Search

The establishments of the nexus between the underlying geology and engineering properties are fundamentals to the safe, economic and serviceable designs of civil engineering structures. Cone Penetration Test (CPT) and Electrical Resistivity Tomography (ERT) are critical tools in foundation parameterization especially within Quaternary sediments serving as foundation of engineering structures. Both techniques were used to obtained point data and lateral continuity of geologic units within Ikate Area of Lagos Metropolis for foundation parameterization. Measurements which comprising 4 profiles of 2D resistivity imaging using the Wenner electrode configuration; 1 borehole and 12 cone penetration tests (CPT) were taken with Pasi Terrameter, percussion rig and the 10.0 tons penetrometer respectively. The ERT results interpreted using Dipro software were presented in Pseudo-sections while the cone penetration test results analysed with Microsoft Excel were represented as resistance curves. Interpretation from the two methods integrated with the borehole results reveals the presence clay, peat and sand of varying properties. The uppermost layer consists of medium dense sand followed by clay/peat of very low resistivity (< 3.5 ohm-meter) covering about 6. 0 – 8.0m in depth and terminating in another layer of sand (8.0 – 15.0m). The last sandy layer with cone resistance range between 30 – 120kg/cm2 is considered a suitable layer upon which deep foundation may be founded. Shallow foundation capacity estimates at depths 0.2 – 4.0m derived from direct CPT data using three different computation techniques gives value range from 1.7 – 49.4kg/cm2, 0.7 – 15.2kg/cm2 and 0.4 – 12.6kg/cm2 respectively. Deep foundation for skyscrapers within the area are advised to be founded within the competent layer encountered beyond 10.m depth.

Assessment of groundwater potential of Iperindo area, Southwestern Nigeria was conducted by mapping spatial distribution of groundwater availability within the area and consequently locating areas of groundwater reserve to serve the community and its environs. This was achieved by integrating geophysical techniques involving landsat ETM-7 satellite data, aeromagnetic data, VLF-EM and electrical resistivity methods to delineate subsurface structures, understand the direction of groundwater flow, and detect the depth to groundwater aquifer. The result of landsat and aeromagnetic revealed some lineament intersection approximately NE-SW direction and interpreted to be potential sites for groundwater development. VLF-EM revealed geologic structures of significant hydrogeological importance at depths of 40 m to 200 m. Vertical electrical sounding (VES) confirmed high groundwater prospect in the areas with estimated depth to water table between 30 m and 100 m. The integrated results of the study revealed adequate groundwater spatial distribution for effective groundwater development in the area.

Electronic Health Records (EHRs) are one of the exploding innovations in the twenty-first century. It serves as the backbone of medical operations in the developed countries. However, many developing countries including sub-Saharan Africa are yet to incorporate EHRs, despite the multiplicity of benefit it offers. This paper presents a design model that can be implemented in these economies. A work flow of operations in a typical hospital was defined and used in the design process. The patients’ data are captured through the front end application and these were stored on the database. A role based access level is assigned to caregiver through the incorporated fingerprint access control. All the caregivers’ workstations are connected to the EHRs via a configured server. The designed EHR system will enable optimization of clinical practices and management functions when deployed. The system is affordable to clinics and hospitals in the developing world. It can be adapted to meet the specific goals or requirements of an organization. Keywords: Health record, Healthcare, Hospital workflow, Electronic medical record

Gold mining operations started in the Ilesa-West Local Government Area of Osun state Nigeria in early 1950s. Though official mining operation stopped in mid 1990s, illegal mining is still active in the area till today. Twelve (12) villages were selected for the study based on the high rate of mining activities. The villages are Mokuro, Oke-Ora, Okutu-Omo, Oko Ogboni, Alaba, Itagunmodi, Ariyelepe, Alaba-Oke, Iyere, Igun, Aba-Isobo and Sabo, all in Ilesa South West Local Government area of Osun state, Nigeria within longitude 40 361 - 40 421 E and latitude 70 301 - 70 341 N. A total of 51 stream water and sediment samples were randomly collected from water sources available to the communities. Stream water samples collected were analyzed for heavy metals using atomic absorption spectrophotometer (AAS) while associated stream sediments were analyzed with x-ray fluorescence spectrometer (XRF). Heavy metals analyzed in both sample types include As, Cu, Cd, Pb, Fe, Cr, Mn, Zn, Zr, and Sr. Results obtained showed the stream waters to be richly concentrated with toxic metals in the range of As(0.002± 0.001 to 0.004± 0.001 mg/l), Cd (0.003±0.001 to 0.034± 0.004 mg/l), Pb (0.002± 0.001 to 0.017±0.003mg/l), Cu(0.078±0.003 to 2.326±0.004 mg/l), Zn(0.013 ±0.004 to 1.937±0.015mg/l), Fe (0.013±0.005 to 0.825±0.085mg/l), Mn (0.002±0.001 to 0.016±0.001mg/l) and Cr (0.009 ± 0.002 to 0.069 ± 0.031mg/l). The variation of heavy metals in stream water samples are Cu>Zn>Cr>Fe>Cd>As>Pb>Mn. Similar contamination of the stream sediments were observed as XRF results showed the sediments to have high concentration of heavy metals As, Cd, Pb ,Cu and Cd clearly above regulated limits. Enrichment Factor of the elements obtained showed high contamination of both the stream water and sediments with toxic metals as a result of high illegal gold mining operations in the area under study.

