Application of numerical and physical modeling in designing of an X-ray luminescence separator intended for separation of ores containing luminescent minerals

The paper demonstrates the application of numerical and physical modeling to justify the design of the X-ray fluorescence separator’s material handling system. The Rocky DEM software package is a numerical modeling tool that uses the discrete element method as a mathematical apparatus. In order to increase the efficiency of the X-ray luminescence separation, the authors suggest including an additional element in the separator’s material handling system, i.e., a drum spreader that combines a handling device and an actuating mechanism. It was found out that the best loading of the drum spreader cells, in which the number of several pieces in one cell is reduced by at least 15%, is provided by a Vibrating feeder conveyor with a triangular cross-section of the profiled part of the tray compared with the tray of parabolic cross-section. In addition, the triangular section provides a double decrease in the number of pieces with rotational movement around their axes and, accordingly, an increase of at least 5% in the average velocity of the ore flow movement along the tray. The simulation of the material handling system has shown the need to reduce the height of the end partition of the drum spreader between the cells to 45 mm, which eliminates the collision of ore pieces with the partition and subsequently, their movement in the direction of rotation of the drum spreader on its outer surface, as well as the unpredictable escape of the ore pieces beyond the working space of the separator.

The role of collegiality in academic review, promotion, and tenure

Review, promotion, and tenure (RPT) processes at universities typically assess candidates along three dimensions: research, teaching, and service. In recent years, some have argued for the inclusion of a controversial fourth criterion: collegiality. While collegiality plays a role in the morale and effectiveness of academic departments, it is amorphic and difficult to assess, and could be misused to stifle dissent or enforce homogeneity. Despite this, some institutions have opted to include this additional element in their RPT documents and processes, but it is unknown the extent of this practice and how it varies across institution type and disciplinary units. This study is based on two sets of data: survey data collected as part of a project that explored the publishing decisions of faculty and how these related to perceived importance in RPT processes, and 864 RPT documents collected from 129 universities from the United States and Canada. We analysed these RPT documents to determine the degree to which collegiality and related terms are mentioned, if they are defined, and if and how they may be assessed during the RPT process. Results show that when collegiality and related terms appear in these documents they are most often just briefly mentioned. It is less common for collegiality and related terms to be defined or assessed in RPT documents. Although the terms are mentioned across all types of institutions, there is a statistically significant difference in how prevalent they are at each. Collegiality is more commonly mentioned in the documents of doctoral research-focused universities (60%), than of master's universities and colleges (31%) or baccalaureate colleges (15%). Results from the accompanying survey of faculty also support this finding: individuals from R-Types were more likely to perceive collegiality to be a factor in their RPT processes. We conclude that collegiality likely plays an important role in RPT processes, whether it is explicitly acknowledged in policies and guidelines or not, and point to several strategies in how it might be best incorporated in the assessment of academic careers.

Addiction recovery stories: Jerome Carson in conversation with Lisa Ogilvie

Purpose The purpose of this paper is to explore the accomplishments of those who realise addiction recovery. To the best of the authors’ knowledge, this is the first in a series of recovery stories, where candid accounts of addiction and recovery are examined. In doing so, shared components of recovery are considered, along with the change and growth necessary to facilitate it. Design/methodology/approach The CHIME (Connectedness, Hope, Identity, Meaning and Empowerment) framework comprises five elements important to recovery. It provides a standard to qualitatively study mental health recovery, having also been applied to addiction recovery. In this paper, an additional element for Growth has been introduced to the model (G-CHIME), to consider both recovery and sustained recovery. A first-hand account of addiction recovery is presented, followed by a semi-structured e-interview with the author of the account. This is structured on the G-CHIME model. Findings This paper shows that successful and sustained recovery from alcohol addiction can be effectively explained using the G-CHIME model. Each element was well represented in the described process of reaching recovery. Originality/value Each account of recovery in this series is unique, and as yet, untold.

