This study evaluates the efficacy of pullulan, a bacterial polysaccharide extracted from a local Micrococcus luteus isolate, in preserving the oxidative stability of unrefined sunflower oil. Using peroxide value (PV) and thiobarbituric acid value (TBA) as metrics. Five treatments were compared against a traditional antioxidant, butylated hydroxytoluene (BHT), and a control. Results demonstrated that the use of 800 ppm pullulan significantly inhibited oxidative degradation of the unrefined sunflower oil, particularly at 20°C storage. Peroxide values for 800 ppm pullulan (1.91 mEq.kg-1 at 20°C; 2.88 mEq.kg-1 at 50°C) were slightly higher than BHT (1.82 and 1.99 mEq.kg-1) but markedly lower than the control (4.49 and 3.59 mEq.kg-1).
... Show MoreThis study aims to prepare new compounds and investigate them spectroscopically and biologically against selected types of positive and negative bacteria and fungi to demonstrate their biological effectiveness. The prepared ligand combining formaldehyde, indole, sulfa benzamide, and 2-mercapto benzimidazole, a Mannich base ligand (L) was synthesized. The six metal ions including Cobalt (II), Nickel (II), Copper (II), Palladium (II), Platinum (IV), and gold (III) have interacted with the ligand and formed new complexes. Different spectroscopic methods, including C.H.N.S., FTIR, UV- Range visible, 1HNMR, 13CNMR, mass spectra, magnetic moment, and molar conductivity were used to suggest the new geometry of the complexes. The resul
... Show MoreFour metal complexes of Schi base ligand were prepared. To characterize both the ligand and the metal complexes, various techniques were employed, including elemental analysis, FT-IR spectroscopy, UV-Vis spectroscopy, molar conductivity measurements, magnetic moment determination, melting point, mass spectroscopy, 1H-NMR and 13C-NMR spectroscopy. The results showed that the metal complexes formed have the formula [M(L)2Cl2]Cl(n).H2O, where LD Schi base ligand and MDCr(III), Rh(III), Pt(IV) and Au(III), n D 1, 2. Based on spectroscopic analysis, coordination with metal ions involves the ’N’ donor atom of N atoms of the imine and the N-H amid group, and four complexes are suggested to have a six-coordinated octahedral structure. Molar c
... Show MoreThe azo ligand obtained from the diazotization reaction of 2-aminobenzothiazole and 4- nitroaniline yielded a novel series of complexes with Co(II), Ni(II), Cu(II), and Zn(II) ions. The complexes were investigated using spectral techniques such as UV-Vis, FT-IR, 1H and 13C NMR spectroscopic analyses, LC-MS and atomic absorption spectrometry, electrical conductivity, and magnetic susceptibility. The molar ratio of the synthesized compounds was determined using the ligand exchange ratio, which revealed the metal-ligand ratios in the isolated complexes were 1:2. The synthesized complexes were tested for antimicrobial activity against S. aureus, E. coli, C. albicans, and C. tropicalis bacterial species. Additionally, their binding affinities we
... Show Moreantimicrobial solutions against Coliforms, E. coli O157: H7, yeasts and molds were evaluated by agar well diffusion method. Chitosan (CH) exhibited best antimicrobial activity against the treated microorganisms at concentration of (5%) with contact time for 6hrs at refrigeration temperature (4ÚC), zones of inhibition for (GA) and (CH) for each solution alone ranging from (0 to 10 mm), chitosan solution (CH) exhibited both antibacterial and antifungal activities, Gum Arabic washing solution showed significant antibacterial activity (P < 0.05) against the microorganisms at concentration (15%), without inhibitory effect against E. coli O157:H7 at concentration (10%), in the current study the results confirmed that (15%) (w/v) of GA and 5%
... Show MoreIn the present work effect of recycled heating and cooling on the values of concrete compressive strength due to high temperature of 4000C was studied.
The tests show that the percent of reduction in compressive strength of the samples which exposed to a temperature of 4000C for one cycle was 32.5%, while the reduction was 52.7% for the samples which were exposed to recycled heating and cooling of ten times .
Moreover a study of the effect of specimen sizes on the percentages of compressive strength reduction due to high temperature
... Show MorePhase change materials are known to be good in use in latent heat thermal energy storage (LHTES) systems, but one of their drawbacks is the slow melting and solidification processes. So that, in this work, enhancing heat transfer of phase change material is studied experimentally for in charging and discharging processes by the addition of high thermal conductive material such as copper in the form of brushes, which were added in both PCM and air sides. The additions of brushes have been carried out with different void fractions (97%, 94% and 90%) and the effect of four different air velocities was tested. The results indicate that the minimum brush void fraction gave the maximum heat transfer in PCM and reduced the time
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