Effluent and sediment samples were collected on seasonal basis, comprising of three months (August to October, 2014) in the wet season and three months (December 2014 to February 2015) in the dry season from five points around a lubricating oil company in Osogbo - Nigeria. The sequential extraction method was used to respectively fractionate the sediment and effluent samples, then analyzed by Atomic Absorption Spectrophotometry (AAS) to determine concentrations of five heavy metals: Mn, Ni Co, Cd and Pb. Results showed that in wet season, higher concentration of Mn was found in exchangeable fraction, Ni and Pb were more pronounced in carbonate bound fraction, Cd in Fe-Mn oxide fraction, while Co was more in residual fraction. In dry season, Pb was more concentrated in exchangeable fraction, Co in residual fraction, Mn in Fe-Mn oxide fraction, Cd in organic matter bound, while Ni was more concentrated in the carbonate fraction. In both seasons for sediment samples, Cd concentrations were found above the set limit by WHO. The speciation study of the effluent showed that, Mn, Co and Ni concentration were found more in Organic substances fraction in both seasons, Pb was more concentrated in free metal ion fraction in wet season while it was high in organic fraction in the dry season. Concentrations of all metals in the effluent samples in both seasons were above the maximum permissible limit for effluent. The high mobility factors of heavy metals in the sediment indicated that the metals were labile and bioavailable thereby making the soil and the living organisms vulnerable to possibility of high heavy metal bioaccumulation. [ABSTRACT FROM AUTHOR]

Soils around petroleum products retailing stations were analyzed for their physicochemical, elemental, and total petroleum hydrocarbon contents with a notion to assess the contamination level of the soils. Samples were collected using standard analytical procedures and the elemental contents of the soils were determined using bulk scientific atomic absorption spectrometry/atomic emission spectrometry techniques, while total petroleum hydrocarbon and physicochemical parameters contents were determined using standard analytical techniques. Ten elements were analyzed and detected and their concentrations, enrichment factors, pollution index, and geoaccumulation index (Igeo) values established. The concentrations of most of the analyzed elements were higher in the oil-contaminated soils than those of other Nigerian soils, while the values of the analyzed physicochemical parameters followed the same trend. The results of the Igeoindicated that the soils werevery heavily polluted(6.2–18.0) with all the metal, except V, which washeavily polluted(4.2). Very high enrichment factors and pollution index were obtained for Mn, Zn, K, Cu, Ni, Cr, and Pb. This was corroborated by their values, which were excessive when compared with their tolerable limits. The clustering results indicated that the elements were fairly correlated, indicating chemical affinity and/or similar sources. These were supported by the cross plot results (R2= 0.5), and the results of Pearson correlation matrices for the elements. Average total petroleum hydrocarbons level (1,233.0 mg/kg) of the soils was high when compared to studies of similar settings. The overall results showed that the soils were highly contaminated and may pose a threat to public health. [ABSTRACT FROM AUTHOR]

