African Journals Online
Journal of Applied Science and Technology
(JAST)

Abstracts (VOL. 4, Nos. 1 & 2)

Original Research Papers:

Journal of Applied Science and Technology (JAST), Vol. 4, Nos. 1 & 2, 1999, pp. 1 – 4
EFFECT OF Ag AS AN IMPURITY ON THE DIELECTRIC CONSTANT OF AMORPHOUS As₂S₃
R. K. Nkum
Department of Physics, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.

ABSTRACT
The effect of silver (Ag) as an impurity on the dielectric constant of amorphous arsenic sulphide (As₂S₃) has been investigated using a simple inductance-capacitance (L-C) circuit. The dielectric constant was found to decrease with increasing concentration of Ag in the amorphous system. The dielectric constant, _r(x), depends on the Ag concentration, x, according to the relation, _r(x) = 7.44 exp (-0.17x). The decrease in the dielectric constant is explained as being due to the fact that the addition of Ag to the glassy As₂S₃ leads to a chemical ordering which reduces the polarization of As₂S₃.

Journal of Applied Science and Technology, Vol. 4, Nos. 1 & 2, 1999, pp. 5 - 14
A GRAIN BOUNDARY SLIDING MODEL FOR CAVITATION, CRACK GROWTH AND FRACTURE IN POLYCRYSTALLINE COPPER
A. Ayensu
Industry, Natural & Social Sciences Sector, CSIR, P. O. Box M. 32, Accra, Ghana

ABSTRACT
A model is presented for cavity growth, crack propagation and fracture resulting from grain boundary sliding (GBS) during high temperature creep deformation. The theory of cavity growth by GBS was based on energy balance criteria on the assumption that the matrix is sufficiently plastic to accommodate misfit strains produced during the growth of the cavities, and that the cavities were caused to grow as a result of GBS and that sliding would not occur without concurrent cavity growth. This condition then allows shear stress acting on the boundary to do work in opening up the cavity. For elongated cavities, the model predicts a critical stress for fracture of the Griffith type. An equation was derived to establish a link between cavitation and the sliding strain, which was found to describe fairly well the two stages of cavity growth as confirmed by experimental results.

Journal of Applied Science and Technology (JAST), Vol. 4, Nos. 1 & 2, 1999, pp. 15 – 23
STEADY STATE OPERATIONAL CHARACTERISTICS OF GHANA RESEARCH REACTOR-1
E.H.K. Akaho, B.T. Maakuu, D.N.A. Dodoo-Amoo and S. Anim-Sampong
Department of Nuclear Engineering, National Nuclear Research Institute,
Ghana Atomic Energy Commission (GAEC), P.O. Box LG80, Legon-Accra, Ghana.

ABSTRACT
Steady state operational characteristics of the 30 kW tank-in-pool type reactor named Ghana Research Reactor-1 were investigated after a successful on-site zero power critical experiments. The steadystate operational character-istics determined were the thermal neutron fluxes, maximum period of operation at nominal power and calibration curve for the central control rod. Using the gold-foil activation method, thermal fluxes of 5.0 x 10¹⁰, 5.0 x 10¹¹ and 1.0 x 10¹² ncm^-2s^-1 corresponding to the power levels of 1.5, 15 and 30 kW respectively were measured and the values used to calibrate the flux monitoring meter on the control console and to adjust the amplification factor for the micro-computer control system. The calibration factor of 1.09 for the control console and the amplification factor of 1.61 for the micro-computer control system were used to obtain a perfect agreement with the measured fluxes on the two independent systems. At the nominal power, the reactor operated continuously for 6.5 hours before the control rod attained its uppermost level of 230 mm. The integral calibration curve obtained theoretically followed a similar trend with measured values and the computed control rod worth of 7.1 x 10^-3 Dk/k compared favourably with the measured value of 7.0 x 10^-3 Dk/k.

Journal of Applied Science and Technology (JAST), Vol. 4, Nos. 1 & 2, 1999, pp. 24 – 30
THE EFFECT OF LOW-DOSE GAMMA RADIATION ON THE BIOCHEMICAL STABILITY OF SOME INTRAVENOUS FLUIDS.
C.M. Gbedemah, A. Adu-Gyamfi, A. Owusu-Biney, R. Boatin, & B. Boateng +
Biotech. & Nuclear Agric. Research Institute
Ghana Atomic Energy Commission (GAEC), P. O. Box LG. 80, Legon-Accra, Ghana.
+ Intravenous Infusion Limited, P. O. Box 63, Koforidua, Ghana.

ABSTRACT
Low-dose gamma radiation has been applied to intravenous fluids to enhance the sterility assurance levels. This study was undertaken to determine the stability of gamma irradiated 2.5 % dextrose, 2.5 % dextrose in saline, Ringers lactate and Gastrointestinal replacement fluid at doses of 0, 2, 4, 6, 8, 10 and 20 kGy. Parameters such as pH, dextrose and lactate concentration, pyrogen test and concentration of ions such as Na⁺, K⁺, Ca²⁺, and Cl^- were investigated. There was considerable stability for the various parameters of the intravenous fluids after irradiation. Although there were slight variations after irradiation, the concentration of most of the mineral elements were within the normal factory range at doses below 8 kGy. The pH at doses below 8 kGy was fairly stable. The formation of pyrogen was minimal since all the fluids produced temperature rises less than the threshold value of 1.15 ⁰C.

