Size-Related Evaluation of Unburned Carbon

The unburned carbon (UBC) content of ash from coal-fired thermal power stations and plants that use massive amount of coal can sometimes be 6-7% or more; this simply means loss of carbon and decrease in efficiency. Carbon loss not only causes a decrease in efficiency but is also an economical issue. Decreasing the carbon content would provide the usage of ash from thermal power stations as cement additives. Many factors cause low combustion efficiency and a high amount of UBC. In the course of this study, fly ash and bottom ash were divided into size fractions and accumulation of UBC at coarser size fractions was observed. In this study, a ground coal sample from a mill was sieved, and the accumulation of UBC at coarser size fractions was associated to a lack of grinding of pulverized coal. Ground coal has a size distribution where 54.45% was below 75 µm, and 45.55% was still over this critical size. A significant amount (35.48%) of the UBC accumulated in the size fraction over 75 µm in fly ash, whereas almost 70% accumulated in the size fraction over 0.5 mm in bottom ash. Coal and ash samples were observed under a microscope to deduce origins of UBC. © 2016 Taylor & Francis

New soluble coordination chain polymers of nickel(II) and copper(II) ions and their biological activity

A new tetraoxime ligand, (2E, 3E, 9E, 10E)-1, 4, 8, 11- tetraazacyclotetradecane-2, 3, 9, 10-tetrone tetraoxime has been prepared by the template condensation of 1,3-propanediamine and cyanogen-di-N-oxide, obtained by treating (E, E)-dichloroglyoxime in CH 2 Cl 2 with Na 2 CO 3 at -10 °C. The coordination chain polymers {[(pnngH 2 ) 2 Ni] n (5) and [(pncgH 2 ) 2 Cu] n ( 6 )} of two transition metal ions, [Ni(II) and Cu(II)] with the vic-dioxime ligand have been prepared. The oxime ligand acts as a polydentate ligand bending through nitrogen atoms in the presence of a base, as do most of the vic-dioximes. In the complexes, the chloride ions coordinate to the nickel and copper ions. The structures of these novel vic-dioxime compounds are proposed on the basis of the elemental analyses, molar conductance data, i.r., and U.v.-visible are presented. Elemental analyses indicate a ligand metal ratio of 1:1 in the coordination polymers. Conductivity measurements have shown that mono- and polynuclear complexes are non-electrolytes. In addition, anti-microbial activities of the compounds have been investigated. © Springer 2005.We thank the Research Fund of Kahramanmara·s Süt-c¸ ü İmam University for financial support