The PHILIPPINE ENGINEERING JOURNAL serves as a medium of exchange of technical information and dissemination of engineering knowledge through the publication of research articles, review articles, short communications, and letters to the editor. Published by UP National Engineering Center, the PHILIPPINE ENGINEERING JOURNAL is being distributed at reasonable rates to various government agencies, private industrial concerns, engineering schools, professional organizations, international entities, and practitioners in the field of engineering.

Prof. Maria Antonia N. Tanchuling, Ph.D.
Executive Director National Engineering Center

Dr. Rinlee Butch M. Cervera
Editor-in-Chief

EDITORIAL BOARD

Dr. Marjorie L. Baynosa
Dr. Ariel C. Blanco
Dr. Michael Angelo A. Pedrasa
Dr. Leslie Joy L. Diaz
Dr. John Richard E. Hizon
Dr. Iris Ann G. Martinez
Dr. Susan Pancho-Festin
Dr. Edwin N. Quiros
Dr. Analiza P. Rollon
Dr. Karl N. Vergel

INTERNATIONAL ADVISORY BOARD
Dr. Alias Abdul Rahman
Universiti Teknologi Malaysia, Malaysia

Dr. Joost Santos
George Washington University, USA

Dr. Jiro Takemura
Tokyo Institute of Technology, Japan

Dr. Chua-Chin Wang
National Sun Yat-Sen University, Taiwan

Dr. Jeffrey Rimer
University of Houston, USA

Dr. Po-Ya Abel Chuang
University of California Merced, USA

EXTERNAL ASSOCIATE EDITORS

Dr. Hongbo Cong
University of Akron, USA

Dr. Mary Lyn Lim
Coatings Innovation Center, USA

Dr. Aristotle Ubando
De La Salle University, Philippines

Arlene H. De Ocampo
Head, Engineering Information Division, National Engineering Center

Patricia M. Estopace
Publication Coordinator

Erwin G. Gabriel
Layout Artist