Mathematical modeling of pyroxene-magnetite crystalline shales elastic and acoustic properties

The analysis of the results of mathematical modeling of the influence of the format, mineral concentration and fracture of metamorphic crystalline shales of the Pishcha iron ore structure is presented. The aim of this work is to analyze the influence of mineral composition, types, orientation and concentration of mineral inclusions and microcracks on the acoustic and elastic properties of a group of samples of “quartz-magnetite-pyroxene” crystalline shales of Pishchans’ka iron ore structure. Based on the method of conditional moments, mathematical modeling of the influence of the format, orientation and content of mineral grains, as well as the concentration and format of cracking on the acoustic and elastic properties of rocks of the Pishchans`ka iron ore structure was performed. According to the obtained data, a weak effect of changes in the content of rock-forming minerals and a significant effect of different types of fractures on the value of elastic and acoustic anisotropy (10-40%) was proved. Elastic constants of models with layered and chaotic orientation of structural-textural elements are calculated. It is established that most models, as well as basic samples have a rhombic type of acoustic symmetry. When comparing the stereoprojections of the anisotropy parameters of real samples with the stereoprojections obtained during modeling, the authors found that in most samples there is a double system of cracking: chaotic and directed in the area of shale. The results of mathematical modeling showed that for models with ordered crack orientation, the change in the format and concentration of voids is a defining characteristic. This effect is significantly smaller for models with a chaotic arrangement of structural elements. It is proved that models with a combined (layered and chaotically oriented) type of fracture are the closest to real samples. The authors show that this technique allows you to create and operate models close to the real geological environment.

Development and Test of Rubber Wheel Full Hydraulic Drill in Coal Mine

In order to solve the problem of moving rig quickly and reducing labor intensity in the mine face with trackless transportation conditions, a solution of rubber wheel drill which meets the working conditions is put forward. The drilling rig adopts the configuration of double power and double system, the power comes from the engine when moving, to achieve walking, steering, braking and temporary stability, relocation and transfer of high efficiency and flexibility, the power comes from the motor when drilling, to achieve rotation, feed and auxiliary Angle adjustment, safe and pollution-free construction. After the assembly and debugging of the whole machine, ground simulation test and underground industrial test were carried out on the rig. The test results show that the rig has strong maneuverability, one person can complete the moving walking, the maximum walking speed is 20km/h, and the steering is flexible and the braking is safe. The maximum depth of drilling hole construction is 318m, the target area hit rate reaches 77.8%, the working performance is stable, the hydraulic system is stable, and all parameters meet the design requirements. The equipment provides new technical equipment for the mine drilling construction with trackless transportation conditions.

On the NS-DSSB unidirectional estimates in the SAMPL6 SAMPLing challenge

In the context of the recent SAMPL6 SAMPLing challenge (Rizzi et al. 2020 in J Comput Aided Mol Des 34:601–633) aimed at assessing convergence properties and reproducibility of molecular dynamics binding free energy methodologies, we propose a simple explanation of the severe errors observed in the nonequilibrium switch double-system-single-box (NS-DSSB) approach when using unidirectional estimates. At the same time, we suggest a straightforward and minimal modification of the NS-DSSB protocol for obtaining reliable unidirectional estimates for the process where the ligand is decoupled in the bound state and recoupled in the bulk.

Study on the Evolution Law of Fracture Field in Full-Mechanized Caving Mining of Double System and Extrathick Coal Seam

