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.
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.
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.
TIG welding is used when a good weld appearance and a highest quality of the weld are required Nevertheless, the process has also some major disadvantages like relatively shallow penetration capability and low productivity. To increase the penetration and/or productivity, instead of traditional pure Ar, gas mixtures containing gases with high thermal conduction can be used. For austenitic stainless steels, as they are not prone to hydrogen cracking, also H2 is suitable. As H2 is active gas, the process is called Tungsten Active Gas (TAG). In this research, austenitic stainless steel sheet was welded with a competitive welding speed of 40 cm min−1, with pure argon and with Ar+7.5 H2 mixture. With pure Ar, a welding current of 220 A was far too small to reach full penetration in 3 mm sheet. With the 7.5 H2 active gas mixture, only 130 A was sufficient with unchanged welding speed.
Background: Degenerative aortic stenosis is a prevalent and severe condition necessitating aortic valve replacement (AVR) when the valve area critically narrows to 0.7 cm² or when symptoms are manifested. Traditional AVR via median sternotomy, poses considerable risks for patients with comorbidities or advanced age. Objective: This study evaluates the efficacy and safety of mini sternotomy aortic valve replacement (MSAVR), a minimally invasive technique designed to reduce surgical trauma, improve postoperative recovery, and lower healthcare costs. Methods: A reversed L-type upper partial sternotomy (RLUPS) approach was performed in five patients focusing on standardized surgical procedures, and rigorous postoperative care. Key findings indicate that MSAVR markedly reduces postoperative complications, ICU stay, and overall hospital stay compared to traditional sternotomy. Results: The median postoperative length of stay was seven days for MSAVR versus 12 days for traditional sternotomy, with ICU stays of 52 hours and 119 hours, respectively. Our study also highlights the cost-effectiveness of MSAVR, with decreased hospital costs per patient due to reduced ICU resource utilization and shorter hospital stays. These findings suggest that MSAVR is a valuable and advantageous alternative to traditional sternotomy, offering substantial benefits in terms of patient outcomes and healthcare efficiency. Conclusion: Our work underscores the potential of minimally invasive techniques in improving the management of severe degenerative aortic stenosis, marking a significant advancement in the field of cardiac surgery.
The first industrial robots appeared in the production processes of the 60s of the last century, and they are implemented to this day in all production processes in the world. The biggest application of industrial robots has been found in three industries in the world: the automotive industry, the electrical/electronic industry and the metal industry. The automotive industry is the first to implement the most industrial robots, and in recent years the electrical/electronics industry has also joined in, as these two industries in the world implement more than 60% of the total industrial robots implemented in the world. The use of industrial robots has been used to perform those tasks that are tiring and hazardous to the health of workers, which include welding, and the performance of these operations is mostly n the automotive industry. To date, the most implemented industrial robots of the first generation, which are robustly surrounded by fences (for the protection of workers), take up a lot of space and are complicated to reprogram. Development of new technologies such as: sensor technology, Internet of Things (IoT), big data, „cloud computing“, virtual and augmented reality (AR), artificial intelligence (AI), advanced security systems and others is credited with the development of robotic technology. In this paper is shown the trend of implementing industrial robots and their role in the welding process.
This study aims to identify the cybersecurity awareness of university students from Bosnia and Herzegovina, Serbia, and Montenegro in the following aspects: a) Malware, b) Password usage, c) Phishing, d) Social engineering, and e) Online scams. A quantitative-qualitative research approach was used. Data for the quantitative section were collected using the Cyber Security Behaviour Instrument questionnaire (Muniandy et al., 2017). In the qualitative section, five semi-structured interviews were conducted with students about their behaviour and protection on the internet. Research has shown that respondents apply some good, but still also some weak or dangerous cybersecurity practices in above mentioned aspects. That confirms that the human element remains a critical vulnerability for individuals, businesses, and societies facing rapidly evolving online threats, and that we urgently need the improvement of personal cyber hygiene. The findings highlight strengths and weaknesses in respondents’ knowledge and behaviours related to cybersecurity, underscoring the need for continuous education and awareness-raising to improve internet security practices.
Multi-purpose reservoir Modrac is the most important water resource in Tuzla canton( northeastern Bosnia and Herzegovina). Ecologically acceptable flow on dam Modrac is not adjusted with the latest Rulebook about methods of determining ecologically acceptable flow. Modrac reservoir with upstream and downstream flow of Spreca river is categorized as a protected water resource due to its susceptibility to eutrophication and according to current legislation, requires a second level of ecologically acceptable flow assessment. This paper shows the methods used to determine ecologically acceptable flow on the Modrac dam, respecting the fact that reservoir Modrac is declared as protected water resource. The given calculation of ecologically acceptable flow is made for II level of evaluation
In this paper, the results of measurements of indoor radon activity concentration in fourteen elementary schools in Tuzla, Bosnia and Herzegovina, are presented. Measurements were performed with CR-39 solid-state nuclear track detectors. Radon activity concentration in investigated locations was 6.8-143 Bqm-3. To assess the indoor radon hazards for people, the annual effective dose, excess lifetime cancer risk, and the relative risk of lung cancer were estimated.
