In this paper a comparison of the experimental of evacuated tube solar water heater systems with and without mirror flat reflector. The aim of using the reflector to improve thermal efficiency, and the data gathered which are (temperature, solar irradiation and time) for three days were compared. the results from compared data the temperature lower increase in evacuated tube solar water heater system without reflector than the temperature increase in evacuated tube solar water heater system with reflector .The results show (53, 39, 35) % for three days respectively that the evacuated tube solar water heater system with reflector has higher thermal efficiencies than the results (47, 28, 30) % for three days respectively thermal efficiencies in the system without reflector in Iraq.
Rating systems for evaluating the sustainability of communities are an essential tool that is increasingly applied throughout the developed world to set criteria indicators to optimize the physical, social, economic, and environmental potential within such communities. Rating systems vary based on existing disparities among societies and their unique building and physical planning practices. Iraqi cities lacked the adaptation of a formal methodology or sustainability rating system to correctly measure the built environment’s sustainability indicators. This research attempts to review the most substantial rating systems to measure the sustainability of communities worldwide to form a
This article makes it possible to verify the role of quality management in strengthening the innovation process. The first hypothesis, according to which the quality (certification ISO 9001) influences the innovation positively, is confirmed for certain innovation indicators. Another hypothesis indicates that there are the levels of quality which develop the innovation process in diverse ways. The results indicate that for some domains of innovation, the performance of innovation of enterprises that have a very increased level of quality is higher than those of enterprises with an average quality, which in return is higher than those enterprises having a low quality level. Therefore, we discovered that the difference of performance innov
... Show MoreThe aim of this work is to study a modified version of the four-dimensional Lotka-Volterra model. In this model, all of the four species grow logistically. This model has at most sixteen possible equilibrium points. Five of them always exist without any restriction on the parameters of the model, while the existence of the other points is subject to the fulfillment of some necessary and sufficient conditions. Eight of the points of equilibrium are unstable and the rest are locally asymptotically stable under certain conditions, In addition, a basin of attraction found for each point that can be asymptotically locally stable. Conditions are provided to ensure that all solutions are bounded. Finally, numerical simulations are given to veri
... Show MoreIn this paper, a mathematical model consisting of harmful phytoplankton and two competing zooplankton is proposed and studied. The existence of all possible equilibrium points is carried out. The dynamical behaviors of the model system around biologically feasible equilibrium points are studied. Suitable Lyapunov functions are used to construct the basins of attractions of those points. Conditions for which the proposed model persists are established. The occurrence of local bifurcation and a Hopf bifurcation are investigated. Finally, to confirm our obtained analytical results and specify the vital parameters, numerical simulations are used for a hypothetical set of parameter values.
This study included the compromised the containing Hardness and some ions of treated water in central Karbala drinking water treatment station with Iraqi and international drinking water criteria. Also, this study was attempted to focus on probable pollution sources. The Hardness and other waters salts Sulphates (SO4), Chloride ion (Cl-), Calcium ion (Ca+2), and Magnesium ion (Mg+2) tests criteria were determined on water samples taken from Al-Hussainia River water source, treated drinking water during October-November 2013 to August - September 2014.Study results revealed an increasing in Total hardness (TH), sulfate, chloride, calcium, in winter (December- January) 2014. In addition, the results showed a decrease in above mentioned cri
... Show MoreIn this study, the stresses and displacement around a tunnel opening under water body in Baghdad city, middle of Iraq, during excavation and lining are discussed. For this purpose, the finite element method (FEM) was adopted as an effective approach to analyze the problem using (SIGMA/W) program. The research includes the study of the behavior of soil due to excavation of a tunnel by calculating the displacements and stresses in three positions of the tunnel (crown, wall, and invert) during the various stages of construction. The surface settlement is also studied. The finite element analyses were carried out Using (Elastic- plastic) and (linear elastic) models for the soil and the concrete liner respectively.
Attempts were made over the years to achieve economic and easy methods for water purification. This could well save time, cost, and earn a good process quality for many countries. This study aims to enhance the purification process parameters for Congo red dye polluted water and introduce a developed methodology with an impact on many associated parameters such as the time for water purification process. The research proposes a method to achieve this time reduction by mixing gold nanoparticle (AuNPs) (prepared by chemical reduction method) with Titanium dioxide nanoparticles (TiO2NPs) (prepared by sol-gel techniques). The resulting mixture is incorporated into PVA host to synthesize a hard disk used as a purification d
... Show MoreGlucoamylase from black Aspergillus niger isolate was purified by ammonium sulfate precipitation and sephadex G 200 filtration. A trial for the purification of glucoamylase resulted in an enzyme with a specific activity of 6472 unit/mg protein with 10 times fold. The main goal of the present work was to test this enzyme in hydrolyzing the raw starch. Two substrates were used: corn starch and potato starch 2% (w/v). The effect of enzyme dosage and thermal processing of substrate on kinetics and efficiency of hydrolysis were studied. The results suggested that the glucoamylase activity is increased as the increase of enzyme concentration and the enzyme was sufficiently effective in hydrolyzing tested raw starch, and thermal modification of
... Show MoreThis study examined the effects of water scarcity on rural household economy in El Fashir Rural Council / North Darfur State- western Sudan. Both quantitative and qualitative methods were used as to get a deeper understanding of the impact of water scarcity on the rural house economy in the study area. 174 households out of 2017 were selected from 45 villages which were distributed in eight village councils forming the study area. Statistical methods were used to manipulate the data of the study. The obtained results revealed that water scarcity negatively affected the rural household economy in the study area in many features. These include the followings: much family efforts and time were directed to fetch for water consequentl
... Show MoreBackground: Tooth eruption is a localized process in the jaws which exhibits precise timing and bilateral symmetry. Develop within the jaws and their eruption is a complex infancy process during which they move through bone to their functional positions within the oral cavity. For species with more than one set of teeth, eruption of the second set also accomplishes. The key to the successful clinical management of tooth eruption consists of understanding that this process consists largely of the local regulation of alveolar bone metabolism to produce bone resorption in the direction of eruption and shift and formation of bone at the opposite side.The amniotic sac contains a considerable quantity of stem cells. These amniotic stem cells are
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