Recently, multiparticle-correlation measurements of relativistic p/d/^{3}He+Au, p+Pb, and even p+p collisions show surprising collective signatures. Here, we present beam-energy-scan measurements of ...two-, four-, and six-particle angular correlations in d+Au collisions at sqrts_{NN}=200, 62.4, 39, and 19.6 GeV. We also present measurements of two- and four-particle angular correlations in p+Au collisions at sqrts_{NN}=200 GeV. We find the four-particle cumulant to be real valued for d+Au collisions at all four energies. We also find that the four-particle cumulant in p+Au has the opposite sign as that in d+Au. Further, we find that the six-particle cumulant agrees with the four-particle cumulant in d+Au collisions at 200 GeV, indicating that nonflow effects are subdominant. These observations provide strong evidence that the correlations originate from the initial geometric configuration, which is then translated into the momentum distribution for all particles, commonly referred to as collectivity.
An analytical study of the problem of water infiltration into a homogeneous unsaturated soil showed that, in the case of periodical water recharge through the soil surface, the character of the flow ...will tend to uniform with the depth. The stabilization of the flow was found to be due to the effect of two factors: capillary dissipation and nonlinearity. The role of each factor was studied by constructing appropriate exact solutions. An estimate was proposed for the depth at which flow variations become insignificant. This estimate takes into account the joint effect of both these factors. An explicit expression for it contains the hydraulic characteristics of the soil and the main characteristics of the surface recharge regime. The pumping effect was also studied and it was showed that, at some assumptions regarding the soil hydraulic characteristics, it manifests itself in that the time-averaged water content in the top soil layers is less than that at greater depth.
The environmental effect of landfills of solid municipal wastes is considered, including their effect on groundwater. The accumulation of municipal wastes causes considerable changes in the physical, ...chemical, and biological properties of groundwater. Leachates containing toxicants of all hazard classes reach water intakes. The effect of dumps can be minimized by the ecologically sound choice of the sites for new dumps and by monitoring the dumps now in use. The groundwater of developed aquifers, as well as the functioning and abandoned waste dumps, which are still polluting the environment, require monitoring over space and time.
More than 31 billion tons of unutilized waste have accumulated in Russia, and this amount is increasing every year. The dump sites’ locations require profound scientific analysis. When choosing areas ...for landfill sites with minimal environmental damage to surrounding areas, it is necessary to consider the following aspects: the degree of suitability of natural conditions, the engineering and geological features of the territories, including the lithological, soil, hydrological and hydrogeological, geofiltration conditions of territories, as well as the presence of settlements and sanitary zones around them, etc. At present, the choice of sites for landfills is carried out without engineering and geological surveys, without taking into account the presence of geochemical barriers and the depth to groundwater. The negative impact on the environment of MSW landfills, the design of which was carried out without taking into account the geological structure and hydrogeological conditions of the territories where they were located, was considered.
Mathematical modeling was used to identify zones with different magnitudes of the barrage effect on the construction of buildings with deep-laid foundation in the Moscow region. Assessment of the ...barrage effect should take into account not only the magnitude of the groundwater flow but its level position relative to the earth’s surface. If the groundwater level (GWL) is located at a considerable depth, even deep-laid foundations of a building under construction and, accordingly, a substantial rise in groundwater table will not result in a critical situation whereby the foundations of neighboring buildings are submerged and the bearing capacity of the soil under the foundations is changed. Analysis of the geological data and the calculations that were carried out made it possible to establish the distribution of barrage effect values in Moscow.
During 2015, the Relativistic Heavy Ion Collider (RHIC) provided collisions of transversely polarized protons with Au and Al nuclei for the first time, enabling the exploration of ...transverse-single-spin asymmetries with heavy nuclei. Large single-spin asymmetries in very forward neutron production have been previously observed in transversely polarized p+p collisions at RHIC, and the existing theoretical framework that was successful in describing the single-spin asymmetry in p+p collisions predicts only a moderate atomic-mass-number (A) dependence. In contrast, the asymmetries observed at RHIC in p+A collisions showed a surprisingly strong A dependence in inclusive forward neutron production. The observed asymmetry in p+Al collisions is much smaller, while the asymmetry in p+Au collisions is a factor of 3 larger in absolute value and of opposite sign. The interplay of different neutron production mechanisms is discussed as a possible explanation of the observed A dependence.
The problem of steady-state free surface ground water flow through a porous medium is represented in the form of a variational principle for a functional dependent on the flow domain. It is proved ...that on the region to be found this functional takes a minimum value. This variational principle is generalized to include the flow models that allow the presence of partially saturated zones in the medium. On simple examples it is shown how the variational formulation can be used for proving the existence or absence of solutions.
The PHENIX Electromagnetic Calorimeter (EMCal) is used to measure the spatial position and energy of electrons and photons produced in heavy ion collisions. It covers the full central spectrometer ...acceptance of 70°⩽
θ⩽110° with two walls, each subtending 90° in azimuth. One wall comprises four sectors of a Pb-scintillator sampling calorimeter and the other has two sectors of Pb-scintillator and two of a Pb-glass Cherenkov calorimeter. Both detectors have very good energy, spatial and timing resolution, while the Pb-scintillator excels in timing and the Pb-glass in energy measurements. Also, having two detectors with different systematics increases the confidence level of the physics results. Design and operational parameters of the Pb-scintillator, Pb-glass and special readout electronics for EMCal are presented and running experience during the first year of data taking with PHENIX is discussed. Some examples of data taken during the first run are shown.
An analytical study of the problem of water infiltration into a homogeneous unsaturated soil showed that, in the case of periodical water recharge through the soil surface, the character of the flow ...will tend to uniform with the depth. The stabilization of the flow was found to be due to the effect of two factors: capillary dissipation and nonlinearity. The role of each factor was studied by constructing appropriate exact solutions. An estimate was proposed for the depth at which flow variations become insignificant. This estimate takes into account the joint effect of both these factors. An explicit expression for it contains the hydraulic characteristics of the soil and the main characteristics of the surface recharge regime. The pumping effect was also studied and it was showed that, at some assumptions regarding the soil hydraulic characteristics, it manifests itself in that the time-averaged water content in the top soil layers is less than that at greater depth.
Experimental studies of the collisions of heavy nuclei at relativistic energies have established the properties of the quark–gluon plasma (QGP), a state of hot, dense nuclear matter in which quarks ...and gluons are not bound into hadrons1–4. In this state, matter behaves as a nearly inviscid fluid5 that efficiently translates initial spatial anisotropies into correlated momentum anisotropies among the particles produced, creating a common velocity field pattern known as collective flow. In recent years, comparable momentum anisotropies have been measured in small-system proton–proton (p+p) and proton–nucleus (p+A) collisions, despite expectations that the volume and lifetime of the medium produced would be too small to form a QGP. Here we report on the observation of elliptic and triangular flow patterns of charged particles produced in proton–gold (p+Au), deuteron–gold (d+Au) and helium–gold (3He+Au) collisions at a nucleon–nucleon centre-of-mass energy \\sqrt {s_{{\mathrm{NN}}}\ = 200 GeV. The unique combination of three distinct initial geometries and two flow patterns provides unprecedented model discrimination. Hydrodynamical models, which include the formation of a short-lived QGP droplet, provide the best simultaneous description of these measurements.
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