Journal of Applied Science and Technology (JAST), Vol. 4, Nos. 1 & 2, 1999, pp. 31 – 38
REGULATORY AND RADIOLOGICAL ASSESSMENT OF Cobalt-60 TELETHERAPY UNIT AT KORLE-BU HOSPITAL
Emi-Reynolds G. & Kyere A.W.K.
National Nuclear Research Institute, Ghana Atomic Energy Commission (GAEC),
P.O. Box L80, Legon-Accra, Ghana.

ABSTRACT
The regulatory and radiological safety of a Radiotherapy Unit has been assessed based on the technical and performance specification given on the GWGP 80 cobalt-60 equipment, the biological shielding effectiveness and the organizational structure for the operation of the facility. The assessment involved the evaluation of the system of safety controls and mechanisms, system of personnel monitoring, operating and emergency procedures up to waste management provision and the definition of responsibilities of staff and their training needs. Calculations and measurements were carried out on the structural shielding design of the cobalt-60 unit by standard methods. Personnel Monitoring reports on four (4) staff members were also compared with calculated and measured results. The results obtained and measurements made, all fall below the regulatory effective dose limit of 20 mSv per year for staff and 1 mSv per year for the public.

Journal of Applied Science and Technology (JAST), Vol. 4, Nos. 1 & 2, 1999, pp. 39 – 43
DISPLAYING AN OUTLIER IN MULTIVARIATE DATA
B.K. Gordor & N.R.J. Fieller +
Department of Mathematics, University of Cape Coast, Cape Coast, Ghana
+ School of Mathematics and Statistics, University of Sheffield, U.K.

ABSTRACT
A graphical technique for highlighting the presence of an outlier in a multivariate data set is proposed. The technique involves the projection of the multidimensional data onto a single dimension called the outlier displaying component. When the observations are plotted on this component the outlier is appreciably revealed.

Journal of Applied Science and Technology (JAST), Vol. 4, Nos. 1 & 2, 1999, pp. 44–58
RETRIEVAL OF LANDUSE AND HYDROLOGY-BASED PARAMETERS FROM REMOTE SENSING SATELLITE SYNTHETIC APERTURE RADAR DATA: THE CASE OF THE VOLTA LAKE BASIN IN GHANA
S. Opoku-Duah, K. Kankam-Yeboah, G. Calabresi + & J. Lichtenegger +
Water Research Institute (CSIR), P.O. Box M.32, Accra, Ghana
+ European Space Agency (ESRIN), Via Galileo Galilei, CP 64, 00044 Frascati, Italy

ABSTRACT
Landuse and hydrology-based information on the Volta Lake Basin have been retrieved from Satellite remote sensing data. The results obtained could be applied in Hydro-Geographical Information System models, such as the TOPMODEL, for water balance studies. Eight Synthetic Aperture Radar Precision Images of the lake area acquired between August 1994 and June 1997 were processed into two sets of multi-temporal images (central and northern portions of the catchment areas, respectively). The images were analysed based on changes in land surface rough-ness, as characterised by the dynamics of the radar (satellite) backscatter coefficient. The first image (Mid-Volta Lake Sub-basin) revealed high variation in vegetation, soil and water surface roughness both in time and space. The lake also showed consistent high surface roughness (> -6.0 dB) in correspondence with seasonal passes of the South-west Monsoon and Northeast Trade Winds. The second image (Upper Volta Lake Sub-basin) demonstrated a more dynamic vegetation and soil surface roughness in relation to intense landuse activities (e.g. burning-induced shifting cultivation, livestock grazing, etc.). Whereas a quantitative relationship between cumulative seasonal rainfall and lake elevation could be established, direct effects of landuse on lake level fluctuation could not be easily deduced.

Journal of Applied Science & Technology (JAST), Vol. 4, Nos. 1 & 2, 1999, pp. 59 – 66
THE POTENTIAL OF leucaena leococaphala ALLEY CROPPING AS AN INTERVENTION FOR SOIL FERTILITY IMPROVEMENT IN GHANA.
M. Bonsu, A. M. Addae & J. A. Poku +
Department of Soil Science, School of Agriculture, University of Cape Coast, Cape Coast.
+ Crop Services Directorate, Ministry of Food and Agriculture, Accra

ABSTRACT
A three-year old leucaena leococephala alley cropping with maize was evaluated with respect to soil chemical pro-perties and grain and stover yields on a Coastal Savanna Soil of Ghana. The four treatments established between the leucaena hedgerows were: half rate of recommended fertilizer for maize (T1); full rate of recommended fertilizer for maize (T2); pruning of leucaena leococephala alone (T3); and pruning of leucaena leococephala plus half fertilizer rate (T4). The experimental design was randomized complete block design with three replicates. The pruning was applied as mulch over the soil surface. Soil chemical analysis indicated that organic carbon and total nitrogen increas-ed significantly when leucaena pruning alone was added. Addition of mineral fertilizer to pruning caused a decrease in soil organic carbon but an increase in the total available nitrogen. The amount of phosphorus added to the soil did not improve with addition of leucaena pruning. Addition of mineral fertilizer to leucaena pruning increased the yield of maize grain but the yield was not significantly different from adding leucaena pruning alone. Therefore, for the resource-poor farmer in the humid tropics, alley cropping with leucaena could be a recommended sustainable soil management practice discounting some limitations such as labour that goes with the practice during the cropping season.