Design and Development of Novel Hybrid Precoder for Millimeter-Wave MIMO System

Power consumption and hardware cost reduction with the use of hybrid beamforming in large-scale millimeter wave MIMO systems. The large dimensional analog precoding integrates with the hybrid beamforming based on the phase shifters including digital precoding with lower dimensionality. The reduction of Euclidean distance between the hybrid precoder and fully digital is the major problem to overcome the minimization of resultant spectral efficiency. The issue formulates as a fully digital precoder’s matrix factorization problem based on the analog RF precoder matrix and the digital baseband precoder matrix. An additional element-wise unit modulus constraint is imposed by the phase shifters on the analog RF precoder matrix. The traditional methods have a problem of performance loss in spectral efficiency. In the processing time and iteration, high complexities result in optimization algorithms. In this paper, a novel low complexity algorithm proposes which maximizes the spectral efficiency and reduces the computational processing time.

The legitimacy of Tsarist authority over the peoples of Siberia in the late 16th to early 18th centuries

The article studies the methods that substantiated the legitimacy of the power of the Russian monarch over the vast territories of Siberia. The context of this study is the Russian political culture of the late 16th to early 18th centuries. Based on information from chronicles as well as diplomatic and administrative documents, the authors identify and systematize the main political, ideological, and legal arguments that were most often used by the Russian government to justify the Tsars rule over Siberia. The arguments can be divided into two groups according to the target audience: the first group was intended for conversation with the heads of foreign countries, the second one addressed the Siberian peoples and also the Russian people broadly. In foreign policy, the representatives of the Moscow Tsar emphasized the antiquity and the strength of the bond between these territories and the Russian state. The diplomats tended to exaggerate the scale of the Russian military, socio-economic, political, and cultural (religious) development of the new territories. At the same time, they were silent about the resistance of the local population to the tsarist servicemen. At home the authorities applied other legal arguments to bolster their legitimacy. In interaction with indigenous populations, the Russian governors and service people usually forced the communities (in the form of an ultimatum) to accept the claim that the Tsar owned the Siberian lands as a fiefdom. With this the socio-political status of the Siberian peoples radically changed: they became subjects to the Russian Tsar, as kholops or yasak-payers. The Russian combatants and colonists, in direct contact with the indigenous population, informed the Siberian peoples about recent government directives and fully identified with the official claim to authority. In the eyes of the Russian population, an additional element was the religious and political idea that the Tsar had been chosen by God, from which followed the duty to expand the Russian Orthodox tsardom.

Methodology of 3D Scanning of Intangible Cultural Heritage—The Example of Lazgi Dance

Traditional dance is one of the key elements of Intangible Culture Heritage (ICH). Many scientific papers concern analysis of dance sequences, classification and recognition of movements, making ICH data public, creating and visualising 3D models or software solutions for learning folklore dances. These works make it possible to preserve this disappearing art. The aim of this article is to propose a methodology for scanning folklore dances. The methodology was developed on the basis of capturing 3D data via an optical motion capture system with a full body Plug-in Gait model that allows for kinematic and kinetic analysis of motion sequences. An additional element of this research was the development of a hand model with which it is possible to precisely analyse the fingers, which play a significant role in many dances. The present methodology was verified on the basis of the Lazgi dance, included in the UNESCO ICH list. The obtained results of movement biomechanics for the dance sequence and the angles of the fingers indicate that it is universal and can be applied to dances that involve the upper and lower body parts, including hand movements.

Dopaminergic challenge dissociates learning from primary versus secondary sources of information

SummarySome theories of human cultural evolution posit that humans have social-specific learning mechanisms that are adaptive specialisations moulded by natural selection to cope with the pressures of group living. However, the existence of neurochemical pathways that are specialised for learning from social information and from individual experience is widely debated. Cognitive neuroscientific studies present mixed evidence for social-specific learning mechanisms: some studies find dissociable neural correlates for social and individual learning whereas others find the same brain areas and, dopamine-mediated, computations involved in both. Here we demonstrate that, like individual learning, social learning is modulated by the dopamine D2 receptor antagonist haloperidol when social information is the primary learning source, but not when it comprises a secondary, additional element. Two groups (total N = 43) completed a decision-making task which required primary learning, from own experience, and secondary learning from an additional source. For one group the primary source was social, and secondary was individual; for the other group this was reversed. Haloperidol affected primary learning irrespective of social/individual nature, with no effect on learning from the secondary source. Thus, we illustrate that neurochemical mechanisms underpinning learning can be dissociated along a primary-secondary but not a social-individual axis. These results resolve conflict in the literature and support an expanding field showing that, rather than being specialised for particular inputs, neurochemical pathways in the human brain can process both social and non-social cues and arbitrate between the two depending upon which cue is primarily relevant for the task at hand.

