Now showing 1 - 5 of 60
- ItemTwo – Scale – Factor Universality of Binary Liquid Critical Mixture(2015-04-21) Ata, Balsam NaderThe dynamic shear viscosity of a binary liquid mixture phenol – water has been measured at different temperatures and concentrations. The critical temperature Tc and critical concentration xC_are found to be 67.0℃ and 33.90% by weight of phenol respectively, the critical density ρc is measured to be 0.8952 gm/cm3.The critical and background amplitudes of specific heat at constant pressure are calculated to be 78.117 J/kg.K and 85.292 J/kg.K respectively. The pressure derivative of the critical temperature along the critical line Tc′ is calculated to be 9.722 ×10-6 K/Pa. The dynamic shear viscosity of binary liquid mixture phenol – cyclohexane has been measured at different temperatures and concentrations. The critical temperature Tc and critical concentration xC are found to be 17.0℃ and 2.70% by weight of phenol respectively. The critical density ρc is measured to be 0.7627 gm/cm3. The critical and background amplitudes of isobaric thermal expansion coefficient αpc and αpbare calculated to be 4×10-6 K-1, 6×10-4 K-1 respectively. The pressure derivative of the critical temperature Tc′for the binary is calculated to be 1.083 ×10-8 K/Pa. The universal quantity R+ξ of both binary liquid critical mixtures phenol – water and phenol – cyclohexane are calculated to be 0.2716 and 0.2699 respectively. The values are in a good agreement with the theoretical value of R+ζ.The two binary liquid critical mixtures belong to the class of universality "Two – Scale – Factor Universality".
- ItemSynthesis And Biological Activities of Curcumin Based Heterocylics(2015-04-21) Shawareb, NuhaA number of curcumin based heterocyclic derivatives pyrazoles, isoxazoles, and diazepine have been synthesized and evaluated for their antibacterial activities. The chemical structures of the newly synthesized compounds were verified on the basis of spectral and elemental methods of analyses. Investigation of antimicrobial activity of the compounds was done by disc diffusion method using Gram-positive (S. aureus) and Gram-negative (E. coli and P. aeruginosa) bacteria. All prepared compounds exhibited good antibacterial activities against Gram positive bacteria. Among all tested compounds, derivative 4 exhibited appreciable activity against Gram positive bacteria comparable to reference drugs.
- ItemPurification of Agricultural Soil from Organic Contaminants by Solar-Driven Photo- degradation with ZnO Nanoparticles: Laboratory and Pilot-Plant Scale Study(2015-04-21) Khraim, RazanPurification of the agricultural soil from toxic organic contaminants using solardriven photo-degradation was studied in the present research. This type of degradation was based on the availability of sunlight as a major source of power, low cost catalyst and possible photochemical degradation processes. The aim of this research is to find an effective and a low cost method for mineralization of chlorinated hydrocarbons contaminating agricultural soils, specifically 3chlorophenol (3-cp). This is a hazardous compound that results from pesticides use, certain factories residues and domestic detergents, and pollutes the soil. The present study involved two types of experiments: The laboratory scale study and the pilot-plant scale study. Two forms of catalysts were used: the lab-prepared ZnO and the commercial ZnO. The effect of certain factors such as, concentration of the contaminant, irradiation time, pH value, catalyst loading and application method on the contaminant degradation had been studied. The results showed an increase in the % photo- degradation when the amount of catalyst and irradiation time were increased. % photo-degradation was influenced by the concentration of contaminant as it showed a decrease. Acidic medium was found to be more suitable for the contaminant degradation than the basic medium. There were no significant differences between the powder form and spray form of the catalyst. Pilot-plant scale results were consistent with the lab-scale results, as the % photodegradation increased with the increase of time overall 4 days of irradiation.
- ItemPolymeric Microcapsules for Drug Delivery(2015-04-21) Abu-Ain, YounisPoly dl-lactide co-glycolide (PLG) is a biodegradable polymer that has a slow degradation rate and high permeability to small drug molecules. PLG microcapsules were prepared by emulsifying a polymer solution that consists of PLG/solvent (dichloromethane) into a continuous phase that consists of a nonsolvent solution (water and SDS as a surfactant). After emulsification, the solvent diffuses out of polymer droplets (liquid microcapsules) to the nonsolvent solution and then evaporates at the surface of the nonsolvent to the air, leaving behind it solid microcapsules, these microcapsules are centrifuged and dried to obtain microcapsules as powder. The encapsulation of the limonene within the polymer microcapsules was prepared, and limonene release was determined with time from polymer microcapsules prepared. The current study aims at studying the effect of the type of the nonsolvnet such as (SDS solution, methanol and ethanol) on the limonene release from polymer microcapsules. The drug release from the solid microcapsules was measured using spectroscopic techniques. The size of microcapsules was analyzed by optical light microscope. The PLG microcapsules were prepared using different concentrations of SDS solution, methanol, and ethanol and study of its impact on the size of the PLG microcapsules. The size of prepared microcapsules was measured by the light microscope. Our results show that as the concentration of nonsolvent increases in the process of preparing of PLG microcapsules the size of prepared microcapsules decreases and the limonene release increases from polymer microcapsules with decreasing the size of microcapsules. These results can be explained as follows: with increasing the concentration of methanol, ethanol or SDS, the viscosity of the nonsolvent increases and the interfacial tension decreases which increases the shear force applied on the droplets during emulsification. This lead to a decrease in size of obtained PLG microcapsules and smaller microcapsules are obtained. The increase in the concentration of SDS solution decreases the size of PLG microcapsules and the surface area-to-volume ratio of the microcapsules consequently increases thus the diffusion flux of limonene from microcapsules increased.
- ItemSpectrophotometric Determination of Some Metal Ions via Complex Formation with Carboxylated Tris(2-aminoethyl)amine Chelating Agent(2015-04-21) Masharqah1, JulnarAn aminopolycarboxylic acid chelating agent tris(2-aminoethyl)aminehexaacetic acid (TAHA) was prepared and characterized. The TAHA was prepared from tris(2aminoethyl)amine and potassium chloroacetate by nucleophilic substitution reaction. FT-IR spectroscopy was used to ensure the formation and elucidate the purity of the potassium salt and the acid form of TAHA. TAHA forms stable complexes with copper(II) ions and some other metal ions at pH 10. The complexation behavior was studied by spectrophotometry at the complex maximum wavelength. Mixtures of Cu(II) and other metal ions (M2+; Ca2+, Co2+, Ni2+, Cd2+) were titrated with TAHA at pH 10. [Cu(NH3)4]2+ complex is more stable than [M(NH3)4]2+. Thus, at the beginning, TAHA replaces ammonia in [M(NH3)4]2+ complex until completion. Then it exchanges ammonia from [Cu(NH3)4]2+ to form Cu(II)– TAHA complex. As expected, TAHA does not form complexes with alkali metal ions. The stoichiometry of ligand - to - metal was found to be 1:1 for the metal ions studied. The stability constant of Cu(II)–TAHA complex was determined to be 1.86×105 by using the continuous variation method. The complex showed a good stability for an extended period of time. Beer’s low was obeyed over the concentration range 3.0×10–4 M – 1.2×10–2 M for Cu(II) solution. The results of the quantitative determination of Cu(II) gave LOD and LOQ values of 7.285×10–6 M and 2.428×10–5 M respectively. The relative standard deviation for five replicate samples was found to be 1.088% and 4.804% for 1.2×10–2 M and 3.0×10–4 M respectively.