 systems. This precision is used to assign the spectrum of the zeolite ferrierite. The data calculated for SiO2 are used to confirm that no simple correlation between the chemical shift and Cq NMR parameters and Si-O-Si angle exists, emphasizing the importance of predictive theories in this field
All-electron magnetic response with pseudopotentials: NMR chemical shifts
No full textA theory for the ab initio calculation of all-electron NMR chemical shifts in insulators using pseudopotentials is presented. It is formulated for both finite and infinitely periodic systems and is based on an extension to the projector augmented-wave approach of Blochl [P. E. Blochl, Phys. Rev. B 50, 17 953 (1994)] and the method of Mauri et al. [F. Mauri, B. G. Pfrommer, and S. G. Louie, Phys. Rev. Lett. 77, 5300 (1996)]. The theory is successfully validated for molecules by comparison with a selection of quantum chemical results, and in periodic systems by comparison with plane-wave all-electron results for diamond
Atomic structure of icosahedral B4C boron carbide from a first principles analysis of NMR spectra
No full textDensity functional theory is demonstrated to reproduce the C-13 and B-11 NMR chemical shifts of icosahedral boron carbides with sufficient accuracy to extract previously unresolved structural information from experimental NMR spectra. B4C can be viewed as an arrangement of 3-atom linear chains and 12-atom icosahedra. According to our results, all the chains have a CBC structure. Most of the icosahedra have a B11C structure with the C atom placed in a polar site, and a few percent have a B-12 structure or a B10C2 structure with the two C atoms placed in two antipodal polar sites
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
Observation of psi(3686) -> e(+)e(-)chi(cJ) and chi(cJ) -> e(+)e(-)J/psi
No full textKolcu, Onur Buğra (Arel Author)Using 4.479 x 10(8) psi(3686) events collected with the BESIII detector, we search for the decays psi(3686) -> e(+)e(-)chi(cJ) and chi(cJ) -> e(+)e(-)J/psi, where J = 0, 1, 2. The decays psi(3686) -> e(+)e(-)chi(cJ) and chi(cJ) -> e(+)e(-)J/psi are observed for the first time. The measured branching fractions are B(psi(3686) -> e(+)e(-)chi(cJ)) = (11.7 +/- 2.5 +/- 1.0) x 10(-4), (8.6 +/- 0.3 +/- 0.6) x 10(-4), (6.9 +/- 0.5 +/- 0.6) x 10(-4) for J = 0, 1, 2, and B(chi(cJ) -> e(+)e(-)J/psi) = (1.51 +/- 0.30 +/- 0.13)x10(-4), (3.73 +/- 0.09 +/- 0.25)x10(-3), (2.48 +/- 0.08 +/- 0.16)x10(-3) for J = 0, 1, 2, respectively. The ratios of the branching fractions B(psi(3686) -> e(+)e(-)chi(cJ))/B(psi(3686) -> gamma chi(cJ)) and B(chi(cJ) -> e(+)e(-)J/psi)/B(chi(cJ) -> gamma J/psi) are also reported. Also, the alpha values of helicity angular distributions of the e(+)e(-) pair are determined for psi(3686) -> e(+)e(-)chi(c1,2) and chi(c1,2) -> e(+)e(-)J/psi
Asymptotic Stability of a Plane CJ Detonation Wave
No full text. We study the asymptotic stability of a plane CJ detonation wave under the assumption of small resolved heat release (SRHR). We prove that the solution exists globally and that the solution converges uniformly to a shifted CJ detonation wave as t!+ 1 for initial data which are small perturbations of the CJ detonation wave. The weighted energy method is used to overcome the difficulty arising from the sonic property at the end of the reaction. The SRHR model allows us to treat the non-monotone spike in the profile of the CJ detonation wave by the characteristic energy estimate. Key words. CJ detonation, shock wave, traveling wave, sonic point, asymptotic behavior, weighted energy estimate, characteristic energy estimate. AMS(MOS) subject classifications. 35L65, 35B40, 35B50, 76L05, 76J10. Acknowledgments. The author is grateful to Prof. T.-P. Liu for pointing out the reference of Matsumura and Nishihara to her. This work was partially supported by ONR N00014-92-J-1890. 1 Introduc..
