Engineering initiatives for water hyacinth control with emphasis on the design, control and installation of the water hyacinth boom (barrier) across River Niger, north of Kainji Lake

(13 page document

Performance Evaluation of a Hybrid Fractional Carrier Frequency Offset Estimator in OFDM

The major drawback of the orthogonal frequency division multiplexing (OFDM) system is high sensitivity to synchronization errors caused by carrier frequency offsets (CFOs), which result in degradation in the bit error rate (BER) performance. This paper investigates the performance of a hybrid fractional carrier frequency offset estimator (FCFOE) for frequency synchronization in the OFDM system. The hybrid FCFOE exploits the pilots inserted within the OFDM symbol for channel estimation together with the information inherent in the cyclic prefix (CP), with a view to improving the estimation of the CP-based FCFOE. The performance of the developed hybrid FCFOE was evaluated in terms of the mean squared error (MSE) and bit error rate (BER) using OFDM-QPSK and OFDM-16QAM schemes it turn. The simulation results show that the hybrid FCFOE only gives slightly better performance over the CP-based FCFOE; but the performance enhancement of the hybrid FCFOE is noticeable in OFDM-16QAM. Keywords: Carrier frequency offset estimation, Hybrid, Orthogonal frequency division multiplexing, Synchronization, Maximum likelihood, Cross-correlation

Determinants of Wheat Production in Nigeria (1981 – 2019): A Bounds Testing Approach

The study examined the analysis of trends and determinants of wheat production in Nigeria between 1981 and 2019. The data for this study are time series data at macro level spanning from 1981 to 2019. All the data were largely sourced from Food and Agriculture Organization (FAO) statistical data base, Penn world data of the university of Pennsylvania and Central Bank of Nigeria (CBN) statistical bulletin. The data include output of wheat in Nigeria, local and international price of wheat, real exchange rate, and external reserve. The data were analyzed using autoregressive distributed lags to access the relationship between wheat output and factors affecting wheat production in Nigeria. Results showed that external reserve, per capita income, market reforms and technological advancement significantly increased wheat production in Nigeria. Consistency of government policies and policy actions geared towards reducing wheat imports should especially pursued by the government

An Empirical Analysis of Climate Change Effects on Selected Cereals Acreage in Nigeria: A Ricardian Approach

This study examined the relationship between the acreage of selected cereal crops and climate variables for the period 1995 – 2021 in Nigeria. The study was based on maize, rice, millet and guinea corn for all the states in Nigeria for the period of study. Data for acreage of selected cereal crops for all the time period were collected from the Nigeria Bureau of Statistics (N.B.S) while data on the two important climate variables required for crop growth – temperature and precipitation – used for the analysis were obtained from the Nigerian Metrological Agency. The results indicated positive response of the acreage of the cereal crops to increase in temperature which is possibly due to other factors that serve in cushioning the effect of the temperature such as irrigation; rainfall has mixed relationship with the acreage of the cereal crops except; the negative coefficient of trend variable shows a negative relationship with the acreage of selected cereal crops. The results of the elasticity of cereals acreage to climate variables show that the acreage of rice is inelastic to rainfall but elastic to temperature. However, maize, millet and guinea corn acreage are all appreciably elastic to precipitation and temperature changes. These results also reveal that with the passage of years and climate factors running contrary to agricultural productivities, cereal crops farmers in Nigeria were adopting new measures to cope with the negative effect of climate change. Climate adaptation measures which include the use of drought or heat resistant varieties, early sowing, mixed cropping, tillage system alteration and the utilization of land that has been considered too marginal for agricultural cultivation reduces the negative effects of climate change on cereal crops acreage and enhances the positive factors

Regional Analysis of Acceptance of COVID-19 Vaccines in Nigeria

Background: Attempts at curbing the spread of SARSCoV-2 have resulted in formulation and adoption of COVID-19 protocols in different countries. To further prevent contracting the virus, many developed countries are administering COVID-19 vaccines to their citizens and residents while the developing countries are not left out. The Nigerian government began administering COVID-19 vaccines on March 9, 2021. This study therefore analysed the acceptance of COVID-19 vaccines across different states in Nigeria. Methods: The study utilised secondary data of COVID-19 vaccination in Nigeria. The dataset was obtained from OpenAFRICA, which was first created on September 1, 2021 and last updated in September 29, 2021. The data were statistically analysed and then mapped using the Geographic Information System. Results: The findings showed a very low level of acceptance of the full doses of COVID-19 vaccines vis-a-vis the population of each of the thirty-six (36) Nigerian States. Conclusion: We therefore conclude that the population responses to receiving COVID-19 vaccines is very low in Nigeria, which signals a high level of health risk and vulnerability to the virus

Population dynamics of indoor sampled mosquitoes and their implication in disease transmission in Abeokuta, south-western Nigeria

