Static loads exposing to mechanical components can cause cracks, which are lead to form stress concentration regions causing the failure of structure. Generally, from 80% to 90% of structure failure is due to initiation of the cracks. Therefore, it is necessary to repair the crack and reduce its effect on the structure where the effect of the crack is modelled as an additional flexibility to the structure. In the last few years, piezoelectric materials have been considered as one of the most favourable repairing techniques. The piezoelectric material converts the applied voltage on it to a bending moment to counter the bending moment caused by the external load on the beam at the crack location. In this study, the design of the piezoelectric materials used to repair effect of crack on the mechanical behaviour of beam subjected to static loads is analytically achieved. This design includes calculating of desired dimensions of the material with the required voltage applied on it. The additional flexibility is expressed in term of a proposed unitless factor which can be calculated depend on experimental work. The results show that increasing the patch thickness increases the beam resistance to crack and load effects, while increasing the length of the piezoelectric material reduces the magnitude of the voltage required to repair the cracked beam.
In this paper all possible regressions procedure as well as stepwise regression procedure were applied to select the best regression equation that explain the effect of human capital represented by different levels of human cadres on the productivity of the processing industries sector in Iraq by employing the data of a time series consisting of 21 years period. The statistical program SPSS was used to perform the required calculations.
That the main feature of the economics many countries in general is a tendency towards defining the role of the public sector in economic activity and the tendency towards encourage the private sector to investment in public projects especially in countries those tendency towards market economy actually.
That increased economic development proven failure in achieving more economic growth both individually in many countries especially developing countries socialist, by researchers this led one way or another to direction of corrective reforms in their economic was one of them in Transformation of public companies into Shareholding companies contributes to the public sector in resources and expertise
... Show MoreSurvival analysis is one of the types of data analysis that describes the time period until the occurrence of an event of interest such as death or other events of importance in determining what will happen to the phenomenon studied. There may be more than one endpoint for the event, in which case it is called Competing risks. The purpose of this research is to apply the dynamic approach in the analysis of discrete survival time in order to estimate the effect of covariates over time, as well as modeling the nonlinear relationship between the covariates and the discrete hazard function through the use of the multinomial logistic model and the multivariate Cox model. For the purpose of conducting the estimation process for both the discrete
... Show MoreThe research aims to identify the obstacles facing the application of electronic management in our university libraries, including the central library of the University of Baghdad and the central library of Al-Mustansiriya University, the research sample, as they are among the main libraries that used electronic technologies in managing some of their work and in providing their services, and they have a website via the Internet. The research relied on the case study method to identify the obstacles by visiting the two libraries, interviewing their managers and employees responsible for the departments, and answering inquiries about the obstacles that prevent the application of electronic management in order to identify them and find appropr
... Show MoreRadiation is a form of energy, its emitted either in the form of particles such as α-particles and β-particles (beta particles including the electron and the positron) or waves such as sunlight, X-rays and γ-rays. Radiation found everywhere around us and it comes from many different sources naturally or man-made sources. In this study a questionnaire was distributed to people working in the field of X-rays that used for a medical imaging (X-ray and CT-scan) to evaluate the extent of awareness and knowledge in estimate the damage of ionizing radiation as a result of wrong use. The questionnaire was distributed to medical clinics in Al-Harithiya in Baghdad, which it’s considered as
The proposal of nonlinear models is one of the most important methods in time series analysis, which has a wide potential for predicting various phenomena, including physical, engineering and economic, by studying the characteristics of random disturbances in order to arrive at accurate predictions.
In this, the autoregressive model with exogenous variable was built using a threshold as the first method, using two proposed approaches that were used to determine the best cutting point of [the predictability forward (forecasting) and the predictability in the time series (prediction), through the threshold point indicator]. B-J seasonal models are used as a second method based on the principle of the two proposed approaches in dete
... Show MoreThe researcher is one of the workers in university sports student activities, as he noticed that there is a diversity in the use of leadership patterns among managers of student activities in Iraqi universities between one director and another, which leads to the impact of these leadership styles on performance, positive or negative, in the level of human relations and the achievement of results. The researcher adopted the descriptive method in the survey method with relational relationships. The research sample consisted of (184) sports coaches who represent (27) universities and governmental and private colleges. To achieve the research objectives, the researcher used the Statistical Package for Social Sciences (Spss). To extract.statisti
... Show MoreThe aim of this research is to construct a three-dimensional maritime transport model to transport nonhomogeneous goods (k) and different transport modes (v) from their sources (i) to their destinations (j), while limiting the optimum quantities v ijk x to be transported at the lowest possible cost v ijk c and time v ijk t using the heuristic algorithm, Transport problems have been widely studied in computer science and process research and are one of the main problems of transport problems that are usually used to reduce the cost or times of transport of goods with a number of sources and a number of destinations and by means of transport to meet the conditions of supply and demand. Transport models are a key tool in logistics an
... Show More This research aims to identify the economic design techniques and materials that can be used in the implementation of cosmetic supplements to the spaces of the dwelling. The research relied on the descriptive and analytical approach by describing and analyzing models of design techniques and materials that can be used in the production of cosmetic supplements in the interior spaces of the dwelling.
The results of the research concluded that the beautification of the spaces of the dwelling is one of the necessary and important pieces to add aesthetic touches to the internal spaces, and that the use of economic design techniques and materials contributes to the implementation of many pieces of complementary beautification of the
In the midst of conflicts different intellectual and knowledge of production processes and circulation we need constant search for different levels of Innovation replenished with renewed need to develop solutions to various problems. Amid this conflict comes to mind a question about what salt creative mechanisms act in Graphic Design? Through this research is marked (creative mechanisms act in Graphic Design) strive to find solutions
to this question, as well as cognitive it Sarphi side modern and developmental study to a broader understanding of the subject. And across four seasons, which included the first chapter of the research problem and the need for him, and then came the second chapter includes theoretical framework goal Bemb