Comment on star-star relations in statistical mechanics and elliptic gamma-function identities

We prove a recently conjectured star-star relation, which plays the role of an integrability condition for a class of 2D Ising-type models with multicomponent continuous spin variables. Namely, we reduce this relation to an identity for elliptic gamma functions, previously obtained by Rains.Comment: 8 pages, 3 figure

Evolution of kinklike fluctuations associated with ion pickup within reconnection outflows in the Earth's magnetotail

Magnetic reconnection (MR) in Earth's magnetotail is usually followed by a systemwide redistribution of explosively released kinetic and thermal energy. Recently, multispacecraft observations from the THEMIS mission were used to study localized explosions associated with MR in the magnetotail so as to understand subsequent Earthward propagation of MR outbursts during substorms. Here we investigate plasma and magnetic field fluctuations/structures associated with MR exhaust and ion-ion kink mode instability during a well documented MR event. Generation, evolution and fading of kinklike oscillations are followed over a distance of 70 000 km from the reconnection site in the midmagnetotail to the more dipolar region near the Earth. We have found that the kink oscillations driven by different ion populations within the outflow region can be at least 25 000 km from the reconnection site.Comment: 11 pages, 4 figure

Briquetting the Carbon Phase from the Sludge Ponds at the Anzhersk Deposit

The briquetting of coal slurries from the Anzhersk deposit in the Kuznets Basin is investigated. Petroleum binder and sodium lignosulfonate are employed. The solid carbon phase from the sludge ponds (ash content up to 35%) has adequate briquetting properties when petroleum binder is added. The use of sulfite waste liquor at pressures of 80–100 MPa yields mechanically strong briquets that require additional water protection

Influence of ion-beam treatment on structure and defor-mation resistance of 12Cr1MoV steel under static, cyclic and dynamic loading

Features of modification of structure and properties of 12Cr1MoV steel subjected to ion-beam irradiation by zirconium ion beam have been investigated with the use of optical and electron microscopy, and microhardness measurement. It was shown that after the treat-ment the modification occurs across the entire cross-section of specimens with the thickness of 1 mm. Changes in mechanical properties of these specimens under static, cyclic and impact loading were interpreted in terms of identified structure modifications

Case of soil surface chromium anomaly of a northern urban territory - preliminary results

AbstractThe aim of this paper is to present some results of a soil survey conducted at a northern city in Russia and analysis of origin of spots polluted by chromium. During the survey, 101 soil specimens were taken from different parts of the city using squared grid system with a spatial resolution of 250m. Two soil specimens were also taken from distant background locations to exclude the influence the pollutant sources. Chemical analysis was performed on soluble and total forms of heavy metals, mineral oil products, as well as other concentrations of parameters were measured. According to spatial distribution of total chromium concentrations, two spots with high level of pollution have been recognized. Mean concentration of total chromium in the spots subgroup is ten times higher than in the subgroup of comparison. It was suggested that the origin of anomalous pollution is not associated with the industrial activity and could not be explained by atmospheric deposition only

Legibility of Textbooks: A Literature Review

AbstractThe purpose of the study was to analyse findings in the field of the textbooks’ legibility, readability and visual word recognition. The paper focuses on the most significant findings for comprehending the texts’ spatial characteristics during reading, word and letter recognition. The aim of the study was to analyse the factors which have induced inconsistencies between the findings acquired by scientists, as well as to compare findings which continually lead to progression in this field

Comparison of artificial neural network, random forest and random perceptron forest for forecasting the spatial impurity distribution

The paper is present a comparison of modern approaches for predicting the spatial distribution in the upper soil layer of a chemical element chromium (Cr), which had spots of anomalously high concentration in the investigated region. The distribution of a normally distributed element copper (Cu) was also predicted. The data were obtained as a result of soil screening in the city of Tarko-Sale, Russia. Models based on artificial neural networks (multilayer perceptron MLP), random forests (RF), and also a model based on a random forest in which MLP used as a tree - a random perceptron forest (RMLPF) - were considered. The models were implemented in MATLAB. Approaches using artificial neural networks (MLP and RMLPF) were significantly more accurate for anomalously distributed Cr. Models based on RF algorithms proved to be more accurate for normally distributed copper. In general, the proposed model RMLPF was the most universal and accurate. © 2018 Author(s)

Quantitative magnetotail characteristics of different magnetospheric states

Quantitative relationships allowing one to compute the lobe magnetic field, flaring angle and tail radius, and to evaluate magnetic flux based on solar wind/IMF parameters and spacecraft position are obtained for the middle magnetotail, <i>X</i>=(–15,–35)<i>R<sub>E</sub></i>, using 3.5 years of simultaneous Geotail and Wind spacecraft observations. For the first time it was done separately for different states of magnetotail including the substorm onset (SO) epoch, the steady magnetospheric convection (SMC) and quiet periods (Q). In the explored distance range the magnetotail parameters appeared to be similar (within the error bar) for Q and SMC states, whereas at SO their values are considerably larger. In particular, the tail radius is larger by 1–3 <i>R<sub>E</sub></i> at substorm onset than during Q and SMC states, for which the radius value is close to previous magnetopause model values. The calculated lobe magnetic flux value at substorm onset is ~1GWb, exceeding that at Q (SMC) states by ~50%. The model magnetic flux values at substorm onset and SMC show little dependence on the solar wind dynamic pressure and distance in the tail, so the magnetic flux value can serve as an important discriminator of the state of the middle magnetotail.<br><br> <b>Key words.</b> Magnetospheric physics (solar windmagnetosphere- interactions, magnetotail, storms and substorms