The study of the laptop computer table is one of the important studies at the present time due to the importance of electronic computers that are used in work sites and homes for very long hours, so one of the most important basics of caring for the comfort of the user lies in the design of the laptop table in different shapes and sizes and multiple functions in addition to calculating the measurements of the human body and the extent Its compatibility with the design and measurements of laptop computer tables by taking into account the calculations and measurements of the dimensions of the user's body of all ages and their consistency and use with the general measurements of the tables and the importance of research comes through the establishment of a knowledge base covering the topic of research to be of benefit to designers and specialists in this field and of benefit to product users as this study is It included all aspects of the tables, and the aim of this study was: to find foundations for building the formal system for the laptop table to be more suitable for the user. As for the limits of the research, the study of the formal system for the laptop table of the Chinese company Havic and available in the Iraqi market during the year 2011-2012 This study contains four chapters, the first chapter includes the research problem and the need for it in addition to oh The amount of research and its objectives and limits. As for the second chapter, it included the previous studies and the theoretical framework, which in turn contained three topics, the first was titled Foundations of Building the Formal System for the Laptop Desk and it contained an overview of the laptop computer, the laptop table, the system, the shape, and the second topic was titled Multifunctionality of the Laptop Table The third topic is on the mechanism of the human body ergonomics and its relationship to the laptop table. And then this chapter ended with indicators. The third chapter includes research procedures and methodology, and includes description and analysis of sample samples according to the axes analysis form. Finally, the fourth chapter included the results of the analysis, conclusions, recommendations and proposals. 1. The design system was distinguished by the efficiency of the functional performance and it helped in that the flat and supportive surface of the table surface in addition to the mechanism of the movement of the legs up and down as well as laterally and this achieved a distinct performance aspect although there were no fans for cooling The laptop computer while working and this was achieved in Form No. (1) and the percentage was 50%, while Model No. (2) achieved higher efficiency in functionality due to the presence of fans and the percentage was 50% .2 The dimensions of the computer tables differed according to the user’s need, as they were voluntary To the user as he wants through the size of the table tops and its inclination mechanism in addition to controlling the height and drop of the table legs. 3 The interconnectedness between the design parts aims to influence the functionality in a good way and this was achieved through the use of appropriate fastening means for the mechanism of movement and movement of the table by 50%
This paper proposes a new structure for a Fractional Order Sliding Mode Controller (FOSMC) to control a Twin Rotor Aerodynamic System (TRAS). The new structure is composed by defining two 3-dimensional sliding mode surfaces for the TRAS model and introducing fractional order derivative integral in the state variables as well as in the control action. The parameters of the controller are determined so as to minimize the Integral of Time multiplied by Absolute Error (ITAE) performance index. Through comparison, this controller outperforms its integer counterpart in many specifications, such as reducing the delay time, rise time, percentage overshoot, settling time, time to reach the sliding surface, and amplitude of chattering in control inpu
... Show MoreThe performance of a solar assisted desiccant cooling system for a meeting-hall located in the College of Engineering/University of Baghdad was evaluated theoretically. The system was composed of four components; a solar air heater, a desiccant dehumidifier, a heat exchanger and an evaporative cooler. A computer simulation was developed by using MATLAB to assess the effect of various design and operating conditions on the performance of the system and its components. The actual weather data on recommended days were used to assess the load variation and the system performance during those days. The radiant time series method (RTS) was used to evaluate the hourly variation of the cooling load. Four operation modes were employed for perform
... Show MoreThe effect of substitution of Ni on Cu in (Bi0.8Pb0.2)2(Sr0.9Ba0.1)2 Ca2Cu3-x Nix O10+? for (x=0,0.1….1,2,3) superconductor system and sintering time has been investigated .The samples were prepared by solid-state reaction methods. The results show that the optimum sintering temperature is equal to 850 ºC, and the sintering time is equal to 140 h. The highest transition temperature (Tc) obtained for (Bi0.8Pb0.2)2(Sr0.9Ba0.1)2 Ca2Cu3-x NixO10+? composition was 113 with x=0.8 Phase analyses of the samples by X-ray diffraction (XRD) analysis showed an orthorhombic structure with a high Tc phases (2223) as a dominant phase and low Tc phase (2212) in addition to some impurity phases.
Throughout the centuries, several incidents of mercury toxicity have been reported. Mercury is found in many industries such as battery, thermometer and barometer manufacturing, in the agricultural industry is used in fungicides and in medicine, mercury is used in dental amalgams. An important mechanism involved in cellular injury is induced by exposure to different forms of mercury involves in the induction of oxidative stress. This study was conducted on non-smoker, male working in a chloroalkali plant for different periods, all workers were not suffering from chronic disease. Healthy non-smoker males that are not exposed, matched age were used as controls(C), workers aged (22-61) years, they were di
... Show MoreThis work aims to analyse the dynamic behaviours of the forest pest system. We confirm the forest pest system in plane for limit cycles bifurcating existence from a Hopf bifurcation under certain conditions by using the first Lyapunov coefficient and the second-order of averaging theory. It is shown that all stationary points in this system have Hopf bifurcation points and provide an estimation of the bifurcating limit cycles.
The aim of this work is to calculate the one- electron expectation value of the electronic charge of atomic system Z=2,3….7 and we compare with He atom . the electronic density function D(r1) of He atom and like ions are evaluated . using Hartree –Fock wave.