This study focuses on the modeling of manufactured damper when used in steel buildings. The main aim of the manufactured dampers is to protect the steel buildings from the damaging effects that may result due to earthquakes by introducing an extra damping in addition to the traditional damping.
Only Pure Manufactured Dampers, has been considered in this study. Viscous modeling of damping is generally preferred in structural engineering as it leads to a linear model then it has been used during this study to simulate the behavior of the Pure Manufactured Damper.
After definition of structural parameters of a manufactured damper (its stiffness and its damping) it can be used as a structural element that can be added to a mathematical model of the structure. As the damping of manufactured dampers is generally greater than the damping of traditional materials, then the resulting damping matrix for the whole structure will be classified as a nonclassical damping. As most of literature on earthquake engineering have been written in terms of terminology related to mode superposition method and as this method is applicable to classical damping only. Then, this study tried to check the accuracy of the mode superposition method when applied to a structure with manufactured dampers. In this checking, approximated results of mode superposition method have been compared with more accurate results of direct integration method. From this comparison, it has been noted that the mode superposition method has different levels of accuracy depending on the relation between the fundamental
frequency of the structure and the dominate frequency of the earthmotion. If the frequency of the structure is approaching to a dominate frequency of the earthmotion, then the damping effect will be important and the difference between the direct integration method and the model superposition method is increasing and vice versa
As a result of the increase in wireless applications, this led to a spectrum problem, which was often a significant restriction. However, a wide bandwidth (more than two-thirds of the available) remains wasted due to inappropriate usage. As a consequence, the quality of the service of the system was impacted. This problem was resolved by using cognitive radio that provides opportunistic sharing or utilization of the spectrum. This paper analyzes the performance of the cognitive radio spectrum sensing algorithm for the energy detector, which implemented by using a MATLAB Mfile version (2018b). The signal to noise ratio SNR vs. Pd probability of detection for OFDM and SNR vs. BER with CP cyclic prefix with energy dete
... Show MoreIt’s an attempt to identify the cultural activities of the Ministry of Culture, Tourism and Antiquities, which are provided by the Ministry of Culture, Tourism and Antiquities and the departments affiliated with the Ministry of Culture only, not tourism and antiquities. The most important results areIs that the Ministry of Culture, Tourism and Antiquities has many cultural activities such as (festivals, exhibitions, conferences, fashion shows, concerts, musical evenings, theatrical and cinematic performances) in addition to literary series and cultural magazines, which are directed to the public in general, whether it is elite or not, and this shows the extent The importance of cultural activities published by the Ministry of Culture, Tou
... Show MoreA cantilevered piezoelectric beam with a tip mass at its free end is a common energy harvester configuration. This paper introduces a new principle of designing such a harvester which increases the generated voltage without changing the natural frequency of the harvester: The attraction force between two permanent magnets is used to add stiffness to the system. This magnetic stiffening counters the effect of the tip mass on the natural frequency. Three setups incorporating piezoelectric bimorph cantilevers of the same type in different mechanical configurations are compared theoretically and experimentally to investigate the feasibility of this principle. Theoretical and experimental results show that magnetically stiffe
... Show MoreThe importance of operational risks increases with the increase in technological development, the development of banking operations, the extent of banking compliance, and the attempt of many banks to achieve quality in banking services. And the extent of the position occupied by Iraqi banks for banking compliance and reducing operational risks. The Basel Committee (2) paid its attention to operational risks and the interest of international banks to follow policies that work to ensure banking compliance and cover operational risks, because of its role in reducing losses due to increased costs and achieving an increase in profits. Realizing and working to confront the best possible and traditional methods, that some risks Operational problem
... Show MoreThe research problem stems from the suffering of organizations from the weakness of their organizing aspect and the weak influence of the leadership on the subordinates and their dispersion. Organizations today are in rapid development and therefore work relations are not dominated by the humanitarian aspect and the first goal has become productivity. The research aims to identify the influence of servant leadership and its dimensions as an independent variable on the effectiveness of work teams as an approved variable and their importance increases when these organizations are service organizations, and how their influence increases when this leadership is the servant leadership and its dimensions in the Health Depa
... Show MoreThe present study deals with the effect of teaching speaking Strategies (SS) on
EFL Iraqi College students. The use of speaking strategies not only solves learners’
communication problems, but also enhances the learner’s interaction in target language,
and improves their oral proficiency .The aim of the study is to find out the effect of
teaching SS used by EFL College students .The learner of the first stage is population of
the study at the Department of English, College of Education /Ibn-Rushd .The sample
consists of (60) students distributed on experimental group(A) as well as control
group(B) each group contains (30) students . In order to achieve the aim of the study,
questionnaire has been constructed t
Optical spectrum of SN1987A at days 4 from the explosion and its light curve through the first 1444 days after the explosion have been studied. The hydrogen lines present in the spectrum confirms the general characteristics of Type II SN that occur due to core collapse of massive star. Each of the total mass ejected from the explosion and the amount of the total mass of Nickel radioactive isotopes that produced during the explosion as well as the initial velocity of the ejecta and the explosion energy have been determined and compared with different observed and calculated models obtained by different researchers and it’s found that, about 8.8 Mʘ of the progenitor envelope mass had been ejected during the explosion and it’s mixed with
... Show MoreThe objective of this paper is to study the stability of SIS epidemic model involving treatment. Two types of such eco-epidemiological models are introduced and analyzed. Boundedness of the system is established. The local and global dynamical behaviors are performed. The conditions of persistence of the models are derived.
The type of groundwater in the studied area is slightly brackish. In general, the dominant water type is calcium-sulfate. The reasons behind these different chemical groundwater types can be referred to the active ion exchange between the groundwater of the Dammam aquifer and Rus Formation. The groundwater of the Dammam unconfined aquifer is not suitable for human drinking in all the parameters properties. The groundwater class is fair in the Qasir Al-Ukhaider area, while the Shebcha area and Al-Salman area are poor class except the eastern part of Al-Salman area is very poor.