[en] An LSC2 Liquid scintillation counter has been characterised using tritium, carbon-14 and background standards. The contribution of the background count rate has been investigated. The possibility of using the counter to measure aqueous solution has been studied. Although only 3-10% of aqueous solution can be incorporated into the two scintillators studied, the LSC2 scintillation counter can be used to measure low level tritium and carbon-14 in aqueous solutions

[en] Using thermal neutron activation analysis(NAA) technique, concentrations of over twenty elements were determined for ten vegetables commonly consumed in Zaria locality. Green vegetables, eaten raw or cooked in stew are essential part of local diet. Results of some of the trace element concentrations are; Titanium(460-80 ppm), Rubidium(123-27 ppm), and Cerium(10-2 ppm). Concentrations of the essential trace elements measured are Vanadium /5 - 1ppm/, Chromium /5 - 1ppm/, Manganese /0.7 - 0.1ppm), Iron /200 - 500ppm/, Cobalt /3.5 - 2ppm/. The result suggests no industrial pollution in the farm land

[en] A wall-less proportional counter that is suitable for radiocarbon dating has been developed. The counter consists of a central counter and an annular chain of twelve ring counters which are all enclosed in a cylindrical copper tube. Highly purified carbon dioxide is used as the counting gas and a chemical system designed for the purification of the gas is briefly described. The counter characteristics obtained with only tank gas as well as the purified gas are illustrated. They demonstrate the effect of electromagnetic impurities on the counter sensitivity and the significant background reduction achieved with the counter

[en] A method for performing shell-model calculations in a truncated Hilbert space is discussed. In particular it is shown that an exact effective interaction exists for any such truncation. The shell structure of 180 s shown as an illustrative example

[en] Band structure calculations for electron, heavy-hole and light-hole in the GaInAs/AlInAs MQW and SL system has been carried out using modified envelope function approximation model. Discrete levels (i.e. bound states) within the wells and discrete transmission resonances (i.e. virtual states) have been observed in each case. Calculated sub-band transition energies have been found to be in very good agreement with experimental measurements

[en] A parrafin neutron moderator was designed and constructed for a 5-Curie Am-Be isotope neutron source. The moderator is co-axial with the cylindrical source, while six irradiation positions are arranged symmetrically around the source. The maximum measured dose rate on the surface of the irradiation facility is 8μSv/h. The irradiation facility was calibrated both for thermal and epithermal neutrons flux distribution using indium foil. The neutron flux distribution in both cases exhibited some anisotropy. The average thermal neutron flux was measured to be 2.7387 * 10⁴ n/cm²/sec, while the epithermal neutron flux was 1.3395 * 10² n/cm^/sec. Using this facility, detection limits were established for Na, Al, V, Mn, As, Br, Mo, I and W

[en] A study of radiation exposure rates in the nuclear experiment of the nuclear research facilities at Obafemi Awolowo University, Ile-Ife has been made using thermoluminescent dosimeter containing CaSO₄:Dy phosphors. The data show spatial variation in the exposure rate obtained, for the thirteen sampling locations per field cycle, but with seasonal variation. From the results of this preliminary work, the average exposure rate is estimated to be 67.1 ± 1.6 n Gy h^-1

[en] Environmental pollution persists in Nigeria especially in the oil-rich regions of the Niger delta. These pollutions are due to several exploration techniques being used by the oil companies in Nigeria with little or no regard to the well-being of the society in which they operate. One of these pollution problems is due to gas flaring. We have investigated the behaviour of the surface temperature in relation to gas flaring in Obrikom area of Rivers State. Our investigations confirm a surface temperature elevation, within a 2-5 km. radius, of about 5 Celsius above the mean normal temperatures. This temperature degradation has enormous influence on the socio-economic lives and activities of the populace. Adequate remediation activities should be embarked upon in the areas to alleviate the expected environmental problems in the area. More importantly, although there are governmental legislations on gas flaring, it is a matter of necessity to enforce them to the letter in order to aim at stopping the environmental degradation before enormous and permanent damage is caused

[en] The experimental shell-model states for ²⁰Ne nuclei are well understood. The level structure consists of 0⁺, 2⁺, 4⁺, 0⁺ etc. states. Most of our theoretical understanding of the level structure of nuclei require fitting to data a two-body interaction derived from realistic forces and using these set of data as input into a standard shell-model code to calculate the energy eigenstates of the nuclei. The set of data obtained from realistic forces usually, will not give a good description of the energy eigenstates. Using a set of two-body correlation basis functions, we have generated a set of two-body matrix elements from the Reid interaction. The matrix elements have been used to calculate the level scheme for ²⁰Ne nuclei using the standard Glasgow shell-model code. most of the low lying level structure of ²⁰Ne have been reproduced and results compare reasonably with experimental data

[en] Environmental degradation due to oil activities in the oil rich Niger Delta of Nigeria is daily approaching a non-tolerance level. Pollutants come from various aspects of operation ranging from seismic operations through drilling to the refinery stage. Gas flared daily by Oil Companies constitute a major health hazard in this country. Environmental pollution due to gas flaring at Oyigbo area of Rivers State is hereby reported. Surface temperature-distance variations were investigated for both dry (March) and rainy (June) seasons. Physical and chemical properties of the rainwater from the areas were also measured and analysed. The results show a surface temperature elevation of about 4.1 Celsius above the mean normal diurnal temperature within a 3.00 km. radius. An average pH 4.25 was recorded thus showing the acidic nature of the environmental rainwater from the area. All other measured parameters showed serious deviations from standards. This temperature elevation and increased acidity of the rainwater have enormous influence on socio-economic lives and the activities of the populace especially on their source of income which is mainly small scale farming. It is therefore necessary that Government agencies empowered to monitor environment especially FEPA should implement all the existing legislation on gas flaring and be more involved in the design and location of gas flaring stacks. These stacks should be located at least 2 km. from towns and villages