Observation of chi(cJ) -> 4K(S)(0)
No full textKolcu, Onur Buğra (Arel Author)By analyzing (448.1 +/- 2.9) x 10(6) psi(3686) events collected with the BESIII detector operating at the BEPCII collider, the decays of chi(c)(J) -> 4K(S)(0) (J = 0, 1, 2) are observed for the first time with statistical significances of 26.5 sigma, 5.9 sigma and 11.4 sigma, respectively. The product branching fractions of psi(3686) -> gamma chi(cJ), chi(cJ) -> 4K(S)(0 )are presented, and the branching fractions of chi(cJ) -> 4K(S)(0) decays are determined to be B-chi c0 -> 4KS0 = (5.76 +/- 0.34 +/- 0.38) x 10(-4), B-chi c1 -> 4KS0 = (0.35 +/- 0.09 +/- 0.03) x 10(-4) and B-chi c2 -> 4KS0( )= (1.14 +/- 0.15 +/- 0.08) x 10(-4), where the first uncertainties are statistical and the second are systematic, respectively
Theoretical investigation of moganite
No full textThe structure and properties of two different modifications of moganite have been studied using density functional theory, and the results have been compared to quartz. It is shown that the enthalpy difference between quartz and moganite, whose structure can be understood as Brazil twinning of quartz on a unit cell length scale, is negligible. This explains the significant amount of moganite in fine-grained quartz samples, as well as the frequent occurrence of Brazilian twinning in quartz. The compression mechanism of moganite has been elucidated, and it is argued that moganite is significantly more compressible than quartz. Observed and calculated NMR spectra are compared, and it is found that the bonding in quartz and moganite is very similar, consistent with the results of a Mulliken population analysis. The elastic stiffness coefficients of moganite have been predicted, and it is shown that formal-charge shell model interatomic potentials appear to be more transferable from quartz to moganite than partial-charge rigid ion equivalents. © 2005 E. Schweizerbart'sche Verlagsbuchhandlung
Calculation of NMR chemical shifts for extended systems using ultrasoft pseudopotentials
No full textWe present a scheme for the calculation of magnetic response parameters in insulators using ultrasoft pseudopotentials. It uses the gauge-including projector augmented wave method to obtain all-electron accuracy for both finite and infinitely periodic systems. We consider in detail the calculation of NMR chemical shieldings. The approach is successfully validated first for molecular systems by comparing calculated chemical shieldings for a range of molecules with quantum chemistry results and then in the solid state by comparing O17 NMR parameters calculated for silicates with experiment. © 2007 The American Physical Society
"These signs forerun the death or fall of kings": renegotiating masculinities and centrality in Shakespeare's second tetralogy through adaptation, direction and performance (PhD Thesis): [Appendix 1.4] Fall of Kings (2018) - Rehearsal and Production Photographs
No full textThis item contains appendices content relating to the PhD thesis, "These signs forerun the death or fall of kings": renegotiating masculinities and centrality in Shakespeare's second tetralogy through adaptation, direction and performance, by doctoral candidate CJ Turner-McMullan.Fall of Kings is an adaptation of William Shakespeare's Richard II, exploring performed and embodied representations of masculinities, and how performance may subvert binary dichotomies and gendered power onstage. The production was photographed during rehearsals at Bath Spa University and performances at Burdall's Yard, Bath in March 2018.Adapted and directed by CJ Turner-McMullanFight Direction // Russell Eccleston and Tiffany RhodesLighting Design // Annabel EllisSound Design and Composition // Edward TerryPerformers // Toby Underwood, Russell Eccleston, Gabrielle Finnegan, Ross Scott, James Leyshon, Adam Lloyd-James, Mike Harley, Kian Keanu PollardReproduced with permission from CJ Turner-McMullan and Sam Chandler (photographers).All media is copyright restricted. No unauthorised use or distribution without consent of the author. Use of this repository acknowledges cooperation with its policies and relevant copyright law.</p
- …
