Bauxite residue, also known as red mud (RM) is waste produced during alumina production in Bayer process. It is posing a significant threat to the enivorment due to its high alklalinity, fine particle size and complex structure various compounds. This study presents a sustainable, approach to its utilization, with focus on the recovery of valuable metals such as titanium. Different decarbonizing technologies were used presented in this work: hydrogen reduction without smelting in rotary kiln, high pressure leaching in an autoclave, ultrasonic spray pirolysis and aluminothermic reduction. Firstly red mud was subjected to hydrogen reduction in order to selectively remove iron, which can be used and transfered in the steel industry. Separation of Iron and solid residue was done using magnetic property of iron and magnetite, Solid residue is further processed in acid leaching with high pressure of oxygen in an autoclave. Leaching process optimizes various process parameters to extract titanium in the form of titanium oxy sulfate as well as iron and aluminium. Additionally, aluminum and iron solutions were also obtained by this process. The remaining solid residue, primarily composed of calcium sulphate and silica, was evaluated for potential use as an adsorbent in wastewater treatment. This innovative process demonstrates an efficient method of bauxite residue utilization with near zero waste concept, offering a promising solution to both environmental and industrial challenges. The planned improvement of proposed research strategy can be reached using solvent extraction and remelting process.

The UV-VIS method is an effective, non-destructive method that enables a better understanding of the electrolyte during corrosion. The aim of the study presented in this paper is to determine the existence of an organometallic complex in a 0.5 M NaCl solution with the addition of Rubus fruticosus L. leaf extract (RFLE). The experiments were conducted in a 0.5 M NaCl solution with the addition of RFLE (5 g/L and 10 g/L) with and without the immersion of a copper coupon. The results show that after the copper coupon standing in the electrolyte, there is a change in the absorbance maximum in the solution with 5 g/L RFLE, while no change is observed in the solution with 10 g/L RFLE. Such a change indicates the existence of a copper-RFLE complex in the solution with lower inhibitor concentration. In the case of RFLE, forming a copper complex with caffeic acid, isoquercetin and astragalin is possible. The absence of the complex at a concentration of 10 g/L RFLE can be attributed to a change in the mechanism and the lack of copper ions in the solution due to adequate corrosion protection.

This study investigates the kinetic models of Cu²⁺ ion adsorption onto clinoptilolite-rich zeolite. The study highlights the importance of diffusion kinetic models in understanding the adsorption process. The initial phases are significantly influenced by the ion diffusion through the film to the particle surface, particularly within the first 30 minutes, which is crucial for the heterogeneous surfaces like zeolites. Following this, the surface adsorption (intraparticle diffusion) is described by the Weber-Morris model, effective primarily during the initial stage. As the process progresses beyond 20-30 minutes, the ion removal rates decrease sharply, and diffusion within the particle core becomes the dominant factor, influencing the overall reaction rate.

Early orthodontic treatment is considered as treatment that begins and ends before all permanent teeth erupt, i.e. it is carried out in the period of milk and mixed dentition. Synonyms of early treatment are: preventive orthodontic treatment, interceptive orthodontic treatment or the first phase of comprehensive treatment. The aim of the work is to consider the advantages and disadvantages of early orthodontic therapy. It is necessary to carry out therapy that will lead to the desired facial aesthetics, increase the child's confidence, parents' satisfaction, enable simpler therapy in the future, a better and more stable result, enable the proper performance of orofacial functions, achieve more opportunities for skeletal growth modification and reduce potential iatrogenic damage. Based on an extensive diagnostic procedure, which includes: history, clinical examination, functional analysis, radiography and photography of the patient and analysis of study models, we come up with a therapy plan. The case report is a girl aged 9 years and 3 months. Early treatment should be carried out only in children who have a definite need for treatment. The group with a limited need should be given time for spontaneous correction.

Anemia is the most common disorder globally and one of the conditions that general practitioners most frequently encounter. The human erythrocytes are exposed to constant stress while they circulate in the blood (e.g. shear stress, osmotic stress, oxidative stress). The scope of this review was to analyze the literature data on what do the hormonal receptors do on mature red blood cells (RBC) and how they relate to the risk of anemia. We investigated the literature data in the last five years (PubMed, Google Schoolar) and analyzed the effects of hormonal receptors on four specific characteristics of mature erythrocytes: osmotic resistance; deformability/rheology, RBC hemoglobin affinity to oxygen and eryptosis. We found that the hormones have a strong impact in regulating erythrocyte survival and functionality. These receptors increase the physiological plasticity of mature erythrocytes and serve as the effective tool for deeper effects of integral regulatory mechanisms, that promote their survival and whole-body homeostasis. Additionally, these hormonal receptors are closely associated with the risk of anaemia: when the supportive function of hormones and their receptors is not effective, eryptosis increases and, consequently, the number of mature erythrocytes in the circulation decreases.

