Abstract This paper investigates the energy-efficient resource allocation algorithm for a massive multiple input multiple output (MIMO) system, in which each base station adapts the number of antennas to the daily load profile. Our paper examines the effect of two user location distribution (ULD) models, on the energy-efficiency (EE) of load adaptive masive MIMO system. We propose a resource allocation strategy to adapt the number of antennas based on tracking variations of ULD and cell loading maximizing the EE. We also evaluate impact of cell size, available bandwidth and output power level of the BS on EE at different cell loading.

The primary objective of this study is to analyze the self-assessment of the mental and physical health of young women from the effects of programmed recreational activities in a three-month period. The sample is composed of 35 women (20 - 40 years old). For a sample of variables in the assessment of mental and physical health, standardized instruments were used: THE HAD scale - Hospital Anxiety and Depression Scale (for mental health assessment) and EQ thermometer (for physical health assessment) The results of the overall condition of all participants before the start of the experimental procedure, 24 participants had no symptoms of depression, 8 participants had a borderline condition, and 3 participants with depressive disorder. After three months of recreational treatment, 30 of the participants have no symptoms of depression, 3 participants have borderline condition and 2 participants with depressive disorder. When it comes to the self-assessment of anxiety in the initial state, it was noted that 26 participants of the experiment had no signs of anxiety, 6 participants had a borderline state of anxiety, while 3 participants had anxiety disorders, of which 2 participants slightly above the limit state and one participant with a particularly high number of points indicating a more severe state of anxiety. At the end of the experiment, 31 participants had no signs of anxiety, 4 had a borderline state and 1 person with a severe anxiety condition. Before the start of recreational activities, one participant rated their physical health as extremely poor and 3 people rated their health as poor. The largest number of participants before the experiment, 16 of them, rated their physical health slightly above average, 10 women rated their physical health as excellent and 5 women rated themselves the best imaginable physical health. After the experiment, only 4 participants estimated lower and average self-health, above average 6, 20 women claimed to have excellent health and 5 participants in the experiment claimed to be in the best physical health imaginable. Keywords: Women, recreation, self-assessment, depression, anxiety, physical health.

Summary: In the northern synclinorium of Kreka coal basin, lignite mine ”Lipnica” was opened in 1950 in Lipnica settlement nearby Tuzla city. During the exploitation period, mine produced 40 million tons of lignite. By extracting the coal reserves, mine was shut down in 1991. Underground caves were filled by classical methods present in underground mining and all entries are sealed. The ground infrastructure remained preserved and has had usable values in three periods when infrastructure was used for various purposes. Conversion for re- use of mining infrastructure is not defined by any categorisation for infrastructure conversion use as the planning element of sustainable development for active or shutdown mines. The article defines categories of sustainable development based on utilizing mine infrastructure on the sample of “Lipnica” mine. The universality of categorisation points out the possible options of optimal re-use of coal mine infrastructure, indicating implementation of a mining company sustainable development concept, either in government or private ownership. Keywords: categorisation, sustainable development, business incubator, Lipnica mine

Safety risk management in Bosnian-Herzegovinian underground coal mines is not based on a systematic approach and standardized risk management methods. Mostly there is a traditional approach present, i.e. reaction to incidents/accidents that happen. This paper aims to point out the need for proactive approach introduction with an emphasis on importance of ventilation systems failure mechanism simulation analysis in planning of people and property defense and rescue in crisis situations. Based on ventilation parameters measuring results for a given research site (brown coal mine), a model was developed on which a simulation analysis was performed for three characteristic ventilation failure cases: spontaneous oxidation at the longwall exit, collapse at the entrance to the longwall and methane outburst - preparation of a new excavation field. VnetPC and CFD “Fluent” software packages were used to simulate mine ventilation. Keywords: risk management, brown coal mine, safety, ventilation system, longwall, simulation analysis, VnetPC, Fluent.

Wastewater from industrial process of uranium ore mining contains a large amount of this radioactive pollutant. Regarding the advantages of biosorption, it was found that varieties of biomasses such as agricultural waste, algae and fungi are effective for uranium removal. However, there is limited research on cyanobacteria, therefore, cyanobacteria, Anagnostidinema amphibium (CAA) was investigated by batch method for the first time for biosorption of uranium (VI). Optimization of biosorption parameters showed that maximum removal efficiency of 92.91% was reached at pH range of 9-11 with 50 mg of cyanobacteria to 100 mg/L U(VI) initial concentration, at 25 °C within 40 min. Used biosorbent exhibited very good selectivity for U(VI) ions and reusability in IV sorption/desorption cycles. Characterization of CAA surface was performed by FTIR, EDS, EDXRF and SEM analysis and it has shown various functional groups (CONH, COOH, OH, PO alkyl group) and that it is very rich in elements such as iron, potassium and calcium. In binary systems, contained of U(VI) and selected ions, CAA exhibits very good selectivity towards U(VI) ions. Kinetic data revealed the best accordance of experimental data with the pseudo-second-order model, and isotherms data agreed with Freundlich model. Thermodynamic data implied that U(VI) biosorption process by A. amphibium exhibited spontaneity and modelling of the investigated process showed that the adsorption of uranium ions occurs mainly via peptidoglycan carboxyl groups. Overall results show that these cyanobacteria with a maximum sorption capacity of 324.94 mg/g have great potential for the processing of wastewater polluted with uranium (VI).

