African Journals Online
Journal of Applied Sciences & Environmental Management

Volume 7 Number 1 2003
Abstracts

Enzymes and fungal virulence

Tonukari, N J

International Livestock Research Institute, P.O. Box 30709, Nairobi, Kenya. Tel: 254-2-630743, Fax: 254-2-631499, E-mail: [email protected]

Abstract: This paper presents a comprehensive literature review of cell wall degrading enzymes (CWDEs). Plant pathogenic fungi secrete extracellular enzymes that are capable of degrading the cell walls of their host plants. These CWDEs may be necessary for penetration of the cell wall barrier, as well as for generation of simple molecules that can be assimilated for growth. Most of these enzymes are substrate-inducible and both specific and global regulators control their expression. CWDE-inhibitors have been isolated from plants and some evidence indicates that they are components of general resistance. ©JASEM

Stimulation of Growth and Development of Celosia argentea L. by Crude Extracts of Senna alata (L.) Roxb

*Agbagwa, I O; Onofeghara, F A; Mensah, S I

Department of Plant Science and Biotechnology, University of Port-Harcourt, P.M.B 5323, Port-Harcourt, Nigeria.

Abstract: The effects of different concentrations of Senna alata crude water extracts on the germination, growth and flowering of Celosia argentea were studied. All concentrations of this extract induced a consistent decrease in absolute percentage and rate of germination, and inhibited radical elongation in Celosia argentea. Earliness in flowering and overall increase in height was obtained from seedlings sprayed with 75⁰/₀ C and 100% C crude water extracts. ©JASEM

Efficacy of Catalysts in the Batch Esterification of the Fatty Acids of Thevetia Peruviana Seed Oil

^*Oluwaniyi, O O; Ibiyemi, S A

Chemistry Department, University of Ilorin, Ilorin, Nigeria.

Abstract: The methyl, ethyl, propyl and butyl esters of the fatty acids of Thevetia peruviana seed oil were successfully prepared by the batch-esterification procedures. Various acid catalyst and various molar ratios of fatty acid to alcohol were investigated. H₃PO₄ was found to be ineffective to catalyze the esterification of the free fatty acid. HCl gas and conc. H₂SO₄ both proved very effective in catalyzing the reaction. Concentrated H₂SO₄ however, proved better of the two acids. Three molar ratios 1:1, 1:3 and 1:10 were investigated, 1:3 molar ratio of the free fatty acid to the alcohol was found to be the most efficient. ©JASEM

Urinary and Anthropometrical Indices of Bone Density in Healthy Nigerian Adults

George, B O

Department of Biochemistry, Delta State University, Abraka, Nigeria

E-mail [email protected] 

Abstract: Measurements on the x-ray of the 2^nd metacarpal of the right hand and 2h fasting urine sample were used in a cross sectional study to assess urinary indices of bone density (bone mass, percentage cortical area, PCA) in 94 healthy Nigerian adults aged between 19-72 years. Body mass index (BMI) was also estimated. No significant gender - difference was observed in most of the parameters with exception of bone mass, which was larger in the males (57.11± 8.74 mm² and 47.40±8.43 mm² for males and females respectively, p < 0.05) and BMI, which was higher in the females (20.37± 2.61 and 22.56 ± 4.55, for the males and females respectively (p < 0.05). In both groups there was a significant association between urinary hydroxyproline and urinary calcium (r = 0.845, p < 0.001, and r = 0.412, p < 0.001) for females and males respectively. Urinary calcium and hydroxyproline was associated with age in the female (r = 0.530, p < 0.001) only. Bone mass correlated with urinary calcium in the males (r = -0.356, p < 0.05), while urinary hydroxyproline was inversely associated with PCA in the female group. Stepwise multiple regression analyses revealed that in this study, the best urinary and anthropometric determinants of bone mass were urinary calcium and height in the males, and weight and age in the females. Furthermore, urinary hydroxyproline was the best predictor of PCA in both male and female subjects. The relationships observed between BMI, age, urinary hydroxyproline, urinary calcium, and bone density indices suggest that these variables can be used to monitor or assess bone status in healthy individuals. ©JASEM

Treatment of Liquid Oil Spill by Untreated and Treated Aswanly Clay from Egypt

*¹Sayed, S A; El Sayed, A S; El Kareish, S M * ; Zayed, A M*

Dept. of Chemistry, Faculty of Science, Helwan University, Ain Helwan, P.No.11795, Cairo, Egypt.

