• Environmental Engineering Research
• /
• v.24 no.2
• /
• pp.289-297
• /
• 2019

Indiscriminate disposal of waste and citation of open dumpsites are some of the key factors affecting the various soil geotechnical properties. Atterberg limit and consolidation tests were conducted to determine the effects of two open waste dumpsites (Uselu Market and New Benin) on geotechnical properties of their underlying soils. Soil sample collected from Uselu Market dumpsite in Benin City metropolis showed slightly lower hydraulic conductivity (K) of $1.0{\times}10^{-6}$ with plasticity index of 18.53% compared to sample collected 1.6 m from the same dumpsite which had high K value of $2.42{\times}10^{-3}$ with plasticity index of 6.9%. Soil sample collected from New Benin dumpsite in Benin City metropolis showed slightly lower K of $1.45{\times}10^{-6}$ with plasticity index of 13.8% than sample collected 1.6 m from the same dumpsite which had high K value of $2.14{\times}10^{-2}$ with plasticity index of 6.0%. X-ray florescent analyser (X-MET 7000) and direct soil pH meter were used to determine the composition of the aforementioned soil samples. The result of samples collected from both dumpsites indicated a low hydraulic conductivity compared to samples collected 1.6 m from both dumpsites. Also, the chemical composition and pH of both dumpsite underlying soils indicated high level of soil contaminants with pH of 3.3 and 3.5 which is very acidic unlike pH of other samples which were in the neutral range (6.8-7.1). Hence, a liner is recommended for all dumpsites or engineered landfill systems to mitigate against the challenges associated with open waste dumping system in the environment.

• Journal of the Korean Chemical Society
• /
• v.52 no.5
• /
• pp.530-535
• /
• 2008

• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.157-157
• /
• 2022

Recent decades have seen all over the world increasing drought in some regions and increasing flood in others. Climate change has been alarming in many regions resulting in degradation and diminution of available freshwater. The effect of global warming and overpopulation associated with increasing irrigated farming and valuable agricultural lands could be particularly disastrous for coastal areas like the one of Benin. The coastal region of Benin is under a heavy demographic pressure and was in the last decades the object of important urban developments. The present study aims to roughly study the general effect of climate change (Sea Level Rise: SLR) and groundwater pumping on Seawater intrusion (SWI) in Benin's coastal region. To reach the main goal of our study, the region aquifer system was built in numerical model using SEAWAT engine from Visual MODFLOW. The model is built and calibrated from 2016 to 2020 in SEAWAT, and using WinPEST the model parameters were optimized for a better performance. The optimized parameters are used for seawater intrusion intensity evaluation in the coastal region of Benin The simulation of the hydraulic head in the calibration period, showed groundwater head drawdown across the area with an average of 1.92m which is observed on the field by groundwater level depletion in hand dug wells mainly in the south of the study area. SWI area increased with a difference of 2.59km² between the start and end time of the modeling period. By considering SLR due to global warming, the model was stimulated to predict SWI area in 2050. IPCC scenario IS92a simulated SLR in the coastal region of Benin and the average rise is estimated at 20cm by 2050. Using the average rise, the model is run for SWI area estimation in 2050. SWI area in 2050 increased by an average of 10.34% (21.04 km²); this is expected to keep increasing as population grows and SLR.

• The Korean Journal of Mycology
• /
• v.16 no.4
• /
• pp.207-209
• /
• 1988

Sporocarps of Pleurotus tuber-regium Fr. were subjected to aerial and substrate(soil) watering sytems. Although aerial watering enhanced quick enlargment of pilei, those watered indirectly through the soil developed more naturally pigmented sporophores and with higher overall yield. Thus, substrate(soil) watering after emergence is preferred to direct watering of fruits.

• The Korean Journal of Mycology
• /
• v.19 no.4
• /
• pp.250-252
• /
• 1991

Four species of the Myxomycetes (Order Liceales) collected from Bendel State, Nigeria, and newly described; Licea kleistobolus, L. pusilla, Cribraria lepida and Dictydium cancellatum. All of them are new records for Nigeria.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.23 no.3
• /
• pp.179-202
• /
• 2019

This paper presents second derivative generalized extended backward differentiation formulas (SDGEBDFs) based on the second derivative linear multi-step formulas of Cash [1]. This class of second derivative linear multistep formulas is implemented as boundary value methods on stiff problems. The order, error constant and the linear stability properties of the new methods are discussed.

