His kanji name is 坂井純. He was a professor emeritus of
Kyushu University in Fukuoka Prefecture. Unfortunately, he passed away on June 8, 2015 at the age of 83.
■【訃報】坂井純氏(九大名誉教授) | 週刊「農機新聞」
(all in Japanese)
I don't know if it's still available or not, but you can find his e-mail address on his home page.
Dr.Sakai ???ȵ???
(click on 坂井先生へE-MAILする。)
his profile
1969-1971:ユネスコ国連専門家、 フィリピン セントラルルゾン州立大学(CLSU)
an expert in UNESCO, Central Luzon State University(CLSU), Philippines
?v???t?B?[??