SOUTHERN JOURNAL OF SCIENCES

Background: In line with the current global energy crisis, there is an urgent need to seek cheap energy sources. This study has utilized waste materials for synthesizing biodiesel, an environmentally friendly alternative energy. Aim: This study aimed to prepare low-cost carbon-based zirconium impregnated heterogeneous catalysts using wood dust to produce biodiesel from waste vegetable oil (WVO). Methods: Response Surface Methodology via Central Composite Design (RSM-CCD) optimized the biodiesel production process. The physico-chemical properties of waste vegetable methyl ester were determined following the American Standard Testing of Materials (ASTM). In addition, the catalyst morphology and elemental composition were determined using Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray (EDX), respectively. Results and Discussion: The optimum conditions were observed to be 8:1 methanol/oil ratio, 5 wt% catalyst loading, 55 °C temperature, and 3 hours of reaction time. The corresponding response was observed to be 98.39%. Conclusions: The experimental analysis confirmed that the synthesized catalyst from wood dust under optimized conditions transesterified the waste vegetable oil into biodiesel with properties that comply with American Standard Testing of Materials.

Escherichia coli (E. coli) is the most common type of pathogen that causes Urinary tract infection disease. It can be presented as a pathogenic or non-pathogenic strain and found not only in the animal but also in the human intestine. This bacterium can cause opportunistic infection when the human host comprised of thalassemia patients or changes the healthy hemostatic flora. This study aimed to analyze the presence of bacteria in thalassemia patients with urinary tract infection. A total of 303 samples were collected during the period from August 2019 to January 2020 from thalassemia patients who suffered from urinary tract infection. The results showed that there were 6.9% of patients infected with E. coli, 2.6% of patients were infected with S. aureus, 0.7% with both Proteus and Klebsiella, while 89.1% of patients had a negative sample for bacteria. Also, the incidence of urinary tract infections in females is higher than in males. Besides, its occurrence in rural areas is higher than in city residents. Moreover, among 16 antibiotics tested to sensitize bacteria to antibiotics, Imipenem showed 100% efficacy on all isolated bacteria. In contrast, Netilmicin showed 80.1% efficacy, Gentamycin 80.1%, and Amikacin 76.2%. Ampicillin, Aztreonam, Amoxicillin-Clavulanic Acid, Tetracycline, and Ticarcillin-Clavulanic Acid, did not show any effectiveness toward the bacteria while other antibiotics showed different activities. Furthermore, the isolated microbes from thalassemia patients were the highest resistance to antibiotics in comparison with other studies, and this antibiotic-resistant may be due to the weakening of the patient's immune status and frequent blood taking and the antibodies it contains.

Dentistry is a part of medicine, where various polymer materials were used for the first time. Many factors forced researchers to find more stable, versatile, and hygienic materials for the manufacture of dental products. It is important to note that the search for the ideal polymer dental material is still ongoing. This is because modern polymers, in some cases, do not meet the specified requirements for chemical, physical, strength, and elasticproperties. Based on the data on the method of creating and using silicone material for the base of the removable prosthesis "Gossil", an improved silicone material for two-layer dentures "Silep" was developed, as well as a special primer for better connection of the lining with the rigid acrylic base of the prosthesis. To evaluate the most suitable compound, materials were tested for several parameters, such as tensile strength, elongation, and shore hardness. In addition to selecting a suitable material for modification, the selection and testing of an adhesive that allows the chemical bonding of the acrylate surface to the siloxane surface were carried out.