Journal of Applied Science and Technology (JAST), Vol. 4, Nos. 1 & 2, 1999, pp. 67 – 71
SEWAGE, SEPTAGE AND FAECAL SLUDGE MANAGEMENT IN TAMALE MUNICIPALITY OF GHANA
I. Hodgson & S.A. Larmie
Council for Scientific & Industrial Research, Water Research Institute,
CSIR-WRI, P. O. Box M 32, Accra

ABSTRACT
The sewage, septage and faecal sludge management profile in Tamale Municipality have been studied in relation to the different handling facilities used and the technologies adopted for their treatment and disposal. The human excreta facilities available include pan latrines, public latrines, and water closet systems. The sewage treatment facilities found were the Trickling Filter and Waste Stabilization Ponds, which were found to be in deplorable states. The suspended solids of the final effluent were 140 mg/l compared to the Environmental Protection Agency guideline value of 50 mg/l. The faecal coliform in the effluent from the Trickling Filter Plant was found to be as high as 6,600,000-counts/100 ml compared to the recommended guideline value of 5000 counts per 100 ml for hot climates. The sewage treatment facilities must therefore be rehabilitated to meet acceptable standards of environ-ment and health requirement.

Topical Issues:

Journal of Applied Science and Technology (JAST), Vol. 4, Nos. 1 & 2, 1999, pp. 72 – 81
VALUATION, PAYMENTS AND REMUNERATION FOR TECHNOLOGY TRANSFER
Adapted from Manual on Technology Transfer Negotiation Investment and Technology Promotion Division of UNIDO
Copyright © United Nations Industrial Development Organization, 1995.
Communicated by A. Ayensu, INSS, CSIR, P.O. Box M32, Accra

ABSTRACT
Payment schemes in technology transfer agreements are more complex than those in simpler commodity trans-actions. In technology transfer, simple concepts such as “price” and “cost” take more varied forms as “royalties”, “franchise fees”, “technical service fees” etc., each of which carries different meaning. This review offers compre-hensive treatment of the varieties of payment in technology transfer agreements, discusses their advantages and attendant obligations, provides the rationale behind the different types of payment schemes and includes criteria for quantifying and assessing them as well as the legal administrative provisions.

Journal of Applied Science and Technology (JAST), Vol. 4, Nos. 1 & 2, 1999, pp. 82 – 87
SCHEDULE FOR PATENT APPLICATION AND REGISTRATION
Communicated by A. Sackey & A. Ayensu, CSIR, P.O. Box M32, Accra, Ghana.

ABSTRACT
The application and registration for patents in Ghana is governed by the Patent Law of 1992, i.e. PNDCL 332 gazetted in June 1993. Extracts and key provisions of the law are presented for informed opinions on matters of commercialization of research and technology transfer in relation to inventions and patent rights. Also discussed are the current levels of fees for registration at national, regional and worldwide levels, other limitations and encumbrances thereof.

Journal of Applied Science and Technology (JAST), Vol. 4, Nos. 1 & 2, 1999, pp. 88 – 89
CLEANER PRODUCTION MECHNISMS AND WASTE MINIMIZATION
Communicated by A. Ayensu, INSS, CSIR, P.O. Box M32, Accra, Ghana.

ABSTRACT
For production processes to be sustainable, there is an urgent need to adopt cleaner production mechanism and waste minimization programmes. In agricultural production, farm wastes could be converted to products such as composite materials for industrial applications. In the manufacturing sector, recycling of industrial waste could minimize over exploitation of natural resources and safeguard the integrity of the environment. The ultimate objective of adopting cleaner production mechanisms is to ensure that all systems of production become ISO 9000 and 14000 compliant.

Journal of Applied Science and Technology (JAST), Vol. 4, Nos. 1 & 2, 1999, pp. 90 - 92
WORKING SAFELY WITH COMPUTERS AND VIDEO DISPLAY TERMINALS
Communicated by C. Buabeng-Andoh
Industry and Natural Sciences Sector, CSIR, P.O. Box M. 32, Accra, Ghana

ABSTRACT
The expanding use of computers has enhanced efficiency and productivity in many work places in Ghana. Its importance in everyday lives for work, education, research, etc., is enormous. Despite these numerous advantages, computer operators express concern about the harmful effects of its operation. This article discusses the potential hazards and the interventions the computer operators must adopt to reduce these harmful effects.