Cost Optimization of Sandcrete Blocks through Partial Replacement of Sand with Lateritic Soil

This work finds a way in which lateritic soil within Ota, Ogun State of Nigeria could be used in the production of hollow sandcrete blocks. This replacement is intended to develop more economic sandcrete blocks since the cost of lateritic soil in Ota is much less than the cost of the conventional fine aggregate used in the production of sandcrete blocks without compromising the intergrity of the blocks. It was deduced from literatures that inclusion of lateritic soil in sandcrete block production results in a lesser quality blocks. However, this work found the maximum permissible replacement that still makes the blocks to be within the recommended standard. The blocks were produced with each lateritic soil sample from different sources replacing sand in steps of ten percent to 60% and their compressive strengths determined and compared with that of a standard sandcrete block to check for the acceptable percentage replacement. In the compressive strength test, 72 numbers of 225 x 225 x 450mm hollow laterised sandcrete block sizes were produced, cured and crushed to determine their twenty-eight-day compressive strength. Cost analysis was performed discovered that the inclusion of the lateritic soil saves the cost of production by 11.89%. This percentage replacement can be recommended to the block moulding industries within Ota with a view to reducing the production costs of the blocks

Preliminary Phytochemical and Anti-Bacterial Studies on the Leaf Extracts of Plumeria Rubra Linn

Preliminary phytochemical screening and anti-bacterial activity of dried leaf extracts of Plumeria rubra using three solvent in the order of polarity (hexane, ethyl acetate and methanol) was investigated. The phytochemical screening performed on the crude extracts revealed that the three extracts contained saponins and steroids. Tannins in ethylacetate and methanol extracts. Cardiac glycosides in ethylacetate extract, phlobatannins, flavonoids, terpenes and reducing sugar in methanol extract. The crude extracts were tested for their anti-bacterial activity on some pathogenic bacteria. Almost all the crude extracts displayed higher inhibitory effects at the tested concentration (20mg/ml), against four species of Gram negative (klesbsieva pneumonia, Pseudomonas aeruginosa, Escherichia coli, Pseudomonas fluorescence) and ten Gram positive (Bacillus subtils, Staphlococcus aureus, Clostridium sporogenes, Staphlococcus epiderm, Bacillus stearothermophilus, Bacillus cereus, Bacillus anthracis, Streptococcus faecalis, Corynebacterium phyogenes, and Bacillus polymyxa) bacterial strains; hexane and methanol extracts were the most active of the three extracts of Plumeria rubra leaf. Keywords: Phytochemical screening, anti-bacterial activity, Plumeria rubra

Preliminary Phytochemical and Anti-Bacterial Studies on the Leaf Extracts of Plumeria Rubra Linn

Preliminary phytochemical screening and anti-bacterial activity of dried leaf extracts of Plumeria rubra using three solvent in the order of polarity (hexane, ethyl acetate and methanol) was investigated. The phytochemical screening performed on the crude extracts revealed that the three extracts contained saponins and steroids. Tannins in ethylacetate and methanol extracts. Cardiac glycosides in ethylacetate extract, phlobatannins, flavonoids, terpenes and reducing sugar in methanol extract. The crude extracts were tested for their anti-bacterial activity on some pathogenic bacteria. Almost all the crude extracts displayed higher inhibitory effects at the tested concentration (20mg/ml), against four species of Gram negative (klesbsieva pneumonia, Pseudomonas aeruginosa, Escherichia coli, Pseudomonas fluorescence) and ten Gram positive (Bacillus subtils, Staphlococcus aureus, Clostridium sporogenes, Staphlococcus epiderm, Bacillus stearothermophilus, Bacillus cereus, Bacillus anthracis, Streptococcus faecalis, Corynebacterium phyogenes, and Bacillus polymyxa) bacterial strains; hexane and methanol extracts were the most active of the three extracts of Plumeria rubra leaf. Keywords: Phytochemical screening, anti-bacterial activity, Plumeria rubra

Deregulation of the Nigerian Telecommunication Sector: Interrogating the Nexus Between Imperialism and Development

