African
Journals Online
Global Journal of Pure and Applied Sciences
VOLUME 9, N0 3
ABSTRACTS
Bacterial enzyme
biosyntheses inhibition: a tool for ecotoxicity assay
L. O. Odokuma and G.S.C. Okpkwasili
Department of Microbiology, Faculty of science, University of Port
Harcourt
Abstract
The inhibition of
biosyntheses of four bacterial enzyme systems by 39 chemicals (hydrocarbon
fuels, oil spill dispersants, household detergents, drilling chemicals and
crude oils) were examined as a tool for ecotoxicity assay. The enzyme systems
were two extracellular inducible enzymes tryptophanase and a - glucosidase
produced by Escherichia coli and Bacillus licheniformis respectively, one
intracellular inducible enzyme b - galactosidase in E. coli and the constitutive enzymes in
Nitrobacter mediating the oxidation of nitrite to nitrate “nitritase”.
Ecotoxicity assay results were obtained within 5 hours after commencement of
tests. Beta –galactosidase biosynthesis was the most insensitive to the 39
chemicals. Tryptophanase and a-glucosidase biosyntheses
displayed similar but higher levels of sensitivities to the chemicals. “Nitritase”
enzymes biosynthesis was the most sensitive to all the toxicants. The
inhibition of constitutive enzyme systems such as the “nitritase” enzyme system
may thus be considered as a tool for rapid ecotoxicity assays.
Keywords:
Constitutive, Inducible, Ecotoxicity, Extracellular Intracellular.
Effect of
processing and storage methods on the shelf life and incidence of insect pests
on smoked fish
* M.O. Ashamo and O.E. Ajayi
Department
of Biology Federal University of Technology, P.M.B. 704, Akure, Nigeria
Abstract
The effect of processing and storage methods on the shelf life and
incidence of insect pests on stored smoked fish was carried out on two types of
fishes, Tilapia sp and Clarias sp. Two samples were used; one
sample of already smoked Clarias obtained from Oba’s market, Akure. The
other sample (Tilapia and Clarias) obtained fresh and
hygienically smoked instantly in the laboratory. These samples were packed in
different packaging materials; polythene, aluminium foil, plastic container,
and carton and stored at low (refrigeration) and ambient temperatures. For the
period of 90 days of storage, the sample that was processed in the laboratory
did not show any pest infestation, while the already smoked fish obtained from
the market showed infestation with Dermestes after ten days of storage
for all the packaging materials. Low temperature storage proved to be the best
storage techniques for all the packaging materials. The samples stored in
carton at the ambient temperature were better than those of other materials.
Keywords: processing,
packaging materials, infestation, storage methods.
Syntheses
and spectral properties of iron(II) complexes with tetraaza(12) macrocyclic
ligands
N. T. Akinchan1 and
P.M. Drozdzewski2
1Department of Pure and
applied chemistry, University of Calabar, Calabar, Nigeria
2Institute of
Inorganic Chemistry, Wroclaw University of Technology, Wroclaw, Poland.
Abstract
The iron(II) complexes of
1,4,7,10-tetraazacyclododeca-1,3-diene (L1) and
2,3-dimethyl-1,4,7,10-tetraazacyclododeca-1,3-diene (L2) have been
prepared and studied by means of vibrational and electron spin resonance (esr)
spectroscopy. Based on elemental analysis and spectroscopic properties, the
structure for the complexes are proposed as follows: square pyramidal for [Fe(L1-2H)
H2O] and
[Fe(L2-2H)
H2O] and distorted octahedral for [Fe(L1-H)
Py (OAC)].
Keywords: Tetraazamacrocycle,
Iron(II) complex, Vibrational, esr, spectra.
Trace metal
levels in soils and vegetation from some tin mining areas in Nigeria
S.E. Kakulu
Department of Chemistry, University of
Abuja, Abuja
Abstract
Samples of soil and vegetation from some tin
mining areas of Nigeria were analysed for lead, zinc, copper and cadmium
content. The levels of Pb and Zn were found to be high in some samples. The
mean levels of metal in the vegetation were: 86.6+ 36.0, 49.6+
28.3, 12.6+4.8 and 1.4+0.8 µgg-1 dry weight for Pb,
Zn, Cu and Cd respectively whilst those in the soil were 736+120, 690+
216, 43+ 18 and 18+12 µgg-1 dry weight for Pb, Zn, Cu
and Cd respectively. The variability of metal levels in the area indicates that
in addition to mining, other anthropogenic sources of metal contribute
significantly to metal levels in the area. The EDTA – extractable metal
fractions suggest that trace metals are being mobilised in the soil and made
available to crops. The metal levels in the vegetation samples were higher than
those recorded for areas of low atmospheric metal pollution in Nigeria with no
identifiable sources. Although, there have been no cases of recorded metal
toxicity in the area, there is the need to regulate and control mining wastes
in order to prevent the effects of metal pollution in the area.