Research Center, Misr Petroleum Company, Ghamra, Cairo, Egypt.

*Egyptian General Petroleum Corporation, Quality Control Dept., New Maadi, P.No. 11742, Cairo, Egypt

Abstract:The aim of this work is to use cheap, available and recyclable sorbents for oil spill clean – up. α -SiO₂-Quartz, Na₂Si₂O₅(OH)₄, CaCO₃, MgCO₃, BaCO₃, CaO, MgO, and Fe₂O₃ are used individually or mixed with Aswanly clay to identify the sorption activity of these materials and to show the effect of incorporation of these materials into the Aswanly clay. Results were 63, 75, 100, 93, 95,75, 92, 100, 80, 98, 90, 71, 90 and 97% on using 1.0 g α -SiO₂-Quartz, 0.9 g Na₂Si₂O₅ (OH) ₄, 0.07 g CaCO₃, 0.05 g MgCO₃, 0.08 g BaCO₃, 0.05g CaO, 0.1 g MgO, and 0.08 g Fe₂O₃, 0.1 g clay mixture of 50% CaCO₃, 0.1 g clay mixture of 10% MgCO₃, 0.1 g clay mixture of 50% BaCO₃, 0.1 g clay mixture of 50% CaO, 0.1 g clay mixture of 10% MgO, and 0.1 g clay mixture of 50% Fe₂O₃ respectively, to remove 14.07 mg crude oil, below which mechanical means for removing crude oil from oil contaminated water becomes less more effective, from oil contaminated water of volume 25 ml from oil contaminated water at pH 6 and temperature 30^oC. All of these materials were treated by naphtha, a petroleum product of boiling range 30^oC - 165^oC, to remove sorbed crude oil from its surface for further reuse and contaminated naphtha are processed to be distilled for reuse. Characteristics of crude oil and Aswanly clay were investigated by FTIR, X – Ray Fluorescence, X – Ray Diffraction, pour point and centrifuge instruments. Determination of amount of crude oil in water was done by extraction the crude oil with 10 ml n-hexane and measuring absorbance by UV – VIS. Spectrometer. ©JASEM

Assessing the Economic and Environmental Prospects of Stand-By Solar Powered Systems in Nigeria

Offiong, A

Department of Mechanical Engineering, Faculty of Engineering, University of Uyo, Uyo, Nigeria

Abstract: This paper presents an economic analysis of two stand-by power supply options for a typical Nigerian household namely diesel generator plant and solar powered systems. The analysis reveals that solar systems are the most economically viable. The environmental benefits associated with substituting diesel powered stand-by plants with solar powered photovoltaic systems were also estimated. The amount of diesel save was estimated and the reduction in air pollution calculated. With this two analysis it is hope that individual households in Nigeria, will be encouraged to go for solar stand-by systems while Government will be encouraged to pursue further an energy-environmental friendly policy which will lead to reduction in the production of air pollutants. This kind of policy is very essential, as the number of household installing stand-by power plants in Nigeria has been found to increase exponentially over the past few years. ©JASEM

Physico-Chemical Quality of Elechi Creek in Port Harcourt, Nigeria

*OBIRE, O¹; TAMUNO, D C²; WEMEDO, S A¹

¹Department of Biological Sciences, Rivers State University of Science and Technology

P. M. B. 5080, Port Harcourt, Nigeria

²Analytical Chemistry Department, Eleme Petrochemical Company Limited, Eleme, Port Harcourt, Nigeria

Abstract: A total of six hundred and sixteen (616) water samples were collected at seven stations from three zones (A, B, and C) of Elechi creek during an eleven-month's investigation. The samples were analysed for physico-chemical parameters including heavy metals. Higher concentrations of phosphate and BOD in zone B ranging from 2.3 to 9.0 ppm and 3.92 to 8.80 mgL^-1 respectively were observed and this reflects the eutrophic condition of the creek water in that zone. Concentrations of ammonia, total dissolved solids and salinity were higher in the dry season while those of sulphate, phosphate and electrical conductance were higher in the rainy season. Satistical analysis using analysis of variance (ANOVA) showed that, there were significant differences in concentrations of phosphate, total alkalinity, BOD, total dissolved solids, salinity and electrical conductivity at 5% level between the three zones of Elechi creek. These zonal differences were due to limited water exchange between the zones of the creek. The concentrations of heavy metals were generally low and no trends were observed along the stations of the creek. Except for iron (0.019 to 1.166 ppm) nickel (0.039 to 0.945 ppm) and zinc (0.002 to 4.345 ppm), the concentrations of the other heavy metals were within the range of less than 0.001 ppm to 0.718 ppm. The low concentrations of heavy metals may be due to lack of industrial discharges into the Elechi creek. ©JASEM

