Construction And Testing Of Ultrasonic Bird Repeller

The threat posed by birds to economic crops in the farms or at storage facilities requires the deployment of an effective bird deterrent in such locations.  Many attempts have been made to develop successful bird deterrent systems with only a few achieving desired results. The ultrasonic frequency range 15-25 kHz is known to be disturbing to birds and a device operating at that range was developed. The output of the integral oscillator was fed to 4 piezo transducers, placed 90O to each other to produce a dispersion of overlapping fans of sound for full 360o coverage. The power of the first device was 7.98W and the intensity of the sound pressure at 1m was calculated to be 6.35x10-1W/m2 at 118dB. A second device was constructed which had a power of 23.98W and intensity of the emitted sound at 1m, 1.91W/m2 at 123dB. The devices were tested and the results obtained showed that the ultrasonic beam from the piezo speakers was able to drive birds away from designated areas. Further tests conducted with the unit showed a wider reach of the waves on a dull day than on a sunny day. About 5-6 of the second device is expected to cover one hectare of field. The device is solar powered, eliminating the cost of fuel, the inconvenience of regular attention and its protection from environmental perturbation. It is environmentally friendly. Keywords: Pest birds, Bird repeller, Solar powered, Ultrasonic, Frequency range, Environmentally friendly

Modeling of 2-D Computer Aided Drafting Application for Teaching and Learning Engineering Drawing

With non-availability of the required equipment, teaching engineering drawing to a class of over 1000 students and retaining their interests and attention from the beginning to the end of a lecture period was of big concern to the engineering drawing courses lecturers in the Faculty of Engineering, Nnamdi Azikiwe University, Awka. This work is aimed at designing and developing animated Microsoft Office PowerPoint teaching applications named 2-D Computer-Aided Drafting Applications (2-D CADA) that eliminate this problem. This paper presents a sample of the Applications which demonstrates clearly to the audience’s pleasure how to mount, set and hold a drawing sheet on a drawing board before actual drawing commences. It also shows how to manually draw boarder lines on the drawing sheet. Similar programs can be written and used to show to engineering students how to manually draw most of the figures specified in their schools' curricula using engineering drawing instruments. Many of this Application have been written on various topics in engineering drawing in line with the global trend of drudgery reduction in man-machine systems. These Applications are already being deployed in teaching engineering drawing in the Faculty of Engineering, Nnamdi Azikiwe University, Awka, Nigeria. The benefits of employing 2-D CADA in teaching and learning engineering drawing are overwhelming. 2D-CADA relieves a teacher the mental and physical stresses that go with manual production of drawings on a chalk board. It drastically improved the attention, interest and understanding of students during drawing lessons. A well written 2D-CADA can be replicated and deployed to a personal computer for self-study plans as well as to group-based students’ workstations for group teaching