Background: Non-surgical periodontal therapy, including mechanical debridement and root planning, is the gold standard in the treatment of periodontal diseases. The most commonly used instruments for non-surgical therapy are sonic/ultrasonic devices and manual instruments such as curettes. Objective: This study evaluates the clinical effectiveness and patient experience of non-surgical periodontal therapy using the Vector® Paro Pro ultrasonic device, emphasizing its impact on periodontal indices and patient comfort. Methods: Fifty patients with gingivitis, periodontitis, or peri-implantitis participated. Baseline data, including Plaque Index (PI), Gingival Index (GI), Papillary Bleeding Index (PBI), Probing Depth (PD), and Clinical Attachment Loss (CAL), were recorded. Patients underwent treatment using the Vector® Paro Pro system. Evaluations were conducted at baseline, two weeks, and one month post-therapy. Statistical analyses utilized repeated measures ANOVA and paired t-tests, with a significance threshold of p<0.05. Patient experience was assessed via a questionnaire. Results: All periodontal indices showed significant improvement post-therapy. The mean PI decreased from 1.18±0.12 to 0.52±0.08 after two weeks and 0.44±0.09 after one month (p<0.001). Significant reductions were observed in PBI (from 1.68±0.10 to 0.46±0.09) and PD (>4 mm pockets: from 5.55±0.19 to 3.65±0.45; p<0.001). CAL improved significantly (from 0.80±0.18 to 0.70±0.16 after one month; p<0.001). Patient-reported outcomes revealed that 98% experienced no pain during therapy. Conclusion: The Vector® Paro Pro ultrasonic device demonstrated significant clinical improvements in periodontal health, particularly in bleeding reduction and deep pocket management. Its hydroxyapatite-enhanced fluid effectively polished root surfaces and reduced post-therapeutic sensitivity. Patients reported minimal discomfort, underscoring the device’s potential as a comfortable, efficient alternative for non-surgical periodontal therapy. Further studies with longer follow-up periods are recommended to confirm these findings.
Background: As a surgical nurse in a healthcare team, it is helpful to position the patient, depending on the nature of the procedure, and to prepare independently both the instrumentation and the site of surgery with drapes prior to the surgical procedure. Objective: To examine the experience of surgical nurses in their work with the WHO surgical checklist in Sweden. Methods: Data were collected from one hundred and ninety-six healthcare professionals, including thirty-nine surgical nurses, using a self-administered questionnaire. The Mantel-Haenszel and Pearson χ2 tests were used for ordered and unordered categorical variables. The qualitative data was presented in the form of the positive and negative contribution of the checklist and the text was analyzed according to Graneheim and Lundman. Results: Surgical nurses (61.6%) answered “no” to the question about being educated and trained in using checklists. Almost the same answer was given when it came to adapting the checklist to the department and the fact that the assistant nurse was responsible for ensuring the checklist was used (61.5%). 89.9% of them did not know who was responsible for implementing the checklist before surgery. According to (56.4%), the checklist was used all the time in emergencies, while (12.8%) of them stated that they did not believe that the checklist improved patient safety. Conclusions: Compliance with the WHO’s checklist varies, and the observed compliance is lower than that documented. The surgical nurses gave the same responses as others in the team. Clearer procedures are needed during surgery, specifying how the checklist should be used in practice, and there should be a designated person who is responsible for implementing the checklist.
One of the most often used welding processes for unalloyed structural steels is MAG, which is relatively simple, yet achieving high deposition rates. On the other side, there are standards describing weld quality based on weld geometry. This paper describes influence of heat input on weld geometry for MAG fillet welds of unalloyed steel with thicknesses of 8 mm, in horizontal and overhead position. Independently varied parameters were welding current and speed. Influence is described through models based on linear regression analysis. Comparison is made between models developed for different positions, as well as with those available in literature.
Background: Tuberous Sclerosis Complex (TSC) is an autosomal dominant genetic disorder and involves multiple organs, intellectual disability and epilepsy. Mutations in TSC1 and TSC2 genes are responsible for the molecular disease mechanism. Objective: The aim is to determine molecular background of a patient with a suspicion of TSC. Case presentation: In this case report, we describe a seven year old patient with the clinical manifestation of TSC that includes supratentorial changes, subependymal hamartomas and angifibromas in the facial area. Besides the brain and skin changes, no other TSC characteristics were observed. The patient was referred to molecular genetic testing using Next Generation Sequencing (NGS). Results: Clinical exome sequencing revealed intronic TSC2 c.4849+2T>G variant. The variant was confirmed using Sanger sequencing on the subject. However, the variant was not detected in the parents, which indicated that it arose de-novo. The RegSNP-intron, Mutation Taster and Human Splicing Finder were used as a bioinformatic tools to predict the possible effect on protein. Using bioinformatic tools, it was determined that the variant is possibly damaging to protein. Conclusion: This data suggest that observed splicing intronic variant could be the cause of TSC in this pediatric patient.
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