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- ItemOpen AccessDevelopment of a Synchonous Data Transmission System.(Obafemi Awolowo University, 1986) Agomo, Uchenna UdochukwuThe development of a 2 - channel synchronous data transmission system is presented. The system is capable of accepting at the input two separate analog voltage signals that have zeroto 1kHz frequency range and amplitude not greater than 2.5 volts. The two analog voltage signals are multiplexed at the input of the-system and converted to corresponding digital representations. These digital representations are then transmitted by means of digital gates from the transmitting section serially and with transmission clock frequency of 6.6 MHz, through cable wire to a remote receiving section, where the received digital representations are re-converted to analog voltage signals and demultiplexed to produce at the output, two separate analog voltage signals plus noise. The noise level does not exceed 5% of the signal level when filtered and leaves analog voltage signals with the same characteristics as those at the input of the system. The designed system is simple and can be used for laboratory demonstration on synchronous data transmission system. It may be useful as a communication medium for data exchange between two data processing terminals. The system may be used to transmit voltage signals from a central storage facility to a remote destination. In such circumstance the signals may be those derived from research results, medical findings and student/staff records. A computer base may then be set up and made accessible to users.
- ItemOpen AccessEffect of Drug Pre-Treatment on The Metabolism of Methyrapone .(Obafemi Awolowo University, 1985) Okereke, Samuel EmekaMetyrapone (SU 488), an inhibitor of 11β - hydroxylase used an a diagnostic and therapeutic agent in the treatment of Cushing's disease, has been found to be metabolised in vivo in rats mainly to metyrapol via reductive mechanism and to the N.-oxides in oxidative mechanism. A significant sex difference as to the production of metyrapol was observed; being higher in the male rats (94 ± 1%) than in the female (64 ± 2%). The influence of drug pretreatment on the metabolism of metyrapone was inventigated in the rats. It was observed that phenobarbital, ethanol and pregnenolone significantly (P< 0.05) caused an induction of the metyrapone N-oxide (B) in the male rats while anthracene did not cause any significant induction. Only ethanol significantly (P<0.05) induced the production of N-oxide A. On the other hand cimetidine a cytochrome P- 450 inhibitor and methimazole, an FAD (flavine Adenine dinucleotide) mediated inhibitor of cytochrome P-450, inhibited the formation of Noxide (13) and slight increase in metyropol formation ccmpared to that produced in the inducers. In the female rats, only phenobarbital significantly (P < 0.05) induced the production of both Noxides with a significant decrease in amount of metyrapol formed. While anthracene has no effect on the formation of both N-oxides of metyrapone, (though with increase in amount of metyrapol formed), ethanol, cimetidine and methimazole inhibited the production of metyrapone N-oxide (B) and (A) with a preferential increase in the amount of metyrapol formed. These then suggest a possibility of both FAD and cytochrome P-450 influence in the oxidative metabolism of metyrapon
- ItemOpen AccessAn valuation of The use of Mechanical Plant in Construction: a Case Study of Selected Number of Sites.(Obafemi Awolowo University, 1985) Lasabi, Babatunde TajudeenThe study focuses on the practice of managing construction plants as a pre-condition for their affective utilisation in the Nigerian construction industry. It shows that the economic life of a plant depends on adequate maintenance and that appropriate education and training for the plant operators enhances the efficiency of plants and equipments. It also discusses the issue of costing in relation to construction operations and hence highlights the consequences of inadequate computation of costing items. The research methodology includes the examination of plant use management taking cognisance of the contractors' organisational set up as a basis for operation. The research concludes with a set of recommendations such as adequate training of operators, restricted choice of brand of plants and adequate managerial personnel in order to enhance the productivity of contractors.
- ItemOpen AccessA Study of Recruitment, Training and Retention of Adult Education Personnel in Oyo State.(Obafemi Awolowo University, 1985) Olagunju, Pius SoladoyeThis study examined the recruitment, training and retention of Adult Education personnel in Oyo State. Data were collected from available records in the Ministries of Education, Local Government and the Social Welfare, Youth Sports and Culture. In addition, interview guides and questionnaires were used. Using percentages and tests of correlations where appropriate, the results indicated that the recruitment of personnel for adult education was not based on knowledge, competence and interest in adult education. In addition, there was not enough motivation for adult education instructors to retain them on the job as might be required. Based on these findings, it was recommended that the Government of Oyo State should reappraise her attitude towards recruitment of staff into various adult education programmes with a view to making it possible to put adult education in competent and interested hands. The study also recommended that the rate of remuneration given to instructors should be increased in order to encourage them to be efficient and effective in the performance of their duties. Finally, the study highlighted possible areas of future research attempts. Such attempts should include a comparative study of recruitment, training and retention of Adult Education personnel in Oyo State with any other State within the Federal Republic of Nigeria
- ItemOpen AccessArchachatina (Calachatina) Marginata Haemolymph Proteins, Physicochemical Characterization of Protein B.(Obafemi Awolowo University,, 1985) Binutu, Olaoluwa OlujareThe haemolymph of Archachatina (Calachatina) marginata has been found to contain other proteins apart from the predominant protein, haemocyanin. One of the other protein components, Protein B, was isolated and purified using preparatory ultracentrifugation and gel filtration techniques. Physicochemical characterization, employing different techniques has showe that Protein B is different from the haemocyanin (and/or its subunit(s)) from this mollusc. Protein B has a molecular weight of 360KD consisting of two chains which are of identical molecular size. Amino acid composition for Protein B shows that: (i)there exist more acidic residues combined than those of the basic residues combined. (ii) there is a very large occurence of Proline residues (iii) there is also a large amount of cysteine residues. There is one gram atom of copper per dimer. Protein B is a glycoprotein. The carbohydrate portion is made up of units of acetylglucosamine and galactosamine. Peptic peptide fractionation of reduced carboxymethylated Protein B has shown that most of the carbohydrate can be found on a peptide having a mass of 15KD.