Abstract: A Manganese dioxide/Chitosan (MnO2/CS) composite was prepared by a simple solution mixing-reductionoxidation method. The structure and morphology features of the composite were characterized by X-ray diffraction, scanning electron microscopy (SEM) and Energy Dispersive X – Ray (EDX), Brunauer–Emmett–Teller (BET) surface area and Fourier Transform Infrared (FTIR). The results obtained from these analyses revealed that Chitosan was loaded by manganese dioxide nanoparticles which were smaller than 18 nm in size. The surface area of the solid material was found to be 15.7 m2.g−1, respectively. The resulting EDX spectra showed that there was about 0.1 gram MnO2loaded on 1.0 gram material. This MnO2/CS was utilized as adsorbent to remove Pb2+ions from aqueous solutions. Adsorption features of MnO2/CS composite were investigated as a function of initial pH, contact time and initial Pb (II) concentrations.For adsorption isotherms, the Sips isotherm model was provided to be the best correlation

• Publication Date: 12-Apr-2015
• DOI: 10.15224/978-1-63248-055-2-06
• Views: 0
• Downloads: 0

Abstract: Magic rectangles are a classical generalization of the well-known magic squares, and they are related to graphs. A graph G is called degree-magic if there is a labelling of the edges by integers 1, 2, ..., | E(G) | such that the sum of the labels of the edges incident with any vertex v is equal to (1 | E(G) |)deg(v) / 2. In this paper we generalize magic rectangles to be n -tuple magic rectangles, and prove the necessary and sufficient conditions for the existence of even n - tuple magic rectangles. Using this existence we identify the sufficient condition for degree-magic labellings of the n -fold selfunion of complete bipartite graphs to exist.

• Publication Date: 12-Apr-2015
• DOI: 10.15224/978-1-63248-055-2-07
• Views: 0
• Downloads: 0