SOUTHERN JOURNAL OF SCIENCES

Background: The recovery of any valuable component from dolomite as a double carbonate mineral depends on its dissolution efficiency. Aim: This study aimed to optimize and provide a simplified novel approach to the kinetics of dolomite dissolution in sulphuric acid solution using the Box-Behnken experimental design. Methods: The dolomite sample was dissolved in a sulphuric acid solution at seventeen different experimental conditions. The residue containing impurities was removed via filtration, while precipitation was carried out at the optimum conditions. Results and Discussion: The relationship between the independent and dependent variables best fits into the two-factor interaction model with a coefficient of determination of 0.9492, adjusted R² of 0.9187, and predicted R² of 0.7514. The total residual sum of 3x10^-13 and adequate precision of 18.769 show that the predicted dissolution efficiency is much closer to the experimental values. The analysis of variance revealed that the individual effect of acid concentration, temperature, and dissolution time all positively contribute to the dissolution. The interactive effect of acid concentration with temperature and the interactive effect of temperature with dissolution time also positively influences the dissolution efficiency. Following the dissolution of dolomite in sulphuric acid, a white precipitate was formed at room temperature, which dissolved back at a temperature of 70 oC, agitation speed of 900 revolutions per minute, and within 10 minutes. A predictive approach using a two-factor interactive model was applied to generate the kinetic data. Conclusions: The established model equation is suitable for predicting dolomite dissolution in sulphuric acid. The application of the shrinking core model to the generated data shows that the reaction between dolomite and sulphuric acid is film diffusion control with a first-order reaction (0.6587) and activation energy of 27.5 KJmol-1k-1.

Background: Air pollution is one of the significant environmental challenges facing modern humanity. Atmospheric air is polluted with harmful substances emitted from anthropogenic and natural sources. Aim: The presented paper provides an overview of monitoring results conducted in the Capital of Georgia for 2023. Results from air quality monitoring sensors show that particulate matter, sulfur, and nitrogen dioxide represent problematic pollutants in different city areas. Methods: The research was carried out through sensors installed in different districts of Tbilisi. The investigation was carried out within the NATO SPS program project REACT. Results: Atmospheric air pollution was monitored at four stationary sensor sets on K. Cholokashvili, Nutsubidze Street, Chavchavadze Avenues, and the Old Tbilisi area. The results are presented in the article in the form of tables. Discussion: Average indexes of sulfur dioxide and PM particles were observed in all areas. Nitrogen dioxide indices were both low and medium. Conclusions: Based on the data obtained, it can be assumed that the air in most districts of Tbilisi is moderately polluted, and in some cases, the data exceeds the maximum allowable norm. There may be several reasons for this.: 1. Unauthorized slashing of Green islands and massive construction of high-rise residential buildings on their place in Tbilisi. 2. Malfunctioning vehicles, the technical inspection of which has recently been made stringent. However, some vehicles still pollute the air. 3. Emissions produced by mini factories and enterprises.

Background: Diabetes Type 2 is a complex disorder described by an imbalance between insulin resistance and secretion that induce liver glucose output. It has been shown that serum insulin levels are affected by a sperm plasma membrane and acrosome. Therefore, during insulin resistance spermatogenesis changes, diabetic patients detect testicular changes. Aims: This research aims to know the effect of diabetic type 2 on some aspects of fertility in men by studying the characteristics of the semen and some biochemical parameters in seminal plasma. Methods: This study was achieved at the Center for Endocrinology and Diabetes Specialists in Maysan province from February to November 2018 and included 45 men (30 diabetic and 15 healthy in the control group) aged 30 to 59 years. The patients were divided according to age into two groups, the first (30-39) and second (40-59) years, also divided by the duration of diabetes into two groups, the first (1-5) and second (6-10) year. Results: The pH of semen in the second age group (40-49 years) group and first duration (1-5 years) group were significantly decreased (P <0.05) in diabetes compared with the control group. Volume and viscosity did not have significant differences in patients compared to the control following the age and duration of diabetes. Liquefaction only in the first age (30-39 years) group significantly increased (P <0.05) compared to the control. The concentration of sperm, progressive motility, non-progressive and normal morphology decreased (P <0.05) significantly. While the sluggish, dead, and abnormal morphology significantly increased (P <0.05) in all diabetes groups compared with the control. The fructose and alkaline phosphatase values in the seminal plasma were not differing significantly in patients compared with the control. Zinc and glutathione values decreased significantly (P <0.05) compared with control in each age and duration of diabetes. Discussion: Insulin stimulates the Ledying cell function, defect insulin effect on spermatogenesis. Impaired sperm motility in a patient with D.M. might be attributed to many reasons, such as increased ROS level, altered mitochondria DNA, and decreased epididymal products. Conclusion: our measurement indicates that there is an effect of type 2 diabetes mellitus on semen parameters and seminal plasma biochemical parameters.