In this study NiO - CoO bimetallic catalysts are prepared with two Ni/Co ratios (70:30 and 80: 20) using the precipitation method of nitrate salts. The effects of Ni /Co ratio and preparation methods on the catalyst are analyzed by using different characterization techniques, i.e. atomic absorption (AA) , XRD, surface area and pore volume measurements according to the BET method . The results indicate that the best catalyst is the one containing the percentage of Ni :Co ( 70 : 30 ). Experiments indicate that the optimal conditions to prepare catalyst are stirring for three hours at a temperature of 60oC of the preparation , pH= (8-9) , calcination temperature at 400oC for two hours using the impregnation method . The catalyst activity is studied through the application in the process of oxidative desulfurization of gas oil fuel . The optimal conditions for deep oxidative desulfurization processes are : catalysts 3% , 2 gm. Na2 CO3 , refluxe time 3 hours at 400 C , using a mechanical stirrer at moderate speed (700 rpm), the volume ratio of gas oil : H2O2 : acetic acid is 10: 1: 0.5 and extracted with 1:1 ratio of acetonitrile to the gas oil for three times . The results indicate that the catalysts are efficient to remove sulfur from gas oil depending on temperature, time, concentration of hydrogen peroxide H2O2 30 % and solvent used for extraction. The efficiency of the best catalyst gives a maximum sulfur removal reaching 68.97%.
Beta-lactamase was purified from local isolate Klebsiella pneumonia by several steps included precipitation with ammonium sulphate at 20-40% saturation, DEAE- ion exchange chromatography and gel filtration on Sephacryl S-200 column. The obtained purification fold and recovery were 32.66; 47.04% respectively. The characterization of the purified beta-lactamase showed that the molecular weight was about 4000 daltons as determined by gel filtration.Purified enzyme had an optimal pH of 7 for activity and an optimal stability between pH 6.5-7.5, results shows that the optimal temperature appear to be 35 ? C .During storage the enzyme retained 72% at -20 ? C and retained 25% of the activity at the same period at 4 ? C.
Leucine amino peptidases (LAP; EC 3.4.11.1) constitute a diverse set of exopeptidases that catalyze the hydrolysis of leucine residues from the amino-terminal of protein or peptide substrates, (LAP) are present in animals, plants, and microbes. In this study, leucine amino peptidase was purified partial from Arachis hypogaea seeds by using gel filtration chromatography Sephadex G-100. The enzyme was purified 3.965 fold with a recovery of 29.4%. Its pH and temperature optimum were(8.7) and (37oC), respectively. The results show novel properties of LAP from Arachis hypogaea L. or peanut. The Km value for LAP (77 mM), with V max (1538 m mole min-1). We recommend a separate isoenzymeof the enzyme (LAP) from Arachis hypogaea on L. peanut seeds a
... Show MoreBackground: The Streptococcus genus are the predominant bacteria in the mouth and the Streptococcus sanguinis is one of them which performing a primary function for expansion of dental biofilm. Gingival and periodontal disorders are caused by dental biofilm, today, there is a necessity to discover naturally presenting antibacterial compounds from herbs with less side effects as a substitutive to the commonly handled chlorohexidine. Thus, the purpose of this study was to assess the antibacterial activity of thymus vulgaris oil on Streptococcus sanguinis bacteria In vitro. Materials and Methods: Human supragingival plaque samples were taken from 10 subjects, then morphological and microscopical examination, bioch
... Show MoreOften there is no well drilling without problems. The solution lies in managing and evaluating these problems and developing strategies to manage and scale them. Non-productive time (NPT) is one of the main causes of delayed drilling operations. Many events or possibilities can lead to a halt in drilling operations or a marginal decrease in the advancement of drilling, this is called (NPT). Reducing NPT has an important impact on the total expenditure, time and cost are considered one of the most important success factors in the oil industry. In other words, steps must be taken to investigate and eliminate loss of time, that is, unproductive time in the drilling rig in order to save time and cost and reduce wasted time. The data of
... Show MoreBackground: Gallstone disease (GSD) is a significant global health burden with variable prevalence influenced by metabolic, genetic, and infectious factors. Increasing evidence suggests that Gram-positive bacteria, particularly Staphylococcus aureus and Enterococcus species, contribute to gallstone pathogenesis through enzymatic activity and biofilm formation. Objectives: To characterize Gram-positive bacteria within gallstones from Iraqi patients, evaluate their biofilm-forming capacity, and analyze the relationship between bacterial colonization, gallstone type, and cholesterol levels. Methods: A total of 100 gallstones were obtained from patients undergoing elective cholecystectomy between October 2024 and March 2025. Stones were
... Show MoreLuffa aegyptiaca is a plant of multi-purpose importance whose usefulness cuts across virtually all areas of life. This study has characterized L. aegyptiaca in Lagos state and determined the mineral, proximate, phytochemical as well as the heavy metal accumulation potential. Samples were collected from the 20 Local Government Areas (LGAs) in Lagos state at 2 samples per location. Genetic similarity and intra-specific variation in 40 samples of L. aegyptiaca were determined using 3 Random Amplified Polymorphic DNA (RAPD) primers which yielded a total of 42 markers of which 25 was polymorphic. The maximum number of bands (14) was produced by OPC4 while the minimum (7) were produced by OPAF20. Percenta
... Show MoreLet A ⊆ V(H) of any graph H, every node w of H be labeled using a set of numbers; , where d(w,v) denotes the distance between node w and the node v in H, known as its open A-distance pattern. A graph H is known as the open distance-pattern uniform (odpu)-graph, if there is a nonempty subset A ⊆V(H) together with is the same for all . Here is known as the open distance pattern uniform (odpu-) labeling of the graph H and A is known as an odpu-set of H. The minimum cardinality of vertices in any odpu-set of H, if it exists, will be known as the odpu-number of the graph H. This article gives a characterization of maximal outerplanar-odpu graphs. Also, it establishes that the possible odpu-number of an odpu-maximal outerplanar graph i
... Show MoreThis research paper aimed to quantitively characterize the pore structure of shale reservoirs. Six samples of Silurian shale from the Ahnet basin were selected for nitrogen adsorption-desorption analysis. Experimental findings showed that all the samples are mainly composed of mesopores with slit-like shaped pores, as well as the Barrett-Joyner-Halenda pore volume ranging from 0.014 to 0.046 cm3/ 100 g, where the lowest value has recorded in the AHTT-1 sample, whereas the highest one in AHTT-6, while the rest samples (AHTT-2, AHTT-3, AHTT-4, AHTT-5) have a similar average value of 0.03 cm3/ 100 g. Meanwhile, the surface area and pore size distribution were in the range of 3.8 to 11.1 m2 / g and 1.7 to 40 nm, respectively.
... Show MoreThe CdS quantum dots were prepared by chemical reaction
of cadmium oleylamine (Cd –oleylamine complex) with the
sulfite-oleylamine (S-oleylamine) with 1:6 mole ratios. The
optical properties structure and spectroscopy of the product
quantum dot were studied. The results show the dependence of the
optical properties on the crystal dimension and the formation of
the trap states in the energy band gap.