Key
words: metals, environmental samples, mining
areas.
Treatment of some
Textile Industrial Effluents using Dry Corn Stalk
V.O. Ajibola, and T.O.
Ijabor,
Department of Chemistry,
Ahmadu Bello University, Zaria.
Abstract
Corn stalk ground to various mesh sizes was
used to treat textile effluents obtained from three different industries. These
effluents were first pretreated with alum and then charcoal; passing the water
through a column, (20cm long and 5cm diameter) containing the ground corn stalk
of size diameters of 300mm, 355mm 425mm followed this treatment.
Results show that better quality effluent was obtained after treatment with the
ground corn stalk. The corn stalk ground to a size of 425mm gave the best effluent
quality.
Keywords: Textile effluent, Treatment, Corn stalk.
Effect of salts on the
functional properties of protein concentrate of water melon (Citrullus
vulgaris) seed
M.
O. Oladimeji and O. O. Obaseki
Department of Chemistry, Federal
University of Technology, P. M. B. 704, Akure
Abstract
The effects of the following
salts, KCI, NaCI, Na2SO4 and CH3COONa on the
functional properties of water melon (Citrullus vulgaris) seed protein
concentrate were studied. Results showed that the least gelation concentrate of
24% observed in the absence of the salts was improved and found between 12 and
22% in the presence of different salts concentrations. The foaming capacity of
18.7% in distilled water increased progressively from 21.1±0.1 to 61.0±0.2%
depending on the concentrations and types of salts used. In the presence of
salts the water absorption capacity decreased to between 118.2±0.2 and
141.4+0.1 compared to 152.0% in the absence of salts while emulsion capacity
also decreased to between 66.4 ±0.1 and 78.4±0.6 with salt concentration of
10.0% from 85.3±0.3. The foaming stability of 13.0% in the absence of the salts
decreased in the range of 3.1±0.1 to 11.4+0.3% by KCI and Na2SO4
but increased by NaCI and CH3COONa in the range of 15.2±0.4 to 24.
4±0.1%. The solubility was enhanced in salt solution at pH 5, suggesting that
the protein may be useful in acid food formulations.
Keywords: Salt, Functional
properties, Protein, Melon seed.
Syntheses and
spectroscopic properties of mercury(II) and nickel(II) complexes of BIS(N-Phenyl
thiourea)
N. T. Akinchan1 and P. M.
Drozdzewski 2
1. Department of Pure and
Applied Chemistry, University of Calabar, Calabar, Nigeria
2
Institute of Inorganic Chemistry and
Metallurgy of Rare Elements, Wroclaw University of Technology, WYB.
Wyspianskiego, Wroclaw, Poland.
Abstract
Mercury(II) complex, [Hg2(BPTU-2H)Cl2] and nickel(II)
complex, [Ni(BPTU-H)2] were prepared by reacting Bis(N-phenylthiourea),
BPTU, with mercury(II) chloride and nickel(II) acetate respectively. The
complexes were characterized by IR, diffuse reflectance, 1H NMR spectra and
elemental analysis. BPTU acts as monoanionic bidentate chelating agent in
nickel(II) complex, coordinating through thiolato sulphur and hydrazinic
nitrogen atoms. Its coordination nature differs in mercury(II) complex, where
it acts as dianionic bis(bidentiate) chelating agent, coordinating through
thiolato sulphur and hydrazinic nitrogen atoms to two mercury(II) ions
simultaneously. on the basis of
analysis and spectral properties, Ni(BPTU-H)2 has been
tentatively assigned square planar geometry. The [Hg2(BPTU-2H)Cl2] appears to have
binuclear structure having triangular coordination centres around mercury(II)
cations.
KeyWords: Bis(N-phenylthiourea),
mercury(II) complex, nickel(II) complex, IR,1H NMR, electronic
spectra.
Colorimetric
determination of Chloramphenicol and metronidazole in pharmaceutical
formulations after schiff-base formation with vanillin and anisaldehyde
B.
H. Ahmed and J. O. Onah*
Department of Pharmaceutical Chemistry,
Faculty of Pharmaceutical Sciences, University of Jos, PMB 2084 Jos, Nigeria.
