Electromechanical actuators are used in a wide variety of aerospace applications such as missiles, aircrafts and spy-fly etc. In this work a linear and nonlinear fin actuator mathematical model has been developed and its response is investigated by developing an algorithm for the system using MATLAB. The algorithm used to the linear model is the state space algorithm while the algorithm used to the nonlinear model is the discrete algorithm. The huge moment constant is varied from (-3000 to 3000) and the damping ratio is varied from (0.4 to 0.8).
The comparison between linear and nonlinear fin actuator response results shows that for linear model, the maximum overshoot is about 10%,
... Show MoreThe present study aims to identify the most and the least common teaching practices among faculty members in Northern Border University according to brain-based learning theory, as well as to identify the effect of sex, qualifications, faculty type, and years of experiences in teaching practices. The study sample consisted of (199) participants divided into 100 males and 99 females. The study results revealed that the most teaching practice among the study sample was ‘I am trying to create an Environment of encouragement and support within the classroom which found to be (4.4623). As for the least teaching practice was ‘I use a natural musical sounds to create student's mood to learn’ found to be (2.2965). The study results also in
... Show MorePure cadmium oxide films (CdO) and doped with zinc were prepared at different atomic ratios using a pulsed laser deposition technique using an ND-YAG laser from the targets of the pressed powder capsules. X-ray diffraction measurements showed a cubic-shaped of CdO structure. Another phase appeared, especially in high percentages of zinc, corresponding to the hexagonal structure of zinc. The degree of crystallinity, as well as the crystal size, increased with the increase of the zinc ratio for the used targets. The atomic force microscopy measurements showed that increasing the dopant percentage leads to an increase in the size of the nanoparticles, the particle size distribution was irregular and wide, in addition, to increase the surfac
... Show MoreBulk AlxSb1-x samples were prepared with different x ratios (0.1, 0.3, 0.5, 0.7 and 0.9) by quenching technique. This was done throughout mixing the aluminum and antimony elements according to the proper atomic weight and put them in an evacuated quartz ampoule which then sealed and heated at 1273 K for five hours and left to cool in air. Thin films of AlxSb1-xwere prepared by using thermal evaporation under vacuum of 10-5 mbar on glass substrates at room temperature with deposition rate (10-15nm/min) at thickness of ∼ 500nm. The structures of AlxSb1-x bulk and thin films have been studied by X–ray diffraction technique. The results showed that all alloys have polycrystalline structures and the p
Shapes have differed in terms of their temporality, tools, technical variations, aesthetic functions and dimensions. The beginnings started with manual primitive techniques that have played an a significant artistic role in the ancient civilizations, then developed with the technological development and the digital technologies that encompassed various programs and specialist means in the graphic design, so that its visual outputs in the textbook that is considered a communication means that has an effect and attracts the recipient. That is what made the researcher search and investigate this topic describing the research problem as follows: What are the shapes as alternatives to the words in the design of the textbook? The research obje
... Show MoreTo study the response of the celery plant to nitrogen fertilization and spray with salicylic acid in the leaves content of nutrients, the research was conducted in one of the fields of the Department of Horticulture and Gardening Engineering / College of Agriculture / University of Baghdad within the 2019-2018 season. The research was carried out as a global experiment and with the design of complete randomized sectors (RCBD) and with three replicates, the first factor included the addition of nitrogen with three levels and its symbol (N) (N1 control), (N2) g / m2 18 ), (N3) 37 g / m2 and the second factor spraying acid salicylic is denoted by