Oil contaminated soils around refined petroleum products depot and retailing stations were investigated for selected polycyclic aromatic hydrocarbons (PAHs) to determine their levels in the soils. Soil samples were collected using standard analytical procedures and the petroleum hydrocarbons extracted using standard method, while the PAHs (benzo[a]pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, and anthracene) contents of the extracted petroleum hydrocarbons were determined using SNR 8126 gas chromatograph equipped with a flame ionization detector (FID). The results indicated that benz[a]anthracene has the highest concentrations in both the oil depot contaminated soils (59.1 ± 3.3 mg/kg) and oil retailing station contaminated soils (20.8 ± 2.1 mg/kg). The results also showed that the oil depot contaminated soils were burdened with the analyzed PAHs than oil retailing station contaminated soils; this was confirmed by the results ofttest analysis. Comparison of the values of the PAHs in the oil impacted soils with their background levels showed that their values in the two sets of oil impacted soils were excessive; this was corroborated with their high pollution (PI) and geoaccumulation (Igeo) index values, except chrysene, whichmoderately pollutedthe soils (low PI and Igeovalues); this was clear indication of indiscriminate discharge of petroleum fuels and petrochemicals into the soils. [ABSTRACT FROM AUTHOR]

Samples of used and unused (control sample) lubricating oil were subjected to wear metal analysis using the graphite furnace atomic absorption spectrophotometry technique (Model ALPH 4) and were also analyzed for functional groups of compound types present in them using infrared spectrophotometer (Buck Model M500). Concentrations of nine metals-Cr, Mn, Fe, Ni, Cu, Zn, Cd, Mg, and Pb in the samples were determined to ascertain environmental degradation ability of the used oils. As expected, the concentrations of the metallic species were found to be higher in used oil than unused oil. Also Cu, Pb, and Cd, which are known to be toxic at excessive levels, were found to be highly enriched (E.F. > 10) in the used lubricating oils. Infrared peaks of aromatics, alkanes, aldehydes, alcohol, and esters were shown in the lubricating oils indicating that they contain hazardous organic compounds that can cause ill-health in humans and animals. [ABSTRACT FROM AUTHOR]

Industrial evolution in developing countries, most especially Nigeria in the last century, has resulted in geometrical increase in waste generation compared to the arithmetic progress in management methods, thereby creating the problem of effective waste management and disposal. Wastes generated from industries have become a major source of pollution of groundwater when contaminants become leached into the groundwater. Water samples collected from 44 wells within 25 m radius from six refuse dump sites within Lagos metropolis during the months of February and September, 2006 were analyzed for nine heavy metals, namely, Lead (Pb), Chromium (Cr), Zinc (Zn), Cadmium (Cd), Nickel (Ni), Cobalt (Co), Iron (Fe), Manganese (Mn) and Copper (Cu), using AAS according to standard procedures. The results showed elevated concentrations of most heavy metals determined. Pb, Cd, Mn and Fe have their concentrations clearly above the World Health Organization (WHO) and Standard Organization of Nigeria (SON) recommended limit for potable water, showing contamination from the refuse dumps, while the concentrations of Cu and Zn were below toxic levels for drinking water in all the samples. Co was not detected in most of the samples, while the concentration of Ni detected was also quite low except at one of the sites where it was above the recommended level. [ABSTRACT FROM AUTHOR]

Geophysical and geotechnical methods remain one of the most effective approaches for the evaluation of subsoil properties prior to engineering construction. This is important in the delineation of soil sequence and estimation of soil parameters necessary for ensuring sufficient supports for structures. This study therefore presents the results of subsoil integrity and corrosivity probability evaluation using Vertical Electrical Sounding (VES) and Standard Penetration (SPT) in Ikate Area, Lagos, Nigeria. Data were acquired in eight (8) VES positions using Pasi terameter deploying the Schlumberger array system along four traverses while SPT-N values were obtained at every 1.5m within six (6) boreholes drilled to 30.0m depth in the study area. The combined results of VES and SPT delineate four to five geologic units corresponding to topsoil, different shades of clays, peat, sandy/clayey sand and sand. The low resistivity values of the clayey, peaty, and sandy layers especially along traverse four was used to rate them as highly or extremely susceptible to corrosion. The presence of highly compressible organic clay and peat in the second layer precludes the adoption of shallow foundation in the medium dense sandy layer that made up the topsoil (0.0 – 2.50m). Foundation analysis carried out with N-values shows that pile installed within the clayed sand/sand clay and sand layers encountered between 12.0 – 27.m with diameter range of 300 – 600mm could mobilize ultimate and allowable loads ranges of [702.9 – 5012.4KN] and [234.3 – 1670.8KN]. The correlations of resistivity with N-values returned high to weak positive linear relationships suggesting that resistivity values may not be effective in estimation of the strength and stiffness of subsoil. Conclusively, the study demonstrated the complimentary role of both VES and SPT as an effective geoengineering characterization tool.