Abstract
The nitro groups in chloramphenicol and metronidazole drugs were
reduced to their amino functions using zinc dust in concentrated hydrochloric
acid. Vanillin and anisaldehyde were used to form Schiff-base adducts with
chloramphenicol and metronidazole respectively. The chloramphenicol couple gave
an absorption maximum (lm) at 385 nm while
that of metronidazole absorbed (lm) at 400 nm. Both
colours were stable over a period of 9h. Both derivatives obey Beer/Lambert law
within the range of 1 mg/ml and 10 mg/ml that was investigated. The molar absorptivities
were 2491 and 3151 l mol-1 cm-1 for chloramphenicol and
metronidazole adducts respectively. Sandell’s sensitivity values were 8.5 ng/ml
for chloramphenicol and 22.5 ng/ml for metronidazole suggesting that the
vanillin couple was more sensitive than the anisaldehyde adduct. The adduct
formation was highly selective so quantitative recoveries indicated high
precision although statistical comparison employing Student’s t-test did not
suggest any significant (p > 0.05) difference
between the proposed and the Pharmacopoeia method. This proposed method is more
sensitive, accurate and simple to carry out.
Keywords: Chloramphenicol
and Metronidazole assay; Schiff-base adduct
Activities
of aspartate (E.C. 2.6.1.1) and alanine (E.C.. 2.6.1.2) transaminases, and
alkaline phosphatase (E.C. 3.1.3.1) in human erythrocytes of different
genotypes
D. Onwubiko 1, A.
A. Uwakwe 2 and M. O. Monanu 2*
1 Department of
Pathology, School of Clinical Medicine, Abia State University, Aba, Abia State
2 *Department of
Biochemistry, University of Port Harcourt, PMB 5323, Port Harcourt, Rivers
State
Abstract
The activities of aspartate
(E.C. 2.6.1.1) and alanine (E.C. 2.6.1.2) transaminases (AST and ALT,
respectively), and alkaline phosphatase (ALP) (E.C. 3.1.3.1) were determined in
erythrocytes obtained from 20 HbAA, 15 HbAS and 12 HbSS human subjects. The
results showed that the three enzymes had different levels of activity in these
genotypes. The mean ( + SD) activity levels of the enzymes, expressed in
U/g Hb, obtained for HbAA, HbAS and HbSS samples were: 6.75 + 0.99, 7.48
+ 1.19 and 13.37 + 1.78 for AST; 4.26 + 0.24, 4.33 +
0.44 and 7.24 + 1.49 for ALT; and, 69.24 + 8.94, 64.26 +
9.17 and 48.49 + 4.35 for ALP. However, the activity levels of the
different enzymes in HbAA were not significantly different (p>0.05) from
that observed in HbAS erythrocytes. The activity levels of AST and ALT in HbSS
erythrocytes were significantly higher (p<0.05) than that for HbAA
erythrocytes. ALP showed significantly lower activity level (p<0.05) in HbSS
than HbAS erythrocytes. There was no significant effect (p>0.05) of sex on
the activity levels of the enzymes. These findings have far-reaching
implications for the biochemical roles of these enzymes in the metabolism of
the erythrocytes from the different genotypes studied.
Key
words: transaminases, phosphatase,
erythrocyte, genotypes, pyridoxal
The velocity-thickness characteristics of the mangrove swamp low
velocity layer (LVL), South Central Niger Delta, Nigeria
C.
L. Eze*, E. E. Okwueze** and E. D Uko***
*Institute
of Geosciences and Space Technology, Rivers State University of Science and
Technology, Port Harcourt, Nigeria.
**Department
of Physics, University of Calabar, Calabar, Nigeria.
***Department
of Physics, Rivers State University of Science and Technology, Port Harcourt,
Nigeria.
Abstract
A
total of 14 upholes were shot in the Mangrove Swamp of the Niger Delta of
Nigeria. The aim of the survey was to determine the thickness and velocity of
the low velocity layer (LVL). The velocities and thickness of the layers were
computed from the reciprocals of the slopes of the straight-line segments using
the FACE Static computer program. Results obtained showed a variation in the
thickness of the weathering layer from 2.0m to 5.7m with an average of 3.40m.
The variation was random and did not show any trend. The velocity of the low
velocity layer ranges between 295ms-1 and 727ms-1 with an
average of 562.7 ms-1 while the velocity of the sub-weathering layer
ranges between 1502 ms-1 and 1918 ms-1 with an average of
1716 ms-1. These data are important in seismic static corrections
and in geotechnical engineering.
