Aluminum oxide (ALO) was grafted by acrylic acid monomer (AlO-AM) and then, it was polymerized to produce alumina grafted poly(acrylic acid) (AlO-AP). The prepared AlO-AM and AlO-AP were characterized by Fourier-transform infrared, differential scanning calorimetry , thermogravemetric analyzer and particle size distribution. Adsorption equilibrium isotherms, adsorption kinetics and thermodynamic studies of the batch adsorption process were used to examine the fundamental adsorption properties of phenol (P) and p-chlorophenol (PCP). The experimental equilibrium adsorption data were analyzed by three widely used two-parameters Langmuir, Freundlich and DubininRadushkevich isotherms. The maximum P and PCP adsorption capacities based on the Langmuir isotherm were calculated at 56.818, 78.741, 92.593, 80.002, 103.579 and 131.579 mg/g for P and PCP onto ALO, AlO-AM and AlO-AP, respectively. The experimental kinetic data were analyzed by using Pseudo-first order and pseudo-second order kinetic models. A comparison of the kinetic models on the overall adsorption rate showed that the adsorption system can be best described by the pseudo-second order kinetics. Based on the calculated thermodynamic parameters such as enthalpy (DH°), entropy (DS°) and Gibb’s free energy changes (DG°). The negative DG° and DH° values indicated that the adsorption of P and PCP by AlO-AM and AlO-AP adsorbent was feasible, spontaneous and the process was exothermic in nature.
Background: The isatin molecule is present in many natural substances, including plants and animals, and is used to prepare compounds with various biological activities. Objectives: To synthesize a new series of isatin derivatives with the expectation that they will have antimicrobial activity. Methods: Thiazole Schiff bases were synthesized from various Mannich bases of isatin to evaluate their antimicrobial properties. Initially, Mannich bases (2a–e) were synthesized by reacting isatin with formaldehyde and different secondary amines. Subsequently, they were treated with 2-aminothiazole to yield the final compounds (3a–e). Spectroscopic characterization was done via FT-IR and 1H-NMR. The antimicrobial screening was conducted o
... Show MoreWe have synthesized many metal (II) complexes using curcumin L1 as the major ligand and 2-(1H-Benzimidazol-2-yl) aniline L2 as a supporting ligand. The complexes were characterized by spectroscopy methods such as; molar conductivity, elements microanalysis, Fourier-transform spectroscopy (FT-IR), UV-vis, and mass spectroscopy. Both curcumin ligands and L2 were found to be capable of binding to M(II) and metal ions via their two N atoms, according to the data. The formula for the complexes is the same. [M (L1)(L2)H2OCl], where M is Ni(II), Co(II), Cu(II), Cd(II), and Hg(II) (II). Octahedral complexes are proposed for the prepared compounds. The bio-actives suggested that the complexes are effective against bacteria and fungus on a mi
... Show MoreA simple, precise, and sensitive spectrophotometric method has been established for the analysis of doxycycline. The method includes direct charge transfer complexation of doxycycline withp-Bromanil in acetonitrileto form a colored complex. The intensely colored product formed was quantified based on the absorption band at 377 nm under optimum condition. Beer’s law is obeyed in the concentration range of 1–50 μg.mL-1 with molar absorptivity of 1.5725x104 L.mol-1.cm-1, Sandell's sensitivity index (0.0283) μg.cm-2, detection limit of 0.1064 μg.mL-1, quantification limit 0.3224 μg.mL-1 and association constant of the formed complex (0.75x103). The developed method could find application in routine quality control of doxycycline and has
... Show MoreBackground: During acrylic resin processing, the mold must be separated from the surface of the gypsum to prevent liquid resin from penetrating into the gypsum, and water from the gypsum seeping into the acrylic resin. For many years, tin foil was the most acceptable separating medium, and because it's difficult to apply, a tin-foil substitute is used. In this study, olive oil is used as an alternative to tin foil separating medium for first time, and evaluating its effect as a separating medium on some mechanical properties such as (indentation hardness and transverse strength) of acrylic resins denture base comparing it with those processed using tin-foil and tin foil substitute such as (cold mold seal) separating medium. Materials and M
... Show Moreفي البداية اود الاشارة الى ان فهم حقيقة الازمة هو ذو جانب فني يتعلق بالجينات الوراثية لنظام يملك في احيناته قدرة عالية على تفريخ المشتقات. هذا النظام الذي يزداد عقما وتدميرا يزداد قدرة على خلق النقود الائتمانية/المشتقات، وكلما اقتربنا اكثر من فهم هذا الجانب كلما اسقطت في ايدينا تلك التوصيفات الاكاديمية الجاهزة في نقص الرقابة والاشراف، تركيز المخاطر،....الخ التي تناولتها الكتابات الشائعة في معظم طروحات
... Show MoreLight naphtha one of the products from distillation column in oil refineries used as feedstock for gasoline production. The major constituents of light naphtha are (Normal Paraffin, Isoparaffin, Naphthene, and Aromatic). In this paper, we used zeolite (5A) with uniform pores size (5Aº) to separate normal paraffin from light naphtha, due to suitable pore size for this process and compare the behavior of adsorption with activated carbon which has a wide range of pores size (micropores and mesopores) and high surface area. The process is done in a continuous system - Fixed bed reactor- at the vapor phase with the constant conditions of flow rate 5 ml/min, temperature 180oC, pressure 1.6 bar and 100-gram weight o
... Show MoreAdsorption techniques are widely used to remove certain classes of pollutants from waters, especially those that are not easily biodegradable. Dyes represent one of the problematic groups. The removal of methyl green from waste water using bamboo was studied in batch and continuous system. In batch system equilibrium time and adsorption isotherm was studied at different concentrations (5, 10, 15, 20, 25 and 30 ppm) and 50 mg weight of adsorbent.
Langmuir and Freundlich equations were applied for adsorption isotherm data. Langmiur equation was fitted better than Freundlich equation (R2=0.984 for Langmuir equation).The maximum percentage dye removal obtained 79.4% and adsorption capacity was 15.5 mg/g. For continuous system the breakthr
The acrylic polymer composites in this study are made up of various weight ratios of cement or silica nanoparticles (1, 3, 5, and 10 wt%) using the casting method. The effects of doping ratio/type on mechanical, dielectric, thermal, and hydrophobic properties were investigated. Acrylic polymer composites containing 5 wt% cement or silica nanoparticles had the lowest abrasion wear rates and the highest shore-D hardness and impact strength. The increase in the inclusion of cement or silica nanoparticles enhanced surface roughness, water contact angle (WCA), and thermal insulation. Acrylic/cement composites demonstrated higher mechanical, electrical, and thermal insulation properties than acrylic/silica composites because of their lowe
... Show More