Обоснование параметров усовершенствованного сошника для внесения минеральных и органо-минеральных удобрений

When using the conventional coulters for applying organic-and-mineral fertilizers, reliable technological process cannot be ensured unless a fertilizer funnel is adapted to such fertilizers. (Research purpose) Determination of the parameters of an improved coulter for introducing organic-and-mineral fertilizers. (Materials and methods) The authors conducted theoretical studies using the methods of theoretical and agricultural mechanics, as well as analytic geometry. They also considered the horizontal flow of soil particles under the action of the pointed part of a leg and made diagrams of the progressive speed of a cultivator depending on the cutting-point angle of the coulter leg at friction angles of 25, 30, and 35 degrees. (Results and discussion) An analytical relationship was obtained to determine progressive flowability of organic-and-mineral fertilizers through a coulter funnel. The author also found the cutting-point angle of a coulter leg for introducing fertilizers at a certain depth. In this case they neither stick to the coulter surface nor pack up before entering it. The optimum diameter of the fertilizer funnel was determined as well. (Conclusions) It has been proved that the cutting-point angle of a working tool leg for introducing mineral and organic-and-mineral fertilizers developed according to the research should range from 54 to 66 degrees. The authors have determined that an easy flow of fertilizers can be ensured if the diameter of a fertilizer funnel of a coulter should be not less than 43 millimeters.При использовании существующих сошников для внесения органо-минеральных удобрений не обеспечивается надежное протекание технологического процесса, так как шейка тукопровода не приспособлена к внесению таких удобрений. (Цель исследований) Обосновать параметры усовершенствованного сошника для внесения минеральных и органо-минеральных удобрений. (Материалы и методы) Провели исследования с использованием методов теоретической и земледельческой механики, а также аналитической геометрии. Рассмотрели движение частиц почвы по горизонтальной плоскости под действием заостренной части стойки. Построили графики изменения поступательной скорости культиватора в зависимости от угла заострения стойки сошника при углах трения 25, 30 и 35 градусов. (Результаты и обсуждение) Получили аналитическую зависимость для определения поступательной способности органо-минеральных удобрении через шейку сошника. Определили угол заострения стойки сошника для внесения удобрений на определенную глубину, при котором они не прилипают к его поверхности и не сгруживаются перед ним. Обосновали диаметр шейки тукопровода сошника. (Выводы) Доказали, что угол заострения стойки рабочего органа для внесения минеральных и органо-минеральных удобрений, разработанного по результатам проведенных исследований, должен быть в пределах 54-66 градусов. Рекомендовали для обеспечения свободного прохода удобрений диаметр шейки тукопровода сошника, превышающий 43 миллиметра

Reeconstructing Sigma0 decays in STAR

Typical comparisons of data from nuclear collisions to particle production models require a caveat for (anti)Lambda yields from experimental inability to separate the contributions of those yields from Sigma state decays. Recent analysis in STAR is leading toward resolving the contribution from excited Sigma states, but the bulk contribution comes from electromagnetic decays of the (anti)Sigma0. In the STAR detector, photon conversions into e+e- pairs in the detector material have been used to identify photons from pi0 decays. A similar technique has been used here to identify photons from (anti)Sigma0 decays in conjunction with STAR's excellent PID capabilities for finding the associated (anti)Lambda daughters. We report here on progress toward measuring the (anti)Sigma0 yields in various nuclear collisions at RHIC.Comment: 8 pages, 5 figures, proceedings of Hot Quarks 2004 workshop, submitted to J. Phys.

Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal

A study of backward going pp and π−\pi^{-} in νμCC\nu_{\mu}CC interactions with the NOMAD detector

Backward proton and $\pi^-$ production has been studied in $\nu_{\mu}CC$ interactions with carbon nuclei. Detailed analyses of the momentum distributions, of the production rates, and of the general features of events with a backward going particle, have been carried out in order to understand the mechanism producing these particles. The backward proton data have been compared with the predictions of the reinteraction and the short range correlation models.Comment: 29 pages, 14 figures, submitted to Nucl. Phys.

The BM@N spectrometer at the NICA accelerator complex

BM@N (Baryonic Matter at Nuclotron) is the first experiment operating and taking data at the Nuclotron/NICA ion-accelerating complex.The aim of the BM@N experiment is to study interactions of relativistic heavy-ion beams with fixed targets. We present a technical description of the BM@N spectrometer including all its subsystems.Comment: 34 pages, 47 figures, 6 table

Inclusive and differential cross section measurements of single top quark production in association with a Z boson in proton-proton collisions at √s = 13 TeV

Inclusive and differential cross sections of single top quark production in association with a Z boson are measured in proton-proton collisions at a center-of-mass energy of 13 TeV with a data sample corresponding to an integrated luminosity of 138 fb−1 recorded by the CMS experiment. Events are selected based on the presence of three leptons, electrons or muons, associated with leptonic Z boson and top quark decays. The measurement yields an inclusive cross section of 87.9−7.3+7.5(stat)−6.0+7.3(syst) fb for a dilepton invariant mass greater than 30 GeV, in agreement with standard model (SM) calculations and represents the most precise determination to date. The ratio between the cross sections for the top quark and the top antiquark production in association with a Z boson is measured as 2.37−0.42+0.56(stat)−0.13+0.27(syst). Differential measurements at parton and particle levels are performed for the first time. Several kinematic observables are considered to study the modeling of the process. Results are compared to theoretical predictions with different assumptions on the source of the initial-state b quark and found to be in agreement, within the uncertainties. Additionally, the spin asymmetry, which is sensitive to the top quark polarization, is determined from the differential distribution of the polarization angle at parton level to be 0.54 ± 0.16 (stat) ± 0.06 (syst), in agreement with SM predictions. [Figure not available: see fulltext.

MUSiC: a model-unspecific search for new physics in proton–proton collisions at √s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton–proton collision data recorded at the LHC at a centre-of-mass energy of 13TeV, corresponding to an integrated luminosity of 35.9fb-1, are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches

Search for a right-handed W boson and a heavy neutrino in proton-proton collisions at s \sqrt{s} = 13 TeV

A search is presented for a right-handed W boson (WR) and a heavy neutrino (N), in a final state consisting of two same-flavor leptons (ee or μμ) and two quarks. The search is performed with the CMS experiment at the CERN LHC using a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 138 fb−1. The search covers two regions of phase space, one where the decay products of the heavy neutrino are merged into a single large-area jet, and one where the decay products are well separated. The expected signal is characterized by an excess in the invariant mass distribution of the final-state objects. No significant excess over the standard model background expectations is observed. The observations are interpreted as upper limits on the product of WR production cross sections and branching fractions assuming that couplings are identical to those of the standard model W boson. For N masses mN equal to half the WR mass mWR (mN = 0.2 TeV), mWR is excluded at 95% confidence level up to 4.7 (4.8) and 5.0 (5.4) TeV for the electron and muon channels, respectively. This analysis provides the most stringent limits on the WR mass to date