Greater decentralization of modern IT environments, driven by distributed infrastructure, IoT devices, etc., has highlighted the limitations of traditional perimeter based security models, which are based on the assumption that the internal network is trusted, while threats exist exclusively outside of it. Implicit trust and broad internal access that perimeter environments have can create – and do create – favorable conditions for lateral movement, insider misuse, and unauthorized access. This paper examines Zero Trust Architecture (ZTA) as a security paradigm designed to address these weaknesses. In parallel, the paper analyzes Li-Fi (Light Fidelity) communication as an alternative wireless technology whose physical properties, including spatial signal limitation and reduced penetration through walls, offer significant cybersecurity advantages compared to conventional radio frequency systems, but since the physical environment alone does not guarantee protection, cryptographic protection mechanisms in Li-Fi environments are emphasized. By combining the Zero Trust model with Li-Fi communication and secure key management mechanisms, a layered approach is provided for securing sensitive internal wireless communication against eavesdropping, message manipulation, and unauthorized access.

In modern pharmaceutical quality control, accelerating analytical procedures while maintaining high accuracy is a key priority. This study focuses on optimizing analysis times by transferring classical UV/VIS spectrophotometric methods to a microplate reader platform. The model method chosen for this research was the determination of lysozyme enzymatic activity, conducted in accordance with the current Japanese Pharmacopoeia monograph. The underlying assay mechanism is based on spectrophotometrical measurement of the rate of absorbance decrease of a Micrococcus luteus bacterial suspension at approximately 450 nm. This decrease is a result of enzymatic hydrolysis of the cell wall and is directly proportional to the sample's activity relative to an official reference standard. The adapted method was verified and fully transferred from a standard cuvette-based spectrophotometer to a microplate reader format. This transfer enables simultaneous analysis of a large number of samples, resulting in significant time savings and higher throughput. Technical challenges encountered during the transition were successfully resolved by optimizing critical experimental parameters, including sample and reagent concentrations, volumes, reagent addition order, and reaction times, thereby ensuring strict result equivalence. The optimized method was successfully applied to three commercial products: Lysobact lozenges, Lysobact Junior oromucosal spray, and Lysoderm cream. Ultimately, verification of this model demonstrates that transferring to microplate readers enables high sample throughput while maintaining required accuracy and precision. This paper provides practical guidance for adapting classic UV/VIS spectrophotometric methods to modern technologies, improving efficiency in drug quality control.

This paper presents a robust discrete-time sliding mode controller (DT–SMC) for a bidirectional DC/DC converter that is used as an energy storage interface in DC microgrids. The proposed controller is implemented in a hierarchical cascaded control structure comprising an inner current loop and an outer voltage loop, together with a current-reference limiter and duty-cycle saturation. Both loops adopt DT–SMC to achieve fast sampled-data tracking under nominal non-saturated operation. A multirate framework is implemented to balance dynamic performance, control accuracy, and computational complexity. To improve disturbance rejection, disturbance estimators (DEs) based on the sliding variable are incorporated in both loops and equipped with an anti-windup compensation to suppress error accumulation. The controller requires only the converter current and terminal voltages, facilitating practical digital implementation with fixed-frequency pulse-width modulation (PWM). Simulation results compare the proposed method with benchmark cascaded DT–PI and STA–SMC controllers, while experimental tests on a laboratory prototype confirm its practical feasibility. The presented results indicate chattering mitigation through reduced duty-cycle variation, accurate reference tracking, fast transient response, and disturbance rejection under the tested operating conditions.

This laboratory manual supports practical study of programmable logic controllers and industrial automation equipment. Using a didactic workstation based on the Schneider Electric Modicon M340 PLC, it describes the rack, power supply, processor, digital and analog I/O modules, high-speed counter, variable-frequency drive, command panel, sensors, induction motor, and CANopen communication. It covers addressing and variable types, the Unity Pro XL development environment, PLC programming languages with emphasis on FBD, PLC-to-computer communication, and program transfer. Dedicated sections explain several methods of controlling the variable-frequency drive, CANopen integration, and laboratory examples, including measurement of motor speed with an inductive sensor.