• The Korean Journal of Mycology
• /
• v.16 no.4
• /
• pp.204-206
• /
• 1988

Chemical analysis of both sclerotia and the fruits of Pleurotus tuber-regium showed higher values for such elements as calcium(Ca), iron(Fe), zine(Zn) in the fruits than in the sclerotia. On the contrary magnessium(Mg) was found to be higher in sclerotia than in the fruits. protein and carbohydrate were also found to be more in the fruits. There was no significant difference between the chemical values of old(1 year) and fresh sclerotia. Oil palm fruit fibre substrate produced sporophores with higher values for the minerals, protein and carbohydrate than those on riversand substrate.

• Korean Journal of Remote Sensing
• /
• v.37 no.4
• /
• pp.803-813
• /
• 2021

Coastal erosion has been a threat to coastal communities and emerged as an urgent problem. Among the coastal communities that are under perceived threat, Cotonou located in Benin, West Africa, is considered as one of the most dangerous area due to its high vulnerability. To address this problem, in 2013, the Benin authorities established seven groynes at east of Cotonou port, and two additional intermediate groynes have recently been integrated in April 2018. However, there is no quantitative analysis of groynes so far, so it is hard to know how effective they have been. To analyze effectiveness, we used optical satellite images from different time periods, especially 2004 and 2020, and then compared changes in length, width and area of shoreline in Cotonou. The study area is divided into two sectors based on the location of Cotonou port. The difference of two areas is that Sector 2 has groynes installed while Sector 1 hasn't. As result of this study, shoreline in Sector 1 showed accretion by recovering 1.20 km² of area. In contrast, 3.67 km² of Sector 2 disappeared due to coastal erosion, although it has groynes. This may imply that groynes helped to lessen the rate of average erosion, however, still could not perfectly stop the coastal erosion in the area. Therefore, for the next step, we assume it is recommended to study how to maximize effectiveness of groynes.

• Parasites, Hosts and Diseases
• /
• v.52 no.2
• /
• pp.177-181
• /
• 2014

Cockroaches are abundant in Nigeria and are seen to harbour an array of pathogens. Environmental and sanitary conditions associated with demographic/socio-economic settings of an area could contribute to the prevalence of disease pathogens in cockroaches. A total of 246 cockroaches (Periplaneta americana) in urban (Benin, n=91), semi-urban (Ekpoma, n=75) and rural (Emuhi, n=70) settings in Edo State, Nigeria were collected within and around households. The external body surfaces and alimentary canal of these cockroaches were screened for bacterial, fungal, and parasitological infections. Bacillus sp. and Escherichia coli were the most common bacteria in cockroaches. However, Enterococcus faecalis could not be isolated in cockroaches trapped from Ekpoma and Emuhi. Aspergillus niger was the most prevalent fungus in Benin and Ekpoma, while Mucor sp. was predominant in Emuhi. Parasitological investigations revealed the preponderance of Ascaris lumbricoides in Benin and Emuhi, while Trichuris trichura was the most predominant in Ekpoma. The prevalence and burden of infection in cockroaches is likely to be a reflection of the sanitary conditions of these areas. Also, cockroaches in these areas making incursions in homes may increase the risk of human infections with these disease agents.

• Fisheries and Aquatic Sciences
• /
• v.26 no.4
• /
• pp.256-267
• /
• 2023

The suitability of any fish species for successful aquaculture requires basic information on its reproduction and growth. This study investigated some facets of the reproductive biology of Synodontis shall (Mochokidae) from River Siluko in Nigeria. Fish samples were collected forth-nightly for a duration of fourteen (14) months-March 2015 to April, 2016 with the assistance of artisanal fishermen. Fishes were identified using taxonomic guides and standard techniques were used for determination of sex ratio, gonad maturation and fecundity. Linear regression method was used to define the correlation between fecundity and fish length, body weight and ovary weight. Results showed that sex ratio did not indicate a significant divergence (p > 0.05) from the 1 male to 1 female distribution ratio (1:1.41). Gonad morphology revealed paired gonads. Testes and ovaries were classified into four maturity stages: immature, resting, ripening and ripe. Gonadosomatic index ranged from 0.04 to 5.68 (males) and 0.03 to 20.19 (females). Absolute fecundity ranged from 1,014 to 4,520 eggs (mean = 2,592 eggs) and did not correlate significantly (p > 0.05) to ovary weight. This study has contributed to existing data on the biology of freshwater fish species in Nigeria and provided valuable information for fishery management tools in the conservation and utilization of this valuable freshwater fish species.