Key
words: Thickness, Velocity, Low velocity layer,
Uphole
Modeling Air-Quality in Complex Terrain Using
Mesoscale and Dispersion models – Part I: Evaluation of a mesoscale model
M. Mohr*, L.
Enger* and B. J. Abiodun**
*Department of Earth
Sciences, Uppsala University, Villavägen 16, 752 36 Uppsala, Sweden
**Department of Meteorology,
Federal University of Technology, P.M.B. 704, Akure, Nigeria
Abstract
Air-quality in a complex terrain
(Colorado-River-Valley/Grand-Canyon Area, Southwest U.S.) is modeled using a
higher-order closure mesoscale model and a higher-order closure dispersion
model. Non-reactive tracers have been released in the Colorado-River valley,
during winter and summer 1992, to study the dispersion of pollutants from a
coal-fired power plant. The main objectives of the extensive field program
MOHAVE ("Measurements Of Haze And Visibility Experiment") were to
investigate and identify the possible short- and long-term impacts of
atmospheric pollutants from major urban areas and industrial sources on the
Grand Canyon and its vicinity. In part I, the mesoscale model (MIUU model) is
described. The model results are compared with data from the meteorological
network of surface and upper-air stations within MOHAVE. The model results are
also compared with those from another mesoscale model (MM5). In part II, the
dispersion model is described. It is an Eulerian diffusion model. The model
simulations of air-quality in the MOHAVE complex terrain during the program are
compared with the available data.
Keywords: Mesoscale modeling, Dispersion, Air-quality in complex terrain
Electrical treeing in
ceramic-based insulating materials (Ba TiO3 – SiO2).
T. M. Abbey, and I. O.
Owate,
Department of Physics,
University of Port Harcourt, Choba Rivers State
Abstract
The process leading to the development of electrical trees in
ceramic-based materials (BaTi03- Si02 system) under the
influence of relatively low a.c. signals and induced vibration frequencies was
studied. The breakdown strengths of the chosen material (Ba Ti03
system) was conducted under oil whereas the dielectric properties were
determined by impendence method. It was observed that the tree-like structures
were of two types and that the initiation could have been due to partial
discharges that arose from microcracks, pores and other similar defects. This
equally shows that the mechanism of the initiation of an a.c. tree and that of
a d.c. trees are similar. Thus, if a.c. voltage is considered as a repetition
of charging and discharging processes, then one can understand that some
likeness could exist between the phenomena.
Keywords: Electrical
treeing, ceramics, insulators, breakdown, micro cracks.
Analysis of sky
condition using solar radiation data over a tropical station
Olaleye J. O+,
Ogunjobi K.O*., Okogbue E. C.+, Adedokun J.A.**
+Department of
Meteorology, FUT Akure, Ondo State Nigeria
*Department of Environmental
Science & Engineering Advanced Environmental Monitoring Research Center
Kwangu Institute of Science
and Technology, Kwangu
**Department of Physics,
Obafemi Awolowo University, lle-lfe, Nigeria
Abstract
Radiation data in Nigeria
are very sparse because radiation is not routinely measured. The data used for
this work are from the physics Department of Obafemi Awolowo University,
lle-lfe which is one of the few stations that collect radiation data in
Nigeria. The daily, global and diffuse radiation measurements have been used to
characterize the atmosphere of lle-lfe (70 14` N, 40 35` E) during
January to December 1994. The clearness index ky (=H/H0)
which gives the percentage depletion by the sky of the incoming global
radiation and the relative sunshine (s/s0) gives the measure of
cloud in the atmosphere has been adopted for use in this study. Also
investigated are the diffuse radiation Kdiff (=Hdiff/H)
and the diffuse coefficient Kcoef (= Hdiff/H0)
that mirror the effectiveness of the sky in the scattering of the incoming
radiation. Results show an average Kt value of 0.57 for year 1994
with maximum clearness index occurring in June (Kt= 0.68) and
minimum in Dec (Kt =0.42). This present study also shows that the
relative sunshine s/s0 has its minimum in August which indicates
reduced hours of sunshine and solar insolation during the monsoon month of
August in the tropical Nigeria station.
Keywords: Daily, global
and diffuse radiation, clearness index, diffuse coefficient, relative sunshine
Dose assessment
due to terrestrial gamma radiation in Ibadan, South Western Nigeria
A.M. Arogunjo* and I.P.
