Bacteriological quality of some ready to eat vegetables as retailed and consumed in Sabon-gari, Zaria, Nigeria

Some ready to eat leafy vegetables on sale at Sabon-gari market, Zaria were analysed for their bacterial flora and counts. Lettuce had aerobic plate count range of 2.0 x 107 to 5.7 x 108 cfu/g, cabbage had a count range of 1.3 x 107 – 5.6 x 108 cfu/g and cucumber had a range of count of 3.0 x 105 to 1.9 x 106. The coliform index showed lettuce to have a count of 8.8 x 106 – 1.3 x 109, cabbage was 2.1 x 106 to 8.0 x 107 cfu/g and cucumber was 8.0 x 105 to 1.9 x 106. Bacillus species and Staphylococcus aureus were the predominant bacteria isolated from these vegetables. The counts were obviously above the recommended standards for ready to eat vegetables especially coliforms which should be less than 10 coliform bacteria per gram( FAO, 1979). There is the need for hygiene officials to take interest on what is offered to consumers and specify acceptable handling practices

Effect of Coolant Temperature on Machining Characteristics of High Carbon Steel

This paper reports on the effect of coolant temperature on machining of high carbon steels. The development of a cooling system to reduce the temperature of water soluble coolant to 7.9oC from ambient temperature was employed in this work to improve the machining performance. The experiments were performed using cooled and ambient temperatures by employing Taguchi L18 orthogonal array to design the experimental runs. The cutting speed, feed rate and depth of cut were the machining parameters used; while the tool-work piece interface temperature was monitored using a digital thermometer with k-type thermocouple wire. The selected control factors are material removal rate and surface roughness. The experimental results were analyzed using Minitab 16. The main effects and percentage contributions of various parameters affecting surface roughness and material removal rate were discussed, and the optimal cutting conditions were determined. It was observed that surface finish improved by 65% with the use of the developed cooled system. The reduction in coolant temperature played a vital role in improving surface finish during machining high carbon steels

Deterministic Model for Noise Dispersion from Gas Flaring: A Case Study of Niger – Delta Area of Nigeria

Noise is an audible acoustic energy that adversely affects the health, physiological and psychological well being of the individuals or populations. One of the major pollutants from gas flaring is the noise emanating from gas flaring stations in the Niger – Delta area of Nigeria. Noise dispersion produces many adverse effects on man and animals. Experimental analysis of noise dispersion and weather conditions used for simulation has been carried out, the modeling and simulation of noise dispersion from flare stations using visual basic programme is the main focus of this work. Results obtained shows some variation between the simulated results and experimental results, with correlation coefficient ranging from 0.955 – 0.995. Simulation results of the developed model show that the noise intensity level reduces with increasing in distance from the flare point and that weather conditions has an important influence on noise dispersion

Toxicological Implication of Zinc Oxide Nano-Particles on Nutritional Composition and Depuration Potential of Heterobranchus longifilislis

Zinc Oxide nano-particles (ZnO-NPs) are more useful in the production of commercial goods than other nano-particles because of their unique properties. The effluents of ZnO-NPs get into the aquatic ecosystems and accumulate in fish tissues causing serious health consequences. This study was therefore designed to investigate the effect of ZnO-NPs exposure on the nutritional composition and depuration potential of large African catfish (Heterobranchus longifilis). The nutritional composition evaluated include, proximate composition, mineral content, fatty acids and amino acids profiles after exposing to varying (0.0, 6.00, 8.00, 10.00, 12.00 mg/l) concentrations of ZnO-NPs to juveniles’ catfish (H. longifilis) for 60 days and depurating for 30 days to evaluate recovery using standard methods. The results revealed that proximate composition and amino acid profiles decreased significantly (P < 0.05) after 60 days of exposure to ZnO-NPs, but gradually improved after 30 days of depuration. This implies that ZnO-NPs has a great influence on the nutrient values of H. longifilis, but the fish were able to regain the lost nutrients, however, the ability of H. longifilis to recover from adverse condition is time dependent

Preparation and Evaluation of Electrical Properties of Plastic Composites Developed from Recycled Polystyrene and Local Clay

In this study, the development of polymer composites was achieved from local clay material and waste polystyrene by cold pressing method, the preparation, electrical, and physical behaviours of clay-polystyrene composites are described. Polystyrene based resin (PBR) was produced from waste polystyrene by solvolysis in petroleum solvent and mixed with the 100μm clay particles at 10%, 20%, 30%, and 40% clay contents. Composite panels were prepared and tested for Physical and electrical properties. Metallurgical microscope was used for the microstructural studies. It was found that with the increase in clay content in PBR from 0 to 40%, there was a rise in density of the composite by about 11% with a simultaneous decrease in the void fraction or porosity from 5.3 % to 1.5%. It was also observed that the polymer composite with the filler loading of 40 wt% has the highest conductivity value of 1.88E-07 S/cm. The comparison of micrographs at 40x and 100x indicated a good dispersion and distribution of clay particles in the polystyrene matrix. The polymer composites produced can be adapted for applications where electrostatic dissipative materials are required.KEYWORDS: Electrical property, iron fillings, plastic composite, recycled polystyrene, clay particles