COMPARATIVE ANALYSIS OF NATM CONSTRUCTION TECHNOLOGIES OF DNIPRO METRO ESCALATOR TUNNEL

Purpose. On the basis of the comparative analysis to carry out a substantiation of the most expedient and rational way of strengthening of a weak massif during a construction of Dnipro metro escalator tunnels by NATM. Methodology. To achieve this goal, an analysis of construction technologies in weak soils was conducted. The most used technologies are Forepoling Umbrella System (FUS), artificial ground freezing and chemical cementation. The peculiarities of carrying out each of the technologies for the conditions of inclined production were analyzed. It is determined how each of the technologies is applied to escalator tunnels and implements the strengthening of weak soil. Findings. The advantages and disadvantages of three technologies for fixing weak soil around the escalator tunnel are identified. Based on comparative analysis, it was found that the only technology that provides increased strength parameters of loamy soils, characteristic for the upper part of the escalator tunnel of the Dnipro metro, is the technology of chemical strengthening (cementation). In some cases, if necessary, short sections of sloping course, characterized by particularly weak soil, can be supported by several pipes, without creating a continuous leading mount. The results of the analysis are the basis for further substantiation of cementation, which creates a multilayer system "reinforced soil massif – temporary fastening – permanent lining". Originality. Based on the results of comparative analysis of three technologies for escalator tunnel construction by NATM, it is proved that the use of cementation not only increases the strength of the soil during drilling, but also further in operation serves as an additional element of the multilayer system "reinforced soil massif – temporary fastening – permanent lining". Practical value. In the course of research, the substantiation of cementation as the most rational and effective technology of strengthening of the surrounding weak massif at construction of the Dnipro metro was carried out.

A review of methods in the field of detecting illegal open-pit mining activities

Illegal open pit mining might be a very dangerous activity both for the environment and also for the people living in its neighbourhood. This kind of activity is connected with environmental degradation, disruption of sustainable development and lack of the most critical last stage of the mine’s “life”, i.e. land reclamation. An additional element connected with illegal exploitation is the fact of breaking the law and stealing mineral resources. Monitoring of illegal exploitation is therefore an important aspect. The presented here review was intended to investigate which methods can be used directly to detect open pit mining sites and to evaluate their effectiveness. In the reviewed works a wide variety of methods have been used, ranging from manual methods, such as photo-interpretation, to a combination of automatic methods and photo-interpretation, to fully automatic methods. Based on the analysis, it was indicated that different types of classification (supervised, unsupervised, hybrid) are the most commonly u sed. Besides, radar interferometry, image fusion techniques, or images spectral similarity are also used.

The Szymkowiak’s over-expanded cycle in the rocker engine with the variable compression ratio – kinematics

The article discusses the innovative concept of the over-expanded thermodynamic cycle, the author of which is the Polish engineer-designer Mirosław Szymkowiak. This cycle is realized on the basis of a new and innovative, previously unknown design, of a piston-crankshaft linkage mechanism with the aid of an additional element known as a rocker arm. Additionally, the proposed mechanism allows for a smooth change of the compression/expansion ratio of the engine during its operation. In the beginning, the earlier conceptions of the rocker engine developed by Szymkowiak were presented, and then the main construction assumptions and kinematic calculations were described. It was confirmed, that the developed linkage has big potential in improving the engine's thermal efficiency by approximately 12% relative. Additionally, it significantly reduces the exhaust gas pressure, when the exhaust valve is opened, therefore, contributes to the reduction of the noise emitted by the engine.