Fluidization process is widely used by a great assortment of industries worldwide and represents a trillion dollar industry [6]. They are currently used in separation, classification, drying and mixing of particles, chemical reactions and regeneration processes; one of these processes is the mass transfer from an immersed surface to a gas fluidized bed
This research investigates the adsorption isotherm and adsorption kinetics of nitrogen from air using packed bed of Li-LSX zeolite to get medical oxygen. Experiments were carried out to estimate the produced oxygen purity under different operating conditions: input pressure of 0.5 – 2.5 bar, feed flow rate of air of 2 – 10 L.min-1 and packing height of 9-16 cm. The adsorption isotherm was studied at the best conditions of input pressure of 2.5 bar, the height of packing 16 cm, and flow rate 6 Lmin-1 at ambient temperature, at these conditions the highest purity of oxygen by this system 73.15 vol % of outlet gas was produced. Langmuir isotherm was the best models representing the experimental data., and the m
... Show MoreBackground: obesity is an important cause of adverse health problems, including male infertility. Testosterone is essential for spermatogenesis and permits the release of mature sperms. In the absence of testosterone stimulation, spermatogenesis does not proceed beyond the meiosis stage. Aromatase expression is directly related to the degree of adiposity; it is dependent on cytokine stimulation and requires the presence of glucocorticoids, 17β-estradiol in the plasma of adult men is formed by aromatization convert testosterone and androstinedione to 17β-estradiol Apoptosis is an important process in the context of germ cells since they undergo both mitosis and meiosis, and this process is affected by
... Show MoreCoated sand (CS) filter media was investigated to remove phenol and 4-nitrophenol from aqueous solutions in batch experiments. Local sand was subjected to surface modification as impregnated with iron. The influence of process variables represented by solution pH value, contact time, initial concentration and adsorbent dosage on removal efficiency of phenol and 4-nitrophenol onto CS was studied. Batch studies were performed to evaluate the adsorption process, and it was found that the Langmuir isotherm effectively fits the experimental data for the adsorbates better than the Freundlich model with the CS highest adsorption capacity of 0.45 mg/g for 4-nitrophenol and 0.25 mg/g for phenol. The CS was found to adsorb 85% of 4-nitrophenol and
... Show MoreThis paper reports an experimental study regarding the influence of vertical oscillations on the natural convection heat transfer from a vertical channel. An experimental set-up was constructed and calibrated; the vertical channel was tested in atmosphere at 25o
C. The channel-to-ambient temperature difference was varied with the power supply to the electrical heater ranging between
15W to 70W divided into five levels. Data sets were measured under different operating condition from a test rig under six vibrating velocities (VVs) levels ranging from (5-30 m/s) in addition to the stationary state. The results show that the maximum heat transfer enhancement factor (E) occurs at Rayleigh number (Ra=2.328×103 ) and vibrational Reynol
Recent studies have proved the important role of fungi in the biodegradation of oil pollutants. The present study aims to find the optimal conditions for the fungi to get the best rate of the biodegradation of the polycyclic aromatic hydrocarbon (PAHs) (Naphthalene) compounds. Soil samples were taken from 18 different sites polluted with oil wastes and cultured then obtained 312 isolated fungi from 64 replicates Primarily screening were done on fungal isolates on solid media containing naphthalene the results revealed that 25 fungal isolates gave good growth, 47 fungal isolates gave Moderate growth, 66 gave weak growth and 147 fungal isolates gave no growth on Naphthalene solid media.
Then secondary screening were done on 25 fungal is
Recent studies have proved the important role of fungi in the biodegradation of oil pollutants. The present study aims to find the optimal conditions for the fungi to get the best rate of the biodegradation of the polycyclic aromatic hydrocarbon (PAHs) (Naphthalene) compounds. Soil samples were taken from 18 different sites polluted with oil wastes and cultured then obtained 312 isolated fungi from 64 replicates Primarily screening were done on fungal isolates on solid media containing naphthalene the results revealed that 25 fungal isolates gave good growth, 47 fungal isolates gave Moderate growth, 66 gave weak growth and 147 fungal isolates gave no growth on Naphthalene solid media.
Then secondary screening were done on 25 fungal is
The possibility of predicting the mass transfer controlled CaCO3 scale removal rate has been investigated.
Experiments were carried out using chelating agents as a cleaning solution at different time and Reynolds’s number. The results of CaCO3 scale removal or (mass transfer rate) (as it is the controlling process) are compared with proposed model of prandtl’s and Taylor particularly based on the concept of analogy among momentum and mass transfer.
Correlation for the variation of Sherwood number ( or mass transfer rate ) with Reynolds’s number have been obtained .
Experiments were carried out to investigate natural convection heat transfer in an inclined uniformly heated circular cylinder . The effects of surface heat flux and angle of inclination on the temperature and local Nusselt number variations along the cylinder surface are discussed . The investigation covers heat flux range from 92 W/m² to 487 W/m², and angles of inclination 0° ( horizontal) , 30° , 60° and 90° (vertical) . Results show an increase in the natural convection as heat flux increases and as angle of inclination moves from vertical to horizontal position. An empirical equation of average Nusselt number as a function of Rayliegh number was deduced for each angle of inclination .
A microbubble air flotation technique was used to remove chromium ions from simulated wastewater (e.g. water used for electroplating, textiles, paints and pigments, and tanning leather). Experimental parameters were investigated to analyze the flotation process and determine the removal efficiency. These parameters included the location of the sampling port from the bottom of the column, where the diffuser is located to the top of flotation column (30, 60, and 90 cm), the type of surfactant (anionic, SDS, or cationic, CTAB) and its concentration (5, 10, 15, and 20 mg/L), the pH of the initial solution (3, 5, 7, 9, and 11), the initial contaminant concentration (10, 20, 30, and 40 mg/L), the gas flow rate (0.1, 0.2, 0.3, and 0.5 L/mi
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