Recently, microalgae have become a promising source in the production of biofuel. However, the cost of production is still the main obstacle to develop of this type of source. Although there are many extensive studies on the requirements provided for the cultivation of the microalgae, the study of the process, via the variables that affect the cultivation of microalgae, being still one of the important tasks to improve the production of biofuel. The present article is a serious attempt to investigate of use commercial fertilizer NPK (20:20:20+TE N: P: K) as considered a cheap nutrient medium in growth Chlorella vulgaris by comparison with traditional nutrient (Chu.10 medium). In addition, the current study addresses effect of different sparging periods of filtered air on the microalgae production. The experimental data showed that the use of the NPK fertilizer as cultivation medium in Chlorella vulgaris culture gives more growth rate of microalgae than that produced if the cultivation process was operated with Chu.10 medium. For example the maximum biomass concentration reaches to 0.3249 g L-1 when cultivated in NPK fertilizer, whereas reached to 0.212 g L-1 for cells cultivated in Chu.10 medium. In addition, the results proved that the aeration system in the cultivation can plays an important role in the activity of the microalgae with NPK medium, since it creates a convenient environment with low concentration of oxygen in the medium. The study showed that increasing aeration period for such a type of microalgae increases the growth rate.
Antibiotics present the greatest threat to soil and aquatic ecosystems among the different therapeutic groups of medicines (which include prescription drugs and treatments for cancer). The strongest drugs, antibiotics, have been utilized to stop the growth of microorganisms or eradicate them. Using high-performance liquid chromatography technology with fluorescence detection, the amounts of levofloxacin and tetracycline in the wastewater from three hospitals (Medical City, Al-Kindi, and Al-Yarmouk) were determined. Levofloxacin and tetracycline were chosen in this study because they are the most important water pollutants. These antibiotic residues were separated and measured using a gradient elution technique on a reverse-phase C18
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In this paper the queuing system (M/Er/1/N) has been considered in equilibrium. The method of stages introduced by Erlang has been used. The system of equations which governs the equilibrium probabilities of various stages has been given. For general N the probability of j stages of service are left in the system, has been introduced. And the probability for the empty system has been calculated in the explicit form.
The present work involved synthesis of several new N-Sulfamethoxazol derivatives imide on Polymeric chain by two steps. The first stip involved preparation of N- (sub.orunsub benzoyl and sub unsub acetyl) amidyl sub sulfamethoxazole (1-5) by condensation of sulfamethoxazole drug with many substituted acid chloride, then the second step include, preparation new five N-(acrly-N–sub or unsub benzoyl) imidyl substituted sulfamethoxazol(6-10) by reaction of poly acryloyl chloride with the prepared compound (1-5) in first stepin asuitable solvent in the presenceamount triethylamine (Et3N) with heating. The structure confirmations of all polymers wereconfirmed using FT-IR,1H-NMR,13C-NMR and UV spectroscopy. Other physical properties including so
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Five N-substituted acrylamides were prepared by reaction of substituted aromatic primary amines with acryloyl chloride in the presence of triethyl amine. The synthesized acrylamides were allowed to introduce copolymerization reaction with three vinylic monomers including acrylonitrile, methyl acrylate and methyl methacrylate respectively to obtain eleven new copolymers having different physical properties which may used in different applications.
In this work, porous Silicon structures are formed with photochemical etching process of n-type Silicon(111) wafers of resistivity (0.02.cm) in hydrofluoric acid (HF) of concentration (39%wt) under light source of tungeston halogen lamp of (100 Watt) power. Samples were anodized in a solution of 39%HF and ethanol at 1:1 for 15 minutes. The samples were realized on n-type Si substrates Porous Silicon layers of 100m thickness and 30% of porousity. Frequency dependence of conductivity for Al/PSi/Si/Al sandwich form was studied. A frequency range of 102-106Hz was used allowing an accurate determination of the impedance components. Their electronic transport parameters were determined using complex impedance measurements. These measu
... Show MoreOne of the most important processes to obtain gasoline with high octane numbers is isomerization. In this paper, Pt/TiO2 was prepared successfully by using the sol–gel method by hydrolysis of titanium tetraisopropoxide as a titania source with ethanol and then platinum was loaded on the synthesized catalyst; the result shows that the sample prepared has a good crystallinity with a surface area of about 85 m2 /g and a pore volume of 0.1938 cm3 /g, while XRD shows that the prepared sample was anatase phase. The efect of both temperature and liquid hourly space velocity of the prepared catalyst was achieved by hydroisomerization of n-hexane in a fxed bed reactor with a temperature of 200–275 °C and LHSV 0.5–2h−1. The results show
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The discussion in this paper gives several theorems and lemmas on the Sums of Squares of consecutive Carol Numbers. These theorems are proved by using the definition of carol numbers and mathematical induction method. Here the matrix form and the recursive form of sum of squares of consecutive Carol numbers is also given. The properties of the Carol numbers are also derived.
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