This article describes calculations of the yield ratio of anti-particles to the yield of particles (
/
p
,
/
d
,
/
3
He) in proton–proton and nuclear–nuclear interactions using the self-similarity ...parameter in the central rapidity region. The used approach is based on the study of relativistic nuclear interactions in the four-velocity space. The results of the calculations are compared with the existing experimental data in a wide center-of-mass energy range (
SPS
,
RHIC
,
LHC
). Within this approach the inclusive spectra of pions and kaons and ratios of their yields in pp collisions have been successfully described earlier.
Abstract
Visual analysis allows an estimate of different local boiling characteristics including bubble growth rate, departure diameters and frequencies of nucleation, nucleation site density and ...evolution of bubbles and dry spots in time. At the same time, visual determination of the presented characteristics in case of big amounts of data requires the development of the appropriate software which will allow not only determination of bubble location, but also an estimate of their sizes based on high-speed video. The presented problem can be solved by using the instance segmentation approach based on a convolutional neural network. In the presented work Mask R-CNN network architecture was used for estimation of the local boiling characteristics.
In this paper the results of comprehensive study on the multiscale characteristics and heat transfer rate during water boiling in the pressure range from 8.8 to 103 kPa are presented. The ...experimental data are obtained using the modern experimental techniques, including high-speed video recording and infrared thermography. The usage of the special design of a transparent heating surface allows gaining a full set of major multiscale pool boiling characteristics. In particular, new data have been revealed on the vapor bubble growth rate and departure diameter, bubble emission frequency and nucleation site density during pool boiling in vacuum. The simple expression to predict the effect of pressure reduction on nucleation site density value is also presented.
We used piston cores recovered in the western Bering Sea to reconstruct millennial-scale changes in marine productivity and terrigenous matter supply over the past ~180 kyr. Based on a geochemical ...multi-proxy approach, our results indicate closely interacting processes controlling marine productivity and terrigenous matter supply comparable to the situation in the Okhotsk Sea. Overall, terrigenous inputs were high, whereas export production was low. Minor increases in marine productivity occurred during intervals of Marine Isotope Stage 5 and interstadials, but pronounced maxima were recorded during interglacials and Termination I. The terrigenous material is suggested to be derived from continental sources on the eastern Bering Sea shelf and to be subsequently transported via sea ice, which is likely to drive changes in surface productivity, terrigenous inputs, and upper-ocean stratification. From our results we propose glacial, deglacial, and interglacial scenarios for environmental change in the Bering Sea. These changes seem to be primarily controlled by insolation and sea-level forcing which affect the strength of atmospheric pressure systems and sea-ice growth. The opening history of the Bering Strait is considered to have had an additional impact. High-resolution core logging data (color b*, XRF scans) strongly correspond to the Dansgaard-Oeschger climate variability registered in the NGRIP ice core and support an atmospheric coupling mechanism of Northern Hemisphere climates.
A series of new styryl type thiacarbocyanine dyes containing iodine atoms in the donor and/or acceptor moiety have been synthesized, and their electronic absorption spectra in the regions of ...singlet–singlet (
S
0
–
S
1
) and singlet–triplet (
S
0
–
T
1
) transitions have been studied. Introduction of iodine atoms into the dye molecules leads to a red shift of the absorption maximum, regardless of the iodine position. The electronic absorption spectra of dyes containing two and more iodine atoms showed a weak shoulder in the range from λ 650 to 1000 nm, which corresponds to the singlet–triplet transition.
Abstract
In this paper, the results of numerical calculations of a vapor bubble growth in superheated water at different pressures are presented. Modeling is based on a previously developed by the ...authors semi-analytical solution. The results are verified by experimental data obtained at atmospheric and subatmospheric pressures. The presented simulation results and experimental data are in good agreement. The advantage of the solution over the earlier ones (based on the thermal growth model) is shown.
The effect of surface wettability and pressure on multiscale heat transfer characteristics at liquid boiling was studied. The experiments were carried out at saturated water boiling on surfaces with ...different wettability in the pressure range of 8.8–103 kPa. The usage of transparent ITO film heater deposited on a sapphire substrate and high-speed visualization showed the nucleation site density to reduce with decreasing pressure and to significantly increase on heaters with hydrophobic fluoropolymer coatings. The results on the vapor bubble growth rate, bubble emission frequency, and evolution of the triple contact line at spreading of dry spots are also analyzed in detail. In particular, the rate of dry spot growth on a hydrophilic surface was shown to have a non-monotonic dependence with the lower extremum at pressures in the range of 22–42 kPa depending on the heat flux. The usage of high-speed infrared thermography enabled measurement of the temperature field of the heating surface and determination of the heat transfer rate at boiling depending on the pressure and surface wettability. The heat transfer was shown to decrease with the pressure at boiling on hydrophilic heaters, whereas it can be significantly enhanced due to a hydrophobic coating at atmospheric pressure in the range of low heat fluxes.
The paper is concerned with an experimental study of heat transfer and boiling crisis development on a biphilic silicon surface made using a set of methods, including chemical vapor deposition and ...laser texturing. It is shown that the use of a biphilic surface with the proposed configuration of hydrophobic zones on a superhydrophilic base leads simultaneously to an increase in heat transfer by 60% and an increase in the critical heat flux by 76% as compared to an unmodified surface.
The paper presents the results of calculations of the parameters of contact interaction of the wheels of a freight car with R65 rails (wheel wear rate, areas of wheel contact spots with rails, ...friction power capacities in contact spots) for various operating conditions on the Russian Railways road network. The choice of groups of operating conditions was made on the basis of the methodology for ranking the characteristics of the main roads in the plan and profile. The quantitative values of the parameters of contact interaction were established, and their comparative analysis was carried out for the conditions under consideration.
The article presents theoretical principles of the methods and devices for water activity (aw) measurement. The purpose of the research is the increase of the validity of water activity indicator ...measurement on the basis of a direct method of material test; the optimization of the structure of an automated measuring device to provide the possibilities for a simultaneous study of several samples (for example, food materials) with various water activity levels. A developed measuring device allows a simultaneous determination of indicators in several samples (8) located circumferentially and includes thermal sensors. The sensors in this device are represented by induction coils. They are installed on both leg pipes (made of nonmagnet materials) of a liquid level manometer. The device contains a special silicon organic oil with the pressure of partial steams within 10-6 Pa (at normal conditions) used as a manometric liquid. While measuring the device is vacuumized and thermostated. The method and device approbation resulted in making calibration charts at various temperatures, approximated with the help of software. The device provides the validity of measurements in water activity range from 0.45 to 1.0.
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