The use of multifunction additives in the lubricant sector has attracted great interest due to their ability to simultaneously improve and add multiple functions. This work describes the preparation and evaluation of over-based magnesium stearate detergent as a multifunction additive by the reaction of stearic acid with carbon dioxide gas in the presence of magnesium oxide nanoparticles and ammonia. The prepared over-based magnesium stearate was evaluated as a multifunction additive through blending it in various concentrations of 1-5 wt/wt% with sixty stock lubricating oils. The American Society for Testing and Materials (ASTM) and the Institute of Petroleum (IP) were used to determine the total base number (TBN), viscosity ind

Pharmaceuticals have been widely remaining contaminants in wastewater, and diclofenac is the most common pharmaceutical pollutant. Therefore, the removal of diclofenac from aqueous solutions using activated carbon produced by pyrocarbonic acid and microwaves was investigated in this research. Apricot seed powder and pyrophosphoric acid (45 wt%) were selected as raw material and activator respectively, and microwave irradiation technique was used to prepare the activated carbon. The raw material was impregnated in pyrophosphoric acid at 80◦C with an impregnation ratio of 1: 3 (apricot seeds to phosphoric acid), the impregnation time was 4 h, whereas the power of the microwave was 700 watts with a radiation time of 20 min. A series o

Red pigmented undecylprodigiosin produced by Streptomyces coelicolor (A3)2 is a
promising drug owing to its characteristics of antibacterial, antifungal,
immunosuppressive and anticancer activities. The culture of S. coelicolor in liquid
medium produces mainly the blue pigmented actinorhodin and only low quantities of
undecylprodigiosin. From an industrial point of view, it is necessary to find a strategy to
improve undecylprodigiosin production. The present study provides evidence that
cultivation of S. coelicolor on solid substrate resulted in a reversal in this pattern of
antibiotic production as the production of undecylprodigiosin was significantly increased
and actinorhodin was completely suppressed. Four di

In this study, pebble bed as an absorber and storage material was placed in a south facing, flat plate air-type solar collector at fixed tilt angle of (45°). The effect of this material and differ- ent parameters on collector efficiency has been investigated experimentally and
theoretically. Two operation modes were employed to study the performance of the solar air heater. An inte- grated mode of continuous operation of the system during the period of (11:00 am – 3:00 pm) and non-integrated mode in which the system stored the solar energy through the day then used the stored energy during the period of (3:00 pm – 8:00 pm). The results of parametric study in case of continuous operating showed that the maximum average temperatur

Mn(II), Co(II), Ni(II), Cu(II), and Cr(III) metal complexes with the ligand (L) [3-(2nitro benzylidene) amino-2-thioxoimidazolidin-4-one] have been prepared and characterized in their solid state using the elemental micro analysis (C.H.N.S), flame atomic absorption, UV-Vis spectroscopy, FT-IR, magnetic susceptibility measurements, and electrical molar conductivity. The ratio of metal to ligand [M:L] was got for all complexes in the ethanol by using the molar ratio method, which produced comparable results with those results obtained for the solid complexes. From the data of all techniques, octahedral geometry was proposed for Cr(III), Mn(II), and Co(II) complexes, while tetrahedral structure was proposed for Ni(II), Cu(II) complexes.

Metal complexes chrome(III), manganese(II), iron(III), cobalt(II), nickel(II), cupper(II) and zinc(II) with diazonium of 3-amino-2-chloropyridine of general formula [2-Cl-C₅H₃N≡N]_n[MX_m], where n=2 or 3 for divalent and trivalent metal, m= 4 or 6  were synthesized. The complexes have been characterized by flame atomic absorption, (C.H.N), molar conductance, magnetic susceptibility UV-vis spectra, infrared spectra,¹H-NMR spectroscopy and thermo gravimetric analysis (TGA and DTA). The measurements showed that the divalent metal ion complexes (M²⁺) have (1:2) M:L ratio with tetrahedral geometry around metal ions while the trivalent metal ions (M³⁺) formed (1:3) m

The present work investigates the effect of magneto – hydrodynamic (MHD) laminar natural convection flow on a vertical cylinder in presence of heat generation and radiation. The governing equations which used are Continuity, Momentum and Energy equations. These equations are transformed to dimensionless equations using Vorticity-Stream Function method and the resulting nonlinear system
of partial differential equations are then solved numerically using finite difference approximation. A thermal boundary condition of a constant wall temperature is considered. A computer program (Fortran 90) was built to calculate the rate of heat transfer in terms of local Nusselt number, total mean Nusselt number, velocity distribution as well as te

Highly-fluorescent Carbon Quantum Dots (CQDs) are synthesized in simple step by hydrothermal carbonization method of natural precursor such as orange juice as a carbon source. Hydrothermal method for synthesized CQDs requires simple and inexpensive equipment and raw materials, thus this method are now common synthesis method. The prepared CQDs have ultrafine size up to few nanometers and   several features such as high solubility in water, low toxicity, high biocompatibility, photo-bleaching resistant, Chemical inertness and ease of functionalization which qualifies it for use in many applications such as bio-imaging, photo-labeling and photo-catalysis.

       This research demonstrates the