Extractability of Potassium from Some Organic Manures in Aqueous Medium and the Effect of pH, Time and Concentration

* Ako, P A E; Adebanjo, A S; Fadipe, A L; Ndamitso, M M

Department of Chemistry, Federal University of Technology, Minna, Nigeria

Abstract: The effect of pH, time and concentration on the extractability of potassium from five types of organic manures (cow dung, local chickens, duck and commercial chickens^, faeces on bedded and unbedded floor) were studied. Experiments were conducted in water at 40^oC. Cumulative extraction curves of potassium resulting from a 2-hour equilibration period indicated an initial fast process, the rate of which slowed down at later extraction numbers. Corresponding curves of extraction of the element as affected by selected factors showed that pH, concentration of the nutrient and equilibration time were important in influencing the readiness with which manures release potassiuim in aqueous medium. Individual character of each of the manures in releasing the element was also exhibited, but in general, the bedded floor commercial birds manures produced the highest rate, while duck and cow dung showed the least. The effect of the bedding material in enhancing the release of the nutrient from these manures is explained in terms of their relatively smaller particle size. The possibility of contribution to the nutrient resource of the manure by the material itself may be an additional factor. ©JASEM

Comparative Evaluation of the Effectiveness of some local Fabrics for Zooplankton Harvest

^1*Ovie, S I; ¹Azionu, B C; ²Ovie, S O ;¹Adepoju, F

¹ *Division of Environmental Studies, National Institute for freshwater, Fisheries Research, P.M.B.6006, New Bussa, Niger State, NIGERIA

² Federal College of Freshwater Fisheries Technology, P.M.B.1500, New Bussa, Niger State, NIGERIA

Abstract: A comparative evaluation of the effectiveness for zooplankton harvest for three local fabrics (a white poplin, 120mm; grey baft, 200mm; a nylon, 235mm) and an imported standard zooplankton net of mesh size 76mm were tested in this study. Mesh sizes and gauze constitution of the fabrics were determined with an ocular micrometer under a compound microscope. Filtration efficiency and clogging rates of the fabrics were also measured. All fabrics were effective in harvesting species of the copepods, the cladocerans and the large-sized rotifer, Asplanchna. The grey baft and the nylon net were not effective in harvesting the small-sized rotifer species like Keratella, Filinia and Trichocerca.All the fabrics effectively harvested Moina, an excellent freshwater cladoceran for fish larval-rearing. Clogging rate was found to be a function of gauze constitution, while filtration efficiency was an index of both gauze constitution and mesh size of fabrics. ©JASEM

The Environmental Impact of Oilfield Formation Water on a Freshwater Stream in Nigeria

* Obire, O; Amusan, F O

Department of Biology, Federal University of Technology, P.M.B. 704, Akure, Nigeria.

Department of Biological Sciences, R. S. U. S. T., P.M.B 5080, Port Harcourt, Nigeria.

Abstract: A comparative analysis of the physico-chemical parameters of treated oilfield formation water and that of a freshwater stream with no previous history of pollution from oil exploration activities was determined. The environmental impact resulting from the discharge of treated oilfield formation water into freshwater samples collected from this stream with no previous history of pollution from oil exploration activities was assessed in terms of changes in water quality parameters such as Dissolved oxygen (DO), Biochemical oxygen Demand (BOD) and in the microbial populations of the freshwater samples over a period of seven days since oilfield formation water readily mixes with flowing water after discharge. The analyses showed that concentrations of constituents such as chloride, total dissolved solids, total hardness, nitrate nitrogen and ammonium nitrogen alkalinity and silicate of the oilfield formation water were much higher than those of the freshwater source. The oxygen uptake (BOD values) in some stations of the freshwater stream differed significantly only at the 5% level after the treatment. Generally, the microbial populations were also lower after the treatment. Such observations suggest that, there is reduction in the biological activities of the freshwater after the addition of the treated oilfield formation water. ©JASEM