On connection between evolution of troposphere fronts and changes of circulation regime in meteor zone

The interactions between the thermobaric fields at heights from 5 to 95 km at the beginning of a winter period are considered, based on experimental radar measurements of meteor drifts obtained in Frunze in November to December 1983. During this period the high atmosphere readily responds to even slight changes in the thermal regime of the stratosphere. The interdiurnal variations of average daily values of wind u, v, U, and azimuth phi are shown

Can accretion properties distinguish between a naked singularity, wormhole and black hole?

We first advance a mathematical novelty that the three geometrically and topologically distinct objects mentioned in the title can be exactly obtained from the Jordan frame vacuum Brans I solution by a combination of coordinate transformations, trigonometric identities and complex Wick rotation. Next, we study their respective accretion properties using the Page-Thorne model which studies accretion properties exclusively for $r\geq r_{\text{ms}}$ (the minimally stable radius of particle orbits), while the radii of singularity/ throat/ horizon $r<r_{\text{ms}}$. Also, its Page-Thorne efficiency $\epsilon$ is found to increase with decreasing $r_{\text{ms}}$ and also yields $\epsilon=0.0572$ for Schwarzschild black hole (SBH). But in the singular limit $r\rightarrow r_{s}$ (radius of singularity), we have $\epsilon\rightarrow 1$ giving rise to $100 \%$ efficiency in agreement with the efficiency of the naked singularity constructed in [10]. We show that the differential accretion luminosity $\frac{d\mathcal{L}_{\infty}}{d\ln{r}}$ of Buchdahl naked singularity (BNS) is always substantially larger than that of SBH, while Eddington luminosity at infinity $L_{\text{Edd}}^{\infty}$ for BNS could be arbitrarily large at $r\rightarrow r_{s}$ due to the scalar field $\phi$ that is defined in $(r_{s}, \infty)$. It is concluded that BNS accretion profiles can still be higher than those of regular objects in the universe.Comment: 17 pages, 12 figure

Longitudinal peculiarities of meridional circulation in lower thermosphere and mesosphere

Average monthly longitudinal profiles of geostrophic wind in winter are presented. Positive values correspond to meridional movements from north to south. It is concluded that the normal longitudinal meridional circulation is characterized by the presence of sectors where meridional flows do not change their direction in the course of time comparable with synoptic periods. The longitudinal distribution of meridional wind in middle latitudes taken from the analysis results of radiometeor and ionospheric stations observational data obtained in 1976 to 1980 are presented. Meridional winds have a longitudinal variability that is equivalent to both the warm and cold half years

Leaching kinetics of arsenic sulfide-containing materials by copper sulfate solution

The overall decrease in the quality of mineral raw materials, combined with the use of arsenic-containing ores, results in large amounts of various intermediate products containing this highly toxic element. The use of hydrometallurgical technologies for these materials is complicated by the formation of multicomponent solutions and the difficulty of separating copper from arsenic. Previously, for the selective separation of As from copper–arsenic intermediates a leaching method in the presence of Cu(II) ions was proposed. This paper describes the investigation of the kinetics of arsenic sulfide-containing materials leaching by copper sulfate solution. The cakes after leaching of arsenic trisulfide with a solution of copper sulfate were described using methods such as X-ray diffraction spectrometry (XRD), X-ray fluorescence spectrometry (XRF), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy analysis (EDS). The effect of temperature (70–90 °C), the initial concentration of CuSO4 (0.23–0.28 M) and the time on the As recovery into the solution was studied. The process temperature has the greatest effect on the kinetics, while an increase in copper concentration from 0.23 to 0.28 M effects an increase in As transfer into solution from 93.2% to 97.8% for 120 min of leaching. However, the shrinking core model that best fits the kinetic data suggests that the process occurs by the intra-diffusion mode with the average activation energy of 44.9 kJ/mol. Using the time-to-a-given-fraction kinetics analysis, it was determined that the leaching mechanism does not change during the reaction. The semi-empirical expression describing the reaction rate under the studied conditions can be written as follows: 1/3ln(1 − X) + [(1 − X) − 1/3 − 1] = 4,560,000Cu3.61e−44900/RT t. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.10.7347.2017/8.9Russian Science Foundation, RSF: 18-19-00186Funding: The research was funded by the Russian Science Foundation, grant number 18-19-00186. The SEM/EDS analyses were funded by State Assignment, grant number 10.7347.2017/8.9

The Influence of Thermal Baking Modes on the Electrical Properties of the Carbide Coating and its Strength with the Base

The article discusses the influence of thermal baking modes on the electrical properties of the carbide coating and its strength with the base. It is found that the electrical resistivity of the carbide coating applied by the baking method reflects the structural state of the material and allows optimizing the thermal regime of the process. By the value of the specific electrical resistance of the sintered coating, it is possible to predict the strength of its connection with the substrate

On the homology of the Harmonic Archipelago

We calculate the singular homology and \v{C}ech cohomology groups of the Harmonic archipelago. As a corollary, we prove that this space is not homotopy equivalent to the Griffiths space. This is interesting in view of Eda's proof that the first singular homology groups of these spaces are isomorphic