Proper nutrition plays an important role in shaping our thinking and behaviour, and influences how food intake affects our emotions. The aim of the work was to assess the dietary habits and mental health of students. The study is a quantitative, cross-sectional research with observational-analytical methods. Students were selected using the convenience sampling method. Out of the total number of participants who participated in the study N=805. More frequent consumption of cakes/biscuits, fresh fruits, salad/raw vegetables, lemonade/soft drinks, meat/sausages and fish/seafood positively correlates with positive mental health. The development of the participants’ sense of coherence directly positively correlates with more frequent consumption of fresh fruit, lemonade/soft drinks and meat/sausages. Participants who consume fresh fruit, salad/raw vegetable, and lemonade/soft drinks less frequently perceive higher levels of stress. Frequent consumption of lemonade/soft drinks is negatively associated with anxiety, and along with meat/sausages, with depressive symptoms. Mental health correlates with the food categories cakes/biscuits, fresh fruit, salad/raw vegetable, lemonade/soft drinks, meat/sausages, fish/seafood, and fast/canned food.

Objective. The aim of this study was to assess oral hygiene habits, as well as awareness and knowledge among undergraduate students at a Faculty of Medicine in Bosnia and Herzegovina. Methods. This cross-sectional study was conducted at the Faculty of Medicine in Foča and included 333 students across three study programs: Medicine (M), Nursing (N), and Special Education and Rehabilitation (SER). The questionnaire was used to obtain demographic information, as well as data on oral hygiene habits and knowledge of oral health. Results. The largest proportion of students (56.2%) brush their teeth twice daily. A higher percentage of N and SER students brush their teeth longer than M students (p=0.004). Students most often replace their toothbrushes every 3 months or sooner (76.3%); 58.9% regularly visit a dentist; and 61% report no oral health problems. Only 14.4% of students believe that dental plaque dysbiosis is the cause of caries, while more than half of the students (53.5%) do not know the impact of dental plaque. Additionally, more than one-third of students (35.7%) are unaware of preventive measures for oral disease. A greater number of M and N students than SER students reported that oral health is related to cardiovascular disease (p=0.002), and more M students reported that it is related to cancer compared to SER students (p=0.032). Conclusion. The results of this study indicate limited knowledge of oral health among students across all three study programs, underscoring the need to improve oral health education for health sciences students.

The flue gases from coal fired thermal power plants, contain combustion gases (SO₂, NOₓ, CO, CO₂) and fine particles of fly ash. The concentration of sulfur oxides in the flue gas depends on the sulfur content in the coal. The flue gas desulfurization (FGD) process at TPP Ugljevik utilizes a wet scrubbing method, where a limestone suspension serves as the absorbent medium for sulfur oxides, with gypsum as a byproduct. Comparative analysis of emission levels before and after the FGD system installation indicates that the applied desulfurization technology is highly effective. The efficiency of the desulfurization plant ranged from 83.91% to 100%, depending on the inlet concentration of SO₂ in the flue gas. Estimates show that the FGD plant, depending on the intensity of operation, can annually remove between 7,000 and 55,800 tons of sulfur, with by-product gypsum production ranging from 3,660 to 29,280 tons. The implementation of this flue gas purification process significantly reduces the impact on the environment and ambient air pollution caused by sulfur oxides. For economic reasons, the plant is unfortunately unable to operate continuously. Keywords: Flue gases, SO₂ emissions, desulfurization, wet scrubbing process.

Because man strives to ensure the comfort in living and working spaces, there is a lot of air conditioning devices to achieve the desired temperature. Bacteria from the genus Legionella is a pathogenic bacterium that can cause the disease to occur in very severe form. It most often inhabits water systems created by human activity, among which are air conditioning devices, which is why there is a need to test factors that favors bacteria colonization. The study included 79 facilities from the territory of the Federation of Bosnia and Herzegovina, of which 42 or 53.2% facilities with centralized, and 37 or 46.8% facilities with individual air conditioning devices. Data were collected using a survey and laboratory analysis of samples. The analysis was performed individually, taking into account the different requirements and complexity of the two types of air conditioning devices. The objectives were related to the correlation between the age, distribution installation material, project, the maintenance dynamics and the need to use the air conditioner with Legionella spp. colonization. The results indicate a positive influence of the air conditioner age and steel distribution installation on the Legionella spp. colonization. Significant correlation was not observed between the collected survey responses (project, maintenance and the air conditioner use frequency) and the Legionella spp. colonization. The identification of factors that positively correlate with the presence of Legionella spp. in air conditioning devices has significant public health and technical contribution, especially in the context of legionellosis prevention, the implementation of adequate monitoring and maintenance.