1,333 research outputs found
Electric and Magnetic-properties of the Aromatic 60-carbon Cage
No full textWe report the use of large supercomputer resources to perform the first ab initio calculations on the polarisability and magnetisability of C60 and its smaller analogue C202+. It is found that both molecules have the high polarisability characteristic of π systems and the diamagnetic magnetisability typical of aromatic molecules. Insofar as it is possible to extrapolate to the basis-set limit, the calculations predict net diamagnetism for the clusters, and a diamagnetic effect on the NMR chemical shift of an encapsulated atom
Favorable entropy of aromatic clusters in thermophilic proteins
No full textAromatic clusters, found with increased frequency in a set of thermophilic proteins, confer an entropic advantage over mesophilic analogues through introduction of large-amplitude oscillations; this is a source of improved free energy at high temperatures
Development Of A Preliminary Lifing Analysis Tool For The F135-PW-100 Engine
No full textIn the near future the Royal Netherlands Air Force will replace their fleet of F-16’s with the F-35. In the past the NLR has aided the Air Force with life cycle and deterioration analysis work on the F100-PW-220 engine, which powers the F-16. Understanding the physical system of the engine allows for on-condition maintenance. The same is preferred for the F135-PW-100 engine powering the F-35. Therefore, a preliminary lifing analysis tool has been developed for the F135-PW-100 engine rotor blades, based on open source literature. Aerospace Engineerin
Localisation and reversal of paratropic ring currents in molecules with formal anti-aromatic electron counts
No full textThe aromatic character of the six smallest members of the of alpha,omega-bicyclopentadiene-polyacene series (1(n)) has been assessed using magnetic and energetic criteria. Current density maps (CTOCD-DZ/6-31G**//B3LYP/6-31G**) show that. along the series, the ring current changes from paratropic in pentalene (1(0)) and s-indacene (1(1)), through quenched in 1(2) and 1(3), to diatropic in 1(4) and 1(5). These changes are rationalised in terms of orbital contributions to current. Valence bond calculations (VB/6-31G//B3LYP/6-31G**) in which the pi system is composed of strictly atomic p-orbitals, show that the electronic structures in these homologous series can be described in terms of the two closed-shell Kekule resonance structures for the smallest molecules, but that in the larger molecules allyl-polyacene-allyl biradical structures prevail, owing to the larger resonance energies. This trend in electronic structure parallels the switch from paratropic to diatropic character
0.85 PW laser operation at 3.3 Hz and high-contrast ultrahigh-intensity λ = 400 nm second-harmonic beamline
No full textWe demonstrate the generation of 0.85 PW, 30 fs laser pulses at a repetition rate of 3.3 Hz with a record average power of 85 W from a Ti:sapphire laser. The system is pumped by high-energy Nd:glass slab amplifiers frequency doubled in LiB3O5 (LBO). Ultrahigh-contrast λ = 400 nm femtosecond pulses were generated in KH2PO4 (KDP) with>40% efficiency. An intensity of 6.5 × 1021 W∕cm2 was obtained by frequency doubling 80% of the available Ti:sapphire energy and focusing the doubled light with an f∕2 parabola. This laser will enable highly relativistic plasma experiments to be conducted at high repetition rate
Shifting attention in viewer- and object-based reference frames after unilateral brain injury
No full textThe aims of the present study were to investigate the respective roles that object- and viewer-based reference frames play in reorienting visual attention, and to assess their influence after unilateral brain injury. To do so, we studied 16 right hemisphere injured (RHI) and 13 left hemisphere injured (LHI) patients. We used a cueing design that manipulates the location of cues and targets relative to a display comprised of two rectangles (i.e., objects). Unlike previous studies with patients, we presented all cues at midline rather than in the left or right visual fields. Thus, in the critical conditions in which targets were presented laterally, reorienting of attention was always from a midline cue. Performance was measured for lateralized target detection as a function of viewer-based (contra- and ipsilesional sides) and object-based (requiring reorienting within or between objects) reference frames. As expected, contralesional detection was slower than ipsilesional detection for the patients. More importantly, objects influenced target detection differently in the contralesional and ipsilesional fields. Contralesionally, reorienting to a target within the cued object took longer than reorienting to a target in the same location but in the uncued object. This finding is consistent with object-based neglect. Ipsilesionally, the means were in the opposite direction. Furthermore, no significant difference was found in object-based influences between the patient groups (RHI vs. LHI). These findings are discussed in the context of reference frames used in reorienting attention for target detection
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Salmon plasma protein to inhibit protease enzymes and enhance surimi gelation
No full textThe ability of salmon plasma protein (SPP) obtained from Chinook salmon at the Klaskanine Fish Hatchery (Astoria, OR) to inhibit protease enzymes found in Pacific whiting (PW) surimi and salmon mince as well as the effect of SPP on the gelation properties of PW surimi under various heating conditions was investigated. The first study focused on the biochemical aspects of SPP, including enzyme and autolysis inhibition, stability, and molecular weight determination through inhibitor staining. The second study focused on the effects of SPP on PW surimi gelation using various heating treatments to isolate the activity of both protease enzymes and transglutaminase (TGASE)
The results indicated that SPP contains both cysteine and serine protease inhibitors and effectively inhibits autolysis in both PW surimi and salmon mince. As little as 0.25% SPP inhibited PW surimi autolysis by about 90%, suggesting that low concentrations SPP could be effective when added to PW surimi. In addition, both cysteine and serine protease inhibitors in SPP exhibited good thermal, pH and salt stability. As little as 0.5% addition of SPP significantly improved the gel strength of PW surimi that was rapidly heated to 60°C and held at that temperature for 30 min before rapidly heating to 90°C in order to isolate protease enzyme activity. Analysis of TCA-soluble peptide analysis showed no significant proteolytic activity in this gel after SPP was added. One percent addition of SPP was shown to significantly improve the gel strength of PW surimi that was held at 25°C for 2 hr before being rapidly heated to 90°C in order to isolate TGASE activity. This suggests that SPP may contain its own TGASE activity in addition to endogenous TGASE present in PW surimi. These results were confirmed by SDS PAGE and scanning electron microscopy
Supplementary Data: Spectral Control via Multi-Species Effects in PW-Class Laser-Ion Acceleration
No full textSupplementary materials for our paper "Spectral Control via Multi-Species Effects in PW-Class Laser-Ion Acceleration".