Abstract Cathodic protection system is commonly employed approach for the protection of the metallic infrastructure placed in electrolyte against corrosion. Adequate design of the cathodic protection system requires the determination of electrical potential and current density distribution on the protected object surface that meets the defined criteria. In this paper, the application of the direct boundary element method in conjunction with Newton-Raphson method was considered for the calculation of the electric potential and current density distribution on the surface of the cathodically protected underground object. The considered method was applied on the sacrificial anode cathodic protection system of the underground pipeline. The non-linear boundary conditions of the electrode surfaces of the cathodic protection system are taken into account. The method was used to determine the current density and electric potential distribution on the external wall of the protected pipeline.

Using the CO molecule as target, we investigate high-order harmonic generation by a bichromatic elliptically polarized laser field. This field consists of two elliptically polarized components with the commensurable frequencies and mutually orthogonal semi-major axes. Both odd and even harmonics are emitted and their ellipticity can be large depending on the values of the laser-field parameters. It is often the case that the ellipticity of subsequent odd and even harmonics is substantially different so that, in order to produce a series of high-order harmonics with similar ellipticity, it is beneficial if the emission of odd or even harmonics is suppressed. In this paper we explore how this can be achieved using the ellipticity of the laser-field components and the relative phase as control parameters. For some values of these parameters it is possible to produce a comb of odd or even harmonics with similar ellipticity. These harmonics can later be employed for various applications the example of which is the generation of an elliptically polarized attosecond pulse train.

Industry 4.0 has a significant impact on the automation of production processes, by causing numerous changes in three segments: companies, technology and workers. Developed countries worldwide have their own strategies on Industry 4.0, which offer guidelines on its implementation in production processes, with the aim of their complete flexible automation. The core technologies on which Industry 4.0 rests have led to a complete transformation in production processes, especially in the automotive industry. The basic technology of Industry 4.0 is robot technology, i.e., the implementation of industrial and service robots in production processes. The paper provides an analysis of the implementation of industrial robots and service robots in the automation of production processes in the automotive industry with a focus on China. The analysis of the automation of production processes of the automobile industry in China was carried out for two reasons. The first is that China has a growing middle-class population, so demographic trends are encouraging the growing demand for certain products, such as cars. Another reason is that in China (as in Japan, Russia and Western Europe) the average age of factory workers is increasing (the labor force is older), thus the performance of certain tasks becomes more difficult so greater efficiency is not achieved. The paper analyzes vehicle production in China, as well as the readiness of production processes in the automotive industry for the implementation of Industry 4.0.

Abstract The global Covid-19 pandemic led to the turn toward online learning and the need to adapt to new ways of English foreign language (EFL) teaching. This mixed-methods research aimed to examine teacher attitudes, well-being, and coping strategies related to online EFL teaching. The results indicated that Croatian EFL teachers had a positive attitude toward online teaching and acknowledged the importance of being digitally competent. EFL teachers were unsure about their ability to deal with online teaching and indicated their need to improve their IT skills. They revealed more negative than positive responses regarding their well-being and showed that they tried to actively cope during the pandemic. Results also showed better coping strategies among female teachers.

Abstract Frequent changes in fiscal policies are the main cause of credit risk. To prevent households from increasing their non-performing loans, the government can use various policies and instruments. One of these tools is tax regulations, with a particular focus on the value-added tax. This paper examines whether tax policies have affected non-performing household loans in Turkey over the period from 2017 to 2021. To acquire meaningful empirical results, the Autoregressive Distributed Lag (ARDL) cointegration model have been applied. The results of analysis indicated that the effect of tax regulations on non-performing household loans is quite strong. It can be demonstrated that the strength of the income effect generated by tax cuts might be robust.

The research relates to determining the dependence of the strength and hardness, as well as the pH factor and solubility in water, of pellets made based on dolomite powder on the type and concentration of the binder. During the research, the technological parameters of the pelletizing device (speed and inclination of the disk, dosing speed of powder and binder suspension, and mixing time) were kept constant. Variations were made in the concentration of starch and molasses binder at values of 1.0, 2.5, and 4.0% and the control sample of 2.0 %. The purpose of pellets made of dolomite powder is to correct the pH factor of agricultural soil. The obtained results indicate that the production of pellets for the stated purpose requires an optimal choice of binder and its concentration due to the influence on the qualitative indicators of the pellet itself from dolomite powder. The research results are a partial extract of the Study: “Investigation of the optimal technology for the production of dolomite pellets from the “Očura” deposit for agriculture, Phase I”. Keywords: pellet, agriculture, binder concentration, strength, hardness, pH of pellets.

Background: MRI techniques of the lumbar spine have not provided data on the effect of gravity on the spine and on the relationship of anatomic structures during its action. Because conventional MRI examinations of the spine are usually performed in the supine position these are often exacerbated by standing upright and are not evident in the supine position the loading conditions differ from those known to cause symptoms in patients with lumbar instability. Axial loading imaging may improve diagnostics in the clinical management of LBP and lead to appropriate treatment decisions. Objective: The aim of this study is to determine the significance of alMRI in detecting the morphologic changes of the lumbar spine caused by axial loading and to compare it with conventional MRI images of the lumbar spine without loading. Methods: The study was conducted as a prospective, descriptive clinical trial. Imaging was performed with a MRI 1.5 T in the head-first supine position. Imaging was performed in two acts: without load and under load. Loading for alMRI was performed with the DynaWell L-Spine device. The onset of loading was 10 minutes before the start of alMRI. The loading continued throughout the imaging procedure. The height of the IV, AP and LL diameters of IV, IV disk surface area, DSCA and width of the IV foraminas before and under load was measured. Results: After evaluating the changes in the height and size of the lumbar disks, the size of the DSCA, and the narrowing of the intervertebral foramina significant differences were found between the images before and after axial loading. Conclusion: alMRI provides information on morphological changes of all segments of the lumbar spine. This data represents significant information that can lead to more accurate and effective treatment of LBP.