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alkej-287
Cultivation of Microalgae Chlorella vulgaris in Airlift photobioreactor for Biomass Production using commercial NPK Nutrients
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Airlift reactors are widely used in the chemical and biochemical applications as effective contactors for mass and heat transfer. The main advantages of airlift contactor compared with simple bubble column are ease of construction, low shear rate, high capacity, good mixing and liquid circulation without mechanical agitators and circulating pumps.

In this work, growth characteristics of Chlorella vulgaris microalgae were studied in an internal loop airlift photobioreactor for biomass production. The bioreactor operated under batch and semi-continuous culture mode using commercially available 20:20:20+TE NPK fertilizer as nutrients. The experiments were conducted to evaluate the growth rate and biomass productivity of Chlorella vulgaris microalgae as affected by several factors such as nutrients concentration (20-80 mg/L), inlet air flow rate (2-8 LPM), and harvesting ratio (10-30 vol.%). The growth rate and biomass productivity of Chlorella vulgaris was determined as changes in optical density using UV-spectrophotometer. The results of batch operation showed that the growth rate of Chlorella vulgaris microalgae was increase with increasing of NPK nutrient concentration used but the access to the stationary phase of growth was delayed. The rate of growth was also increase with the increase in air flowrate to a limit then decrease. On the other hand the airlift photobioreactor can be operated in semi- continuous mode successfully by choosing the optimum conditions from the batch step which was 40 mg/L NPK nutrients concentration and 6 LPM and air flowrate. Several ratios of reactor content were harvested and the maximum biomass productivity was 0.142 g/L.day when harvested 10 vol.% every two days.

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Publication Date
Mon Nov 01 2021
Journal Name
Iop Conference Series: Earth And Environmental Science
Effect of Using Different Levels of Spirulina Algae (Spirulina Platensis) in The Diet on Concentration, Types of Fatty Acids, Oxidation Indicators, and Sensory Characteristics of Broiler Carcasses
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Abstract<p>This study was conducted at the Poultry Research Station of the Agricultural Research Department/Ministry of Agriculture in Abu Ghraib for the period from 25/2/2019 to 7/4/2019 (42 days) with the aim of using several levels of Spirulina (SP)<italic>Spirulina platensis</italic>in broiler diets. And their effect in the concentration and types of fatty acids, oxidation indices and sensory characteristics of the broiler carcass, 400 birds were used in this experiment One day old broiler birds of the Ross 308 strain are un sexed, with an average starting weight of 40 g/bird, and the birds were randomly distributed into five treatments with four replications per treatment (20 birds/duplicate). Th</p> ... Show More
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Publication Date
Sat Dec 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Comparison of the method of partial least squares and the algorithm of singular values decomposion to estimate the parameters of the logistic regression model in the case of the problem of linear multiplicity by using the simulation
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The logistic regression model is an important statistical model showing the relationship between the binary variable and the explanatory variables.                                                        The large number of explanations that are usually used to illustrate the response led to the emergence of the problem of linear multiplicity between the explanatory variables that make estimating the parameters of the model not accurate.    

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Publication Date
Sun Sep 07 2008
Journal Name
Baghdad Science Journal
A Fixed Point Theorem for L-Contraction in Generalized D-Metric Spaces
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We define L-contraction mapping in the setting of D-metric spaces analogous to L-contraction mappings [1] in complete metric spaces. Also, give a definition for general D- matric spaces.And then prove the existence of fixed point for more general class of mappings in generalized D-metric spaces.

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Publication Date
Thu Dec 14 2023
Journal Name
Iop Conf. Series: Earth And Environmental Science
Calculating some Powers and Traction Force for Two Plows in Primary Tillage
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Traction force and power requirement when performing primary tillage occupy the minds of almost farmers, this field research had aim to determine and calculate the pulling force of the most commonly used moldboard and chisel plows, the research conducted in silt clay loam for chisel and moldboard plows as the main factor, two depths of tillage 18 and 25 cm as a second factor and three speeds of tractor 2.55, 4.30 and 6.15 km.h-1 as a third factor. Moldboard plow recorded least traction force 7.550 kN, drawbar power 11.583 hp, power losses due to slippage 1.088 hp, power on the rear axle of the tractor 15.770 hp and brake horse power 17.495 hp. Chisel plow recorded best traction efficiency 76.217 % and total traction efficiency 68.659 %. Dep

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Publication Date
Wed Jun 06 2001
Journal Name
المجلة العراقية للعلوم الاحصائية
Suggest formulas for estimating carry-over effects in two-period changeover design
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This research aims to suggest formulas to estimate carry-over effects with two-period change-over design, and then, all other effects in the analysis of variance of this design, and find the efficiency of the two-period change-over design relative to another design (say, completely randomized design).

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Publication Date
Wed Apr 21 2021
Journal Name
Turkish Journal Of Computer And Mathematics Education
Algebraic thinking skills included in the mathematics textbook for middle third grade
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The aim of the current research is to find out the extent to which algebraic thinking skills are included in the mathematics textbook for the third intermediate grade for the academic year (2020-2021) by answering the main research question:What algebraic thinking skills are included in the mathematics textbook for middle third grade?The descriptive and analytical approach was used, and to achieve the goal of the research, a list of the main algebraic thinking skills and the sub-skills were prepared, and after analyzing the content of the mathematics textbook, the stability of the analysis was verified through the analysis over time and across individuals using the Holsti equation, and

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Publication Date
Fri Jan 01 2016
Journal Name
5th Iet International Conference On Renewable Power Generation (rpg), 2016, London, Uk
Electrical Machine Design for use in an External Combustion Free Piston Engine
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Publication Date
Wed Dec 30 2020
Journal Name
Journal Of Planner And Development
"2030 City Tour". New paradigm for intervention in the XXI century cities
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THE ACTUAL SOCIETY MODEL

Our society model has been showing signs of exhaustion since the end of the XX century. The recent appearance of the Covid-19 virus is another consequence of humanity's distance from Nature and the environment it inhabits. Also, climate change, environmental deterioration, loss of biodiversity, overexploitation of natural resources, and social inequality are some of the consequences derived from this separation between society and Nature. We must change our operating habits. Inevitably from a society based on the market, hyper consumption, fossil energy and individual enrichment at all costs, we will have to change to another

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Publication Date
Thu Apr 01 2021
Journal Name
Iop Conference Series: Earth And Environmental Science
Comparative study for Environmental Impact Assessment in Environmental Iraqi and Saudi legislation
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Abstract<p>Countries are developing the spatial development of their societies through the projects that they undertake in various ways, and this development may be cause great impact on the environment, which also depend on the type of development, whether industrial, agricultural, or service and after the problems that occurred as a result of development on the environment, most of the countries currently did to legislating laws Environmental and some other procedures before granting environmental approvals for the purpose of establishing spatial development projects. One of the most important of these laws and regulations is Environmental impact assessment (EIA). The environmental impact asse</p> ... Show More
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Publication Date
Mon Aug 18 2025
Journal Name
Journal Of Almaarif University College
Land Cover Change in Al-Jadriya Twist For the Period (1976-2024)
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The study addressed the change in the nature of the land cover of the Al-Jadriya Twist area for the period from 1976-2024 with an area of (140 km2)and for a period of (48 years) based on satellite images and their analysis using geographic information systems. The main classifications of the area were reached (water cover, residential areas, vegetation cover, in addition to empty, unused areas). The extracted data indicate a decrease in the water cover and the change rate reached (-14.29) and the residential areas increased with a change rate of (28.26), while the vegetation cover rate was recorded from (45 km2) to (66 km2) and the empty areas had a change rate of (-78.57).

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