282 research outputs found
Using Approximate Method for the Construction of Mosque Domes
Domes remain a unique structure in building
construction as a result of stylistic forms and composition
in the field of architecture. They are important elements
that adequately define the Islamic architecture. The
construction of domes which is a doubly curved surface
and formed by rectilinear structures always resulted in
difficulties to get the curvilinear shape correctly. The study
therefore made the use of an approximate method to
develop the dome using materials that are provided in the
locality. The knowledge of descriptive geometry in surface
development was adopted to obtain approximation cone
components that produce the hemispherical dome. The
components were properly installed and supported by
centering which composed eight equally spaced timber
frameworks that were supported by planks. Lack of
appropriate modern technological advancement should not
be factor militating against production of perfect forms,
thus appropriate technical drawing basic skills should be
acquired by the builders to take the construction of dome
from a poor to a good system of accurate centering with
good quality control
A multi-period Markov model for monthly rainfall in Lagos, Nigeria
Long periods of historical hydrological data such as rainfall and streamflow which are necessary for planning and design of water resources projects, are often not available and have to be forecasted. Many models available for this were developed and tested in developed countries in temperate climates and so their application in tropical climates is questionable. A twelve-period Markov model has been developed for the monthly rainfall data for Lagos, along the coast of South Western Nigeria. The goodness of fit of the model was assessed by estimating the autocorrelations of the residuals of the historical data (from January 1924 to December 1983) for lags one to sixty. A 95% confidence band was also established for the autocorrelations. The results show that all but two of the autocorrelations fall within the 95% confidence band confirming that the residuals are indeed white noise. This indicates that the model is very adequate.Keywords: Markov, multi-perio, rainfall mode
Water Withdrawal Trends, Cost and Uses in Ota, Ogun State, Nigeria
Water is an essential component
of life. Globally, there is a drawback
in its availability and this is
increasing and duplicating itself
thereby intensifying the struggle
for scarce water resources. This
study assessed the water resource
availability, access, water withdrawal
trends, and presents the outcome
of a survey of water use pattern
in a semi-urban settlement in
Southwest Nigeria. The study
employed the use of a detailed
questionnaire and oral interview
for the collection of data. The
water use pattern extends to
various water consumers such as
residential, institutional, commercial
and industrial. The collected data
were analyzed using descriptive
statistics. The results showed that
70% of the settlement depend
on groundwater alone, while 30%
on surface water. The findings in
the study revealed that the rate
of patronizing commercial water
seller is very high compared to the
government approved tariff rate of
66.7% price margin, and there is an
increasing demand on water from
the various settlements considered.
The outcome will enable better
investment and management
decisions in water withdrawal and
usage in the near future as this must
be based on estimates of future
needs and the available resource
potentials
Review of Sustainability in Self Compacting Concrete: the use of waste and mineral additives as supplementary cementitious material and aggregate.
Concrete is one of the commonly used construction materials, but there is a need to develop a new
and sustainable technology to make concrete more affordable. With the advancement in
technology, concrete was no longer seen as a three entity (binder, aggregate, and water). The
unique workability properties of SCC make it unique in the concrete industry. This review assessed
the materials, strength, rheological properties of agricultural waste, industrial waste and mineral
additives in SCC production. The effect of the utilization of these additives and replacements on
structural, mechanical and rheological properties of SCC was espoused. The review revealed that
the use of both industrial and agricultural waste enhances the strength properties of SCC.
Additionally, the use of agricultural waste improves the rheological properties of fresh concrete.
The utilization of expansive material should be discouraged in SCC production. The review
revealed that SCC developments ensure a good balance between deformability and stability. It was
therefore recommended that SCC should be utilized in pavement construction, particularly when
high axle load is expected
Modelling the Effect of Income and Car Ownership on Recreational Trip in Akure ,Nigeria
The effect of income and car ownership on
recreational trip pattern in the study area was analysed,
focusing on the frequency of trips, modal choice and the land
use pattern. It is an attempts to extend research on travel
characteristics and behaviour to cities of the developing world with focus on Akure metropoli
Kinetics of the reduction of μ–oxo–tetrakis(1, 10–phenanthroline) diiron (iii) complex by thiourea in aqueous phenanthrolinium buffer
The homovalent oxo-bridged binuclear iron(III) complex ion [Fe2O(phen)4Cl2]4+ (phen = 1, 10–phenanthroline) aquates to [Fe2O(phen)4(H2O)2]4+ in aqueous phenanthrolinium buffer solution (pH 3.25–4.50). The reaction of [Fe2O2(phen)4(H2O)2]4+ with thiourea in this buffer solution to give [Fe(phen)3]2+, sulphite ion and urea was studied spectrophotometrically at 510 nm and found to be first order in [Fe2O2(phen)4(H2O)2]4+ and of mixed zero and first order in thiourea, i.e. reaction order with respect to thiourea varies from one to zero on increasing the thiourea concentration from 1.0–7.0 × 10-2 mol dm-3. The reaction is characterized by adduct formation. Changes in pH from 3.25 to 4.50 and ionic strength from 0.10 moldm-3 to 0.60 moldm-3 of the reaction solution were found to have no effect on the reaction rate. Catalysis and retardation were observed with the addition of Mg2+ and CH3COO- ions respectively. A plausible mechanism consistent with the results obtained is proposed.Keywords: kinetics, mechanism, oxo-bridged, phenanthrolinium buffer, thioure
ASSESSMENT OF THE GEOTECHNICAL PROPERTIES OF TERMITE REWORKED SOILS
The determination of the geotechnical properties of inhabited termitaria (termite mounds) from three different
locations in Lagos, Nigeria was carried out. Soil samples were taken at the cores of termitaria and also at 3m of either side
of termitaria. Nine bulk representative soil samples depicting three termitaria soils and six adjacent soil samples were
collected. Some geotechnical properties such as specific gravity, grain size distribution, consistency limits, linear
shrinkage, CBR, and consolidation of the soils were determined. The chemical properties of the termitaria soil as compared
to the adjacent surrounding soil was also analysed. The result showed that the geotechnical properties of termitaria are far
better than the adjacent or surrounding soils. The activity of termites was identified as the primary cause of these
improvements
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