A lotic ecosystem is considered a source of carbon dioxide (CO2) in the atmosphere where it becomes supersaturated with CO2, which contributes to the global carbon cycle. To enhance our comprehension of the roles of CO2 in rivers, an outdoor experiment was designed with controlled carbon source inputs to investigate the roles of the dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) in the phytoplankton community. Plastic enclosures were installed in the Tigris River within Baghdad for that goal. Samples were collected on the first day, as well as on the 5th and the 12th days from 14 enclosures. The enclosures were treated by artificial glucose (C6H12O6) (10, 20, 30mg/ l) as DOC sources, while sodium bicarbonate (NaHCO3) (10, 20, 30μM) was used as a DIC source. The results showed that the concentration of nitrate (NO3 -) and phosphate (PO4 3-) changed over time and weren’t affected by the treatments. On the other hand pH, DOC, and CO2 concentrations were affected by treatments. Moreover, our results indicated that DOC and DIC treatments had a direct impact on phytoplankton biomass growth via increasing chlorophyll (Chl) concentration. Overall, it was concluded that different carbon sources (DOC and CO2) could be essential factors that shape river ecosystems function through influencing the base of food webs.
The research is concerned with studying the characteristics of Sustainable Architecture and Green Architecture, as a general research methodology related to the specific field of architecture, based on the differentiation between two generic concepts, Sustainability and Greening, to form the framework of the research specific methodology, where both concepts seem to be extremely overlapping for research centers, individuals, and relevant organizations. In this regard, the research tend towards searching their characteristics and to clearly differentiates between the two terms, particularly in architecture, where the research seeks understanding sustainable and green architectures, how they are so close or so far, and the
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Actual and effective organizational dynamic capabilities in the work environment contribute to a number of factors that contribute to the organization's ability to manage its human talents. Thus, the study sought to identify the level of contribution of organizational dynamic capabilities to human talent management based on their dimensions in the investigated organization by determining the level of relationship and impact between these variables. The presidency of Mosul University was chosen as a field for the current study, and data were collected by adopting the questionnaire form as the main tool for the study. The study used a deliberate sample of (42) administrative leaders in the investigated organization and adopte
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The recognition of the dynamic organizational capabilities in their actual and influential extent in the work environment achieves a set of positive data that can fall under the addition axes, particularly with regard to the organization's ability to manage human talents in them, so the researchers sought to identify the level of contribution of dynamic organizational capabilities in the management of human talents in terms of Keep them away in the research organization by indicating the level of relationship and impact between them. The presidency of Mosul University was chosen as a field for the current study, and data were collected by adopting the questionnaire form as the main tool for the study. The study used a deliberate
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There is no doubt that Agricultural Policy is the main responsible for the degrading in Agricultural sector in Iraq during the period 2003-2013, and that was very clear from magnitude of indicators because of little sharing of each of agricultural product in GDP because it was (9.38%) in average during the study period and the annual changing of it was negative (-5.82%), and there is increasing in deficit of trade balance in Agriculture during the study period about (4185.73) million US$, and the percentage of agricultural exports from total exports was (0.14%) in average only. The foreign trade policy in Agricultural products also cannot determine map of Revealed Comparative Advantage (RCA) of Agricultural products and crops. The study sh
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The study aimed to find out the relationship between the dimensions of internal control systems and the availability of an effective governance framework in the Sudanese banks. The study used descriptive and analytical method for collecting and analyzing the study data using SPSS program. The questionnaire was used as an analysis tool. The target sample of Sudanese bank employees, the study found several results, including that the bank avoids methods that lead to the rational use of available resources, and identifies and separation of tasks among employees, in addition to rapid response to reports The study found several recommendations, including the need for a list of banks that are sufficiently flexible and comp
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A numerical study of the two-dimensional steady free convection flow in an inclined annulus between two concentric square cavities filled with a porous medium is presented in this paper for the case when the side outer walls are kept with differentially heated temperature while the horizontal outer walls and the inner walls are insulated. The heated wall is assumed to have spatial sinusoidal temperature variation about a constant mean value. The Darcy model is used and the fluid is assumed to be a standard Boussinesq fluid. For the Cartesian coordinate system, the governing equations which were used in stream function form are discretized by using the finite difference method with successive under – relaxation method (SUR) and are solv
... Show MoreA numerical simulation is made on the thermal lensing effect in an laser diode end-pumped Nd:YAG laser rod. Based on finite element method (FEM), the laser rod temperature distribution is calculated and the focal length is deduced for a Gaussian and super-Gaussian pump beam profiles.
At the pump power of 20W, the highest temperature located at the center of end-pumped face was 345K, and the thermal lens focal length was 81.4mm along the x-z axis.
The results indicate that the thermal lensing effect sensitively depend on the pump power, waist radius of the pump beam and the pump distribution in a laser rod geometry.
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The present work presents design and implementation of an automated two-axis solar tracking system using local materials with minimum cost, light weight and reliable structure. The tracking system consists of two parts, mechanical units (fixed and moving parts) and control units (four LDR sensors and Arduino UNO microcontroller to control two DC servomotors). The tracking system was fitted and assembled together with a parabolic trough solar concentrator (PTSC) system to move it according to information come from the sensors so as to keep the PTSC always perpendicular to sun rays. The experimental tests have been done on the PTSC system to investigate its thermal performance in two cases, with tracking system (case 1) and without trackin
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