Adsorption capacity of a waste biomass, date stones, for phenolic compounds such as phenol (Ph) and p-nitro phenol (PNPh) was investigated. The characteristics of such waste biomass were determined and found to have a surface area and iodine number of 495.71 m²/g and 475.88 mg/g, respectively. The effects of temperature, initial sorbate concentration, and contact time on the adsorption process were studied. Experimental equilibrium data for adsorption of Ph and PNPh on date stones were analyzed by the Langmuir, Freundlich and Sips isotherm models. The results show that the best fit was achieved with the Sips isotherm equation with maximum adsorption capacities of 147.09 and 179.62 mg/g for Ph and PNPh, respectively. The kinetic data were fitted to pseudo-first order, pseudo-second order and intraparticle diffusion models, and was found to follow closely the pseudo-second order model for both Ph and PNPh. The calculated thermodynamic parameters, namely AG, AH, and AS showed that adsorption of Ph and PNPh onto date stones was spontaneous and endothermic under examined conditions.
The kinetics of removing cadmium from aqueous solutions was studied using a bio-electrochemical reactor with a packed bed rotating cylindrical cathode. The effect of applied voltage, initial concentration of cadmium, cathode rotation speed, and pH on the reaction rate constant (k) was studied. The results showed that the cathodic deposition occurred under the control of mass transfer for all applied voltage values used in this research. Accordingly, the relationship between logarithmic concentration gradient with time can be represented by a first-order kinetic rate equation. It was found that the rate constant (k) depends on the applied voltage, the initial cadmium concentration, the pH and the rotational speed of cathode. It
... Show MoreThe purpose of the paper is to tind the degree of the approximation of a functions f be bounded , measurable and defined
in interval [a,h]by Bernstein polynomial in LP space 1 $ p < oo by
using Ditzian-Totik modulus of smootlmess and k 1n average modvlus of smoothness.
The possibility of using activated carbon developed from date palm seeds wastes as a permeable reactive barrier (PRB) to remove copper from polluted shallow groundwater was investigated. The activated carbon has been developed from date palm seeds by dehydrating methods using concentrated sulfuric acid. Batch tests were performed to characterize the equilibrium sorption properties of new activated carbon in copper-containing aqueous solutions, while the sandy soil (aquifer) was assumed to be inert. Under the studied conditions, the Langmuir isotherm model gives a better fit for the sorption data of copper by activated carbon than other models. At a pilot scale, One-dimensional column experiments were performed, and an integrated model ba
... Show MoreStrategic Cost Management Tools Under Technological Development and Change in Customer Tastes Critical Studies
A theoretical study including the effects of the fusion characteristics parameters on the fundamental fusion rate for the BEC state in D-D fusion reaction is deal with varieties physical parameters such as the fuels density, fuel temperature and the astrophysics S-factor are processed to bring an approximately a comparable results to agree with the others previously studies.
New series of metal ions complexes have been prepared from the new ligand 1,5- Dimethyl-4- (5-oxohexan-2- ylideneamino) -2-phenyl- 1H-pyrazol-3 (2H)-one derived from 2,5-hexandione and 4-aminophenazone. Then, its V(IV), Ni(II), Cu(II), Pd(II), Re(V) and Pt(IV) complexes prepared. The compounds have been characterized by FT-IR, UV-Vis, mass and 1H and 13C-NMR spectra, TGA curve, magnetic moment, elemental microanalyses (C.H.N.O.), chloride containing, Atomic absorption and molar conductance. Hyper Chem-8 program has been used to predict structural geometries of compounds in gas phase, the heat of formation, (binding, total and electronic energy) and dipole moment at 298 K.
Since the beginning of the second decade of the twenty-first century, Saudi Arabia tried to pursue an open foreign policy towards many countries in the Horn of Africa, especially with Ethiopia and Somalia, due to the geostrategic qualities that these two countries possess.Despite the development of Saudi foreign policy towards Ethiopia and Somalia, it was soon affected by the tension after the events that the Gulf states went through, that is, the Qatari crisis with Saudi Arabia,especially after most of the countries of the Horn of Africa adhered to a policy of neutrality towards the Gulf-Gulf crisis.
Thus it is expected that despite the geographical proximity and the historical, economic and political relations between Saudi Ara
... Show MoreBackground: One of the unique prosthesis for tooth or teeth replacement is the dental implant. Our attempt is using a biomaterial system that is easily obtained and applicable and has the ability to provoke osteoinductive growth factor to enhance bone formation at the site of application. One of these natural polymers is hyaluronic acid. Material and methods: Sixty machined surface implants from commercially pure titanium rod inserted in thirty NewZealand rabbits. Two implants placed in both tibia of each rabbit. The animals scarified at 1, 2 and 4 weeks after implantation (10 rabbits for each interval). For all of animals the right tibia’s implant was control (uncoated) and the left one was experimental (coated with 0.1ml Hyaluro
... Show MoreIn this work we present a detailed study on anisotype nGe-pSi heterojunction (HJ) used as photodetector in the wavelength range (500-1100 nm). I-V characteristics in the dark and under illumination, C-V characteristics, minority carriers lifetime (MCLT), spectral responsivity, field of view, and linearity were investigated at 300K. The results showed that the detector has maximum spectral responsivity at λ=950 nm. The photo-induced open circuit voltage decay results revealed that the MCLT of HJ was around 14.4 μs