title: Effect of acid solutions on plants studied by the optical beam deflection method.
abstract: The optical beam deflection method was applied to study the effects of acid solution on both a terrestial and aquatic plants Egeria and Cerastium, which are common aquatic plant and terrestial weed respectively. A probe beam from a He-Ne laser was passed through a vicinity of a leaf of the plants, which were put in culture dishes filled with acid solutions. Deflection signals of the probe beam were monitored and compared for acid solutions with different pH values. The results of Egria showed that the deflection signals changed dramatically when pH values of acid solutions were 2.0 and 3.0, while little at pH of 4.0 and 5.0. For Cerastium when pH were below 3.0, deflection signals changed greatly with time at the begining. After a certain period of time, deflection signals changed little with time. When pH value was above 4.0, deflection signals of Cerastium were still changing with time even after 20 hours. The results suggested that the damage threshold of pH was between 3.0 and 4.0 for both the land and aquatic plants.
authors: Department of Life, Environment and Materials Science, Fukuoka Institute of Technology3-30-1, Wajirohigashi, Higashi-ku, Fukuoka 811-0295, Japan.  mbm12007@bene.fit.ac.jp
authors: Liangjiao
authors: L
authors: Nie
authors: Department of Materials Science and Engineering, Graduate School of Engineering, University of Fukui, Bunkyo 3-9-1, Fukui-shi 910-8507, Japan.
authors: Mitsutoshi
authors: M
authors: Kuboda
authors: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.
authors: Tomomi
authors: T
authors: Inoue
authors: Department of Life, Environment and Materials Science, Fukuoka Institute of Technology3-30-1, Wajirohigashi, Higashi-ku, Fukuoka 811-0295, Japan. Electronic address: wu@fit.ac.jp.
authors: Xingzheng
authors: X
authors: Wu
mesh_terms: D000143:Acids / Q000494:pharmacology*; D029748:Caryophyllaceae / Q000187:drug effects*; D031321:Hydrocharitaceae / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration; D055095:Optics and Photonics / Q000379:methods*; D012815:Signal Processing, Computer-Assisted; D012996:Solutions
chemical_list: D000143:Acids; D012996:Solutions
keywords: Cerastium; Egeria; acid rain; optical beam deflection; plant