A numerical investigation has been performed to study the effect of eccentricity on unsteady state, laminar aiding mixed convection in a horizontal concentric and eccentric cylindrical annulus. The outer cylinder was kept at a constant temperature
while the inner cylinder was heated with constant heat flux. The study involved numerical solution of transient momentum (Navier-Stokes) and energy equation using finite difference method (FDM), where the body fitted coordinate system (BFC) was
used to generate the grid mesh for computational plane. The governing equations were transformed to the vorticity-stream function formula as for momentum equations and to the temperature and stream function for energy equation.
A computer program (Fortran 90) was built to calculate the bulk Nusselt number (Nub) after reaching steady state condition for fluid Prandtl number fixed at 0.7 (air) with radius ratio ( =2.6), Rayleigh number (Ra=200), Reynolds number (Re=50) for both concentric and eccentric cylindrical annulus with different eccentricity ratios (ε=0, 0.25, 0.50, 0.75) and angular positions (φo=0o
, 45o , 90o , 135o , 180o ).
The results show a reasonable representation to the relation between Nusselt number and (ε, φo). Generally, Nub decreased with the increase in (ε and φo). Also, results show that the best thermal performance for the inner cylinder was at the angular
position (φo=0o ) for eccentricity ratio (ε=0.25), while the maximum reduction in the rate of heat transfer for the inner cylinder was at the angular position (φo=180o) for eccentricity ratio (ε=0.75).
Comparison of the result with the previous work shows a good agreement.
A Schiff base ligand (L) was synthesized via condensation of N-( 1-naphthyl) ethylenediamine dihydrochloride with phthalaldehyde. The ligand was characterized by FT-IR, UV–Vis, 1H NMR, mass spectrometry, and elemental analysis (C, H, N). Five metal complexes (Co(II), Ni(II), Cu(II), Zn(II), and Cd(II)) were prepared with the ligand in a 1:1 (M:L) ratio using an aqueous ethanol solution. The complexes were characterized by FT-IR, UV–Vis, mass spectrometry, and elemental analysis (C, H, N). Additionally, 1H NMR spectroscopy was employed for Cd(II) complex. Antimicrobial activity of the ligand and its metal complexes against pathogenic bacteria (K. pneumoniae, E. coli, S. aureus, and S. epidermidis) and fungus (C. albicans) were evaluated
... Show MoreA Schiff base ligand (L) was synthesized via condensation of
This research aimed to explore the use of foamed concrete (FC), a lightweight concrete, by replacing sand with crushed plastic from washing machines to improve environmental and thermal properties. The primary components included traditional materials like cement, water, and a foaming agent, along with the innovative use of waste plastic (WP). Utilizing Minitab software, the study applied the Response Surface Method to optimize mix designs, reducing the experimental mixtures to 31, which were then tested for dry density, porosity, water absorption, shrinkage, compressive strength, splitting tensile strength, and thermal conductivity. Results indicated a significant 24% reduction in dry density when using plastic as fine and coarse aggregate
... Show MoreObjective: This study involved the synthesis of new Schiff bases and 1,3-oxazepine derivatives from the baclofen drug and study the anticancer activities. Methods: Baclofen was initially reacted with aromatic aldehydes to create Schiff base derivatives (Ia–Ib), which were then closed in the next step using anhydrous acids to form oxazepine derivatives (IIa–IId). Results: The title compounds were synthesized successfully and identified using FT-IR, 1H NMR, and 13C NMR spectroscopy. Additionally, compound (IIc)’s (3-(4-chloro-phenyl)-4-[2-(4nitro-phenyl)-4,7-dioxo-4,7-dihydro-[1,3] oxazepin-3-yl]butyric acid) anticancer activity was assessed using MTT assay against FTC-133 (thyroid cancer) compared with WRL-68 (normal cell line). Discus
... Show MoreThis study was aimed to assess the impact of vermicompost, glutathione, and their interaction on beetroot (Beta vulgaris L.) growth, yield, and antioxidant traits. The experiment carried out at vegetable field of the College of Agricultural Engineering Sciences - University of Baghdad during fall season 2019. The experiment was conducted using factorial arrangement within Randomized Complete Block Design with two factors and three replicates (3X3X3). Applying vermicompost before cultivation represented the first factor (0, 15, 30 ton.ha-1), which symbolized (V0, V1, V2). Glutathione (0, 75, 150 mg.L-1) which symbolized (G0, G1, G2) represented the second factor. Results showed the superiority of secondary interaction treatment V2G2
... Show MoreHeterocyclic compounds are crucial for medicinal chemistry and the development of therapeutic agents like broad-spectrum antibiotics. This study devised a facile procedure to synthesize novel antimicrobial bicyclic heterocycles from 2-mercapto-3-phenylquinazolin-4(3H)-one. Advanced analytical techniques including 1 H and 13C NMR, elemental analysis, and FT-IR spectroscopy characterized the intricate chemical structures of the products. In vitro assays tested the heterocycles against aerobic and anaerobic bacterial strains using fluconazole and ciprofloxacin as antifungal and antibacterial controls. Results demonstrated the formidable broad-spectrum antibacterial and antifungal activities of the synthesized compounds, with growth inhibition
... Show MoreThe human stomach is home to the Gram-negative bacterium Helicobacter pylori, which has been connected to several gastrointestinal disorders. There may be a link between H. pylori infection and the start of autoimmune disorders, according to recent research. This review examines the intricate connections between persistent H. pylori infection, immune system dysregulation, and their possible role in initiating autoimmune disorders. The study begins with a summary of H. pylori infection and its prevalence worldwide, emphasizing the mounting data that connects this bacterium to autoimmune disorders. Then, using experimental data from animal models and epidemiological research as support, it undertakes a thorough review of autoimmune di
... Show MoreA Schiff base ligand (L) was synthesized via condensation of
Background/Objectives: Nonsurgical periodontal treatment (NSPT) is the gold-standard technique for treating periodontitis. However, an individual’s susceptibility or the inadequate removal of subgingival biofilms could lead to unfavorable responses to NSPT. This study aimed to assess the potential of salivary and microbiological biomarkers in predicting the site-specific and whole-mouth outcomes of NSPT. Methods: A total of 68 periodontitis patients exhibiting 1111 periodontal pockets 4 to 6 mm in depth completed the active phase of periodontal treatment. Clinical periodontal parameters, saliva, and subgingival biofilm samples were collected from each patient at baseline and three months after NSPT. A quantitative PCR assay was us
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