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Due to the necessity of performing thermal operations, heat exchangers are widely employed in many different areas. The heat transfer and fluid flow within a spiral double-pipe heat exchanger fitted with a novel turbulator were numerically assessed in this work. The presented novel turbulator is a curved tube with holes incorporated into its thickness and spiral ribs on its inner wall. The turbulator wall's curved rib design produces secondary flows at the turbulator output when fluid flows through the tube and the perforations. A commercial CFD tool, based on the finite volume technique, was used to conduct the numerical simulations. The fluid flow regime is turbulence (Re = 8,000 – 14,000). Two sections make up this work. The first portion looked at how the hydrothermal behavior of the fluid flow inside the proposed turbulator was affected by the angle at which the curved ribs rotated. For this angle, three values were considered: θ = 30, 90, and 150°, and the outcomes were contrasted with those of a plain spiral double-tube heat exchanger (turbulator not included). Then, the number of embedded holes in the turbulator's thickness changes in the second part, and three values of N= 12, 16, and 20 were considered. According to the first part's findings, the model exhibiting θ = 90° had a greater thermal performance factor at Re = 10,000. This model has a more noteworthy thermal performance factor than the models with θ = 150 and θ = 30° by approximately 15.62 % and 22.65 %, respectively (at Re = 10,000). Furthermore, the second section's numerical findings showed that the model with N= 20 had more extraordinary thermal performance at Re = 10,000. Model N= 20 has a thermal performance factor of about 16.93 % and 17.55 % greater than models N= 16 and N= 12. Within the proposed heat exchanger, the recommended turbulator produced a sizable rotating flow, and including embedded holes significantly reduced the pressure drop this kind of turbulator causes.

The development of economic and environmentally friendly extractants to recover cobalt metal is required due to the increasing demand for this metal. In this study, solvent extraction of Co(II) from aqueous solution using a mixture of N,N′-carbonyl difatty amides (CDFAs) synthesised from palm oil as the extractant was carried out. The effects of various parameters such as acid, contact time, extractant concentration, metal ion concentration and stripping agent and the separation of Co(II) from other metal ions such as Fe(II), Ni(II), Zn(III) and Cd(II) were investigated. It was found that the extraction of Co(II) into the organic phase involved the formation of 1:1 complexes. Co(II) was successfully separated from commonly associated metal ions such as Fe(II), Ni(II), Zn(III) and Cd(II). Co(II) stripping from the loaded organic phase was studied in aqueous solution. These results are useful to recover Co(II) from aqueous solution utilising (CDFAs) as an extractant.

Background: Coronavirus disease 2019 (COVID-19) is a pandemic caused by a newly discovered coronavirus. Although clinical manifestations of COVID-19 are mainly pulmonary, some patients have other systemic manifestations. This study aimed to describe the clinical finding and outcomes in Sudanese patients diagnosed with COVID-19. Methods: This retrospective observational study is based on documented files that included patients diagnosed with COVID-19 in seven selected hospitals inside Khartoum. Clinical manifestations, complications and outcomes were extracted from patients’ records using an extraction form designed for this study. Results: Data of 243 patients diagnosed with COVID-19 were analyzed. The mean (SD) age in years was 55.8 (18.4). Out of 116 participants, 27 of them (23.3%) had severe disease, 15 (12.9%) were critically ill. 67.5% of patients were admitted to the hospital within 7 days from onset of symptoms; most of them were admitted to the wards (n= 140,72.5%). Fever (83.2%), cough (70.7%), and shortness of breath (69.2%) were the most commonly recorded clinical manifestations. Sepsis (9.8%) and acidosis (7.8%) were the most frequently reported complications. Death was the final outcome in 21.4% (56/243). Older age and presence of diabetes were found significantly associated with in-hospital death. The laboratory results showed high CRP in 85.6% (119/139), high ferritin in 88.9% (24/27), lactate dehydrogenase had a median of 409.0 (359–760), D-dimer had a median of 3.3 (1.2–16. 6), and 53/105 (50.5%) had low albumin. Conclusions: Fever was the most mentioned sign among the participants, followed by fatigue. Cough and shortness of breath were the most commonly recorded pulmonary symptoms manifested. Our study showed multiple variables were associated with in-hospital death. The mortality rate was high among severe and critically ill patients diagnosed with COVID-19.