Estimation of Bed Expansion and Separation Density of Gas–Solid Separation Fluidized Beds Using a Micron-Sized-Particle-Dense Medium

Coal is the dominant energy resource in China. With the Chinese policy of committing to reducing peak carbon dioxide emissions and achieving carbon neutrality, coal separation has recently become a hot topic, especially the fluidized separation of fine particles. In this study, micron-sized particles were introduced to ameliorate the properties of the traditional fluidized bed. The expansion characteristics of the micron-sized-particle-dense medium were explored. A bed expansion prediction model of the micron-sized-particle-dense medium was established, and the prediction error was about 10%, providing a theoretical basis for understanding the distribution characteristics of the bed. This model also helped predict the bed density in the presence of a micron-sized-particle-dense medium, and the prediction accuracy was between 85% and 92%, providing a theoretical basis for selecting and popularizing fluidized beds for industrial separation.

SOFIA Observations of 30 Doradus. I. Far-infrared Dust Polarization and Implications for Grain Alignment and Disruption by Radiative Torques

Located in the Large Magellanic Cloud and mostly irradiated by the massive star cluster R136, 30 Doradus is an ideal target to test the leading theory of grain alignment and rotational disruption by RAdiative Torques (RATs). Here, we use publicly available polarized thermal dust emission observations of 30 Doradus at 89, 154, and 214 μm using SOFIA/HAWC+. We analyze the variation of the dust polarization degree (p) with the total emission intensity (I), the dust temperature (T d), and the gas column density (N H) constructed from Herschel data. The 30 Doradus complex is divided into two main regions relative to R136, namely North and South. In the North, we find that the polarization degree first decreases and then increases before decreasing again when the dust temperature increases toward the irradiating cluster R136. The first depolarization likely arises from the decrease in grain alignment efficiency toward the dense medium due to the attenuation of the interstellar radiation field and the increase in the gas density. The second trend (the increase of p with T d) is consistent with the RAT alignment theory. The final trend (the decrease of p with T d) is consistent with the RAT alignment theory only when the grain rotational disruption by RATs is taken into account. In the South, we find that the polarization degree is nearly independent of the dust temperature, while the grain alignment efficiency is higher around the peak of the gas column density and decreases toward the radiation source. The latter feature is also consistent with the prediction of rotational disruption by RATs.

High-yielding cultivar of spring turnip rapeseed of “000” type Gratsiya

The spring turnip rapeseed cultivar Gratsiya was developed at the Siberian experimental station – a branch of V.S. Pustovoit All-Russian Research Institute of Oil Crops by multiple individual and family selections from high-yielding, yellowseeded forms of the German cultivar Eldorado. In 2020, we isolated elite plant in the selection nursery by the main agronomic valuable traits: early maturity, high productivity, resistance to lodging, yellow seed color, low content of glucosinolates in the seeds and erucic acid in the oil. According to the results of three years competitive trials (2018–2020), 12 promising numbers with a growing season of 66–70 days were evaluated and a promising high-yielding number 31119 – the cultivar of type “000” Gratsiya was isolated. The cultivar of spring turnip rapeseed Gratsiya exceeded the standard cultivar Pobeda in seed yield by 0.21 t/ha and in oil yield by 0.08 t/ha. By the main agronomic traits, the cultivar Gratsiya differs from the standard one in lower content of glucosinolates in seeds (14.6 µmol/g) and erucic acid in oil (0.43 %). Seedlings are green, without wax coating, the plant is semi-dense, medium-branched, plant height of 120– 135 cm. The fruit is a pod, 5–7 cm long. Seeds are yellow, with an addition of brown – up to 2 %. Thousand-seed weight is 2.5–2.8 g. It is moderately drought-resistant, has uniform ripening, is suitable for mechanical harvesting, and is recommended for cultivation throughout the Russian Federation because of its early maturity.

Green open space analysis in West Binjai, North Sumatra

West Binjai is a sub-district located in Binjai City, North Sumatra. Green Open Space is also part of the Binjai city’s planning scheme which has many benefits for the community and the environment. This research used Normalized Difference Vegetation Index (NDVI) analysis and NDVI value classification results in the distribution of vegetation density. Analysis of changes in vegetation density was carried out between 2015 and 2020 in West Binjai. The largest change in the area of vegetation density classes in the West Binjai between 2015 and 2020 was the increase in the area of the high dense class to 19.13%. The sub-district has green open spaces in the form of sub-district parks, public cemeteries, road green lane, river bank and private green open spaces. These green open spaces were in the low dense, medium, dense and high dense classes. There is a need for rearrangement of green open spaces, especially those within low dense class. Replanting trees are also essential to increase the quality of the green area. Improving the quality of green space will lead to the enhancement of quality of environment.

Properties of ρ(770)0, K*(892), ϕ(1020), ∑(1385)±, Λ(1520) and Ξ(1530)0 resonances in heavy-ion collisions at a center of mass energy of SNN=4-11GeV and their reconstruction using the MPD detector at NICA

The short-lived hadronic resonances are used to study properties of the hot and dense medium produced in relativistic heavy-ion collisions. Due to their short lifetimes, the resonance yields and masses measured in the hadronic channels are sensitive to rescattering and regeneration effects in the hadronic phase. The measurement of resonances is foreseen in the physical program of the MPD experiment at NICA in heavy-ion collisions at S N N = 4 - 11 GeV , in the range of energies where extensive measurements of resonances are not experimentally available. In this contribution, we explore the sensitivity of the ρ(770)0, K*(892), ϕ(1020), ∑(1385)±, Λ(1520) and Ξ(1530)0 resonances measured in the hadronic decay channels to different stages of the heavy-ion collisions at NICA energies and report the feasibility studies for the reconstruction of resonances in the MPD setup

Transport Model Approach to Λ and Λ¯ Polarization in Heavy-Ion Collisions

This paper investigates the symmetry breaking between the polarizations of Λ and Λ¯ hyperons in relativistic collisions of heavy ions at intermediate and low energies. The microscopic transport model UrQMD is employed to study the thermal vorticity of hot and dense nuclear matter formed in non-central Au + Au collisions at center-of-mass energies 7.7≤sNN≤62.4 GeV. The whole volume of an expanding fireball is subdivided into small cubic cells. Then, we trace the final Λ and Λ¯ hyperons back to their last interaction point within a certain cell. Extracting the bulk parameters, such as energy density, net baryon density, and net strangeness of the hot and dense medium in the cell, one can obtain the cell temperature and the chemical potentials at the time of the hyperon emission. To do this, the extracted characteristics have to be fitted to the statistical model (SM) of ideal hadron gas. After that, the vorticity of nuclear matter and polarization of both hyperons are calculated. We found that the polarization of both Λ and Λ¯ increases with decreasing energy of heavy-ion collisions. The stronger polarization of Λ¯ is explained by (i) the slightly different freeze-out conditions of both hyperons and (ii) the different space–time distributions of Λ and Λ¯.