Massive multiple-input multiple-output (m-MIMO) is considered as an essential technique to meet the high data rate requirements of future sixth generation (6G) wireless communications networks. The vast majority of m-MIMO research has assumed that the channels are uncorrelated. However, this assumption seems highly idealistic. Therefore, this study investigates the m-MIMO performance when the channels are correlated and the base station employs different antenna array topologies, namely the uniform linear array (ULA) and uniform rectangular array (URA). In addition, this study develops analyses of the mean square error (MSE) and the regularized zero-forcing (RZF) precoder under imperfect channel state information (CSI) and a realistic physical channel model. To this end, the MSE minimization and the spectral efficiency (SE) maximization are investigated. The results show that the SE is significantly degraded using the URA topology even when the RZF precoder is used. This is because the level of interference is significantly increased in the highly correlated channels even though the MSE is considerably minimized. This implies that using a URA topology with relatively high channel correlations would not be beneficial to the SE unless an interference management scheme is exploited.
Successfully, theoretical equations were established to study the effect of solvent polarities on the electron current density, fill factor and efficiencies of Tris (8-hydroxy) quinoline aluminum (Alq3)/ ZnO solar cells. Three different solvents studied in this theoretical works, namely 1-propanol, ethanol and acetonitrile. The quantum model of transition energy in donor–acceptor system was used to derive a current formula. After that, it has been used to calculate the fill factor and the efficiency of the solar cell. The calculations indicated that the efficiency of the solar cell is influenced by the polarity of solvents. The best performance was for the solar cell based on acetonitrile as a solvent with electron current density of (5.0
... Show MoreThe current study included details of the anatomical characteristics of vegetative parts including the root, stem, leaf in cultivated Iraq for the species Brassciaaleraceacabbage, where the study dealt with the stomatal index and the rate of both the length and width of the stomatal complex and the thickness of the periderm, the tissue, cortex, vascular cylinder and pith. The parts were taken and measured after the plant was treated with brassinolide and the treated species with brassinolide and non-treated were measured and the study showed that there was a clear variation in the properties above.
The interactive websites are the interaction between the product and the user, and interactive design is based on the user interface for communication and how the interface responds to the user and how to help him to achieve his goals and enjoy the use of the interface. The interactive design is based on the design of interactive programs, i.e., programs that directly interact with the user, taking into account the different culture of the audience, the age group and many other factors. An example for the use of the user interface: Web designs, smartphone application designs and it even includes computer operating systems and electronic game interface. The interaction is the communication between the source and the receiver. The we
... Show MoreIn a world of limited space, the owners are always surrounded by others next to them, and, consequently, there is hardly any activity which the owner may exercise on his land which would not affect the other owners. If he builds a building, that building may block the sun's rays or the air from the buildings next to it and owned by other people. And if he runs a business, the lands adjacent to that business may be overburdened with the accompanying noise or traffic. If oil is prospected in a land, the neighboring lands may be deprived of oil or their owners may be exposed to toxic fumes. Hence the importance of researching the intention of harming others, as it is one of the most important forms of abuse in the use of the right (especially
... Show MoreThis study was conducted to investigate the relationship between corticosterone hormone in the blood of local Iraqi white chicken mothers and the sexual ratio of the hatching chicks. A field experiment located at the Poultry Research Station, Livestock Department, Agricultural Research Department, Ministry of Agriculture for the period from 16 of September 2018 to 25 of December 2018. One hundred and forty birds of Iraqi local chicken mothers (100 females+ 40 males) at the age of 28 weeks were provided from the poultry research station. The birds were raised in individual cages and distributed sequentially to the cages after the numbering of the females. Data were recorded in three periods, each period was of 28 days, and then the general a
... Show MoreThe aim of this study is to explain methods to be followed for the recovery Alsnav Hor, who represents the northwest portion of the Hammar Marsh in the province of Dhi Qar, after the drought in which that happened in 2008. The study included description of the region before the drought, the description of its natural and human environments, the economic events and activities, then the study included drought throughout the region, the environmental impacts caused by drought, its impact on social reality, economic and healthy for its environment, and then reached to the problems of social and economic in the region, depending on the Field studies and documented in the specialized government departments, information analysis for the
... Show MoreThe research aims to apply the activities of the green value chain as one of the modern administrative techniques that economic units resort to develop solutions to the pollution problems that occur due to the activity of economic units and their products that may cause damage to the environment as well as the waste of natural resources and to identify the production of environmentally friendly products and reduce the costs of environmental failure of both types Internal and external that may be borne by economic units such as taxes, fines and compensation due to non- observance of environmental requirements and the preservation of human health and protection of the environment.To achieve the goal of the research, the researchers re
... Show MoreRecent studies agree that the democratic system in a country can only be established in an atmosphere of political and religious freedom. However, the term democracy and the term freedom have become controversial because their concepts remain multiple and different. Karl Popper is one of the most prominent philosophers in modern Western political thought, and one of the defenders of democracy as opposite to dictatorship. It has defined its function by its ability to restrain the ruling elite and to enforce it to prevent their tendency to tyranny. This can be achieved only in the context of the close relationship between democracy and freedom, so, if there is democracy in the absence of absolute freedom, democracy is a gateway to expandin
... Show MoreThis research paper is about synoptic climate specifically with in the upper air layers
using upper air layers maps analysis which are maps of thickness for the level 1000 – 500
MB, that their high average ranges between 100 – 5600 M above surface. This research paper
focuses on studying special and temporal variations of the atmosphere thickness above Iraqaccording
to this study, it is concluded that atmosphere thickness above Iraq increases
towards south with an average of 100 M as compared with north of Iraq. Regarding the
temporal variations, it is concluded that atmosphere thickness during hot months. In July, for
example, the atmosphere thickness becomes thicker than in January with an average of
(250)M
Construction projects have a special nature and affect them many factors making them exposed to multiple risks as a result of the length of the implementation period and the multiplicity of stages, starting from the decision stage through implementation until the final delivery, which leads to increased uncertainty and the likelihood of risk.
The process of analysis and risk management is one of the effective and productive methods that are used in managing the construction projects for the purpose of increasing the chances of ending the project successfully in terms of cost, time and quality and at the lowest possible problems.
The research aims first to the effective planning for analysis and risk managemen
... Show More