This study investigates the deregulation of the Nigerian Telecommunication Sector within the precinct of Imperialism and development. This is premised on the fact that Nigeria’s Telecommunication sector has not only been moribund over the years but has more importantly been dominated by foreign and local bourgeoisies after its deregulation in 1999. In view of this, the study borrows from Structural Imperialism which argues that the elites in the Centre and Periphery states connive, indeed conspire to undermine development in the latter. It relies heavily on the use of secondary data, by virtue of the nature of the work, thus probing the dynamics of these Centre/Periphery trajectories. Findings reveal that certain levels of development have been recorded in the Telecommunication sector particularly in terms of contribution to the Nigerian economy through the ubiquitous provision of telecommunication lines, especially the mobile phones. Similarly, jobs have been created within this sector in terms of its contribution to Nigeria’s GDP profile. However, beneath these efforts, the predatory and materialistic character of the foreign and local bourgeoisie, a permanent feature of the post-colonial Nigerian state remains the greatest bane of the growth of this sector. The study concludes that until this “unholy alliance” between the foreign and local bourgeoisies is demolished, the deregulation effort of the federal government will remain a mirage. To this end, it recommends an immediate measure to increase the legislative oversight of the regulatory body, Nigerian Communication Commission (NCC) over the activities of the foreign mobile operators in Nigeria, while not neglecting, indeed promoting the indigenous operators of the telecommunication services in the countr

Geophysical Investigation of the Causes of Borehole Failure in the Crystaline Basement Complex: A Case Study of Kaura Area of Kaduna State, Nigeria

Vertical Electrical Soundings (VES) using Schlumberger array were carried out at different points along five (5) profiles. This research investigates the causes of massive borehole failure at Kaura area of Kaduna state using the resistivity tomography techniques. Terrameter SAS300 is the instruments used to acquire the data. A total of 19 boreholes are functioning, while 31 boreholes are non-functioning within the area. The investigation has portrayed the possible factors which are most probably causative to borehole failures in the area which involves the design and construction, groundwater potential/hydrogeological factors and operational and maintenance factors. It was found out that it is possible for one factor to lead to the other. For example, a borehole poorly designed, constructed and completed could result in sand/clay pumping and eventually affect the rubber seals in the hand pumps or the impellers in the case of submersible pumps. The boreholes tap the weathered and fractured basement aquifers of the area with yields ranging from 2litre/min to 20litre/min. However, yields from Sandy soil aquifers were found to be extensive. The survey shows that boreholes with initial recorded yield less than 10litre/min have failed over time. The survey reveals that the areas where wells and boreholes are drilled through sandy soil and fracture zones have sustainable aquifers for groundwater exploitation, while boreholes that are constructed through clayey formation usually fail. Keywords: Resistivity1, Kaura2, Borehole failur

Interpretation of Geoelectric Pseudo-Section of a Profile Across a Functional Borehole Located in-between Two Non-Functional Dug-Wells

Electrical resistivity imaging survey was carried at Agban, Kaura Area of Kaduna State Nigeria. A profile of 500m length was deliberately selected to cut across a functional borehole located averagely 100m in-between two non-functional dug-wells. Ten (10) VES Points were sounded along the profile in the N-S direction. Terrameter SAS300 was the instrument used. The tomogram of the profile shows that the area is underlain by four layers; the first layer is sandy clay with resistivity range of 200-500Ωm. This is taken as the Overburden. The second layer is the weathered basement which constitutes of Sandy soil and water. This is taken to be the aquifer which varies along the profile. The third layer comprise of coarse grain sand which is the fractured basement of resistivity range of 1000-2000Ωm. The fourth layer of resistivity greater than 2000Ωm is the fresh basement. The image also shows a U-shaped fracture zone within the subsurface, the borehole was drilled through this fracture which contains water. This fracture causes water to migrate from the locations of the wells and accumulate at the borehole site. This research has gone a long way to establish the facts that since the dug wells are shallow; they failed at the end of the dry season when groundwater levels fall. It is a common knowledge that little specialist equipment is used for the construction of a well even though it is difficult to construct hand dug wells in hard rock. On the basis of the results of this study, we therefore recommend that thorough geophysical survey should always be carried out in the basement complex before constructing dug wells for them to be sustainable. Keywords: Resistivity1, Kaura2, Wel