During the full-mechanized caving mining, the overburden strata in the double system and extrathick coal seam of the Datong mining area are largely damaged. Water and harmful gas in the old goaf may be discharged when overburden fractures evolve to the upper goaf, which poses a major threat to the normal production of the panel. To study the movement of overburden strata and the evolution of fracture field under the full-mechanized caving mining of the double system and extrathick coal seam, panel 8309 of Tongxin mine was taken as the research object; the evolution rule of fracture field in the full-mechanized caving mining of the double system and extrathick coal seam was obtained through field measurement and physical similar simulation. The results show the following: (1) the far-field and near-field key strata play a decisive role in controlling the fracture evolution of overburden strata. When the far-field key strata break and the development height of fractures reaches 220.9 m, panel 8309 is connected with the overburden goaf. (2) Based on the “O-shape circle” theory of mining fracture, with the continuous advance of the panel, the overburden breaks periodically, and a “fracture surface” with a certain angle of 61°–67° can be formed along with the advancing direction of the panel. (3) When the key strata are broken and the development height of fractures reaches the maximum, the fracture surface is formed as the “main fracture surface,” which is the only downward discharge pathway for goaf water and harmful gas. The overall shape fracture surface is “inverted trapezoid” in the upper part and “positive trapezoid” in the lower part. (4) Based on the field measurement of the water level of borehole and the observation of mine pressure, the correctness of the evolution law of the similar simulated fracture field is verified.

The end of the affair: Catholic plots and sinful detectives

The first paragraph of Greene’s The End of the Affair establishes a clear link between two of the major themes of the novel: storytelling and Catholicism. Maurice Bendrix, the first-person narrator, considers whether it is his craft as a professional writer that leads him to begin telling his story the way he does, or, were he a believer, whether the hand of God played a role in organizing the events that he retells. The order in which a story is told is pitted against the chronological order of the events depicted, this contrast in turn masking the one between human choice and divine intervention. The gist of the story is the affair Bendrix conducted with Sarah Miles, and its unexpected and unexplained end at her behest a year before the opening scene, at the height of the Blitz. That mystery is the crux of the plot, for Bendrix’s obsession with uncovering it leads him to hire a private detective, Parkis, whose exploits allow Greene to appropriate the narrative structure of detective fiction to frame his work, especially in what concerns what Franco Moretti called a “double system of meanings”, following Todorov’s work on detective fiction: the superficial level of investigation hides the deeper level of the crime which is only revealed at the end. My suggestion is that Greene’s novel operates under this system, superimposing it to his concerns with jealousy, religion, and how to tell it. The concern with God, however posits issues of authorship and narrative that go beyond the classical detective story. The interplay between narrative time and experienced time expressed in the novel’s initial paragraph is in this way rendered more complicated by a detective story’s reliance on its conclusion for it to “work”. Although the The End of the Affair opens by emphasizing its own opening, both title and structure point to the source of meaning: the end.

Emperors’ Nicknames and Roman Political Humour

SummaryThe article examines unofficial imperial nicknames, sobriquets and appellatives, from Octavian Augustus to Julian the Apostate, in the light of traditions of Roman political humour, and argues that in the political field during the Principate there were two co-existing competing modes of emperors’ naming: along with an official one, politically loyal, formalised and institutionally legitimised, there existed another – unofficial, sometimes oppositional and even hostile towards individual emperors, frequently licentious, humorously coloured and, in this regard, deeply rooted in Roman Republican traditions of political humour. Many of the known imperial nicknames and appellatives belong to a specific kind of folklore and express popular public opinion. They survived for us because of ancient authors’ interest in using such material for their literary and ideological intentions, particularly to express better the individual characteristics of the historical personages. But, for the very same purposes, Greek and Roman writers could invent some names and sobriquets, following special rhetorical and moralising principles, or mere love of ridicule. All in all, most imperial nicknames, both authentic and made-up, reveal a rather good quality of humour and mockery constructed by expressive linguistic devices and various rhetorical tropes. An apt derisive nickname marked anti-values, mocked the ruler’s badness and could vilify his reputation to the extreme, stigmatise his personality, or else become a widely-used quasi-cognomen. Many nicknames and appellatives were of ephemeral, ad hoc nature, their sense and effect largely dependent on the particular context; but, taken as a whole, they demonstrate the possible scope of and common trends in naming practice. The political system of the Principate and its very atmosphere of hypocrisy did promote double meaning and double thinking reflected in the double system of the rulers’ nomenclature. Imperial nicknames were a counter-hegemonic transcript and a weapon in the struggle for symbolic capital. All the efforts which many emperors took to control their nomina were ultimately powerless against the strength of the inevitable humorous counter-naming by the ruled.