DESIGN AND IMPLEMENTATION OF NOMINAL CHARACTERISTIC TRAJECTORY FOLLOWING (NCTF) CONTROLLER FOR LINEAR MOTION SERVO SYSTEM

The current mechanical engineering era in the field of air-conditioning technology require students that are able to master the skills of air-conditioning completely, from basic fundamental knowledge to the craftsmanship applications. The air-conditioning technology had became an important field of study due to the geographical location of our country with year round temperature of 35°C. Therefore, an  air-conditioning simulator is produced for the purpose of laboratory teaching and learning that is able to translate the concepts of air-conditioning cycle easily.

ANNULAR DISTRIBUTOR FOR FLUIDIZATION

Fluidization is the operation by which solid particles are transformed into fluidlike state through suspension in a gas or liquid. This method of contacting between solid and fluid has some unusual characteristics, and fluidization engineering puts them to good use A large number of industrial processes use the fluidization technique in their daily operation, namely combustion, gasification of solid fuels, drying of particles, particle heating, oxidation, metal surface treatments and catalytic and thermal cracking.

One of the recent developments in providing a variant in fluidized bed operation is the swirling fluidized bed. In contrast with conventional fluidization, a swirling fluidized bed imparts swirling motion to the bed particles. In the current work, the fluidized bed features an annular bed, angular injection of gas and swirling motion of bed material in a circular path will be studied. The principle of operation is based on the simple fact that a horizontal component of gas velocity in the bed creates horizontal motion of bed particles. A jet of gas enters the bed at an angle θ_b to the horizontal. Due to angular injection, the gas velocity has two components. The vertical component U_v = U sin θ_b, causes lifting of particles. It is this lifting force that is responsible for fluidization. The horizontal component U_h = U cos θ_b, creates a swirling motion of the particles. The bed particles are also likely to undergo a secondary motion in a toroid-like path and be well mixed in the radial plane.

This variant of fluidized bed provides an efficient mean of contacting between gas and particles. Apart from that, elutriation of particles which has always limited the operation of a conventional fluidized bed is reduced significantly, since the vertical component of velocity is now small fraction of the net gas velocity. The cyclone-like features resulting from the swirling motion of bed particles may also contribute to this low elutriation. Hence it is possible to fluidize very fine particles and a wide variety of shapes of particles in this kind of fluidized bed.

THE SEARCH FOR RELEVANT FACTORS OF PROFESSIONAL LEARNING ON THE JOB OF VOCATIONAL INSTRUCTORS IN MALAYSIA’S TECHNICAL AND VOCATIONAL INSTITUTIONS.

This paper describes two studies into the professional learning of vocational instructors in workplace learning. The first study aimed at developing a definition of professional learning at the workplace and at exploring factors that may affect vocational instructors learning at the workplace. Based on a conceptualization of vocational instructors workplace learning as participation in professional learning activities, the second study addressed two research questions  answered by means of a survey: 1) To what extent do vocational instructors participate in professional learning activities? and 2) What factors affect this participation? Results revealed great discrepancies between theory and practice in opportunities for professional learning at the workplace. From these findings the criteria is drawn and recommended as the conceptual framework of Professional Learning On Demand Model of vocational instructors in Malaysia’s Technical and Vocational Institutions.