The study was carried out to determine soil organic matter content (SOM) using loss on ignition (LOI) and titrant methods. Eighty-four composite samples were collected from surface of randomly different locations in four governorates northern parts Iraq. percent mean values SOM recorded 2.34, 2.399 1.821, respectively for Erbil, Sulaymaniyah, Kirkuk, Duhok the LOI method, while lower obtained 1...

As a mono-sodium salt form of alendronic acid, alendronate sodium presents multi-level ionization for the dissociation of its four hydroxyl groups. The dissociation constants of alendronate sodium were determined in this work by studying the piecewise linear relationship between volume of titrant and pH value based on acid-base potentiometric titration reaction. The distribution curves of alend...

We tested whether mixotrophic ciliates are more resistant to solar ultraviolet radiation (UVR) than heterotrophic ones because symbiotic algae can provide self-shading by cell matter absorption and eventually by direct UV screening from mycosporine-like amino acids (MAAs). Sensitivity of a natural assemblage to solar radiation was tested in experiments in the original lake and in a more UV tran...

The fission yeast Schizosaccharomyces pombe switches mating type by transposition of a copy of DNA derived from either of the two storage cassettes, mat2 -P and mat3 -M, into the expression locus, mat1 . The recombinational event of switching is initiated by a double-stranded DNA break present in approximately 20% of the molecules at mat1 . Fifty-three mutants defective in switching of mating t...

Manganese-oxidizing bacteria in the aquatic environment have been comprehensively investigated. However, little information is available about the distribution and biogeochemical significance of these bacteria in terrestrial soil environments. In this study, stratified soils were initially examined to investigate the community structure and diversity of manganese-oxidizing bacteria. Total 344 c...

2.1 Relationship between Oxidizing Power of Chlorine and Sodium Hypochlorite Many consumers are currently replacing chlorine with sodium hypochlorite as the oxidizing agent. In order to calculate how much sodium hypochlorite is required to replace the oxidizing power of chlorine, the following example is provided. If sodium hypochlorite is used to oxidize iodide in a solution of acetic acid, th...