Determination of thermal properties of some ceiling material commonly used in Ijebu- Ode, Nigeria

The study investigates the thermal properties of different insulating material used in building construction in Ijebu Ode, a tropical rainforest region, south western, Nigeria. Five insulating material; asbestos, Plaster of Paris (P.O.P), PolyVinyl Chloride (PVC), hardboard and paperboard, were subjected to thermal investigation using Lee’s disc electrical method. The result obtained showed that the thermal conductivities obtained are within the range of values specified for good insulating materials. Asbestos was found to be associated with the least thermal conductivity of the value . --while PVC had the highest thermal conductivity values of . --. This may be associated with the temperature and the heat flux on the surface of the material. The results obtained for thermal conductivity, thermal resistivity and thermal diffusivity correlated favourably when compared with those of previous work from other locations. Asbestos being the material with the lowest thermal conductivity is therefore recommended for use as the suitable insulating ceiling material in the study area. Keywords: thermal conductivity, diffusivity, resistivity, Lee’s dis

Extraction of lycopene with cell wall degrading enzymes from tomato (Lycopersicon esculentum Mill) fruits deteriorated by Aspergillus niger

Lycopene is the carotenoid which gives tomatoes and other red fruits their characteristic colour. It is one of the most powerful antioxidants and singlet oxygen quenching agents. It has been found to be of great medical importance with various anticancer effects and its ability to ameliorate several other medical conditions. Freshly ripe tomato fruits of the Roma vf variety and the Ibadan local variety were allowed to deteriorate after infection with a 96-hr-old culture of Aspergillus niger. Extraction of cell wall degrading enzymes produced during the deterioration process was carried out ten days after inoculation of the tomato fruits. The crude enzymes were precipitated using ammonium sulphate precipitation technique and employed in the extraction of lycopene from tomato peels. The yield of lycopene was 45.25mg/kg and 45.86mg/kg for enzymes extracted from the Roma vf and the Ibadan local varieties of tomato fruits respectively. This study established an improvement in lycopene extraction with crude preparation of cell wall degrading enzymes and compared the yield from the two enzymes obtained from the two most commonly available varieties of tomato fruits in Nigerian markets