Background & objectives: A longitudinal study was carried out to investigate the speciescomposition, seasonal abundance, parity and feeding preference of indoor sampled mosquitoes inAbeokuta, south-western Nigeria.Methods: The mosquitoes were sampled weekly from five stratified locations using Center forDisease Control (CDC) light-traps between August 2005 and July 2006. The mosquitoes wereexamined for abdominal condition and dissected for age composition. Microscopic and precipitintechniques were also employed for the determination of host blood source.Results: A total of 2969 mosquitoes which belong to 10 species of mosquitoes were collectedduring the study period. Mansonia africana (35.65%) constituted the most abundant species followedby Culex quinquefasciatus (32.23%) and Anopheles gambiae complex (13.52%). Other species indecreasing order of abundance were Coquilletidia maculipennis (8.2%), Aedes albopictus (5.9%),Ae. aegypti (1.93%), M. uniformis (1.81%), Cx. duttoni (0.25%), Cx. tigripes (0.25%) and An.funestus (0.25%). Seasonal abundance revealed a significant difference (p <0.05) in the populationof mosquito vectors collected during the wet season as compared to the dry season and theirabundance was positively correlated with rainfall. The results showed that the majority of thevector species collected were unfed and nulliparous. Moreover, the blood meal test was positive forhuman blood.Conclusion: The preponderance of mosquitoes observed in the study is of public health concernsince they serve as vectors of most tropical diseases including malari

Traumatic Brain Injury and Metabolic Dysfunction Among Head Injured Patients in a Tertiary Hospital in North-Central Nigeria

Traumatic Brain Injury (TBI) is a common health problem which is one of the main causes of chronic disability and it is associated with hormonal and metabolic disorders. This work was carried out to investigate the relationship between some stress hormones (i.e. prolactin and cortisol) and plasma glucose level in TBI patients. Twenty-five TBI patients were included in the study consecutively. All patients underwent basal hormonal and plasma glucose evaluation within 24 hours of admission. One of the patients died during the acute phase. The results of the study show that prolactin and glucose levels were positively correlated with the Glasgow Coma Scale (GSC). Cortisol levels were observed to be highest in the moderate TBI group with GSC score of 9-13. The results also showed that 80% (20 patients) of the patients were age 40 years and below and 84% (21 patients) were males. In conclusion, present data show that prolactin, cortisol and plasma glucose are disturbed in TBI. The disturbances in the levels of prolactin and glucose are related to the severity of TBI. However, there is no direct relationship between cortisol and severity of TBI. Our results also show that TBI is more common in males and young people

Physico-mechanical properties of cement bonded ceiling board developed from teak and African locust bean tree wood residue

Over the years, the pursuit for locally sourced economical and environmentally safe materials has been on the increase in the development of composite boards. These locally sourced materials are organic materials from plants and livestock such as wood residue, feathers, rice husk, maize husk and bamboo fiber. Therefore, this study utilizes species of wood residue in the development composite ceiling boards. Ceiling boards were developed from teak and African locust bean tree wood residue using cement as a binder. The ceiling boards were made by varying the composite mass of the mix and mixing ratio of wood dust to cement. A constant load of 5 kN was used for the compaction process using a hydraulic pressing machine. Physico-mechanical properties of the ceiling boards such as moisture content, density, water absorption, drying shrinkage, tensile strength, and compressive strength were evaluated. The percentage of moisture content were 9.50 and 14.50% for teak and African locust bean tree wood dust, respectively. The values of density varied from 0.56 � 0.68 g/cm3. The water absorption ranged from 9.0 to 39.8% after 24 h immersion and drying shrinkage ranged from 8.60 to 35%. The maximum impact energy obtained is 98 J. The highest tensile, compressive and flexural strengths for the ceiling boards were 1.09, 0.82, and 0.56 MPa, respectively. The composite samples showed that ceiling boards made from teak wood dust is most suitable for interior use. Cement was found to be suitable as a binder for the development of ceiling boards

Design and construction of a shrimp hatchery for the breeding of the black tiger shrimp Penaeus monodon

A shrimp hatchery for the breeding of the black tiger shrimp, Penaeus monodon was constructed by the Nigeria Institute for Oceanography and Marine Research in 2008 by the reconstruction of an existing old shrimp hatchery. The new shrimp hatchery comprises of the following: water treatment, water storage, broodstock maturation, spawning/incubation, nursery and micro-algae units. The design included the construction of a concrete sump for the collection and treatment of wastewater before disposal, in addition to an aeration unit equipped with root blower for adequate supply of dissolved oxygen. The reconstructed NIOMR shrimp hatchery has been successfully used for the production of post larvae, which are presently being reared to adult shrimp in concrete tanks. The successful completion of the shrimp hatchery and breeding of P. monodon has confirmed that the species can be spawned and reared to adult size in Nigeria for local and export markets

AN INVESTIGATION OF THE EFFECTS OF POOR SPECIFICATION ON BUILDING COLLAPSE IN NIGERIA

This paper examines the effects of specification on building collapse in Nigeria. The study became necessary due to the ugly cases of buildings collapsing in the country over the years. In doing so, the study begins with review of relevant literature on the concept of specification, as well as the factors associated with building collapse. The need for specification in building construction projects was enunciated upon. Other factors that culminate in building collapse, such as load types; man-power; technical skills, etc. are discussed herein. The study further examines identifies and documents cases of building collapse in Nigeria to identify the causes and factors responsible for the collapse. Interviews were conducted with practicing professionals in the construction industry. This was done to obtain professional insights and experiences used as part of the data in the research. Findings from this study highlights consequential role of poor specification in causing building collapse, loss of lives and properties. This paper concludes with identifying the relevance of specification in ensuring adherence to appropriate materials and construction methods for structural stability. Recommendations are given to guard against poor specifications that result in the collapse of buildings, properties and ultimately loss of lives