Red mud, byproduct of the aluminum industry, poses a significant environmental problem due to its chemical composition and the large quantities generated. This study explores the potential for its valorization through a multi-step process that includes reduction, leaching with acid solution, purification, and ultrasonic spray pyrolysis (USP). In the first step, red mud undergoes carbothermal reduction, during which metal oxides are transformed into metal phase and slag. In the second step, the slag is subjected to leaching under various conditions, including changes in pressure, temperature, and acid concentration, which allows the recovery of titanium in the form of titanium oxysulfate and other metals. Finally, after purifying the solution using precipitation or solvent extraction, ultrasonic spray pyrolysis is used to synthesize titanium dioxide (TiO₂) nanopowders from titanium oxysulfate (TiOSO₄). This integrated approach not only reduces waste but also produces high-value materials with broad industrial applications.

Properties of concrete containing the ground calcined low-kaolinite clay was experimentally studied. Clay, calcined at 900 and 1000°C, was used as a partial replacement of cement at dosage of 20 % by the weight of cement. Tests performed on concrete samples include the consistency, air content, compressive strength and flexural strength. The experimental results show a moderate decrease in slump, as well as in compressive and flexural strength comparing to concrete containing only cement CEM I as a binder. Better results were obtained with concrete containing clay calcined at 1000°C. Further research is needed to determine the optimal dosage of calcined clay in concrete, as well as the optimal temperature of clay calcination.

Introduction: Metacognition, which refers to the ability to oversee and regulate one's cognitive activities, plays a crucial role in medical education. Evaluating metacognitive awareness is particularly important for university students, as it impacts their learning strategies and academic performance. The objective of this study was to examine the psychometric characteristics of the Serbian adaptation of the Metacognitive Awareness Inventory (MAI), with an emphasis on its construct validity and internal consistency. Materials and methods: This was a cross-sectional study conducted at the Faculty of Medicine University of Belgrade, on third-year medical students during October 2024. The psychometric properties of the Serbian version of the MAI were evaluated by assessing its factorial structure and internal consistency. The MAI consists of 52 items, comprising two primary components: 'Knowledge of Cognition' and 'Regulation of Cognition'. The subcomponent of "knowledge of cognition" were categorized into declarative knowledge, procedural knowledge, and conditional knowledge, whereas "regulation of cognition" subcomponent were classified into planning, information management strategies, comprehension monitoring, debugging, and evaluation. Results: A total of 426 medical students were included in the study. The mean age of the respondents was 21.3 ± 1.4 years, and the majority were females (68.5%). The mean score of the scale was 199.0. The internal consistency analysis of the Serbian version of the MAI questionnaire yielded a Cronbach's a of 0.94, and a McDonald's o of 0.95 for the entire scale, which indicates excellent scale reliability. The Serbian version of the MAI questionnaire was validated using confirmatory factor analysis, supporting both the hypothesized eight-factor and two-factor structures. The eight-factor model showed good fit indices (IFI = 0.908, CFI = 0.905, RMSEA = 0.042), with statistically significant factor loadings (p < 0.05). Similarly, the two-factor model demonstrated adequate fit (IFI = 0.921, CFI = 0.918, RMSEA = 0.039), with all loadings also significant (p < 0.05). Conclusion: The present study revealed the Serbian version of MAI as reliable and valid tool for identifying medical students' metaconginive awareness.

This paper aims to compare the mechanical and structural properties of butt-welded properties of dissimilar aluminum alloys 2024-T351 and AA 6082-T6 obtained by MIG and TIG welding processes. Alloy AA 6082 T6 is well weldable by classic fusion welding processes (MIG and TIG), while alloy 2024-T351 is almost non-weldable. For the welding of these two different Al alloys, MIG and TIG welding procedures were used on 8 mm thick sheet metal using additional material 4043A (AlSi5) and a mixture of argon and helium as a protective gas for the MIG welding process, or pure argon for the TIG welding process. The paper compares the mechanical properties of welded joints obtained by MIG and TIG welding. The microstructural evolution of the welded joint of dissimilar aluminum alloys AA6082-T6 and AA2024-T351 is compared. The mechanical properties of welded joints of dissimilar aluminum alloys are compared based on the results of Vickers hardness tests, tensile and bending tests of welded samples.

Proper nutrition is important for the healthy growth and development of preschool children. During this period, they undergo rapid physical, cognitive, and emotional changes, making it essential to provide both the necessary nutrients to support their overall development and hygienically safe foods. Maintaining high sanitary and hygienic standards in preschool food facilities requires a comprehensive approach that integrates regulatory compliance, facility design, staff training, and effective sanitation practices. By prioritizing these standards, preschools can provide a safe and healthy environment that supports the well-being and development of preschool children. Regulatory requirements form the backbone of sanitation standards in preschools. These guidelines are often established by public health authorities and childcare regulators, setting out minimum standards for cleanliness, food handling, and facility maintenance. Adherence to these regulations ensures that preschools provide a safe and healthy environment for children. Essential components include proper kitchen design, adequate ventilation, pest control measures, and accessible handwashing facilities. Assessing the effectiveness of hygiene practices in preschools involves a multi-pronged approach, including regular inspections, health monitoring, feedback collection, staff training assessments, and incident analysis. By continuously evaluating and improving hygiene practices, preschools can provide a safe and healthy environment for children.