Farai**
*Department of Physics, Federal University of
Technology, Akure, Ondo State
**Department of Physics,
University of Ibadan, Ibadan, Nigeria
Abstract
The activities of primordial
radionuclides in surface soil at Ibadan, South-Western Nigeria have been
measured with a 7.6cm x 7.6cm NaI(TL) detector. The mean absorbed dose rate,
annual effective dose and the collective effective dose at Ibadan were
evaluated from measurement of 40K; 238U; 232Th
activities and their mean values found to be 0.070 ± 0.008 mGy.h-1, 86.1
mSv.y-1 and 344.2
man Sv.y-1, respectively.
Keywords: soil; dose; effective; collective; 40K;
238U; 232Th; exposure
Modeling air-quality in complex terrain using
mesoscale and dispersion models – part II: Evaluation of a dispersion model
B.
J. Abiodun*, M. Mohr** and L. Enger**
*Department of Meteorology,
Federal University of Technology, P.M.B. 704, Akure, Nigeria
**Department of Earth
Sciences, Uppsala University, Villavägen 16, 752 36 Uppsala, Sweden
Abstract
Air-quality in a complex terrain
(Colorado-River-Valley/Grand-Canyon Area, Southwest U.S.) is modeled using a
higher-order closure mesoscale model and a higher-order closure dispersion
model. Non-reactive tracers have been released in the Colorado-River valley,
during winter and summer 1992, to study the dispersion of pollutants from a
coal-fired power plant. The main objectives of the extensive field program
MOHAVE ("Measurements Of Haze And Visibility Experiment") were to
investigate and identify the possible short- and long-term impacts of
atmospheric pollutants from major urban areas and industrial sources on the
Grand Canyon and its vicinity. In part I, the mesoscale model (MIUU model) is described.
The model results are compared with data from the meteorological network of
surface and upper-air stations within MOHAVE. The model results are also
compared with those from another mesoscale model (MM5). In part II, the
dispersion model is described. It is an Eulerian diffusion model. The model
simulations of air-quality in the MOHAVE complex terrain during the program are
compared with the available data.
Keywords: Mesoscale modeling, Dispersion, Air-quality in complex terrain
Temperature
dependence of transport coefficients of ‘simple liquid’ below 1 K
O.S. Oyekola
Department
of Physics, University of Ibadan, Ibadan, Nigeria
Abstract
Temperature variation of transport coefficients of liquid argon below
temperature of 1 K (in reduced unit) for system of 500 atoms interacting
through a Lennard-Jones 6-12 potential using classical molecular-dynamics (MD)
simulations has been investigated. The study carried out at two densities, r* =
0.60 and r* = 0.95. Result shows erratic variations of the shear viscosity in the
two lattices structures.
KeyWords: Temperature effect, face centred, simple cubic, transport properties,
simple liquid.
Ratio estimation in poststratified sampling over two
occasions
A.
C. Onyeka,
Department of Mathematics and Computer Science, Federal University of
Technology, Owerri, Nigeria
Abstract
Two estimators are proposed
for the estimation of the second occasion population ratio, R2, of
two characters of study in poststratified sampling over two occasions. The
estimators are proposed along the line of Tripathi and Sinha (1976) and Okafor
(1985). One of the estimators, d1, is a ratio-cum-product type
estimator, while the other, d2, is a product-cum-ratio type
estimator. Both estimators do not assume knowledge of the first occasion
population ratio, R1. Expressions for the optimum matching or
replacement fractions of both estimators are obtained since the estimators are
based on a partial replacement of sample units on the second occasion.
Conditions under-which one estimator is to be preferred to the other estimator
are obtained for repeated samples of fixed sizes.
Keywords: Successive sampling,
poststratified sampling, ratio estimation, matching or replacement fraction,
repeated samples.
Axial velocity
distribution of a two-component plasma in a magnetised tube of slowly varying
section
K. D. Alagoa* and T. M.
Abbey**
*Department of Physics,
University of Science & Technology, P.M.B. 5080, Port Harcourt, Nigeria
**Department of Physics,
University of Port Harcourt, Nigeria
Abstract
In this study we investigate the combined effects of channel
indentation and presence of neutral gas (impurities) on the flow of a
two-component plasma gas through a magnetized cylinder with indentation. For
small indentation, expressed in e, analytic
solutions are obtained for the axial velocities, induced magnetic fields,
current densities and pressure gradients. The effects of the channel
indentation and percentage impurities on the flow characteristics are shown
graphically and discussed quantitatively.
|