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.
Magnetic nanoparticles (MNPs) of iron oxide (Fe3O4) represent the most promising materials in many applications. MNPs have been synthesized by co-precipitation of ferric and ferrous ions in alkaline solution. Two methods of synthesis were conducted with different parameters, such as temperature (25 and 80 ̊C), adding a base to the reactants and the opposite process, and using nitrogen as an inert gas. The product of the first method (MNPs-1) and the second method (MNPs-2) were characterized by x-ray diffractometer (XRD), Zeta Potential, atomic force microscope (AFM) and scanning electron microscope (SEM). AFM results showed convergent particle size of (MNPs-1) and (MNPs-2) with (86.01) and (74.14)
... Show MoreIn the present work the preparation of Cu2S alloy was done throughout mixing the sulphur and copper elements according to the proper atomic weight and then put in an evacuated quartz ampoule which then sealed and heated at 1273 K for five hours and left to cool. Thin films from Cu2S powder thicknesses of ~300nm were prepared by thermal evaporation technique on a glass substrate and under vacuum of 10 -5 mbar with rate of deposition 25nm/sec. The prepared thin films subjected to heat treatment at different temperatures(300, 373 , 473 and 573 K)for half an hour. The structures of Cu2S powder and films have been studied by X–ray diffraction technique. The result reveals that the preparedalloy has cubic structure a
... Show MoreTheoretical and experimental investigations of the transient heat transfer parameters of constant heat flux source subjected to water flowing in the downward direction in closed channel are conducted. The power increase transient is ensured by step change increase in the heat source power. The theoretical investigation involved a mathematical modeling for axially symmetric, simultaneously developing laminar water flow in a vertical annulus. The mathematical model is based on one dimensional downward flow. The boundary conditions of the studied case are based on adiabatic outer wall, while the inner wall is subjected to a constant heat flux. The heat & mass balance equation derived for specified element of bulk water within the annulu
... Show MoreThe earth-air heat exchanger (EHX) has a promising potential to passively save the energy consumption of traditional air conditioning systems while maintaining a high degree of indoor comfort. The use of EHX systems for air conditioning in commercial and industrial settings offers several environmental benefits and is capable of operating in both standalone and hybrid modes. This study tests the performance and effectiveness of an EHX design in a sandy soil area in Baghdad, Iraq. The area has a climate of the subtropical semi-humid type. Ambient air temperatures and soil temperatures were recorded throughout the months of 2021. During the months of January and June, the temperatures of the inlet and outflow air at varying air veloci
... Show MoreVarious approaches are employed to enhance the heat transfer coefficient and Nusselt number inside the channels. One of the techniques employed for these enhancements is the utilization of porous media. In the current article, a practical investigation of forced convection heat transfer in a rectangular cross‐section channel (0.05 × 0.1 m2) with 0.25 m length is conducted. A heater with a heat flux range (450–6000 W/m2) is imposed under a copper plate, and the other sides are covered by insulation layers. The air is considered as a working fluid with
Abstract:
Central banks seek to control and supervise credit and follow it up effectively due to the high credit risks surrounding it that may lead to damage to banks, and may even lead to damage to the reputation and confidence of the banking system as a whole.
The main role of supervisory control is to control credit by controlling it from excessive expansion during periods of economic inflation or its revitalization and improvement and expansion of credit transactions in cases of economic recession, or when central banks desire to support the national economy or support a sector of various
... Show MoreAs a result of the entry of multinationals companies in Iraq for investing in the joint projects through conducting agreements and contracts for work on important and strategic projects to get the necessary funds and various experiences which characterize the foreign participant sides that Iraq currently needs them and because of the non-applying the accounting processing stipulated in the unified accounting system in addition to the absence of a local accounting bases as well as the default of the participant contracts on indicating the accounting methods about those projects which are considered one of the bases that enables auditors in the public sector to depend on it, thus the research paper deals with studying an
... Show MoreThis research aims at studying and analyzing the creative research thinking of the educational staffs in private universities and colleges, and also the role of incentives, in its materialistic and moral sides in the development of such thinking and the pack of restraints which cause decline in interest level of the scientificresearch, and its weak role in the development of universities in Iraq, despite the interest of the Ministry of Higher Education and Scientific Research in Iraq in scientific research as part ofits academic and humanitarian targets.Based on study and analysis, and the using if some of statistical methods such as the Alpha Chronobaghcoefficient and the (T. Test)(F. Test),the research reached a number of conclusions.
... Show MoreObjectives: The study aims to evaluate the application of monitoring indicators for maternal, newborn and
child health through the evaluation of impact and coverage health indicators and to evaluate the usefulness of the
application of these indicators at sub primary health care centers in Baghdad City.
Methodology: A descriptive comparative design, which is using the evaluation approach, has been steered at
Sub Primary Health Centers of Baghdad City in order to evaluate the application; impact and coverage, and the
usefulness of monitoring indicators for maternal, newborn and child health from December 4th 2017 to April 29th
2018. A multistage, "non-probability" convenient, sample is selected for the present study. A t
Objective(s): To evaluate and compare between Health Promotion Program for the Prevention of Epidemics at Primary Health Care Centers in Baghdad City.
Methodology: A descriptive study, using the evaluation and comparative approaches, is conducted to evaluate health promotion program for the prevention of epidemics at primary health care centers in baghdad city from October 15th 2019 through March 1st 2020. A purposive, non-probability, sample of (42) health promotion unit officers were recruited from the same number of primary health care centers which were divided into (14) main, (14) sub and (14) family medicine primary health care centers i
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