Additional high-resolution, raw HDF5 files using the openPMD standard (DOI:10.5281/zenodo.1167843) increase simulation output data to 4.7 TByte and are available from the corresponding author upon reasonable request.This project received funding within the MEPHISTO project (BMBF-Förderkennzeichen 01IH16006C)
Wall-pressure-velocity transfer kernel in high Reynolds number turbulent channel flows
No full textSince wall-pressure fluctuations would form a practically-robust input to a real-time active controller of wall-bounded turbulence, it is of high practical interest to study the scaling behavior of the wall-pressure-velocity coupling. This work investigates the coupling of the wall-pressure fluctuations with the streamwise and wall-normal velocity fluctuations. Both the gain (or coherence) and phase spectra of the wall-pressure-velocity transfer kernel are assessed using a comprehensive database, available from direct numerical simulations of turbulent channel flow. With data spanning a decade in friction Reynolds number Reτ ∼ 550-5200, a 1D analysis (in terms of the streamwise wavelength, λx) reveals that the streamwise velocity and wall-pressure are most strongly coupled at a self-similar wall-scaling of λx/y ≈ 14. For the wall-normal velocity component, the strongest coupling appears at approximately half this ratio (λx/y ≈ 8.5). An analysis of the kernel's phase demonstrates that both the coherent fluctuations of streamwise and wall-normal velocity obey a forward-leaning inclination angle of α ≈ 30◦. When extending the analysis to 2D (as a function of λx and λz), the peak-coherence for pw and u still resides close to λx/y ≈ 14 and is reasonably symmetric around λx/λz = 2.3. The 2D coherence for pw and v peaks around λx/λz = 1.0. Both the 2D coherence for pw and u, and pw and v, adhere to a wall-scaling with y. Scaling behaviours identified in this work will aid the efficacy of real-time controllers, by for instance the implementation of data-derived FIR filters to only control velocity structures that are captured through wall-pressure measurements.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Aerodynamic
Kościół katedralny pw. Wniebowzięcia Najświętszej Maryi Panny i Polonia w Charkowie: krótki szkic historyczny (XIX wiek)
No full textCathedral church of Assumptoin of the Blessed Virgin Marry a short historical draft (19th century). The author of the article presents a short outline of the cathedral church of Assumption of the Blessed Virgin Marry in Kharkiv since the moment it was built to its ceremonial cosercation in June 26, 1892 by the bishop of Molyhowska Diocese Albin Simon. Building of the church has been shown on the background of functioning of Polish community in Kharkiv in the 19th century which from a small group of believers managed transform into an important part of the citizens of the city. The cathedral church of Assumption of the Blessed Virgin Marry was a rock for Poles’ activities leaving in Kharkiv. The church survived till today and it adrous the city centre as an architectural jewel.Kościół katedralny pw. Wniebowzięcia Najświętszej Maryi Panny i Polonia w Charkowie: krótki szkic historyczny (XIX wiek). Autorka w przedstawionym artykule przybliża krótki zarys historii kościoła katedralnego pw. Wniebowzięcia Najświętszej Maryi Panny w Charkowie od czasu jego wzniesienia do chwili jego uroczystego poświęcenia 26 lipca 1892 roku przez biskupa pomocniczego diecezji mohylowskiej Franciszka Albina Simona. Budowa świątyni została ukazana na tle funkcjonowania w Charkowie w XIX wieku społeczności polskiej, która z niewielkiej garstki wiernych zdołała przekształcić się w niezwykle istotną część składową mieszkańców miasta. Ostoją dla działalności Polaków mieszkających w Charkowie był kościół katedralny pw. Wniebowzięcia Najświętszej Maryi Panny, który przetrwał do czasów obecnych, i dziś, jako perła architektury sakralnej, zdobi centrum miasta
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