Fauziah Sulaiman

Design of high voltage and high frequency pulse generator by using DC choke

Pulsed Electric Field (PEF) processing has demonstrated a high potential for various applications ranging from extraction of valuable components from different biological objects to water treatment. Therefore, high voltage and high frequency pulse generator design is essential in order to fulfill the requirement of a PEF processing system. A high voltage and high frequency pulse generator using DC choke is proposed in this works as solution to increase the pulse train amplitude. The DC choke was verified using function generator to identify its operating frequency and voltage. Results showed that the operating frequency of the DC choke was between 24 kHz to 35 kHz and that it was able to retain the pulse shape of the input pulse train. These results show the ability of the DC choke as a potential solution to increase the pulse amplitude of a pulse train while retaining its shape and duty cycle by cascading it with other power topologies to produce high voltage and high frequency pulse generator for various applications.

Correlation of Students’ Perception after Project – Based Learning (Egg Drop Project) Intervention towards learning Physics

The purpose of this research was to identifythe correlation of students’ perception (i.e., personal interest, sense making and effort, real world connection and problem solving perception) in learning physics after the intervention of Project – Based Learning (PBL) (i.e., egg drop project). This research was conducted in Tuaran and Kota Maruduin Malaysia. A total of thirtyeight(38) form four students (i.e., 17 male and 21 female students) were used in the study. Data used in the study were collected using the Colorado Learning Attitude about Science Survey (CLASS) – personal interest, sense making, real world connection and problem solving general Category. Respondents were required to response to the survey instrument based on a five pointLikert scale after (post-survey)the implementation of PBL. Data collected were analysed using Statistical Package for Social Science Version 20.0 for windows (SPSS) to identify the correlation of students’ perception based on the post-survey responses. Spearman’s Rank – Order Correlation showed positive correlation between students’ personal interest, making sense and effort, real world connection and problem solving perception that includes overall students.Therefore study revealed that through PBL-egg drop project, students could relate physics concepts; momentum, impulse and impulsive force into real life situations, engaged students’ personal interest, sense making and effort, real world connection and problem solving perception and changed students’ perception towards physics.