76 research outputs found
Two Particle Azimuthal Correlations in 4.2A GeV C+Ta Collisions
Two particle azimuthal correlations are studied in 4.2A GeV C+Ta collisions
observed with the 2-m propane bubble chamber exposed at JINR Dubna
Synchrophasotron. The correlations are analyzed both for protons and negative
pions, and their dependence on the collision centrality, rapidity and rapidity
difference is investigated. It is found that protons show a weak back-to-back
correlations, while a side-by-side correlations are observed for negative
pions. Restricting both protons to the target or projectile fragmentation
region, the side-by-side correlations are observed for protons also. Using the
two particle correlation function, the flow analysis is performed and intensity
of directed flow is determined without event-by event estimation of the
reaction plane.Comment: 4 pages, 3 figure
Intermetallics – advanced cathode materials in the electrolytic production of hydrogen
The intermetallics, Ti–Pt, Nb-Pd (80%Nb), Pd-Ta, Nb-Pd (65% Nb), Zr-Pt, Hf2Fe and PtMo3, of transition metals have been investigated as cathode materials for the electrolytic hydrogen evolution in an attempt to increase the electrolytic process efficiency. These materials were compared with conventional cathode, Ni. An significant upgrade of the electrolytic efficiency using intermetallics was achived. The effects of those cathode materials on the process efficiency were discussed in the context of transition metal features that issue from their d-electronic configuration.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200
Anisotropic flow in 4.2A GeV/c C+Ta collisions
Anisotropic flow of protons and negative pions in 4.2A GeV/c C+Ta collisions
is studied using the Fourier analysis of azimuthal distributions. The protons
exhibit pronounced directed flow. Directed flow of pions is positive in the
entire rapidity interval and indicates that the pions are preferentially
emitted in the reaction plane from the target to the projectile. The elliptic
flow of protons and negative pions is close to zero. Comparison with the
quark-gluon-string model (QGSM) and relativistic transport model (ART 1.0) show
that they both yield a flow signature similar to the experimental data.Comment: 4 pages, 3 figures, Accepted for publication in Phys. Rev.
Energy consumption in the electrolytic evolution of hydrogen with iron-nickel electrodes
The possibilities to reduce energy consumption in the electrolytic hydrogen production using ionic activators added into an alkaline electrolyte have been investigated. Two cathode/anode systems, Fe/Ni and Ni/Fe were investigated. We have found that some activators, like tris-(ethylenediamine)Co(III) chloride complex in combination with the sodium molybdate can reduce energy needs per mass unit of hydrogen produced for more than ten percent in all investigated systems compared to those of non-activated electrolytes. Additionally, iron exhibits some special properties in this view.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200
Proton stopping in C+C, d+C, C+Ta and d+Ta collisions at 4.2A GeV/c
The shape of proton rapidity distributions is analysed in terms of their
Gaussian components, and the average rapidity loss is determined in order to
estimate the amount of stopping in C+C, d+C, C+Ta and d+Ta collisions at 4.2A
GeV/c. Three Gaussians correspond to the nuclear transparency and describe well
all peripheral and also C+C central collisions. Two-component shape is obtained
in case of d+C and C+Ta central collisions. Finally one Gaussian, found in d+Ta
central collisions, corresponds to the full stopping. The calculated values of
the average rapidity loss support the qualitative relationship between the
number of Gaussian components and the corresponding stopping power. It is also
observed, in central collisions, that the average rapidity loss increases with
the ratio of the number of target and the number of projectile participants.Comment: 9 pages REVTeX, 1 PS figure replaced, to be published in Phys.Rev.