Geophysical Investigation of the Causes of Borehole Failure in the Crystaline Basement Complex: A Case Study of Kaura Area of Kaduna State, Nigeria

Vertical Electrical Soundings (VES) using Schlumberger array were carried out at different points along five (5) profiles. This research investigates the causes of massive borehole failure at Kaura area of Kaduna state using the resistivity tomography techniques. Terrameter SAS300 is the instruments used to acquire the data. A total of 19 boreholes are functioning, while 31 boreholes are non-functioning within the area. The investigation has portrayed the possible factors which are most probably causative to borehole failures in the area which involves the design and construction, groundwater potential/hydrogeological factors and operational and maintenance factors. It was found out that it is possible for one factor to lead to the other. For example, a borehole poorly designed, constructed and completed could result in sand/clay pumping and eventually affect the rubber seals in the hand pumps or the impellers in the case of submersible pumps. The boreholes tap the weathered and fractured basement aquifers of the area with yields ranging from 2litre/min to 20litre/min. However, yields from Sandy soil aquifers were found to be extensive. The survey shows that boreholes with initial recorded yield less than 10litre/min have failed over time. The survey reveals that the areas where wells and boreholes are drilled through sandy soil and fracture zones have sustainable aquifers for groundwater exploitation, while boreholes that are constructed through clayey formation usually fail. Keywords: Resistivity1, Kaura2, Borehole failur

The Influence of Training on Bricklayers’ Productivity in Nigeria

The global economic situation and the need for construction contractors to remain in business in this competitive environment have made productivity improvement more and more important. This study therefore investigated the impact of formal and informal trainings on the productivity of bricklayers in three commercial nerve centres of Nigeria (Lagos, Abuja and Port Harcourt).To achieve this, questionnaires, backed up with interviews and on-site measurements were conducted on the management and bricklayers of construction firms who were randomly drawn from the three categories of construction firms in the country (large-sized, medium-sized and small-sized firms). 90 and 180 structured questionnaires were distributed to the management and bricklayers in the study area while 72 and 118 questionnaires were respectively filled and returned in this regard. The results of the descriptive and inferential statistical techniques indicated that training had significant effect on the productivity of bricklayers in Nigeria. Other factors such as monetary and nonmonetary incentives, planning and control, organizational strategy, supervision aspects and general management also had their contributory effects to bricklayers’ productivity. The study concluded that the issue of training should be accorded a priority attention by the managements of construction firms in order to attain greater workers’ productivity on construction sites

Selection shapes the landscape of functional variation in wild house mice.

BACKGROUND: Through human-aided dispersal over the last ~ 10,000 years, house mice (Mus musculus) have recently colonized diverse habitats across the globe, promoting the emergence of new traits that confer adaptive advantages in distinct environments. Despite their status as the premier mammalian model system, the impact of this demographic and selective history on the global patterning of disease-relevant trait variation in wild mouse populations is poorly understood. RESULTS: Here, we leveraged 154 whole-genome sequences from diverse wild house mouse populations to survey the geographic organization of functional variation and systematically identify signals of positive selection. We show that a significant proportion of wild mouse variation is private to single populations, including numerous predicted functional alleles. In addition, we report strong signals of positive selection at many genes associated with both complex and Mendelian diseases in humans. Notably, we detect a significant excess of selection signals at disease-associated genes relative to null expectations, pointing to the important role of adaptation in shaping the landscape of functional variation in wild mouse populations. We also uncover strong signals of selection at multiple genes involved in starch digestion, including Mgam and Amy1. We speculate that the successful emergence of the human-mouse commensalism may have been facilitated, in part, by dietary adaptations at these loci. Finally, our work uncovers multiple cryptic structural variants that manifest as putative signals of positive selection, highlighting an important and under-appreciated source of false-positive signals in genome-wide selection scans. CONCLUSIONS: Overall, our findings highlight the role of adaptation in shaping wild mouse genetic variation at human disease-associated genes. Our work also highlights the biomedical relevance of wild mouse genetic diversity and underscores the potential for targeted sampling of mice from specific populations as a strategy for developing effective new mouse models of both rare and common human diseases