Search results for "Proton"
showing 10 items of 5886 documents
α decay of the πh11/2 isomer in Ir164
2014
The α -decay branch of the πh 11 / 2 isomer in 164 Ir has been identified using the GREAT spectrometer. The 164 Ir nuclei were produced using the 92 Mo( 78 Kr ,p 5 n ) 164 Ir reaction and separated in flight using the recoil ion transport unit (RITU) gas-filled separator. The measured α -decay energy of 6880 ± 10 keV allowed the excitation of the πh 11 / 2 state in 160 Re to be deduced as 166 ± 14 keV. The half-life of 164 Ir was measured with improved precision to be 70 ± 10 μ sandan α -decay branching ratio of 4 ± 2% was determined. Improved half-life and branching ratio measurements were also obtained for 165 Ir, but no evidence was found for the ground-state decays of either 164 Ir or 1…
Acidity and basicity of primaryN-phenylnitramines: catalytic effect of protons on the nitramine rearrangement
2002
Para-substituted N-phenylnitramines were prepared either by oxidation of diazonium salts or by nitration under alkaline or acidic conditions. Isotopic [15N-NO2] labelling indicated that the bands characteristic of the N-nitro group appear in the 1318–1323 and 1585–1607 cm−1 regions. In the nitrogen NMR spectra, the nitramino group gives two resonances at −193 ± 3 (NH) and −32 ± 3 ppm (NO2). The chemical shifts in proton and carbon NMR spectra are predictable, based on increments and the additivity rule. The spectral data indicate the lack of conjugation between the nitramino group and another substituent bound to the ring. It seems to contradict the well-known fact that substituents strongl…
Inference of proto-neutron star properties from gravitational-wave data in core-collapse supernovae
2021
The eventual detection of gravitational waves from core-collapse supernovae (CCSN) will help improve our current understanding of the explosion mechanism of massive stars. The stochastic nature of the late post-bounce gravitational wave signal due to the non-linear dynamics of the matter involved and the large number of degrees of freedom of the phenomenon make the source parameter inference problem very challenging. In this paper we take a step towards that goal and present a parameter estimation approach which is based on the gravitational waves associated with oscillations of proto-neutron stars (PNS). Numerical simulations of CCSN have shown that buoyancy-driven g-modes are responsible …
Direct Visualization of Molecule Deprotonation on an Insulating Surface
2012
Elucidating molecular-scale details of basic reaction steps on surfaces is decisive for a fundamental understanding of molecular reactivity within many fields, including catalysis and on-surface synthesis. Here, the deprotonation of 2,5-dihydroxybenzoic acid (DHBA) deposited onto calcite (101;4) held at room temperature is followed in situ by noncontact atomic force microscopy. After deposition, the molecules form two coexisting phases, a transient striped phase and a stable dense phase. A detailed analysis of high-resolution noncontact atomic force microscopy images indicates the transient striped phase being a bulk-like phase, which requires hydrogen bonds between the carboxylic acid moie…
The beta-delayed proton and gamma decay of 27P for nuclear astrophysics
2013
The creation site of 26Al is still under debate. It is thought to be produced in hydrogen burning and in explosive helium burning in novae and supernovae, and possibly also in the H-burning in outer shells of red giant stars. Also, the reactions for its creation or destruction are not completely known. When 26Al is created in novae, the reaction chain is: 24Mg(p, γ) 25Al(β +ν) 25Mg(p, γ) 26Al, but this chain can be by-passed by another chain, 25Al(p, γ) 26Si(p, γ) 27P and it can also be destroyed directly. The reaction 26mAl(p, γ) 27Si∗ is another avenue to bypass the production of 26Al and it is dominated by resonant capture. We find and study these resonances by an indirect method, throug…
Proton Exchange Membrane Fuel Cells (PEMFCs): Advances and Challenges
2021
The study of the electrochemical catalyst conversion of renewable electricity and carbon oxides into chemical fuels attracts a great deal of attention by different researchers. The main role of this process is in mitigating the worldwide energy crisis through a closed technological carbon cycle, where chemical fuels, such as hydrogen, are stored and reconverted to electricity via electrochemical reaction processes in fuel cells. The scientific community focuses its efforts on the development of high-performance polymeric membranes together with nanomaterials with high catalytic activity and stability in order to reduce the platinum group metal applied as a cathode to build stacks of proton …
"Table 1" of "Jet-like correlations with neutral pion triggers in pp and central Pb-Pb collisions at 2.76 TeV"
2016
Charged-particle associated yields relative to $\pi^{0}$ trigger particles versus $\Delta\varphi$ in pp collisions at $\sqrt{s_{NN}}$=2.76 TeV. The $\pi^{0}$ trigger momentum range is $8< p_{T}^{trig} < 16~GeV/c$, and associated charged particle ranges are $0.5 < p_{T}^{assoc} < 1$, $1 < p_{T}^{assoc} < 2$, $2 < p_{T}^{assoc} < 4$ and $4 < p_{T}^{assoc} < 6~GeV/c$.
"Table 2" of "Search for Higgs boson decays into a $Z$ boson and a light hadronically decaying resonance using 13 TeV $pp$ collision data from the AT…
2020
Efficiencies of the MLP selection, complete selection and total expected signal yields for each signal sample, assuming B$(H\to Z(Q/a))=100\%$ and $\sigma(pp\to H) = \sigma_\text{SM}(pp\to H)$. Pythia 8 branching fractions of $a$ are assumed using a $\tan\beta$ value of 1. The MLP efficiencies, total efficiencies, and expected yields are determined using MC samples, with uncertainties due to MC sample statistics, except for the expected background yield. The expected background yield and its uncertainty is calculated as described in the main text of the paper.
"Table 1" of "Search for Higgs boson decays into a $Z$ boson and a light hadronically decaying resonance using 13 TeV $pp$ collision data from the AT…
2020
Observed number of data events and expected number of background events in the signal region.
The PANDA Endcap Disc DIRC
2018
Journal of Instrumentation 13(02), C02002 - C02002 (2018). doi:10.1088/1748-0221/13/02/C02002