Effect of soybean/proso millet intercropping combined with bio-fertilizer on accumulation of essential elements in grain
Intercropping, as sustainable agricultural practice effectively uses environmental resources,
affecting the nutritive quality of crops by modifying the concentration of macro- and microelements
in grain. In order to improve the availability of nutrients from the soil, bio-fertilizers could
also be used successfully in elements management. A field experiment was conducted with soybean (var. Selena) and proso millet (var. Biserka) to examine the integrated influence of intercropping and bio-fertilizer on Ca, Mg, S, Fe and Zn accumulation in grain. Mono-crops (T1 - soybean, T2 - millet), as well as tree planting patterns of intercrop, including alternating rows of soybean and proso millet (T3), alternating strips of two rows of soybean and two rows of millet (T4) and alternating strips of two rows of soybean and four rows of millet (T5), were set up in 2018 and
2020. The same combinations, as subplots, were treated with bio-fertilizer Coveron (C) (containing
mycorrhizal fungi, Trichoderma and plant growth-promoting rhizobacteria). After harvest, grains
were dried and milled and preparation of samples was performed using wet digestion procedure
with HClO4 + HNO3. The concentration of Ca, Mg and S were determined by ICP-OES, while Fe
and Zn concentration was measured on ICP-MS. Results showed that Coveron reduced S
concentration in soybean grain, while the status of other elements mainly remained unchanged. In
terms of intercropping, soybean from T5 combination had a significantly higher level of Fe in
comparison to T1 and T3, and higher but not significantly than T4, emphasizing alternating strips as
more effective for accumulation of this element in grain. Combination T3 + C provided the highest
accumulation of Ca, while T5 + C significantly raised Fe concentration. In terms of proso millet,
bio-fertilizer expressed a greater impact on Ca, Fe and Zn by increasing their concentration. On the
other side, all intercrop combinations expressed a positive impact on Fe concentration and
simultaneously reduced Zn concentration. When mutual influence is considered, T4 + C
significantly increased Ca and Fe values, while T2 + C increased Zn value, pointing positive effect
of integrated and sustainable agricultural practices on an accumulation of essential elements in a
grain of proso millet. In conclusion, different intercrop combinations combined with bio-fertilizer
could be successfully used to improve the nutritional quality of soybean and millet grains in terms
of sustainable food production, but further investigations are required to highlight other aspects of
potentially enhanced nutritional quality
Search for W - GT t(b)over-bar in the lepton plus jets final state in proton-proton collisions at a centre-of-mass energy of root s=8 TeV with the ATLAS detector
A search for new charged massive gauge bosons, called W, is performed with the ATLAS detector at the LHC, in proton-proton collisions at a centre-of-mass energy of root s = 8 TeV, using a dataset corresponding to an integrated luminosity of 20.3 fb(-1). This analysis searches for W bosons in the W - GT t (b) over tilde decay channel in final states with electrons or muons, using a multivariate method based on boosted decision trees. The search covers masses between 0.5 and 3.0 TeV, for right-handed or left-handed W bosons. No significant deviation from the Standard Model expectation is observed and limits are set on the W - GT t (b) over bar cross-section times branching ratio and on the W-boson effective couplings as a function of the W-boson mass using the CLs procedure. For a left-handed (right-handed) W boson, masses below 1.70 (1.92) TeV are excluded at 95% confidence level. Published by Elsevier B.V
Search for dark matter in events with heavy quarks and missing transverse momentum in pp collisions with the ATLAS detector
This article reports on a search for dark matter pair production in association with bottom or top quarks in 20.3 fb(-1) of pp collisions collected at root s = 8 TeV by the ATLAS detector at the LHC. Events with large missing transverse momentum are selected when produced in association with high-momentum jets of which one or more are identified as jets containing b-quarks. Final states with top quarks are selected by requiring a high jet multiplicity and in some cases a single lepton. The data are found to be consistent with the Standard Model expectations and limits are set on the mass scale of effective field theories that describe scalar and tensor interactions between dark matter and Standard Model particles. Limits on the dark-matter-nucleon cross-section for spin-independent and spin-dependent interactions are also provided. These limits are particularly strong for low-mass dark matter. Using a simplified model, constraints are set on the mass of dark matter and of a coloured mediator suitable to explain a possible signal of annihilating dark matter
Search for new phenomena in events with a photon and missing transverse momentum in pp collisions at root s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in events with an energetic photon and large missing transverse momentum with the ATLAS experiment at the LHC are reported. Data were collected in proton-proton collisions at a center-of-mass energy of 8 TeVand correspond to an integrated luminosity of 20.3 fb(-1). The observed data are well described by the expected Standard Model backgrounds. The expected (observed) upper limit on the fiducial cross section for the production of events with a photon and large missing transverse momentum is 6.1 (5.3) fb at 95% confidence level. Exclusion limits are presented on models of new phenomena with large extra spatial dimensions, supersymmetric quarks, and direct pair production of dark-matter candidates
Standalone vertex finding in the ATLAS muon spectrometer
A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to b (b) over bar final states, and pp collision data at root s = 7 TeV collected with the ATLAS detector at the LHC during 2011
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