by Sumeth Naorungrote(Walailak University, Nakhon Si Thammarat (Thailand). School of Science. Natural Resources Utilization Unit), Warangkana Chunglok(Walailak University, Nakhon Si Thammarat (Thailand). School of Allied Health Sciences and Public Health), Monthon Lertcanawanichakul(Walailak University, Nakhon Si Thammarat (Thailand). School of Allied Health Sciences and Public Health), Phuwadol Bangrak(Walailak University, Nakhon Si Thammarat (Thailand). School of Science. Natural Resources Utilization Unit) E-mail:bphuwado@wu.ac.th
Published in Walailak journal of science and technology (01.11.2011)